![Filipe Brandenburger](/assets/img/avatar_default.png)
Sometimes the cleanup after memcg hierarchy testing gets stuck in
mem_cgroup_reparent_charges(), unable to bring non-kmem usage down to 0.
There may turn out to be several causes, but a major cause is this: the
workitem to offline parent can get run before workitem to offline child;
parent's mem_cgroup_reparent_charges() circles around waiting for the
child's pages to be reparented to its lrus, but it's holding
cgroup_mutex which prevents the child from reaching its
mem_cgroup_reparent_charges().
Further testing showed that an ordered workqueue for cgroup_destroy_wq
is not always good enough: percpu_ref_kill_and_confirm's call_rcu_sched
stage on the way can mess up the order before reaching the workqueue.
Instead, when offlining a memcg, call mem_cgroup_reparent_charges() on
all its children (and grandchildren, in the correct order) to have their
charges reparented first.
Fixes: e5fca243ab
("cgroup: use a dedicated workqueue for cgroup destruction")
Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org> [v3.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7337 lines
194 KiB
C
7337 lines
194 KiB
C
/* memcontrol.c - Memory Controller
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*
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* Copyright IBM Corporation, 2007
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* Author Balbir Singh <balbir@linux.vnet.ibm.com>
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*
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* Copyright 2007 OpenVZ SWsoft Inc
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* Author: Pavel Emelianov <xemul@openvz.org>
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*
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* Memory thresholds
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* Copyright (C) 2009 Nokia Corporation
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* Author: Kirill A. Shutemov
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*
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* Kernel Memory Controller
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* Copyright (C) 2012 Parallels Inc. and Google Inc.
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* Authors: Glauber Costa and Suleiman Souhlal
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/res_counter.h>
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#include <linux/memcontrol.h>
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#include <linux/cgroup.h>
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#include <linux/mm.h>
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#include <linux/hugetlb.h>
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#include <linux/pagemap.h>
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#include <linux/smp.h>
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#include <linux/page-flags.h>
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#include <linux/backing-dev.h>
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#include <linux/bit_spinlock.h>
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#include <linux/rcupdate.h>
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#include <linux/limits.h>
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#include <linux/export.h>
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#include <linux/mutex.h>
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#include <linux/rbtree.h>
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#include <linux/slab.h>
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#include <linux/swap.h>
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#include <linux/swapops.h>
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#include <linux/spinlock.h>
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#include <linux/eventfd.h>
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#include <linux/poll.h>
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#include <linux/sort.h>
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#include <linux/fs.h>
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#include <linux/seq_file.h>
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#include <linux/vmpressure.h>
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#include <linux/mm_inline.h>
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#include <linux/page_cgroup.h>
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#include <linux/cpu.h>
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#include <linux/oom.h>
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#include <linux/lockdep.h>
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#include <linux/file.h>
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#include "internal.h"
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#include <net/sock.h>
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#include <net/ip.h>
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#include <net/tcp_memcontrol.h>
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#include "slab.h"
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#include <asm/uaccess.h>
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#include <trace/events/vmscan.h>
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struct cgroup_subsys mem_cgroup_subsys __read_mostly;
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EXPORT_SYMBOL(mem_cgroup_subsys);
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#define MEM_CGROUP_RECLAIM_RETRIES 5
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static struct mem_cgroup *root_mem_cgroup __read_mostly;
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#ifdef CONFIG_MEMCG_SWAP
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/* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
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int do_swap_account __read_mostly;
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/* for remember boot option*/
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#ifdef CONFIG_MEMCG_SWAP_ENABLED
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static int really_do_swap_account __initdata = 1;
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#else
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static int really_do_swap_account __initdata = 0;
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#endif
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#else
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#define do_swap_account 0
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#endif
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static const char * const mem_cgroup_stat_names[] = {
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"cache",
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"rss",
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"rss_huge",
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"mapped_file",
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"writeback",
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"swap",
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};
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enum mem_cgroup_events_index {
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MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */
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MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */
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MEM_CGROUP_EVENTS_PGFAULT, /* # of page-faults */
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MEM_CGROUP_EVENTS_PGMAJFAULT, /* # of major page-faults */
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MEM_CGROUP_EVENTS_NSTATS,
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};
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static const char * const mem_cgroup_events_names[] = {
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"pgpgin",
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"pgpgout",
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"pgfault",
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"pgmajfault",
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};
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static const char * const mem_cgroup_lru_names[] = {
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"inactive_anon",
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"active_anon",
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"inactive_file",
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"active_file",
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"unevictable",
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};
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/*
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* Per memcg event counter is incremented at every pagein/pageout. With THP,
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* it will be incremated by the number of pages. This counter is used for
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* for trigger some periodic events. This is straightforward and better
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* than using jiffies etc. to handle periodic memcg event.
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*/
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enum mem_cgroup_events_target {
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MEM_CGROUP_TARGET_THRESH,
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MEM_CGROUP_TARGET_SOFTLIMIT,
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MEM_CGROUP_TARGET_NUMAINFO,
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MEM_CGROUP_NTARGETS,
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};
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#define THRESHOLDS_EVENTS_TARGET 128
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#define SOFTLIMIT_EVENTS_TARGET 1024
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#define NUMAINFO_EVENTS_TARGET 1024
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struct mem_cgroup_stat_cpu {
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long count[MEM_CGROUP_STAT_NSTATS];
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unsigned long events[MEM_CGROUP_EVENTS_NSTATS];
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unsigned long nr_page_events;
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unsigned long targets[MEM_CGROUP_NTARGETS];
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};
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struct mem_cgroup_reclaim_iter {
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/*
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* last scanned hierarchy member. Valid only if last_dead_count
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* matches memcg->dead_count of the hierarchy root group.
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*/
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struct mem_cgroup *last_visited;
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int last_dead_count;
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/* scan generation, increased every round-trip */
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unsigned int generation;
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};
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/*
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* per-zone information in memory controller.
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*/
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struct mem_cgroup_per_zone {
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struct lruvec lruvec;
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unsigned long lru_size[NR_LRU_LISTS];
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struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1];
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struct rb_node tree_node; /* RB tree node */
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unsigned long long usage_in_excess;/* Set to the value by which */
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/* the soft limit is exceeded*/
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bool on_tree;
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struct mem_cgroup *memcg; /* Back pointer, we cannot */
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/* use container_of */
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};
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struct mem_cgroup_per_node {
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struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
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};
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/*
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* Cgroups above their limits are maintained in a RB-Tree, independent of
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* their hierarchy representation
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*/
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struct mem_cgroup_tree_per_zone {
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struct rb_root rb_root;
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spinlock_t lock;
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};
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struct mem_cgroup_tree_per_node {
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struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES];
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};
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struct mem_cgroup_tree {
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struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
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};
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static struct mem_cgroup_tree soft_limit_tree __read_mostly;
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struct mem_cgroup_threshold {
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struct eventfd_ctx *eventfd;
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u64 threshold;
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};
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/* For threshold */
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struct mem_cgroup_threshold_ary {
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/* An array index points to threshold just below or equal to usage. */
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int current_threshold;
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/* Size of entries[] */
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unsigned int size;
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/* Array of thresholds */
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struct mem_cgroup_threshold entries[0];
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};
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struct mem_cgroup_thresholds {
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/* Primary thresholds array */
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struct mem_cgroup_threshold_ary *primary;
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/*
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* Spare threshold array.
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* This is needed to make mem_cgroup_unregister_event() "never fail".
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* It must be able to store at least primary->size - 1 entries.
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*/
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struct mem_cgroup_threshold_ary *spare;
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};
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/* for OOM */
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struct mem_cgroup_eventfd_list {
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struct list_head list;
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struct eventfd_ctx *eventfd;
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};
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/*
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* cgroup_event represents events which userspace want to receive.
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*/
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struct mem_cgroup_event {
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/*
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* memcg which the event belongs to.
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*/
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struct mem_cgroup *memcg;
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/*
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* eventfd to signal userspace about the event.
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*/
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struct eventfd_ctx *eventfd;
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/*
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* Each of these stored in a list by the cgroup.
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*/
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struct list_head list;
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/*
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* register_event() callback will be used to add new userspace
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* waiter for changes related to this event. Use eventfd_signal()
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* on eventfd to send notification to userspace.
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*/
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int (*register_event)(struct mem_cgroup *memcg,
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struct eventfd_ctx *eventfd, const char *args);
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/*
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* unregister_event() callback will be called when userspace closes
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* the eventfd or on cgroup removing. This callback must be set,
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* if you want provide notification functionality.
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*/
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void (*unregister_event)(struct mem_cgroup *memcg,
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struct eventfd_ctx *eventfd);
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/*
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* All fields below needed to unregister event when
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* userspace closes eventfd.
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*/
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poll_table pt;
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wait_queue_head_t *wqh;
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wait_queue_t wait;
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struct work_struct remove;
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};
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static void mem_cgroup_threshold(struct mem_cgroup *memcg);
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static void mem_cgroup_oom_notify(struct mem_cgroup *memcg);
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/*
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* The memory controller data structure. The memory controller controls both
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* page cache and RSS per cgroup. We would eventually like to provide
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* statistics based on the statistics developed by Rik Van Riel for clock-pro,
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* to help the administrator determine what knobs to tune.
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*
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* TODO: Add a water mark for the memory controller. Reclaim will begin when
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* we hit the water mark. May be even add a low water mark, such that
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* no reclaim occurs from a cgroup at it's low water mark, this is
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* a feature that will be implemented much later in the future.
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*/
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struct mem_cgroup {
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struct cgroup_subsys_state css;
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/*
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* the counter to account for memory usage
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*/
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struct res_counter res;
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/* vmpressure notifications */
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struct vmpressure vmpressure;
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/*
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* the counter to account for mem+swap usage.
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*/
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struct res_counter memsw;
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/*
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* the counter to account for kernel memory usage.
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*/
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struct res_counter kmem;
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/*
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* Should the accounting and control be hierarchical, per subtree?
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*/
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bool use_hierarchy;
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unsigned long kmem_account_flags; /* See KMEM_ACCOUNTED_*, below */
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bool oom_lock;
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atomic_t under_oom;
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atomic_t oom_wakeups;
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int swappiness;
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/* OOM-Killer disable */
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int oom_kill_disable;
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/* set when res.limit == memsw.limit */
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bool memsw_is_minimum;
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/* protect arrays of thresholds */
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struct mutex thresholds_lock;
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/* thresholds for memory usage. RCU-protected */
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struct mem_cgroup_thresholds thresholds;
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/* thresholds for mem+swap usage. RCU-protected */
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struct mem_cgroup_thresholds memsw_thresholds;
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/* For oom notifier event fd */
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struct list_head oom_notify;
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/*
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* Should we move charges of a task when a task is moved into this
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* mem_cgroup ? And what type of charges should we move ?
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*/
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unsigned long move_charge_at_immigrate;
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/*
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* set > 0 if pages under this cgroup are moving to other cgroup.
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*/
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atomic_t moving_account;
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/* taken only while moving_account > 0 */
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spinlock_t move_lock;
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/*
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* percpu counter.
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*/
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struct mem_cgroup_stat_cpu __percpu *stat;
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/*
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* used when a cpu is offlined or other synchronizations
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* See mem_cgroup_read_stat().
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*/
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struct mem_cgroup_stat_cpu nocpu_base;
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spinlock_t pcp_counter_lock;
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atomic_t dead_count;
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#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
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struct cg_proto tcp_mem;
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#endif
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#if defined(CONFIG_MEMCG_KMEM)
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/* analogous to slab_common's slab_caches list. per-memcg */
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struct list_head memcg_slab_caches;
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/* Not a spinlock, we can take a lot of time walking the list */
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struct mutex slab_caches_mutex;
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/* Index in the kmem_cache->memcg_params->memcg_caches array */
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int kmemcg_id;
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#endif
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int last_scanned_node;
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#if MAX_NUMNODES > 1
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nodemask_t scan_nodes;
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atomic_t numainfo_events;
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atomic_t numainfo_updating;
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#endif
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/* List of events which userspace want to receive */
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struct list_head event_list;
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spinlock_t event_list_lock;
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struct mem_cgroup_per_node *nodeinfo[0];
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/* WARNING: nodeinfo must be the last member here */
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};
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/* internal only representation about the status of kmem accounting. */
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enum {
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KMEM_ACCOUNTED_ACTIVE, /* accounted by this cgroup itself */
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KMEM_ACCOUNTED_DEAD, /* dead memcg with pending kmem charges */
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};
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#ifdef CONFIG_MEMCG_KMEM
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static inline void memcg_kmem_set_active(struct mem_cgroup *memcg)
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{
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set_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags);
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}
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static bool memcg_kmem_is_active(struct mem_cgroup *memcg)
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{
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return test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags);
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}
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static void memcg_kmem_mark_dead(struct mem_cgroup *memcg)
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{
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/*
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* Our caller must use css_get() first, because memcg_uncharge_kmem()
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* will call css_put() if it sees the memcg is dead.
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*/
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smp_wmb();
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if (test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags))
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set_bit(KMEM_ACCOUNTED_DEAD, &memcg->kmem_account_flags);
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}
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static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup *memcg)
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{
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return test_and_clear_bit(KMEM_ACCOUNTED_DEAD,
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&memcg->kmem_account_flags);
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}
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#endif
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/* Stuffs for move charges at task migration. */
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/*
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* Types of charges to be moved. "move_charge_at_immitgrate" and
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* "immigrate_flags" are treated as a left-shifted bitmap of these types.
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*/
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enum move_type {
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MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */
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MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */
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NR_MOVE_TYPE,
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};
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/* "mc" and its members are protected by cgroup_mutex */
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static struct move_charge_struct {
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spinlock_t lock; /* for from, to */
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struct mem_cgroup *from;
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struct mem_cgroup *to;
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unsigned long immigrate_flags;
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unsigned long precharge;
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unsigned long moved_charge;
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unsigned long moved_swap;
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struct task_struct *moving_task; /* a task moving charges */
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wait_queue_head_t waitq; /* a waitq for other context */
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} mc = {
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.lock = __SPIN_LOCK_UNLOCKED(mc.lock),
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.waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
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};
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static bool move_anon(void)
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{
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return test_bit(MOVE_CHARGE_TYPE_ANON, &mc.immigrate_flags);
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}
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static bool move_file(void)
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{
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return test_bit(MOVE_CHARGE_TYPE_FILE, &mc.immigrate_flags);
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}
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/*
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* Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
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* limit reclaim to prevent infinite loops, if they ever occur.
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*/
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#define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
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#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
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enum charge_type {
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MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
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MEM_CGROUP_CHARGE_TYPE_ANON,
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MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
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MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
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NR_CHARGE_TYPE,
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};
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/* for encoding cft->private value on file */
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enum res_type {
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_MEM,
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_MEMSWAP,
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_OOM_TYPE,
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_KMEM,
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};
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#define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
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#define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
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#define MEMFILE_ATTR(val) ((val) & 0xffff)
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/* Used for OOM nofiier */
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#define OOM_CONTROL (0)
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/*
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* Reclaim flags for mem_cgroup_hierarchical_reclaim
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*/
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#define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
|
|
#define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
|
|
#define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
|
|
#define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
|
|
|
|
/*
|
|
* The memcg_create_mutex will be held whenever a new cgroup is created.
|
|
* As a consequence, any change that needs to protect against new child cgroups
|
|
* appearing has to hold it as well.
|
|
*/
|
|
static DEFINE_MUTEX(memcg_create_mutex);
|
|
|
|
struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s)
|
|
{
|
|
return s ? container_of(s, struct mem_cgroup, css) : NULL;
|
|
}
|
|
|
|
/* Some nice accessors for the vmpressure. */
|
|
struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg)
|
|
{
|
|
if (!memcg)
|
|
memcg = root_mem_cgroup;
|
|
return &memcg->vmpressure;
|
|
}
|
|
|
|
struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr)
|
|
{
|
|
return &container_of(vmpr, struct mem_cgroup, vmpressure)->css;
|
|
}
|
|
|
|
static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
|
|
{
|
|
return (memcg == root_mem_cgroup);
|
|
}
|
|
|
|
/*
|
|
* We restrict the id in the range of [1, 65535], so it can fit into
|
|
* an unsigned short.
|
|
*/
|
|
#define MEM_CGROUP_ID_MAX USHRT_MAX
|
|
|
|
static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
|
|
{
|
|
/*
|
|
* The ID of the root cgroup is 0, but memcg treat 0 as an
|
|
* invalid ID, so we return (cgroup_id + 1).
|
|
*/
|
|
return memcg->css.cgroup->id + 1;
|
|
}
|
|
|
|
static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
|
|
{
|
|
struct cgroup_subsys_state *css;
|
|
|
|
css = css_from_id(id - 1, &mem_cgroup_subsys);
|
|
return mem_cgroup_from_css(css);
|
|
}
|
|
|
|
/* Writing them here to avoid exposing memcg's inner layout */
|
|
#if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
|
|
|
|
void sock_update_memcg(struct sock *sk)
|
|
{
|
|
if (mem_cgroup_sockets_enabled) {
|
|
struct mem_cgroup *memcg;
|
|
struct cg_proto *cg_proto;
|
|
|
|
BUG_ON(!sk->sk_prot->proto_cgroup);
|
|
|
|
/* Socket cloning can throw us here with sk_cgrp already
|
|
* filled. It won't however, necessarily happen from
|
|
* process context. So the test for root memcg given
|
|
* the current task's memcg won't help us in this case.
|
|
*
|
|
* Respecting the original socket's memcg is a better
|
|
* decision in this case.
|
|
*/
|
|
if (sk->sk_cgrp) {
|
|
BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg));
|
|
css_get(&sk->sk_cgrp->memcg->css);
|
|
return;
|
|
}
|
|
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_from_task(current);
|
|
cg_proto = sk->sk_prot->proto_cgroup(memcg);
|
|
if (!mem_cgroup_is_root(memcg) &&
|
|
memcg_proto_active(cg_proto) && css_tryget(&memcg->css)) {
|
|
sk->sk_cgrp = cg_proto;
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(sock_update_memcg);
|
|
|
|
void sock_release_memcg(struct sock *sk)
|
|
{
|
|
if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
|
|
struct mem_cgroup *memcg;
|
|
WARN_ON(!sk->sk_cgrp->memcg);
|
|
memcg = sk->sk_cgrp->memcg;
|
|
css_put(&sk->sk_cgrp->memcg->css);
|
|
}
|
|
}
|
|
|
|
struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
|
|
{
|
|
if (!memcg || mem_cgroup_is_root(memcg))
|
|
return NULL;
|
|
|
|
return &memcg->tcp_mem;
|
|
}
|
|
EXPORT_SYMBOL(tcp_proto_cgroup);
|
|
|
|
static void disarm_sock_keys(struct mem_cgroup *memcg)
|
|
{
|
|
if (!memcg_proto_activated(&memcg->tcp_mem))
|
|
return;
|
|
static_key_slow_dec(&memcg_socket_limit_enabled);
|
|
}
|
|
#else
|
|
static void disarm_sock_keys(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
/*
|
|
* This will be the memcg's index in each cache's ->memcg_params->memcg_caches.
|
|
* The main reason for not using cgroup id for this:
|
|
* this works better in sparse environments, where we have a lot of memcgs,
|
|
* but only a few kmem-limited. Or also, if we have, for instance, 200
|
|
* memcgs, and none but the 200th is kmem-limited, we'd have to have a
|
|
* 200 entry array for that.
|
|
*
|
|
* The current size of the caches array is stored in
|
|
* memcg_limited_groups_array_size. It will double each time we have to
|
|
* increase it.
|
|
*/
|
|
static DEFINE_IDA(kmem_limited_groups);
|
|
int memcg_limited_groups_array_size;
|
|
|
|
/*
|
|
* MIN_SIZE is different than 1, because we would like to avoid going through
|
|
* the alloc/free process all the time. In a small machine, 4 kmem-limited
|
|
* cgroups is a reasonable guess. In the future, it could be a parameter or
|
|
* tunable, but that is strictly not necessary.
|
|
*
|
|
* MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
|
|
* this constant directly from cgroup, but it is understandable that this is
|
|
* better kept as an internal representation in cgroup.c. In any case, the
|
|
* cgrp_id space is not getting any smaller, and we don't have to necessarily
|
|
* increase ours as well if it increases.
|
|
*/
|
|
#define MEMCG_CACHES_MIN_SIZE 4
|
|
#define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
|
|
|
|
/*
|
|
* A lot of the calls to the cache allocation functions are expected to be
|
|
* inlined by the compiler. Since the calls to memcg_kmem_get_cache are
|
|
* conditional to this static branch, we'll have to allow modules that does
|
|
* kmem_cache_alloc and the such to see this symbol as well
|
|
*/
|
|
struct static_key memcg_kmem_enabled_key;
|
|
EXPORT_SYMBOL(memcg_kmem_enabled_key);
|
|
|
|
static void disarm_kmem_keys(struct mem_cgroup *memcg)
|
|
{
|
|
if (memcg_kmem_is_active(memcg)) {
|
|
static_key_slow_dec(&memcg_kmem_enabled_key);
|
|
ida_simple_remove(&kmem_limited_groups, memcg->kmemcg_id);
|
|
}
|
|
/*
|
|
* This check can't live in kmem destruction function,
|
|
* since the charges will outlive the cgroup
|
|
*/
|
|
WARN_ON(res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0);
|
|
}
|
|
#else
|
|
static void disarm_kmem_keys(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
#endif /* CONFIG_MEMCG_KMEM */
|
|
|
|
static void disarm_static_keys(struct mem_cgroup *memcg)
|
|
{
|
|
disarm_sock_keys(memcg);
|
|
disarm_kmem_keys(memcg);
|
|
}
|
|
|
|
static void drain_all_stock_async(struct mem_cgroup *memcg);
|
|
|
|
static struct mem_cgroup_per_zone *
|
|
mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid)
|
|
{
|
|
VM_BUG_ON((unsigned)nid >= nr_node_ids);
|
|
return &memcg->nodeinfo[nid]->zoneinfo[zid];
|
|
}
|
|
|
|
struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg)
|
|
{
|
|
return &memcg->css;
|
|
}
|
|
|
|
static struct mem_cgroup_per_zone *
|
|
page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page)
|
|
{
|
|
int nid = page_to_nid(page);
|
|
int zid = page_zonenum(page);
|
|
|
|
return mem_cgroup_zoneinfo(memcg, nid, zid);
|
|
}
|
|
|
|
static struct mem_cgroup_tree_per_zone *
|
|
soft_limit_tree_node_zone(int nid, int zid)
|
|
{
|
|
return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
|
|
}
|
|
|
|
static struct mem_cgroup_tree_per_zone *
|
|
soft_limit_tree_from_page(struct page *page)
|
|
{
|
|
int nid = page_to_nid(page);
|
|
int zid = page_zonenum(page);
|
|
|
|
return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
|
|
}
|
|
|
|
static void
|
|
__mem_cgroup_insert_exceeded(struct mem_cgroup *memcg,
|
|
struct mem_cgroup_per_zone *mz,
|
|
struct mem_cgroup_tree_per_zone *mctz,
|
|
unsigned long long new_usage_in_excess)
|
|
{
|
|
struct rb_node **p = &mctz->rb_root.rb_node;
|
|
struct rb_node *parent = NULL;
|
|
struct mem_cgroup_per_zone *mz_node;
|
|
|
|
if (mz->on_tree)
|
|
return;
|
|
|
|
mz->usage_in_excess = new_usage_in_excess;
|
|
if (!mz->usage_in_excess)
|
|
return;
|
|
while (*p) {
|
|
parent = *p;
|
|
mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
|
|
tree_node);
|
|
if (mz->usage_in_excess < mz_node->usage_in_excess)
|
|
p = &(*p)->rb_left;
|
|
/*
|
|
* We can't avoid mem cgroups that are over their soft
|
|
* limit by the same amount
|
|
*/
|
|
else if (mz->usage_in_excess >= mz_node->usage_in_excess)
|
|
p = &(*p)->rb_right;
|
|
}
|
|
rb_link_node(&mz->tree_node, parent, p);
|
|
rb_insert_color(&mz->tree_node, &mctz->rb_root);
|
|
mz->on_tree = true;
|
|
}
|
|
|
|
static void
|
|
__mem_cgroup_remove_exceeded(struct mem_cgroup *memcg,
|
|
struct mem_cgroup_per_zone *mz,
|
|
struct mem_cgroup_tree_per_zone *mctz)
|
|
{
|
|
if (!mz->on_tree)
|
|
return;
|
|
rb_erase(&mz->tree_node, &mctz->rb_root);
|
|
mz->on_tree = false;
|
|
}
|
|
|
|
static void
|
|
mem_cgroup_remove_exceeded(struct mem_cgroup *memcg,
|
|
struct mem_cgroup_per_zone *mz,
|
|
struct mem_cgroup_tree_per_zone *mctz)
|
|
{
|
|
spin_lock(&mctz->lock);
|
|
__mem_cgroup_remove_exceeded(memcg, mz, mctz);
|
|
spin_unlock(&mctz->lock);
|
|
}
|
|
|
|
|
|
static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page)
|
|
{
|
|
unsigned long long excess;
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct mem_cgroup_tree_per_zone *mctz;
|
|
int nid = page_to_nid(page);
|
|
int zid = page_zonenum(page);
|
|
mctz = soft_limit_tree_from_page(page);
|
|
|
|
/*
|
|
* Necessary to update all ancestors when hierarchy is used.
|
|
* because their event counter is not touched.
|
|
*/
|
|
for (; memcg; memcg = parent_mem_cgroup(memcg)) {
|
|
mz = mem_cgroup_zoneinfo(memcg, nid, zid);
|
|
excess = res_counter_soft_limit_excess(&memcg->res);
|
|
/*
|
|
* We have to update the tree if mz is on RB-tree or
|
|
* mem is over its softlimit.
|
|
*/
|
|
if (excess || mz->on_tree) {
|
|
spin_lock(&mctz->lock);
|
|
/* if on-tree, remove it */
|
|
if (mz->on_tree)
|
|
__mem_cgroup_remove_exceeded(memcg, mz, mctz);
|
|
/*
|
|
* Insert again. mz->usage_in_excess will be updated.
|
|
* If excess is 0, no tree ops.
|
|
*/
|
|
__mem_cgroup_insert_exceeded(memcg, mz, mctz, excess);
|
|
spin_unlock(&mctz->lock);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
|
|
{
|
|
int node, zone;
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct mem_cgroup_tree_per_zone *mctz;
|
|
|
|
for_each_node(node) {
|
|
for (zone = 0; zone < MAX_NR_ZONES; zone++) {
|
|
mz = mem_cgroup_zoneinfo(memcg, node, zone);
|
|
mctz = soft_limit_tree_node_zone(node, zone);
|
|
mem_cgroup_remove_exceeded(memcg, mz, mctz);
|
|
}
|
|
}
|
|
}
|
|
|
|
static struct mem_cgroup_per_zone *
|
|
__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
|
|
{
|
|
struct rb_node *rightmost = NULL;
|
|
struct mem_cgroup_per_zone *mz;
|
|
|
|
retry:
|
|
mz = NULL;
|
|
rightmost = rb_last(&mctz->rb_root);
|
|
if (!rightmost)
|
|
goto done; /* Nothing to reclaim from */
|
|
|
|
mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
|
|
/*
|
|
* Remove the node now but someone else can add it back,
|
|
* we will to add it back at the end of reclaim to its correct
|
|
* position in the tree.
|
|
*/
|
|
__mem_cgroup_remove_exceeded(mz->memcg, mz, mctz);
|
|
if (!res_counter_soft_limit_excess(&mz->memcg->res) ||
|
|
!css_tryget(&mz->memcg->css))
|
|
goto retry;
|
|
done:
|
|
return mz;
|
|
}
|
|
|
|
static struct mem_cgroup_per_zone *
|
|
mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
|
|
spin_lock(&mctz->lock);
|
|
mz = __mem_cgroup_largest_soft_limit_node(mctz);
|
|
spin_unlock(&mctz->lock);
|
|
return mz;
|
|
}
|
|
|
|
/*
|
|
* Implementation Note: reading percpu statistics for memcg.
|
|
*
|
|
* Both of vmstat[] and percpu_counter has threshold and do periodic
|
|
* synchronization to implement "quick" read. There are trade-off between
|
|
* reading cost and precision of value. Then, we may have a chance to implement
|
|
* a periodic synchronizion of counter in memcg's counter.
|
|
*
|
|
* But this _read() function is used for user interface now. The user accounts
|
|
* memory usage by memory cgroup and he _always_ requires exact value because
|
|
* he accounts memory. Even if we provide quick-and-fuzzy read, we always
|
|
* have to visit all online cpus and make sum. So, for now, unnecessary
|
|
* synchronization is not implemented. (just implemented for cpu hotplug)
|
|
*
|
|
* If there are kernel internal actions which can make use of some not-exact
|
|
* value, and reading all cpu value can be performance bottleneck in some
|
|
* common workload, threashold and synchonization as vmstat[] should be
|
|
* implemented.
|
|
*/
|
|
static long mem_cgroup_read_stat(struct mem_cgroup *memcg,
|
|
enum mem_cgroup_stat_index idx)
|
|
{
|
|
long val = 0;
|
|
int cpu;
|
|
|
|
get_online_cpus();
|
|
for_each_online_cpu(cpu)
|
|
val += per_cpu(memcg->stat->count[idx], cpu);
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
spin_lock(&memcg->pcp_counter_lock);
|
|
val += memcg->nocpu_base.count[idx];
|
|
spin_unlock(&memcg->pcp_counter_lock);
|
|
#endif
|
|
put_online_cpus();
|
|
return val;
|
|
}
|
|
|
|
static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,
|
|
bool charge)
|
|
{
|
|
int val = (charge) ? 1 : -1;
|
|
this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val);
|
|
}
|
|
|
|
static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg,
|
|
enum mem_cgroup_events_index idx)
|
|
{
|
|
unsigned long val = 0;
|
|
int cpu;
|
|
|
|
get_online_cpus();
|
|
for_each_online_cpu(cpu)
|
|
val += per_cpu(memcg->stat->events[idx], cpu);
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
spin_lock(&memcg->pcp_counter_lock);
|
|
val += memcg->nocpu_base.events[idx];
|
|
spin_unlock(&memcg->pcp_counter_lock);
|
|
#endif
|
|
put_online_cpus();
|
|
return val;
|
|
}
|
|
|
|
static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
|
|
struct page *page,
|
|
bool anon, int nr_pages)
|
|
{
|
|
preempt_disable();
|
|
|
|
/*
|
|
* Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
|
|
* counted as CACHE even if it's on ANON LRU.
|
|
*/
|
|
if (anon)
|
|
__this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS],
|
|
nr_pages);
|
|
else
|
|
__this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE],
|
|
nr_pages);
|
|
|
|
if (PageTransHuge(page))
|
|
__this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE],
|
|
nr_pages);
|
|
|
|
/* pagein of a big page is an event. So, ignore page size */
|
|
if (nr_pages > 0)
|
|
__this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]);
|
|
else {
|
|
__this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]);
|
|
nr_pages = -nr_pages; /* for event */
|
|
}
|
|
|
|
__this_cpu_add(memcg->stat->nr_page_events, nr_pages);
|
|
|
|
preempt_enable();
|
|
}
|
|
|
|
unsigned long
|
|
mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
|
|
mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
|
|
return mz->lru_size[lru];
|
|
}
|
|
|
|
static unsigned long
|
|
mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid,
|
|
unsigned int lru_mask)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
enum lru_list lru;
|
|
unsigned long ret = 0;
|
|
|
|
mz = mem_cgroup_zoneinfo(memcg, nid, zid);
|
|
|
|
for_each_lru(lru) {
|
|
if (BIT(lru) & lru_mask)
|
|
ret += mz->lru_size[lru];
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static unsigned long
|
|
mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
|
|
int nid, unsigned int lru_mask)
|
|
{
|
|
u64 total = 0;
|
|
int zid;
|
|
|
|
for (zid = 0; zid < MAX_NR_ZONES; zid++)
|
|
total += mem_cgroup_zone_nr_lru_pages(memcg,
|
|
nid, zid, lru_mask);
|
|
|
|
return total;
|
|
}
|
|
|
|
static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
|
|
unsigned int lru_mask)
|
|
{
|
|
int nid;
|
|
u64 total = 0;
|
|
|
|
for_each_node_state(nid, N_MEMORY)
|
|
total += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask);
|
|
return total;
|
|
}
|
|
|
|
static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
|
|
enum mem_cgroup_events_target target)
|
|
{
|
|
unsigned long val, next;
|
|
|
|
val = __this_cpu_read(memcg->stat->nr_page_events);
|
|
next = __this_cpu_read(memcg->stat->targets[target]);
|
|
/* from time_after() in jiffies.h */
|
|
if ((long)next - (long)val < 0) {
|
|
switch (target) {
|
|
case MEM_CGROUP_TARGET_THRESH:
|
|
next = val + THRESHOLDS_EVENTS_TARGET;
|
|
break;
|
|
case MEM_CGROUP_TARGET_SOFTLIMIT:
|
|
next = val + SOFTLIMIT_EVENTS_TARGET;
|
|
break;
|
|
case MEM_CGROUP_TARGET_NUMAINFO:
|
|
next = val + NUMAINFO_EVENTS_TARGET;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
__this_cpu_write(memcg->stat->targets[target], next);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Check events in order.
|
|
*
|
|
*/
|
|
static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
|
|
{
|
|
preempt_disable();
|
|
/* threshold event is triggered in finer grain than soft limit */
|
|
if (unlikely(mem_cgroup_event_ratelimit(memcg,
|
|
MEM_CGROUP_TARGET_THRESH))) {
|
|
bool do_softlimit;
|
|
bool do_numainfo __maybe_unused;
|
|
|
|
do_softlimit = mem_cgroup_event_ratelimit(memcg,
|
|
MEM_CGROUP_TARGET_SOFTLIMIT);
|
|
#if MAX_NUMNODES > 1
|
|
do_numainfo = mem_cgroup_event_ratelimit(memcg,
|
|
MEM_CGROUP_TARGET_NUMAINFO);
|
|
#endif
|
|
preempt_enable();
|
|
|
|
mem_cgroup_threshold(memcg);
|
|
if (unlikely(do_softlimit))
|
|
mem_cgroup_update_tree(memcg, page);
|
|
#if MAX_NUMNODES > 1
|
|
if (unlikely(do_numainfo))
|
|
atomic_inc(&memcg->numainfo_events);
|
|
#endif
|
|
} else
|
|
preempt_enable();
|
|
}
|
|
|
|
struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
|
|
{
|
|
/*
|
|
* mm_update_next_owner() may clear mm->owner to NULL
|
|
* if it races with swapoff, page migration, etc.
|
|
* So this can be called with p == NULL.
|
|
*/
|
|
if (unlikely(!p))
|
|
return NULL;
|
|
|
|
return mem_cgroup_from_css(task_css(p, mem_cgroup_subsys_id));
|
|
}
|
|
|
|
struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
|
|
if (!mm)
|
|
return NULL;
|
|
/*
|
|
* Because we have no locks, mm->owner's may be being moved to other
|
|
* cgroup. We use css_tryget() here even if this looks
|
|
* pessimistic (rather than adding locks here).
|
|
*/
|
|
rcu_read_lock();
|
|
do {
|
|
memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
|
|
if (unlikely(!memcg))
|
|
break;
|
|
} while (!css_tryget(&memcg->css));
|
|
rcu_read_unlock();
|
|
return memcg;
|
|
}
|
|
|
|
/*
|
|
* Returns a next (in a pre-order walk) alive memcg (with elevated css
|
|
* ref. count) or NULL if the whole root's subtree has been visited.
|
|
*
|
|
* helper function to be used by mem_cgroup_iter
|
|
*/
|
|
static struct mem_cgroup *__mem_cgroup_iter_next(struct mem_cgroup *root,
|
|
struct mem_cgroup *last_visited)
|
|
{
|
|
struct cgroup_subsys_state *prev_css, *next_css;
|
|
|
|
prev_css = last_visited ? &last_visited->css : NULL;
|
|
skip_node:
|
|
next_css = css_next_descendant_pre(prev_css, &root->css);
|
|
|
|
/*
|
|
* Even if we found a group we have to make sure it is
|
|
* alive. css && !memcg means that the groups should be
|
|
* skipped and we should continue the tree walk.
|
|
* last_visited css is safe to use because it is
|
|
* protected by css_get and the tree walk is rcu safe.
|
|
*
|
|
* We do not take a reference on the root of the tree walk
|
|
* because we might race with the root removal when it would
|
|
* be the only node in the iterated hierarchy and mem_cgroup_iter
|
|
* would end up in an endless loop because it expects that at
|
|
* least one valid node will be returned. Root cannot disappear
|
|
* because caller of the iterator should hold it already so
|
|
* skipping css reference should be safe.
|
|
*/
|
|
if (next_css) {
|
|
if ((next_css == &root->css) ||
|
|
((next_css->flags & CSS_ONLINE) && css_tryget(next_css)))
|
|
return mem_cgroup_from_css(next_css);
|
|
|
|
prev_css = next_css;
|
|
goto skip_node;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void mem_cgroup_iter_invalidate(struct mem_cgroup *root)
|
|
{
|
|
/*
|
|
* When a group in the hierarchy below root is destroyed, the
|
|
* hierarchy iterator can no longer be trusted since it might
|
|
* have pointed to the destroyed group. Invalidate it.
|
|
*/
|
|
atomic_inc(&root->dead_count);
|
|
}
|
|
|
|
static struct mem_cgroup *
|
|
mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter *iter,
|
|
struct mem_cgroup *root,
|
|
int *sequence)
|
|
{
|
|
struct mem_cgroup *position = NULL;
|
|
/*
|
|
* A cgroup destruction happens in two stages: offlining and
|
|
* release. They are separated by a RCU grace period.
|
|
*
|
|
* If the iterator is valid, we may still race with an
|
|
* offlining. The RCU lock ensures the object won't be
|
|
* released, tryget will fail if we lost the race.
|
|
*/
|
|
*sequence = atomic_read(&root->dead_count);
|
|
if (iter->last_dead_count == *sequence) {
|
|
smp_rmb();
|
|
position = iter->last_visited;
|
|
|
|
/*
|
|
* We cannot take a reference to root because we might race
|
|
* with root removal and returning NULL would end up in
|
|
* an endless loop on the iterator user level when root
|
|
* would be returned all the time.
|
|
*/
|
|
if (position && position != root &&
|
|
!css_tryget(&position->css))
|
|
position = NULL;
|
|
}
|
|
return position;
|
|
}
|
|
|
|
static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter *iter,
|
|
struct mem_cgroup *last_visited,
|
|
struct mem_cgroup *new_position,
|
|
struct mem_cgroup *root,
|
|
int sequence)
|
|
{
|
|
/* root reference counting symmetric to mem_cgroup_iter_load */
|
|
if (last_visited && last_visited != root)
|
|
css_put(&last_visited->css);
|
|
/*
|
|
* We store the sequence count from the time @last_visited was
|
|
* loaded successfully instead of rereading it here so that we
|
|
* don't lose destruction events in between. We could have
|
|
* raced with the destruction of @new_position after all.
|
|
*/
|
|
iter->last_visited = new_position;
|
|
smp_wmb();
|
|
iter->last_dead_count = sequence;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_iter - iterate over memory cgroup hierarchy
|
|
* @root: hierarchy root
|
|
* @prev: previously returned memcg, NULL on first invocation
|
|
* @reclaim: cookie for shared reclaim walks, NULL for full walks
|
|
*
|
|
* Returns references to children of the hierarchy below @root, or
|
|
* @root itself, or %NULL after a full round-trip.
|
|
*
|
|
* Caller must pass the return value in @prev on subsequent
|
|
* invocations for reference counting, or use mem_cgroup_iter_break()
|
|
* to cancel a hierarchy walk before the round-trip is complete.
|
|
*
|
|
* Reclaimers can specify a zone and a priority level in @reclaim to
|
|
* divide up the memcgs in the hierarchy among all concurrent
|
|
* reclaimers operating on the same zone and priority.
|
|
*/
|
|
struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
|
|
struct mem_cgroup *prev,
|
|
struct mem_cgroup_reclaim_cookie *reclaim)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
struct mem_cgroup *last_visited = NULL;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return NULL;
|
|
|
|
if (!root)
|
|
root = root_mem_cgroup;
|
|
|
|
if (prev && !reclaim)
|
|
last_visited = prev;
|
|
|
|
if (!root->use_hierarchy && root != root_mem_cgroup) {
|
|
if (prev)
|
|
goto out_css_put;
|
|
return root;
|
|
}
|
|
|
|
rcu_read_lock();
|
|
while (!memcg) {
|
|
struct mem_cgroup_reclaim_iter *uninitialized_var(iter);
|
|
int uninitialized_var(seq);
|
|
|
|
if (reclaim) {
|
|
int nid = zone_to_nid(reclaim->zone);
|
|
int zid = zone_idx(reclaim->zone);
|
|
struct mem_cgroup_per_zone *mz;
|
|
|
|
mz = mem_cgroup_zoneinfo(root, nid, zid);
|
|
iter = &mz->reclaim_iter[reclaim->priority];
|
|
if (prev && reclaim->generation != iter->generation) {
|
|
iter->last_visited = NULL;
|
|
goto out_unlock;
|
|
}
|
|
|
|
last_visited = mem_cgroup_iter_load(iter, root, &seq);
|
|
}
|
|
|
|
memcg = __mem_cgroup_iter_next(root, last_visited);
|
|
|
|
if (reclaim) {
|
|
mem_cgroup_iter_update(iter, last_visited, memcg, root,
|
|
seq);
|
|
|
|
if (!memcg)
|
|
iter->generation++;
|
|
else if (!prev && memcg)
|
|
reclaim->generation = iter->generation;
|
|
}
|
|
|
|
if (prev && !memcg)
|
|
goto out_unlock;
|
|
}
|
|
out_unlock:
|
|
rcu_read_unlock();
|
|
out_css_put:
|
|
if (prev && prev != root)
|
|
css_put(&prev->css);
|
|
|
|
return memcg;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_iter_break - abort a hierarchy walk prematurely
|
|
* @root: hierarchy root
|
|
* @prev: last visited hierarchy member as returned by mem_cgroup_iter()
|
|
*/
|
|
void mem_cgroup_iter_break(struct mem_cgroup *root,
|
|
struct mem_cgroup *prev)
|
|
{
|
|
if (!root)
|
|
root = root_mem_cgroup;
|
|
if (prev && prev != root)
|
|
css_put(&prev->css);
|
|
}
|
|
|
|
/*
|
|
* Iteration constructs for visiting all cgroups (under a tree). If
|
|
* loops are exited prematurely (break), mem_cgroup_iter_break() must
|
|
* be used for reference counting.
|
|
*/
|
|
#define for_each_mem_cgroup_tree(iter, root) \
|
|
for (iter = mem_cgroup_iter(root, NULL, NULL); \
|
|
iter != NULL; \
|
|
iter = mem_cgroup_iter(root, iter, NULL))
|
|
|
|
#define for_each_mem_cgroup(iter) \
|
|
for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
|
|
iter != NULL; \
|
|
iter = mem_cgroup_iter(NULL, iter, NULL))
|
|
|
|
void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
|
|
if (unlikely(!memcg))
|
|
goto out;
|
|
|
|
switch (idx) {
|
|
case PGFAULT:
|
|
this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]);
|
|
break;
|
|
case PGMAJFAULT:
|
|
this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]);
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
out:
|
|
rcu_read_unlock();
|
|
}
|
|
EXPORT_SYMBOL(__mem_cgroup_count_vm_event);
|
|
|
|
/**
|
|
* mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
|
|
* @zone: zone of the wanted lruvec
|
|
* @memcg: memcg of the wanted lruvec
|
|
*
|
|
* Returns the lru list vector holding pages for the given @zone and
|
|
* @mem. This can be the global zone lruvec, if the memory controller
|
|
* is disabled.
|
|
*/
|
|
struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
|
|
struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct lruvec *lruvec;
|
|
|
|
if (mem_cgroup_disabled()) {
|
|
lruvec = &zone->lruvec;
|
|
goto out;
|
|
}
|
|
|
|
mz = mem_cgroup_zoneinfo(memcg, zone_to_nid(zone), zone_idx(zone));
|
|
lruvec = &mz->lruvec;
|
|
out:
|
|
/*
|
|
* Since a node can be onlined after the mem_cgroup was created,
|
|
* we have to be prepared to initialize lruvec->zone here;
|
|
* and if offlined then reonlined, we need to reinitialize it.
|
|
*/
|
|
if (unlikely(lruvec->zone != zone))
|
|
lruvec->zone = zone;
|
|
return lruvec;
|
|
}
|
|
|
|
/*
|
|
* Following LRU functions are allowed to be used without PCG_LOCK.
|
|
* Operations are called by routine of global LRU independently from memcg.
|
|
* What we have to take care of here is validness of pc->mem_cgroup.
|
|
*
|
|
* Changes to pc->mem_cgroup happens when
|
|
* 1. charge
|
|
* 2. moving account
|
|
* In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
|
|
* It is added to LRU before charge.
|
|
* If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
|
|
* When moving account, the page is not on LRU. It's isolated.
|
|
*/
|
|
|
|
/**
|
|
* mem_cgroup_page_lruvec - return lruvec for adding an lru page
|
|
* @page: the page
|
|
* @zone: zone of the page
|
|
*/
|
|
struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct mem_cgroup *memcg;
|
|
struct page_cgroup *pc;
|
|
struct lruvec *lruvec;
|
|
|
|
if (mem_cgroup_disabled()) {
|
|
lruvec = &zone->lruvec;
|
|
goto out;
|
|
}
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
memcg = pc->mem_cgroup;
|
|
|
|
/*
|
|
* Surreptitiously switch any uncharged offlist page to root:
|
|
* an uncharged page off lru does nothing to secure
|
|
* its former mem_cgroup from sudden removal.
|
|
*
|
|
* Our caller holds lru_lock, and PageCgroupUsed is updated
|
|
* under page_cgroup lock: between them, they make all uses
|
|
* of pc->mem_cgroup safe.
|
|
*/
|
|
if (!PageLRU(page) && !PageCgroupUsed(pc) && memcg != root_mem_cgroup)
|
|
pc->mem_cgroup = memcg = root_mem_cgroup;
|
|
|
|
mz = page_cgroup_zoneinfo(memcg, page);
|
|
lruvec = &mz->lruvec;
|
|
out:
|
|
/*
|
|
* Since a node can be onlined after the mem_cgroup was created,
|
|
* we have to be prepared to initialize lruvec->zone here;
|
|
* and if offlined then reonlined, we need to reinitialize it.
|
|
*/
|
|
if (unlikely(lruvec->zone != zone))
|
|
lruvec->zone = zone;
|
|
return lruvec;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_update_lru_size - account for adding or removing an lru page
|
|
* @lruvec: mem_cgroup per zone lru vector
|
|
* @lru: index of lru list the page is sitting on
|
|
* @nr_pages: positive when adding or negative when removing
|
|
*
|
|
* This function must be called when a page is added to or removed from an
|
|
* lru list.
|
|
*/
|
|
void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
|
|
int nr_pages)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
unsigned long *lru_size;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
|
|
lru_size = mz->lru_size + lru;
|
|
*lru_size += nr_pages;
|
|
VM_BUG_ON((long)(*lru_size) < 0);
|
|
}
|
|
|
|
/*
|
|
* Checks whether given mem is same or in the root_mem_cgroup's
|
|
* hierarchy subtree
|
|
*/
|
|
bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
|
|
struct mem_cgroup *memcg)
|
|
{
|
|
if (root_memcg == memcg)
|
|
return true;
|
|
if (!root_memcg->use_hierarchy || !memcg)
|
|
return false;
|
|
return cgroup_is_descendant(memcg->css.cgroup, root_memcg->css.cgroup);
|
|
}
|
|
|
|
static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
|
|
struct mem_cgroup *memcg)
|
|
{
|
|
bool ret;
|
|
|
|
rcu_read_lock();
|
|
ret = __mem_cgroup_same_or_subtree(root_memcg, memcg);
|
|
rcu_read_unlock();
|
|
return ret;
|
|
}
|
|
|
|
bool task_in_mem_cgroup(struct task_struct *task,
|
|
const struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *curr = NULL;
|
|
struct task_struct *p;
|
|
bool ret;
|
|
|
|
p = find_lock_task_mm(task);
|
|
if (p) {
|
|
curr = try_get_mem_cgroup_from_mm(p->mm);
|
|
task_unlock(p);
|
|
} else {
|
|
/*
|
|
* All threads may have already detached their mm's, but the oom
|
|
* killer still needs to detect if they have already been oom
|
|
* killed to prevent needlessly killing additional tasks.
|
|
*/
|
|
rcu_read_lock();
|
|
curr = mem_cgroup_from_task(task);
|
|
if (curr)
|
|
css_get(&curr->css);
|
|
rcu_read_unlock();
|
|
}
|
|
if (!curr)
|
|
return false;
|
|
/*
|
|
* We should check use_hierarchy of "memcg" not "curr". Because checking
|
|
* use_hierarchy of "curr" here make this function true if hierarchy is
|
|
* enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
|
|
* hierarchy(even if use_hierarchy is disabled in "memcg").
|
|
*/
|
|
ret = mem_cgroup_same_or_subtree(memcg, curr);
|
|
css_put(&curr->css);
|
|
return ret;
|
|
}
|
|
|
|
int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
|
|
{
|
|
unsigned long inactive_ratio;
|
|
unsigned long inactive;
|
|
unsigned long active;
|
|
unsigned long gb;
|
|
|
|
inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON);
|
|
active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON);
|
|
|
|
gb = (inactive + active) >> (30 - PAGE_SHIFT);
|
|
if (gb)
|
|
inactive_ratio = int_sqrt(10 * gb);
|
|
else
|
|
inactive_ratio = 1;
|
|
|
|
return inactive * inactive_ratio < active;
|
|
}
|
|
|
|
#define mem_cgroup_from_res_counter(counter, member) \
|
|
container_of(counter, struct mem_cgroup, member)
|
|
|
|
/**
|
|
* mem_cgroup_margin - calculate chargeable space of a memory cgroup
|
|
* @memcg: the memory cgroup
|
|
*
|
|
* Returns the maximum amount of memory @mem can be charged with, in
|
|
* pages.
|
|
*/
|
|
static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg)
|
|
{
|
|
unsigned long long margin;
|
|
|
|
margin = res_counter_margin(&memcg->res);
|
|
if (do_swap_account)
|
|
margin = min(margin, res_counter_margin(&memcg->memsw));
|
|
return margin >> PAGE_SHIFT;
|
|
}
|
|
|
|
int mem_cgroup_swappiness(struct mem_cgroup *memcg)
|
|
{
|
|
/* root ? */
|
|
if (!css_parent(&memcg->css))
|
|
return vm_swappiness;
|
|
|
|
return memcg->swappiness;
|
|
}
|
|
|
|
/*
|
|
* memcg->moving_account is used for checking possibility that some thread is
|
|
* calling move_account(). When a thread on CPU-A starts moving pages under
|
|
* a memcg, other threads should check memcg->moving_account under
|
|
* rcu_read_lock(), like this:
|
|
*
|
|
* CPU-A CPU-B
|
|
* rcu_read_lock()
|
|
* memcg->moving_account+1 if (memcg->mocing_account)
|
|
* take heavy locks.
|
|
* synchronize_rcu() update something.
|
|
* rcu_read_unlock()
|
|
* start move here.
|
|
*/
|
|
|
|
/* for quick checking without looking up memcg */
|
|
atomic_t memcg_moving __read_mostly;
|
|
|
|
static void mem_cgroup_start_move(struct mem_cgroup *memcg)
|
|
{
|
|
atomic_inc(&memcg_moving);
|
|
atomic_inc(&memcg->moving_account);
|
|
synchronize_rcu();
|
|
}
|
|
|
|
static void mem_cgroup_end_move(struct mem_cgroup *memcg)
|
|
{
|
|
/*
|
|
* Now, mem_cgroup_clear_mc() may call this function with NULL.
|
|
* We check NULL in callee rather than caller.
|
|
*/
|
|
if (memcg) {
|
|
atomic_dec(&memcg_moving);
|
|
atomic_dec(&memcg->moving_account);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 2 routines for checking "mem" is under move_account() or not.
|
|
*
|
|
* mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This
|
|
* is used for avoiding races in accounting. If true,
|
|
* pc->mem_cgroup may be overwritten.
|
|
*
|
|
* mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
|
|
* under hierarchy of moving cgroups. This is for
|
|
* waiting at hith-memory prressure caused by "move".
|
|
*/
|
|
|
|
static bool mem_cgroup_stolen(struct mem_cgroup *memcg)
|
|
{
|
|
VM_BUG_ON(!rcu_read_lock_held());
|
|
return atomic_read(&memcg->moving_account) > 0;
|
|
}
|
|
|
|
static bool mem_cgroup_under_move(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *from;
|
|
struct mem_cgroup *to;
|
|
bool ret = false;
|
|
/*
|
|
* Unlike task_move routines, we access mc.to, mc.from not under
|
|
* mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
|
|
*/
|
|
spin_lock(&mc.lock);
|
|
from = mc.from;
|
|
to = mc.to;
|
|
if (!from)
|
|
goto unlock;
|
|
|
|
ret = mem_cgroup_same_or_subtree(memcg, from)
|
|
|| mem_cgroup_same_or_subtree(memcg, to);
|
|
unlock:
|
|
spin_unlock(&mc.lock);
|
|
return ret;
|
|
}
|
|
|
|
static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg)
|
|
{
|
|
if (mc.moving_task && current != mc.moving_task) {
|
|
if (mem_cgroup_under_move(memcg)) {
|
|
DEFINE_WAIT(wait);
|
|
prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
|
|
/* moving charge context might have finished. */
|
|
if (mc.moving_task)
|
|
schedule();
|
|
finish_wait(&mc.waitq, &wait);
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Take this lock when
|
|
* - a code tries to modify page's memcg while it's USED.
|
|
* - a code tries to modify page state accounting in a memcg.
|
|
* see mem_cgroup_stolen(), too.
|
|
*/
|
|
static void move_lock_mem_cgroup(struct mem_cgroup *memcg,
|
|
unsigned long *flags)
|
|
{
|
|
spin_lock_irqsave(&memcg->move_lock, *flags);
|
|
}
|
|
|
|
static void move_unlock_mem_cgroup(struct mem_cgroup *memcg,
|
|
unsigned long *flags)
|
|
{
|
|
spin_unlock_irqrestore(&memcg->move_lock, *flags);
|
|
}
|
|
|
|
#define K(x) ((x) << (PAGE_SHIFT-10))
|
|
/**
|
|
* mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
|
|
* @memcg: The memory cgroup that went over limit
|
|
* @p: Task that is going to be killed
|
|
*
|
|
* NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
|
|
* enabled
|
|
*/
|
|
void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
|
|
{
|
|
/*
|
|
* protects memcg_name and makes sure that parallel ooms do not
|
|
* interleave
|
|
*/
|
|
static DEFINE_MUTEX(oom_info_lock);
|
|
struct cgroup *task_cgrp;
|
|
struct cgroup *mem_cgrp;
|
|
static char memcg_name[PATH_MAX];
|
|
int ret;
|
|
struct mem_cgroup *iter;
|
|
unsigned int i;
|
|
|
|
if (!p)
|
|
return;
|
|
|
|
mutex_lock(&oom_info_lock);
|
|
rcu_read_lock();
|
|
|
|
mem_cgrp = memcg->css.cgroup;
|
|
task_cgrp = task_cgroup(p, mem_cgroup_subsys_id);
|
|
|
|
ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX);
|
|
if (ret < 0) {
|
|
/*
|
|
* Unfortunately, we are unable to convert to a useful name
|
|
* But we'll still print out the usage information
|
|
*/
|
|
rcu_read_unlock();
|
|
goto done;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
pr_info("Task in %s killed", memcg_name);
|
|
|
|
rcu_read_lock();
|
|
ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX);
|
|
if (ret < 0) {
|
|
rcu_read_unlock();
|
|
goto done;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
/*
|
|
* Continues from above, so we don't need an KERN_ level
|
|
*/
|
|
pr_cont(" as a result of limit of %s\n", memcg_name);
|
|
done:
|
|
|
|
pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n",
|
|
res_counter_read_u64(&memcg->res, RES_USAGE) >> 10,
|
|
res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10,
|
|
res_counter_read_u64(&memcg->res, RES_FAILCNT));
|
|
pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n",
|
|
res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
|
|
res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
|
|
res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
|
|
pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n",
|
|
res_counter_read_u64(&memcg->kmem, RES_USAGE) >> 10,
|
|
res_counter_read_u64(&memcg->kmem, RES_LIMIT) >> 10,
|
|
res_counter_read_u64(&memcg->kmem, RES_FAILCNT));
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg) {
|
|
pr_info("Memory cgroup stats");
|
|
|
|
rcu_read_lock();
|
|
ret = cgroup_path(iter->css.cgroup, memcg_name, PATH_MAX);
|
|
if (!ret)
|
|
pr_cont(" for %s", memcg_name);
|
|
rcu_read_unlock();
|
|
pr_cont(":");
|
|
|
|
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
|
|
if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
|
|
continue;
|
|
pr_cont(" %s:%ldKB", mem_cgroup_stat_names[i],
|
|
K(mem_cgroup_read_stat(iter, i)));
|
|
}
|
|
|
|
for (i = 0; i < NR_LRU_LISTS; i++)
|
|
pr_cont(" %s:%luKB", mem_cgroup_lru_names[i],
|
|
K(mem_cgroup_nr_lru_pages(iter, BIT(i))));
|
|
|
|
pr_cont("\n");
|
|
}
|
|
mutex_unlock(&oom_info_lock);
|
|
}
|
|
|
|
/*
|
|
* This function returns the number of memcg under hierarchy tree. Returns
|
|
* 1(self count) if no children.
|
|
*/
|
|
static int mem_cgroup_count_children(struct mem_cgroup *memcg)
|
|
{
|
|
int num = 0;
|
|
struct mem_cgroup *iter;
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
num++;
|
|
return num;
|
|
}
|
|
|
|
/*
|
|
* Return the memory (and swap, if configured) limit for a memcg.
|
|
*/
|
|
static u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
|
|
{
|
|
u64 limit;
|
|
|
|
limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
|
|
|
|
/*
|
|
* Do not consider swap space if we cannot swap due to swappiness
|
|
*/
|
|
if (mem_cgroup_swappiness(memcg)) {
|
|
u64 memsw;
|
|
|
|
limit += total_swap_pages << PAGE_SHIFT;
|
|
memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
|
|
|
|
/*
|
|
* If memsw is finite and limits the amount of swap space
|
|
* available to this memcg, return that limit.
|
|
*/
|
|
limit = min(limit, memsw);
|
|
}
|
|
|
|
return limit;
|
|
}
|
|
|
|
static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
|
|
int order)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
unsigned long chosen_points = 0;
|
|
unsigned long totalpages;
|
|
unsigned int points = 0;
|
|
struct task_struct *chosen = NULL;
|
|
|
|
/*
|
|
* If current has a pending SIGKILL or is exiting, then automatically
|
|
* select it. The goal is to allow it to allocate so that it may
|
|
* quickly exit and free its memory.
|
|
*/
|
|
if (fatal_signal_pending(current) || current->flags & PF_EXITING) {
|
|
set_thread_flag(TIF_MEMDIE);
|
|
return;
|
|
}
|
|
|
|
check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL);
|
|
totalpages = mem_cgroup_get_limit(memcg) >> PAGE_SHIFT ? : 1;
|
|
for_each_mem_cgroup_tree(iter, memcg) {
|
|
struct css_task_iter it;
|
|
struct task_struct *task;
|
|
|
|
css_task_iter_start(&iter->css, &it);
|
|
while ((task = css_task_iter_next(&it))) {
|
|
switch (oom_scan_process_thread(task, totalpages, NULL,
|
|
false)) {
|
|
case OOM_SCAN_SELECT:
|
|
if (chosen)
|
|
put_task_struct(chosen);
|
|
chosen = task;
|
|
chosen_points = ULONG_MAX;
|
|
get_task_struct(chosen);
|
|
/* fall through */
|
|
case OOM_SCAN_CONTINUE:
|
|
continue;
|
|
case OOM_SCAN_ABORT:
|
|
css_task_iter_end(&it);
|
|
mem_cgroup_iter_break(memcg, iter);
|
|
if (chosen)
|
|
put_task_struct(chosen);
|
|
return;
|
|
case OOM_SCAN_OK:
|
|
break;
|
|
};
|
|
points = oom_badness(task, memcg, NULL, totalpages);
|
|
if (!points || points < chosen_points)
|
|
continue;
|
|
/* Prefer thread group leaders for display purposes */
|
|
if (points == chosen_points &&
|
|
thread_group_leader(chosen))
|
|
continue;
|
|
|
|
if (chosen)
|
|
put_task_struct(chosen);
|
|
chosen = task;
|
|
chosen_points = points;
|
|
get_task_struct(chosen);
|
|
}
|
|
css_task_iter_end(&it);
|
|
}
|
|
|
|
if (!chosen)
|
|
return;
|
|
points = chosen_points * 1000 / totalpages;
|
|
oom_kill_process(chosen, gfp_mask, order, points, totalpages, memcg,
|
|
NULL, "Memory cgroup out of memory");
|
|
}
|
|
|
|
static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg,
|
|
gfp_t gfp_mask,
|
|
unsigned long flags)
|
|
{
|
|
unsigned long total = 0;
|
|
bool noswap = false;
|
|
int loop;
|
|
|
|
if (flags & MEM_CGROUP_RECLAIM_NOSWAP)
|
|
noswap = true;
|
|
if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum)
|
|
noswap = true;
|
|
|
|
for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) {
|
|
if (loop)
|
|
drain_all_stock_async(memcg);
|
|
total += try_to_free_mem_cgroup_pages(memcg, gfp_mask, noswap);
|
|
/*
|
|
* Allow limit shrinkers, which are triggered directly
|
|
* by userspace, to catch signals and stop reclaim
|
|
* after minimal progress, regardless of the margin.
|
|
*/
|
|
if (total && (flags & MEM_CGROUP_RECLAIM_SHRINK))
|
|
break;
|
|
if (mem_cgroup_margin(memcg))
|
|
break;
|
|
/*
|
|
* If nothing was reclaimed after two attempts, there
|
|
* may be no reclaimable pages in this hierarchy.
|
|
*/
|
|
if (loop && !total)
|
|
break;
|
|
}
|
|
return total;
|
|
}
|
|
|
|
/**
|
|
* test_mem_cgroup_node_reclaimable
|
|
* @memcg: the target memcg
|
|
* @nid: the node ID to be checked.
|
|
* @noswap : specify true here if the user wants flle only information.
|
|
*
|
|
* This function returns whether the specified memcg contains any
|
|
* reclaimable pages on a node. Returns true if there are any reclaimable
|
|
* pages in the node.
|
|
*/
|
|
static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg,
|
|
int nid, bool noswap)
|
|
{
|
|
if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE))
|
|
return true;
|
|
if (noswap || !total_swap_pages)
|
|
return false;
|
|
if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON))
|
|
return true;
|
|
return false;
|
|
|
|
}
|
|
#if MAX_NUMNODES > 1
|
|
|
|
/*
|
|
* Always updating the nodemask is not very good - even if we have an empty
|
|
* list or the wrong list here, we can start from some node and traverse all
|
|
* nodes based on the zonelist. So update the list loosely once per 10 secs.
|
|
*
|
|
*/
|
|
static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg)
|
|
{
|
|
int nid;
|
|
/*
|
|
* numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
|
|
* pagein/pageout changes since the last update.
|
|
*/
|
|
if (!atomic_read(&memcg->numainfo_events))
|
|
return;
|
|
if (atomic_inc_return(&memcg->numainfo_updating) > 1)
|
|
return;
|
|
|
|
/* make a nodemask where this memcg uses memory from */
|
|
memcg->scan_nodes = node_states[N_MEMORY];
|
|
|
|
for_each_node_mask(nid, node_states[N_MEMORY]) {
|
|
|
|
if (!test_mem_cgroup_node_reclaimable(memcg, nid, false))
|
|
node_clear(nid, memcg->scan_nodes);
|
|
}
|
|
|
|
atomic_set(&memcg->numainfo_events, 0);
|
|
atomic_set(&memcg->numainfo_updating, 0);
|
|
}
|
|
|
|
/*
|
|
* Selecting a node where we start reclaim from. Because what we need is just
|
|
* reducing usage counter, start from anywhere is O,K. Considering
|
|
* memory reclaim from current node, there are pros. and cons.
|
|
*
|
|
* Freeing memory from current node means freeing memory from a node which
|
|
* we'll use or we've used. So, it may make LRU bad. And if several threads
|
|
* hit limits, it will see a contention on a node. But freeing from remote
|
|
* node means more costs for memory reclaim because of memory latency.
|
|
*
|
|
* Now, we use round-robin. Better algorithm is welcomed.
|
|
*/
|
|
int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
|
|
{
|
|
int node;
|
|
|
|
mem_cgroup_may_update_nodemask(memcg);
|
|
node = memcg->last_scanned_node;
|
|
|
|
node = next_node(node, memcg->scan_nodes);
|
|
if (node == MAX_NUMNODES)
|
|
node = first_node(memcg->scan_nodes);
|
|
/*
|
|
* We call this when we hit limit, not when pages are added to LRU.
|
|
* No LRU may hold pages because all pages are UNEVICTABLE or
|
|
* memcg is too small and all pages are not on LRU. In that case,
|
|
* we use curret node.
|
|
*/
|
|
if (unlikely(node == MAX_NUMNODES))
|
|
node = numa_node_id();
|
|
|
|
memcg->last_scanned_node = node;
|
|
return node;
|
|
}
|
|
|
|
/*
|
|
* Check all nodes whether it contains reclaimable pages or not.
|
|
* For quick scan, we make use of scan_nodes. This will allow us to skip
|
|
* unused nodes. But scan_nodes is lazily updated and may not cotain
|
|
* enough new information. We need to do double check.
|
|
*/
|
|
static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap)
|
|
{
|
|
int nid;
|
|
|
|
/*
|
|
* quick check...making use of scan_node.
|
|
* We can skip unused nodes.
|
|
*/
|
|
if (!nodes_empty(memcg->scan_nodes)) {
|
|
for (nid = first_node(memcg->scan_nodes);
|
|
nid < MAX_NUMNODES;
|
|
nid = next_node(nid, memcg->scan_nodes)) {
|
|
|
|
if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap))
|
|
return true;
|
|
}
|
|
}
|
|
/*
|
|
* Check rest of nodes.
|
|
*/
|
|
for_each_node_state(nid, N_MEMORY) {
|
|
if (node_isset(nid, memcg->scan_nodes))
|
|
continue;
|
|
if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap))
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
#else
|
|
int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap)
|
|
{
|
|
return test_mem_cgroup_node_reclaimable(memcg, 0, noswap);
|
|
}
|
|
#endif
|
|
|
|
static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
|
|
struct zone *zone,
|
|
gfp_t gfp_mask,
|
|
unsigned long *total_scanned)
|
|
{
|
|
struct mem_cgroup *victim = NULL;
|
|
int total = 0;
|
|
int loop = 0;
|
|
unsigned long excess;
|
|
unsigned long nr_scanned;
|
|
struct mem_cgroup_reclaim_cookie reclaim = {
|
|
.zone = zone,
|
|
.priority = 0,
|
|
};
|
|
|
|
excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT;
|
|
|
|
while (1) {
|
|
victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
|
|
if (!victim) {
|
|
loop++;
|
|
if (loop >= 2) {
|
|
/*
|
|
* If we have not been able to reclaim
|
|
* anything, it might because there are
|
|
* no reclaimable pages under this hierarchy
|
|
*/
|
|
if (!total)
|
|
break;
|
|
/*
|
|
* We want to do more targeted reclaim.
|
|
* excess >> 2 is not to excessive so as to
|
|
* reclaim too much, nor too less that we keep
|
|
* coming back to reclaim from this cgroup
|
|
*/
|
|
if (total >= (excess >> 2) ||
|
|
(loop > MEM_CGROUP_MAX_RECLAIM_LOOPS))
|
|
break;
|
|
}
|
|
continue;
|
|
}
|
|
if (!mem_cgroup_reclaimable(victim, false))
|
|
continue;
|
|
total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false,
|
|
zone, &nr_scanned);
|
|
*total_scanned += nr_scanned;
|
|
if (!res_counter_soft_limit_excess(&root_memcg->res))
|
|
break;
|
|
}
|
|
mem_cgroup_iter_break(root_memcg, victim);
|
|
return total;
|
|
}
|
|
|
|
#ifdef CONFIG_LOCKDEP
|
|
static struct lockdep_map memcg_oom_lock_dep_map = {
|
|
.name = "memcg_oom_lock",
|
|
};
|
|
#endif
|
|
|
|
static DEFINE_SPINLOCK(memcg_oom_lock);
|
|
|
|
/*
|
|
* Check OOM-Killer is already running under our hierarchy.
|
|
* If someone is running, return false.
|
|
*/
|
|
static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter, *failed = NULL;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg) {
|
|
if (iter->oom_lock) {
|
|
/*
|
|
* this subtree of our hierarchy is already locked
|
|
* so we cannot give a lock.
|
|
*/
|
|
failed = iter;
|
|
mem_cgroup_iter_break(memcg, iter);
|
|
break;
|
|
} else
|
|
iter->oom_lock = true;
|
|
}
|
|
|
|
if (failed) {
|
|
/*
|
|
* OK, we failed to lock the whole subtree so we have
|
|
* to clean up what we set up to the failing subtree
|
|
*/
|
|
for_each_mem_cgroup_tree(iter, memcg) {
|
|
if (iter == failed) {
|
|
mem_cgroup_iter_break(memcg, iter);
|
|
break;
|
|
}
|
|
iter->oom_lock = false;
|
|
}
|
|
} else
|
|
mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_);
|
|
|
|
spin_unlock(&memcg_oom_lock);
|
|
|
|
return !failed;
|
|
}
|
|
|
|
static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
mutex_release(&memcg_oom_lock_dep_map, 1, _RET_IP_);
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
iter->oom_lock = false;
|
|
spin_unlock(&memcg_oom_lock);
|
|
}
|
|
|
|
static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
atomic_inc(&iter->under_oom);
|
|
}
|
|
|
|
static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
/*
|
|
* When a new child is created while the hierarchy is under oom,
|
|
* mem_cgroup_oom_lock() may not be called. We have to use
|
|
* atomic_add_unless() here.
|
|
*/
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
atomic_add_unless(&iter->under_oom, -1, 0);
|
|
}
|
|
|
|
static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
|
|
|
|
struct oom_wait_info {
|
|
struct mem_cgroup *memcg;
|
|
wait_queue_t wait;
|
|
};
|
|
|
|
static int memcg_oom_wake_function(wait_queue_t *wait,
|
|
unsigned mode, int sync, void *arg)
|
|
{
|
|
struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg;
|
|
struct mem_cgroup *oom_wait_memcg;
|
|
struct oom_wait_info *oom_wait_info;
|
|
|
|
oom_wait_info = container_of(wait, struct oom_wait_info, wait);
|
|
oom_wait_memcg = oom_wait_info->memcg;
|
|
|
|
/*
|
|
* Both of oom_wait_info->memcg and wake_memcg are stable under us.
|
|
* Then we can use css_is_ancestor without taking care of RCU.
|
|
*/
|
|
if (!mem_cgroup_same_or_subtree(oom_wait_memcg, wake_memcg)
|
|
&& !mem_cgroup_same_or_subtree(wake_memcg, oom_wait_memcg))
|
|
return 0;
|
|
return autoremove_wake_function(wait, mode, sync, arg);
|
|
}
|
|
|
|
static void memcg_wakeup_oom(struct mem_cgroup *memcg)
|
|
{
|
|
atomic_inc(&memcg->oom_wakeups);
|
|
/* for filtering, pass "memcg" as argument. */
|
|
__wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg);
|
|
}
|
|
|
|
static void memcg_oom_recover(struct mem_cgroup *memcg)
|
|
{
|
|
if (memcg && atomic_read(&memcg->under_oom))
|
|
memcg_wakeup_oom(memcg);
|
|
}
|
|
|
|
static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order)
|
|
{
|
|
if (!current->memcg_oom.may_oom)
|
|
return;
|
|
/*
|
|
* We are in the middle of the charge context here, so we
|
|
* don't want to block when potentially sitting on a callstack
|
|
* that holds all kinds of filesystem and mm locks.
|
|
*
|
|
* Also, the caller may handle a failed allocation gracefully
|
|
* (like optional page cache readahead) and so an OOM killer
|
|
* invocation might not even be necessary.
|
|
*
|
|
* That's why we don't do anything here except remember the
|
|
* OOM context and then deal with it at the end of the page
|
|
* fault when the stack is unwound, the locks are released,
|
|
* and when we know whether the fault was overall successful.
|
|
*/
|
|
css_get(&memcg->css);
|
|
current->memcg_oom.memcg = memcg;
|
|
current->memcg_oom.gfp_mask = mask;
|
|
current->memcg_oom.order = order;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_oom_synchronize - complete memcg OOM handling
|
|
* @handle: actually kill/wait or just clean up the OOM state
|
|
*
|
|
* This has to be called at the end of a page fault if the memcg OOM
|
|
* handler was enabled.
|
|
*
|
|
* Memcg supports userspace OOM handling where failed allocations must
|
|
* sleep on a waitqueue until the userspace task resolves the
|
|
* situation. Sleeping directly in the charge context with all kinds
|
|
* of locks held is not a good idea, instead we remember an OOM state
|
|
* in the task and mem_cgroup_oom_synchronize() has to be called at
|
|
* the end of the page fault to complete the OOM handling.
|
|
*
|
|
* Returns %true if an ongoing memcg OOM situation was detected and
|
|
* completed, %false otherwise.
|
|
*/
|
|
bool mem_cgroup_oom_synchronize(bool handle)
|
|
{
|
|
struct mem_cgroup *memcg = current->memcg_oom.memcg;
|
|
struct oom_wait_info owait;
|
|
bool locked;
|
|
|
|
/* OOM is global, do not handle */
|
|
if (!memcg)
|
|
return false;
|
|
|
|
if (!handle)
|
|
goto cleanup;
|
|
|
|
owait.memcg = memcg;
|
|
owait.wait.flags = 0;
|
|
owait.wait.func = memcg_oom_wake_function;
|
|
owait.wait.private = current;
|
|
INIT_LIST_HEAD(&owait.wait.task_list);
|
|
|
|
prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
|
|
mem_cgroup_mark_under_oom(memcg);
|
|
|
|
locked = mem_cgroup_oom_trylock(memcg);
|
|
|
|
if (locked)
|
|
mem_cgroup_oom_notify(memcg);
|
|
|
|
if (locked && !memcg->oom_kill_disable) {
|
|
mem_cgroup_unmark_under_oom(memcg);
|
|
finish_wait(&memcg_oom_waitq, &owait.wait);
|
|
mem_cgroup_out_of_memory(memcg, current->memcg_oom.gfp_mask,
|
|
current->memcg_oom.order);
|
|
} else {
|
|
schedule();
|
|
mem_cgroup_unmark_under_oom(memcg);
|
|
finish_wait(&memcg_oom_waitq, &owait.wait);
|
|
}
|
|
|
|
if (locked) {
|
|
mem_cgroup_oom_unlock(memcg);
|
|
/*
|
|
* There is no guarantee that an OOM-lock contender
|
|
* sees the wakeups triggered by the OOM kill
|
|
* uncharges. Wake any sleepers explicitely.
|
|
*/
|
|
memcg_oom_recover(memcg);
|
|
}
|
|
cleanup:
|
|
current->memcg_oom.memcg = NULL;
|
|
css_put(&memcg->css);
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Currently used to update mapped file statistics, but the routine can be
|
|
* generalized to update other statistics as well.
|
|
*
|
|
* Notes: Race condition
|
|
*
|
|
* We usually use page_cgroup_lock() for accessing page_cgroup member but
|
|
* it tends to be costly. But considering some conditions, we doesn't need
|
|
* to do so _always_.
|
|
*
|
|
* Considering "charge", lock_page_cgroup() is not required because all
|
|
* file-stat operations happen after a page is attached to radix-tree. There
|
|
* are no race with "charge".
|
|
*
|
|
* Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
|
|
* at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
|
|
* if there are race with "uncharge". Statistics itself is properly handled
|
|
* by flags.
|
|
*
|
|
* Considering "move", this is an only case we see a race. To make the race
|
|
* small, we check mm->moving_account and detect there are possibility of race
|
|
* If there is, we take a lock.
|
|
*/
|
|
|
|
void __mem_cgroup_begin_update_page_stat(struct page *page,
|
|
bool *locked, unsigned long *flags)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
struct page_cgroup *pc;
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
again:
|
|
memcg = pc->mem_cgroup;
|
|
if (unlikely(!memcg || !PageCgroupUsed(pc)))
|
|
return;
|
|
/*
|
|
* If this memory cgroup is not under account moving, we don't
|
|
* need to take move_lock_mem_cgroup(). Because we already hold
|
|
* rcu_read_lock(), any calls to move_account will be delayed until
|
|
* rcu_read_unlock() if mem_cgroup_stolen() == true.
|
|
*/
|
|
if (!mem_cgroup_stolen(memcg))
|
|
return;
|
|
|
|
move_lock_mem_cgroup(memcg, flags);
|
|
if (memcg != pc->mem_cgroup || !PageCgroupUsed(pc)) {
|
|
move_unlock_mem_cgroup(memcg, flags);
|
|
goto again;
|
|
}
|
|
*locked = true;
|
|
}
|
|
|
|
void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags)
|
|
{
|
|
struct page_cgroup *pc = lookup_page_cgroup(page);
|
|
|
|
/*
|
|
* It's guaranteed that pc->mem_cgroup never changes while
|
|
* lock is held because a routine modifies pc->mem_cgroup
|
|
* should take move_lock_mem_cgroup().
|
|
*/
|
|
move_unlock_mem_cgroup(pc->mem_cgroup, flags);
|
|
}
|
|
|
|
void mem_cgroup_update_page_stat(struct page *page,
|
|
enum mem_cgroup_stat_index idx, int val)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
struct page_cgroup *pc = lookup_page_cgroup(page);
|
|
unsigned long uninitialized_var(flags);
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
VM_BUG_ON(!rcu_read_lock_held());
|
|
memcg = pc->mem_cgroup;
|
|
if (unlikely(!memcg || !PageCgroupUsed(pc)))
|
|
return;
|
|
|
|
this_cpu_add(memcg->stat->count[idx], val);
|
|
}
|
|
|
|
/*
|
|
* size of first charge trial. "32" comes from vmscan.c's magic value.
|
|
* TODO: maybe necessary to use big numbers in big irons.
|
|
*/
|
|
#define CHARGE_BATCH 32U
|
|
struct memcg_stock_pcp {
|
|
struct mem_cgroup *cached; /* this never be root cgroup */
|
|
unsigned int nr_pages;
|
|
struct work_struct work;
|
|
unsigned long flags;
|
|
#define FLUSHING_CACHED_CHARGE 0
|
|
};
|
|
static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
|
|
static DEFINE_MUTEX(percpu_charge_mutex);
|
|
|
|
/**
|
|
* consume_stock: Try to consume stocked charge on this cpu.
|
|
* @memcg: memcg to consume from.
|
|
* @nr_pages: how many pages to charge.
|
|
*
|
|
* The charges will only happen if @memcg matches the current cpu's memcg
|
|
* stock, and at least @nr_pages are available in that stock. Failure to
|
|
* service an allocation will refill the stock.
|
|
*
|
|
* returns true if successful, false otherwise.
|
|
*/
|
|
static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
|
|
{
|
|
struct memcg_stock_pcp *stock;
|
|
bool ret = true;
|
|
|
|
if (nr_pages > CHARGE_BATCH)
|
|
return false;
|
|
|
|
stock = &get_cpu_var(memcg_stock);
|
|
if (memcg == stock->cached && stock->nr_pages >= nr_pages)
|
|
stock->nr_pages -= nr_pages;
|
|
else /* need to call res_counter_charge */
|
|
ret = false;
|
|
put_cpu_var(memcg_stock);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Returns stocks cached in percpu to res_counter and reset cached information.
|
|
*/
|
|
static void drain_stock(struct memcg_stock_pcp *stock)
|
|
{
|
|
struct mem_cgroup *old = stock->cached;
|
|
|
|
if (stock->nr_pages) {
|
|
unsigned long bytes = stock->nr_pages * PAGE_SIZE;
|
|
|
|
res_counter_uncharge(&old->res, bytes);
|
|
if (do_swap_account)
|
|
res_counter_uncharge(&old->memsw, bytes);
|
|
stock->nr_pages = 0;
|
|
}
|
|
stock->cached = NULL;
|
|
}
|
|
|
|
/*
|
|
* This must be called under preempt disabled or must be called by
|
|
* a thread which is pinned to local cpu.
|
|
*/
|
|
static void drain_local_stock(struct work_struct *dummy)
|
|
{
|
|
struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock);
|
|
drain_stock(stock);
|
|
clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
|
|
}
|
|
|
|
static void __init memcg_stock_init(void)
|
|
{
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
struct memcg_stock_pcp *stock =
|
|
&per_cpu(memcg_stock, cpu);
|
|
INIT_WORK(&stock->work, drain_local_stock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Cache charges(val) which is from res_counter, to local per_cpu area.
|
|
* This will be consumed by consume_stock() function, later.
|
|
*/
|
|
static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
|
|
{
|
|
struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
|
|
|
|
if (stock->cached != memcg) { /* reset if necessary */
|
|
drain_stock(stock);
|
|
stock->cached = memcg;
|
|
}
|
|
stock->nr_pages += nr_pages;
|
|
put_cpu_var(memcg_stock);
|
|
}
|
|
|
|
/*
|
|
* Drains all per-CPU charge caches for given root_memcg resp. subtree
|
|
* of the hierarchy under it. sync flag says whether we should block
|
|
* until the work is done.
|
|
*/
|
|
static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync)
|
|
{
|
|
int cpu, curcpu;
|
|
|
|
/* Notify other cpus that system-wide "drain" is running */
|
|
get_online_cpus();
|
|
curcpu = get_cpu();
|
|
for_each_online_cpu(cpu) {
|
|
struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
|
|
struct mem_cgroup *memcg;
|
|
|
|
memcg = stock->cached;
|
|
if (!memcg || !stock->nr_pages)
|
|
continue;
|
|
if (!mem_cgroup_same_or_subtree(root_memcg, memcg))
|
|
continue;
|
|
if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) {
|
|
if (cpu == curcpu)
|
|
drain_local_stock(&stock->work);
|
|
else
|
|
schedule_work_on(cpu, &stock->work);
|
|
}
|
|
}
|
|
put_cpu();
|
|
|
|
if (!sync)
|
|
goto out;
|
|
|
|
for_each_online_cpu(cpu) {
|
|
struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
|
|
if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags))
|
|
flush_work(&stock->work);
|
|
}
|
|
out:
|
|
put_online_cpus();
|
|
}
|
|
|
|
/*
|
|
* Tries to drain stocked charges in other cpus. This function is asynchronous
|
|
* and just put a work per cpu for draining localy on each cpu. Caller can
|
|
* expects some charges will be back to res_counter later but cannot wait for
|
|
* it.
|
|
*/
|
|
static void drain_all_stock_async(struct mem_cgroup *root_memcg)
|
|
{
|
|
/*
|
|
* If someone calls draining, avoid adding more kworker runs.
|
|
*/
|
|
if (!mutex_trylock(&percpu_charge_mutex))
|
|
return;
|
|
drain_all_stock(root_memcg, false);
|
|
mutex_unlock(&percpu_charge_mutex);
|
|
}
|
|
|
|
/* This is a synchronous drain interface. */
|
|
static void drain_all_stock_sync(struct mem_cgroup *root_memcg)
|
|
{
|
|
/* called when force_empty is called */
|
|
mutex_lock(&percpu_charge_mutex);
|
|
drain_all_stock(root_memcg, true);
|
|
mutex_unlock(&percpu_charge_mutex);
|
|
}
|
|
|
|
/*
|
|
* This function drains percpu counter value from DEAD cpu and
|
|
* move it to local cpu. Note that this function can be preempted.
|
|
*/
|
|
static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu)
|
|
{
|
|
int i;
|
|
|
|
spin_lock(&memcg->pcp_counter_lock);
|
|
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
|
|
long x = per_cpu(memcg->stat->count[i], cpu);
|
|
|
|
per_cpu(memcg->stat->count[i], cpu) = 0;
|
|
memcg->nocpu_base.count[i] += x;
|
|
}
|
|
for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
|
|
unsigned long x = per_cpu(memcg->stat->events[i], cpu);
|
|
|
|
per_cpu(memcg->stat->events[i], cpu) = 0;
|
|
memcg->nocpu_base.events[i] += x;
|
|
}
|
|
spin_unlock(&memcg->pcp_counter_lock);
|
|
}
|
|
|
|
static int memcg_cpu_hotplug_callback(struct notifier_block *nb,
|
|
unsigned long action,
|
|
void *hcpu)
|
|
{
|
|
int cpu = (unsigned long)hcpu;
|
|
struct memcg_stock_pcp *stock;
|
|
struct mem_cgroup *iter;
|
|
|
|
if (action == CPU_ONLINE)
|
|
return NOTIFY_OK;
|
|
|
|
if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
|
|
return NOTIFY_OK;
|
|
|
|
for_each_mem_cgroup(iter)
|
|
mem_cgroup_drain_pcp_counter(iter, cpu);
|
|
|
|
stock = &per_cpu(memcg_stock, cpu);
|
|
drain_stock(stock);
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
|
|
/* See __mem_cgroup_try_charge() for details */
|
|
enum {
|
|
CHARGE_OK, /* success */
|
|
CHARGE_RETRY, /* need to retry but retry is not bad */
|
|
CHARGE_NOMEM, /* we can't do more. return -ENOMEM */
|
|
CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */
|
|
};
|
|
|
|
static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
|
|
unsigned int nr_pages, unsigned int min_pages,
|
|
bool invoke_oom)
|
|
{
|
|
unsigned long csize = nr_pages * PAGE_SIZE;
|
|
struct mem_cgroup *mem_over_limit;
|
|
struct res_counter *fail_res;
|
|
unsigned long flags = 0;
|
|
int ret;
|
|
|
|
ret = res_counter_charge(&memcg->res, csize, &fail_res);
|
|
|
|
if (likely(!ret)) {
|
|
if (!do_swap_account)
|
|
return CHARGE_OK;
|
|
ret = res_counter_charge(&memcg->memsw, csize, &fail_res);
|
|
if (likely(!ret))
|
|
return CHARGE_OK;
|
|
|
|
res_counter_uncharge(&memcg->res, csize);
|
|
mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw);
|
|
flags |= MEM_CGROUP_RECLAIM_NOSWAP;
|
|
} else
|
|
mem_over_limit = mem_cgroup_from_res_counter(fail_res, res);
|
|
/*
|
|
* Never reclaim on behalf of optional batching, retry with a
|
|
* single page instead.
|
|
*/
|
|
if (nr_pages > min_pages)
|
|
return CHARGE_RETRY;
|
|
|
|
if (!(gfp_mask & __GFP_WAIT))
|
|
return CHARGE_WOULDBLOCK;
|
|
|
|
if (gfp_mask & __GFP_NORETRY)
|
|
return CHARGE_NOMEM;
|
|
|
|
ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags);
|
|
if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
|
|
return CHARGE_RETRY;
|
|
/*
|
|
* Even though the limit is exceeded at this point, reclaim
|
|
* may have been able to free some pages. Retry the charge
|
|
* before killing the task.
|
|
*
|
|
* Only for regular pages, though: huge pages are rather
|
|
* unlikely to succeed so close to the limit, and we fall back
|
|
* to regular pages anyway in case of failure.
|
|
*/
|
|
if (nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER) && ret)
|
|
return CHARGE_RETRY;
|
|
|
|
/*
|
|
* At task move, charge accounts can be doubly counted. So, it's
|
|
* better to wait until the end of task_move if something is going on.
|
|
*/
|
|
if (mem_cgroup_wait_acct_move(mem_over_limit))
|
|
return CHARGE_RETRY;
|
|
|
|
if (invoke_oom)
|
|
mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(csize));
|
|
|
|
return CHARGE_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* __mem_cgroup_try_charge() does
|
|
* 1. detect memcg to be charged against from passed *mm and *ptr,
|
|
* 2. update res_counter
|
|
* 3. call memory reclaim if necessary.
|
|
*
|
|
* In some special case, if the task is fatal, fatal_signal_pending() or
|
|
* has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
|
|
* to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
|
|
* as possible without any hazards. 2: all pages should have a valid
|
|
* pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
|
|
* pointer, that is treated as a charge to root_mem_cgroup.
|
|
*
|
|
* So __mem_cgroup_try_charge() will return
|
|
* 0 ... on success, filling *ptr with a valid memcg pointer.
|
|
* -ENOMEM ... charge failure because of resource limits.
|
|
* -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
|
|
*
|
|
* Unlike the exported interface, an "oom" parameter is added. if oom==true,
|
|
* the oom-killer can be invoked.
|
|
*/
|
|
static int __mem_cgroup_try_charge(struct mm_struct *mm,
|
|
gfp_t gfp_mask,
|
|
unsigned int nr_pages,
|
|
struct mem_cgroup **ptr,
|
|
bool oom)
|
|
{
|
|
unsigned int batch = max(CHARGE_BATCH, nr_pages);
|
|
int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
|
|
struct mem_cgroup *memcg = NULL;
|
|
int ret;
|
|
|
|
/*
|
|
* Unlike gloval-vm's OOM-kill, we're not in memory shortage
|
|
* in system level. So, allow to go ahead dying process in addition to
|
|
* MEMDIE process.
|
|
*/
|
|
if (unlikely(test_thread_flag(TIF_MEMDIE)
|
|
|| fatal_signal_pending(current)))
|
|
goto bypass;
|
|
|
|
if (unlikely(task_in_memcg_oom(current)))
|
|
goto nomem;
|
|
|
|
if (gfp_mask & __GFP_NOFAIL)
|
|
oom = false;
|
|
|
|
/*
|
|
* We always charge the cgroup the mm_struct belongs to.
|
|
* The mm_struct's mem_cgroup changes on task migration if the
|
|
* thread group leader migrates. It's possible that mm is not
|
|
* set, if so charge the root memcg (happens for pagecache usage).
|
|
*/
|
|
if (!*ptr && !mm)
|
|
*ptr = root_mem_cgroup;
|
|
again:
|
|
if (*ptr) { /* css should be a valid one */
|
|
memcg = *ptr;
|
|
if (mem_cgroup_is_root(memcg))
|
|
goto done;
|
|
if (consume_stock(memcg, nr_pages))
|
|
goto done;
|
|
css_get(&memcg->css);
|
|
} else {
|
|
struct task_struct *p;
|
|
|
|
rcu_read_lock();
|
|
p = rcu_dereference(mm->owner);
|
|
/*
|
|
* Because we don't have task_lock(), "p" can exit.
|
|
* In that case, "memcg" can point to root or p can be NULL with
|
|
* race with swapoff. Then, we have small risk of mis-accouning.
|
|
* But such kind of mis-account by race always happens because
|
|
* we don't have cgroup_mutex(). It's overkill and we allo that
|
|
* small race, here.
|
|
* (*) swapoff at el will charge against mm-struct not against
|
|
* task-struct. So, mm->owner can be NULL.
|
|
*/
|
|
memcg = mem_cgroup_from_task(p);
|
|
if (!memcg)
|
|
memcg = root_mem_cgroup;
|
|
if (mem_cgroup_is_root(memcg)) {
|
|
rcu_read_unlock();
|
|
goto done;
|
|
}
|
|
if (consume_stock(memcg, nr_pages)) {
|
|
/*
|
|
* It seems dagerous to access memcg without css_get().
|
|
* But considering how consume_stok works, it's not
|
|
* necessary. If consume_stock success, some charges
|
|
* from this memcg are cached on this cpu. So, we
|
|
* don't need to call css_get()/css_tryget() before
|
|
* calling consume_stock().
|
|
*/
|
|
rcu_read_unlock();
|
|
goto done;
|
|
}
|
|
/* after here, we may be blocked. we need to get refcnt */
|
|
if (!css_tryget(&memcg->css)) {
|
|
rcu_read_unlock();
|
|
goto again;
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
do {
|
|
bool invoke_oom = oom && !nr_oom_retries;
|
|
|
|
/* If killed, bypass charge */
|
|
if (fatal_signal_pending(current)) {
|
|
css_put(&memcg->css);
|
|
goto bypass;
|
|
}
|
|
|
|
ret = mem_cgroup_do_charge(memcg, gfp_mask, batch,
|
|
nr_pages, invoke_oom);
|
|
switch (ret) {
|
|
case CHARGE_OK:
|
|
break;
|
|
case CHARGE_RETRY: /* not in OOM situation but retry */
|
|
batch = nr_pages;
|
|
css_put(&memcg->css);
|
|
memcg = NULL;
|
|
goto again;
|
|
case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */
|
|
css_put(&memcg->css);
|
|
goto nomem;
|
|
case CHARGE_NOMEM: /* OOM routine works */
|
|
if (!oom || invoke_oom) {
|
|
css_put(&memcg->css);
|
|
goto nomem;
|
|
}
|
|
nr_oom_retries--;
|
|
break;
|
|
}
|
|
} while (ret != CHARGE_OK);
|
|
|
|
if (batch > nr_pages)
|
|
refill_stock(memcg, batch - nr_pages);
|
|
css_put(&memcg->css);
|
|
done:
|
|
*ptr = memcg;
|
|
return 0;
|
|
nomem:
|
|
if (!(gfp_mask & __GFP_NOFAIL)) {
|
|
*ptr = NULL;
|
|
return -ENOMEM;
|
|
}
|
|
bypass:
|
|
*ptr = root_mem_cgroup;
|
|
return -EINTR;
|
|
}
|
|
|
|
/*
|
|
* Somemtimes we have to undo a charge we got by try_charge().
|
|
* This function is for that and do uncharge, put css's refcnt.
|
|
* gotten by try_charge().
|
|
*/
|
|
static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg,
|
|
unsigned int nr_pages)
|
|
{
|
|
if (!mem_cgroup_is_root(memcg)) {
|
|
unsigned long bytes = nr_pages * PAGE_SIZE;
|
|
|
|
res_counter_uncharge(&memcg->res, bytes);
|
|
if (do_swap_account)
|
|
res_counter_uncharge(&memcg->memsw, bytes);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
|
|
* This is useful when moving usage to parent cgroup.
|
|
*/
|
|
static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg,
|
|
unsigned int nr_pages)
|
|
{
|
|
unsigned long bytes = nr_pages * PAGE_SIZE;
|
|
|
|
if (mem_cgroup_is_root(memcg))
|
|
return;
|
|
|
|
res_counter_uncharge_until(&memcg->res, memcg->res.parent, bytes);
|
|
if (do_swap_account)
|
|
res_counter_uncharge_until(&memcg->memsw,
|
|
memcg->memsw.parent, bytes);
|
|
}
|
|
|
|
/*
|
|
* A helper function to get mem_cgroup from ID. must be called under
|
|
* rcu_read_lock(). The caller is responsible for calling css_tryget if
|
|
* the mem_cgroup is used for charging. (dropping refcnt from swap can be
|
|
* called against removed memcg.)
|
|
*/
|
|
static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
|
|
{
|
|
/* ID 0 is unused ID */
|
|
if (!id)
|
|
return NULL;
|
|
return mem_cgroup_from_id(id);
|
|
}
|
|
|
|
struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
struct page_cgroup *pc;
|
|
unsigned short id;
|
|
swp_entry_t ent;
|
|
|
|
VM_BUG_ON_PAGE(!PageLocked(page), page);
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
lock_page_cgroup(pc);
|
|
if (PageCgroupUsed(pc)) {
|
|
memcg = pc->mem_cgroup;
|
|
if (memcg && !css_tryget(&memcg->css))
|
|
memcg = NULL;
|
|
} else if (PageSwapCache(page)) {
|
|
ent.val = page_private(page);
|
|
id = lookup_swap_cgroup_id(ent);
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_lookup(id);
|
|
if (memcg && !css_tryget(&memcg->css))
|
|
memcg = NULL;
|
|
rcu_read_unlock();
|
|
}
|
|
unlock_page_cgroup(pc);
|
|
return memcg;
|
|
}
|
|
|
|
static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
|
|
struct page *page,
|
|
unsigned int nr_pages,
|
|
enum charge_type ctype,
|
|
bool lrucare)
|
|
{
|
|
struct page_cgroup *pc = lookup_page_cgroup(page);
|
|
struct zone *uninitialized_var(zone);
|
|
struct lruvec *lruvec;
|
|
bool was_on_lru = false;
|
|
bool anon;
|
|
|
|
lock_page_cgroup(pc);
|
|
VM_BUG_ON_PAGE(PageCgroupUsed(pc), page);
|
|
/*
|
|
* we don't need page_cgroup_lock about tail pages, becase they are not
|
|
* accessed by any other context at this point.
|
|
*/
|
|
|
|
/*
|
|
* In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
|
|
* may already be on some other mem_cgroup's LRU. Take care of it.
|
|
*/
|
|
if (lrucare) {
|
|
zone = page_zone(page);
|
|
spin_lock_irq(&zone->lru_lock);
|
|
if (PageLRU(page)) {
|
|
lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup);
|
|
ClearPageLRU(page);
|
|
del_page_from_lru_list(page, lruvec, page_lru(page));
|
|
was_on_lru = true;
|
|
}
|
|
}
|
|
|
|
pc->mem_cgroup = memcg;
|
|
/*
|
|
* We access a page_cgroup asynchronously without lock_page_cgroup().
|
|
* Especially when a page_cgroup is taken from a page, pc->mem_cgroup
|
|
* is accessed after testing USED bit. To make pc->mem_cgroup visible
|
|
* before USED bit, we need memory barrier here.
|
|
* See mem_cgroup_add_lru_list(), etc.
|
|
*/
|
|
smp_wmb();
|
|
SetPageCgroupUsed(pc);
|
|
|
|
if (lrucare) {
|
|
if (was_on_lru) {
|
|
lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup);
|
|
VM_BUG_ON_PAGE(PageLRU(page), page);
|
|
SetPageLRU(page);
|
|
add_page_to_lru_list(page, lruvec, page_lru(page));
|
|
}
|
|
spin_unlock_irq(&zone->lru_lock);
|
|
}
|
|
|
|
if (ctype == MEM_CGROUP_CHARGE_TYPE_ANON)
|
|
anon = true;
|
|
else
|
|
anon = false;
|
|
|
|
mem_cgroup_charge_statistics(memcg, page, anon, nr_pages);
|
|
unlock_page_cgroup(pc);
|
|
|
|
/*
|
|
* "charge_statistics" updated event counter. Then, check it.
|
|
* Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
|
|
* if they exceeds softlimit.
|
|
*/
|
|
memcg_check_events(memcg, page);
|
|
}
|
|
|
|
static DEFINE_MUTEX(set_limit_mutex);
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
static DEFINE_MUTEX(activate_kmem_mutex);
|
|
|
|
static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg) &&
|
|
memcg_kmem_is_active(memcg);
|
|
}
|
|
|
|
/*
|
|
* This is a bit cumbersome, but it is rarely used and avoids a backpointer
|
|
* in the memcg_cache_params struct.
|
|
*/
|
|
static struct kmem_cache *memcg_params_to_cache(struct memcg_cache_params *p)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
|
|
VM_BUG_ON(p->is_root_cache);
|
|
cachep = p->root_cache;
|
|
return cache_from_memcg_idx(cachep, memcg_cache_id(p->memcg));
|
|
}
|
|
|
|
#ifdef CONFIG_SLABINFO
|
|
static int mem_cgroup_slabinfo_read(struct seq_file *m, void *v)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
|
|
struct memcg_cache_params *params;
|
|
|
|
if (!memcg_can_account_kmem(memcg))
|
|
return -EIO;
|
|
|
|
print_slabinfo_header(m);
|
|
|
|
mutex_lock(&memcg->slab_caches_mutex);
|
|
list_for_each_entry(params, &memcg->memcg_slab_caches, list)
|
|
cache_show(memcg_params_to_cache(params), m);
|
|
mutex_unlock(&memcg->slab_caches_mutex);
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
|
|
{
|
|
struct res_counter *fail_res;
|
|
struct mem_cgroup *_memcg;
|
|
int ret = 0;
|
|
|
|
ret = res_counter_charge(&memcg->kmem, size, &fail_res);
|
|
if (ret)
|
|
return ret;
|
|
|
|
_memcg = memcg;
|
|
ret = __mem_cgroup_try_charge(NULL, gfp, size >> PAGE_SHIFT,
|
|
&_memcg, oom_gfp_allowed(gfp));
|
|
|
|
if (ret == -EINTR) {
|
|
/*
|
|
* __mem_cgroup_try_charge() chosed to bypass to root due to
|
|
* OOM kill or fatal signal. Since our only options are to
|
|
* either fail the allocation or charge it to this cgroup, do
|
|
* it as a temporary condition. But we can't fail. From a
|
|
* kmem/slab perspective, the cache has already been selected,
|
|
* by mem_cgroup_kmem_get_cache(), so it is too late to change
|
|
* our minds.
|
|
*
|
|
* This condition will only trigger if the task entered
|
|
* memcg_charge_kmem in a sane state, but was OOM-killed during
|
|
* __mem_cgroup_try_charge() above. Tasks that were already
|
|
* dying when the allocation triggers should have been already
|
|
* directed to the root cgroup in memcontrol.h
|
|
*/
|
|
res_counter_charge_nofail(&memcg->res, size, &fail_res);
|
|
if (do_swap_account)
|
|
res_counter_charge_nofail(&memcg->memsw, size,
|
|
&fail_res);
|
|
ret = 0;
|
|
} else if (ret)
|
|
res_counter_uncharge(&memcg->kmem, size);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void memcg_uncharge_kmem(struct mem_cgroup *memcg, u64 size)
|
|
{
|
|
res_counter_uncharge(&memcg->res, size);
|
|
if (do_swap_account)
|
|
res_counter_uncharge(&memcg->memsw, size);
|
|
|
|
/* Not down to 0 */
|
|
if (res_counter_uncharge(&memcg->kmem, size))
|
|
return;
|
|
|
|
/*
|
|
* Releases a reference taken in kmem_cgroup_css_offline in case
|
|
* this last uncharge is racing with the offlining code or it is
|
|
* outliving the memcg existence.
|
|
*
|
|
* The memory barrier imposed by test&clear is paired with the
|
|
* explicit one in memcg_kmem_mark_dead().
|
|
*/
|
|
if (memcg_kmem_test_and_clear_dead(memcg))
|
|
css_put(&memcg->css);
|
|
}
|
|
|
|
/*
|
|
* helper for acessing a memcg's index. It will be used as an index in the
|
|
* child cache array in kmem_cache, and also to derive its name. This function
|
|
* will return -1 when this is not a kmem-limited memcg.
|
|
*/
|
|
int memcg_cache_id(struct mem_cgroup *memcg)
|
|
{
|
|
return memcg ? memcg->kmemcg_id : -1;
|
|
}
|
|
|
|
static size_t memcg_caches_array_size(int num_groups)
|
|
{
|
|
ssize_t size;
|
|
if (num_groups <= 0)
|
|
return 0;
|
|
|
|
size = 2 * num_groups;
|
|
if (size < MEMCG_CACHES_MIN_SIZE)
|
|
size = MEMCG_CACHES_MIN_SIZE;
|
|
else if (size > MEMCG_CACHES_MAX_SIZE)
|
|
size = MEMCG_CACHES_MAX_SIZE;
|
|
|
|
return size;
|
|
}
|
|
|
|
/*
|
|
* We should update the current array size iff all caches updates succeed. This
|
|
* can only be done from the slab side. The slab mutex needs to be held when
|
|
* calling this.
|
|
*/
|
|
void memcg_update_array_size(int num)
|
|
{
|
|
if (num > memcg_limited_groups_array_size)
|
|
memcg_limited_groups_array_size = memcg_caches_array_size(num);
|
|
}
|
|
|
|
static void kmem_cache_destroy_work_func(struct work_struct *w);
|
|
|
|
int memcg_update_cache_size(struct kmem_cache *s, int num_groups)
|
|
{
|
|
struct memcg_cache_params *cur_params = s->memcg_params;
|
|
|
|
VM_BUG_ON(!is_root_cache(s));
|
|
|
|
if (num_groups > memcg_limited_groups_array_size) {
|
|
int i;
|
|
struct memcg_cache_params *new_params;
|
|
ssize_t size = memcg_caches_array_size(num_groups);
|
|
|
|
size *= sizeof(void *);
|
|
size += offsetof(struct memcg_cache_params, memcg_caches);
|
|
|
|
new_params = kzalloc(size, GFP_KERNEL);
|
|
if (!new_params)
|
|
return -ENOMEM;
|
|
|
|
new_params->is_root_cache = true;
|
|
|
|
/*
|
|
* There is the chance it will be bigger than
|
|
* memcg_limited_groups_array_size, if we failed an allocation
|
|
* in a cache, in which case all caches updated before it, will
|
|
* have a bigger array.
|
|
*
|
|
* But if that is the case, the data after
|
|
* memcg_limited_groups_array_size is certainly unused
|
|
*/
|
|
for (i = 0; i < memcg_limited_groups_array_size; i++) {
|
|
if (!cur_params->memcg_caches[i])
|
|
continue;
|
|
new_params->memcg_caches[i] =
|
|
cur_params->memcg_caches[i];
|
|
}
|
|
|
|
/*
|
|
* Ideally, we would wait until all caches succeed, and only
|
|
* then free the old one. But this is not worth the extra
|
|
* pointer per-cache we'd have to have for this.
|
|
*
|
|
* It is not a big deal if some caches are left with a size
|
|
* bigger than the others. And all updates will reset this
|
|
* anyway.
|
|
*/
|
|
rcu_assign_pointer(s->memcg_params, new_params);
|
|
if (cur_params)
|
|
kfree_rcu(cur_params, rcu_head);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int memcg_alloc_cache_params(struct mem_cgroup *memcg, struct kmem_cache *s,
|
|
struct kmem_cache *root_cache)
|
|
{
|
|
size_t size;
|
|
|
|
if (!memcg_kmem_enabled())
|
|
return 0;
|
|
|
|
if (!memcg) {
|
|
size = offsetof(struct memcg_cache_params, memcg_caches);
|
|
size += memcg_limited_groups_array_size * sizeof(void *);
|
|
} else
|
|
size = sizeof(struct memcg_cache_params);
|
|
|
|
s->memcg_params = kzalloc(size, GFP_KERNEL);
|
|
if (!s->memcg_params)
|
|
return -ENOMEM;
|
|
|
|
if (memcg) {
|
|
s->memcg_params->memcg = memcg;
|
|
s->memcg_params->root_cache = root_cache;
|
|
INIT_WORK(&s->memcg_params->destroy,
|
|
kmem_cache_destroy_work_func);
|
|
} else
|
|
s->memcg_params->is_root_cache = true;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void memcg_free_cache_params(struct kmem_cache *s)
|
|
{
|
|
kfree(s->memcg_params);
|
|
}
|
|
|
|
void memcg_register_cache(struct kmem_cache *s)
|
|
{
|
|
struct kmem_cache *root;
|
|
struct mem_cgroup *memcg;
|
|
int id;
|
|
|
|
if (is_root_cache(s))
|
|
return;
|
|
|
|
/*
|
|
* Holding the slab_mutex assures nobody will touch the memcg_caches
|
|
* array while we are modifying it.
|
|
*/
|
|
lockdep_assert_held(&slab_mutex);
|
|
|
|
root = s->memcg_params->root_cache;
|
|
memcg = s->memcg_params->memcg;
|
|
id = memcg_cache_id(memcg);
|
|
|
|
css_get(&memcg->css);
|
|
|
|
|
|
/*
|
|
* Since readers won't lock (see cache_from_memcg_idx()), we need a
|
|
* barrier here to ensure nobody will see the kmem_cache partially
|
|
* initialized.
|
|
*/
|
|
smp_wmb();
|
|
|
|
/*
|
|
* Initialize the pointer to this cache in its parent's memcg_params
|
|
* before adding it to the memcg_slab_caches list, otherwise we can
|
|
* fail to convert memcg_params_to_cache() while traversing the list.
|
|
*/
|
|
VM_BUG_ON(root->memcg_params->memcg_caches[id]);
|
|
root->memcg_params->memcg_caches[id] = s;
|
|
|
|
mutex_lock(&memcg->slab_caches_mutex);
|
|
list_add(&s->memcg_params->list, &memcg->memcg_slab_caches);
|
|
mutex_unlock(&memcg->slab_caches_mutex);
|
|
}
|
|
|
|
void memcg_unregister_cache(struct kmem_cache *s)
|
|
{
|
|
struct kmem_cache *root;
|
|
struct mem_cgroup *memcg;
|
|
int id;
|
|
|
|
if (is_root_cache(s))
|
|
return;
|
|
|
|
/*
|
|
* Holding the slab_mutex assures nobody will touch the memcg_caches
|
|
* array while we are modifying it.
|
|
*/
|
|
lockdep_assert_held(&slab_mutex);
|
|
|
|
root = s->memcg_params->root_cache;
|
|
memcg = s->memcg_params->memcg;
|
|
id = memcg_cache_id(memcg);
|
|
|
|
mutex_lock(&memcg->slab_caches_mutex);
|
|
list_del(&s->memcg_params->list);
|
|
mutex_unlock(&memcg->slab_caches_mutex);
|
|
|
|
/*
|
|
* Clear the pointer to this cache in its parent's memcg_params only
|
|
* after removing it from the memcg_slab_caches list, otherwise we can
|
|
* fail to convert memcg_params_to_cache() while traversing the list.
|
|
*/
|
|
VM_BUG_ON(!root->memcg_params->memcg_caches[id]);
|
|
root->memcg_params->memcg_caches[id] = NULL;
|
|
|
|
css_put(&memcg->css);
|
|
}
|
|
|
|
/*
|
|
* During the creation a new cache, we need to disable our accounting mechanism
|
|
* altogether. This is true even if we are not creating, but rather just
|
|
* enqueing new caches to be created.
|
|
*
|
|
* This is because that process will trigger allocations; some visible, like
|
|
* explicit kmallocs to auxiliary data structures, name strings and internal
|
|
* cache structures; some well concealed, like INIT_WORK() that can allocate
|
|
* objects during debug.
|
|
*
|
|
* If any allocation happens during memcg_kmem_get_cache, we will recurse back
|
|
* to it. This may not be a bounded recursion: since the first cache creation
|
|
* failed to complete (waiting on the allocation), we'll just try to create the
|
|
* cache again, failing at the same point.
|
|
*
|
|
* memcg_kmem_get_cache is prepared to abort after seeing a positive count of
|
|
* memcg_kmem_skip_account. So we enclose anything that might allocate memory
|
|
* inside the following two functions.
|
|
*/
|
|
static inline void memcg_stop_kmem_account(void)
|
|
{
|
|
VM_BUG_ON(!current->mm);
|
|
current->memcg_kmem_skip_account++;
|
|
}
|
|
|
|
static inline void memcg_resume_kmem_account(void)
|
|
{
|
|
VM_BUG_ON(!current->mm);
|
|
current->memcg_kmem_skip_account--;
|
|
}
|
|
|
|
static void kmem_cache_destroy_work_func(struct work_struct *w)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
struct memcg_cache_params *p;
|
|
|
|
p = container_of(w, struct memcg_cache_params, destroy);
|
|
|
|
cachep = memcg_params_to_cache(p);
|
|
|
|
/*
|
|
* If we get down to 0 after shrink, we could delete right away.
|
|
* However, memcg_release_pages() already puts us back in the workqueue
|
|
* in that case. If we proceed deleting, we'll get a dangling
|
|
* reference, and removing the object from the workqueue in that case
|
|
* is unnecessary complication. We are not a fast path.
|
|
*
|
|
* Note that this case is fundamentally different from racing with
|
|
* shrink_slab(): if memcg_cgroup_destroy_cache() is called in
|
|
* kmem_cache_shrink, not only we would be reinserting a dead cache
|
|
* into the queue, but doing so from inside the worker racing to
|
|
* destroy it.
|
|
*
|
|
* So if we aren't down to zero, we'll just schedule a worker and try
|
|
* again
|
|
*/
|
|
if (atomic_read(&cachep->memcg_params->nr_pages) != 0)
|
|
kmem_cache_shrink(cachep);
|
|
else
|
|
kmem_cache_destroy(cachep);
|
|
}
|
|
|
|
void mem_cgroup_destroy_cache(struct kmem_cache *cachep)
|
|
{
|
|
if (!cachep->memcg_params->dead)
|
|
return;
|
|
|
|
/*
|
|
* There are many ways in which we can get here.
|
|
*
|
|
* We can get to a memory-pressure situation while the delayed work is
|
|
* still pending to run. The vmscan shrinkers can then release all
|
|
* cache memory and get us to destruction. If this is the case, we'll
|
|
* be executed twice, which is a bug (the second time will execute over
|
|
* bogus data). In this case, cancelling the work should be fine.
|
|
*
|
|
* But we can also get here from the worker itself, if
|
|
* kmem_cache_shrink is enough to shake all the remaining objects and
|
|
* get the page count to 0. In this case, we'll deadlock if we try to
|
|
* cancel the work (the worker runs with an internal lock held, which
|
|
* is the same lock we would hold for cancel_work_sync().)
|
|
*
|
|
* Since we can't possibly know who got us here, just refrain from
|
|
* running if there is already work pending
|
|
*/
|
|
if (work_pending(&cachep->memcg_params->destroy))
|
|
return;
|
|
/*
|
|
* We have to defer the actual destroying to a workqueue, because
|
|
* we might currently be in a context that cannot sleep.
|
|
*/
|
|
schedule_work(&cachep->memcg_params->destroy);
|
|
}
|
|
|
|
static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
|
|
struct kmem_cache *s)
|
|
{
|
|
struct kmem_cache *new = NULL;
|
|
static char *tmp_name = NULL;
|
|
static DEFINE_MUTEX(mutex); /* protects tmp_name */
|
|
|
|
BUG_ON(!memcg_can_account_kmem(memcg));
|
|
|
|
mutex_lock(&mutex);
|
|
/*
|
|
* kmem_cache_create_memcg duplicates the given name and
|
|
* cgroup_name for this name requires RCU context.
|
|
* This static temporary buffer is used to prevent from
|
|
* pointless shortliving allocation.
|
|
*/
|
|
if (!tmp_name) {
|
|
tmp_name = kmalloc(PATH_MAX, GFP_KERNEL);
|
|
if (!tmp_name)
|
|
goto out;
|
|
}
|
|
|
|
rcu_read_lock();
|
|
snprintf(tmp_name, PATH_MAX, "%s(%d:%s)", s->name,
|
|
memcg_cache_id(memcg), cgroup_name(memcg->css.cgroup));
|
|
rcu_read_unlock();
|
|
|
|
new = kmem_cache_create_memcg(memcg, tmp_name, s->object_size, s->align,
|
|
(s->flags & ~SLAB_PANIC), s->ctor, s);
|
|
if (new)
|
|
new->allocflags |= __GFP_KMEMCG;
|
|
else
|
|
new = s;
|
|
out:
|
|
mutex_unlock(&mutex);
|
|
return new;
|
|
}
|
|
|
|
void kmem_cache_destroy_memcg_children(struct kmem_cache *s)
|
|
{
|
|
struct kmem_cache *c;
|
|
int i;
|
|
|
|
if (!s->memcg_params)
|
|
return;
|
|
if (!s->memcg_params->is_root_cache)
|
|
return;
|
|
|
|
/*
|
|
* If the cache is being destroyed, we trust that there is no one else
|
|
* requesting objects from it. Even if there are, the sanity checks in
|
|
* kmem_cache_destroy should caught this ill-case.
|
|
*
|
|
* Still, we don't want anyone else freeing memcg_caches under our
|
|
* noses, which can happen if a new memcg comes to life. As usual,
|
|
* we'll take the activate_kmem_mutex to protect ourselves against
|
|
* this.
|
|
*/
|
|
mutex_lock(&activate_kmem_mutex);
|
|
for_each_memcg_cache_index(i) {
|
|
c = cache_from_memcg_idx(s, i);
|
|
if (!c)
|
|
continue;
|
|
|
|
/*
|
|
* We will now manually delete the caches, so to avoid races
|
|
* we need to cancel all pending destruction workers and
|
|
* proceed with destruction ourselves.
|
|
*
|
|
* kmem_cache_destroy() will call kmem_cache_shrink internally,
|
|
* and that could spawn the workers again: it is likely that
|
|
* the cache still have active pages until this very moment.
|
|
* This would lead us back to mem_cgroup_destroy_cache.
|
|
*
|
|
* But that will not execute at all if the "dead" flag is not
|
|
* set, so flip it down to guarantee we are in control.
|
|
*/
|
|
c->memcg_params->dead = false;
|
|
cancel_work_sync(&c->memcg_params->destroy);
|
|
kmem_cache_destroy(c);
|
|
}
|
|
mutex_unlock(&activate_kmem_mutex);
|
|
}
|
|
|
|
struct create_work {
|
|
struct mem_cgroup *memcg;
|
|
struct kmem_cache *cachep;
|
|
struct work_struct work;
|
|
};
|
|
|
|
static void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
struct memcg_cache_params *params;
|
|
|
|
if (!memcg_kmem_is_active(memcg))
|
|
return;
|
|
|
|
mutex_lock(&memcg->slab_caches_mutex);
|
|
list_for_each_entry(params, &memcg->memcg_slab_caches, list) {
|
|
cachep = memcg_params_to_cache(params);
|
|
cachep->memcg_params->dead = true;
|
|
schedule_work(&cachep->memcg_params->destroy);
|
|
}
|
|
mutex_unlock(&memcg->slab_caches_mutex);
|
|
}
|
|
|
|
static void memcg_create_cache_work_func(struct work_struct *w)
|
|
{
|
|
struct create_work *cw;
|
|
|
|
cw = container_of(w, struct create_work, work);
|
|
memcg_create_kmem_cache(cw->memcg, cw->cachep);
|
|
css_put(&cw->memcg->css);
|
|
kfree(cw);
|
|
}
|
|
|
|
/*
|
|
* Enqueue the creation of a per-memcg kmem_cache.
|
|
*/
|
|
static void __memcg_create_cache_enqueue(struct mem_cgroup *memcg,
|
|
struct kmem_cache *cachep)
|
|
{
|
|
struct create_work *cw;
|
|
|
|
cw = kmalloc(sizeof(struct create_work), GFP_NOWAIT);
|
|
if (cw == NULL) {
|
|
css_put(&memcg->css);
|
|
return;
|
|
}
|
|
|
|
cw->memcg = memcg;
|
|
cw->cachep = cachep;
|
|
|
|
INIT_WORK(&cw->work, memcg_create_cache_work_func);
|
|
schedule_work(&cw->work);
|
|
}
|
|
|
|
static void memcg_create_cache_enqueue(struct mem_cgroup *memcg,
|
|
struct kmem_cache *cachep)
|
|
{
|
|
/*
|
|
* We need to stop accounting when we kmalloc, because if the
|
|
* corresponding kmalloc cache is not yet created, the first allocation
|
|
* in __memcg_create_cache_enqueue will recurse.
|
|
*
|
|
* However, it is better to enclose the whole function. Depending on
|
|
* the debugging options enabled, INIT_WORK(), for instance, can
|
|
* trigger an allocation. This too, will make us recurse. Because at
|
|
* this point we can't allow ourselves back into memcg_kmem_get_cache,
|
|
* the safest choice is to do it like this, wrapping the whole function.
|
|
*/
|
|
memcg_stop_kmem_account();
|
|
__memcg_create_cache_enqueue(memcg, cachep);
|
|
memcg_resume_kmem_account();
|
|
}
|
|
/*
|
|
* Return the kmem_cache we're supposed to use for a slab allocation.
|
|
* We try to use the current memcg's version of the cache.
|
|
*
|
|
* If the cache does not exist yet, if we are the first user of it,
|
|
* we either create it immediately, if possible, or create it asynchronously
|
|
* in a workqueue.
|
|
* In the latter case, we will let the current allocation go through with
|
|
* the original cache.
|
|
*
|
|
* Can't be called in interrupt context or from kernel threads.
|
|
* This function needs to be called with rcu_read_lock() held.
|
|
*/
|
|
struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep,
|
|
gfp_t gfp)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
struct kmem_cache *memcg_cachep;
|
|
|
|
VM_BUG_ON(!cachep->memcg_params);
|
|
VM_BUG_ON(!cachep->memcg_params->is_root_cache);
|
|
|
|
if (!current->mm || current->memcg_kmem_skip_account)
|
|
return cachep;
|
|
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_from_task(rcu_dereference(current->mm->owner));
|
|
|
|
if (!memcg_can_account_kmem(memcg))
|
|
goto out;
|
|
|
|
memcg_cachep = cache_from_memcg_idx(cachep, memcg_cache_id(memcg));
|
|
if (likely(memcg_cachep)) {
|
|
cachep = memcg_cachep;
|
|
goto out;
|
|
}
|
|
|
|
/* The corresponding put will be done in the workqueue. */
|
|
if (!css_tryget(&memcg->css))
|
|
goto out;
|
|
rcu_read_unlock();
|
|
|
|
/*
|
|
* If we are in a safe context (can wait, and not in interrupt
|
|
* context), we could be be predictable and return right away.
|
|
* This would guarantee that the allocation being performed
|
|
* already belongs in the new cache.
|
|
*
|
|
* However, there are some clashes that can arrive from locking.
|
|
* For instance, because we acquire the slab_mutex while doing
|
|
* kmem_cache_dup, this means no further allocation could happen
|
|
* with the slab_mutex held.
|
|
*
|
|
* Also, because cache creation issue get_online_cpus(), this
|
|
* creates a lock chain: memcg_slab_mutex -> cpu_hotplug_mutex,
|
|
* that ends up reversed during cpu hotplug. (cpuset allocates
|
|
* a bunch of GFP_KERNEL memory during cpuup). Due to all that,
|
|
* better to defer everything.
|
|
*/
|
|
memcg_create_cache_enqueue(memcg, cachep);
|
|
return cachep;
|
|
out:
|
|
rcu_read_unlock();
|
|
return cachep;
|
|
}
|
|
EXPORT_SYMBOL(__memcg_kmem_get_cache);
|
|
|
|
/*
|
|
* We need to verify if the allocation against current->mm->owner's memcg is
|
|
* possible for the given order. But the page is not allocated yet, so we'll
|
|
* need a further commit step to do the final arrangements.
|
|
*
|
|
* It is possible for the task to switch cgroups in this mean time, so at
|
|
* commit time, we can't rely on task conversion any longer. We'll then use
|
|
* the handle argument to return to the caller which cgroup we should commit
|
|
* against. We could also return the memcg directly and avoid the pointer
|
|
* passing, but a boolean return value gives better semantics considering
|
|
* the compiled-out case as well.
|
|
*
|
|
* Returning true means the allocation is possible.
|
|
*/
|
|
bool
|
|
__memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
int ret;
|
|
|
|
*_memcg = NULL;
|
|
|
|
/*
|
|
* Disabling accounting is only relevant for some specific memcg
|
|
* internal allocations. Therefore we would initially not have such
|
|
* check here, since direct calls to the page allocator that are marked
|
|
* with GFP_KMEMCG only happen outside memcg core. We are mostly
|
|
* concerned with cache allocations, and by having this test at
|
|
* memcg_kmem_get_cache, we are already able to relay the allocation to
|
|
* the root cache and bypass the memcg cache altogether.
|
|
*
|
|
* There is one exception, though: the SLUB allocator does not create
|
|
* large order caches, but rather service large kmallocs directly from
|
|
* the page allocator. Therefore, the following sequence when backed by
|
|
* the SLUB allocator:
|
|
*
|
|
* memcg_stop_kmem_account();
|
|
* kmalloc(<large_number>)
|
|
* memcg_resume_kmem_account();
|
|
*
|
|
* would effectively ignore the fact that we should skip accounting,
|
|
* since it will drive us directly to this function without passing
|
|
* through the cache selector memcg_kmem_get_cache. Such large
|
|
* allocations are extremely rare but can happen, for instance, for the
|
|
* cache arrays. We bring this test here.
|
|
*/
|
|
if (!current->mm || current->memcg_kmem_skip_account)
|
|
return true;
|
|
|
|
memcg = try_get_mem_cgroup_from_mm(current->mm);
|
|
|
|
/*
|
|
* very rare case described in mem_cgroup_from_task. Unfortunately there
|
|
* isn't much we can do without complicating this too much, and it would
|
|
* be gfp-dependent anyway. Just let it go
|
|
*/
|
|
if (unlikely(!memcg))
|
|
return true;
|
|
|
|
if (!memcg_can_account_kmem(memcg)) {
|
|
css_put(&memcg->css);
|
|
return true;
|
|
}
|
|
|
|
ret = memcg_charge_kmem(memcg, gfp, PAGE_SIZE << order);
|
|
if (!ret)
|
|
*_memcg = memcg;
|
|
|
|
css_put(&memcg->css);
|
|
return (ret == 0);
|
|
}
|
|
|
|
void __memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg,
|
|
int order)
|
|
{
|
|
struct page_cgroup *pc;
|
|
|
|
VM_BUG_ON(mem_cgroup_is_root(memcg));
|
|
|
|
/* The page allocation failed. Revert */
|
|
if (!page) {
|
|
memcg_uncharge_kmem(memcg, PAGE_SIZE << order);
|
|
return;
|
|
}
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
lock_page_cgroup(pc);
|
|
pc->mem_cgroup = memcg;
|
|
SetPageCgroupUsed(pc);
|
|
unlock_page_cgroup(pc);
|
|
}
|
|
|
|
void __memcg_kmem_uncharge_pages(struct page *page, int order)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
struct page_cgroup *pc;
|
|
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
/*
|
|
* Fast unlocked return. Theoretically might have changed, have to
|
|
* check again after locking.
|
|
*/
|
|
if (!PageCgroupUsed(pc))
|
|
return;
|
|
|
|
lock_page_cgroup(pc);
|
|
if (PageCgroupUsed(pc)) {
|
|
memcg = pc->mem_cgroup;
|
|
ClearPageCgroupUsed(pc);
|
|
}
|
|
unlock_page_cgroup(pc);
|
|
|
|
/*
|
|
* We trust that only if there is a memcg associated with the page, it
|
|
* is a valid allocation
|
|
*/
|
|
if (!memcg)
|
|
return;
|
|
|
|
VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg), page);
|
|
memcg_uncharge_kmem(memcg, PAGE_SIZE << order);
|
|
}
|
|
#else
|
|
static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
#endif /* CONFIG_MEMCG_KMEM */
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
|
|
#define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION)
|
|
/*
|
|
* Because tail pages are not marked as "used", set it. We're under
|
|
* zone->lru_lock, 'splitting on pmd' and compound_lock.
|
|
* charge/uncharge will be never happen and move_account() is done under
|
|
* compound_lock(), so we don't have to take care of races.
|
|
*/
|
|
void mem_cgroup_split_huge_fixup(struct page *head)
|
|
{
|
|
struct page_cgroup *head_pc = lookup_page_cgroup(head);
|
|
struct page_cgroup *pc;
|
|
struct mem_cgroup *memcg;
|
|
int i;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
memcg = head_pc->mem_cgroup;
|
|
for (i = 1; i < HPAGE_PMD_NR; i++) {
|
|
pc = head_pc + i;
|
|
pc->mem_cgroup = memcg;
|
|
smp_wmb();/* see __commit_charge() */
|
|
pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT;
|
|
}
|
|
__this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE],
|
|
HPAGE_PMD_NR);
|
|
}
|
|
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
|
|
|
|
static inline
|
|
void mem_cgroup_move_account_page_stat(struct mem_cgroup *from,
|
|
struct mem_cgroup *to,
|
|
unsigned int nr_pages,
|
|
enum mem_cgroup_stat_index idx)
|
|
{
|
|
/* Update stat data for mem_cgroup */
|
|
preempt_disable();
|
|
__this_cpu_sub(from->stat->count[idx], nr_pages);
|
|
__this_cpu_add(to->stat->count[idx], nr_pages);
|
|
preempt_enable();
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_move_account - move account of the page
|
|
* @page: the page
|
|
* @nr_pages: number of regular pages (>1 for huge pages)
|
|
* @pc: page_cgroup of the page.
|
|
* @from: mem_cgroup which the page is moved from.
|
|
* @to: mem_cgroup which the page is moved to. @from != @to.
|
|
*
|
|
* The caller must confirm following.
|
|
* - page is not on LRU (isolate_page() is useful.)
|
|
* - compound_lock is held when nr_pages > 1
|
|
*
|
|
* This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
|
|
* from old cgroup.
|
|
*/
|
|
static int mem_cgroup_move_account(struct page *page,
|
|
unsigned int nr_pages,
|
|
struct page_cgroup *pc,
|
|
struct mem_cgroup *from,
|
|
struct mem_cgroup *to)
|
|
{
|
|
unsigned long flags;
|
|
int ret;
|
|
bool anon = PageAnon(page);
|
|
|
|
VM_BUG_ON(from == to);
|
|
VM_BUG_ON_PAGE(PageLRU(page), page);
|
|
/*
|
|
* The page is isolated from LRU. So, collapse function
|
|
* will not handle this page. But page splitting can happen.
|
|
* Do this check under compound_page_lock(). The caller should
|
|
* hold it.
|
|
*/
|
|
ret = -EBUSY;
|
|
if (nr_pages > 1 && !PageTransHuge(page))
|
|
goto out;
|
|
|
|
lock_page_cgroup(pc);
|
|
|
|
ret = -EINVAL;
|
|
if (!PageCgroupUsed(pc) || pc->mem_cgroup != from)
|
|
goto unlock;
|
|
|
|
move_lock_mem_cgroup(from, &flags);
|
|
|
|
if (!anon && page_mapped(page))
|
|
mem_cgroup_move_account_page_stat(from, to, nr_pages,
|
|
MEM_CGROUP_STAT_FILE_MAPPED);
|
|
|
|
if (PageWriteback(page))
|
|
mem_cgroup_move_account_page_stat(from, to, nr_pages,
|
|
MEM_CGROUP_STAT_WRITEBACK);
|
|
|
|
mem_cgroup_charge_statistics(from, page, anon, -nr_pages);
|
|
|
|
/* caller should have done css_get */
|
|
pc->mem_cgroup = to;
|
|
mem_cgroup_charge_statistics(to, page, anon, nr_pages);
|
|
move_unlock_mem_cgroup(from, &flags);
|
|
ret = 0;
|
|
unlock:
|
|
unlock_page_cgroup(pc);
|
|
/*
|
|
* check events
|
|
*/
|
|
memcg_check_events(to, page);
|
|
memcg_check_events(from, page);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_move_parent - moves page to the parent group
|
|
* @page: the page to move
|
|
* @pc: page_cgroup of the page
|
|
* @child: page's cgroup
|
|
*
|
|
* move charges to its parent or the root cgroup if the group has no
|
|
* parent (aka use_hierarchy==0).
|
|
* Although this might fail (get_page_unless_zero, isolate_lru_page or
|
|
* mem_cgroup_move_account fails) the failure is always temporary and
|
|
* it signals a race with a page removal/uncharge or migration. In the
|
|
* first case the page is on the way out and it will vanish from the LRU
|
|
* on the next attempt and the call should be retried later.
|
|
* Isolation from the LRU fails only if page has been isolated from
|
|
* the LRU since we looked at it and that usually means either global
|
|
* reclaim or migration going on. The page will either get back to the
|
|
* LRU or vanish.
|
|
* Finaly mem_cgroup_move_account fails only if the page got uncharged
|
|
* (!PageCgroupUsed) or moved to a different group. The page will
|
|
* disappear in the next attempt.
|
|
*/
|
|
static int mem_cgroup_move_parent(struct page *page,
|
|
struct page_cgroup *pc,
|
|
struct mem_cgroup *child)
|
|
{
|
|
struct mem_cgroup *parent;
|
|
unsigned int nr_pages;
|
|
unsigned long uninitialized_var(flags);
|
|
int ret;
|
|
|
|
VM_BUG_ON(mem_cgroup_is_root(child));
|
|
|
|
ret = -EBUSY;
|
|
if (!get_page_unless_zero(page))
|
|
goto out;
|
|
if (isolate_lru_page(page))
|
|
goto put;
|
|
|
|
nr_pages = hpage_nr_pages(page);
|
|
|
|
parent = parent_mem_cgroup(child);
|
|
/*
|
|
* If no parent, move charges to root cgroup.
|
|
*/
|
|
if (!parent)
|
|
parent = root_mem_cgroup;
|
|
|
|
if (nr_pages > 1) {
|
|
VM_BUG_ON_PAGE(!PageTransHuge(page), page);
|
|
flags = compound_lock_irqsave(page);
|
|
}
|
|
|
|
ret = mem_cgroup_move_account(page, nr_pages,
|
|
pc, child, parent);
|
|
if (!ret)
|
|
__mem_cgroup_cancel_local_charge(child, nr_pages);
|
|
|
|
if (nr_pages > 1)
|
|
compound_unlock_irqrestore(page, flags);
|
|
putback_lru_page(page);
|
|
put:
|
|
put_page(page);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Charge the memory controller for page usage.
|
|
* Return
|
|
* 0 if the charge was successful
|
|
* < 0 if the cgroup is over its limit
|
|
*/
|
|
static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
|
|
gfp_t gfp_mask, enum charge_type ctype)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
unsigned int nr_pages = 1;
|
|
bool oom = true;
|
|
int ret;
|
|
|
|
if (PageTransHuge(page)) {
|
|
nr_pages <<= compound_order(page);
|
|
VM_BUG_ON_PAGE(!PageTransHuge(page), page);
|
|
/*
|
|
* Never OOM-kill a process for a huge page. The
|
|
* fault handler will fall back to regular pages.
|
|
*/
|
|
oom = false;
|
|
}
|
|
|
|
ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom);
|
|
if (ret == -ENOMEM)
|
|
return ret;
|
|
__mem_cgroup_commit_charge(memcg, page, nr_pages, ctype, false);
|
|
return 0;
|
|
}
|
|
|
|
int mem_cgroup_newpage_charge(struct page *page,
|
|
struct mm_struct *mm, gfp_t gfp_mask)
|
|
{
|
|
if (mem_cgroup_disabled())
|
|
return 0;
|
|
VM_BUG_ON_PAGE(page_mapped(page), page);
|
|
VM_BUG_ON_PAGE(page->mapping && !PageAnon(page), page);
|
|
VM_BUG_ON(!mm);
|
|
return mem_cgroup_charge_common(page, mm, gfp_mask,
|
|
MEM_CGROUP_CHARGE_TYPE_ANON);
|
|
}
|
|
|
|
/*
|
|
* While swap-in, try_charge -> commit or cancel, the page is locked.
|
|
* And when try_charge() successfully returns, one refcnt to memcg without
|
|
* struct page_cgroup is acquired. This refcnt will be consumed by
|
|
* "commit()" or removed by "cancel()"
|
|
*/
|
|
static int __mem_cgroup_try_charge_swapin(struct mm_struct *mm,
|
|
struct page *page,
|
|
gfp_t mask,
|
|
struct mem_cgroup **memcgp)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
struct page_cgroup *pc;
|
|
int ret;
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
/*
|
|
* Every swap fault against a single page tries to charge the
|
|
* page, bail as early as possible. shmem_unuse() encounters
|
|
* already charged pages, too. The USED bit is protected by
|
|
* the page lock, which serializes swap cache removal, which
|
|
* in turn serializes uncharging.
|
|
*/
|
|
if (PageCgroupUsed(pc))
|
|
return 0;
|
|
if (!do_swap_account)
|
|
goto charge_cur_mm;
|
|
memcg = try_get_mem_cgroup_from_page(page);
|
|
if (!memcg)
|
|
goto charge_cur_mm;
|
|
*memcgp = memcg;
|
|
ret = __mem_cgroup_try_charge(NULL, mask, 1, memcgp, true);
|
|
css_put(&memcg->css);
|
|
if (ret == -EINTR)
|
|
ret = 0;
|
|
return ret;
|
|
charge_cur_mm:
|
|
ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true);
|
|
if (ret == -EINTR)
|
|
ret = 0;
|
|
return ret;
|
|
}
|
|
|
|
int mem_cgroup_try_charge_swapin(struct mm_struct *mm, struct page *page,
|
|
gfp_t gfp_mask, struct mem_cgroup **memcgp)
|
|
{
|
|
*memcgp = NULL;
|
|
if (mem_cgroup_disabled())
|
|
return 0;
|
|
/*
|
|
* A racing thread's fault, or swapoff, may have already
|
|
* updated the pte, and even removed page from swap cache: in
|
|
* those cases unuse_pte()'s pte_same() test will fail; but
|
|
* there's also a KSM case which does need to charge the page.
|
|
*/
|
|
if (!PageSwapCache(page)) {
|
|
int ret;
|
|
|
|
ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, memcgp, true);
|
|
if (ret == -EINTR)
|
|
ret = 0;
|
|
return ret;
|
|
}
|
|
return __mem_cgroup_try_charge_swapin(mm, page, gfp_mask, memcgp);
|
|
}
|
|
|
|
void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg)
|
|
{
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
if (!memcg)
|
|
return;
|
|
__mem_cgroup_cancel_charge(memcg, 1);
|
|
}
|
|
|
|
static void
|
|
__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg,
|
|
enum charge_type ctype)
|
|
{
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
if (!memcg)
|
|
return;
|
|
|
|
__mem_cgroup_commit_charge(memcg, page, 1, ctype, true);
|
|
/*
|
|
* Now swap is on-memory. This means this page may be
|
|
* counted both as mem and swap....double count.
|
|
* Fix it by uncharging from memsw. Basically, this SwapCache is stable
|
|
* under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
|
|
* may call delete_from_swap_cache() before reach here.
|
|
*/
|
|
if (do_swap_account && PageSwapCache(page)) {
|
|
swp_entry_t ent = {.val = page_private(page)};
|
|
mem_cgroup_uncharge_swap(ent);
|
|
}
|
|
}
|
|
|
|
void mem_cgroup_commit_charge_swapin(struct page *page,
|
|
struct mem_cgroup *memcg)
|
|
{
|
|
__mem_cgroup_commit_charge_swapin(page, memcg,
|
|
MEM_CGROUP_CHARGE_TYPE_ANON);
|
|
}
|
|
|
|
int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
|
|
gfp_t gfp_mask)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
|
|
int ret;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return 0;
|
|
if (PageCompound(page))
|
|
return 0;
|
|
|
|
if (!PageSwapCache(page))
|
|
ret = mem_cgroup_charge_common(page, mm, gfp_mask, type);
|
|
else { /* page is swapcache/shmem */
|
|
ret = __mem_cgroup_try_charge_swapin(mm, page,
|
|
gfp_mask, &memcg);
|
|
if (!ret)
|
|
__mem_cgroup_commit_charge_swapin(page, memcg, type);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg,
|
|
unsigned int nr_pages,
|
|
const enum charge_type ctype)
|
|
{
|
|
struct memcg_batch_info *batch = NULL;
|
|
bool uncharge_memsw = true;
|
|
|
|
/* If swapout, usage of swap doesn't decrease */
|
|
if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
|
|
uncharge_memsw = false;
|
|
|
|
batch = ¤t->memcg_batch;
|
|
/*
|
|
* In usual, we do css_get() when we remember memcg pointer.
|
|
* But in this case, we keep res->usage until end of a series of
|
|
* uncharges. Then, it's ok to ignore memcg's refcnt.
|
|
*/
|
|
if (!batch->memcg)
|
|
batch->memcg = memcg;
|
|
/*
|
|
* do_batch > 0 when unmapping pages or inode invalidate/truncate.
|
|
* In those cases, all pages freed continuously can be expected to be in
|
|
* the same cgroup and we have chance to coalesce uncharges.
|
|
* But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
|
|
* because we want to do uncharge as soon as possible.
|
|
*/
|
|
|
|
if (!batch->do_batch || test_thread_flag(TIF_MEMDIE))
|
|
goto direct_uncharge;
|
|
|
|
if (nr_pages > 1)
|
|
goto direct_uncharge;
|
|
|
|
/*
|
|
* In typical case, batch->memcg == mem. This means we can
|
|
* merge a series of uncharges to an uncharge of res_counter.
|
|
* If not, we uncharge res_counter ony by one.
|
|
*/
|
|
if (batch->memcg != memcg)
|
|
goto direct_uncharge;
|
|
/* remember freed charge and uncharge it later */
|
|
batch->nr_pages++;
|
|
if (uncharge_memsw)
|
|
batch->memsw_nr_pages++;
|
|
return;
|
|
direct_uncharge:
|
|
res_counter_uncharge(&memcg->res, nr_pages * PAGE_SIZE);
|
|
if (uncharge_memsw)
|
|
res_counter_uncharge(&memcg->memsw, nr_pages * PAGE_SIZE);
|
|
if (unlikely(batch->memcg != memcg))
|
|
memcg_oom_recover(memcg);
|
|
}
|
|
|
|
/*
|
|
* uncharge if !page_mapped(page)
|
|
*/
|
|
static struct mem_cgroup *
|
|
__mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype,
|
|
bool end_migration)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
unsigned int nr_pages = 1;
|
|
struct page_cgroup *pc;
|
|
bool anon;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return NULL;
|
|
|
|
if (PageTransHuge(page)) {
|
|
nr_pages <<= compound_order(page);
|
|
VM_BUG_ON_PAGE(!PageTransHuge(page), page);
|
|
}
|
|
/*
|
|
* Check if our page_cgroup is valid
|
|
*/
|
|
pc = lookup_page_cgroup(page);
|
|
if (unlikely(!PageCgroupUsed(pc)))
|
|
return NULL;
|
|
|
|
lock_page_cgroup(pc);
|
|
|
|
memcg = pc->mem_cgroup;
|
|
|
|
if (!PageCgroupUsed(pc))
|
|
goto unlock_out;
|
|
|
|
anon = PageAnon(page);
|
|
|
|
switch (ctype) {
|
|
case MEM_CGROUP_CHARGE_TYPE_ANON:
|
|
/*
|
|
* Generally PageAnon tells if it's the anon statistics to be
|
|
* updated; but sometimes e.g. mem_cgroup_uncharge_page() is
|
|
* used before page reached the stage of being marked PageAnon.
|
|
*/
|
|
anon = true;
|
|
/* fallthrough */
|
|
case MEM_CGROUP_CHARGE_TYPE_DROP:
|
|
/* See mem_cgroup_prepare_migration() */
|
|
if (page_mapped(page))
|
|
goto unlock_out;
|
|
/*
|
|
* Pages under migration may not be uncharged. But
|
|
* end_migration() /must/ be the one uncharging the
|
|
* unused post-migration page and so it has to call
|
|
* here with the migration bit still set. See the
|
|
* res_counter handling below.
|
|
*/
|
|
if (!end_migration && PageCgroupMigration(pc))
|
|
goto unlock_out;
|
|
break;
|
|
case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
|
|
if (!PageAnon(page)) { /* Shared memory */
|
|
if (page->mapping && !page_is_file_cache(page))
|
|
goto unlock_out;
|
|
} else if (page_mapped(page)) /* Anon */
|
|
goto unlock_out;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
mem_cgroup_charge_statistics(memcg, page, anon, -nr_pages);
|
|
|
|
ClearPageCgroupUsed(pc);
|
|
/*
|
|
* pc->mem_cgroup is not cleared here. It will be accessed when it's
|
|
* freed from LRU. This is safe because uncharged page is expected not
|
|
* to be reused (freed soon). Exception is SwapCache, it's handled by
|
|
* special functions.
|
|
*/
|
|
|
|
unlock_page_cgroup(pc);
|
|
/*
|
|
* even after unlock, we have memcg->res.usage here and this memcg
|
|
* will never be freed, so it's safe to call css_get().
|
|
*/
|
|
memcg_check_events(memcg, page);
|
|
if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) {
|
|
mem_cgroup_swap_statistics(memcg, true);
|
|
css_get(&memcg->css);
|
|
}
|
|
/*
|
|
* Migration does not charge the res_counter for the
|
|
* replacement page, so leave it alone when phasing out the
|
|
* page that is unused after the migration.
|
|
*/
|
|
if (!end_migration && !mem_cgroup_is_root(memcg))
|
|
mem_cgroup_do_uncharge(memcg, nr_pages, ctype);
|
|
|
|
return memcg;
|
|
|
|
unlock_out:
|
|
unlock_page_cgroup(pc);
|
|
return NULL;
|
|
}
|
|
|
|
void mem_cgroup_uncharge_page(struct page *page)
|
|
{
|
|
/* early check. */
|
|
if (page_mapped(page))
|
|
return;
|
|
VM_BUG_ON_PAGE(page->mapping && !PageAnon(page), page);
|
|
/*
|
|
* If the page is in swap cache, uncharge should be deferred
|
|
* to the swap path, which also properly accounts swap usage
|
|
* and handles memcg lifetime.
|
|
*
|
|
* Note that this check is not stable and reclaim may add the
|
|
* page to swap cache at any time after this. However, if the
|
|
* page is not in swap cache by the time page->mapcount hits
|
|
* 0, there won't be any page table references to the swap
|
|
* slot, and reclaim will free it and not actually write the
|
|
* page to disk.
|
|
*/
|
|
if (PageSwapCache(page))
|
|
return;
|
|
__mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_ANON, false);
|
|
}
|
|
|
|
void mem_cgroup_uncharge_cache_page(struct page *page)
|
|
{
|
|
VM_BUG_ON_PAGE(page_mapped(page), page);
|
|
VM_BUG_ON_PAGE(page->mapping, page);
|
|
__mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE, false);
|
|
}
|
|
|
|
/*
|
|
* Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
|
|
* In that cases, pages are freed continuously and we can expect pages
|
|
* are in the same memcg. All these calls itself limits the number of
|
|
* pages freed at once, then uncharge_start/end() is called properly.
|
|
* This may be called prural(2) times in a context,
|
|
*/
|
|
|
|
void mem_cgroup_uncharge_start(void)
|
|
{
|
|
current->memcg_batch.do_batch++;
|
|
/* We can do nest. */
|
|
if (current->memcg_batch.do_batch == 1) {
|
|
current->memcg_batch.memcg = NULL;
|
|
current->memcg_batch.nr_pages = 0;
|
|
current->memcg_batch.memsw_nr_pages = 0;
|
|
}
|
|
}
|
|
|
|
void mem_cgroup_uncharge_end(void)
|
|
{
|
|
struct memcg_batch_info *batch = ¤t->memcg_batch;
|
|
|
|
if (!batch->do_batch)
|
|
return;
|
|
|
|
batch->do_batch--;
|
|
if (batch->do_batch) /* If stacked, do nothing. */
|
|
return;
|
|
|
|
if (!batch->memcg)
|
|
return;
|
|
/*
|
|
* This "batch->memcg" is valid without any css_get/put etc...
|
|
* bacause we hide charges behind us.
|
|
*/
|
|
if (batch->nr_pages)
|
|
res_counter_uncharge(&batch->memcg->res,
|
|
batch->nr_pages * PAGE_SIZE);
|
|
if (batch->memsw_nr_pages)
|
|
res_counter_uncharge(&batch->memcg->memsw,
|
|
batch->memsw_nr_pages * PAGE_SIZE);
|
|
memcg_oom_recover(batch->memcg);
|
|
/* forget this pointer (for sanity check) */
|
|
batch->memcg = NULL;
|
|
}
|
|
|
|
#ifdef CONFIG_SWAP
|
|
/*
|
|
* called after __delete_from_swap_cache() and drop "page" account.
|
|
* memcg information is recorded to swap_cgroup of "ent"
|
|
*/
|
|
void
|
|
mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT;
|
|
|
|
if (!swapout) /* this was a swap cache but the swap is unused ! */
|
|
ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
|
|
|
|
memcg = __mem_cgroup_uncharge_common(page, ctype, false);
|
|
|
|
/*
|
|
* record memcg information, if swapout && memcg != NULL,
|
|
* css_get() was called in uncharge().
|
|
*/
|
|
if (do_swap_account && swapout && memcg)
|
|
swap_cgroup_record(ent, mem_cgroup_id(memcg));
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_MEMCG_SWAP
|
|
/*
|
|
* called from swap_entry_free(). remove record in swap_cgroup and
|
|
* uncharge "memsw" account.
|
|
*/
|
|
void mem_cgroup_uncharge_swap(swp_entry_t ent)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
unsigned short id;
|
|
|
|
if (!do_swap_account)
|
|
return;
|
|
|
|
id = swap_cgroup_record(ent, 0);
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_lookup(id);
|
|
if (memcg) {
|
|
/*
|
|
* We uncharge this because swap is freed.
|
|
* This memcg can be obsolete one. We avoid calling css_tryget
|
|
*/
|
|
if (!mem_cgroup_is_root(memcg))
|
|
res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
|
|
mem_cgroup_swap_statistics(memcg, false);
|
|
css_put(&memcg->css);
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
|
|
* @entry: swap entry to be moved
|
|
* @from: mem_cgroup which the entry is moved from
|
|
* @to: mem_cgroup which the entry is moved to
|
|
*
|
|
* It succeeds only when the swap_cgroup's record for this entry is the same
|
|
* as the mem_cgroup's id of @from.
|
|
*
|
|
* Returns 0 on success, -EINVAL on failure.
|
|
*
|
|
* The caller must have charged to @to, IOW, called res_counter_charge() about
|
|
* both res and memsw, and called css_get().
|
|
*/
|
|
static int mem_cgroup_move_swap_account(swp_entry_t entry,
|
|
struct mem_cgroup *from, struct mem_cgroup *to)
|
|
{
|
|
unsigned short old_id, new_id;
|
|
|
|
old_id = mem_cgroup_id(from);
|
|
new_id = mem_cgroup_id(to);
|
|
|
|
if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
|
|
mem_cgroup_swap_statistics(from, false);
|
|
mem_cgroup_swap_statistics(to, true);
|
|
/*
|
|
* This function is only called from task migration context now.
|
|
* It postpones res_counter and refcount handling till the end
|
|
* of task migration(mem_cgroup_clear_mc()) for performance
|
|
* improvement. But we cannot postpone css_get(to) because if
|
|
* the process that has been moved to @to does swap-in, the
|
|
* refcount of @to might be decreased to 0.
|
|
*
|
|
* We are in attach() phase, so the cgroup is guaranteed to be
|
|
* alive, so we can just call css_get().
|
|
*/
|
|
css_get(&to->css);
|
|
return 0;
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
#else
|
|
static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
|
|
struct mem_cgroup *from, struct mem_cgroup *to)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Before starting migration, account PAGE_SIZE to mem_cgroup that the old
|
|
* page belongs to.
|
|
*/
|
|
void mem_cgroup_prepare_migration(struct page *page, struct page *newpage,
|
|
struct mem_cgroup **memcgp)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
unsigned int nr_pages = 1;
|
|
struct page_cgroup *pc;
|
|
enum charge_type ctype;
|
|
|
|
*memcgp = NULL;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
if (PageTransHuge(page))
|
|
nr_pages <<= compound_order(page);
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
lock_page_cgroup(pc);
|
|
if (PageCgroupUsed(pc)) {
|
|
memcg = pc->mem_cgroup;
|
|
css_get(&memcg->css);
|
|
/*
|
|
* At migrating an anonymous page, its mapcount goes down
|
|
* to 0 and uncharge() will be called. But, even if it's fully
|
|
* unmapped, migration may fail and this page has to be
|
|
* charged again. We set MIGRATION flag here and delay uncharge
|
|
* until end_migration() is called
|
|
*
|
|
* Corner Case Thinking
|
|
* A)
|
|
* When the old page was mapped as Anon and it's unmap-and-freed
|
|
* while migration was ongoing.
|
|
* If unmap finds the old page, uncharge() of it will be delayed
|
|
* until end_migration(). If unmap finds a new page, it's
|
|
* uncharged when it make mapcount to be 1->0. If unmap code
|
|
* finds swap_migration_entry, the new page will not be mapped
|
|
* and end_migration() will find it(mapcount==0).
|
|
*
|
|
* B)
|
|
* When the old page was mapped but migraion fails, the kernel
|
|
* remaps it. A charge for it is kept by MIGRATION flag even
|
|
* if mapcount goes down to 0. We can do remap successfully
|
|
* without charging it again.
|
|
*
|
|
* C)
|
|
* The "old" page is under lock_page() until the end of
|
|
* migration, so, the old page itself will not be swapped-out.
|
|
* If the new page is swapped out before end_migraton, our
|
|
* hook to usual swap-out path will catch the event.
|
|
*/
|
|
if (PageAnon(page))
|
|
SetPageCgroupMigration(pc);
|
|
}
|
|
unlock_page_cgroup(pc);
|
|
/*
|
|
* If the page is not charged at this point,
|
|
* we return here.
|
|
*/
|
|
if (!memcg)
|
|
return;
|
|
|
|
*memcgp = memcg;
|
|
/*
|
|
* We charge new page before it's used/mapped. So, even if unlock_page()
|
|
* is called before end_migration, we can catch all events on this new
|
|
* page. In the case new page is migrated but not remapped, new page's
|
|
* mapcount will be finally 0 and we call uncharge in end_migration().
|
|
*/
|
|
if (PageAnon(page))
|
|
ctype = MEM_CGROUP_CHARGE_TYPE_ANON;
|
|
else
|
|
ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
|
|
/*
|
|
* The page is committed to the memcg, but it's not actually
|
|
* charged to the res_counter since we plan on replacing the
|
|
* old one and only one page is going to be left afterwards.
|
|
*/
|
|
__mem_cgroup_commit_charge(memcg, newpage, nr_pages, ctype, false);
|
|
}
|
|
|
|
/* remove redundant charge if migration failed*/
|
|
void mem_cgroup_end_migration(struct mem_cgroup *memcg,
|
|
struct page *oldpage, struct page *newpage, bool migration_ok)
|
|
{
|
|
struct page *used, *unused;
|
|
struct page_cgroup *pc;
|
|
bool anon;
|
|
|
|
if (!memcg)
|
|
return;
|
|
|
|
if (!migration_ok) {
|
|
used = oldpage;
|
|
unused = newpage;
|
|
} else {
|
|
used = newpage;
|
|
unused = oldpage;
|
|
}
|
|
anon = PageAnon(used);
|
|
__mem_cgroup_uncharge_common(unused,
|
|
anon ? MEM_CGROUP_CHARGE_TYPE_ANON
|
|
: MEM_CGROUP_CHARGE_TYPE_CACHE,
|
|
true);
|
|
css_put(&memcg->css);
|
|
/*
|
|
* We disallowed uncharge of pages under migration because mapcount
|
|
* of the page goes down to zero, temporarly.
|
|
* Clear the flag and check the page should be charged.
|
|
*/
|
|
pc = lookup_page_cgroup(oldpage);
|
|
lock_page_cgroup(pc);
|
|
ClearPageCgroupMigration(pc);
|
|
unlock_page_cgroup(pc);
|
|
|
|
/*
|
|
* If a page is a file cache, radix-tree replacement is very atomic
|
|
* and we can skip this check. When it was an Anon page, its mapcount
|
|
* goes down to 0. But because we added MIGRATION flage, it's not
|
|
* uncharged yet. There are several case but page->mapcount check
|
|
* and USED bit check in mem_cgroup_uncharge_page() will do enough
|
|
* check. (see prepare_charge() also)
|
|
*/
|
|
if (anon)
|
|
mem_cgroup_uncharge_page(used);
|
|
}
|
|
|
|
/*
|
|
* At replace page cache, newpage is not under any memcg but it's on
|
|
* LRU. So, this function doesn't touch res_counter but handles LRU
|
|
* in correct way. Both pages are locked so we cannot race with uncharge.
|
|
*/
|
|
void mem_cgroup_replace_page_cache(struct page *oldpage,
|
|
struct page *newpage)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
struct page_cgroup *pc;
|
|
enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
pc = lookup_page_cgroup(oldpage);
|
|
/* fix accounting on old pages */
|
|
lock_page_cgroup(pc);
|
|
if (PageCgroupUsed(pc)) {
|
|
memcg = pc->mem_cgroup;
|
|
mem_cgroup_charge_statistics(memcg, oldpage, false, -1);
|
|
ClearPageCgroupUsed(pc);
|
|
}
|
|
unlock_page_cgroup(pc);
|
|
|
|
/*
|
|
* When called from shmem_replace_page(), in some cases the
|
|
* oldpage has already been charged, and in some cases not.
|
|
*/
|
|
if (!memcg)
|
|
return;
|
|
/*
|
|
* Even if newpage->mapping was NULL before starting replacement,
|
|
* the newpage may be on LRU(or pagevec for LRU) already. We lock
|
|
* LRU while we overwrite pc->mem_cgroup.
|
|
*/
|
|
__mem_cgroup_commit_charge(memcg, newpage, 1, type, true);
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_VM
|
|
static struct page_cgroup *lookup_page_cgroup_used(struct page *page)
|
|
{
|
|
struct page_cgroup *pc;
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
/*
|
|
* Can be NULL while feeding pages into the page allocator for
|
|
* the first time, i.e. during boot or memory hotplug;
|
|
* or when mem_cgroup_disabled().
|
|
*/
|
|
if (likely(pc) && PageCgroupUsed(pc))
|
|
return pc;
|
|
return NULL;
|
|
}
|
|
|
|
bool mem_cgroup_bad_page_check(struct page *page)
|
|
{
|
|
if (mem_cgroup_disabled())
|
|
return false;
|
|
|
|
return lookup_page_cgroup_used(page) != NULL;
|
|
}
|
|
|
|
void mem_cgroup_print_bad_page(struct page *page)
|
|
{
|
|
struct page_cgroup *pc;
|
|
|
|
pc = lookup_page_cgroup_used(page);
|
|
if (pc) {
|
|
pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
|
|
pc, pc->flags, pc->mem_cgroup);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
|
|
unsigned long long val)
|
|
{
|
|
int retry_count;
|
|
u64 memswlimit, memlimit;
|
|
int ret = 0;
|
|
int children = mem_cgroup_count_children(memcg);
|
|
u64 curusage, oldusage;
|
|
int enlarge;
|
|
|
|
/*
|
|
* For keeping hierarchical_reclaim simple, how long we should retry
|
|
* is depends on callers. We set our retry-count to be function
|
|
* of # of children which we should visit in this loop.
|
|
*/
|
|
retry_count = MEM_CGROUP_RECLAIM_RETRIES * children;
|
|
|
|
oldusage = res_counter_read_u64(&memcg->res, RES_USAGE);
|
|
|
|
enlarge = 0;
|
|
while (retry_count) {
|
|
if (signal_pending(current)) {
|
|
ret = -EINTR;
|
|
break;
|
|
}
|
|
/*
|
|
* Rather than hide all in some function, I do this in
|
|
* open coded manner. You see what this really does.
|
|
* We have to guarantee memcg->res.limit <= memcg->memsw.limit.
|
|
*/
|
|
mutex_lock(&set_limit_mutex);
|
|
memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
|
|
if (memswlimit < val) {
|
|
ret = -EINVAL;
|
|
mutex_unlock(&set_limit_mutex);
|
|
break;
|
|
}
|
|
|
|
memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
|
|
if (memlimit < val)
|
|
enlarge = 1;
|
|
|
|
ret = res_counter_set_limit(&memcg->res, val);
|
|
if (!ret) {
|
|
if (memswlimit == val)
|
|
memcg->memsw_is_minimum = true;
|
|
else
|
|
memcg->memsw_is_minimum = false;
|
|
}
|
|
mutex_unlock(&set_limit_mutex);
|
|
|
|
if (!ret)
|
|
break;
|
|
|
|
mem_cgroup_reclaim(memcg, GFP_KERNEL,
|
|
MEM_CGROUP_RECLAIM_SHRINK);
|
|
curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
|
|
/* Usage is reduced ? */
|
|
if (curusage >= oldusage)
|
|
retry_count--;
|
|
else
|
|
oldusage = curusage;
|
|
}
|
|
if (!ret && enlarge)
|
|
memcg_oom_recover(memcg);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
|
|
unsigned long long val)
|
|
{
|
|
int retry_count;
|
|
u64 memlimit, memswlimit, oldusage, curusage;
|
|
int children = mem_cgroup_count_children(memcg);
|
|
int ret = -EBUSY;
|
|
int enlarge = 0;
|
|
|
|
/* see mem_cgroup_resize_res_limit */
|
|
retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
|
|
oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
|
|
while (retry_count) {
|
|
if (signal_pending(current)) {
|
|
ret = -EINTR;
|
|
break;
|
|
}
|
|
/*
|
|
* Rather than hide all in some function, I do this in
|
|
* open coded manner. You see what this really does.
|
|
* We have to guarantee memcg->res.limit <= memcg->memsw.limit.
|
|
*/
|
|
mutex_lock(&set_limit_mutex);
|
|
memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
|
|
if (memlimit > val) {
|
|
ret = -EINVAL;
|
|
mutex_unlock(&set_limit_mutex);
|
|
break;
|
|
}
|
|
memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
|
|
if (memswlimit < val)
|
|
enlarge = 1;
|
|
ret = res_counter_set_limit(&memcg->memsw, val);
|
|
if (!ret) {
|
|
if (memlimit == val)
|
|
memcg->memsw_is_minimum = true;
|
|
else
|
|
memcg->memsw_is_minimum = false;
|
|
}
|
|
mutex_unlock(&set_limit_mutex);
|
|
|
|
if (!ret)
|
|
break;
|
|
|
|
mem_cgroup_reclaim(memcg, GFP_KERNEL,
|
|
MEM_CGROUP_RECLAIM_NOSWAP |
|
|
MEM_CGROUP_RECLAIM_SHRINK);
|
|
curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
|
|
/* Usage is reduced ? */
|
|
if (curusage >= oldusage)
|
|
retry_count--;
|
|
else
|
|
oldusage = curusage;
|
|
}
|
|
if (!ret && enlarge)
|
|
memcg_oom_recover(memcg);
|
|
return ret;
|
|
}
|
|
|
|
unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
|
|
gfp_t gfp_mask,
|
|
unsigned long *total_scanned)
|
|
{
|
|
unsigned long nr_reclaimed = 0;
|
|
struct mem_cgroup_per_zone *mz, *next_mz = NULL;
|
|
unsigned long reclaimed;
|
|
int loop = 0;
|
|
struct mem_cgroup_tree_per_zone *mctz;
|
|
unsigned long long excess;
|
|
unsigned long nr_scanned;
|
|
|
|
if (order > 0)
|
|
return 0;
|
|
|
|
mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone));
|
|
/*
|
|
* This loop can run a while, specially if mem_cgroup's continuously
|
|
* keep exceeding their soft limit and putting the system under
|
|
* pressure
|
|
*/
|
|
do {
|
|
if (next_mz)
|
|
mz = next_mz;
|
|
else
|
|
mz = mem_cgroup_largest_soft_limit_node(mctz);
|
|
if (!mz)
|
|
break;
|
|
|
|
nr_scanned = 0;
|
|
reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone,
|
|
gfp_mask, &nr_scanned);
|
|
nr_reclaimed += reclaimed;
|
|
*total_scanned += nr_scanned;
|
|
spin_lock(&mctz->lock);
|
|
|
|
/*
|
|
* If we failed to reclaim anything from this memory cgroup
|
|
* it is time to move on to the next cgroup
|
|
*/
|
|
next_mz = NULL;
|
|
if (!reclaimed) {
|
|
do {
|
|
/*
|
|
* Loop until we find yet another one.
|
|
*
|
|
* By the time we get the soft_limit lock
|
|
* again, someone might have aded the
|
|
* group back on the RB tree. Iterate to
|
|
* make sure we get a different mem.
|
|
* mem_cgroup_largest_soft_limit_node returns
|
|
* NULL if no other cgroup is present on
|
|
* the tree
|
|
*/
|
|
next_mz =
|
|
__mem_cgroup_largest_soft_limit_node(mctz);
|
|
if (next_mz == mz)
|
|
css_put(&next_mz->memcg->css);
|
|
else /* next_mz == NULL or other memcg */
|
|
break;
|
|
} while (1);
|
|
}
|
|
__mem_cgroup_remove_exceeded(mz->memcg, mz, mctz);
|
|
excess = res_counter_soft_limit_excess(&mz->memcg->res);
|
|
/*
|
|
* One school of thought says that we should not add
|
|
* back the node to the tree if reclaim returns 0.
|
|
* But our reclaim could return 0, simply because due
|
|
* to priority we are exposing a smaller subset of
|
|
* memory to reclaim from. Consider this as a longer
|
|
* term TODO.
|
|
*/
|
|
/* If excess == 0, no tree ops */
|
|
__mem_cgroup_insert_exceeded(mz->memcg, mz, mctz, excess);
|
|
spin_unlock(&mctz->lock);
|
|
css_put(&mz->memcg->css);
|
|
loop++;
|
|
/*
|
|
* Could not reclaim anything and there are no more
|
|
* mem cgroups to try or we seem to be looping without
|
|
* reclaiming anything.
|
|
*/
|
|
if (!nr_reclaimed &&
|
|
(next_mz == NULL ||
|
|
loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
|
|
break;
|
|
} while (!nr_reclaimed);
|
|
if (next_mz)
|
|
css_put(&next_mz->memcg->css);
|
|
return nr_reclaimed;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_force_empty_list - clears LRU of a group
|
|
* @memcg: group to clear
|
|
* @node: NUMA node
|
|
* @zid: zone id
|
|
* @lru: lru to to clear
|
|
*
|
|
* Traverse a specified page_cgroup list and try to drop them all. This doesn't
|
|
* reclaim the pages page themselves - pages are moved to the parent (or root)
|
|
* group.
|
|
*/
|
|
static void mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
|
|
int node, int zid, enum lru_list lru)
|
|
{
|
|
struct lruvec *lruvec;
|
|
unsigned long flags;
|
|
struct list_head *list;
|
|
struct page *busy;
|
|
struct zone *zone;
|
|
|
|
zone = &NODE_DATA(node)->node_zones[zid];
|
|
lruvec = mem_cgroup_zone_lruvec(zone, memcg);
|
|
list = &lruvec->lists[lru];
|
|
|
|
busy = NULL;
|
|
do {
|
|
struct page_cgroup *pc;
|
|
struct page *page;
|
|
|
|
spin_lock_irqsave(&zone->lru_lock, flags);
|
|
if (list_empty(list)) {
|
|
spin_unlock_irqrestore(&zone->lru_lock, flags);
|
|
break;
|
|
}
|
|
page = list_entry(list->prev, struct page, lru);
|
|
if (busy == page) {
|
|
list_move(&page->lru, list);
|
|
busy = NULL;
|
|
spin_unlock_irqrestore(&zone->lru_lock, flags);
|
|
continue;
|
|
}
|
|
spin_unlock_irqrestore(&zone->lru_lock, flags);
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
|
|
if (mem_cgroup_move_parent(page, pc, memcg)) {
|
|
/* found lock contention or "pc" is obsolete. */
|
|
busy = page;
|
|
cond_resched();
|
|
} else
|
|
busy = NULL;
|
|
} while (!list_empty(list));
|
|
}
|
|
|
|
/*
|
|
* make mem_cgroup's charge to be 0 if there is no task by moving
|
|
* all the charges and pages to the parent.
|
|
* This enables deleting this mem_cgroup.
|
|
*
|
|
* Caller is responsible for holding css reference on the memcg.
|
|
*/
|
|
static void mem_cgroup_reparent_charges(struct mem_cgroup *memcg)
|
|
{
|
|
int node, zid;
|
|
u64 usage;
|
|
|
|
do {
|
|
/* This is for making all *used* pages to be on LRU. */
|
|
lru_add_drain_all();
|
|
drain_all_stock_sync(memcg);
|
|
mem_cgroup_start_move(memcg);
|
|
for_each_node_state(node, N_MEMORY) {
|
|
for (zid = 0; zid < MAX_NR_ZONES; zid++) {
|
|
enum lru_list lru;
|
|
for_each_lru(lru) {
|
|
mem_cgroup_force_empty_list(memcg,
|
|
node, zid, lru);
|
|
}
|
|
}
|
|
}
|
|
mem_cgroup_end_move(memcg);
|
|
memcg_oom_recover(memcg);
|
|
cond_resched();
|
|
|
|
/*
|
|
* Kernel memory may not necessarily be trackable to a specific
|
|
* process. So they are not migrated, and therefore we can't
|
|
* expect their value to drop to 0 here.
|
|
* Having res filled up with kmem only is enough.
|
|
*
|
|
* This is a safety check because mem_cgroup_force_empty_list
|
|
* could have raced with mem_cgroup_replace_page_cache callers
|
|
* so the lru seemed empty but the page could have been added
|
|
* right after the check. RES_USAGE should be safe as we always
|
|
* charge before adding to the LRU.
|
|
*/
|
|
usage = res_counter_read_u64(&memcg->res, RES_USAGE) -
|
|
res_counter_read_u64(&memcg->kmem, RES_USAGE);
|
|
} while (usage > 0);
|
|
}
|
|
|
|
static inline bool memcg_has_children(struct mem_cgroup *memcg)
|
|
{
|
|
lockdep_assert_held(&memcg_create_mutex);
|
|
/*
|
|
* The lock does not prevent addition or deletion to the list
|
|
* of children, but it prevents a new child from being
|
|
* initialized based on this parent in css_online(), so it's
|
|
* enough to decide whether hierarchically inherited
|
|
* attributes can still be changed or not.
|
|
*/
|
|
return memcg->use_hierarchy &&
|
|
!list_empty(&memcg->css.cgroup->children);
|
|
}
|
|
|
|
/*
|
|
* Reclaims as many pages from the given memcg as possible and moves
|
|
* the rest to the parent.
|
|
*
|
|
* Caller is responsible for holding css reference for memcg.
|
|
*/
|
|
static int mem_cgroup_force_empty(struct mem_cgroup *memcg)
|
|
{
|
|
int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
|
|
struct cgroup *cgrp = memcg->css.cgroup;
|
|
|
|
/* returns EBUSY if there is a task or if we come here twice. */
|
|
if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
|
|
return -EBUSY;
|
|
|
|
/* we call try-to-free pages for make this cgroup empty */
|
|
lru_add_drain_all();
|
|
/* try to free all pages in this cgroup */
|
|
while (nr_retries && res_counter_read_u64(&memcg->res, RES_USAGE) > 0) {
|
|
int progress;
|
|
|
|
if (signal_pending(current))
|
|
return -EINTR;
|
|
|
|
progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL,
|
|
false);
|
|
if (!progress) {
|
|
nr_retries--;
|
|
/* maybe some writeback is necessary */
|
|
congestion_wait(BLK_RW_ASYNC, HZ/10);
|
|
}
|
|
|
|
}
|
|
lru_add_drain();
|
|
mem_cgroup_reparent_charges(memcg);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mem_cgroup_force_empty_write(struct cgroup_subsys_state *css,
|
|
unsigned int event)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
if (mem_cgroup_is_root(memcg))
|
|
return -EINVAL;
|
|
return mem_cgroup_force_empty(memcg);
|
|
}
|
|
|
|
static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
return mem_cgroup_from_css(css)->use_hierarchy;
|
|
}
|
|
|
|
static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
int retval = 0;
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup *parent_memcg = mem_cgroup_from_css(css_parent(&memcg->css));
|
|
|
|
mutex_lock(&memcg_create_mutex);
|
|
|
|
if (memcg->use_hierarchy == val)
|
|
goto out;
|
|
|
|
/*
|
|
* If parent's use_hierarchy is set, we can't make any modifications
|
|
* in the child subtrees. If it is unset, then the change can
|
|
* occur, provided the current cgroup has no children.
|
|
*
|
|
* For the root cgroup, parent_mem is NULL, we allow value to be
|
|
* set if there are no children.
|
|
*/
|
|
if ((!parent_memcg || !parent_memcg->use_hierarchy) &&
|
|
(val == 1 || val == 0)) {
|
|
if (list_empty(&memcg->css.cgroup->children))
|
|
memcg->use_hierarchy = val;
|
|
else
|
|
retval = -EBUSY;
|
|
} else
|
|
retval = -EINVAL;
|
|
|
|
out:
|
|
mutex_unlock(&memcg_create_mutex);
|
|
|
|
return retval;
|
|
}
|
|
|
|
|
|
static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg,
|
|
enum mem_cgroup_stat_index idx)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
long val = 0;
|
|
|
|
/* Per-cpu values can be negative, use a signed accumulator */
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
val += mem_cgroup_read_stat(iter, idx);
|
|
|
|
if (val < 0) /* race ? */
|
|
val = 0;
|
|
return val;
|
|
}
|
|
|
|
static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
|
|
{
|
|
u64 val;
|
|
|
|
if (!mem_cgroup_is_root(memcg)) {
|
|
if (!swap)
|
|
return res_counter_read_u64(&memcg->res, RES_USAGE);
|
|
else
|
|
return res_counter_read_u64(&memcg->memsw, RES_USAGE);
|
|
}
|
|
|
|
/*
|
|
* Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
|
|
* as well as in MEM_CGROUP_STAT_RSS_HUGE.
|
|
*/
|
|
val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE);
|
|
val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS);
|
|
|
|
if (swap)
|
|
val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAP);
|
|
|
|
return val << PAGE_SHIFT;
|
|
}
|
|
|
|
static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
u64 val;
|
|
int name;
|
|
enum res_type type;
|
|
|
|
type = MEMFILE_TYPE(cft->private);
|
|
name = MEMFILE_ATTR(cft->private);
|
|
|
|
switch (type) {
|
|
case _MEM:
|
|
if (name == RES_USAGE)
|
|
val = mem_cgroup_usage(memcg, false);
|
|
else
|
|
val = res_counter_read_u64(&memcg->res, name);
|
|
break;
|
|
case _MEMSWAP:
|
|
if (name == RES_USAGE)
|
|
val = mem_cgroup_usage(memcg, true);
|
|
else
|
|
val = res_counter_read_u64(&memcg->memsw, name);
|
|
break;
|
|
case _KMEM:
|
|
val = res_counter_read_u64(&memcg->kmem, name);
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
return val;
|
|
}
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
/* should be called with activate_kmem_mutex held */
|
|
static int __memcg_activate_kmem(struct mem_cgroup *memcg,
|
|
unsigned long long limit)
|
|
{
|
|
int err = 0;
|
|
int memcg_id;
|
|
|
|
if (memcg_kmem_is_active(memcg))
|
|
return 0;
|
|
|
|
/*
|
|
* We are going to allocate memory for data shared by all memory
|
|
* cgroups so let's stop accounting here.
|
|
*/
|
|
memcg_stop_kmem_account();
|
|
|
|
/*
|
|
* For simplicity, we won't allow this to be disabled. It also can't
|
|
* be changed if the cgroup has children already, or if tasks had
|
|
* already joined.
|
|
*
|
|
* If tasks join before we set the limit, a person looking at
|
|
* kmem.usage_in_bytes will have no way to determine when it took
|
|
* place, which makes the value quite meaningless.
|
|
*
|
|
* After it first became limited, changes in the value of the limit are
|
|
* of course permitted.
|
|
*/
|
|
mutex_lock(&memcg_create_mutex);
|
|
if (cgroup_task_count(memcg->css.cgroup) || memcg_has_children(memcg))
|
|
err = -EBUSY;
|
|
mutex_unlock(&memcg_create_mutex);
|
|
if (err)
|
|
goto out;
|
|
|
|
memcg_id = ida_simple_get(&kmem_limited_groups,
|
|
0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL);
|
|
if (memcg_id < 0) {
|
|
err = memcg_id;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Make sure we have enough space for this cgroup in each root cache's
|
|
* memcg_params.
|
|
*/
|
|
err = memcg_update_all_caches(memcg_id + 1);
|
|
if (err)
|
|
goto out_rmid;
|
|
|
|
memcg->kmemcg_id = memcg_id;
|
|
INIT_LIST_HEAD(&memcg->memcg_slab_caches);
|
|
mutex_init(&memcg->slab_caches_mutex);
|
|
|
|
/*
|
|
* We couldn't have accounted to this cgroup, because it hasn't got the
|
|
* active bit set yet, so this should succeed.
|
|
*/
|
|
err = res_counter_set_limit(&memcg->kmem, limit);
|
|
VM_BUG_ON(err);
|
|
|
|
static_key_slow_inc(&memcg_kmem_enabled_key);
|
|
/*
|
|
* Setting the active bit after enabling static branching will
|
|
* guarantee no one starts accounting before all call sites are
|
|
* patched.
|
|
*/
|
|
memcg_kmem_set_active(memcg);
|
|
out:
|
|
memcg_resume_kmem_account();
|
|
return err;
|
|
|
|
out_rmid:
|
|
ida_simple_remove(&kmem_limited_groups, memcg_id);
|
|
goto out;
|
|
}
|
|
|
|
static int memcg_activate_kmem(struct mem_cgroup *memcg,
|
|
unsigned long long limit)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&activate_kmem_mutex);
|
|
ret = __memcg_activate_kmem(memcg, limit);
|
|
mutex_unlock(&activate_kmem_mutex);
|
|
return ret;
|
|
}
|
|
|
|
static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
|
|
unsigned long long val)
|
|
{
|
|
int ret;
|
|
|
|
if (!memcg_kmem_is_active(memcg))
|
|
ret = memcg_activate_kmem(memcg, val);
|
|
else
|
|
ret = res_counter_set_limit(&memcg->kmem, val);
|
|
return ret;
|
|
}
|
|
|
|
static int memcg_propagate_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
int ret = 0;
|
|
struct mem_cgroup *parent = parent_mem_cgroup(memcg);
|
|
|
|
if (!parent)
|
|
return 0;
|
|
|
|
mutex_lock(&activate_kmem_mutex);
|
|
/*
|
|
* If the parent cgroup is not kmem-active now, it cannot be activated
|
|
* after this point, because it has at least one child already.
|
|
*/
|
|
if (memcg_kmem_is_active(parent))
|
|
ret = __memcg_activate_kmem(memcg, RES_COUNTER_MAX);
|
|
mutex_unlock(&activate_kmem_mutex);
|
|
return ret;
|
|
}
|
|
#else
|
|
static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
|
|
unsigned long long val)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
#endif /* CONFIG_MEMCG_KMEM */
|
|
|
|
/*
|
|
* The user of this function is...
|
|
* RES_LIMIT.
|
|
*/
|
|
static int mem_cgroup_write(struct cgroup_subsys_state *css, struct cftype *cft,
|
|
const char *buffer)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
enum res_type type;
|
|
int name;
|
|
unsigned long long val;
|
|
int ret;
|
|
|
|
type = MEMFILE_TYPE(cft->private);
|
|
name = MEMFILE_ATTR(cft->private);
|
|
|
|
switch (name) {
|
|
case RES_LIMIT:
|
|
if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
/* This function does all necessary parse...reuse it */
|
|
ret = res_counter_memparse_write_strategy(buffer, &val);
|
|
if (ret)
|
|
break;
|
|
if (type == _MEM)
|
|
ret = mem_cgroup_resize_limit(memcg, val);
|
|
else if (type == _MEMSWAP)
|
|
ret = mem_cgroup_resize_memsw_limit(memcg, val);
|
|
else if (type == _KMEM)
|
|
ret = memcg_update_kmem_limit(memcg, val);
|
|
else
|
|
return -EINVAL;
|
|
break;
|
|
case RES_SOFT_LIMIT:
|
|
ret = res_counter_memparse_write_strategy(buffer, &val);
|
|
if (ret)
|
|
break;
|
|
/*
|
|
* For memsw, soft limits are hard to implement in terms
|
|
* of semantics, for now, we support soft limits for
|
|
* control without swap
|
|
*/
|
|
if (type == _MEM)
|
|
ret = res_counter_set_soft_limit(&memcg->res, val);
|
|
else
|
|
ret = -EINVAL;
|
|
break;
|
|
default:
|
|
ret = -EINVAL; /* should be BUG() ? */
|
|
break;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
|
|
unsigned long long *mem_limit, unsigned long long *memsw_limit)
|
|
{
|
|
unsigned long long min_limit, min_memsw_limit, tmp;
|
|
|
|
min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
|
|
min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
|
|
if (!memcg->use_hierarchy)
|
|
goto out;
|
|
|
|
while (css_parent(&memcg->css)) {
|
|
memcg = mem_cgroup_from_css(css_parent(&memcg->css));
|
|
if (!memcg->use_hierarchy)
|
|
break;
|
|
tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
|
|
min_limit = min(min_limit, tmp);
|
|
tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
|
|
min_memsw_limit = min(min_memsw_limit, tmp);
|
|
}
|
|
out:
|
|
*mem_limit = min_limit;
|
|
*memsw_limit = min_memsw_limit;
|
|
}
|
|
|
|
static int mem_cgroup_reset(struct cgroup_subsys_state *css, unsigned int event)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
int name;
|
|
enum res_type type;
|
|
|
|
type = MEMFILE_TYPE(event);
|
|
name = MEMFILE_ATTR(event);
|
|
|
|
switch (name) {
|
|
case RES_MAX_USAGE:
|
|
if (type == _MEM)
|
|
res_counter_reset_max(&memcg->res);
|
|
else if (type == _MEMSWAP)
|
|
res_counter_reset_max(&memcg->memsw);
|
|
else if (type == _KMEM)
|
|
res_counter_reset_max(&memcg->kmem);
|
|
else
|
|
return -EINVAL;
|
|
break;
|
|
case RES_FAILCNT:
|
|
if (type == _MEM)
|
|
res_counter_reset_failcnt(&memcg->res);
|
|
else if (type == _MEMSWAP)
|
|
res_counter_reset_failcnt(&memcg->memsw);
|
|
else if (type == _KMEM)
|
|
res_counter_reset_failcnt(&memcg->kmem);
|
|
else
|
|
return -EINVAL;
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
return mem_cgroup_from_css(css)->move_charge_at_immigrate;
|
|
}
|
|
|
|
#ifdef CONFIG_MMU
|
|
static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
if (val >= (1 << NR_MOVE_TYPE))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* No kind of locking is needed in here, because ->can_attach() will
|
|
* check this value once in the beginning of the process, and then carry
|
|
* on with stale data. This means that changes to this value will only
|
|
* affect task migrations starting after the change.
|
|
*/
|
|
memcg->move_charge_at_immigrate = val;
|
|
return 0;
|
|
}
|
|
#else
|
|
static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_NUMA
|
|
static int memcg_numa_stat_show(struct seq_file *m, void *v)
|
|
{
|
|
struct numa_stat {
|
|
const char *name;
|
|
unsigned int lru_mask;
|
|
};
|
|
|
|
static const struct numa_stat stats[] = {
|
|
{ "total", LRU_ALL },
|
|
{ "file", LRU_ALL_FILE },
|
|
{ "anon", LRU_ALL_ANON },
|
|
{ "unevictable", BIT(LRU_UNEVICTABLE) },
|
|
};
|
|
const struct numa_stat *stat;
|
|
int nid;
|
|
unsigned long nr;
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
|
|
|
|
for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
|
|
nr = mem_cgroup_nr_lru_pages(memcg, stat->lru_mask);
|
|
seq_printf(m, "%s=%lu", stat->name, nr);
|
|
for_each_node_state(nid, N_MEMORY) {
|
|
nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
|
|
stat->lru_mask);
|
|
seq_printf(m, " N%d=%lu", nid, nr);
|
|
}
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
|
|
struct mem_cgroup *iter;
|
|
|
|
nr = 0;
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
nr += mem_cgroup_nr_lru_pages(iter, stat->lru_mask);
|
|
seq_printf(m, "hierarchical_%s=%lu", stat->name, nr);
|
|
for_each_node_state(nid, N_MEMORY) {
|
|
nr = 0;
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
nr += mem_cgroup_node_nr_lru_pages(
|
|
iter, nid, stat->lru_mask);
|
|
seq_printf(m, " N%d=%lu", nid, nr);
|
|
}
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_NUMA */
|
|
|
|
static inline void mem_cgroup_lru_names_not_uptodate(void)
|
|
{
|
|
BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS);
|
|
}
|
|
|
|
static int memcg_stat_show(struct seq_file *m, void *v)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
|
|
struct mem_cgroup *mi;
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
|
|
if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
|
|
continue;
|
|
seq_printf(m, "%s %ld\n", mem_cgroup_stat_names[i],
|
|
mem_cgroup_read_stat(memcg, i) * PAGE_SIZE);
|
|
}
|
|
|
|
for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++)
|
|
seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i],
|
|
mem_cgroup_read_events(memcg, i));
|
|
|
|
for (i = 0; i < NR_LRU_LISTS; i++)
|
|
seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i],
|
|
mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE);
|
|
|
|
/* Hierarchical information */
|
|
{
|
|
unsigned long long limit, memsw_limit;
|
|
memcg_get_hierarchical_limit(memcg, &limit, &memsw_limit);
|
|
seq_printf(m, "hierarchical_memory_limit %llu\n", limit);
|
|
if (do_swap_account)
|
|
seq_printf(m, "hierarchical_memsw_limit %llu\n",
|
|
memsw_limit);
|
|
}
|
|
|
|
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
|
|
long long val = 0;
|
|
|
|
if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
|
|
continue;
|
|
for_each_mem_cgroup_tree(mi, memcg)
|
|
val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE;
|
|
seq_printf(m, "total_%s %lld\n", mem_cgroup_stat_names[i], val);
|
|
}
|
|
|
|
for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
|
|
unsigned long long val = 0;
|
|
|
|
for_each_mem_cgroup_tree(mi, memcg)
|
|
val += mem_cgroup_read_events(mi, i);
|
|
seq_printf(m, "total_%s %llu\n",
|
|
mem_cgroup_events_names[i], val);
|
|
}
|
|
|
|
for (i = 0; i < NR_LRU_LISTS; i++) {
|
|
unsigned long long val = 0;
|
|
|
|
for_each_mem_cgroup_tree(mi, memcg)
|
|
val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE;
|
|
seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val);
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_VM
|
|
{
|
|
int nid, zid;
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct zone_reclaim_stat *rstat;
|
|
unsigned long recent_rotated[2] = {0, 0};
|
|
unsigned long recent_scanned[2] = {0, 0};
|
|
|
|
for_each_online_node(nid)
|
|
for (zid = 0; zid < MAX_NR_ZONES; zid++) {
|
|
mz = mem_cgroup_zoneinfo(memcg, nid, zid);
|
|
rstat = &mz->lruvec.reclaim_stat;
|
|
|
|
recent_rotated[0] += rstat->recent_rotated[0];
|
|
recent_rotated[1] += rstat->recent_rotated[1];
|
|
recent_scanned[0] += rstat->recent_scanned[0];
|
|
recent_scanned[1] += rstat->recent_scanned[1];
|
|
}
|
|
seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]);
|
|
seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]);
|
|
seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]);
|
|
seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]);
|
|
}
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
return mem_cgroup_swappiness(memcg);
|
|
}
|
|
|
|
static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css));
|
|
|
|
if (val > 100 || !parent)
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&memcg_create_mutex);
|
|
|
|
/* If under hierarchy, only empty-root can set this value */
|
|
if ((parent->use_hierarchy) || memcg_has_children(memcg)) {
|
|
mutex_unlock(&memcg_create_mutex);
|
|
return -EINVAL;
|
|
}
|
|
|
|
memcg->swappiness = val;
|
|
|
|
mutex_unlock(&memcg_create_mutex);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
|
|
{
|
|
struct mem_cgroup_threshold_ary *t;
|
|
u64 usage;
|
|
int i;
|
|
|
|
rcu_read_lock();
|
|
if (!swap)
|
|
t = rcu_dereference(memcg->thresholds.primary);
|
|
else
|
|
t = rcu_dereference(memcg->memsw_thresholds.primary);
|
|
|
|
if (!t)
|
|
goto unlock;
|
|
|
|
usage = mem_cgroup_usage(memcg, swap);
|
|
|
|
/*
|
|
* current_threshold points to threshold just below or equal to usage.
|
|
* If it's not true, a threshold was crossed after last
|
|
* call of __mem_cgroup_threshold().
|
|
*/
|
|
i = t->current_threshold;
|
|
|
|
/*
|
|
* Iterate backward over array of thresholds starting from
|
|
* current_threshold and check if a threshold is crossed.
|
|
* If none of thresholds below usage is crossed, we read
|
|
* only one element of the array here.
|
|
*/
|
|
for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--)
|
|
eventfd_signal(t->entries[i].eventfd, 1);
|
|
|
|
/* i = current_threshold + 1 */
|
|
i++;
|
|
|
|
/*
|
|
* Iterate forward over array of thresholds starting from
|
|
* current_threshold+1 and check if a threshold is crossed.
|
|
* If none of thresholds above usage is crossed, we read
|
|
* only one element of the array here.
|
|
*/
|
|
for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++)
|
|
eventfd_signal(t->entries[i].eventfd, 1);
|
|
|
|
/* Update current_threshold */
|
|
t->current_threshold = i - 1;
|
|
unlock:
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void mem_cgroup_threshold(struct mem_cgroup *memcg)
|
|
{
|
|
while (memcg) {
|
|
__mem_cgroup_threshold(memcg, false);
|
|
if (do_swap_account)
|
|
__mem_cgroup_threshold(memcg, true);
|
|
|
|
memcg = parent_mem_cgroup(memcg);
|
|
}
|
|
}
|
|
|
|
static int compare_thresholds(const void *a, const void *b)
|
|
{
|
|
const struct mem_cgroup_threshold *_a = a;
|
|
const struct mem_cgroup_threshold *_b = b;
|
|
|
|
if (_a->threshold > _b->threshold)
|
|
return 1;
|
|
|
|
if (_a->threshold < _b->threshold)
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup_eventfd_list *ev;
|
|
|
|
list_for_each_entry(ev, &memcg->oom_notify, list)
|
|
eventfd_signal(ev->eventfd, 1);
|
|
return 0;
|
|
}
|
|
|
|
static void mem_cgroup_oom_notify(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
mem_cgroup_oom_notify_cb(iter);
|
|
}
|
|
|
|
static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd, const char *args, enum res_type type)
|
|
{
|
|
struct mem_cgroup_thresholds *thresholds;
|
|
struct mem_cgroup_threshold_ary *new;
|
|
u64 threshold, usage;
|
|
int i, size, ret;
|
|
|
|
ret = res_counter_memparse_write_strategy(args, &threshold);
|
|
if (ret)
|
|
return ret;
|
|
|
|
mutex_lock(&memcg->thresholds_lock);
|
|
|
|
if (type == _MEM)
|
|
thresholds = &memcg->thresholds;
|
|
else if (type == _MEMSWAP)
|
|
thresholds = &memcg->memsw_thresholds;
|
|
else
|
|
BUG();
|
|
|
|
usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
|
|
|
|
/* Check if a threshold crossed before adding a new one */
|
|
if (thresholds->primary)
|
|
__mem_cgroup_threshold(memcg, type == _MEMSWAP);
|
|
|
|
size = thresholds->primary ? thresholds->primary->size + 1 : 1;
|
|
|
|
/* Allocate memory for new array of thresholds */
|
|
new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold),
|
|
GFP_KERNEL);
|
|
if (!new) {
|
|
ret = -ENOMEM;
|
|
goto unlock;
|
|
}
|
|
new->size = size;
|
|
|
|
/* Copy thresholds (if any) to new array */
|
|
if (thresholds->primary) {
|
|
memcpy(new->entries, thresholds->primary->entries, (size - 1) *
|
|
sizeof(struct mem_cgroup_threshold));
|
|
}
|
|
|
|
/* Add new threshold */
|
|
new->entries[size - 1].eventfd = eventfd;
|
|
new->entries[size - 1].threshold = threshold;
|
|
|
|
/* Sort thresholds. Registering of new threshold isn't time-critical */
|
|
sort(new->entries, size, sizeof(struct mem_cgroup_threshold),
|
|
compare_thresholds, NULL);
|
|
|
|
/* Find current threshold */
|
|
new->current_threshold = -1;
|
|
for (i = 0; i < size; i++) {
|
|
if (new->entries[i].threshold <= usage) {
|
|
/*
|
|
* new->current_threshold will not be used until
|
|
* rcu_assign_pointer(), so it's safe to increment
|
|
* it here.
|
|
*/
|
|
++new->current_threshold;
|
|
} else
|
|
break;
|
|
}
|
|
|
|
/* Free old spare buffer and save old primary buffer as spare */
|
|
kfree(thresholds->spare);
|
|
thresholds->spare = thresholds->primary;
|
|
|
|
rcu_assign_pointer(thresholds->primary, new);
|
|
|
|
/* To be sure that nobody uses thresholds */
|
|
synchronize_rcu();
|
|
|
|
unlock:
|
|
mutex_unlock(&memcg->thresholds_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd, const char *args)
|
|
{
|
|
return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEM);
|
|
}
|
|
|
|
static int memsw_cgroup_usage_register_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd, const char *args)
|
|
{
|
|
return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEMSWAP);
|
|
}
|
|
|
|
static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd, enum res_type type)
|
|
{
|
|
struct mem_cgroup_thresholds *thresholds;
|
|
struct mem_cgroup_threshold_ary *new;
|
|
u64 usage;
|
|
int i, j, size;
|
|
|
|
mutex_lock(&memcg->thresholds_lock);
|
|
if (type == _MEM)
|
|
thresholds = &memcg->thresholds;
|
|
else if (type == _MEMSWAP)
|
|
thresholds = &memcg->memsw_thresholds;
|
|
else
|
|
BUG();
|
|
|
|
if (!thresholds->primary)
|
|
goto unlock;
|
|
|
|
usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
|
|
|
|
/* Check if a threshold crossed before removing */
|
|
__mem_cgroup_threshold(memcg, type == _MEMSWAP);
|
|
|
|
/* Calculate new number of threshold */
|
|
size = 0;
|
|
for (i = 0; i < thresholds->primary->size; i++) {
|
|
if (thresholds->primary->entries[i].eventfd != eventfd)
|
|
size++;
|
|
}
|
|
|
|
new = thresholds->spare;
|
|
|
|
/* Set thresholds array to NULL if we don't have thresholds */
|
|
if (!size) {
|
|
kfree(new);
|
|
new = NULL;
|
|
goto swap_buffers;
|
|
}
|
|
|
|
new->size = size;
|
|
|
|
/* Copy thresholds and find current threshold */
|
|
new->current_threshold = -1;
|
|
for (i = 0, j = 0; i < thresholds->primary->size; i++) {
|
|
if (thresholds->primary->entries[i].eventfd == eventfd)
|
|
continue;
|
|
|
|
new->entries[j] = thresholds->primary->entries[i];
|
|
if (new->entries[j].threshold <= usage) {
|
|
/*
|
|
* new->current_threshold will not be used
|
|
* until rcu_assign_pointer(), so it's safe to increment
|
|
* it here.
|
|
*/
|
|
++new->current_threshold;
|
|
}
|
|
j++;
|
|
}
|
|
|
|
swap_buffers:
|
|
/* Swap primary and spare array */
|
|
thresholds->spare = thresholds->primary;
|
|
/* If all events are unregistered, free the spare array */
|
|
if (!new) {
|
|
kfree(thresholds->spare);
|
|
thresholds->spare = NULL;
|
|
}
|
|
|
|
rcu_assign_pointer(thresholds->primary, new);
|
|
|
|
/* To be sure that nobody uses thresholds */
|
|
synchronize_rcu();
|
|
unlock:
|
|
mutex_unlock(&memcg->thresholds_lock);
|
|
}
|
|
|
|
static void mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd)
|
|
{
|
|
return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEM);
|
|
}
|
|
|
|
static void memsw_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd)
|
|
{
|
|
return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEMSWAP);
|
|
}
|
|
|
|
static int mem_cgroup_oom_register_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd, const char *args)
|
|
{
|
|
struct mem_cgroup_eventfd_list *event;
|
|
|
|
event = kmalloc(sizeof(*event), GFP_KERNEL);
|
|
if (!event)
|
|
return -ENOMEM;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
|
|
event->eventfd = eventfd;
|
|
list_add(&event->list, &memcg->oom_notify);
|
|
|
|
/* already in OOM ? */
|
|
if (atomic_read(&memcg->under_oom))
|
|
eventfd_signal(eventfd, 1);
|
|
spin_unlock(&memcg_oom_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void mem_cgroup_oom_unregister_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd)
|
|
{
|
|
struct mem_cgroup_eventfd_list *ev, *tmp;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
|
|
list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) {
|
|
if (ev->eventfd == eventfd) {
|
|
list_del(&ev->list);
|
|
kfree(ev);
|
|
}
|
|
}
|
|
|
|
spin_unlock(&memcg_oom_lock);
|
|
}
|
|
|
|
static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(sf));
|
|
|
|
seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable);
|
|
seq_printf(sf, "under_oom %d\n", (bool)atomic_read(&memcg->under_oom));
|
|
return 0;
|
|
}
|
|
|
|
static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css));
|
|
|
|
/* cannot set to root cgroup and only 0 and 1 are allowed */
|
|
if (!parent || !((val == 0) || (val == 1)))
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&memcg_create_mutex);
|
|
/* oom-kill-disable is a flag for subhierarchy. */
|
|
if ((parent->use_hierarchy) || memcg_has_children(memcg)) {
|
|
mutex_unlock(&memcg_create_mutex);
|
|
return -EINVAL;
|
|
}
|
|
memcg->oom_kill_disable = val;
|
|
if (!val)
|
|
memcg_oom_recover(memcg);
|
|
mutex_unlock(&memcg_create_mutex);
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
|
|
{
|
|
int ret;
|
|
|
|
memcg->kmemcg_id = -1;
|
|
ret = memcg_propagate_kmem(memcg);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return mem_cgroup_sockets_init(memcg, ss);
|
|
}
|
|
|
|
static void memcg_destroy_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
mem_cgroup_sockets_destroy(memcg);
|
|
}
|
|
|
|
static void kmem_cgroup_css_offline(struct mem_cgroup *memcg)
|
|
{
|
|
if (!memcg_kmem_is_active(memcg))
|
|
return;
|
|
|
|
/*
|
|
* kmem charges can outlive the cgroup. In the case of slab
|
|
* pages, for instance, a page contain objects from various
|
|
* processes. As we prevent from taking a reference for every
|
|
* such allocation we have to be careful when doing uncharge
|
|
* (see memcg_uncharge_kmem) and here during offlining.
|
|
*
|
|
* The idea is that that only the _last_ uncharge which sees
|
|
* the dead memcg will drop the last reference. An additional
|
|
* reference is taken here before the group is marked dead
|
|
* which is then paired with css_put during uncharge resp. here.
|
|
*
|
|
* Although this might sound strange as this path is called from
|
|
* css_offline() when the referencemight have dropped down to 0
|
|
* and shouldn't be incremented anymore (css_tryget would fail)
|
|
* we do not have other options because of the kmem allocations
|
|
* lifetime.
|
|
*/
|
|
css_get(&memcg->css);
|
|
|
|
memcg_kmem_mark_dead(memcg);
|
|
|
|
if (res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0)
|
|
return;
|
|
|
|
if (memcg_kmem_test_and_clear_dead(memcg))
|
|
css_put(&memcg->css);
|
|
}
|
|
#else
|
|
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void memcg_destroy_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
|
|
static void kmem_cgroup_css_offline(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* DO NOT USE IN NEW FILES.
|
|
*
|
|
* "cgroup.event_control" implementation.
|
|
*
|
|
* This is way over-engineered. It tries to support fully configurable
|
|
* events for each user. Such level of flexibility is completely
|
|
* unnecessary especially in the light of the planned unified hierarchy.
|
|
*
|
|
* Please deprecate this and replace with something simpler if at all
|
|
* possible.
|
|
*/
|
|
|
|
/*
|
|
* Unregister event and free resources.
|
|
*
|
|
* Gets called from workqueue.
|
|
*/
|
|
static void memcg_event_remove(struct work_struct *work)
|
|
{
|
|
struct mem_cgroup_event *event =
|
|
container_of(work, struct mem_cgroup_event, remove);
|
|
struct mem_cgroup *memcg = event->memcg;
|
|
|
|
remove_wait_queue(event->wqh, &event->wait);
|
|
|
|
event->unregister_event(memcg, event->eventfd);
|
|
|
|
/* Notify userspace the event is going away. */
|
|
eventfd_signal(event->eventfd, 1);
|
|
|
|
eventfd_ctx_put(event->eventfd);
|
|
kfree(event);
|
|
css_put(&memcg->css);
|
|
}
|
|
|
|
/*
|
|
* Gets called on POLLHUP on eventfd when user closes it.
|
|
*
|
|
* Called with wqh->lock held and interrupts disabled.
|
|
*/
|
|
static int memcg_event_wake(wait_queue_t *wait, unsigned mode,
|
|
int sync, void *key)
|
|
{
|
|
struct mem_cgroup_event *event =
|
|
container_of(wait, struct mem_cgroup_event, wait);
|
|
struct mem_cgroup *memcg = event->memcg;
|
|
unsigned long flags = (unsigned long)key;
|
|
|
|
if (flags & POLLHUP) {
|
|
/*
|
|
* If the event has been detached at cgroup removal, we
|
|
* can simply return knowing the other side will cleanup
|
|
* for us.
|
|
*
|
|
* We can't race against event freeing since the other
|
|
* side will require wqh->lock via remove_wait_queue(),
|
|
* which we hold.
|
|
*/
|
|
spin_lock(&memcg->event_list_lock);
|
|
if (!list_empty(&event->list)) {
|
|
list_del_init(&event->list);
|
|
/*
|
|
* We are in atomic context, but cgroup_event_remove()
|
|
* may sleep, so we have to call it in workqueue.
|
|
*/
|
|
schedule_work(&event->remove);
|
|
}
|
|
spin_unlock(&memcg->event_list_lock);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void memcg_event_ptable_queue_proc(struct file *file,
|
|
wait_queue_head_t *wqh, poll_table *pt)
|
|
{
|
|
struct mem_cgroup_event *event =
|
|
container_of(pt, struct mem_cgroup_event, pt);
|
|
|
|
event->wqh = wqh;
|
|
add_wait_queue(wqh, &event->wait);
|
|
}
|
|
|
|
/*
|
|
* DO NOT USE IN NEW FILES.
|
|
*
|
|
* Parse input and register new cgroup event handler.
|
|
*
|
|
* Input must be in format '<event_fd> <control_fd> <args>'.
|
|
* Interpretation of args is defined by control file implementation.
|
|
*/
|
|
static int memcg_write_event_control(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, const char *buffer)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup_event *event;
|
|
struct cgroup_subsys_state *cfile_css;
|
|
unsigned int efd, cfd;
|
|
struct fd efile;
|
|
struct fd cfile;
|
|
const char *name;
|
|
char *endp;
|
|
int ret;
|
|
|
|
efd = simple_strtoul(buffer, &endp, 10);
|
|
if (*endp != ' ')
|
|
return -EINVAL;
|
|
buffer = endp + 1;
|
|
|
|
cfd = simple_strtoul(buffer, &endp, 10);
|
|
if ((*endp != ' ') && (*endp != '\0'))
|
|
return -EINVAL;
|
|
buffer = endp + 1;
|
|
|
|
event = kzalloc(sizeof(*event), GFP_KERNEL);
|
|
if (!event)
|
|
return -ENOMEM;
|
|
|
|
event->memcg = memcg;
|
|
INIT_LIST_HEAD(&event->list);
|
|
init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc);
|
|
init_waitqueue_func_entry(&event->wait, memcg_event_wake);
|
|
INIT_WORK(&event->remove, memcg_event_remove);
|
|
|
|
efile = fdget(efd);
|
|
if (!efile.file) {
|
|
ret = -EBADF;
|
|
goto out_kfree;
|
|
}
|
|
|
|
event->eventfd = eventfd_ctx_fileget(efile.file);
|
|
if (IS_ERR(event->eventfd)) {
|
|
ret = PTR_ERR(event->eventfd);
|
|
goto out_put_efile;
|
|
}
|
|
|
|
cfile = fdget(cfd);
|
|
if (!cfile.file) {
|
|
ret = -EBADF;
|
|
goto out_put_eventfd;
|
|
}
|
|
|
|
/* the process need read permission on control file */
|
|
/* AV: shouldn't we check that it's been opened for read instead? */
|
|
ret = inode_permission(file_inode(cfile.file), MAY_READ);
|
|
if (ret < 0)
|
|
goto out_put_cfile;
|
|
|
|
/*
|
|
* Determine the event callbacks and set them in @event. This used
|
|
* to be done via struct cftype but cgroup core no longer knows
|
|
* about these events. The following is crude but the whole thing
|
|
* is for compatibility anyway.
|
|
*
|
|
* DO NOT ADD NEW FILES.
|
|
*/
|
|
name = cfile.file->f_dentry->d_name.name;
|
|
|
|
if (!strcmp(name, "memory.usage_in_bytes")) {
|
|
event->register_event = mem_cgroup_usage_register_event;
|
|
event->unregister_event = mem_cgroup_usage_unregister_event;
|
|
} else if (!strcmp(name, "memory.oom_control")) {
|
|
event->register_event = mem_cgroup_oom_register_event;
|
|
event->unregister_event = mem_cgroup_oom_unregister_event;
|
|
} else if (!strcmp(name, "memory.pressure_level")) {
|
|
event->register_event = vmpressure_register_event;
|
|
event->unregister_event = vmpressure_unregister_event;
|
|
} else if (!strcmp(name, "memory.memsw.usage_in_bytes")) {
|
|
event->register_event = memsw_cgroup_usage_register_event;
|
|
event->unregister_event = memsw_cgroup_usage_unregister_event;
|
|
} else {
|
|
ret = -EINVAL;
|
|
goto out_put_cfile;
|
|
}
|
|
|
|
/*
|
|
* Verify @cfile should belong to @css. Also, remaining events are
|
|
* automatically removed on cgroup destruction but the removal is
|
|
* asynchronous, so take an extra ref on @css.
|
|
*/
|
|
rcu_read_lock();
|
|
|
|
ret = -EINVAL;
|
|
cfile_css = css_from_dir(cfile.file->f_dentry->d_parent,
|
|
&mem_cgroup_subsys);
|
|
if (cfile_css == css && css_tryget(css))
|
|
ret = 0;
|
|
|
|
rcu_read_unlock();
|
|
if (ret)
|
|
goto out_put_cfile;
|
|
|
|
ret = event->register_event(memcg, event->eventfd, buffer);
|
|
if (ret)
|
|
goto out_put_css;
|
|
|
|
efile.file->f_op->poll(efile.file, &event->pt);
|
|
|
|
spin_lock(&memcg->event_list_lock);
|
|
list_add(&event->list, &memcg->event_list);
|
|
spin_unlock(&memcg->event_list_lock);
|
|
|
|
fdput(cfile);
|
|
fdput(efile);
|
|
|
|
return 0;
|
|
|
|
out_put_css:
|
|
css_put(css);
|
|
out_put_cfile:
|
|
fdput(cfile);
|
|
out_put_eventfd:
|
|
eventfd_ctx_put(event->eventfd);
|
|
out_put_efile:
|
|
fdput(efile);
|
|
out_kfree:
|
|
kfree(event);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct cftype mem_cgroup_files[] = {
|
|
{
|
|
.name = "usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "max_usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
|
|
.trigger = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
|
|
.write_string = mem_cgroup_write,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "soft_limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
|
|
.write_string = mem_cgroup_write,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "failcnt",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
|
|
.trigger = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "stat",
|
|
.seq_show = memcg_stat_show,
|
|
},
|
|
{
|
|
.name = "force_empty",
|
|
.trigger = mem_cgroup_force_empty_write,
|
|
},
|
|
{
|
|
.name = "use_hierarchy",
|
|
.flags = CFTYPE_INSANE,
|
|
.write_u64 = mem_cgroup_hierarchy_write,
|
|
.read_u64 = mem_cgroup_hierarchy_read,
|
|
},
|
|
{
|
|
.name = "cgroup.event_control", /* XXX: for compat */
|
|
.write_string = memcg_write_event_control,
|
|
.flags = CFTYPE_NO_PREFIX,
|
|
.mode = S_IWUGO,
|
|
},
|
|
{
|
|
.name = "swappiness",
|
|
.read_u64 = mem_cgroup_swappiness_read,
|
|
.write_u64 = mem_cgroup_swappiness_write,
|
|
},
|
|
{
|
|
.name = "move_charge_at_immigrate",
|
|
.read_u64 = mem_cgroup_move_charge_read,
|
|
.write_u64 = mem_cgroup_move_charge_write,
|
|
},
|
|
{
|
|
.name = "oom_control",
|
|
.seq_show = mem_cgroup_oom_control_read,
|
|
.write_u64 = mem_cgroup_oom_control_write,
|
|
.private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
|
|
},
|
|
{
|
|
.name = "pressure_level",
|
|
},
|
|
#ifdef CONFIG_NUMA
|
|
{
|
|
.name = "numa_stat",
|
|
.seq_show = memcg_numa_stat_show,
|
|
},
|
|
#endif
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
{
|
|
.name = "kmem.limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT),
|
|
.write_string = mem_cgroup_write,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "kmem.usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_KMEM, RES_USAGE),
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "kmem.failcnt",
|
|
.private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT),
|
|
.trigger = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "kmem.max_usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE),
|
|
.trigger = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
#ifdef CONFIG_SLABINFO
|
|
{
|
|
.name = "kmem.slabinfo",
|
|
.seq_show = mem_cgroup_slabinfo_read,
|
|
},
|
|
#endif
|
|
#endif
|
|
{ }, /* terminate */
|
|
};
|
|
|
|
#ifdef CONFIG_MEMCG_SWAP
|
|
static struct cftype memsw_cgroup_files[] = {
|
|
{
|
|
.name = "memsw.usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "memsw.max_usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
|
|
.trigger = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "memsw.limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
|
|
.write_string = mem_cgroup_write,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "memsw.failcnt",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
|
|
.trigger = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{ }, /* terminate */
|
|
};
|
|
#endif
|
|
static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
|
|
{
|
|
struct mem_cgroup_per_node *pn;
|
|
struct mem_cgroup_per_zone *mz;
|
|
int zone, tmp = node;
|
|
/*
|
|
* This routine is called against possible nodes.
|
|
* But it's BUG to call kmalloc() against offline node.
|
|
*
|
|
* TODO: this routine can waste much memory for nodes which will
|
|
* never be onlined. It's better to use memory hotplug callback
|
|
* function.
|
|
*/
|
|
if (!node_state(node, N_NORMAL_MEMORY))
|
|
tmp = -1;
|
|
pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
|
|
if (!pn)
|
|
return 1;
|
|
|
|
for (zone = 0; zone < MAX_NR_ZONES; zone++) {
|
|
mz = &pn->zoneinfo[zone];
|
|
lruvec_init(&mz->lruvec);
|
|
mz->usage_in_excess = 0;
|
|
mz->on_tree = false;
|
|
mz->memcg = memcg;
|
|
}
|
|
memcg->nodeinfo[node] = pn;
|
|
return 0;
|
|
}
|
|
|
|
static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
|
|
{
|
|
kfree(memcg->nodeinfo[node]);
|
|
}
|
|
|
|
static struct mem_cgroup *mem_cgroup_alloc(void)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
size_t size;
|
|
|
|
size = sizeof(struct mem_cgroup);
|
|
size += nr_node_ids * sizeof(struct mem_cgroup_per_node *);
|
|
|
|
memcg = kzalloc(size, GFP_KERNEL);
|
|
if (!memcg)
|
|
return NULL;
|
|
|
|
memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
|
|
if (!memcg->stat)
|
|
goto out_free;
|
|
spin_lock_init(&memcg->pcp_counter_lock);
|
|
return memcg;
|
|
|
|
out_free:
|
|
kfree(memcg);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* At destroying mem_cgroup, references from swap_cgroup can remain.
|
|
* (scanning all at force_empty is too costly...)
|
|
*
|
|
* Instead of clearing all references at force_empty, we remember
|
|
* the number of reference from swap_cgroup and free mem_cgroup when
|
|
* it goes down to 0.
|
|
*
|
|
* Removal of cgroup itself succeeds regardless of refs from swap.
|
|
*/
|
|
|
|
static void __mem_cgroup_free(struct mem_cgroup *memcg)
|
|
{
|
|
int node;
|
|
|
|
mem_cgroup_remove_from_trees(memcg);
|
|
|
|
for_each_node(node)
|
|
free_mem_cgroup_per_zone_info(memcg, node);
|
|
|
|
free_percpu(memcg->stat);
|
|
|
|
/*
|
|
* We need to make sure that (at least for now), the jump label
|
|
* destruction code runs outside of the cgroup lock. This is because
|
|
* get_online_cpus(), which is called from the static_branch update,
|
|
* can't be called inside the cgroup_lock. cpusets are the ones
|
|
* enforcing this dependency, so if they ever change, we might as well.
|
|
*
|
|
* schedule_work() will guarantee this happens. Be careful if you need
|
|
* to move this code around, and make sure it is outside
|
|
* the cgroup_lock.
|
|
*/
|
|
disarm_static_keys(memcg);
|
|
kfree(memcg);
|
|
}
|
|
|
|
/*
|
|
* Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
|
|
*/
|
|
struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
|
|
{
|
|
if (!memcg->res.parent)
|
|
return NULL;
|
|
return mem_cgroup_from_res_counter(memcg->res.parent, res);
|
|
}
|
|
EXPORT_SYMBOL(parent_mem_cgroup);
|
|
|
|
static void __init mem_cgroup_soft_limit_tree_init(void)
|
|
{
|
|
struct mem_cgroup_tree_per_node *rtpn;
|
|
struct mem_cgroup_tree_per_zone *rtpz;
|
|
int tmp, node, zone;
|
|
|
|
for_each_node(node) {
|
|
tmp = node;
|
|
if (!node_state(node, N_NORMAL_MEMORY))
|
|
tmp = -1;
|
|
rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
|
|
BUG_ON(!rtpn);
|
|
|
|
soft_limit_tree.rb_tree_per_node[node] = rtpn;
|
|
|
|
for (zone = 0; zone < MAX_NR_ZONES; zone++) {
|
|
rtpz = &rtpn->rb_tree_per_zone[zone];
|
|
rtpz->rb_root = RB_ROOT;
|
|
spin_lock_init(&rtpz->lock);
|
|
}
|
|
}
|
|
}
|
|
|
|
static struct cgroup_subsys_state * __ref
|
|
mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
long error = -ENOMEM;
|
|
int node;
|
|
|
|
memcg = mem_cgroup_alloc();
|
|
if (!memcg)
|
|
return ERR_PTR(error);
|
|
|
|
for_each_node(node)
|
|
if (alloc_mem_cgroup_per_zone_info(memcg, node))
|
|
goto free_out;
|
|
|
|
/* root ? */
|
|
if (parent_css == NULL) {
|
|
root_mem_cgroup = memcg;
|
|
res_counter_init(&memcg->res, NULL);
|
|
res_counter_init(&memcg->memsw, NULL);
|
|
res_counter_init(&memcg->kmem, NULL);
|
|
}
|
|
|
|
memcg->last_scanned_node = MAX_NUMNODES;
|
|
INIT_LIST_HEAD(&memcg->oom_notify);
|
|
memcg->move_charge_at_immigrate = 0;
|
|
mutex_init(&memcg->thresholds_lock);
|
|
spin_lock_init(&memcg->move_lock);
|
|
vmpressure_init(&memcg->vmpressure);
|
|
INIT_LIST_HEAD(&memcg->event_list);
|
|
spin_lock_init(&memcg->event_list_lock);
|
|
|
|
return &memcg->css;
|
|
|
|
free_out:
|
|
__mem_cgroup_free(memcg);
|
|
return ERR_PTR(error);
|
|
}
|
|
|
|
static int
|
|
mem_cgroup_css_online(struct cgroup_subsys_state *css)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(css));
|
|
|
|
if (css->cgroup->id > MEM_CGROUP_ID_MAX)
|
|
return -ENOSPC;
|
|
|
|
if (!parent)
|
|
return 0;
|
|
|
|
mutex_lock(&memcg_create_mutex);
|
|
|
|
memcg->use_hierarchy = parent->use_hierarchy;
|
|
memcg->oom_kill_disable = parent->oom_kill_disable;
|
|
memcg->swappiness = mem_cgroup_swappiness(parent);
|
|
|
|
if (parent->use_hierarchy) {
|
|
res_counter_init(&memcg->res, &parent->res);
|
|
res_counter_init(&memcg->memsw, &parent->memsw);
|
|
res_counter_init(&memcg->kmem, &parent->kmem);
|
|
|
|
/*
|
|
* No need to take a reference to the parent because cgroup
|
|
* core guarantees its existence.
|
|
*/
|
|
} else {
|
|
res_counter_init(&memcg->res, NULL);
|
|
res_counter_init(&memcg->memsw, NULL);
|
|
res_counter_init(&memcg->kmem, NULL);
|
|
/*
|
|
* Deeper hierachy with use_hierarchy == false doesn't make
|
|
* much sense so let cgroup subsystem know about this
|
|
* unfortunate state in our controller.
|
|
*/
|
|
if (parent != root_mem_cgroup)
|
|
mem_cgroup_subsys.broken_hierarchy = true;
|
|
}
|
|
mutex_unlock(&memcg_create_mutex);
|
|
|
|
return memcg_init_kmem(memcg, &mem_cgroup_subsys);
|
|
}
|
|
|
|
/*
|
|
* Announce all parents that a group from their hierarchy is gone.
|
|
*/
|
|
static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *parent = memcg;
|
|
|
|
while ((parent = parent_mem_cgroup(parent)))
|
|
mem_cgroup_iter_invalidate(parent);
|
|
|
|
/*
|
|
* if the root memcg is not hierarchical we have to check it
|
|
* explicitely.
|
|
*/
|
|
if (!root_mem_cgroup->use_hierarchy)
|
|
mem_cgroup_iter_invalidate(root_mem_cgroup);
|
|
}
|
|
|
|
static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup_event *event, *tmp;
|
|
struct cgroup_subsys_state *iter;
|
|
|
|
/*
|
|
* Unregister events and notify userspace.
|
|
* Notify userspace about cgroup removing only after rmdir of cgroup
|
|
* directory to avoid race between userspace and kernelspace.
|
|
*/
|
|
spin_lock(&memcg->event_list_lock);
|
|
list_for_each_entry_safe(event, tmp, &memcg->event_list, list) {
|
|
list_del_init(&event->list);
|
|
schedule_work(&event->remove);
|
|
}
|
|
spin_unlock(&memcg->event_list_lock);
|
|
|
|
kmem_cgroup_css_offline(memcg);
|
|
|
|
mem_cgroup_invalidate_reclaim_iterators(memcg);
|
|
|
|
/*
|
|
* This requires that offlining is serialized. Right now that is
|
|
* guaranteed because css_killed_work_fn() holds the cgroup_mutex.
|
|
*/
|
|
css_for_each_descendant_post(iter, css)
|
|
mem_cgroup_reparent_charges(mem_cgroup_from_css(iter));
|
|
|
|
mem_cgroup_destroy_all_caches(memcg);
|
|
vmpressure_cleanup(&memcg->vmpressure);
|
|
}
|
|
|
|
static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
/*
|
|
* XXX: css_offline() would be where we should reparent all
|
|
* memory to prepare the cgroup for destruction. However,
|
|
* memcg does not do css_tryget() and res_counter charging
|
|
* under the same RCU lock region, which means that charging
|
|
* could race with offlining. Offlining only happens to
|
|
* cgroups with no tasks in them but charges can show up
|
|
* without any tasks from the swapin path when the target
|
|
* memcg is looked up from the swapout record and not from the
|
|
* current task as it usually is. A race like this can leak
|
|
* charges and put pages with stale cgroup pointers into
|
|
* circulation:
|
|
*
|
|
* #0 #1
|
|
* lookup_swap_cgroup_id()
|
|
* rcu_read_lock()
|
|
* mem_cgroup_lookup()
|
|
* css_tryget()
|
|
* rcu_read_unlock()
|
|
* disable css_tryget()
|
|
* call_rcu()
|
|
* offline_css()
|
|
* reparent_charges()
|
|
* res_counter_charge()
|
|
* css_put()
|
|
* css_free()
|
|
* pc->mem_cgroup = dead memcg
|
|
* add page to lru
|
|
*
|
|
* The bulk of the charges are still moved in offline_css() to
|
|
* avoid pinning a lot of pages in case a long-term reference
|
|
* like a swapout record is deferring the css_free() to long
|
|
* after offlining. But this makes sure we catch any charges
|
|
* made after offlining:
|
|
*/
|
|
mem_cgroup_reparent_charges(memcg);
|
|
|
|
memcg_destroy_kmem(memcg);
|
|
__mem_cgroup_free(memcg);
|
|
}
|
|
|
|
#ifdef CONFIG_MMU
|
|
/* Handlers for move charge at task migration. */
|
|
#define PRECHARGE_COUNT_AT_ONCE 256
|
|
static int mem_cgroup_do_precharge(unsigned long count)
|
|
{
|
|
int ret = 0;
|
|
int batch_count = PRECHARGE_COUNT_AT_ONCE;
|
|
struct mem_cgroup *memcg = mc.to;
|
|
|
|
if (mem_cgroup_is_root(memcg)) {
|
|
mc.precharge += count;
|
|
/* we don't need css_get for root */
|
|
return ret;
|
|
}
|
|
/* try to charge at once */
|
|
if (count > 1) {
|
|
struct res_counter *dummy;
|
|
/*
|
|
* "memcg" cannot be under rmdir() because we've already checked
|
|
* by cgroup_lock_live_cgroup() that it is not removed and we
|
|
* are still under the same cgroup_mutex. So we can postpone
|
|
* css_get().
|
|
*/
|
|
if (res_counter_charge(&memcg->res, PAGE_SIZE * count, &dummy))
|
|
goto one_by_one;
|
|
if (do_swap_account && res_counter_charge(&memcg->memsw,
|
|
PAGE_SIZE * count, &dummy)) {
|
|
res_counter_uncharge(&memcg->res, PAGE_SIZE * count);
|
|
goto one_by_one;
|
|
}
|
|
mc.precharge += count;
|
|
return ret;
|
|
}
|
|
one_by_one:
|
|
/* fall back to one by one charge */
|
|
while (count--) {
|
|
if (signal_pending(current)) {
|
|
ret = -EINTR;
|
|
break;
|
|
}
|
|
if (!batch_count--) {
|
|
batch_count = PRECHARGE_COUNT_AT_ONCE;
|
|
cond_resched();
|
|
}
|
|
ret = __mem_cgroup_try_charge(NULL,
|
|
GFP_KERNEL, 1, &memcg, false);
|
|
if (ret)
|
|
/* mem_cgroup_clear_mc() will do uncharge later */
|
|
return ret;
|
|
mc.precharge++;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* get_mctgt_type - get target type of moving charge
|
|
* @vma: the vma the pte to be checked belongs
|
|
* @addr: the address corresponding to the pte to be checked
|
|
* @ptent: the pte to be checked
|
|
* @target: the pointer the target page or swap ent will be stored(can be NULL)
|
|
*
|
|
* Returns
|
|
* 0(MC_TARGET_NONE): if the pte is not a target for move charge.
|
|
* 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
|
|
* move charge. if @target is not NULL, the page is stored in target->page
|
|
* with extra refcnt got(Callers should handle it).
|
|
* 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
|
|
* target for charge migration. if @target is not NULL, the entry is stored
|
|
* in target->ent.
|
|
*
|
|
* Called with pte lock held.
|
|
*/
|
|
union mc_target {
|
|
struct page *page;
|
|
swp_entry_t ent;
|
|
};
|
|
|
|
enum mc_target_type {
|
|
MC_TARGET_NONE = 0,
|
|
MC_TARGET_PAGE,
|
|
MC_TARGET_SWAP,
|
|
};
|
|
|
|
static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent)
|
|
{
|
|
struct page *page = vm_normal_page(vma, addr, ptent);
|
|
|
|
if (!page || !page_mapped(page))
|
|
return NULL;
|
|
if (PageAnon(page)) {
|
|
/* we don't move shared anon */
|
|
if (!move_anon())
|
|
return NULL;
|
|
} else if (!move_file())
|
|
/* we ignore mapcount for file pages */
|
|
return NULL;
|
|
if (!get_page_unless_zero(page))
|
|
return NULL;
|
|
|
|
return page;
|
|
}
|
|
|
|
#ifdef CONFIG_SWAP
|
|
static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent, swp_entry_t *entry)
|
|
{
|
|
struct page *page = NULL;
|
|
swp_entry_t ent = pte_to_swp_entry(ptent);
|
|
|
|
if (!move_anon() || non_swap_entry(ent))
|
|
return NULL;
|
|
/*
|
|
* Because lookup_swap_cache() updates some statistics counter,
|
|
* we call find_get_page() with swapper_space directly.
|
|
*/
|
|
page = find_get_page(swap_address_space(ent), ent.val);
|
|
if (do_swap_account)
|
|
entry->val = ent.val;
|
|
|
|
return page;
|
|
}
|
|
#else
|
|
static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent, swp_entry_t *entry)
|
|
{
|
|
return NULL;
|
|
}
|
|
#endif
|
|
|
|
static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent, swp_entry_t *entry)
|
|
{
|
|
struct page *page = NULL;
|
|
struct address_space *mapping;
|
|
pgoff_t pgoff;
|
|
|
|
if (!vma->vm_file) /* anonymous vma */
|
|
return NULL;
|
|
if (!move_file())
|
|
return NULL;
|
|
|
|
mapping = vma->vm_file->f_mapping;
|
|
if (pte_none(ptent))
|
|
pgoff = linear_page_index(vma, addr);
|
|
else /* pte_file(ptent) is true */
|
|
pgoff = pte_to_pgoff(ptent);
|
|
|
|
/* page is moved even if it's not RSS of this task(page-faulted). */
|
|
page = find_get_page(mapping, pgoff);
|
|
|
|
#ifdef CONFIG_SWAP
|
|
/* shmem/tmpfs may report page out on swap: account for that too. */
|
|
if (radix_tree_exceptional_entry(page)) {
|
|
swp_entry_t swap = radix_to_swp_entry(page);
|
|
if (do_swap_account)
|
|
*entry = swap;
|
|
page = find_get_page(swap_address_space(swap), swap.val);
|
|
}
|
|
#endif
|
|
return page;
|
|
}
|
|
|
|
static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent, union mc_target *target)
|
|
{
|
|
struct page *page = NULL;
|
|
struct page_cgroup *pc;
|
|
enum mc_target_type ret = MC_TARGET_NONE;
|
|
swp_entry_t ent = { .val = 0 };
|
|
|
|
if (pte_present(ptent))
|
|
page = mc_handle_present_pte(vma, addr, ptent);
|
|
else if (is_swap_pte(ptent))
|
|
page = mc_handle_swap_pte(vma, addr, ptent, &ent);
|
|
else if (pte_none(ptent) || pte_file(ptent))
|
|
page = mc_handle_file_pte(vma, addr, ptent, &ent);
|
|
|
|
if (!page && !ent.val)
|
|
return ret;
|
|
if (page) {
|
|
pc = lookup_page_cgroup(page);
|
|
/*
|
|
* Do only loose check w/o page_cgroup lock.
|
|
* mem_cgroup_move_account() checks the pc is valid or not under
|
|
* the lock.
|
|
*/
|
|
if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
|
|
ret = MC_TARGET_PAGE;
|
|
if (target)
|
|
target->page = page;
|
|
}
|
|
if (!ret || !target)
|
|
put_page(page);
|
|
}
|
|
/* There is a swap entry and a page doesn't exist or isn't charged */
|
|
if (ent.val && !ret &&
|
|
mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) {
|
|
ret = MC_TARGET_SWAP;
|
|
if (target)
|
|
target->ent = ent;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
/*
|
|
* We don't consider swapping or file mapped pages because THP does not
|
|
* support them for now.
|
|
* Caller should make sure that pmd_trans_huge(pmd) is true.
|
|
*/
|
|
static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
|
|
unsigned long addr, pmd_t pmd, union mc_target *target)
|
|
{
|
|
struct page *page = NULL;
|
|
struct page_cgroup *pc;
|
|
enum mc_target_type ret = MC_TARGET_NONE;
|
|
|
|
page = pmd_page(pmd);
|
|
VM_BUG_ON_PAGE(!page || !PageHead(page), page);
|
|
if (!move_anon())
|
|
return ret;
|
|
pc = lookup_page_cgroup(page);
|
|
if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
|
|
ret = MC_TARGET_PAGE;
|
|
if (target) {
|
|
get_page(page);
|
|
target->page = page;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
#else
|
|
static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
|
|
unsigned long addr, pmd_t pmd, union mc_target *target)
|
|
{
|
|
return MC_TARGET_NONE;
|
|
}
|
|
#endif
|
|
|
|
static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
|
|
unsigned long addr, unsigned long end,
|
|
struct mm_walk *walk)
|
|
{
|
|
struct vm_area_struct *vma = walk->private;
|
|
pte_t *pte;
|
|
spinlock_t *ptl;
|
|
|
|
if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
|
|
if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE)
|
|
mc.precharge += HPAGE_PMD_NR;
|
|
spin_unlock(ptl);
|
|
return 0;
|
|
}
|
|
|
|
if (pmd_trans_unstable(pmd))
|
|
return 0;
|
|
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
|
|
for (; addr != end; pte++, addr += PAGE_SIZE)
|
|
if (get_mctgt_type(vma, addr, *pte, NULL))
|
|
mc.precharge++; /* increment precharge temporarily */
|
|
pte_unmap_unlock(pte - 1, ptl);
|
|
cond_resched();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
|
|
{
|
|
unsigned long precharge;
|
|
struct vm_area_struct *vma;
|
|
|
|
down_read(&mm->mmap_sem);
|
|
for (vma = mm->mmap; vma; vma = vma->vm_next) {
|
|
struct mm_walk mem_cgroup_count_precharge_walk = {
|
|
.pmd_entry = mem_cgroup_count_precharge_pte_range,
|
|
.mm = mm,
|
|
.private = vma,
|
|
};
|
|
if (is_vm_hugetlb_page(vma))
|
|
continue;
|
|
walk_page_range(vma->vm_start, vma->vm_end,
|
|
&mem_cgroup_count_precharge_walk);
|
|
}
|
|
up_read(&mm->mmap_sem);
|
|
|
|
precharge = mc.precharge;
|
|
mc.precharge = 0;
|
|
|
|
return precharge;
|
|
}
|
|
|
|
static int mem_cgroup_precharge_mc(struct mm_struct *mm)
|
|
{
|
|
unsigned long precharge = mem_cgroup_count_precharge(mm);
|
|
|
|
VM_BUG_ON(mc.moving_task);
|
|
mc.moving_task = current;
|
|
return mem_cgroup_do_precharge(precharge);
|
|
}
|
|
|
|
/* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
|
|
static void __mem_cgroup_clear_mc(void)
|
|
{
|
|
struct mem_cgroup *from = mc.from;
|
|
struct mem_cgroup *to = mc.to;
|
|
int i;
|
|
|
|
/* we must uncharge all the leftover precharges from mc.to */
|
|
if (mc.precharge) {
|
|
__mem_cgroup_cancel_charge(mc.to, mc.precharge);
|
|
mc.precharge = 0;
|
|
}
|
|
/*
|
|
* we didn't uncharge from mc.from at mem_cgroup_move_account(), so
|
|
* we must uncharge here.
|
|
*/
|
|
if (mc.moved_charge) {
|
|
__mem_cgroup_cancel_charge(mc.from, mc.moved_charge);
|
|
mc.moved_charge = 0;
|
|
}
|
|
/* we must fixup refcnts and charges */
|
|
if (mc.moved_swap) {
|
|
/* uncharge swap account from the old cgroup */
|
|
if (!mem_cgroup_is_root(mc.from))
|
|
res_counter_uncharge(&mc.from->memsw,
|
|
PAGE_SIZE * mc.moved_swap);
|
|
|
|
for (i = 0; i < mc.moved_swap; i++)
|
|
css_put(&mc.from->css);
|
|
|
|
if (!mem_cgroup_is_root(mc.to)) {
|
|
/*
|
|
* we charged both to->res and to->memsw, so we should
|
|
* uncharge to->res.
|
|
*/
|
|
res_counter_uncharge(&mc.to->res,
|
|
PAGE_SIZE * mc.moved_swap);
|
|
}
|
|
/* we've already done css_get(mc.to) */
|
|
mc.moved_swap = 0;
|
|
}
|
|
memcg_oom_recover(from);
|
|
memcg_oom_recover(to);
|
|
wake_up_all(&mc.waitq);
|
|
}
|
|
|
|
static void mem_cgroup_clear_mc(void)
|
|
{
|
|
struct mem_cgroup *from = mc.from;
|
|
|
|
/*
|
|
* we must clear moving_task before waking up waiters at the end of
|
|
* task migration.
|
|
*/
|
|
mc.moving_task = NULL;
|
|
__mem_cgroup_clear_mc();
|
|
spin_lock(&mc.lock);
|
|
mc.from = NULL;
|
|
mc.to = NULL;
|
|
spin_unlock(&mc.lock);
|
|
mem_cgroup_end_move(from);
|
|
}
|
|
|
|
static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
struct task_struct *p = cgroup_taskset_first(tset);
|
|
int ret = 0;
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
unsigned long move_charge_at_immigrate;
|
|
|
|
/*
|
|
* We are now commited to this value whatever it is. Changes in this
|
|
* tunable will only affect upcoming migrations, not the current one.
|
|
* So we need to save it, and keep it going.
|
|
*/
|
|
move_charge_at_immigrate = memcg->move_charge_at_immigrate;
|
|
if (move_charge_at_immigrate) {
|
|
struct mm_struct *mm;
|
|
struct mem_cgroup *from = mem_cgroup_from_task(p);
|
|
|
|
VM_BUG_ON(from == memcg);
|
|
|
|
mm = get_task_mm(p);
|
|
if (!mm)
|
|
return 0;
|
|
/* We move charges only when we move a owner of the mm */
|
|
if (mm->owner == p) {
|
|
VM_BUG_ON(mc.from);
|
|
VM_BUG_ON(mc.to);
|
|
VM_BUG_ON(mc.precharge);
|
|
VM_BUG_ON(mc.moved_charge);
|
|
VM_BUG_ON(mc.moved_swap);
|
|
mem_cgroup_start_move(from);
|
|
spin_lock(&mc.lock);
|
|
mc.from = from;
|
|
mc.to = memcg;
|
|
mc.immigrate_flags = move_charge_at_immigrate;
|
|
spin_unlock(&mc.lock);
|
|
/* We set mc.moving_task later */
|
|
|
|
ret = mem_cgroup_precharge_mc(mm);
|
|
if (ret)
|
|
mem_cgroup_clear_mc();
|
|
}
|
|
mmput(mm);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
mem_cgroup_clear_mc();
|
|
}
|
|
|
|
static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
|
|
unsigned long addr, unsigned long end,
|
|
struct mm_walk *walk)
|
|
{
|
|
int ret = 0;
|
|
struct vm_area_struct *vma = walk->private;
|
|
pte_t *pte;
|
|
spinlock_t *ptl;
|
|
enum mc_target_type target_type;
|
|
union mc_target target;
|
|
struct page *page;
|
|
struct page_cgroup *pc;
|
|
|
|
/*
|
|
* We don't take compound_lock() here but no race with splitting thp
|
|
* happens because:
|
|
* - if pmd_trans_huge_lock() returns 1, the relevant thp is not
|
|
* under splitting, which means there's no concurrent thp split,
|
|
* - if another thread runs into split_huge_page() just after we
|
|
* entered this if-block, the thread must wait for page table lock
|
|
* to be unlocked in __split_huge_page_splitting(), where the main
|
|
* part of thp split is not executed yet.
|
|
*/
|
|
if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
|
|
if (mc.precharge < HPAGE_PMD_NR) {
|
|
spin_unlock(ptl);
|
|
return 0;
|
|
}
|
|
target_type = get_mctgt_type_thp(vma, addr, *pmd, &target);
|
|
if (target_type == MC_TARGET_PAGE) {
|
|
page = target.page;
|
|
if (!isolate_lru_page(page)) {
|
|
pc = lookup_page_cgroup(page);
|
|
if (!mem_cgroup_move_account(page, HPAGE_PMD_NR,
|
|
pc, mc.from, mc.to)) {
|
|
mc.precharge -= HPAGE_PMD_NR;
|
|
mc.moved_charge += HPAGE_PMD_NR;
|
|
}
|
|
putback_lru_page(page);
|
|
}
|
|
put_page(page);
|
|
}
|
|
spin_unlock(ptl);
|
|
return 0;
|
|
}
|
|
|
|
if (pmd_trans_unstable(pmd))
|
|
return 0;
|
|
retry:
|
|
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
|
|
for (; addr != end; addr += PAGE_SIZE) {
|
|
pte_t ptent = *(pte++);
|
|
swp_entry_t ent;
|
|
|
|
if (!mc.precharge)
|
|
break;
|
|
|
|
switch (get_mctgt_type(vma, addr, ptent, &target)) {
|
|
case MC_TARGET_PAGE:
|
|
page = target.page;
|
|
if (isolate_lru_page(page))
|
|
goto put;
|
|
pc = lookup_page_cgroup(page);
|
|
if (!mem_cgroup_move_account(page, 1, pc,
|
|
mc.from, mc.to)) {
|
|
mc.precharge--;
|
|
/* we uncharge from mc.from later. */
|
|
mc.moved_charge++;
|
|
}
|
|
putback_lru_page(page);
|
|
put: /* get_mctgt_type() gets the page */
|
|
put_page(page);
|
|
break;
|
|
case MC_TARGET_SWAP:
|
|
ent = target.ent;
|
|
if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) {
|
|
mc.precharge--;
|
|
/* we fixup refcnts and charges later. */
|
|
mc.moved_swap++;
|
|
}
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
pte_unmap_unlock(pte - 1, ptl);
|
|
cond_resched();
|
|
|
|
if (addr != end) {
|
|
/*
|
|
* We have consumed all precharges we got in can_attach().
|
|
* We try charge one by one, but don't do any additional
|
|
* charges to mc.to if we have failed in charge once in attach()
|
|
* phase.
|
|
*/
|
|
ret = mem_cgroup_do_precharge(1);
|
|
if (!ret)
|
|
goto retry;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void mem_cgroup_move_charge(struct mm_struct *mm)
|
|
{
|
|
struct vm_area_struct *vma;
|
|
|
|
lru_add_drain_all();
|
|
retry:
|
|
if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
|
|
/*
|
|
* Someone who are holding the mmap_sem might be waiting in
|
|
* waitq. So we cancel all extra charges, wake up all waiters,
|
|
* and retry. Because we cancel precharges, we might not be able
|
|
* to move enough charges, but moving charge is a best-effort
|
|
* feature anyway, so it wouldn't be a big problem.
|
|
*/
|
|
__mem_cgroup_clear_mc();
|
|
cond_resched();
|
|
goto retry;
|
|
}
|
|
for (vma = mm->mmap; vma; vma = vma->vm_next) {
|
|
int ret;
|
|
struct mm_walk mem_cgroup_move_charge_walk = {
|
|
.pmd_entry = mem_cgroup_move_charge_pte_range,
|
|
.mm = mm,
|
|
.private = vma,
|
|
};
|
|
if (is_vm_hugetlb_page(vma))
|
|
continue;
|
|
ret = walk_page_range(vma->vm_start, vma->vm_end,
|
|
&mem_cgroup_move_charge_walk);
|
|
if (ret)
|
|
/*
|
|
* means we have consumed all precharges and failed in
|
|
* doing additional charge. Just abandon here.
|
|
*/
|
|
break;
|
|
}
|
|
up_read(&mm->mmap_sem);
|
|
}
|
|
|
|
static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
struct task_struct *p = cgroup_taskset_first(tset);
|
|
struct mm_struct *mm = get_task_mm(p);
|
|
|
|
if (mm) {
|
|
if (mc.to)
|
|
mem_cgroup_move_charge(mm);
|
|
mmput(mm);
|
|
}
|
|
if (mc.to)
|
|
mem_cgroup_clear_mc();
|
|
}
|
|
#else /* !CONFIG_MMU */
|
|
static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
return 0;
|
|
}
|
|
static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
}
|
|
static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Cgroup retains root cgroups across [un]mount cycles making it necessary
|
|
* to verify sane_behavior flag on each mount attempt.
|
|
*/
|
|
static void mem_cgroup_bind(struct cgroup_subsys_state *root_css)
|
|
{
|
|
/*
|
|
* use_hierarchy is forced with sane_behavior. cgroup core
|
|
* guarantees that @root doesn't have any children, so turning it
|
|
* on for the root memcg is enough.
|
|
*/
|
|
if (cgroup_sane_behavior(root_css->cgroup))
|
|
mem_cgroup_from_css(root_css)->use_hierarchy = true;
|
|
}
|
|
|
|
struct cgroup_subsys mem_cgroup_subsys = {
|
|
.name = "memory",
|
|
.subsys_id = mem_cgroup_subsys_id,
|
|
.css_alloc = mem_cgroup_css_alloc,
|
|
.css_online = mem_cgroup_css_online,
|
|
.css_offline = mem_cgroup_css_offline,
|
|
.css_free = mem_cgroup_css_free,
|
|
.can_attach = mem_cgroup_can_attach,
|
|
.cancel_attach = mem_cgroup_cancel_attach,
|
|
.attach = mem_cgroup_move_task,
|
|
.bind = mem_cgroup_bind,
|
|
.base_cftypes = mem_cgroup_files,
|
|
.early_init = 0,
|
|
};
|
|
|
|
#ifdef CONFIG_MEMCG_SWAP
|
|
static int __init enable_swap_account(char *s)
|
|
{
|
|
if (!strcmp(s, "1"))
|
|
really_do_swap_account = 1;
|
|
else if (!strcmp(s, "0"))
|
|
really_do_swap_account = 0;
|
|
return 1;
|
|
}
|
|
__setup("swapaccount=", enable_swap_account);
|
|
|
|
static void __init memsw_file_init(void)
|
|
{
|
|
WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys, memsw_cgroup_files));
|
|
}
|
|
|
|
static void __init enable_swap_cgroup(void)
|
|
{
|
|
if (!mem_cgroup_disabled() && really_do_swap_account) {
|
|
do_swap_account = 1;
|
|
memsw_file_init();
|
|
}
|
|
}
|
|
|
|
#else
|
|
static void __init enable_swap_cgroup(void)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* subsys_initcall() for memory controller.
|
|
*
|
|
* Some parts like hotcpu_notifier() have to be initialized from this context
|
|
* because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
|
|
* everything that doesn't depend on a specific mem_cgroup structure should
|
|
* be initialized from here.
|
|
*/
|
|
static int __init mem_cgroup_init(void)
|
|
{
|
|
hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
|
|
enable_swap_cgroup();
|
|
mem_cgroup_soft_limit_tree_init();
|
|
memcg_stock_init();
|
|
return 0;
|
|
}
|
|
subsys_initcall(mem_cgroup_init);
|