![Glauber Costa](/assets/img/avatar_default.png)
Although only used currently for tcp sockets, this function
is now used in common sock code (for sock_clone())
Commit 475f1b5264
moved the
declaration of sock_update_clone() to inside sock.c, but
this only fixes the problem when CONFIG_CGROUP_MEM_RES_CTLR_KMEM
is also not defined.
This patch here is verified to fix both problems, although
reverting the previous one is not necessary.
Signed-off-by: Glauber Costa <glommer@parallels.com>
CC: David S. Miller <davem@davemloft.net>
CC: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
5518 lines
142 KiB
C
5518 lines
142 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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* 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/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/vmalloc.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 "internal.h"
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#include <net/sock.h>
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#include <net/tcp_memcontrol.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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#define MEM_CGROUP_RECLAIM_RETRIES 5
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struct mem_cgroup *root_mem_cgroup __read_mostly;
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#ifdef CONFIG_CGROUP_MEM_RES_CTLR_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_CGROUP_MEM_RES_CTLR_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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/*
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* Statistics for memory cgroup.
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*/
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enum mem_cgroup_stat_index {
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/*
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* For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
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*/
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MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */
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MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */
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MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */
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MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */
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MEM_CGROUP_STAT_DATA, /* end of data requires synchronization */
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MEM_CGROUP_ON_MOVE, /* someone is moving account between groups */
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MEM_CGROUP_STAT_NSTATS,
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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_COUNT, /* # of pages paged in/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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/*
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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 targets[MEM_CGROUP_NTARGETS];
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};
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struct mem_cgroup_reclaim_iter {
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/* css_id of the last scanned hierarchy member */
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int position;
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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 count[NR_LRU_LISTS];
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struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1];
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struct zone_reclaim_stat reclaim_stat;
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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 *mem; /* Back pointer, we cannot */
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/* use container_of */
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};
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/* Macro for accessing counter */
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#define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
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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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struct mem_cgroup_lru_info {
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struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
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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 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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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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/*
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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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* Per cgroup active and inactive list, similar to the
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* per zone LRU lists.
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*/
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struct mem_cgroup_lru_info info;
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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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/*
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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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bool oom_lock;
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atomic_t under_oom;
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atomic_t refcnt;
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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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* percpu counter.
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*/
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struct mem_cgroup_stat_cpu *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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#ifdef CONFIG_INET
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struct tcp_memcontrol tcp_mem;
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#endif
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};
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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" is treated as a
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* 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 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,
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&mc.to->move_charge_at_immigrate);
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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,
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&mc.to->move_charge_at_immigrate);
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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_MAPPED,
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MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */
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MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */
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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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#define _MEM (0)
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#define _MEMSWAP (1)
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#define _OOM_TYPE (2)
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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
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#define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
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#define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
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#define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
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static void mem_cgroup_get(struct mem_cgroup *memcg);
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static void mem_cgroup_put(struct mem_cgroup *memcg);
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/* Writing them here to avoid exposing memcg's inner layout */
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#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
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#include <net/sock.h>
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#include <net/ip.h>
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static bool mem_cgroup_is_root(struct mem_cgroup *memcg);
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void sock_update_memcg(struct sock *sk)
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{
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if (static_branch(&memcg_socket_limit_enabled)) {
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struct mem_cgroup *memcg;
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BUG_ON(!sk->sk_prot->proto_cgroup);
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/* Socket cloning can throw us here with sk_cgrp already
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* filled. It won't however, necessarily happen from
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* process context. So the test for root memcg given
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* the current task's memcg won't help us in this case.
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*
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* Respecting the original socket's memcg is a better
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* decision in this case.
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*/
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if (sk->sk_cgrp) {
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BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg));
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mem_cgroup_get(sk->sk_cgrp->memcg);
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return;
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}
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rcu_read_lock();
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memcg = mem_cgroup_from_task(current);
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if (!mem_cgroup_is_root(memcg)) {
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mem_cgroup_get(memcg);
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sk->sk_cgrp = sk->sk_prot->proto_cgroup(memcg);
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}
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rcu_read_unlock();
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}
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}
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EXPORT_SYMBOL(sock_update_memcg);
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void sock_release_memcg(struct sock *sk)
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{
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if (static_branch(&memcg_socket_limit_enabled) && sk->sk_cgrp) {
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struct mem_cgroup *memcg;
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WARN_ON(!sk->sk_cgrp->memcg);
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memcg = sk->sk_cgrp->memcg;
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mem_cgroup_put(memcg);
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}
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}
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#ifdef CONFIG_INET
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struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
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{
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if (!memcg || mem_cgroup_is_root(memcg))
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return NULL;
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return &memcg->tcp_mem.cg_proto;
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}
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EXPORT_SYMBOL(tcp_proto_cgroup);
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#endif /* CONFIG_INET */
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#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
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static void drain_all_stock_async(struct mem_cgroup *memcg);
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static struct mem_cgroup_per_zone *
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mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid)
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{
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return &memcg->info.nodeinfo[nid]->zoneinfo[zid];
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}
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struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg)
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{
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return &memcg->css;
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}
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static struct mem_cgroup_per_zone *
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page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page)
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{
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int nid = page_to_nid(page);
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int zid = page_zonenum(page);
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return mem_cgroup_zoneinfo(memcg, nid, zid);
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}
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static struct mem_cgroup_tree_per_zone *
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soft_limit_tree_node_zone(int nid, int zid)
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{
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return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
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}
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static struct mem_cgroup_tree_per_zone *
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soft_limit_tree_from_page(struct page *page)
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{
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int nid = page_to_nid(page);
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int zid = page_zonenum(page);
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return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
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}
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static void
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__mem_cgroup_insert_exceeded(struct mem_cgroup *memcg,
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struct mem_cgroup_per_zone *mz,
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struct mem_cgroup_tree_per_zone *mctz,
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unsigned long long new_usage_in_excess)
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{
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struct rb_node **p = &mctz->rb_root.rb_node;
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struct rb_node *parent = NULL;
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struct mem_cgroup_per_zone *mz_node;
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|
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->mem, mz, mctz);
|
|
if (!res_counter_soft_limit_excess(&mz->mem->res) ||
|
|
!css_tryget(&mz->mem->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_SWAPOUT], val);
|
|
}
|
|
|
|
static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg,
|
|
enum mem_cgroup_events_index idx)
|
|
{
|
|
unsigned long val = 0;
|
|
int cpu;
|
|
|
|
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
|
|
return val;
|
|
}
|
|
|
|
static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
|
|
bool file, int nr_pages)
|
|
{
|
|
preempt_disable();
|
|
|
|
if (file)
|
|
__this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE],
|
|
nr_pages);
|
|
else
|
|
__this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS],
|
|
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->events[MEM_CGROUP_EVENTS_COUNT], nr_pages);
|
|
|
|
preempt_enable();
|
|
}
|
|
|
|
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 l;
|
|
unsigned long ret = 0;
|
|
|
|
mz = mem_cgroup_zoneinfo(memcg, nid, zid);
|
|
|
|
for_each_lru(l) {
|
|
if (BIT(l) & lru_mask)
|
|
ret += MEM_CGROUP_ZSTAT(mz, l);
|
|
}
|
|
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_HIGH_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->events[MEM_CGROUP_EVENTS_COUNT]);
|
|
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, do_numainfo;
|
|
|
|
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_cont(struct cgroup *cont)
|
|
{
|
|
return container_of(cgroup_subsys_state(cont,
|
|
mem_cgroup_subsys_id), struct mem_cgroup,
|
|
css);
|
|
}
|
|
|
|
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 container_of(task_subsys_state(p, mem_cgroup_subsys_id),
|
|
struct mem_cgroup, css);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
int id = 0;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return NULL;
|
|
|
|
if (!root)
|
|
root = root_mem_cgroup;
|
|
|
|
if (prev && !reclaim)
|
|
id = css_id(&prev->css);
|
|
|
|
if (prev && prev != root)
|
|
css_put(&prev->css);
|
|
|
|
if (!root->use_hierarchy && root != root_mem_cgroup) {
|
|
if (prev)
|
|
return NULL;
|
|
return root;
|
|
}
|
|
|
|
while (!memcg) {
|
|
struct mem_cgroup_reclaim_iter *uninitialized_var(iter);
|
|
struct cgroup_subsys_state *css;
|
|
|
|
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)
|
|
return NULL;
|
|
id = iter->position;
|
|
}
|
|
|
|
rcu_read_lock();
|
|
css = css_get_next(&mem_cgroup_subsys, id + 1, &root->css, &id);
|
|
if (css) {
|
|
if (css == &root->css || css_tryget(css))
|
|
memcg = container_of(css,
|
|
struct mem_cgroup, css);
|
|
} else
|
|
id = 0;
|
|
rcu_read_unlock();
|
|
|
|
if (reclaim) {
|
|
iter->position = id;
|
|
if (!css)
|
|
iter->generation++;
|
|
else if (!prev && memcg)
|
|
reclaim->generation = iter->generation;
|
|
}
|
|
|
|
if (prev && !css)
|
|
return NULL;
|
|
}
|
|
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))
|
|
|
|
static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
|
|
{
|
|
return (memcg == root_mem_cgroup);
|
|
}
|
|
|
|
void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
|
|
if (!mm)
|
|
return;
|
|
|
|
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
|
|
* @mem: 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;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return &zone->lruvec;
|
|
|
|
mz = mem_cgroup_zoneinfo(memcg, zone_to_nid(zone), zone_idx(zone));
|
|
return &mz->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_lru_add_list - account for adding an lru page and return lruvec
|
|
* @zone: zone of the page
|
|
* @page: the page
|
|
* @lru: current lru
|
|
*
|
|
* This function accounts for @page being added to @lru, and returns
|
|
* the lruvec for the given @zone and the memcg @page is charged to.
|
|
*
|
|
* The callsite is then responsible for physically linking the page to
|
|
* the returned lruvec->lists[@lru].
|
|
*/
|
|
struct lruvec *mem_cgroup_lru_add_list(struct zone *zone, struct page *page,
|
|
enum lru_list lru)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct mem_cgroup *memcg;
|
|
struct page_cgroup *pc;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return &zone->lruvec;
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
memcg = pc->mem_cgroup;
|
|
mz = page_cgroup_zoneinfo(memcg, page);
|
|
/* compound_order() is stabilized through lru_lock */
|
|
MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
|
|
return &mz->lruvec;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_lru_del_list - account for removing an lru page
|
|
* @page: the page
|
|
* @lru: target lru
|
|
*
|
|
* This function accounts for @page being removed from @lru.
|
|
*
|
|
* The callsite is then responsible for physically unlinking
|
|
* @page->lru.
|
|
*/
|
|
void mem_cgroup_lru_del_list(struct page *page, enum lru_list lru)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct mem_cgroup *memcg;
|
|
struct page_cgroup *pc;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
memcg = pc->mem_cgroup;
|
|
VM_BUG_ON(!memcg);
|
|
mz = page_cgroup_zoneinfo(memcg, page);
|
|
/* huge page split is done under lru_lock. so, we have no races. */
|
|
VM_BUG_ON(MEM_CGROUP_ZSTAT(mz, lru) < (1 << compound_order(page)));
|
|
MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page);
|
|
}
|
|
|
|
void mem_cgroup_lru_del(struct page *page)
|
|
{
|
|
mem_cgroup_lru_del_list(page, page_lru(page));
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_lru_move_lists - account for moving a page between lrus
|
|
* @zone: zone of the page
|
|
* @page: the page
|
|
* @from: current lru
|
|
* @to: target lru
|
|
*
|
|
* This function accounts for @page being moved between the lrus @from
|
|
* and @to, and returns the lruvec for the given @zone and the memcg
|
|
* @page is charged to.
|
|
*
|
|
* The callsite is then responsible for physically relinking
|
|
* @page->lru to the returned lruvec->lists[@to].
|
|
*/
|
|
struct lruvec *mem_cgroup_lru_move_lists(struct zone *zone,
|
|
struct page *page,
|
|
enum lru_list from,
|
|
enum lru_list to)
|
|
{
|
|
/* XXX: Optimize this, especially for @from == @to */
|
|
mem_cgroup_lru_del_list(page, from);
|
|
return mem_cgroup_lru_add_list(zone, page, to);
|
|
}
|
|
|
|
/*
|
|
* Checks whether given mem is same or in the root_mem_cgroup's
|
|
* hierarchy subtree
|
|
*/
|
|
static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
|
|
struct mem_cgroup *memcg)
|
|
{
|
|
if (root_memcg != memcg) {
|
|
return (root_memcg->use_hierarchy &&
|
|
css_is_ancestor(&memcg->css, &root_memcg->css));
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg)
|
|
{
|
|
int ret;
|
|
struct mem_cgroup *curr = NULL;
|
|
struct task_struct *p;
|
|
|
|
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.
|
|
*/
|
|
task_lock(task);
|
|
curr = mem_cgroup_from_task(task);
|
|
if (curr)
|
|
css_get(&curr->css);
|
|
task_unlock(task);
|
|
}
|
|
if (!curr)
|
|
return 0;
|
|
/*
|
|
* 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 mem_cgroup *memcg, struct zone *zone)
|
|
{
|
|
unsigned long inactive_ratio;
|
|
int nid = zone_to_nid(zone);
|
|
int zid = zone_idx(zone);
|
|
unsigned long inactive;
|
|
unsigned long active;
|
|
unsigned long gb;
|
|
|
|
inactive = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid,
|
|
BIT(LRU_INACTIVE_ANON));
|
|
active = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid,
|
|
BIT(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;
|
|
}
|
|
|
|
int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg, struct zone *zone)
|
|
{
|
|
unsigned long active;
|
|
unsigned long inactive;
|
|
int zid = zone_idx(zone);
|
|
int nid = zone_to_nid(zone);
|
|
|
|
inactive = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid,
|
|
BIT(LRU_INACTIVE_FILE));
|
|
active = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid,
|
|
BIT(LRU_ACTIVE_FILE));
|
|
|
|
return (active > inactive);
|
|
}
|
|
|
|
struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
|
|
struct zone *zone)
|
|
{
|
|
int nid = zone_to_nid(zone);
|
|
int zid = zone_idx(zone);
|
|
struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
|
|
|
|
return &mz->reclaim_stat;
|
|
}
|
|
|
|
struct zone_reclaim_stat *
|
|
mem_cgroup_get_reclaim_stat_from_page(struct page *page)
|
|
{
|
|
struct page_cgroup *pc;
|
|
struct mem_cgroup_per_zone *mz;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return NULL;
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
if (!PageCgroupUsed(pc))
|
|
return NULL;
|
|
/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
|
|
smp_rmb();
|
|
mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
|
|
return &mz->reclaim_stat;
|
|
}
|
|
|
|
#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
|
|
* @mem: 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)
|
|
{
|
|
struct cgroup *cgrp = memcg->css.cgroup;
|
|
|
|
/* root ? */
|
|
if (cgrp->parent == NULL)
|
|
return vm_swappiness;
|
|
|
|
return memcg->swappiness;
|
|
}
|
|
|
|
static void mem_cgroup_start_move(struct mem_cgroup *memcg)
|
|
{
|
|
int cpu;
|
|
|
|
get_online_cpus();
|
|
spin_lock(&memcg->pcp_counter_lock);
|
|
for_each_online_cpu(cpu)
|
|
per_cpu(memcg->stat->count[MEM_CGROUP_ON_MOVE], cpu) += 1;
|
|
memcg->nocpu_base.count[MEM_CGROUP_ON_MOVE] += 1;
|
|
spin_unlock(&memcg->pcp_counter_lock);
|
|
put_online_cpus();
|
|
|
|
synchronize_rcu();
|
|
}
|
|
|
|
static void mem_cgroup_end_move(struct mem_cgroup *memcg)
|
|
{
|
|
int cpu;
|
|
|
|
if (!memcg)
|
|
return;
|
|
get_online_cpus();
|
|
spin_lock(&memcg->pcp_counter_lock);
|
|
for_each_online_cpu(cpu)
|
|
per_cpu(memcg->stat->count[MEM_CGROUP_ON_MOVE], cpu) -= 1;
|
|
memcg->nocpu_base.count[MEM_CGROUP_ON_MOVE] -= 1;
|
|
spin_unlock(&memcg->pcp_counter_lock);
|
|
put_online_cpus();
|
|
}
|
|
/*
|
|
* 2 routines for checking "mem" is under move_account() or not.
|
|
*
|
|
* mem_cgroup_stealed() - checking a cgroup is mc.from or not. This is used
|
|
* for avoiding race 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_stealed(struct mem_cgroup *memcg)
|
|
{
|
|
VM_BUG_ON(!rcu_read_lock_held());
|
|
return this_cpu_read(memcg->stat->count[MEM_CGROUP_ON_MOVE]) > 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;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode.
|
|
* @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)
|
|
{
|
|
struct cgroup *task_cgrp;
|
|
struct cgroup *mem_cgrp;
|
|
/*
|
|
* Need a buffer in BSS, can't rely on allocations. The code relies
|
|
* on the assumption that OOM is serialized for memory controller.
|
|
* If this assumption is broken, revisit this code.
|
|
*/
|
|
static char memcg_name[PATH_MAX];
|
|
int ret;
|
|
|
|
if (!memcg || !p)
|
|
return;
|
|
|
|
|
|
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();
|
|
|
|
printk(KERN_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
|
|
*/
|
|
printk(KERN_CONT " as a result of limit of %s\n", memcg_name);
|
|
done:
|
|
|
|
printk(KERN_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));
|
|
printk(KERN_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));
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
|
|
{
|
|
u64 limit;
|
|
u64 memsw;
|
|
|
|
limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
|
|
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.
|
|
*/
|
|
return min(limit, memsw);
|
|
}
|
|
|
|
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
|
|
* @mem: 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_HIGH_MEMORY];
|
|
|
|
for_each_node_mask(nid, node_states[N_HIGH_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.
|
|
*/
|
|
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_HIGH_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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Check OOM-Killer is already running under our hierarchy.
|
|
* If someone is running, return false.
|
|
* Has to be called with memcg_oom_lock
|
|
*/
|
|
static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter, *failed = NULL;
|
|
|
|
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)
|
|
return true;
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Has to be called with memcg_oom_lock
|
|
*/
|
|
static int mem_cgroup_oom_unlock(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
iter->oom_lock = false;
|
|
return 0;
|
|
}
|
|
|
|
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 DEFINE_SPINLOCK(memcg_oom_lock);
|
|
static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
|
|
|
|
struct oom_wait_info {
|
|
struct mem_cgroup *mem;
|
|
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,
|
|
*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->mem;
|
|
|
|
/*
|
|
* Both of oom_wait_info->mem and wake_mem 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)
|
|
{
|
|
/* 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);
|
|
}
|
|
|
|
/*
|
|
* try to call OOM killer. returns false if we should exit memory-reclaim loop.
|
|
*/
|
|
bool mem_cgroup_handle_oom(struct mem_cgroup *memcg, gfp_t mask)
|
|
{
|
|
struct oom_wait_info owait;
|
|
bool locked, need_to_kill;
|
|
|
|
owait.mem = memcg;
|
|
owait.wait.flags = 0;
|
|
owait.wait.func = memcg_oom_wake_function;
|
|
owait.wait.private = current;
|
|
INIT_LIST_HEAD(&owait.wait.task_list);
|
|
need_to_kill = true;
|
|
mem_cgroup_mark_under_oom(memcg);
|
|
|
|
/* At first, try to OOM lock hierarchy under memcg.*/
|
|
spin_lock(&memcg_oom_lock);
|
|
locked = mem_cgroup_oom_lock(memcg);
|
|
/*
|
|
* Even if signal_pending(), we can't quit charge() loop without
|
|
* accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL
|
|
* under OOM is always welcomed, use TASK_KILLABLE here.
|
|
*/
|
|
prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
|
|
if (!locked || memcg->oom_kill_disable)
|
|
need_to_kill = false;
|
|
if (locked)
|
|
mem_cgroup_oom_notify(memcg);
|
|
spin_unlock(&memcg_oom_lock);
|
|
|
|
if (need_to_kill) {
|
|
finish_wait(&memcg_oom_waitq, &owait.wait);
|
|
mem_cgroup_out_of_memory(memcg, mask);
|
|
} else {
|
|
schedule();
|
|
finish_wait(&memcg_oom_waitq, &owait.wait);
|
|
}
|
|
spin_lock(&memcg_oom_lock);
|
|
if (locked)
|
|
mem_cgroup_oom_unlock(memcg);
|
|
memcg_wakeup_oom(memcg);
|
|
spin_unlock(&memcg_oom_lock);
|
|
|
|
mem_cgroup_unmark_under_oom(memcg);
|
|
|
|
if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current))
|
|
return false;
|
|
/* Give chance to dying process */
|
|
schedule_timeout_uninterruptible(1);
|
|
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 MEM_CGROUP_ON_MOVE percpu value and detect there are
|
|
* possibility of race condition. If there is, we take a lock.
|
|
*/
|
|
|
|
void mem_cgroup_update_page_stat(struct page *page,
|
|
enum mem_cgroup_page_stat_item idx, int val)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
struct page_cgroup *pc = lookup_page_cgroup(page);
|
|
bool need_unlock = false;
|
|
unsigned long uninitialized_var(flags);
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
rcu_read_lock();
|
|
memcg = pc->mem_cgroup;
|
|
if (unlikely(!memcg || !PageCgroupUsed(pc)))
|
|
goto out;
|
|
/* pc->mem_cgroup is unstable ? */
|
|
if (unlikely(mem_cgroup_stealed(memcg)) || PageTransHuge(page)) {
|
|
/* take a lock against to access pc->mem_cgroup */
|
|
move_lock_page_cgroup(pc, &flags);
|
|
need_unlock = true;
|
|
memcg = pc->mem_cgroup;
|
|
if (!memcg || !PageCgroupUsed(pc))
|
|
goto out;
|
|
}
|
|
|
|
switch (idx) {
|
|
case MEMCG_NR_FILE_MAPPED:
|
|
if (val > 0)
|
|
SetPageCgroupFileMapped(pc);
|
|
else if (!page_mapped(page))
|
|
ClearPageCgroupFileMapped(pc);
|
|
idx = MEM_CGROUP_STAT_FILE_MAPPED;
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
this_cpu_add(memcg->stat->count[idx], val);
|
|
|
|
out:
|
|
if (unlikely(need_unlock))
|
|
move_unlock_page_cgroup(pc, &flags);
|
|
rcu_read_unlock();
|
|
return;
|
|
}
|
|
EXPORT_SYMBOL(mem_cgroup_update_page_stat);
|
|
|
|
/*
|
|
* 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);
|
|
|
|
/*
|
|
* Try to consume stocked charge on this cpu. If success, one page is consumed
|
|
* from local stock and true is returned. If the stock is 0 or charges from a
|
|
* cgroup which is not current target, returns false. This stock will be
|
|
* refilled.
|
|
*/
|
|
static bool consume_stock(struct mem_cgroup *memcg)
|
|
{
|
|
struct memcg_stock_pcp *stock;
|
|
bool ret = true;
|
|
|
|
stock = &get_cpu_var(memcg_stock);
|
|
if (memcg == stock->cached && stock->nr_pages)
|
|
stock->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);
|
|
}
|
|
|
|
/*
|
|
* 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_DATA; 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;
|
|
}
|
|
/* need to clear ON_MOVE value, works as a kind of lock. */
|
|
per_cpu(memcg->stat->count[MEM_CGROUP_ON_MOVE], cpu) = 0;
|
|
spin_unlock(&memcg->pcp_counter_lock);
|
|
}
|
|
|
|
static void synchronize_mem_cgroup_on_move(struct mem_cgroup *memcg, int cpu)
|
|
{
|
|
int idx = MEM_CGROUP_ON_MOVE;
|
|
|
|
spin_lock(&memcg->pcp_counter_lock);
|
|
per_cpu(memcg->stat->count[idx], cpu) = memcg->nocpu_base.count[idx];
|
|
spin_unlock(&memcg->pcp_counter_lock);
|
|
}
|
|
|
|
static int __cpuinit 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)) {
|
|
for_each_mem_cgroup(iter)
|
|
synchronize_mem_cgroup_on_move(iter, cpu);
|
|
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. */
|
|
CHARGE_OOM_DIE, /* the current is killed because of OOM */
|
|
};
|
|
|
|
static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
|
|
unsigned int nr_pages, bool oom_check)
|
|
{
|
|
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);
|
|
/*
|
|
* nr_pages can be either a huge page (HPAGE_PMD_NR), a batch
|
|
* of regular pages (CHARGE_BATCH), or a single regular page (1).
|
|
*
|
|
* Never reclaim on behalf of optional batching, retry with a
|
|
* single page instead.
|
|
*/
|
|
if (nr_pages == CHARGE_BATCH)
|
|
return CHARGE_RETRY;
|
|
|
|
if (!(gfp_mask & __GFP_WAIT))
|
|
return CHARGE_WOULDBLOCK;
|
|
|
|
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 && 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 we don't need to call oom-killer at el, return immediately */
|
|
if (!oom_check)
|
|
return CHARGE_NOMEM;
|
|
/* check OOM */
|
|
if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask))
|
|
return CHARGE_OOM_DIE;
|
|
|
|
return CHARGE_RETRY;
|
|
}
|
|
|
|
/*
|
|
* __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;
|
|
|
|
/*
|
|
* 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 init_mm (happens for pagecache usage).
|
|
*/
|
|
if (!*ptr && !mm)
|
|
*ptr = root_mem_cgroup;
|
|
again:
|
|
if (*ptr) { /* css should be a valid one */
|
|
memcg = *ptr;
|
|
VM_BUG_ON(css_is_removed(&memcg->css));
|
|
if (mem_cgroup_is_root(memcg))
|
|
goto done;
|
|
if (nr_pages == 1 && consume_stock(memcg))
|
|
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 (nr_pages == 1 && consume_stock(memcg)) {
|
|
/*
|
|
* 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 oom_check;
|
|
|
|
/* If killed, bypass charge */
|
|
if (fatal_signal_pending(current)) {
|
|
css_put(&memcg->css);
|
|
goto bypass;
|
|
}
|
|
|
|
oom_check = false;
|
|
if (oom && !nr_oom_retries) {
|
|
oom_check = true;
|
|
nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
|
|
}
|
|
|
|
ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, oom_check);
|
|
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) {
|
|
css_put(&memcg->css);
|
|
goto nomem;
|
|
}
|
|
/* If oom, we never return -ENOMEM */
|
|
nr_oom_retries--;
|
|
break;
|
|
case CHARGE_OOM_DIE: /* Killed by OOM Killer */
|
|
css_put(&memcg->css);
|
|
goto bypass;
|
|
}
|
|
} while (ret != CHARGE_OK);
|
|
|
|
if (batch > nr_pages)
|
|
refill_stock(memcg, batch - nr_pages);
|
|
css_put(&memcg->css);
|
|
done:
|
|
*ptr = memcg;
|
|
return 0;
|
|
nomem:
|
|
*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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* A helper function to get mem_cgroup from ID. must be called under
|
|
* rcu_read_lock(). The caller must check css_is_removed() or some if
|
|
* it's concern. (dropping refcnt from swap can be called against removed
|
|
* memcg.)
|
|
*/
|
|
static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
|
|
{
|
|
struct cgroup_subsys_state *css;
|
|
|
|
/* ID 0 is unused ID */
|
|
if (!id)
|
|
return NULL;
|
|
css = css_lookup(&mem_cgroup_subsys, id);
|
|
if (!css)
|
|
return NULL;
|
|
return container_of(css, struct mem_cgroup, css);
|
|
}
|
|
|
|
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(!PageLocked(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,
|
|
struct page_cgroup *pc,
|
|
enum charge_type ctype)
|
|
{
|
|
lock_page_cgroup(pc);
|
|
if (unlikely(PageCgroupUsed(pc))) {
|
|
unlock_page_cgroup(pc);
|
|
__mem_cgroup_cancel_charge(memcg, nr_pages);
|
|
return;
|
|
}
|
|
/*
|
|
* we don't need page_cgroup_lock about tail pages, becase they are not
|
|
* accessed by any other context at this point.
|
|
*/
|
|
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();
|
|
switch (ctype) {
|
|
case MEM_CGROUP_CHARGE_TYPE_CACHE:
|
|
case MEM_CGROUP_CHARGE_TYPE_SHMEM:
|
|
SetPageCgroupCache(pc);
|
|
SetPageCgroupUsed(pc);
|
|
break;
|
|
case MEM_CGROUP_CHARGE_TYPE_MAPPED:
|
|
ClearPageCgroupCache(pc);
|
|
SetPageCgroupUsed(pc);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
mem_cgroup_charge_statistics(memcg, PageCgroupCache(pc), nr_pages);
|
|
unlock_page_cgroup(pc);
|
|
WARN_ON_ONCE(PageLRU(page));
|
|
/*
|
|
* "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);
|
|
}
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
|
|
#define PCGF_NOCOPY_AT_SPLIT ((1 << PCG_LOCK) | (1 << PCG_MOVE_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;
|
|
int i;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
for (i = 1; i < HPAGE_PMD_NR; i++) {
|
|
pc = head_pc + i;
|
|
pc->mem_cgroup = head_pc->mem_cgroup;
|
|
smp_wmb();/* see __commit_charge() */
|
|
pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT;
|
|
}
|
|
}
|
|
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
|
|
|
|
/**
|
|
* 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.
|
|
* @uncharge: whether we should call uncharge and css_put against @from.
|
|
*
|
|
* 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" nor css_get to new cgroup. It should be
|
|
* done by a caller(__mem_cgroup_try_charge would be useful). If @uncharge is
|
|
* true, this function does "uncharge" from old cgroup, but it doesn't if
|
|
* @uncharge is false, so a caller should do "uncharge".
|
|
*/
|
|
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,
|
|
bool uncharge)
|
|
{
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
VM_BUG_ON(from == to);
|
|
VM_BUG_ON(PageLRU(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_page_cgroup(pc, &flags);
|
|
|
|
if (PageCgroupFileMapped(pc)) {
|
|
/* Update mapped_file data for mem_cgroup */
|
|
preempt_disable();
|
|
__this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
|
|
__this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
|
|
preempt_enable();
|
|
}
|
|
mem_cgroup_charge_statistics(from, PageCgroupCache(pc), -nr_pages);
|
|
if (uncharge)
|
|
/* This is not "cancel", but cancel_charge does all we need. */
|
|
__mem_cgroup_cancel_charge(from, nr_pages);
|
|
|
|
/* caller should have done css_get */
|
|
pc->mem_cgroup = to;
|
|
mem_cgroup_charge_statistics(to, PageCgroupCache(pc), nr_pages);
|
|
/*
|
|
* We charges against "to" which may not have any tasks. Then, "to"
|
|
* can be under rmdir(). But in current implementation, caller of
|
|
* this function is just force_empty() and move charge, so it's
|
|
* guaranteed that "to" is never removed. So, we don't check rmdir
|
|
* status here.
|
|
*/
|
|
move_unlock_page_cgroup(pc, &flags);
|
|
ret = 0;
|
|
unlock:
|
|
unlock_page_cgroup(pc);
|
|
/*
|
|
* check events
|
|
*/
|
|
memcg_check_events(to, page);
|
|
memcg_check_events(from, page);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* move charges to its parent.
|
|
*/
|
|
|
|
static int mem_cgroup_move_parent(struct page *page,
|
|
struct page_cgroup *pc,
|
|
struct mem_cgroup *child,
|
|
gfp_t gfp_mask)
|
|
{
|
|
struct cgroup *cg = child->css.cgroup;
|
|
struct cgroup *pcg = cg->parent;
|
|
struct mem_cgroup *parent;
|
|
unsigned int nr_pages;
|
|
unsigned long uninitialized_var(flags);
|
|
int ret;
|
|
|
|
/* Is ROOT ? */
|
|
if (!pcg)
|
|
return -EINVAL;
|
|
|
|
ret = -EBUSY;
|
|
if (!get_page_unless_zero(page))
|
|
goto out;
|
|
if (isolate_lru_page(page))
|
|
goto put;
|
|
|
|
nr_pages = hpage_nr_pages(page);
|
|
|
|
parent = mem_cgroup_from_cont(pcg);
|
|
ret = __mem_cgroup_try_charge(NULL, gfp_mask, nr_pages, &parent, false);
|
|
if (ret)
|
|
goto put_back;
|
|
|
|
if (nr_pages > 1)
|
|
flags = compound_lock_irqsave(page);
|
|
|
|
ret = mem_cgroup_move_account(page, nr_pages, pc, child, parent, true);
|
|
if (ret)
|
|
__mem_cgroup_cancel_charge(parent, nr_pages);
|
|
|
|
if (nr_pages > 1)
|
|
compound_unlock_irqrestore(page, flags);
|
|
put_back:
|
|
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;
|
|
struct page_cgroup *pc;
|
|
bool oom = true;
|
|
int ret;
|
|
|
|
if (PageTransHuge(page)) {
|
|
nr_pages <<= compound_order(page);
|
|
VM_BUG_ON(!PageTransHuge(page));
|
|
/*
|
|
* Never OOM-kill a process for a huge page. The
|
|
* fault handler will fall back to regular pages.
|
|
*/
|
|
oom = false;
|
|
}
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
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, pc, ctype);
|
|
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_mapped(page));
|
|
VM_BUG_ON(page->mapping && !PageAnon(page));
|
|
VM_BUG_ON(!mm);
|
|
return mem_cgroup_charge_common(page, mm, gfp_mask,
|
|
MEM_CGROUP_CHARGE_TYPE_MAPPED);
|
|
}
|
|
|
|
static void
|
|
__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
|
|
enum charge_type ctype);
|
|
|
|
static void
|
|
__mem_cgroup_commit_charge_lrucare(struct page *page, struct mem_cgroup *memcg,
|
|
enum charge_type ctype)
|
|
{
|
|
struct page_cgroup *pc = lookup_page_cgroup(page);
|
|
struct zone *zone = page_zone(page);
|
|
unsigned long flags;
|
|
bool removed = false;
|
|
|
|
/*
|
|
* In some case, SwapCache, FUSE(splice_buf->radixtree), the page
|
|
* is already on LRU. It means the page may on some other page_cgroup's
|
|
* LRU. Take care of it.
|
|
*/
|
|
spin_lock_irqsave(&zone->lru_lock, flags);
|
|
if (PageLRU(page)) {
|
|
del_page_from_lru_list(zone, page, page_lru(page));
|
|
ClearPageLRU(page);
|
|
removed = true;
|
|
}
|
|
__mem_cgroup_commit_charge(memcg, page, 1, pc, ctype);
|
|
if (removed) {
|
|
add_page_to_lru_list(zone, page, page_lru(page));
|
|
SetPageLRU(page);
|
|
}
|
|
spin_unlock_irqrestore(&zone->lru_lock, flags);
|
|
return;
|
|
}
|
|
|
|
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 (unlikely(!mm))
|
|
mm = &init_mm;
|
|
if (!page_is_file_cache(page))
|
|
type = MEM_CGROUP_CHARGE_TYPE_SHMEM;
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* 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()"
|
|
*/
|
|
int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
|
|
struct page *page,
|
|
gfp_t mask, struct mem_cgroup **memcgp)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
int ret;
|
|
|
|
*memcgp = NULL;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return 0;
|
|
|
|
if (!do_swap_account)
|
|
goto charge_cur_mm;
|
|
/*
|
|
* A racing thread's fault, or swapoff, may have already updated
|
|
* the pte, and even removed page from swap cache: in those cases
|
|
* do_swap_page()'s pte_same() test will fail; but there's also a
|
|
* KSM case which does need to charge the page.
|
|
*/
|
|
if (!PageSwapCache(page))
|
|
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:
|
|
if (unlikely(!mm))
|
|
mm = &init_mm;
|
|
ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true);
|
|
if (ret == -EINTR)
|
|
ret = 0;
|
|
return ret;
|
|
}
|
|
|
|
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;
|
|
cgroup_exclude_rmdir(&memcg->css);
|
|
|
|
__mem_cgroup_commit_charge_lrucare(page, memcg, ctype);
|
|
/*
|
|
* 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)};
|
|
struct mem_cgroup *swap_memcg;
|
|
unsigned short id;
|
|
|
|
id = swap_cgroup_record(ent, 0);
|
|
rcu_read_lock();
|
|
swap_memcg = mem_cgroup_lookup(id);
|
|
if (swap_memcg) {
|
|
/*
|
|
* This recorded memcg can be obsolete one. So, avoid
|
|
* calling css_tryget
|
|
*/
|
|
if (!mem_cgroup_is_root(swap_memcg))
|
|
res_counter_uncharge(&swap_memcg->memsw,
|
|
PAGE_SIZE);
|
|
mem_cgroup_swap_statistics(swap_memcg, false);
|
|
mem_cgroup_put(swap_memcg);
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
/*
|
|
* At swapin, we may charge account against cgroup which has no tasks.
|
|
* So, rmdir()->pre_destroy() can be called while we do this charge.
|
|
* In that case, we need to call pre_destroy() again. check it here.
|
|
*/
|
|
cgroup_release_and_wakeup_rmdir(&memcg->css);
|
|
}
|
|
|
|
void mem_cgroup_commit_charge_swapin(struct page *page,
|
|
struct mem_cgroup *memcg)
|
|
{
|
|
__mem_cgroup_commit_charge_swapin(page, memcg,
|
|
MEM_CGROUP_CHARGE_TYPE_MAPPED);
|
|
}
|
|
|
|
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_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);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* uncharge if !page_mapped(page)
|
|
*/
|
|
static struct mem_cgroup *
|
|
__mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
unsigned int nr_pages = 1;
|
|
struct page_cgroup *pc;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return NULL;
|
|
|
|
if (PageSwapCache(page))
|
|
return NULL;
|
|
|
|
if (PageTransHuge(page)) {
|
|
nr_pages <<= compound_order(page);
|
|
VM_BUG_ON(!PageTransHuge(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;
|
|
|
|
switch (ctype) {
|
|
case MEM_CGROUP_CHARGE_TYPE_MAPPED:
|
|
case MEM_CGROUP_CHARGE_TYPE_DROP:
|
|
/* See mem_cgroup_prepare_migration() */
|
|
if (page_mapped(page) || 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, PageCgroupCache(pc), -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.
|
|
*/
|
|
memcg_check_events(memcg, page);
|
|
if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) {
|
|
mem_cgroup_swap_statistics(memcg, true);
|
|
mem_cgroup_get(memcg);
|
|
}
|
|
if (!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->mapping && !PageAnon(page));
|
|
__mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
|
|
}
|
|
|
|
void mem_cgroup_uncharge_cache_page(struct page *page)
|
|
{
|
|
VM_BUG_ON(page_mapped(page));
|
|
VM_BUG_ON(page->mapping);
|
|
__mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
/*
|
|
* A function for resetting pc->mem_cgroup for newly allocated pages.
|
|
* This function should be called if the newpage will be added to LRU
|
|
* before start accounting.
|
|
*/
|
|
void mem_cgroup_reset_owner(struct page *newpage)
|
|
{
|
|
struct page_cgroup *pc;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
pc = lookup_page_cgroup(newpage);
|
|
VM_BUG_ON(PageCgroupUsed(pc));
|
|
pc->mem_cgroup = root_mem_cgroup;
|
|
}
|
|
|
|
#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);
|
|
|
|
/*
|
|
* record memcg information, if swapout && memcg != NULL,
|
|
* mem_cgroup_get() was called in uncharge().
|
|
*/
|
|
if (do_swap_account && swapout && memcg)
|
|
swap_cgroup_record(ent, css_id(&memcg->css));
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_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);
|
|
mem_cgroup_put(memcg);
|
|
}
|
|
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
|
|
* @need_fixup: whether we should fixup res_counters and refcounts.
|
|
*
|
|
* 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, bool need_fixup)
|
|
{
|
|
unsigned short old_id, new_id;
|
|
|
|
old_id = css_id(&from->css);
|
|
new_id = css_id(&to->css);
|
|
|
|
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 mem_cgroup_get(to)
|
|
* because if the process that has been moved to @to does
|
|
* swap-in, the refcount of @to might be decreased to 0.
|
|
*/
|
|
mem_cgroup_get(to);
|
|
if (need_fixup) {
|
|
if (!mem_cgroup_is_root(from))
|
|
res_counter_uncharge(&from->memsw, PAGE_SIZE);
|
|
mem_cgroup_put(from);
|
|
/*
|
|
* we charged both to->res and to->memsw, so we should
|
|
* uncharge to->res.
|
|
*/
|
|
if (!mem_cgroup_is_root(to))
|
|
res_counter_uncharge(&to->res, PAGE_SIZE);
|
|
}
|
|
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, bool need_fixup)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Before starting migration, account PAGE_SIZE to mem_cgroup that the old
|
|
* page belongs to.
|
|
*/
|
|
int mem_cgroup_prepare_migration(struct page *page,
|
|
struct page *newpage, struct mem_cgroup **memcgp, gfp_t gfp_mask)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
struct page_cgroup *pc;
|
|
enum charge_type ctype;
|
|
int ret = 0;
|
|
|
|
*memcgp = NULL;
|
|
|
|
VM_BUG_ON(PageTransHuge(page));
|
|
if (mem_cgroup_disabled())
|
|
return 0;
|
|
|
|
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 0;
|
|
|
|
*memcgp = memcg;
|
|
ret = __mem_cgroup_try_charge(NULL, gfp_mask, 1, memcgp, false);
|
|
css_put(&memcg->css);/* drop extra refcnt */
|
|
if (ret) {
|
|
if (PageAnon(page)) {
|
|
lock_page_cgroup(pc);
|
|
ClearPageCgroupMigration(pc);
|
|
unlock_page_cgroup(pc);
|
|
/*
|
|
* The old page may be fully unmapped while we kept it.
|
|
*/
|
|
mem_cgroup_uncharge_page(page);
|
|
}
|
|
/* we'll need to revisit this error code (we have -EINTR) */
|
|
return -ENOMEM;
|
|
}
|
|
/*
|
|
* 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().
|
|
*/
|
|
pc = lookup_page_cgroup(newpage);
|
|
if (PageAnon(page))
|
|
ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
|
|
else if (page_is_file_cache(page))
|
|
ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
|
|
else
|
|
ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
|
|
__mem_cgroup_commit_charge(memcg, page, 1, pc, ctype);
|
|
return ret;
|
|
}
|
|
|
|
/* 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;
|
|
|
|
if (!memcg)
|
|
return;
|
|
/* blocks rmdir() */
|
|
cgroup_exclude_rmdir(&memcg->css);
|
|
if (!migration_ok) {
|
|
used = oldpage;
|
|
unused = newpage;
|
|
} else {
|
|
used = newpage;
|
|
unused = oldpage;
|
|
}
|
|
/*
|
|
* 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);
|
|
|
|
__mem_cgroup_uncharge_common(unused, MEM_CGROUP_CHARGE_TYPE_FORCE);
|
|
|
|
/*
|
|
* 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 (PageAnon(used))
|
|
mem_cgroup_uncharge_page(used);
|
|
/*
|
|
* At migration, we may charge account against cgroup which has no
|
|
* tasks.
|
|
* So, rmdir()->pre_destroy() can be called while we do this charge.
|
|
* In that case, we need to call pre_destroy() again. check it here.
|
|
*/
|
|
cgroup_release_and_wakeup_rmdir(&memcg->css);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
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);
|
|
memcg = pc->mem_cgroup;
|
|
mem_cgroup_charge_statistics(memcg, PageCgroupCache(pc), -1);
|
|
ClearPageCgroupUsed(pc);
|
|
unlock_page_cgroup(pc);
|
|
|
|
if (PageSwapBacked(oldpage))
|
|
type = MEM_CGROUP_CHARGE_TYPE_SHMEM;
|
|
|
|
/*
|
|
* 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_lrucare(newpage, memcg, type);
|
|
}
|
|
|
|
#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) {
|
|
printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
|
|
pc, pc->flags, pc->mem_cgroup);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
static DEFINE_MUTEX(set_limit_mutex);
|
|
|
|
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->mem, 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->mem->css);
|
|
else /* next_mz == NULL or other memcg */
|
|
break;
|
|
} while (1);
|
|
}
|
|
__mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
|
|
excess = res_counter_soft_limit_excess(&mz->mem->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->mem, mz, mctz, excess);
|
|
spin_unlock(&mctz->lock);
|
|
css_put(&mz->mem->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->mem->css);
|
|
return nr_reclaimed;
|
|
}
|
|
|
|
/*
|
|
* This routine traverse page_cgroup in given list and drop them all.
|
|
* *And* this routine doesn't reclaim page itself, just removes page_cgroup.
|
|
*/
|
|
static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
|
|
int node, int zid, enum lru_list lru)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
unsigned long flags, loop;
|
|
struct list_head *list;
|
|
struct page *busy;
|
|
struct zone *zone;
|
|
int ret = 0;
|
|
|
|
zone = &NODE_DATA(node)->node_zones[zid];
|
|
mz = mem_cgroup_zoneinfo(memcg, node, zid);
|
|
list = &mz->lruvec.lists[lru];
|
|
|
|
loop = MEM_CGROUP_ZSTAT(mz, lru);
|
|
/* give some margin against EBUSY etc...*/
|
|
loop += 256;
|
|
busy = NULL;
|
|
while (loop--) {
|
|
struct page_cgroup *pc;
|
|
struct page *page;
|
|
|
|
ret = 0;
|
|
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);
|
|
|
|
ret = mem_cgroup_move_parent(page, pc, memcg, GFP_KERNEL);
|
|
if (ret == -ENOMEM || ret == -EINTR)
|
|
break;
|
|
|
|
if (ret == -EBUSY || ret == -EINVAL) {
|
|
/* found lock contention or "pc" is obsolete. */
|
|
busy = page;
|
|
cond_resched();
|
|
} else
|
|
busy = NULL;
|
|
}
|
|
|
|
if (!ret && !list_empty(list))
|
|
return -EBUSY;
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* make mem_cgroup's charge to be 0 if there is no task.
|
|
* This enables deleting this mem_cgroup.
|
|
*/
|
|
static int mem_cgroup_force_empty(struct mem_cgroup *memcg, bool free_all)
|
|
{
|
|
int ret;
|
|
int node, zid, shrink;
|
|
int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
|
|
struct cgroup *cgrp = memcg->css.cgroup;
|
|
|
|
css_get(&memcg->css);
|
|
|
|
shrink = 0;
|
|
/* should free all ? */
|
|
if (free_all)
|
|
goto try_to_free;
|
|
move_account:
|
|
do {
|
|
ret = -EBUSY;
|
|
if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
|
|
goto out;
|
|
ret = -EINTR;
|
|
if (signal_pending(current))
|
|
goto out;
|
|
/* This is for making all *used* pages to be on LRU. */
|
|
lru_add_drain_all();
|
|
drain_all_stock_sync(memcg);
|
|
ret = 0;
|
|
mem_cgroup_start_move(memcg);
|
|
for_each_node_state(node, N_HIGH_MEMORY) {
|
|
for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
|
|
enum lru_list l;
|
|
for_each_lru(l) {
|
|
ret = mem_cgroup_force_empty_list(memcg,
|
|
node, zid, l);
|
|
if (ret)
|
|
break;
|
|
}
|
|
}
|
|
if (ret)
|
|
break;
|
|
}
|
|
mem_cgroup_end_move(memcg);
|
|
memcg_oom_recover(memcg);
|
|
/* it seems parent cgroup doesn't have enough mem */
|
|
if (ret == -ENOMEM)
|
|
goto try_to_free;
|
|
cond_resched();
|
|
/* "ret" should also be checked to ensure all lists are empty. */
|
|
} while (memcg->res.usage > 0 || ret);
|
|
out:
|
|
css_put(&memcg->css);
|
|
return ret;
|
|
|
|
try_to_free:
|
|
/* returns EBUSY if there is a task or if we come here twice. */
|
|
if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
/* we call try-to-free pages for make this cgroup empty */
|
|
lru_add_drain_all();
|
|
/* try to free all pages in this cgroup */
|
|
shrink = 1;
|
|
while (nr_retries && memcg->res.usage > 0) {
|
|
int progress;
|
|
|
|
if (signal_pending(current)) {
|
|
ret = -EINTR;
|
|
goto out;
|
|
}
|
|
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();
|
|
/* try move_account...there may be some *locked* pages. */
|
|
goto move_account;
|
|
}
|
|
|
|
int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
|
|
{
|
|
return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
|
|
}
|
|
|
|
|
|
static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft)
|
|
{
|
|
return mem_cgroup_from_cont(cont)->use_hierarchy;
|
|
}
|
|
|
|
static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft,
|
|
u64 val)
|
|
{
|
|
int retval = 0;
|
|
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
|
|
struct cgroup *parent = cont->parent;
|
|
struct mem_cgroup *parent_memcg = NULL;
|
|
|
|
if (parent)
|
|
parent_memcg = mem_cgroup_from_cont(parent);
|
|
|
|
cgroup_lock();
|
|
/*
|
|
* 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(&cont->children))
|
|
memcg->use_hierarchy = val;
|
|
else
|
|
retval = -EBUSY;
|
|
} else
|
|
retval = -EINVAL;
|
|
cgroup_unlock();
|
|
|
|
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);
|
|
}
|
|
|
|
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_SWAPOUT);
|
|
|
|
return val << PAGE_SHIFT;
|
|
}
|
|
|
|
static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
|
|
u64 val;
|
|
int type, name;
|
|
|
|
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;
|
|
default:
|
|
BUG();
|
|
break;
|
|
}
|
|
return val;
|
|
}
|
|
/*
|
|
* The user of this function is...
|
|
* RES_LIMIT.
|
|
*/
|
|
static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
|
|
const char *buffer)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
|
|
int type, 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
|
|
ret = mem_cgroup_resize_memsw_limit(memcg, val);
|
|
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)
|
|
{
|
|
struct cgroup *cgroup;
|
|
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);
|
|
cgroup = memcg->css.cgroup;
|
|
if (!memcg->use_hierarchy)
|
|
goto out;
|
|
|
|
while (cgroup->parent) {
|
|
cgroup = cgroup->parent;
|
|
memcg = mem_cgroup_from_cont(cgroup);
|
|
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;
|
|
return;
|
|
}
|
|
|
|
static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
int type, name;
|
|
|
|
memcg = mem_cgroup_from_cont(cont);
|
|
type = MEMFILE_TYPE(event);
|
|
name = MEMFILE_ATTR(event);
|
|
switch (name) {
|
|
case RES_MAX_USAGE:
|
|
if (type == _MEM)
|
|
res_counter_reset_max(&memcg->res);
|
|
else
|
|
res_counter_reset_max(&memcg->memsw);
|
|
break;
|
|
case RES_FAILCNT:
|
|
if (type == _MEM)
|
|
res_counter_reset_failcnt(&memcg->res);
|
|
else
|
|
res_counter_reset_failcnt(&memcg->memsw);
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp,
|
|
struct cftype *cft)
|
|
{
|
|
return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate;
|
|
}
|
|
|
|
#ifdef CONFIG_MMU
|
|
static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
|
|
|
|
if (val >= (1 << NR_MOVE_TYPE))
|
|
return -EINVAL;
|
|
/*
|
|
* We check this value several times in both in can_attach() and
|
|
* attach(), so we need cgroup lock to prevent this value from being
|
|
* inconsistent.
|
|
*/
|
|
cgroup_lock();
|
|
memcg->move_charge_at_immigrate = val;
|
|
cgroup_unlock();
|
|
|
|
return 0;
|
|
}
|
|
#else
|
|
static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
#endif
|
|
|
|
|
|
/* For read statistics */
|
|
enum {
|
|
MCS_CACHE,
|
|
MCS_RSS,
|
|
MCS_FILE_MAPPED,
|
|
MCS_PGPGIN,
|
|
MCS_PGPGOUT,
|
|
MCS_SWAP,
|
|
MCS_PGFAULT,
|
|
MCS_PGMAJFAULT,
|
|
MCS_INACTIVE_ANON,
|
|
MCS_ACTIVE_ANON,
|
|
MCS_INACTIVE_FILE,
|
|
MCS_ACTIVE_FILE,
|
|
MCS_UNEVICTABLE,
|
|
NR_MCS_STAT,
|
|
};
|
|
|
|
struct mcs_total_stat {
|
|
s64 stat[NR_MCS_STAT];
|
|
};
|
|
|
|
struct {
|
|
char *local_name;
|
|
char *total_name;
|
|
} memcg_stat_strings[NR_MCS_STAT] = {
|
|
{"cache", "total_cache"},
|
|
{"rss", "total_rss"},
|
|
{"mapped_file", "total_mapped_file"},
|
|
{"pgpgin", "total_pgpgin"},
|
|
{"pgpgout", "total_pgpgout"},
|
|
{"swap", "total_swap"},
|
|
{"pgfault", "total_pgfault"},
|
|
{"pgmajfault", "total_pgmajfault"},
|
|
{"inactive_anon", "total_inactive_anon"},
|
|
{"active_anon", "total_active_anon"},
|
|
{"inactive_file", "total_inactive_file"},
|
|
{"active_file", "total_active_file"},
|
|
{"unevictable", "total_unevictable"}
|
|
};
|
|
|
|
|
|
static void
|
|
mem_cgroup_get_local_stat(struct mem_cgroup *memcg, struct mcs_total_stat *s)
|
|
{
|
|
s64 val;
|
|
|
|
/* per cpu stat */
|
|
val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_CACHE);
|
|
s->stat[MCS_CACHE] += val * PAGE_SIZE;
|
|
val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_RSS);
|
|
s->stat[MCS_RSS] += val * PAGE_SIZE;
|
|
val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_FILE_MAPPED);
|
|
s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE;
|
|
val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGPGIN);
|
|
s->stat[MCS_PGPGIN] += val;
|
|
val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGPGOUT);
|
|
s->stat[MCS_PGPGOUT] += val;
|
|
if (do_swap_account) {
|
|
val = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_SWAPOUT);
|
|
s->stat[MCS_SWAP] += val * PAGE_SIZE;
|
|
}
|
|
val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGFAULT);
|
|
s->stat[MCS_PGFAULT] += val;
|
|
val = mem_cgroup_read_events(memcg, MEM_CGROUP_EVENTS_PGMAJFAULT);
|
|
s->stat[MCS_PGMAJFAULT] += val;
|
|
|
|
/* per zone stat */
|
|
val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_INACTIVE_ANON));
|
|
s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE;
|
|
val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_ACTIVE_ANON));
|
|
s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE;
|
|
val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_INACTIVE_FILE));
|
|
s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE;
|
|
val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_ACTIVE_FILE));
|
|
s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE;
|
|
val = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE));
|
|
s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE;
|
|
}
|
|
|
|
static void
|
|
mem_cgroup_get_total_stat(struct mem_cgroup *memcg, struct mcs_total_stat *s)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
mem_cgroup_get_local_stat(iter, s);
|
|
}
|
|
|
|
#ifdef CONFIG_NUMA
|
|
static int mem_control_numa_stat_show(struct seq_file *m, void *arg)
|
|
{
|
|
int nid;
|
|
unsigned long total_nr, file_nr, anon_nr, unevictable_nr;
|
|
unsigned long node_nr;
|
|
struct cgroup *cont = m->private;
|
|
struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
|
|
|
|
total_nr = mem_cgroup_nr_lru_pages(mem_cont, LRU_ALL);
|
|
seq_printf(m, "total=%lu", total_nr);
|
|
for_each_node_state(nid, N_HIGH_MEMORY) {
|
|
node_nr = mem_cgroup_node_nr_lru_pages(mem_cont, nid, LRU_ALL);
|
|
seq_printf(m, " N%d=%lu", nid, node_nr);
|
|
}
|
|
seq_putc(m, '\n');
|
|
|
|
file_nr = mem_cgroup_nr_lru_pages(mem_cont, LRU_ALL_FILE);
|
|
seq_printf(m, "file=%lu", file_nr);
|
|
for_each_node_state(nid, N_HIGH_MEMORY) {
|
|
node_nr = mem_cgroup_node_nr_lru_pages(mem_cont, nid,
|
|
LRU_ALL_FILE);
|
|
seq_printf(m, " N%d=%lu", nid, node_nr);
|
|
}
|
|
seq_putc(m, '\n');
|
|
|
|
anon_nr = mem_cgroup_nr_lru_pages(mem_cont, LRU_ALL_ANON);
|
|
seq_printf(m, "anon=%lu", anon_nr);
|
|
for_each_node_state(nid, N_HIGH_MEMORY) {
|
|
node_nr = mem_cgroup_node_nr_lru_pages(mem_cont, nid,
|
|
LRU_ALL_ANON);
|
|
seq_printf(m, " N%d=%lu", nid, node_nr);
|
|
}
|
|
seq_putc(m, '\n');
|
|
|
|
unevictable_nr = mem_cgroup_nr_lru_pages(mem_cont, BIT(LRU_UNEVICTABLE));
|
|
seq_printf(m, "unevictable=%lu", unevictable_nr);
|
|
for_each_node_state(nid, N_HIGH_MEMORY) {
|
|
node_nr = mem_cgroup_node_nr_lru_pages(mem_cont, nid,
|
|
BIT(LRU_UNEVICTABLE));
|
|
seq_printf(m, " N%d=%lu", nid, node_nr);
|
|
}
|
|
seq_putc(m, '\n');
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_NUMA */
|
|
|
|
static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
|
|
struct cgroup_map_cb *cb)
|
|
{
|
|
struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
|
|
struct mcs_total_stat mystat;
|
|
int i;
|
|
|
|
memset(&mystat, 0, sizeof(mystat));
|
|
mem_cgroup_get_local_stat(mem_cont, &mystat);
|
|
|
|
|
|
for (i = 0; i < NR_MCS_STAT; i++) {
|
|
if (i == MCS_SWAP && !do_swap_account)
|
|
continue;
|
|
cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]);
|
|
}
|
|
|
|
/* Hierarchical information */
|
|
{
|
|
unsigned long long limit, memsw_limit;
|
|
memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit);
|
|
cb->fill(cb, "hierarchical_memory_limit", limit);
|
|
if (do_swap_account)
|
|
cb->fill(cb, "hierarchical_memsw_limit", memsw_limit);
|
|
}
|
|
|
|
memset(&mystat, 0, sizeof(mystat));
|
|
mem_cgroup_get_total_stat(mem_cont, &mystat);
|
|
for (i = 0; i < NR_MCS_STAT; i++) {
|
|
if (i == MCS_SWAP && !do_swap_account)
|
|
continue;
|
|
cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]);
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_VM
|
|
{
|
|
int nid, zid;
|
|
struct mem_cgroup_per_zone *mz;
|
|
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(mem_cont, nid, zid);
|
|
|
|
recent_rotated[0] +=
|
|
mz->reclaim_stat.recent_rotated[0];
|
|
recent_rotated[1] +=
|
|
mz->reclaim_stat.recent_rotated[1];
|
|
recent_scanned[0] +=
|
|
mz->reclaim_stat.recent_scanned[0];
|
|
recent_scanned[1] +=
|
|
mz->reclaim_stat.recent_scanned[1];
|
|
}
|
|
cb->fill(cb, "recent_rotated_anon", recent_rotated[0]);
|
|
cb->fill(cb, "recent_rotated_file", recent_rotated[1]);
|
|
cb->fill(cb, "recent_scanned_anon", recent_scanned[0]);
|
|
cb->fill(cb, "recent_scanned_file", recent_scanned[1]);
|
|
}
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
|
|
|
|
return mem_cgroup_swappiness(memcg);
|
|
}
|
|
|
|
static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
|
|
u64 val)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
|
|
struct mem_cgroup *parent;
|
|
|
|
if (val > 100)
|
|
return -EINVAL;
|
|
|
|
if (cgrp->parent == NULL)
|
|
return -EINVAL;
|
|
|
|
parent = mem_cgroup_from_cont(cgrp->parent);
|
|
|
|
cgroup_lock();
|
|
|
|
/* If under hierarchy, only empty-root can set this value */
|
|
if ((parent->use_hierarchy) ||
|
|
(memcg->use_hierarchy && !list_empty(&cgrp->children))) {
|
|
cgroup_unlock();
|
|
return -EINVAL;
|
|
}
|
|
|
|
memcg->swappiness = val;
|
|
|
|
cgroup_unlock();
|
|
|
|
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 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;
|
|
|
|
return _a->threshold - _b->threshold;
|
|
}
|
|
|
|
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 cgroup *cgrp,
|
|
struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
|
|
struct mem_cgroup_thresholds *thresholds;
|
|
struct mem_cgroup_threshold_ary *new;
|
|
int type = MEMFILE_TYPE(cft->private);
|
|
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;
|
|
}
|
|
}
|
|
|
|
/* 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 void mem_cgroup_usage_unregister_event(struct cgroup *cgrp,
|
|
struct cftype *cft, struct eventfd_ctx *eventfd)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
|
|
struct mem_cgroup_thresholds *thresholds;
|
|
struct mem_cgroup_threshold_ary *new;
|
|
int type = MEMFILE_TYPE(cft->private);
|
|
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();
|
|
|
|
/*
|
|
* Something went wrong if we trying to unregister a threshold
|
|
* if we don't have thresholds
|
|
*/
|
|
BUG_ON(!thresholds);
|
|
|
|
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;
|
|
rcu_assign_pointer(thresholds->primary, new);
|
|
|
|
/* To be sure that nobody uses thresholds */
|
|
synchronize_rcu();
|
|
|
|
mutex_unlock(&memcg->thresholds_lock);
|
|
}
|
|
|
|
static int mem_cgroup_oom_register_event(struct cgroup *cgrp,
|
|
struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
|
|
struct mem_cgroup_eventfd_list *event;
|
|
int type = MEMFILE_TYPE(cft->private);
|
|
|
|
BUG_ON(type != _OOM_TYPE);
|
|
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 cgroup *cgrp,
|
|
struct cftype *cft, struct eventfd_ctx *eventfd)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
|
|
struct mem_cgroup_eventfd_list *ev, *tmp;
|
|
int type = MEMFILE_TYPE(cft->private);
|
|
|
|
BUG_ON(type != _OOM_TYPE);
|
|
|
|
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 cgroup *cgrp,
|
|
struct cftype *cft, struct cgroup_map_cb *cb)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
|
|
|
|
cb->fill(cb, "oom_kill_disable", memcg->oom_kill_disable);
|
|
|
|
if (atomic_read(&memcg->under_oom))
|
|
cb->fill(cb, "under_oom", 1);
|
|
else
|
|
cb->fill(cb, "under_oom", 0);
|
|
return 0;
|
|
}
|
|
|
|
static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
|
|
struct mem_cgroup *parent;
|
|
|
|
/* cannot set to root cgroup and only 0 and 1 are allowed */
|
|
if (!cgrp->parent || !((val == 0) || (val == 1)))
|
|
return -EINVAL;
|
|
|
|
parent = mem_cgroup_from_cont(cgrp->parent);
|
|
|
|
cgroup_lock();
|
|
/* oom-kill-disable is a flag for subhierarchy. */
|
|
if ((parent->use_hierarchy) ||
|
|
(memcg->use_hierarchy && !list_empty(&cgrp->children))) {
|
|
cgroup_unlock();
|
|
return -EINVAL;
|
|
}
|
|
memcg->oom_kill_disable = val;
|
|
if (!val)
|
|
memcg_oom_recover(memcg);
|
|
cgroup_unlock();
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_NUMA
|
|
static const struct file_operations mem_control_numa_stat_file_operations = {
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = single_release,
|
|
};
|
|
|
|
static int mem_control_numa_stat_open(struct inode *unused, struct file *file)
|
|
{
|
|
struct cgroup *cont = file->f_dentry->d_parent->d_fsdata;
|
|
|
|
file->f_op = &mem_control_numa_stat_file_operations;
|
|
return single_open(file, mem_control_numa_stat_show, cont);
|
|
}
|
|
#endif /* CONFIG_NUMA */
|
|
|
|
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
|
|
static int register_kmem_files(struct cgroup *cont, struct cgroup_subsys *ss)
|
|
{
|
|
/*
|
|
* Part of this would be better living in a separate allocation
|
|
* function, leaving us with just the cgroup tree population work.
|
|
* We, however, depend on state such as network's proto_list that
|
|
* is only initialized after cgroup creation. I found the less
|
|
* cumbersome way to deal with it to defer it all to populate time
|
|
*/
|
|
return mem_cgroup_sockets_init(cont, ss);
|
|
};
|
|
|
|
static void kmem_cgroup_destroy(struct cgroup_subsys *ss,
|
|
struct cgroup *cont)
|
|
{
|
|
mem_cgroup_sockets_destroy(cont, ss);
|
|
}
|
|
#else
|
|
static int register_kmem_files(struct cgroup *cont, struct cgroup_subsys *ss)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void kmem_cgroup_destroy(struct cgroup_subsys *ss,
|
|
struct cgroup *cont)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
static struct cftype mem_cgroup_files[] = {
|
|
{
|
|
.name = "usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
|
|
.read_u64 = mem_cgroup_read,
|
|
.register_event = mem_cgroup_usage_register_event,
|
|
.unregister_event = mem_cgroup_usage_unregister_event,
|
|
},
|
|
{
|
|
.name = "max_usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
|
|
.trigger = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
|
|
.write_string = mem_cgroup_write,
|
|
.read_u64 = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "soft_limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
|
|
.write_string = mem_cgroup_write,
|
|
.read_u64 = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "failcnt",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
|
|
.trigger = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "stat",
|
|
.read_map = mem_control_stat_show,
|
|
},
|
|
{
|
|
.name = "force_empty",
|
|
.trigger = mem_cgroup_force_empty_write,
|
|
},
|
|
{
|
|
.name = "use_hierarchy",
|
|
.write_u64 = mem_cgroup_hierarchy_write,
|
|
.read_u64 = mem_cgroup_hierarchy_read,
|
|
},
|
|
{
|
|
.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",
|
|
.read_map = mem_cgroup_oom_control_read,
|
|
.write_u64 = mem_cgroup_oom_control_write,
|
|
.register_event = mem_cgroup_oom_register_event,
|
|
.unregister_event = mem_cgroup_oom_unregister_event,
|
|
.private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
|
|
},
|
|
#ifdef CONFIG_NUMA
|
|
{
|
|
.name = "numa_stat",
|
|
.open = mem_control_numa_stat_open,
|
|
.mode = S_IRUGO,
|
|
},
|
|
#endif
|
|
};
|
|
|
|
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
|
|
static struct cftype memsw_cgroup_files[] = {
|
|
{
|
|
.name = "memsw.usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
|
|
.read_u64 = mem_cgroup_read,
|
|
.register_event = mem_cgroup_usage_register_event,
|
|
.unregister_event = mem_cgroup_usage_unregister_event,
|
|
},
|
|
{
|
|
.name = "memsw.max_usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
|
|
.trigger = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "memsw.limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
|
|
.write_string = mem_cgroup_write,
|
|
.read_u64 = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "memsw.failcnt",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
|
|
.trigger = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read,
|
|
},
|
|
};
|
|
|
|
static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
|
|
{
|
|
if (!do_swap_account)
|
|
return 0;
|
|
return cgroup_add_files(cont, ss, memsw_cgroup_files,
|
|
ARRAY_SIZE(memsw_cgroup_files));
|
|
};
|
|
#else
|
|
static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss)
|
|
{
|
|
return 0;
|
|
}
|
|
#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;
|
|
enum lru_list l;
|
|
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];
|
|
for_each_lru(l)
|
|
INIT_LIST_HEAD(&mz->lruvec.lists[l]);
|
|
mz->usage_in_excess = 0;
|
|
mz->on_tree = false;
|
|
mz->mem = memcg;
|
|
}
|
|
memcg->info.nodeinfo[node] = pn;
|
|
return 0;
|
|
}
|
|
|
|
static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
|
|
{
|
|
kfree(memcg->info.nodeinfo[node]);
|
|
}
|
|
|
|
static struct mem_cgroup *mem_cgroup_alloc(void)
|
|
{
|
|
struct mem_cgroup *mem;
|
|
int size = sizeof(struct mem_cgroup);
|
|
|
|
/* Can be very big if MAX_NUMNODES is very big */
|
|
if (size < PAGE_SIZE)
|
|
mem = kzalloc(size, GFP_KERNEL);
|
|
else
|
|
mem = vzalloc(size);
|
|
|
|
if (!mem)
|
|
return NULL;
|
|
|
|
mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
|
|
if (!mem->stat)
|
|
goto out_free;
|
|
spin_lock_init(&mem->pcp_counter_lock);
|
|
return mem;
|
|
|
|
out_free:
|
|
if (size < PAGE_SIZE)
|
|
kfree(mem);
|
|
else
|
|
vfree(mem);
|
|
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);
|
|
free_css_id(&mem_cgroup_subsys, &memcg->css);
|
|
|
|
for_each_node(node)
|
|
free_mem_cgroup_per_zone_info(memcg, node);
|
|
|
|
free_percpu(memcg->stat);
|
|
if (sizeof(struct mem_cgroup) < PAGE_SIZE)
|
|
kfree(memcg);
|
|
else
|
|
vfree(memcg);
|
|
}
|
|
|
|
static void mem_cgroup_get(struct mem_cgroup *memcg)
|
|
{
|
|
atomic_inc(&memcg->refcnt);
|
|
}
|
|
|
|
static void __mem_cgroup_put(struct mem_cgroup *memcg, int count)
|
|
{
|
|
if (atomic_sub_and_test(count, &memcg->refcnt)) {
|
|
struct mem_cgroup *parent = parent_mem_cgroup(memcg);
|
|
__mem_cgroup_free(memcg);
|
|
if (parent)
|
|
mem_cgroup_put(parent);
|
|
}
|
|
}
|
|
|
|
static void mem_cgroup_put(struct mem_cgroup *memcg)
|
|
{
|
|
__mem_cgroup_put(memcg, 1);
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
|
|
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
|
|
static void __init enable_swap_cgroup(void)
|
|
{
|
|
if (!mem_cgroup_disabled() && really_do_swap_account)
|
|
do_swap_account = 1;
|
|
}
|
|
#else
|
|
static void __init enable_swap_cgroup(void)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
static int 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);
|
|
if (!rtpn)
|
|
goto err_cleanup;
|
|
|
|
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);
|
|
}
|
|
}
|
|
return 0;
|
|
|
|
err_cleanup:
|
|
for_each_node(node) {
|
|
if (!soft_limit_tree.rb_tree_per_node[node])
|
|
break;
|
|
kfree(soft_limit_tree.rb_tree_per_node[node]);
|
|
soft_limit_tree.rb_tree_per_node[node] = NULL;
|
|
}
|
|
return 1;
|
|
|
|
}
|
|
|
|
static struct cgroup_subsys_state * __ref
|
|
mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
|
|
{
|
|
struct mem_cgroup *memcg, *parent;
|
|
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 (cont->parent == NULL) {
|
|
int cpu;
|
|
enable_swap_cgroup();
|
|
parent = NULL;
|
|
if (mem_cgroup_soft_limit_tree_init())
|
|
goto free_out;
|
|
root_mem_cgroup = memcg;
|
|
for_each_possible_cpu(cpu) {
|
|
struct memcg_stock_pcp *stock =
|
|
&per_cpu(memcg_stock, cpu);
|
|
INIT_WORK(&stock->work, drain_local_stock);
|
|
}
|
|
hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
|
|
} else {
|
|
parent = mem_cgroup_from_cont(cont->parent);
|
|
memcg->use_hierarchy = parent->use_hierarchy;
|
|
memcg->oom_kill_disable = parent->oom_kill_disable;
|
|
}
|
|
|
|
if (parent && parent->use_hierarchy) {
|
|
res_counter_init(&memcg->res, &parent->res);
|
|
res_counter_init(&memcg->memsw, &parent->memsw);
|
|
/*
|
|
* We increment refcnt of the parent to ensure that we can
|
|
* safely access it on res_counter_charge/uncharge.
|
|
* This refcnt will be decremented when freeing this
|
|
* mem_cgroup(see mem_cgroup_put).
|
|
*/
|
|
mem_cgroup_get(parent);
|
|
} else {
|
|
res_counter_init(&memcg->res, NULL);
|
|
res_counter_init(&memcg->memsw, NULL);
|
|
}
|
|
memcg->last_scanned_node = MAX_NUMNODES;
|
|
INIT_LIST_HEAD(&memcg->oom_notify);
|
|
|
|
if (parent)
|
|
memcg->swappiness = mem_cgroup_swappiness(parent);
|
|
atomic_set(&memcg->refcnt, 1);
|
|
memcg->move_charge_at_immigrate = 0;
|
|
mutex_init(&memcg->thresholds_lock);
|
|
return &memcg->css;
|
|
free_out:
|
|
__mem_cgroup_free(memcg);
|
|
return ERR_PTR(error);
|
|
}
|
|
|
|
static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
|
|
struct cgroup *cont)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
|
|
|
|
return mem_cgroup_force_empty(memcg, false);
|
|
}
|
|
|
|
static void mem_cgroup_destroy(struct cgroup_subsys *ss,
|
|
struct cgroup *cont)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
|
|
|
|
kmem_cgroup_destroy(ss, cont);
|
|
|
|
mem_cgroup_put(memcg);
|
|
}
|
|
|
|
static int mem_cgroup_populate(struct cgroup_subsys *ss,
|
|
struct cgroup *cont)
|
|
{
|
|
int ret;
|
|
|
|
ret = cgroup_add_files(cont, ss, mem_cgroup_files,
|
|
ARRAY_SIZE(mem_cgroup_files));
|
|
|
|
if (!ret)
|
|
ret = register_memsw_files(cont, ss);
|
|
|
|
if (!ret)
|
|
ret = register_kmem_files(cont, ss);
|
|
|
|
return ret;
|
|
}
|
|
|
|
#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;
|
|
}
|
|
|
|
/**
|
|
* is_target_pte_for_mc - check a pte whether it is valid for move 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, /* not used */
|
|
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() || page_mapcount(page) > 2)
|
|
return NULL;
|
|
} else if (!move_file())
|
|
/* we ignore mapcount for file pages */
|
|
return NULL;
|
|
if (!get_page_unless_zero(page))
|
|
return NULL;
|
|
|
|
return page;
|
|
}
|
|
|
|
static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent, swp_entry_t *entry)
|
|
{
|
|
int usage_count;
|
|
struct page *page = NULL;
|
|
swp_entry_t ent = pte_to_swp_entry(ptent);
|
|
|
|
if (!move_anon() || non_swap_entry(ent))
|
|
return NULL;
|
|
usage_count = mem_cgroup_count_swap_user(ent, &page);
|
|
if (usage_count > 1) { /* we don't move shared anon */
|
|
if (page)
|
|
put_page(page);
|
|
return NULL;
|
|
}
|
|
if (do_swap_account)
|
|
entry->val = ent.val;
|
|
|
|
return page;
|
|
}
|
|
|
|
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 inode *inode;
|
|
struct address_space *mapping;
|
|
pgoff_t pgoff;
|
|
|
|
if (!vma->vm_file) /* anonymous vma */
|
|
return NULL;
|
|
if (!move_file())
|
|
return NULL;
|
|
|
|
inode = vma->vm_file->f_path.dentry->d_inode;
|
|
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(&swapper_space, swap.val);
|
|
}
|
|
#endif
|
|
return page;
|
|
}
|
|
|
|
static int is_target_pte_for_mc(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent, union mc_target *target)
|
|
{
|
|
struct page *page = NULL;
|
|
struct page_cgroup *pc;
|
|
int ret = 0;
|
|
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 0;
|
|
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 &&
|
|
css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) {
|
|
ret = MC_TARGET_SWAP;
|
|
if (target)
|
|
target->ent = ent;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
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;
|
|
|
|
split_huge_page_pmd(walk->mm, pmd);
|
|
|
|
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
|
|
for (; addr != end; pte++, addr += PAGE_SIZE)
|
|
if (is_target_pte_for_mc(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;
|
|
|
|
/* 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);
|
|
__mem_cgroup_put(mc.from, mc.moved_swap);
|
|
|
|
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 mem_cgroup_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 *ss,
|
|
struct cgroup *cgroup,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
struct task_struct *p = cgroup_taskset_first(tset);
|
|
int ret = 0;
|
|
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgroup);
|
|
|
|
if (memcg->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;
|
|
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 *ss,
|
|
struct cgroup *cgroup,
|
|
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;
|
|
|
|
split_huge_page_pmd(walk->mm, pmd);
|
|
retry:
|
|
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
|
|
for (; addr != end; addr += PAGE_SIZE) {
|
|
pte_t ptent = *(pte++);
|
|
union mc_target target;
|
|
int type;
|
|
struct page *page;
|
|
struct page_cgroup *pc;
|
|
swp_entry_t ent;
|
|
|
|
if (!mc.precharge)
|
|
break;
|
|
|
|
type = is_target_pte_for_mc(vma, addr, ptent, &target);
|
|
switch (type) {
|
|
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, false)) {
|
|
mc.precharge--;
|
|
/* we uncharge from mc.from later. */
|
|
mc.moved_charge++;
|
|
}
|
|
putback_lru_page(page);
|
|
put: /* is_target_pte_for_mc() 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, false)) {
|
|
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 *ss,
|
|
struct cgroup *cont,
|
|
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);
|
|
put_swap_token(mm);
|
|
mmput(mm);
|
|
}
|
|
if (mc.to)
|
|
mem_cgroup_clear_mc();
|
|
}
|
|
#else /* !CONFIG_MMU */
|
|
static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
|
|
struct cgroup *cgroup,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
return 0;
|
|
}
|
|
static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
|
|
struct cgroup *cgroup,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
}
|
|
static void mem_cgroup_move_task(struct cgroup_subsys *ss,
|
|
struct cgroup *cont,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
struct cgroup_subsys mem_cgroup_subsys = {
|
|
.name = "memory",
|
|
.subsys_id = mem_cgroup_subsys_id,
|
|
.create = mem_cgroup_create,
|
|
.pre_destroy = mem_cgroup_pre_destroy,
|
|
.destroy = mem_cgroup_destroy,
|
|
.populate = mem_cgroup_populate,
|
|
.can_attach = mem_cgroup_can_attach,
|
|
.cancel_attach = mem_cgroup_cancel_attach,
|
|
.attach = mem_cgroup_move_task,
|
|
.early_init = 0,
|
|
.use_id = 1,
|
|
};
|
|
|
|
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
|
|
static int __init enable_swap_account(char *s)
|
|
{
|
|
/* consider enabled if no parameter or 1 is given */
|
|
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);
|
|
|
|
#endif
|