![David Rientjes](/assets/img/avatar_default.png)
mm_cgroup() is exclusively used to test whether an mm's mem_cgroup pointer is pointing to a specific cgroup. Instead of returning the pointer, we can just do the test itself in a new macro: vm_match_cgroup(mm, cgroup) returns non-zero if the mm's mem_cgroup points to cgroup. Otherwise it returns zero. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1193 lines
29 KiB
C
1193 lines
29 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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* 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/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/swap.h>
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#include <linux/spinlock.h>
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#include <linux/fs.h>
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#include <linux/seq_file.h>
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#include <asm/uaccess.h>
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struct cgroup_subsys mem_cgroup_subsys;
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static const int MEM_CGROUP_RECLAIM_RETRIES = 5;
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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 rss */
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MEM_CGROUP_STAT_NSTATS,
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};
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struct mem_cgroup_stat_cpu {
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s64 count[MEM_CGROUP_STAT_NSTATS];
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} ____cacheline_aligned_in_smp;
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struct mem_cgroup_stat {
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struct mem_cgroup_stat_cpu cpustat[NR_CPUS];
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};
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/*
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* For accounting under irq disable, no need for increment preempt count.
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*/
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static void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat *stat,
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enum mem_cgroup_stat_index idx, int val)
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{
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int cpu = smp_processor_id();
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stat->cpustat[cpu].count[idx] += val;
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}
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static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat,
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enum mem_cgroup_stat_index idx)
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{
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int cpu;
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s64 ret = 0;
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for_each_possible_cpu(cpu)
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ret += stat->cpustat[cpu].count[idx];
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return ret;
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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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enum mem_cgroup_zstat_index {
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MEM_CGROUP_ZSTAT_ACTIVE,
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MEM_CGROUP_ZSTAT_INACTIVE,
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NR_MEM_CGROUP_ZSTAT,
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};
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struct mem_cgroup_per_zone {
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/*
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* spin_lock to protect the per cgroup LRU
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*/
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spinlock_t lru_lock;
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struct list_head active_list;
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struct list_head inactive_list;
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unsigned long count[NR_MEM_CGROUP_ZSTAT];
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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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* 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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* 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 prev_priority; /* for recording reclaim priority */
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/*
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* statistics.
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*/
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struct mem_cgroup_stat stat;
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};
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/*
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* We use the lower bit of the page->page_cgroup pointer as a bit spin
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* lock. We need to ensure that page->page_cgroup is atleast two
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* byte aligned (based on comments from Nick Piggin)
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*/
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#define PAGE_CGROUP_LOCK_BIT 0x0
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#define PAGE_CGROUP_LOCK (1 << PAGE_CGROUP_LOCK_BIT)
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/*
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* A page_cgroup page is associated with every page descriptor. The
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* page_cgroup helps us identify information about the cgroup
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*/
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struct page_cgroup {
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struct list_head lru; /* per cgroup LRU list */
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struct page *page;
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struct mem_cgroup *mem_cgroup;
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atomic_t ref_cnt; /* Helpful when pages move b/w */
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/* mapped and cached states */
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int flags;
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};
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#define PAGE_CGROUP_FLAG_CACHE (0x1) /* charged as cache */
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#define PAGE_CGROUP_FLAG_ACTIVE (0x2) /* page is active in this cgroup */
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static inline int page_cgroup_nid(struct page_cgroup *pc)
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{
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return page_to_nid(pc->page);
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}
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static inline enum zone_type page_cgroup_zid(struct page_cgroup *pc)
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{
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return page_zonenum(pc->page);
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}
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enum {
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MEM_CGROUP_TYPE_UNSPEC = 0,
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MEM_CGROUP_TYPE_MAPPED,
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MEM_CGROUP_TYPE_CACHED,
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MEM_CGROUP_TYPE_ALL,
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MEM_CGROUP_TYPE_MAX,
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};
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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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};
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/*
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* Always modified under lru lock. Then, not necessary to preempt_disable()
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*/
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static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, int flags,
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bool charge)
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{
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int val = (charge)? 1 : -1;
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struct mem_cgroup_stat *stat = &mem->stat;
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VM_BUG_ON(!irqs_disabled());
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if (flags & PAGE_CGROUP_FLAG_CACHE)
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__mem_cgroup_stat_add_safe(stat,
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MEM_CGROUP_STAT_CACHE, val);
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else
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__mem_cgroup_stat_add_safe(stat, MEM_CGROUP_STAT_RSS, val);
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}
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static inline struct mem_cgroup_per_zone *
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mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
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{
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BUG_ON(!mem->info.nodeinfo[nid]);
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return &mem->info.nodeinfo[nid]->zoneinfo[zid];
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}
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static inline struct mem_cgroup_per_zone *
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page_cgroup_zoneinfo(struct page_cgroup *pc)
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{
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struct mem_cgroup *mem = pc->mem_cgroup;
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int nid = page_cgroup_nid(pc);
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int zid = page_cgroup_zid(pc);
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return mem_cgroup_zoneinfo(mem, nid, zid);
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}
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static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup *mem,
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enum mem_cgroup_zstat_index idx)
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{
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int nid, zid;
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struct mem_cgroup_per_zone *mz;
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u64 total = 0;
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for_each_online_node(nid)
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for (zid = 0; zid < MAX_NR_ZONES; zid++) {
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mz = mem_cgroup_zoneinfo(mem, nid, zid);
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total += MEM_CGROUP_ZSTAT(mz, idx);
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}
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return total;
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}
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static struct mem_cgroup init_mem_cgroup;
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static inline
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struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
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{
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return container_of(cgroup_subsys_state(cont,
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mem_cgroup_subsys_id), struct mem_cgroup,
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css);
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}
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static inline
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struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
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{
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return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
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struct mem_cgroup, css);
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}
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void mm_init_cgroup(struct mm_struct *mm, struct task_struct *p)
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{
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struct mem_cgroup *mem;
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mem = mem_cgroup_from_task(p);
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css_get(&mem->css);
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mm->mem_cgroup = mem;
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}
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void mm_free_cgroup(struct mm_struct *mm)
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{
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css_put(&mm->mem_cgroup->css);
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}
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static inline int page_cgroup_locked(struct page *page)
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{
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return bit_spin_is_locked(PAGE_CGROUP_LOCK_BIT,
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&page->page_cgroup);
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}
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void page_assign_page_cgroup(struct page *page, struct page_cgroup *pc)
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{
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int locked;
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/*
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* While resetting the page_cgroup we might not hold the
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* page_cgroup lock. free_hot_cold_page() is an example
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* of such a scenario
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*/
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if (pc)
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VM_BUG_ON(!page_cgroup_locked(page));
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locked = (page->page_cgroup & PAGE_CGROUP_LOCK);
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page->page_cgroup = ((unsigned long)pc | locked);
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}
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struct page_cgroup *page_get_page_cgroup(struct page *page)
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{
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return (struct page_cgroup *)
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(page->page_cgroup & ~PAGE_CGROUP_LOCK);
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}
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static void __always_inline lock_page_cgroup(struct page *page)
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{
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bit_spin_lock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
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VM_BUG_ON(!page_cgroup_locked(page));
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}
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static void __always_inline unlock_page_cgroup(struct page *page)
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{
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bit_spin_unlock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
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}
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/*
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* Tie new page_cgroup to struct page under lock_page_cgroup()
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* This can fail if the page has been tied to a page_cgroup.
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* If success, returns 0.
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*/
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static int page_cgroup_assign_new_page_cgroup(struct page *page,
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struct page_cgroup *pc)
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{
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int ret = 0;
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lock_page_cgroup(page);
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if (!page_get_page_cgroup(page))
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page_assign_page_cgroup(page, pc);
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else /* A page is tied to other pc. */
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ret = 1;
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unlock_page_cgroup(page);
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return ret;
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}
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/*
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* Clear page->page_cgroup member under lock_page_cgroup().
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* If given "pc" value is different from one page->page_cgroup,
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* page->cgroup is not cleared.
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* Returns a value of page->page_cgroup at lock taken.
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* A can can detect failure of clearing by following
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* clear_page_cgroup(page, pc) == pc
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*/
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static struct page_cgroup *clear_page_cgroup(struct page *page,
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struct page_cgroup *pc)
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{
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struct page_cgroup *ret;
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/* lock and clear */
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lock_page_cgroup(page);
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ret = page_get_page_cgroup(page);
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if (likely(ret == pc))
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page_assign_page_cgroup(page, NULL);
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unlock_page_cgroup(page);
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return ret;
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}
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static void __mem_cgroup_remove_list(struct page_cgroup *pc)
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{
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int from = pc->flags & PAGE_CGROUP_FLAG_ACTIVE;
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struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc);
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if (from)
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MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) -= 1;
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else
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MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) -= 1;
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mem_cgroup_charge_statistics(pc->mem_cgroup, pc->flags, false);
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list_del_init(&pc->lru);
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}
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static void __mem_cgroup_add_list(struct page_cgroup *pc)
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{
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int to = pc->flags & PAGE_CGROUP_FLAG_ACTIVE;
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struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc);
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if (!to) {
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MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) += 1;
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list_add(&pc->lru, &mz->inactive_list);
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} else {
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MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) += 1;
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list_add(&pc->lru, &mz->active_list);
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}
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mem_cgroup_charge_statistics(pc->mem_cgroup, pc->flags, true);
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}
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static void __mem_cgroup_move_lists(struct page_cgroup *pc, bool active)
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{
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int from = pc->flags & PAGE_CGROUP_FLAG_ACTIVE;
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struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc);
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if (from)
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MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) -= 1;
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else
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MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) -= 1;
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if (active) {
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MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) += 1;
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pc->flags |= PAGE_CGROUP_FLAG_ACTIVE;
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list_move(&pc->lru, &mz->active_list);
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} else {
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MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) += 1;
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pc->flags &= ~PAGE_CGROUP_FLAG_ACTIVE;
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list_move(&pc->lru, &mz->inactive_list);
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}
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}
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int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
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{
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int ret;
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task_lock(task);
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ret = task->mm && vm_match_cgroup(task->mm, mem);
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task_unlock(task);
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return ret;
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}
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/*
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* This routine assumes that the appropriate zone's lru lock is already held
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*/
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void mem_cgroup_move_lists(struct page_cgroup *pc, bool active)
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{
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struct mem_cgroup_per_zone *mz;
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unsigned long flags;
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if (!pc)
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return;
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mz = page_cgroup_zoneinfo(pc);
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spin_lock_irqsave(&mz->lru_lock, flags);
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__mem_cgroup_move_lists(pc, active);
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spin_unlock_irqrestore(&mz->lru_lock, flags);
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}
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/*
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* Calculate mapped_ratio under memory controller. This will be used in
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* vmscan.c for deteremining we have to reclaim mapped pages.
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*/
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int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
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{
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long total, rss;
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/*
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* usage is recorded in bytes. But, here, we assume the number of
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* physical pages can be represented by "long" on any arch.
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*/
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total = (long) (mem->res.usage >> PAGE_SHIFT) + 1L;
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rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
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return (int)((rss * 100L) / total);
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}
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/*
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* This function is called from vmscan.c. In page reclaiming loop. balance
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* between active and inactive list is calculated. For memory controller
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* page reclaiming, we should use using mem_cgroup's imbalance rather than
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* zone's global lru imbalance.
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*/
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long mem_cgroup_reclaim_imbalance(struct mem_cgroup *mem)
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{
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unsigned long active, inactive;
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/* active and inactive are the number of pages. 'long' is ok.*/
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active = mem_cgroup_get_all_zonestat(mem, MEM_CGROUP_ZSTAT_ACTIVE);
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inactive = mem_cgroup_get_all_zonestat(mem, MEM_CGROUP_ZSTAT_INACTIVE);
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return (long) (active / (inactive + 1));
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}
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/*
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* prev_priority control...this will be used in memory reclaim path.
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*/
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int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
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{
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return mem->prev_priority;
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}
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void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority)
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{
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if (priority < mem->prev_priority)
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mem->prev_priority = priority;
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}
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void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority)
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{
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mem->prev_priority = priority;
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}
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/*
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* Calculate # of pages to be scanned in this priority/zone.
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* See also vmscan.c
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*
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* priority starts from "DEF_PRIORITY" and decremented in each loop.
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* (see include/linux/mmzone.h)
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*/
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long mem_cgroup_calc_reclaim_active(struct mem_cgroup *mem,
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struct zone *zone, int priority)
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{
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long nr_active;
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int nid = zone->zone_pgdat->node_id;
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int zid = zone_idx(zone);
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struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(mem, nid, zid);
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nr_active = MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE);
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return (nr_active >> priority);
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}
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|
|
long mem_cgroup_calc_reclaim_inactive(struct mem_cgroup *mem,
|
|
struct zone *zone, int priority)
|
|
{
|
|
long nr_inactive;
|
|
int nid = zone->zone_pgdat->node_id;
|
|
int zid = zone_idx(zone);
|
|
struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(mem, nid, zid);
|
|
|
|
nr_inactive = MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE);
|
|
|
|
return (nr_inactive >> priority);
|
|
}
|
|
|
|
unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
|
|
struct list_head *dst,
|
|
unsigned long *scanned, int order,
|
|
int mode, struct zone *z,
|
|
struct mem_cgroup *mem_cont,
|
|
int active)
|
|
{
|
|
unsigned long nr_taken = 0;
|
|
struct page *page;
|
|
unsigned long scan;
|
|
LIST_HEAD(pc_list);
|
|
struct list_head *src;
|
|
struct page_cgroup *pc, *tmp;
|
|
int nid = z->zone_pgdat->node_id;
|
|
int zid = zone_idx(z);
|
|
struct mem_cgroup_per_zone *mz;
|
|
|
|
mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
|
|
if (active)
|
|
src = &mz->active_list;
|
|
else
|
|
src = &mz->inactive_list;
|
|
|
|
|
|
spin_lock(&mz->lru_lock);
|
|
scan = 0;
|
|
list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
|
|
if (scan >= nr_to_scan)
|
|
break;
|
|
page = pc->page;
|
|
VM_BUG_ON(!pc);
|
|
|
|
if (unlikely(!PageLRU(page)))
|
|
continue;
|
|
|
|
if (PageActive(page) && !active) {
|
|
__mem_cgroup_move_lists(pc, true);
|
|
continue;
|
|
}
|
|
if (!PageActive(page) && active) {
|
|
__mem_cgroup_move_lists(pc, false);
|
|
continue;
|
|
}
|
|
|
|
scan++;
|
|
list_move(&pc->lru, &pc_list);
|
|
|
|
if (__isolate_lru_page(page, mode) == 0) {
|
|
list_move(&page->lru, dst);
|
|
nr_taken++;
|
|
}
|
|
}
|
|
|
|
list_splice(&pc_list, src);
|
|
spin_unlock(&mz->lru_lock);
|
|
|
|
*scanned = scan;
|
|
return nr_taken;
|
|
}
|
|
|
|
/*
|
|
* 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 *mem;
|
|
struct page_cgroup *pc;
|
|
unsigned long flags;
|
|
unsigned long nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
|
|
struct mem_cgroup_per_zone *mz;
|
|
|
|
/*
|
|
* Should page_cgroup's go to their own slab?
|
|
* One could optimize the performance of the charging routine
|
|
* by saving a bit in the page_flags and using it as a lock
|
|
* to see if the cgroup page already has a page_cgroup associated
|
|
* with it
|
|
*/
|
|
retry:
|
|
if (page) {
|
|
lock_page_cgroup(page);
|
|
pc = page_get_page_cgroup(page);
|
|
/*
|
|
* The page_cgroup exists and
|
|
* the page has already been accounted.
|
|
*/
|
|
if (pc) {
|
|
if (unlikely(!atomic_inc_not_zero(&pc->ref_cnt))) {
|
|
/* this page is under being uncharged ? */
|
|
unlock_page_cgroup(page);
|
|
cpu_relax();
|
|
goto retry;
|
|
} else {
|
|
unlock_page_cgroup(page);
|
|
goto done;
|
|
}
|
|
}
|
|
unlock_page_cgroup(page);
|
|
}
|
|
|
|
pc = kzalloc(sizeof(struct page_cgroup), gfp_mask);
|
|
if (pc == NULL)
|
|
goto err;
|
|
|
|
/*
|
|
* 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 (!mm)
|
|
mm = &init_mm;
|
|
|
|
rcu_read_lock();
|
|
mem = rcu_dereference(mm->mem_cgroup);
|
|
/*
|
|
* For every charge from the cgroup, increment reference
|
|
* count
|
|
*/
|
|
css_get(&mem->css);
|
|
rcu_read_unlock();
|
|
|
|
/*
|
|
* If we created the page_cgroup, we should free it on exceeding
|
|
* the cgroup limit.
|
|
*/
|
|
while (res_counter_charge(&mem->res, PAGE_SIZE)) {
|
|
if (!(gfp_mask & __GFP_WAIT))
|
|
goto out;
|
|
|
|
if (try_to_free_mem_cgroup_pages(mem, gfp_mask))
|
|
continue;
|
|
|
|
/*
|
|
* try_to_free_mem_cgroup_pages() might not give us a full
|
|
* picture of reclaim. Some pages are reclaimed and might be
|
|
* moved to swap cache or just unmapped from the cgroup.
|
|
* Check the limit again to see if the reclaim reduced the
|
|
* current usage of the cgroup before giving up
|
|
*/
|
|
if (res_counter_check_under_limit(&mem->res))
|
|
continue;
|
|
|
|
if (!nr_retries--) {
|
|
mem_cgroup_out_of_memory(mem, gfp_mask);
|
|
goto out;
|
|
}
|
|
congestion_wait(WRITE, HZ/10);
|
|
}
|
|
|
|
atomic_set(&pc->ref_cnt, 1);
|
|
pc->mem_cgroup = mem;
|
|
pc->page = page;
|
|
pc->flags = PAGE_CGROUP_FLAG_ACTIVE;
|
|
if (ctype == MEM_CGROUP_CHARGE_TYPE_CACHE)
|
|
pc->flags |= PAGE_CGROUP_FLAG_CACHE;
|
|
|
|
if (!page || page_cgroup_assign_new_page_cgroup(page, pc)) {
|
|
/*
|
|
* Another charge has been added to this page already.
|
|
* We take lock_page_cgroup(page) again and read
|
|
* page->cgroup, increment refcnt.... just retry is OK.
|
|
*/
|
|
res_counter_uncharge(&mem->res, PAGE_SIZE);
|
|
css_put(&mem->css);
|
|
kfree(pc);
|
|
if (!page)
|
|
goto done;
|
|
goto retry;
|
|
}
|
|
|
|
mz = page_cgroup_zoneinfo(pc);
|
|
spin_lock_irqsave(&mz->lru_lock, flags);
|
|
/* Update statistics vector */
|
|
__mem_cgroup_add_list(pc);
|
|
spin_unlock_irqrestore(&mz->lru_lock, flags);
|
|
|
|
done:
|
|
return 0;
|
|
out:
|
|
css_put(&mem->css);
|
|
kfree(pc);
|
|
err:
|
|
return -ENOMEM;
|
|
}
|
|
|
|
int mem_cgroup_charge(struct page *page, struct mm_struct *mm,
|
|
gfp_t gfp_mask)
|
|
{
|
|
return mem_cgroup_charge_common(page, mm, gfp_mask,
|
|
MEM_CGROUP_CHARGE_TYPE_MAPPED);
|
|
}
|
|
|
|
/*
|
|
* See if the cached pages should be charged at all?
|
|
*/
|
|
int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
|
|
gfp_t gfp_mask)
|
|
{
|
|
int ret = 0;
|
|
if (!mm)
|
|
mm = &init_mm;
|
|
|
|
ret = mem_cgroup_charge_common(page, mm, gfp_mask,
|
|
MEM_CGROUP_CHARGE_TYPE_CACHE);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Uncharging is always a welcome operation, we never complain, simply
|
|
* uncharge. This routine should be called with lock_page_cgroup held
|
|
*/
|
|
void mem_cgroup_uncharge(struct page_cgroup *pc)
|
|
{
|
|
struct mem_cgroup *mem;
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct page *page;
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* Check if our page_cgroup is valid
|
|
*/
|
|
if (!pc)
|
|
return;
|
|
|
|
if (atomic_dec_and_test(&pc->ref_cnt)) {
|
|
page = pc->page;
|
|
mz = page_cgroup_zoneinfo(pc);
|
|
/*
|
|
* get page->cgroup and clear it under lock.
|
|
* force_empty can drop page->cgroup without checking refcnt.
|
|
*/
|
|
unlock_page_cgroup(page);
|
|
if (clear_page_cgroup(page, pc) == pc) {
|
|
mem = pc->mem_cgroup;
|
|
css_put(&mem->css);
|
|
res_counter_uncharge(&mem->res, PAGE_SIZE);
|
|
spin_lock_irqsave(&mz->lru_lock, flags);
|
|
__mem_cgroup_remove_list(pc);
|
|
spin_unlock_irqrestore(&mz->lru_lock, flags);
|
|
kfree(pc);
|
|
}
|
|
lock_page_cgroup(page);
|
|
}
|
|
}
|
|
|
|
void mem_cgroup_uncharge_page(struct page *page)
|
|
{
|
|
lock_page_cgroup(page);
|
|
mem_cgroup_uncharge(page_get_page_cgroup(page));
|
|
unlock_page_cgroup(page);
|
|
}
|
|
|
|
/*
|
|
* Returns non-zero if a page (under migration) has valid page_cgroup member.
|
|
* Refcnt of page_cgroup is incremented.
|
|
*/
|
|
|
|
int mem_cgroup_prepare_migration(struct page *page)
|
|
{
|
|
struct page_cgroup *pc;
|
|
int ret = 0;
|
|
lock_page_cgroup(page);
|
|
pc = page_get_page_cgroup(page);
|
|
if (pc && atomic_inc_not_zero(&pc->ref_cnt))
|
|
ret = 1;
|
|
unlock_page_cgroup(page);
|
|
return ret;
|
|
}
|
|
|
|
void mem_cgroup_end_migration(struct page *page)
|
|
{
|
|
struct page_cgroup *pc;
|
|
|
|
lock_page_cgroup(page);
|
|
pc = page_get_page_cgroup(page);
|
|
mem_cgroup_uncharge(pc);
|
|
unlock_page_cgroup(page);
|
|
}
|
|
/*
|
|
* We know both *page* and *newpage* are now not-on-LRU and Pg_locked.
|
|
* And no race with uncharge() routines because page_cgroup for *page*
|
|
* has extra one reference by mem_cgroup_prepare_migration.
|
|
*/
|
|
|
|
void mem_cgroup_page_migration(struct page *page, struct page *newpage)
|
|
{
|
|
struct page_cgroup *pc;
|
|
struct mem_cgroup *mem;
|
|
unsigned long flags;
|
|
struct mem_cgroup_per_zone *mz;
|
|
retry:
|
|
pc = page_get_page_cgroup(page);
|
|
if (!pc)
|
|
return;
|
|
mem = pc->mem_cgroup;
|
|
mz = page_cgroup_zoneinfo(pc);
|
|
if (clear_page_cgroup(page, pc) != pc)
|
|
goto retry;
|
|
spin_lock_irqsave(&mz->lru_lock, flags);
|
|
|
|
__mem_cgroup_remove_list(pc);
|
|
spin_unlock_irqrestore(&mz->lru_lock, flags);
|
|
|
|
pc->page = newpage;
|
|
lock_page_cgroup(newpage);
|
|
page_assign_page_cgroup(newpage, pc);
|
|
unlock_page_cgroup(newpage);
|
|
|
|
mz = page_cgroup_zoneinfo(pc);
|
|
spin_lock_irqsave(&mz->lru_lock, flags);
|
|
__mem_cgroup_add_list(pc);
|
|
spin_unlock_irqrestore(&mz->lru_lock, flags);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* This routine traverse page_cgroup in given list and drop them all.
|
|
* This routine ignores page_cgroup->ref_cnt.
|
|
* *And* this routine doesn't reclaim page itself, just removes page_cgroup.
|
|
*/
|
|
#define FORCE_UNCHARGE_BATCH (128)
|
|
static void
|
|
mem_cgroup_force_empty_list(struct mem_cgroup *mem,
|
|
struct mem_cgroup_per_zone *mz,
|
|
int active)
|
|
{
|
|
struct page_cgroup *pc;
|
|
struct page *page;
|
|
int count;
|
|
unsigned long flags;
|
|
struct list_head *list;
|
|
|
|
if (active)
|
|
list = &mz->active_list;
|
|
else
|
|
list = &mz->inactive_list;
|
|
|
|
if (list_empty(list))
|
|
return;
|
|
retry:
|
|
count = FORCE_UNCHARGE_BATCH;
|
|
spin_lock_irqsave(&mz->lru_lock, flags);
|
|
|
|
while (--count && !list_empty(list)) {
|
|
pc = list_entry(list->prev, struct page_cgroup, lru);
|
|
page = pc->page;
|
|
/* Avoid race with charge */
|
|
atomic_set(&pc->ref_cnt, 0);
|
|
if (clear_page_cgroup(page, pc) == pc) {
|
|
css_put(&mem->css);
|
|
res_counter_uncharge(&mem->res, PAGE_SIZE);
|
|
__mem_cgroup_remove_list(pc);
|
|
kfree(pc);
|
|
} else /* being uncharged ? ...do relax */
|
|
break;
|
|
}
|
|
spin_unlock_irqrestore(&mz->lru_lock, flags);
|
|
if (!list_empty(list)) {
|
|
cond_resched();
|
|
goto retry;
|
|
}
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* make mem_cgroup's charge to be 0 if there is no task.
|
|
* This enables deleting this mem_cgroup.
|
|
*/
|
|
|
|
int mem_cgroup_force_empty(struct mem_cgroup *mem)
|
|
{
|
|
int ret = -EBUSY;
|
|
int node, zid;
|
|
css_get(&mem->css);
|
|
/*
|
|
* page reclaim code (kswapd etc..) will move pages between
|
|
` * active_list <-> inactive_list while we don't take a lock.
|
|
* So, we have to do loop here until all lists are empty.
|
|
*/
|
|
while (mem->res.usage > 0) {
|
|
if (atomic_read(&mem->css.cgroup->count) > 0)
|
|
goto out;
|
|
for_each_node_state(node, N_POSSIBLE)
|
|
for (zid = 0; zid < MAX_NR_ZONES; zid++) {
|
|
struct mem_cgroup_per_zone *mz;
|
|
mz = mem_cgroup_zoneinfo(mem, node, zid);
|
|
/* drop all page_cgroup in active_list */
|
|
mem_cgroup_force_empty_list(mem, mz, 1);
|
|
/* drop all page_cgroup in inactive_list */
|
|
mem_cgroup_force_empty_list(mem, mz, 0);
|
|
}
|
|
}
|
|
ret = 0;
|
|
out:
|
|
css_put(&mem->css);
|
|
return ret;
|
|
}
|
|
|
|
|
|
|
|
int mem_cgroup_write_strategy(char *buf, unsigned long long *tmp)
|
|
{
|
|
*tmp = memparse(buf, &buf);
|
|
if (*buf != '\0')
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Round up the value to the closest page size
|
|
*/
|
|
*tmp = ((*tmp + PAGE_SIZE - 1) >> PAGE_SHIFT) << PAGE_SHIFT;
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t mem_cgroup_read(struct cgroup *cont,
|
|
struct cftype *cft, struct file *file,
|
|
char __user *userbuf, size_t nbytes, loff_t *ppos)
|
|
{
|
|
return res_counter_read(&mem_cgroup_from_cont(cont)->res,
|
|
cft->private, userbuf, nbytes, ppos,
|
|
NULL);
|
|
}
|
|
|
|
static ssize_t mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
|
|
struct file *file, const char __user *userbuf,
|
|
size_t nbytes, loff_t *ppos)
|
|
{
|
|
return res_counter_write(&mem_cgroup_from_cont(cont)->res,
|
|
cft->private, userbuf, nbytes, ppos,
|
|
mem_cgroup_write_strategy);
|
|
}
|
|
|
|
static ssize_t mem_force_empty_write(struct cgroup *cont,
|
|
struct cftype *cft, struct file *file,
|
|
const char __user *userbuf,
|
|
size_t nbytes, loff_t *ppos)
|
|
{
|
|
struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
|
|
int ret;
|
|
ret = mem_cgroup_force_empty(mem);
|
|
if (!ret)
|
|
ret = nbytes;
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Note: This should be removed if cgroup supports write-only file.
|
|
*/
|
|
|
|
static ssize_t mem_force_empty_read(struct cgroup *cont,
|
|
struct cftype *cft,
|
|
struct file *file, char __user *userbuf,
|
|
size_t nbytes, loff_t *ppos)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
|
|
|
|
static const struct mem_cgroup_stat_desc {
|
|
const char *msg;
|
|
u64 unit;
|
|
} mem_cgroup_stat_desc[] = {
|
|
[MEM_CGROUP_STAT_CACHE] = { "cache", PAGE_SIZE, },
|
|
[MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, },
|
|
};
|
|
|
|
static int mem_control_stat_show(struct seq_file *m, void *arg)
|
|
{
|
|
struct cgroup *cont = m->private;
|
|
struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont);
|
|
struct mem_cgroup_stat *stat = &mem_cont->stat;
|
|
int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(stat->cpustat[0].count); i++) {
|
|
s64 val;
|
|
|
|
val = mem_cgroup_read_stat(stat, i);
|
|
val *= mem_cgroup_stat_desc[i].unit;
|
|
seq_printf(m, "%s %lld\n", mem_cgroup_stat_desc[i].msg,
|
|
(long long)val);
|
|
}
|
|
/* showing # of active pages */
|
|
{
|
|
unsigned long active, inactive;
|
|
|
|
inactive = mem_cgroup_get_all_zonestat(mem_cont,
|
|
MEM_CGROUP_ZSTAT_INACTIVE);
|
|
active = mem_cgroup_get_all_zonestat(mem_cont,
|
|
MEM_CGROUP_ZSTAT_ACTIVE);
|
|
seq_printf(m, "active %ld\n", (active) * PAGE_SIZE);
|
|
seq_printf(m, "inactive %ld\n", (inactive) * PAGE_SIZE);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations mem_control_stat_file_operations = {
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = single_release,
|
|
};
|
|
|
|
static int mem_control_stat_open(struct inode *unused, struct file *file)
|
|
{
|
|
/* XXX __d_cont */
|
|
struct cgroup *cont = file->f_dentry->d_parent->d_fsdata;
|
|
|
|
file->f_op = &mem_control_stat_file_operations;
|
|
return single_open(file, mem_control_stat_show, cont);
|
|
}
|
|
|
|
|
|
|
|
static struct cftype mem_cgroup_files[] = {
|
|
{
|
|
.name = "usage_in_bytes",
|
|
.private = RES_USAGE,
|
|
.read = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "limit_in_bytes",
|
|
.private = RES_LIMIT,
|
|
.write = mem_cgroup_write,
|
|
.read = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "failcnt",
|
|
.private = RES_FAILCNT,
|
|
.read = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "force_empty",
|
|
.write = mem_force_empty_write,
|
|
.read = mem_force_empty_read,
|
|
},
|
|
{
|
|
.name = "stat",
|
|
.open = mem_control_stat_open,
|
|
},
|
|
};
|
|
|
|
static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
|
|
{
|
|
struct mem_cgroup_per_node *pn;
|
|
struct mem_cgroup_per_zone *mz;
|
|
int zone;
|
|
/*
|
|
* 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_HIGH_MEMORY))
|
|
pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, node);
|
|
else
|
|
pn = kmalloc(sizeof(*pn), GFP_KERNEL);
|
|
if (!pn)
|
|
return 1;
|
|
|
|
mem->info.nodeinfo[node] = pn;
|
|
memset(pn, 0, sizeof(*pn));
|
|
|
|
for (zone = 0; zone < MAX_NR_ZONES; zone++) {
|
|
mz = &pn->zoneinfo[zone];
|
|
INIT_LIST_HEAD(&mz->active_list);
|
|
INIT_LIST_HEAD(&mz->inactive_list);
|
|
spin_lock_init(&mz->lru_lock);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
|
|
{
|
|
kfree(mem->info.nodeinfo[node]);
|
|
}
|
|
|
|
|
|
static struct mem_cgroup init_mem_cgroup;
|
|
|
|
static struct cgroup_subsys_state *
|
|
mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
|
|
{
|
|
struct mem_cgroup *mem;
|
|
int node;
|
|
|
|
if (unlikely((cont->parent) == NULL)) {
|
|
mem = &init_mem_cgroup;
|
|
init_mm.mem_cgroup = mem;
|
|
} else
|
|
mem = kzalloc(sizeof(struct mem_cgroup), GFP_KERNEL);
|
|
|
|
if (mem == NULL)
|
|
return NULL;
|
|
|
|
res_counter_init(&mem->res);
|
|
|
|
memset(&mem->info, 0, sizeof(mem->info));
|
|
|
|
for_each_node_state(node, N_POSSIBLE)
|
|
if (alloc_mem_cgroup_per_zone_info(mem, node))
|
|
goto free_out;
|
|
|
|
return &mem->css;
|
|
free_out:
|
|
for_each_node_state(node, N_POSSIBLE)
|
|
free_mem_cgroup_per_zone_info(mem, node);
|
|
if (cont->parent != NULL)
|
|
kfree(mem);
|
|
return NULL;
|
|
}
|
|
|
|
static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
|
|
struct cgroup *cont)
|
|
{
|
|
struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
|
|
mem_cgroup_force_empty(mem);
|
|
}
|
|
|
|
static void mem_cgroup_destroy(struct cgroup_subsys *ss,
|
|
struct cgroup *cont)
|
|
{
|
|
int node;
|
|
struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
|
|
|
|
for_each_node_state(node, N_POSSIBLE)
|
|
free_mem_cgroup_per_zone_info(mem, node);
|
|
|
|
kfree(mem_cgroup_from_cont(cont));
|
|
}
|
|
|
|
static int mem_cgroup_populate(struct cgroup_subsys *ss,
|
|
struct cgroup *cont)
|
|
{
|
|
return cgroup_add_files(cont, ss, mem_cgroup_files,
|
|
ARRAY_SIZE(mem_cgroup_files));
|
|
}
|
|
|
|
static void mem_cgroup_move_task(struct cgroup_subsys *ss,
|
|
struct cgroup *cont,
|
|
struct cgroup *old_cont,
|
|
struct task_struct *p)
|
|
{
|
|
struct mm_struct *mm;
|
|
struct mem_cgroup *mem, *old_mem;
|
|
|
|
mm = get_task_mm(p);
|
|
if (mm == NULL)
|
|
return;
|
|
|
|
mem = mem_cgroup_from_cont(cont);
|
|
old_mem = mem_cgroup_from_cont(old_cont);
|
|
|
|
if (mem == old_mem)
|
|
goto out;
|
|
|
|
/*
|
|
* Only thread group leaders are allowed to migrate, the mm_struct is
|
|
* in effect owned by the leader
|
|
*/
|
|
if (p->tgid != p->pid)
|
|
goto out;
|
|
|
|
css_get(&mem->css);
|
|
rcu_assign_pointer(mm->mem_cgroup, mem);
|
|
css_put(&old_mem->css);
|
|
|
|
out:
|
|
mmput(mm);
|
|
return;
|
|
}
|
|
|
|
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,
|
|
.attach = mem_cgroup_move_task,
|
|
.early_init = 0,
|
|
};
|