memcontrol.c 53.9 KB
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/* memcontrol.c - Memory Controller
 *
 * Copyright IBM Corporation, 2007
 * Author Balbir Singh <balbir@linux.vnet.ibm.com>
 *
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 * Copyright 2007 OpenVZ SWsoft Inc
 * Author: Pavel Emelianov <xemul@openvz.org>
 *
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 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/res_counter.h>
#include <linux/memcontrol.h>
#include <linux/cgroup.h>
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#include <linux/mm.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>
#include <linux/rcupdate.h>
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#include <linux/mutex.h>
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#include <linux/slab.h>
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#include <linux/swap.h>
#include <linux/spinlock.h>
#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 "internal.h"
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#include <asm/uaccess.h>

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struct cgroup_subsys mem_cgroup_subsys __read_mostly;
#define MEM_CGROUP_RECLAIM_RETRIES	5
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#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
/* Turned on only when memory cgroup is enabled && really_do_swap_account = 0 */
int do_swap_account __read_mostly;
static int really_do_swap_account __initdata = 1; /* for remember boot option*/
#else
#define do_swap_account		(0)
#endif


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/*
 * Statistics for memory cgroup.
 */
enum mem_cgroup_stat_index {
	/*
	 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
	 */
	MEM_CGROUP_STAT_CACHE, 	   /* # of pages charged as cache */
	MEM_CGROUP_STAT_RSS,	   /* # of pages charged as rss */
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	MEM_CGROUP_STAT_PGPGIN_COUNT,	/* # of pages paged in */
	MEM_CGROUP_STAT_PGPGOUT_COUNT,	/* # of pages paged out */
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	MEM_CGROUP_STAT_NSTATS,
};

struct mem_cgroup_stat_cpu {
	s64 count[MEM_CGROUP_STAT_NSTATS];
} ____cacheline_aligned_in_smp;

struct mem_cgroup_stat {
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	struct mem_cgroup_stat_cpu cpustat[0];
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};

/*
 * For accounting under irq disable, no need for increment preempt count.
 */
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static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu *stat,
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		enum mem_cgroup_stat_index idx, int val)
{
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	stat->count[idx] += val;
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}

static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat,
		enum mem_cgroup_stat_index idx)
{
	int cpu;
	s64 ret = 0;
	for_each_possible_cpu(cpu)
		ret += stat->cpustat[cpu].count[idx];
	return ret;
}

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/*
 * per-zone information in memory controller.
 */
struct mem_cgroup_per_zone {
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	/*
	 * spin_lock to protect the per cgroup LRU
	 */
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	struct list_head	lists[NR_LRU_LISTS];
	unsigned long		count[NR_LRU_LISTS];
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	struct zone_reclaim_stat reclaim_stat;
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};
/* Macro for accessing counter */
#define MEM_CGROUP_ZSTAT(mz, idx)	((mz)->count[(idx)])

struct mem_cgroup_per_node {
	struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
};

struct mem_cgroup_lru_info {
	struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
};

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/*
 * The memory controller data structure. The memory controller controls both
 * page cache and RSS per cgroup. We would eventually like to provide
 * statistics based on the statistics developed by Rik Van Riel for clock-pro,
 * to help the administrator determine what knobs to tune.
 *
 * 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
 * no reclaim occurs from a cgroup at it's low water mark, this is
 * a feature that will be implemented much later in the future.
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 */
struct mem_cgroup {
	struct cgroup_subsys_state css;
	/*
	 * the counter to account for memory usage
	 */
	struct res_counter res;
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	/*
	 * the counter to account for mem+swap usage.
	 */
	struct res_counter memsw;
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	/*
	 * Per cgroup active and inactive list, similar to the
	 * per zone LRU lists.
	 */
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	struct mem_cgroup_lru_info info;
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	/*
	  protect against reclaim related member.
	*/
	spinlock_t reclaim_param_lock;

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	int	prev_priority;	/* for recording reclaim priority */
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	/*
	 * While reclaiming in a hiearchy, we cache the last child we
	 * reclaimed from. Protected by cgroup_lock()
	 */
	struct mem_cgroup *last_scanned_child;
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	/*
	 * Should the accounting and control be hierarchical, per subtree?
	 */
	bool use_hierarchy;
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	unsigned long	last_oom_jiffies;
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	int		obsolete;
	atomic_t	refcnt;
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	unsigned int	swappiness;

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	/*
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	 * statistics. This must be placed at the end of memcg.
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	 */
	struct mem_cgroup_stat stat;
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};

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enum charge_type {
	MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
	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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	NR_CHARGE_TYPE,
};

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/* only for here (for easy reading.) */
#define PCGF_CACHE	(1UL << PCG_CACHE)
#define PCGF_USED	(1UL << PCG_USED)
#define PCGF_LOCK	(1UL << PCG_LOCK)
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static const unsigned long
pcg_default_flags[NR_CHARGE_TYPE] = {
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	PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* File Cache */
	PCGF_USED | PCGF_LOCK, /* Anon */
	PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */
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	0, /* FORCE */
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};

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/* for encoding cft->private value on file */
#define _MEM			(0)
#define _MEMSWAP		(1)
#define MEMFILE_PRIVATE(x, val)	(((x) << 16) | (val))
#define MEMFILE_TYPE(val)	(((val) >> 16) & 0xffff)
#define MEMFILE_ATTR(val)	((val) & 0xffff)

static void mem_cgroup_get(struct mem_cgroup *mem);
static void mem_cgroup_put(struct mem_cgroup *mem);

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static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
					 struct page_cgroup *pc,
					 bool charge)
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{
	int val = (charge)? 1 : -1;
	struct mem_cgroup_stat *stat = &mem->stat;
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	struct mem_cgroup_stat_cpu *cpustat;
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	int cpu = get_cpu();
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	cpustat = &stat->cpustat[cpu];
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	if (PageCgroupCache(pc))
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		__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_CACHE, val);
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	else
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		__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_RSS, val);
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	if (charge)
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		__mem_cgroup_stat_add_safe(cpustat,
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				MEM_CGROUP_STAT_PGPGIN_COUNT, 1);
	else
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		__mem_cgroup_stat_add_safe(cpustat,
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				MEM_CGROUP_STAT_PGPGOUT_COUNT, 1);
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	put_cpu();
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}

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static struct mem_cgroup_per_zone *
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mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
{
	return &mem->info.nodeinfo[nid]->zoneinfo[zid];
}

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static struct mem_cgroup_per_zone *
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page_cgroup_zoneinfo(struct page_cgroup *pc)
{
	struct mem_cgroup *mem = pc->mem_cgroup;
	int nid = page_cgroup_nid(pc);
	int zid = page_cgroup_zid(pc);
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	if (!mem)
		return NULL;

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	return mem_cgroup_zoneinfo(mem, nid, zid);
}

static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup *mem,
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					enum lru_list idx)
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{
	int nid, zid;
	struct mem_cgroup_per_zone *mz;
	u64 total = 0;

	for_each_online_node(nid)
		for (zid = 0; zid < MAX_NR_ZONES; zid++) {
			mz = mem_cgroup_zoneinfo(mem, nid, zid);
			total += MEM_CGROUP_ZSTAT(mz, idx);
		}
	return total;
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}

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static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
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{
	return container_of(cgroup_subsys_state(cont,
				mem_cgroup_subsys_id), struct mem_cgroup,
				css);
}

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struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
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{
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	/*
	 * 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;

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	return container_of(task_subsys_state(p, mem_cgroup_subsys_id),
				struct mem_cgroup, css);
}

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/*
 * 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.
 */
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void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
{
	struct page_cgroup *pc;
	struct mem_cgroup *mem;
	struct mem_cgroup_per_zone *mz;
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	if (mem_cgroup_disabled())
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		return;
	pc = lookup_page_cgroup(page);
	/* can happen while we handle swapcache. */
	if (list_empty(&pc->lru))
		return;
	mz = page_cgroup_zoneinfo(pc);
	mem = pc->mem_cgroup;
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	MEM_CGROUP_ZSTAT(mz, lru) -= 1;
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	list_del_init(&pc->lru);
	return;
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}

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void mem_cgroup_del_lru(struct page *page)
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{
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	mem_cgroup_del_lru_list(page, page_lru(page));
}
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void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
{
	struct mem_cgroup_per_zone *mz;
	struct page_cgroup *pc;
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	if (mem_cgroup_disabled())
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		return;
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	pc = lookup_page_cgroup(page);
	smp_rmb();
	/* unused page is not rotated. */
	if (!PageCgroupUsed(pc))
		return;
	mz = page_cgroup_zoneinfo(pc);
	list_move(&pc->lru, &mz->lists[lru]);
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}

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void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
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{
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	struct page_cgroup *pc;
	struct mem_cgroup_per_zone *mz;
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	if (mem_cgroup_disabled())
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		return;
	pc = lookup_page_cgroup(page);
	/* barrier to sync with "charge" */
	smp_rmb();
	if (!PageCgroupUsed(pc))
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		return;
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	mz = page_cgroup_zoneinfo(pc);
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	MEM_CGROUP_ZSTAT(mz, lru) += 1;
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	list_add(&pc->lru, &mz->lists[lru]);
}
/*
 * To add swapcache into LRU. Be careful to all this function.
 * zone->lru_lock shouldn't be held and irq must not be disabled.
 */
static void mem_cgroup_lru_fixup(struct page *page)
{
	if (!isolate_lru_page(page))
		putback_lru_page(page);
}

void mem_cgroup_move_lists(struct page *page,
			   enum lru_list from, enum lru_list to)
{
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	if (mem_cgroup_disabled())
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		return;
	mem_cgroup_del_lru_list(page, from);
	mem_cgroup_add_lru_list(page, to);
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}

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int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
{
	int ret;

	task_lock(task);
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	ret = task->mm && mm_match_cgroup(task->mm, mem);
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	task_unlock(task);
	return ret;
}

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/*
 * Calculate mapped_ratio under memory controller. This will be used in
 * vmscan.c for deteremining we have to reclaim mapped pages.
 */
int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
{
	long total, rss;

	/*
	 * usage is recorded in bytes. But, here, we assume the number of
	 * physical pages can be represented by "long" on any arch.
	 */
	total = (long) (mem->res.usage >> PAGE_SHIFT) + 1L;
	rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
	return (int)((rss * 100L) / total);
}
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/*
 * prev_priority control...this will be used in memory reclaim path.
 */
int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
{
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	int prev_priority;

	spin_lock(&mem->reclaim_param_lock);
	prev_priority = mem->prev_priority;
	spin_unlock(&mem->reclaim_param_lock);

	return prev_priority;
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}

void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority)
{
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	spin_lock(&mem->reclaim_param_lock);
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	if (priority < mem->prev_priority)
		mem->prev_priority = priority;
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	spin_unlock(&mem->reclaim_param_lock);
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}

void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority)
{
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	spin_lock(&mem->reclaim_param_lock);
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	mem->prev_priority = priority;
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	spin_unlock(&mem->reclaim_param_lock);
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}

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static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages)
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{
	unsigned long active;
	unsigned long inactive;
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	unsigned long gb;
	unsigned long inactive_ratio;
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	inactive = mem_cgroup_get_all_zonestat(memcg, LRU_INACTIVE_ANON);
	active = mem_cgroup_get_all_zonestat(memcg, LRU_ACTIVE_ANON);

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	gb = (inactive + active) >> (30 - PAGE_SHIFT);
	if (gb)
		inactive_ratio = int_sqrt(10 * gb);
	else
		inactive_ratio = 1;

	if (present_pages) {
		present_pages[0] = inactive;
		present_pages[1] = active;
	}

	return inactive_ratio;
}

int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg)
{
	unsigned long active;
	unsigned long inactive;
	unsigned long present_pages[2];
	unsigned long inactive_ratio;

	inactive_ratio = calc_inactive_ratio(memcg, present_pages);

	inactive = present_pages[0];
	active = present_pages[1];

	if (inactive * inactive_ratio < active)
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		return 1;

	return 0;
}

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unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
				       struct zone *zone,
				       enum lru_list lru)
{
	int nid = zone->zone_pgdat->node_id;
	int zid = zone_idx(zone);
	struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);

	return MEM_CGROUP_ZSTAT(mz, lru);
}

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struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
						      struct zone *zone)
{
	int nid = zone->zone_pgdat->node_id;
	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);
	mz = page_cgroup_zoneinfo(pc);
	if (!mz)
		return NULL;

	return &mz->reclaim_stat;
}

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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,
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					int active, int file)
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{
	unsigned long nr_taken = 0;
	struct page *page;
	unsigned long scan;
	LIST_HEAD(pc_list);
	struct list_head *src;
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	struct page_cgroup *pc, *tmp;
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	int nid = z->zone_pgdat->node_id;
	int zid = zone_idx(z);
	struct mem_cgroup_per_zone *mz;
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	int lru = LRU_FILE * !!file + !!active;
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	BUG_ON(!mem_cont);
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	mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
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	src = &mz->lists[lru];
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	scan = 0;
	list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
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		if (scan >= nr_to_scan)
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			break;
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		page = pc->page;
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		if (unlikely(!PageCgroupUsed(pc)))
			continue;
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		if (unlikely(!PageLRU(page)))
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			continue;

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		scan++;
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		if (__isolate_lru_page(page, mode, file) == 0) {
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			list_move(&page->lru, dst);
			nr_taken++;
		}
	}

	*scanned = scan;
	return nr_taken;
}

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#define mem_cgroup_from_res_counter(counter, member)	\
	container_of(counter, struct mem_cgroup, member)

/*
 * This routine finds the DFS walk successor. This routine should be
 * called with cgroup_mutex held
 */
static struct mem_cgroup *
mem_cgroup_get_next_node(struct mem_cgroup *curr, struct mem_cgroup *root_mem)
{
	struct cgroup *cgroup, *curr_cgroup, *root_cgroup;

	curr_cgroup = curr->css.cgroup;
	root_cgroup = root_mem->css.cgroup;

	if (!list_empty(&curr_cgroup->children)) {
		/*
		 * Walk down to children
		 */
		mem_cgroup_put(curr);
		cgroup = list_entry(curr_cgroup->children.next,
						struct cgroup, sibling);
		curr = mem_cgroup_from_cont(cgroup);
		mem_cgroup_get(curr);
		goto done;
	}

visit_parent:
	if (curr_cgroup == root_cgroup) {
		mem_cgroup_put(curr);
		curr = root_mem;
		mem_cgroup_get(curr);
		goto done;
	}

	/*
	 * Goto next sibling
	 */
	if (curr_cgroup->sibling.next != &curr_cgroup->parent->children) {
		mem_cgroup_put(curr);
		cgroup = list_entry(curr_cgroup->sibling.next, struct cgroup,
						sibling);
		curr = mem_cgroup_from_cont(cgroup);
		mem_cgroup_get(curr);
		goto done;
	}

	/*
	 * Go up to next parent and next parent's sibling if need be
	 */
	curr_cgroup = curr_cgroup->parent;
	goto visit_parent;

done:
	root_mem->last_scanned_child = curr;
	return curr;
}

/*
 * Visit the first child (need not be the first child as per the ordering
 * of the cgroup list, since we track last_scanned_child) of @mem and use
 * that to reclaim free pages from.
 */
static struct mem_cgroup *
mem_cgroup_get_first_node(struct mem_cgroup *root_mem)
{
	struct cgroup *cgroup;
	struct mem_cgroup *ret;
	bool obsolete = (root_mem->last_scanned_child &&
				root_mem->last_scanned_child->obsolete);

	/*
	 * Scan all children under the mem_cgroup mem
	 */
	cgroup_lock();
	if (list_empty(&root_mem->css.cgroup->children)) {
		ret = root_mem;
		goto done;
	}

	if (!root_mem->last_scanned_child || obsolete) {

		if (obsolete)
			mem_cgroup_put(root_mem->last_scanned_child);

		cgroup = list_first_entry(&root_mem->css.cgroup->children,
				struct cgroup, sibling);
		ret = mem_cgroup_from_cont(cgroup);
		mem_cgroup_get(ret);
	} else
		ret = mem_cgroup_get_next_node(root_mem->last_scanned_child,
						root_mem);

done:
	root_mem->last_scanned_child = ret;
	cgroup_unlock();
	return ret;
}

655 656 657 658 659 660 661 662 663 664 665 666
static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem)
{
	if (do_swap_account) {
		if (res_counter_check_under_limit(&mem->res) &&
			res_counter_check_under_limit(&mem->memsw))
			return true;
	} else
		if (res_counter_check_under_limit(&mem->res))
			return true;
	return false;
}

K
KOSAKI Motohiro 已提交
667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682
static unsigned int get_swappiness(struct mem_cgroup *memcg)
{
	struct cgroup *cgrp = memcg->css.cgroup;
	unsigned int swappiness;

	/* root ? */
	if (cgrp->parent == NULL)
		return vm_swappiness;

	spin_lock(&memcg->reclaim_param_lock);
	swappiness = memcg->swappiness;
	spin_unlock(&memcg->reclaim_param_lock);

	return swappiness;
}

683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702
/*
 * Dance down the hierarchy if needed to reclaim memory. We remember the
 * last child we reclaimed from, so that we don't end up penalizing
 * one child extensively based on its position in the children list.
 *
 * root_mem is the original ancestor that we've been reclaim from.
 */
static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
						gfp_t gfp_mask, bool noswap)
{
	struct mem_cgroup *next_mem;
	int ret = 0;

	/*
	 * Reclaim unconditionally and don't check for return value.
	 * We need to reclaim in the current group and down the tree.
	 * One might think about checking for children before reclaiming,
	 * but there might be left over accounting, even after children
	 * have left.
	 */
K
KOSAKI Motohiro 已提交
703 704
	ret = try_to_free_mem_cgroup_pages(root_mem, gfp_mask, noswap,
					   get_swappiness(root_mem));
705
	if (mem_cgroup_check_under_limit(root_mem))
706
		return 0;
707 708
	if (!root_mem->use_hierarchy)
		return ret;
709 710 711 712 713 714 715 716 717 718 719

	next_mem = mem_cgroup_get_first_node(root_mem);

	while (next_mem != root_mem) {
		if (next_mem->obsolete) {
			mem_cgroup_put(next_mem);
			cgroup_lock();
			next_mem = mem_cgroup_get_first_node(root_mem);
			cgroup_unlock();
			continue;
		}
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KOSAKI Motohiro 已提交
720 721
		ret = try_to_free_mem_cgroup_pages(next_mem, gfp_mask, noswap,
						   get_swappiness(next_mem));
722
		if (mem_cgroup_check_under_limit(root_mem))
723 724 725 726 727 728 729 730
			return 0;
		cgroup_lock();
		next_mem = mem_cgroup_get_next_node(next_mem, root_mem);
		cgroup_unlock();
	}
	return ret;
}

731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746
bool mem_cgroup_oom_called(struct task_struct *task)
{
	bool ret = false;
	struct mem_cgroup *mem;
	struct mm_struct *mm;

	rcu_read_lock();
	mm = task->mm;
	if (!mm)
		mm = &init_mm;
	mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
	if (mem && time_before(jiffies, mem->last_oom_jiffies + HZ/10))
		ret = true;
	rcu_read_unlock();
	return ret;
}
747 748 749
/*
 * Unlike exported interface, "oom" parameter is added. if oom==true,
 * oom-killer can be invoked.
750
 */
751
static int __mem_cgroup_try_charge(struct mm_struct *mm,
752 753
			gfp_t gfp_mask, struct mem_cgroup **memcg,
			bool oom)
754
{
755
	struct mem_cgroup *mem, *mem_over_limit;
756
	int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
757
	struct res_counter *fail_res;
758 759 760 761 762 763 764

	if (unlikely(test_thread_flag(TIF_MEMDIE))) {
		/* Don't account this! */
		*memcg = NULL;
		return 0;
	}

765
	/*
766 767
	 * We always charge the cgroup the mm_struct belongs to.
	 * The mm_struct's mem_cgroup changes on task migration if the
768 769 770
	 * thread group leader migrates. It's possible that mm is not
	 * set, if so charge the init_mm (happens for pagecache usage).
	 */
771
	if (likely(!*memcg)) {
772 773
		rcu_read_lock();
		mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
774 775 776 777
		if (unlikely(!mem)) {
			rcu_read_unlock();
			return 0;
		}
778 779 780 781
		/*
		 * For every charge from the cgroup, increment reference count
		 */
		css_get(&mem->css);
782
		*memcg = mem;
783 784
		rcu_read_unlock();
	} else {
785 786
		mem = *memcg;
		css_get(&mem->css);
787
	}
788

789 790 791
	while (1) {
		int ret;
		bool noswap = false;
792

793
		ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res);
794 795 796
		if (likely(!ret)) {
			if (!do_swap_account)
				break;
797 798
			ret = res_counter_charge(&mem->memsw, PAGE_SIZE,
							&fail_res);
799 800 801 802 803
			if (likely(!ret))
				break;
			/* mem+swap counter fails */
			res_counter_uncharge(&mem->res, PAGE_SIZE);
			noswap = true;
804 805 806 807 808 809 810
			mem_over_limit = mem_cgroup_from_res_counter(fail_res,
									memsw);
		} else
			/* mem counter fails */
			mem_over_limit = mem_cgroup_from_res_counter(fail_res,
									res);

811
		if (!(gfp_mask & __GFP_WAIT))
812
			goto nomem;
813

814 815
		ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, gfp_mask,
							noswap);
816 817

		/*
818 819 820 821 822
		 * 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
823
		 *
824
		 */
825 826
		if (mem_cgroup_check_under_limit(mem_over_limit))
			continue;
827 828

		if (!nr_retries--) {
829
			if (oom) {
830 831
				mem_cgroup_out_of_memory(mem_over_limit, gfp_mask);
				mem_over_limit->last_oom_jiffies = jiffies;
832
			}
833
			goto nomem;
834
		}
835
	}
836 837 838 839 840
	return 0;
nomem:
	css_put(&mem->css);
	return -ENOMEM;
}
841

842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860
/**
 * mem_cgroup_try_charge - get charge of PAGE_SIZE.
 * @mm: an mm_struct which is charged against. (when *memcg is NULL)
 * @gfp_mask: gfp_mask for reclaim.
 * @memcg: a pointer to memory cgroup which is charged against.
 *
 * charge against memory cgroup pointed by *memcg. if *memcg == NULL, estimated
 * memory cgroup from @mm is got and stored in *memcg.
 *
 * Returns 0 if success. -ENOMEM at failure.
 * This call can invoke OOM-Killer.
 */

int mem_cgroup_try_charge(struct mm_struct *mm,
			  gfp_t mask, struct mem_cgroup **memcg)
{
	return __mem_cgroup_try_charge(mm, mask, memcg, true);
}

861 862 863 864 865 866 867 868 869 870 871 872
/*
 * commit a charge got by mem_cgroup_try_charge() and makes page_cgroup to be
 * USED state. If already USED, uncharge and return.
 */

static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
				     struct page_cgroup *pc,
				     enum charge_type ctype)
{
	/* try_charge() can return NULL to *memcg, taking care of it. */
	if (!mem)
		return;
873 874 875 876 877

	lock_page_cgroup(pc);
	if (unlikely(PageCgroupUsed(pc))) {
		unlock_page_cgroup(pc);
		res_counter_uncharge(&mem->res, PAGE_SIZE);
878 879
		if (do_swap_account)
			res_counter_uncharge(&mem->memsw, PAGE_SIZE);
880
		css_put(&mem->css);
881
		return;
882
	}
883
	pc->mem_cgroup = mem;
K
KAMEZAWA Hiroyuki 已提交
884
	smp_wmb();
885
	pc->flags = pcg_default_flags[ctype];
886

K
KAMEZAWA Hiroyuki 已提交
887
	mem_cgroup_charge_statistics(mem, pc, true);
888 889

	unlock_page_cgroup(pc);
890
}
891

892 893 894 895 896 897 898
/**
 * mem_cgroup_move_account - move account of the page
 * @pc:	page_cgroup of the page.
 * @from: mem_cgroup which the page is moved from.
 * @to:	mem_cgroup which the page is moved to. @from != @to.
 *
 * The caller must confirm following.
K
KAMEZAWA Hiroyuki 已提交
899
 * - page is not on LRU (isolate_page() is useful.)
900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915
 *
 * returns 0 at success,
 * returns -EBUSY when lock is busy or "pc" is unstable.
 *
 * This function does "uncharge" from old cgroup but doesn't do "charge" to
 * new cgroup. It should be done by a caller.
 */

static int mem_cgroup_move_account(struct page_cgroup *pc,
	struct mem_cgroup *from, struct mem_cgroup *to)
{
	struct mem_cgroup_per_zone *from_mz, *to_mz;
	int nid, zid;
	int ret = -EBUSY;

	VM_BUG_ON(from == to);
K
KAMEZAWA Hiroyuki 已提交
916
	VM_BUG_ON(PageLRU(pc->page));
917 918 919 920 921 922 923 924 925 926 927 928 929 930 931

	nid = page_cgroup_nid(pc);
	zid = page_cgroup_zid(pc);
	from_mz =  mem_cgroup_zoneinfo(from, nid, zid);
	to_mz =  mem_cgroup_zoneinfo(to, nid, zid);

	if (!trylock_page_cgroup(pc))
		return ret;

	if (!PageCgroupUsed(pc))
		goto out;

	if (pc->mem_cgroup != from)
		goto out;

K
KAMEZAWA Hiroyuki 已提交
932 933 934 935 936 937 938 939 940
	css_put(&from->css);
	res_counter_uncharge(&from->res, PAGE_SIZE);
	mem_cgroup_charge_statistics(from, pc, false);
	if (do_swap_account)
		res_counter_uncharge(&from->memsw, PAGE_SIZE);
	pc->mem_cgroup = to;
	mem_cgroup_charge_statistics(to, pc, true);
	css_get(&to->css);
	ret = 0;
941 942 943 944 945 946 947 948 949 950 951 952 953
out:
	unlock_page_cgroup(pc);
	return ret;
}

/*
 * move charges to its parent.
 */

static int mem_cgroup_move_parent(struct page_cgroup *pc,
				  struct mem_cgroup *child,
				  gfp_t gfp_mask)
{
K
KAMEZAWA Hiroyuki 已提交
954
	struct page *page = pc->page;
955 956 957 958 959 960 961 962 963
	struct cgroup *cg = child->css.cgroup;
	struct cgroup *pcg = cg->parent;
	struct mem_cgroup *parent;
	int ret;

	/* Is ROOT ? */
	if (!pcg)
		return -EINVAL;

K
KAMEZAWA Hiroyuki 已提交
964

965 966
	parent = mem_cgroup_from_cont(pcg);

K
KAMEZAWA Hiroyuki 已提交
967

968
	ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false);
969
	if (ret || !parent)
970 971
		return ret;

K
KAMEZAWA Hiroyuki 已提交
972 973 974 975 976 977 978
	if (!get_page_unless_zero(page))
		return -EBUSY;

	ret = isolate_lru_page(page);

	if (ret)
		goto cancel;
979 980 981

	ret = mem_cgroup_move_account(pc, child, parent);

K
KAMEZAWA Hiroyuki 已提交
982
	/* drop extra refcnt by try_charge() (move_account increment one) */
983
	css_put(&parent->css);
K
KAMEZAWA Hiroyuki 已提交
984 985 986 987
	putback_lru_page(page);
	if (!ret) {
		put_page(page);
		return 0;
988
	}
K
KAMEZAWA Hiroyuki 已提交
989 990 991 992 993 994
	/* uncharge if move fails */
cancel:
	res_counter_uncharge(&parent->res, PAGE_SIZE);
	if (do_swap_account)
		res_counter_uncharge(&parent->memsw, PAGE_SIZE);
	put_page(page);
995 996 997
	return ret;
}

998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018
/*
 * 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)
{
	struct mem_cgroup *mem;
	struct page_cgroup *pc;
	int ret;

	pc = lookup_page_cgroup(page);
	/* can happen at boot */
	if (unlikely(!pc))
		return 0;
	prefetchw(pc);

	mem = memcg;
1019
	ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true);
1020
	if (ret || !mem)
1021 1022 1023
		return ret;

	__mem_cgroup_commit_charge(mem, pc, ctype);
1024 1025 1026
	return 0;
}

1027 1028
int mem_cgroup_newpage_charge(struct page *page,
			      struct mm_struct *mm, gfp_t gfp_mask)
1029
{
1030
	if (mem_cgroup_disabled())
1031
		return 0;
1032 1033
	if (PageCompound(page))
		return 0;
1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044
	/*
	 * If already mapped, we don't have to account.
	 * If page cache, page->mapping has address_space.
	 * But page->mapping may have out-of-use anon_vma pointer,
	 * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
	 * is NULL.
  	 */
	if (page_mapped(page) || (page->mapping && !PageAnon(page)))
		return 0;
	if (unlikely(!mm))
		mm = &init_mm;
1045
	return mem_cgroup_charge_common(page, mm, gfp_mask,
1046
				MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL);
1047 1048
}

1049 1050
int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
				gfp_t gfp_mask)
1051
{
1052
	if (mem_cgroup_disabled())
1053
		return 0;
1054 1055
	if (PageCompound(page))
		return 0;
1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067
	/*
	 * Corner case handling. This is called from add_to_page_cache()
	 * in usual. But some FS (shmem) precharges this page before calling it
	 * and call add_to_page_cache() with GFP_NOWAIT.
	 *
	 * For GFP_NOWAIT case, the page may be pre-charged before calling
	 * add_to_page_cache(). (See shmem.c) check it here and avoid to call
	 * charge twice. (It works but has to pay a bit larger cost.)
	 */
	if (!(gfp_mask & __GFP_WAIT)) {
		struct page_cgroup *pc;

1068 1069 1070 1071 1072 1073 1074

		pc = lookup_page_cgroup(page);
		if (!pc)
			return 0;
		lock_page_cgroup(pc);
		if (PageCgroupUsed(pc)) {
			unlock_page_cgroup(pc);
1075 1076
			return 0;
		}
1077
		unlock_page_cgroup(pc);
1078 1079
	}

1080
	if (unlikely(!mm))
1081
		mm = &init_mm;
1082

1083 1084
	if (page_is_file_cache(page))
		return mem_cgroup_charge_common(page, mm, gfp_mask,
1085
				MEM_CGROUP_CHARGE_TYPE_CACHE, NULL);
1086 1087 1088
	else
		return mem_cgroup_charge_common(page, mm, gfp_mask,
				MEM_CGROUP_CHARGE_TYPE_SHMEM, NULL);
1089 1090
}

1091 1092 1093 1094 1095 1096 1097
int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
				 struct page *page,
				 gfp_t mask, struct mem_cgroup **ptr)
{
	struct mem_cgroup *mem;
	swp_entry_t     ent;

1098
	if (mem_cgroup_disabled())
1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124
		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: return success
	 * to go on to do_swap_page()'s pte_same() test, which should fail.
	 */
	if (!PageSwapCache(page))
		return 0;

	ent.val = page_private(page);

	mem = lookup_swap_cgroup(ent);
	if (!mem || mem->obsolete)
		goto charge_cur_mm;
	*ptr = mem;
	return __mem_cgroup_try_charge(NULL, mask, ptr, true);
charge_cur_mm:
	if (unlikely(!mm))
		mm = &init_mm;
	return __mem_cgroup_try_charge(mm, mask, ptr, true);
}

K
KAMEZAWA Hiroyuki 已提交
1125
#ifdef CONFIG_SWAP
1126

K
KAMEZAWA Hiroyuki 已提交
1127 1128 1129 1130 1131
int mem_cgroup_cache_charge_swapin(struct page *page,
			struct mm_struct *mm, gfp_t mask, bool locked)
{
	int ret = 0;

1132
	if (mem_cgroup_disabled())
K
KAMEZAWA Hiroyuki 已提交
1133 1134 1135 1136 1137 1138 1139 1140 1141 1142
		return 0;
	if (unlikely(!mm))
		mm = &init_mm;
	if (!locked)
		lock_page(page);
	/*
	 * If not locked, the page can be dropped from SwapCache until
	 * we reach here.
	 */
	if (PageSwapCache(page)) {
1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153
		struct mem_cgroup *mem = NULL;
		swp_entry_t ent;

		ent.val = page_private(page);
		if (do_swap_account) {
			mem = lookup_swap_cgroup(ent);
			if (mem && mem->obsolete)
				mem = NULL;
			if (mem)
				mm = NULL;
		}
K
KAMEZAWA Hiroyuki 已提交
1154
		ret = mem_cgroup_charge_common(page, mm, mask,
1155 1156 1157 1158 1159 1160 1161 1162 1163 1164
				MEM_CGROUP_CHARGE_TYPE_SHMEM, mem);

		if (!ret && do_swap_account) {
			/* avoid double counting */
			mem = swap_cgroup_record(ent, NULL);
			if (mem) {
				res_counter_uncharge(&mem->memsw, PAGE_SIZE);
				mem_cgroup_put(mem);
			}
		}
K
KAMEZAWA Hiroyuki 已提交
1165 1166 1167
	}
	if (!locked)
		unlock_page(page);
K
KAMEZAWA Hiroyuki 已提交
1168 1169
	/* add this page(page_cgroup) to the LRU we want. */
	mem_cgroup_lru_fixup(page);
K
KAMEZAWA Hiroyuki 已提交
1170 1171 1172 1173 1174

	return ret;
}
#endif

1175 1176 1177 1178
void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
{
	struct page_cgroup *pc;

1179
	if (mem_cgroup_disabled())
1180 1181 1182 1183 1184
		return;
	if (!ptr)
		return;
	pc = lookup_page_cgroup(page);
	__mem_cgroup_commit_charge(ptr, pc, MEM_CGROUP_CHARGE_TYPE_MAPPED);
1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201
	/*
	 * 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. This SwapCache is stable
	 * because we're still under lock_page().
	 */
	if (do_swap_account) {
		swp_entry_t ent = {.val = page_private(page)};
		struct mem_cgroup *memcg;
		memcg = swap_cgroup_record(ent, NULL);
		if (memcg) {
			/* If memcg is obsolete, memcg can be != ptr */
			res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
			mem_cgroup_put(memcg);
		}

	}
K
KAMEZAWA Hiroyuki 已提交
1202 1203
	/* add this page(page_cgroup) to the LRU we want. */
	mem_cgroup_lru_fixup(page);
1204 1205 1206 1207
}

void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
{
1208
	if (mem_cgroup_disabled())
1209 1210 1211 1212
		return;
	if (!mem)
		return;
	res_counter_uncharge(&mem->res, PAGE_SIZE);
1213 1214
	if (do_swap_account)
		res_counter_uncharge(&mem->memsw, PAGE_SIZE);
1215 1216 1217 1218
	css_put(&mem->css);
}


1219
/*
1220
 * uncharge if !page_mapped(page)
1221
 */
1222
static struct mem_cgroup *
1223
__mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
1224
{
H
Hugh Dickins 已提交
1225
	struct page_cgroup *pc;
1226
	struct mem_cgroup *mem = NULL;
1227
	struct mem_cgroup_per_zone *mz;
1228

1229
	if (mem_cgroup_disabled())
1230
		return NULL;
1231

K
KAMEZAWA Hiroyuki 已提交
1232
	if (PageSwapCache(page))
1233
		return NULL;
K
KAMEZAWA Hiroyuki 已提交
1234

1235
	/*
1236
	 * Check if our page_cgroup is valid
1237
	 */
1238 1239
	pc = lookup_page_cgroup(page);
	if (unlikely(!pc || !PageCgroupUsed(pc)))
1240
		return NULL;
1241

1242
	lock_page_cgroup(pc);
K
KAMEZAWA Hiroyuki 已提交
1243

1244 1245
	mem = pc->mem_cgroup;

K
KAMEZAWA Hiroyuki 已提交
1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262
	if (!PageCgroupUsed(pc))
		goto unlock_out;

	switch (ctype) {
	case MEM_CGROUP_CHARGE_TYPE_MAPPED:
		if (page_mapped(page))
			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;
1263
	}
K
KAMEZAWA Hiroyuki 已提交
1264

1265 1266 1267 1268
	res_counter_uncharge(&mem->res, PAGE_SIZE);
	if (do_swap_account && (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT))
		res_counter_uncharge(&mem->memsw, PAGE_SIZE);

K
KAMEZAWA Hiroyuki 已提交
1269
	mem_cgroup_charge_statistics(mem, pc, false);
1270
	ClearPageCgroupUsed(pc);
1271

1272
	mz = page_cgroup_zoneinfo(pc);
1273
	unlock_page_cgroup(pc);
H
Hugh Dickins 已提交
1274

K
KAMEZAWA Hiroyuki 已提交
1275 1276 1277
	/* at swapout, this memcg will be accessed to record to swap */
	if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
		css_put(&mem->css);
1278

1279
	return mem;
K
KAMEZAWA Hiroyuki 已提交
1280 1281 1282

unlock_out:
	unlock_page_cgroup(pc);
1283
	return NULL;
1284 1285
}

1286 1287
void mem_cgroup_uncharge_page(struct page *page)
{
1288 1289 1290 1291 1292
	/* early check. */
	if (page_mapped(page))
		return;
	if (page->mapping && !PageAnon(page))
		return;
1293 1294 1295 1296 1297 1298
	__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));
1299
	VM_BUG_ON(page->mapping);
1300 1301 1302
	__mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
}

1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317
/*
 * called from __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)
{
	struct mem_cgroup *memcg;

	memcg = __mem_cgroup_uncharge_common(page,
					MEM_CGROUP_CHARGE_TYPE_SWAPOUT);
	/* record memcg information */
	if (do_swap_account && memcg) {
		swap_cgroup_record(ent, memcg);
		mem_cgroup_get(memcg);
	}
K
KAMEZAWA Hiroyuki 已提交
1318 1319
	if (memcg)
		css_put(&memcg->css);
1320 1321 1322 1323 1324 1325 1326 1327
}

#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)
K
KAMEZAWA Hiroyuki 已提交
1328
{
1329 1330 1331 1332 1333 1334 1335 1336 1337 1338
	struct mem_cgroup *memcg;

	if (!do_swap_account)
		return;

	memcg = swap_cgroup_record(ent, NULL);
	if (memcg) {
		res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
		mem_cgroup_put(memcg);
	}
K
KAMEZAWA Hiroyuki 已提交
1339
}
1340
#endif
K
KAMEZAWA Hiroyuki 已提交
1341

1342
/*
1343 1344
 * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
 * page belongs to.
1345
 */
1346
int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
1347 1348
{
	struct page_cgroup *pc;
1349 1350
	struct mem_cgroup *mem = NULL;
	int ret = 0;
1351

1352
	if (mem_cgroup_disabled())
1353 1354
		return 0;

1355 1356 1357
	pc = lookup_page_cgroup(page);
	lock_page_cgroup(pc);
	if (PageCgroupUsed(pc)) {
1358 1359 1360
		mem = pc->mem_cgroup;
		css_get(&mem->css);
	}
1361
	unlock_page_cgroup(pc);
1362

1363
	if (mem) {
K
KAMEZAWA Hiroyuki 已提交
1364
		ret = mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem);
1365 1366
		css_put(&mem->css);
	}
1367
	*ptr = mem;
1368
	return ret;
1369
}
1370

1371
/* remove redundant charge if migration failed*/
1372 1373
void mem_cgroup_end_migration(struct mem_cgroup *mem,
		struct page *oldpage, struct page *newpage)
1374
{
1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398
	struct page *target, *unused;
	struct page_cgroup *pc;
	enum charge_type ctype;

	if (!mem)
		return;

	/* at migration success, oldpage->mapping is NULL. */
	if (oldpage->mapping) {
		target = oldpage;
		unused = NULL;
	} else {
		target = newpage;
		unused = oldpage;
	}

	if (PageAnon(target))
		ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
	else if (page_is_file_cache(target))
		ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
	else
		ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;

	/* unused page is not on radix-tree now. */
K
KAMEZAWA Hiroyuki 已提交
1399
	if (unused)
1400 1401 1402
		__mem_cgroup_uncharge_common(unused, ctype);

	pc = lookup_page_cgroup(target);
1403
	/*
1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417
	 * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup.
	 * So, double-counting is effectively avoided.
	 */
	__mem_cgroup_commit_charge(mem, pc, ctype);

	/*
	 * Both of oldpage and newpage are still under lock_page().
	 * Then, we don't have to care about race in radix-tree.
	 * But we have to be careful that this page is unmapped or not.
	 *
	 * There is a case for !page_mapped(). At the start of
	 * migration, oldpage was mapped. But now, it's zapped.
	 * But we know *target* page is not freed/reused under us.
	 * mem_cgroup_uncharge_page() does all necessary checks.
1418
	 */
1419 1420
	if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
		mem_cgroup_uncharge_page(target);
1421
}
1422

1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433
/*
 * A call to try to shrink memory usage under specified resource controller.
 * This is typically used for page reclaiming for shmem for reducing side
 * effect of page allocation from shmem, which is used by some mem_cgroup.
 */
int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
{
	struct mem_cgroup *mem;
	int progress = 0;
	int retry = MEM_CGROUP_RECLAIM_RETRIES;

1434
	if (mem_cgroup_disabled())
1435
		return 0;
1436 1437
	if (!mm)
		return 0;
1438

1439 1440
	rcu_read_lock();
	mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
1441 1442 1443 1444
	if (unlikely(!mem)) {
		rcu_read_unlock();
		return 0;
	}
1445 1446 1447 1448
	css_get(&mem->css);
	rcu_read_unlock();

	do {
K
KOSAKI Motohiro 已提交
1449 1450
		progress = try_to_free_mem_cgroup_pages(mem, gfp_mask, true,
							get_swappiness(mem));
1451
		progress += mem_cgroup_check_under_limit(mem);
1452 1453 1454 1455 1456 1457 1458 1459
	} while (!progress && --retry);

	css_put(&mem->css);
	if (!retry)
		return -ENOMEM;
	return 0;
}

1460 1461
static DEFINE_MUTEX(set_limit_mutex);

1462
static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
1463
				unsigned long long val)
1464 1465 1466 1467
{

	int retry_count = MEM_CGROUP_RECLAIM_RETRIES;
	int progress;
1468
	u64 memswlimit;
1469 1470
	int ret = 0;

1471
	while (retry_count) {
1472 1473 1474 1475
		if (signal_pending(current)) {
			ret = -EINTR;
			break;
		}
1476 1477 1478 1479 1480 1481 1482 1483 1484 1485
		/*
		 * Rather than hide all in some function, I do this in
		 * open coded manner. You see what this really does.
		 * We have to guarantee mem->res.limit < mem->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);
1486 1487
			break;
		}
1488 1489 1490 1491 1492 1493
		ret = res_counter_set_limit(&memcg->res, val);
		mutex_unlock(&set_limit_mutex);

		if (!ret)
			break;

1494
		progress = try_to_free_mem_cgroup_pages(memcg,
K
KOSAKI Motohiro 已提交
1495 1496 1497
							GFP_KERNEL,
							false,
							get_swappiness(memcg));
1498 1499
  		if (!progress)			retry_count--;
	}
1500

1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537
	return ret;
}

int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
				unsigned long long val)
{
	int retry_count = MEM_CGROUP_RECLAIM_RETRIES;
	u64 memlimit, oldusage, curusage;
	int ret;

	if (!do_swap_account)
		return -EINVAL;

	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 mem->res.limit < mem->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;
		}
		ret = res_counter_set_limit(&memcg->memsw, val);
		mutex_unlock(&set_limit_mutex);

		if (!ret)
			break;

		oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
K
KOSAKI Motohiro 已提交
1538 1539
		try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL, true,
					     get_swappiness(memcg));
1540 1541
		curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
		if (curusage >= oldusage)
1542 1543 1544 1545 1546
			retry_count--;
	}
	return ret;
}

1547 1548 1549 1550
/*
 * This routine traverse page_cgroup in given list and drop them all.
 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
 */
1551
static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
K
KAMEZAWA Hiroyuki 已提交
1552
				int node, int zid, enum lru_list lru)
1553
{
K
KAMEZAWA Hiroyuki 已提交
1554 1555
	struct zone *zone;
	struct mem_cgroup_per_zone *mz;
1556
	struct page_cgroup *pc, *busy;
K
KAMEZAWA Hiroyuki 已提交
1557
	unsigned long flags, loop;
1558
	struct list_head *list;
1559
	int ret = 0;
1560

K
KAMEZAWA Hiroyuki 已提交
1561 1562
	zone = &NODE_DATA(node)->node_zones[zid];
	mz = mem_cgroup_zoneinfo(mem, node, zid);
1563
	list = &mz->lists[lru];
1564

1565 1566 1567 1568 1569 1570
	loop = MEM_CGROUP_ZSTAT(mz, lru);
	/* give some margin against EBUSY etc...*/
	loop += 256;
	busy = NULL;
	while (loop--) {
		ret = 0;
K
KAMEZAWA Hiroyuki 已提交
1571
		spin_lock_irqsave(&zone->lru_lock, flags);
1572
		if (list_empty(list)) {
K
KAMEZAWA Hiroyuki 已提交
1573
			spin_unlock_irqrestore(&zone->lru_lock, flags);
1574
			break;
1575 1576 1577 1578 1579
		}
		pc = list_entry(list->prev, struct page_cgroup, lru);
		if (busy == pc) {
			list_move(&pc->lru, list);
			busy = 0;
K
KAMEZAWA Hiroyuki 已提交
1580
			spin_unlock_irqrestore(&zone->lru_lock, flags);
1581 1582
			continue;
		}
K
KAMEZAWA Hiroyuki 已提交
1583
		spin_unlock_irqrestore(&zone->lru_lock, flags);
1584

K
KAMEZAWA Hiroyuki 已提交
1585
		ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL);
1586
		if (ret == -ENOMEM)
1587
			break;
1588 1589 1590 1591 1592 1593 1594

		if (ret == -EBUSY || ret == -EINVAL) {
			/* found lock contention or "pc" is obsolete. */
			busy = pc;
			cond_resched();
		} else
			busy = NULL;
1595
	}
K
KAMEZAWA Hiroyuki 已提交
1596

1597 1598 1599
	if (!ret && !list_empty(list))
		return -EBUSY;
	return ret;
1600 1601 1602 1603 1604 1605
}

/*
 * make mem_cgroup's charge to be 0 if there is no task.
 * This enables deleting this mem_cgroup.
 */
1606
static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
1607
{
1608 1609 1610
	int ret;
	int node, zid, shrink;
	int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
1611
	struct cgroup *cgrp = mem->css.cgroup;
1612

1613
	css_get(&mem->css);
1614 1615

	shrink = 0;
1616 1617 1618
	/* should free all ? */
	if (free_all)
		goto try_to_free;
1619
move_account:
1620
	while (mem->res.usage > 0) {
1621
		ret = -EBUSY;
1622 1623 1624 1625
		if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
			goto out;
		ret = -EINTR;
		if (signal_pending(current))
1626
			goto out;
1627 1628
		/* This is for making all *used* pages to be on LRU. */
		lru_add_drain_all();
1629 1630 1631
		ret = 0;
		for_each_node_state(node, N_POSSIBLE) {
			for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) {
1632
				enum lru_list l;
1633 1634
				for_each_lru(l) {
					ret = mem_cgroup_force_empty_list(mem,
K
KAMEZAWA Hiroyuki 已提交
1635
							node, zid, l);
1636 1637 1638
					if (ret)
						break;
				}
1639
			}
1640 1641 1642 1643 1644 1645
			if (ret)
				break;
		}
		/* it seems parent cgroup doesn't have enough mem */
		if (ret == -ENOMEM)
			goto try_to_free;
1646
		cond_resched();
1647 1648 1649 1650 1651
	}
	ret = 0;
out:
	css_put(&mem->css);
	return ret;
1652 1653

try_to_free:
1654 1655
	/* returns EBUSY if there is a task or if we come here twice. */
	if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) {
1656 1657 1658
		ret = -EBUSY;
		goto out;
	}
1659 1660
	/* we call try-to-free pages for make this cgroup empty */
	lru_add_drain_all();
1661 1662 1663 1664
	/* try to free all pages in this cgroup */
	shrink = 1;
	while (nr_retries && mem->res.usage > 0) {
		int progress;
1665 1666 1667 1668 1669

		if (signal_pending(current)) {
			ret = -EINTR;
			goto out;
		}
K
KOSAKI Motohiro 已提交
1670 1671
		progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
						false, get_swappiness(mem));
1672
		if (!progress) {
1673
			nr_retries--;
1674 1675 1676
			/* maybe some writeback is necessary */
			congestion_wait(WRITE, HZ/10);
		}
1677 1678

	}
K
KAMEZAWA Hiroyuki 已提交
1679
	lru_add_drain();
1680 1681 1682 1683 1684
	/* try move_account...there may be some *locked* pages. */
	if (mem->res.usage)
		goto move_account;
	ret = 0;
	goto out;
1685 1686
}

1687 1688 1689 1690 1691 1692
int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event)
{
	return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true);
}


1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730
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 *mem = mem_cgroup_from_cont(cont);
	struct cgroup *parent = cont->parent;
	struct mem_cgroup *parent_mem = NULL;

	if (parent)
		parent_mem = mem_cgroup_from_cont(parent);

	cgroup_lock();
	/*
	 * If parent's use_hiearchy 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_mem || !parent_mem->use_hierarchy) &&
				(val == 1 || val == 0)) {
		if (list_empty(&cont->children))
			mem->use_hierarchy = val;
		else
			retval = -EBUSY;
	} else
		retval = -EINVAL;
	cgroup_unlock();

	return retval;
}

1731
static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
B
Balbir Singh 已提交
1732
{
1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751
	struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
	u64 val = 0;
	int type, name;

	type = MEMFILE_TYPE(cft->private);
	name = MEMFILE_ATTR(cft->private);
	switch (type) {
	case _MEM:
		val = res_counter_read_u64(&mem->res, name);
		break;
	case _MEMSWAP:
		if (do_swap_account)
			val = res_counter_read_u64(&mem->memsw, name);
		break;
	default:
		BUG();
		break;
	}
	return val;
B
Balbir Singh 已提交
1752
}
1753 1754 1755 1756
/*
 * The user of this function is...
 * RES_LIMIT.
 */
1757 1758
static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
			    const char *buffer)
B
Balbir Singh 已提交
1759
{
1760
	struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
1761
	int type, name;
1762 1763 1764
	unsigned long long val;
	int ret;

1765 1766 1767
	type = MEMFILE_TYPE(cft->private);
	name = MEMFILE_ATTR(cft->private);
	switch (name) {
1768 1769 1770
	case RES_LIMIT:
		/* This function does all necessary parse...reuse it */
		ret = res_counter_memparse_write_strategy(buffer, &val);
1771 1772 1773
		if (ret)
			break;
		if (type == _MEM)
1774
			ret = mem_cgroup_resize_limit(memcg, val);
1775 1776
		else
			ret = mem_cgroup_resize_memsw_limit(memcg, val);
1777 1778 1779 1780 1781 1782
		break;
	default:
		ret = -EINVAL; /* should be BUG() ? */
		break;
	}
	return ret;
B
Balbir Singh 已提交
1783 1784
}

1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812
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;
}

1813
static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
1814 1815
{
	struct mem_cgroup *mem;
1816
	int type, name;
1817 1818

	mem = mem_cgroup_from_cont(cont);
1819 1820 1821
	type = MEMFILE_TYPE(event);
	name = MEMFILE_ATTR(event);
	switch (name) {
1822
	case RES_MAX_USAGE:
1823 1824 1825 1826
		if (type == _MEM)
			res_counter_reset_max(&mem->res);
		else
			res_counter_reset_max(&mem->memsw);
1827 1828
		break;
	case RES_FAILCNT:
1829 1830 1831 1832
		if (type == _MEM)
			res_counter_reset_failcnt(&mem->res);
		else
			res_counter_reset_failcnt(&mem->memsw);
1833 1834
		break;
	}
1835
	return 0;
1836 1837
}

1838 1839 1840 1841 1842 1843
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, },
1844 1845
	[MEM_CGROUP_STAT_PGPGIN_COUNT] = {"pgpgin", 1, },
	[MEM_CGROUP_STAT_PGPGOUT_COUNT] = {"pgpgout", 1, },
1846 1847
};

1848 1849
static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
				 struct cgroup_map_cb *cb)
1850 1851 1852 1853 1854 1855 1856 1857 1858 1859
{
	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;
1860
		cb->fill(cb, mem_cgroup_stat_desc[i].msg, val);
1861
	}
1862 1863
	/* showing # of active pages */
	{
1864 1865
		unsigned long active_anon, inactive_anon;
		unsigned long active_file, inactive_file;
L
Lee Schermerhorn 已提交
1866
		unsigned long unevictable;
1867 1868 1869 1870 1871 1872 1873 1874 1875

		inactive_anon = mem_cgroup_get_all_zonestat(mem_cont,
						LRU_INACTIVE_ANON);
		active_anon = mem_cgroup_get_all_zonestat(mem_cont,
						LRU_ACTIVE_ANON);
		inactive_file = mem_cgroup_get_all_zonestat(mem_cont,
						LRU_INACTIVE_FILE);
		active_file = mem_cgroup_get_all_zonestat(mem_cont,
						LRU_ACTIVE_FILE);
L
Lee Schermerhorn 已提交
1876 1877 1878
		unevictable = mem_cgroup_get_all_zonestat(mem_cont,
							LRU_UNEVICTABLE);

1879 1880 1881 1882
		cb->fill(cb, "active_anon", (active_anon) * PAGE_SIZE);
		cb->fill(cb, "inactive_anon", (inactive_anon) * PAGE_SIZE);
		cb->fill(cb, "active_file", (active_file) * PAGE_SIZE);
		cb->fill(cb, "inactive_file", (inactive_file) * PAGE_SIZE);
L
Lee Schermerhorn 已提交
1883 1884
		cb->fill(cb, "unevictable", unevictable * PAGE_SIZE);

1885
	}
1886 1887 1888 1889 1890 1891 1892
	{
		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);
	}
K
KOSAKI Motohiro 已提交
1893 1894

#ifdef CONFIG_DEBUG_VM
1895
	cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));
K
KOSAKI Motohiro 已提交
1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922

	{
		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

1923 1924 1925
	return 0;
}

K
KOSAKI Motohiro 已提交
1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956
static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
{
	struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);

	return get_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);
	/* If under hierarchy, only empty-root can set this value */
	if ((parent->use_hierarchy) ||
	    (memcg->use_hierarchy && !list_empty(&cgrp->children)))
		return -EINVAL;

	spin_lock(&memcg->reclaim_param_lock);
	memcg->swappiness = val;
	spin_unlock(&memcg->reclaim_param_lock);

	return 0;
}

1957

B
Balbir Singh 已提交
1958 1959
static struct cftype mem_cgroup_files[] = {
	{
1960
		.name = "usage_in_bytes",
1961
		.private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
1962
		.read_u64 = mem_cgroup_read,
B
Balbir Singh 已提交
1963
	},
1964 1965
	{
		.name = "max_usage_in_bytes",
1966
		.private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
1967
		.trigger = mem_cgroup_reset,
1968 1969
		.read_u64 = mem_cgroup_read,
	},
B
Balbir Singh 已提交
1970
	{
1971
		.name = "limit_in_bytes",
1972
		.private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
1973
		.write_string = mem_cgroup_write,
1974
		.read_u64 = mem_cgroup_read,
B
Balbir Singh 已提交
1975 1976 1977
	},
	{
		.name = "failcnt",
1978
		.private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
1979
		.trigger = mem_cgroup_reset,
1980
		.read_u64 = mem_cgroup_read,
B
Balbir Singh 已提交
1981
	},
1982 1983
	{
		.name = "stat",
1984
		.read_map = mem_control_stat_show,
1985
	},
1986 1987 1988 1989
	{
		.name = "force_empty",
		.trigger = mem_cgroup_force_empty_write,
	},
1990 1991 1992 1993 1994
	{
		.name = "use_hierarchy",
		.write_u64 = mem_cgroup_hierarchy_write,
		.read_u64 = mem_cgroup_hierarchy_read,
	},
K
KOSAKI Motohiro 已提交
1995 1996 1997 1998 1999
	{
		.name = "swappiness",
		.read_u64 = mem_cgroup_swappiness_read,
		.write_u64 = mem_cgroup_swappiness_write,
	},
B
Balbir Singh 已提交
2000 2001
};

2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042
#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,
	},
	{
		.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

2043 2044 2045
static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
{
	struct mem_cgroup_per_node *pn;
2046
	struct mem_cgroup_per_zone *mz;
2047
	enum lru_list l;
2048
	int zone, tmp = node;
2049 2050 2051 2052 2053 2054 2055 2056
	/*
	 * 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.
	 */
2057 2058 2059
	if (!node_state(node, N_NORMAL_MEMORY))
		tmp = -1;
	pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
2060 2061
	if (!pn)
		return 1;
2062

2063 2064
	mem->info.nodeinfo[node] = pn;
	memset(pn, 0, sizeof(*pn));
2065 2066 2067

	for (zone = 0; zone < MAX_NR_ZONES; zone++) {
		mz = &pn->zoneinfo[zone];
2068 2069
		for_each_lru(l)
			INIT_LIST_HEAD(&mz->lists[l]);
2070
	}
2071 2072 2073
	return 0;
}

2074 2075 2076 2077 2078
static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
{
	kfree(mem->info.nodeinfo[node]);
}

2079 2080 2081 2082 2083 2084
static int mem_cgroup_size(void)
{
	int cpustat_size = nr_cpu_ids * sizeof(struct mem_cgroup_stat_cpu);
	return sizeof(struct mem_cgroup) + cpustat_size;
}

2085 2086 2087
static struct mem_cgroup *mem_cgroup_alloc(void)
{
	struct mem_cgroup *mem;
2088
	int size = mem_cgroup_size();
2089

2090 2091
	if (size < PAGE_SIZE)
		mem = kmalloc(size, GFP_KERNEL);
2092
	else
2093
		mem = vmalloc(size);
2094 2095

	if (mem)
2096
		memset(mem, 0, size);
2097 2098 2099
	return mem;
}

2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113
/*
 * 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.
 *
 * When mem_cgroup is destroyed, mem->obsolete will be set to 0 and
 * entry which points to this memcg will be ignore at swapin.
 *
 * Removal of cgroup itself succeeds regardless of refs from swap.
 */

2114 2115
static void mem_cgroup_free(struct mem_cgroup *mem)
{
K
KAMEZAWA Hiroyuki 已提交
2116 2117
	int node;

2118 2119
	if (atomic_read(&mem->refcnt) > 0)
		return;
K
KAMEZAWA Hiroyuki 已提交
2120 2121 2122 2123 2124


	for_each_node_state(node, N_POSSIBLE)
		free_mem_cgroup_per_zone_info(mem, node);

2125
	if (mem_cgroup_size() < PAGE_SIZE)
2126 2127 2128 2129 2130
		kfree(mem);
	else
		vfree(mem);
}

2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144
static void mem_cgroup_get(struct mem_cgroup *mem)
{
	atomic_inc(&mem->refcnt);
}

static void mem_cgroup_put(struct mem_cgroup *mem)
{
	if (atomic_dec_and_test(&mem->refcnt)) {
		if (!mem->obsolete)
			return;
		mem_cgroup_free(mem);
	}
}

2145

2146 2147 2148
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
static void __init enable_swap_cgroup(void)
{
2149
	if (!mem_cgroup_disabled() && really_do_swap_account)
2150 2151 2152 2153 2154 2155 2156 2157
		do_swap_account = 1;
}
#else
static void __init enable_swap_cgroup(void)
{
}
#endif

B
Balbir Singh 已提交
2158 2159 2160
static struct cgroup_subsys_state *
mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
{
2161
	struct mem_cgroup *mem, *parent;
2162
	int node;
B
Balbir Singh 已提交
2163

2164 2165 2166
	mem = mem_cgroup_alloc();
	if (!mem)
		return ERR_PTR(-ENOMEM);
2167

2168 2169 2170
	for_each_node_state(node, N_POSSIBLE)
		if (alloc_mem_cgroup_per_zone_info(mem, node))
			goto free_out;
2171
	/* root ? */
2172
	if (cont->parent == NULL) {
2173
		enable_swap_cgroup();
2174
		parent = NULL;
2175
	} else {
2176
		parent = mem_cgroup_from_cont(cont->parent);
2177 2178
		mem->use_hierarchy = parent->use_hierarchy;
	}
2179

2180 2181 2182 2183 2184 2185 2186
	if (parent && parent->use_hierarchy) {
		res_counter_init(&mem->res, &parent->res);
		res_counter_init(&mem->memsw, &parent->memsw);
	} else {
		res_counter_init(&mem->res, NULL);
		res_counter_init(&mem->memsw, NULL);
	}
2187
	mem->last_scanned_child = NULL;
K
KOSAKI Motohiro 已提交
2188
	spin_lock_init(&mem->reclaim_param_lock);
2189

K
KOSAKI Motohiro 已提交
2190 2191 2192
	if (parent)
		mem->swappiness = get_swappiness(parent);

B
Balbir Singh 已提交
2193
	return &mem->css;
2194 2195
free_out:
	for_each_node_state(node, N_POSSIBLE)
2196
		free_mem_cgroup_per_zone_info(mem, node);
2197
	mem_cgroup_free(mem);
2198
	return ERR_PTR(-ENOMEM);
B
Balbir Singh 已提交
2199 2200
}

2201 2202 2203 2204
static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
					struct cgroup *cont)
{
	struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
2205
	mem->obsolete = 1;
2206
	mem_cgroup_force_empty(mem, false);
2207 2208
}

B
Balbir Singh 已提交
2209 2210 2211
static void mem_cgroup_destroy(struct cgroup_subsys *ss,
				struct cgroup *cont)
{
2212
	mem_cgroup_free(mem_cgroup_from_cont(cont));
B
Balbir Singh 已提交
2213 2214 2215 2216 2217
}

static int mem_cgroup_populate(struct cgroup_subsys *ss,
				struct cgroup *cont)
{
2218 2219 2220 2221 2222 2223 2224 2225
	int ret;

	ret = cgroup_add_files(cont, ss, mem_cgroup_files,
				ARRAY_SIZE(mem_cgroup_files));

	if (!ret)
		ret = register_memsw_files(cont, ss);
	return ret;
B
Balbir Singh 已提交
2226 2227
}

B
Balbir Singh 已提交
2228 2229 2230 2231 2232 2233
static void mem_cgroup_move_task(struct cgroup_subsys *ss,
				struct cgroup *cont,
				struct cgroup *old_cont,
				struct task_struct *p)
{
	/*
2234 2235
	 * FIXME: It's better to move charges of this process from old
	 * memcg to new memcg. But it's just on TODO-List now.
B
Balbir Singh 已提交
2236 2237 2238
	 */
}

B
Balbir Singh 已提交
2239 2240 2241 2242
struct cgroup_subsys mem_cgroup_subsys = {
	.name = "memory",
	.subsys_id = mem_cgroup_subsys_id,
	.create = mem_cgroup_create,
2243
	.pre_destroy = mem_cgroup_pre_destroy,
B
Balbir Singh 已提交
2244 2245
	.destroy = mem_cgroup_destroy,
	.populate = mem_cgroup_populate,
B
Balbir Singh 已提交
2246
	.attach = mem_cgroup_move_task,
2247
	.early_init = 0,
B
Balbir Singh 已提交
2248
};
2249 2250 2251 2252 2253 2254 2255 2256 2257 2258

#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP

static int __init disable_swap_account(char *s)
{
	really_do_swap_account = 0;
	return 1;
}
__setup("noswapaccount", disable_swap_account);
#endif