/* memcontrol.c - Memory Controller
*
* Copyright IBM Corporation, 2007
* Author Balbir Singh <balbir@linux.vnet.ibm.com>
*
* Copyright 2007 OpenVZ SWsoft Inc
* Author: Pavel Emelianov <xemul@openvz.org>
*
* 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>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/page-flags.h>
#include <linux/backing-dev.h>
#include <linux/bit_spinlock.h>
#include <linux/rcupdate.h>
#include <linux/slab.h>
#include <linux/swap.h>
#include <linux/spinlock.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/vmalloc.h>
#include <linux/mm_inline.h>
#include <linux/page_cgroup.h>
#include <asm/uaccess.h>
struct cgroup_subsys mem_cgroup_subsys __read_mostly;
#define MEM_CGROUP_RECLAIM_RETRIES 5
/*
* 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 */
MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */
MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */
MEM_CGROUP_STAT_NSTATS,
};
struct mem_cgroup_stat_cpu {
s64 count[MEM_CGROUP_STAT_NSTATS];
} ____cacheline_aligned_in_smp;
struct mem_cgroup_stat {
struct mem_cgroup_stat_cpu cpustat[NR_CPUS];
};
/*
* For accounting under irq disable, no need for increment preempt count.
*/
static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu *stat,
enum mem_cgroup_stat_index idx, int val)
{
stat->count[idx] += val;
}
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;
}
/*
* per-zone information in memory controller.
*/
struct mem_cgroup_per_zone {
/*
* spin_lock to protect the per cgroup LRU
*/
spinlock_t lru_lock;
struct list_head lists[NR_LRU_LISTS];
unsigned long count[NR_LRU_LISTS];
};
/* 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];
};
/*
* 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
* 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.
*/
struct mem_cgroup {
struct cgroup_subsys_state css;
/*
* the counter to account for memory usage
*/
struct res_counter res;
/*
* Per cgroup active and inactive list, similar to the
* per zone LRU lists.
*/
struct mem_cgroup_lru_info info;
int prev_priority; /* for recording reclaim priority */
/*
* statistics.
*/
struct mem_cgroup_stat stat;
};
static struct mem_cgroup init_mem_cgroup;
enum charge_type {
MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
MEM_CGROUP_CHARGE_TYPE_MAPPED,
MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */
MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */
NR_CHARGE_TYPE,
};
/* only for here (for easy reading.) */
#define PCGF_CACHE (1UL << PCG_CACHE)
#define PCGF_USED (1UL << PCG_USED)
#define PCGF_ACTIVE (1UL << PCG_ACTIVE)
#define PCGF_LOCK (1UL << PCG_LOCK)
#define PCGF_FILE (1UL << PCG_FILE)
static const unsigned long
pcg_default_flags[NR_CHARGE_TYPE] = {
PCGF_CACHE | PCGF_FILE | PCGF_USED | PCGF_LOCK, /* File Cache */
PCGF_ACTIVE | PCGF_USED | PCGF_LOCK, /* Anon */
PCGF_ACTIVE | PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */
0, /* FORCE */
};
/*
* Always modified under lru lock. Then, not necessary to preempt_disable()
*/
static void mem_cgroup_charge_statistics(struct mem_cgroup *