--- /dev/null
+/* 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>
+ *
+ * Memory thresholds
+ * Copyright (C) 2009 Nokia Corporation
+ * Author: Kirill A. Shutemov
+ *
+ * Kernel Memory Controller
+ * Copyright (C) 2012 Parallels Inc. and Google Inc.
+ * Authors: Glauber Costa and Suleiman Souhlal
+ *
+ * Native page reclaim
+ * Charge lifetime sanitation
+ * Lockless page tracking & accounting
+ * Unified hierarchy configuration model
+ * Copyright (C) 2015 Red Hat, Inc., Johannes Weiner
+ *
+ * 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/page_counter.h>
+#include <linux/memcontrol.h>
+#include <linux/cgroup.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/pagemap.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/limits.h>
+#include <linux/export.h>
+#include <linux/mutex.h>
+#include <linux/rbtree.h>
+#include <linux/slab.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/spinlock.h>
+#include <linux/eventfd.h>
+#include <linux/poll.h>
+#include <linux/sort.h>
+#include <linux/fs.h>
+#include <linux/seq_file.h>
+#include <linux/vmpressure.h>
+#include <linux/mm_inline.h>
+#include <linux/swap_cgroup.h>
+#include <linux/cpu.h>
+#include <linux/oom.h>
+#include <linux/lockdep.h>
+#include <linux/file.h>
+#include "internal.h"
+#include <net/sock.h>
+#include <net/ip.h>
+#include <net/tcp_memcontrol.h>
+#include <linux/locallock.h>
+
+#include "slab.h"
+
+#include <asm/uaccess.h>
+
+#include <trace/events/vmscan.h>
+
+struct cgroup_subsys memory_cgrp_subsys __read_mostly;
+EXPORT_SYMBOL(memory_cgrp_subsys);
+
+#define MEM_CGROUP_RECLAIM_RETRIES 5
+static struct mem_cgroup *root_mem_cgroup __read_mostly;
+
+/* Whether the swap controller is active */
+#ifdef CONFIG_MEMCG_SWAP
+int do_swap_account __read_mostly;
+#else
+#define do_swap_account 0
+#endif
+
+static DEFINE_LOCAL_IRQ_LOCK(event_lock);
+static const char * const mem_cgroup_stat_names[] = {
+ "cache",
+ "rss",
+ "rss_huge",
+ "mapped_file",
+ "writeback",
+ "swap",
+};
+
+static const char * const mem_cgroup_events_names[] = {
+ "pgpgin",
+ "pgpgout",
+ "pgfault",
+ "pgmajfault",
+};
+
+static const char * const mem_cgroup_lru_names[] = {
+ "inactive_anon",
+ "active_anon",
+ "inactive_file",
+ "active_file",
+ "unevictable",
+};
+
+/*
+ * Per memcg event counter is incremented at every pagein/pageout. With THP,
+ * it will be incremated by the number of pages. This counter is used for
+ * for trigger some periodic events. This is straightforward and better
+ * than using jiffies etc. to handle periodic memcg event.
+ */
+enum mem_cgroup_events_target {
+ MEM_CGROUP_TARGET_THRESH,
+ MEM_CGROUP_TARGET_SOFTLIMIT,
+ MEM_CGROUP_TARGET_NUMAINFO,
+ MEM_CGROUP_NTARGETS,
+};
+#define THRESHOLDS_EVENTS_TARGET 128
+#define SOFTLIMIT_EVENTS_TARGET 1024
+#define NUMAINFO_EVENTS_TARGET 1024
+
+struct mem_cgroup_stat_cpu {
+ long count[MEM_CGROUP_STAT_NSTATS];
+ unsigned long events[MEMCG_NR_EVENTS];
+ unsigned long nr_page_events;
+ unsigned long targets[MEM_CGROUP_NTARGETS];
+};
+
+struct reclaim_iter {
+ struct mem_cgroup *position;
+ /* scan generation, increased every round-trip */
+ unsigned int generation;
+};
+
+/*
+ * per-zone information in memory controller.
+ */
+struct mem_cgroup_per_zone {
+ struct lruvec lruvec;
+ unsigned long lru_size[NR_LRU_LISTS];
+
+ struct reclaim_iter iter[DEF_PRIORITY + 1];
+
+ struct rb_node tree_node; /* RB tree node */
+ unsigned long usage_in_excess;/* Set to the value by which */
+ /* the soft limit is exceeded*/
+ bool on_tree;
+ struct mem_cgroup *memcg; /* Back pointer, we cannot */
+ /* use container_of */
+};
+
+struct mem_cgroup_per_node {
+ struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
+};
+
+/*
+ * Cgroups above their limits are maintained in a RB-Tree, independent of
+ * their hierarchy representation
+ */
+
+struct mem_cgroup_tree_per_zone {
+ struct rb_root rb_root;
+ spinlock_t lock;
+};
+
+struct mem_cgroup_tree_per_node {
+ struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES];
+};
+
+struct mem_cgroup_tree {
+ struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
+};
+
+static struct mem_cgroup_tree soft_limit_tree __read_mostly;
+
+struct mem_cgroup_threshold {
+ struct eventfd_ctx *eventfd;
+ unsigned long threshold;
+};
+
+/* For threshold */
+struct mem_cgroup_threshold_ary {
+ /* An array index points to threshold just below or equal to usage. */
+ int current_threshold;
+ /* Size of entries[] */
+ unsigned int size;
+ /* Array of thresholds */
+ struct mem_cgroup_threshold entries[0];
+};
+
+struct mem_cgroup_thresholds {
+ /* Primary thresholds array */
+ struct mem_cgroup_threshold_ary *primary;
+ /*
+ * Spare threshold array.
+ * This is needed to make mem_cgroup_unregister_event() "never fail".
+ * It must be able to store at least primary->size - 1 entries.
+ */
+ struct mem_cgroup_threshold_ary *spare;
+};
+
+/* for OOM */
+struct mem_cgroup_eventfd_list {
+ struct list_head list;
+ struct eventfd_ctx *eventfd;
+};
+
+/*
+ * cgroup_event represents events which userspace want to receive.
+ */
+struct mem_cgroup_event {
+ /*
+ * memcg which the event belongs to.
+ */
+ struct mem_cgroup *memcg;
+ /*
+ * eventfd to signal userspace about the event.
+ */
+ struct eventfd_ctx *eventfd;
+ /*
+ * Each of these stored in a list by the cgroup.
+ */
+ struct list_head list;
+ /*
+ * register_event() callback will be used to add new userspace
+ * waiter for changes related to this event. Use eventfd_signal()
+ * on eventfd to send notification to userspace.
+ */
+ int (*register_event)(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, const char *args);
+ /*
+ * unregister_event() callback will be called when userspace closes
+ * the eventfd or on cgroup removing. This callback must be set,
+ * if you want provide notification functionality.
+ */
+ void (*unregister_event)(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd);
+ /*
+ * All fields below needed to unregister event when
+ * userspace closes eventfd.
+ */
+ poll_table pt;
+ wait_queue_head_t *wqh;
+ wait_queue_t wait;
+ struct work_struct remove;
+};
+
+static void mem_cgroup_threshold(struct mem_cgroup *memcg);
+static void mem_cgroup_oom_notify(struct mem_cgroup *memcg);
+
+/*
+ * 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.
+ */
+struct mem_cgroup {
+ struct cgroup_subsys_state css;
+
+ /* Accounted resources */
+ struct page_counter memory;
+ struct page_counter memsw;
+ struct page_counter kmem;
+
+ /* Normal memory consumption range */
+ unsigned long low;
+ unsigned long high;
+
+ unsigned long soft_limit;
+
+ /* vmpressure notifications */
+ struct vmpressure vmpressure;
+
+ /* css_online() has been completed */
+ int initialized;
+
+ /*
+ * Should the accounting and control be hierarchical, per subtree?
+ */
+ bool use_hierarchy;
+
+ bool oom_lock;
+ atomic_t under_oom;
+ atomic_t oom_wakeups;
+
+ int swappiness;
+ /* OOM-Killer disable */
+ int oom_kill_disable;
+
+ /* protect arrays of thresholds */
+ struct mutex thresholds_lock;
+
+ /* thresholds for memory usage. RCU-protected */
+ struct mem_cgroup_thresholds thresholds;
+
+ /* thresholds for mem+swap usage. RCU-protected */
+ struct mem_cgroup_thresholds memsw_thresholds;
+
+ /* For oom notifier event fd */
+ struct list_head oom_notify;
+
+ /*
+ * Should we move charges of a task when a task is moved into this
+ * mem_cgroup ? And what type of charges should we move ?
+ */
+ unsigned long move_charge_at_immigrate;
+ /*
+ * set > 0 if pages under this cgroup are moving to other cgroup.
+ */
+ atomic_t moving_account;
+ /* taken only while moving_account > 0 */
+ spinlock_t move_lock;
+ struct task_struct *move_lock_task;
+ unsigned long move_lock_flags;
+ /*
+ * percpu counter.
+ */
+ struct mem_cgroup_stat_cpu __percpu *stat;
+ /*
+ * used when a cpu is offlined or other synchronizations
+ * See mem_cgroup_read_stat().
+ */
+ struct mem_cgroup_stat_cpu nocpu_base;
+ spinlock_t pcp_counter_lock;
+
+#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
+ struct cg_proto tcp_mem;
+#endif
+#if defined(CONFIG_MEMCG_KMEM)
+ /* Index in the kmem_cache->memcg_params.memcg_caches array */
+ int kmemcg_id;
+ bool kmem_acct_activated;
+ bool kmem_acct_active;
+#endif
+
+ int last_scanned_node;
+#if MAX_NUMNODES > 1
+ nodemask_t scan_nodes;
+ atomic_t numainfo_events;
+ atomic_t numainfo_updating;
+#endif
+
+ /* List of events which userspace want to receive */
+ struct list_head event_list;
+ spinlock_t event_list_lock;
+
+ struct mem_cgroup_per_node *nodeinfo[0];
+ /* WARNING: nodeinfo must be the last member here */
+};
+
+#ifdef CONFIG_MEMCG_KMEM
+bool memcg_kmem_is_active(struct mem_cgroup *memcg)
+{
+ return memcg->kmem_acct_active;
+}
+#endif
+
+/* Stuffs for move charges at task migration. */
+/*
+ * Types of charges to be moved.
+ */
+#define MOVE_ANON 0x1U
+#define MOVE_FILE 0x2U
+#define MOVE_MASK (MOVE_ANON | MOVE_FILE)
+
+/* "mc" and its members are protected by cgroup_mutex */
+static struct move_charge_struct {
+ spinlock_t lock; /* for from, to */
+ struct mem_cgroup *from;
+ struct mem_cgroup *to;
+ unsigned long flags;
+ unsigned long precharge;
+ unsigned long moved_charge;
+ unsigned long moved_swap;
+ struct task_struct *moving_task; /* a task moving charges */
+ wait_queue_head_t waitq; /* a waitq for other context */
+} mc = {
+ .lock = __SPIN_LOCK_UNLOCKED(mc.lock),
+ .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
+};
+
+/*
+ * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
+ * limit reclaim to prevent infinite loops, if they ever occur.
+ */
+#define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
+#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
+
+enum charge_type {
+ MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
+ MEM_CGROUP_CHARGE_TYPE_ANON,
+ MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
+ MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
+ NR_CHARGE_TYPE,
+};
+
+/* for encoding cft->private value on file */
+enum res_type {
+ _MEM,
+ _MEMSWAP,
+ _OOM_TYPE,
+ _KMEM,
+};
+
+#define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
+#define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
+#define MEMFILE_ATTR(val) ((val) & 0xffff)
+/* Used for OOM nofiier */
+#define OOM_CONTROL (0)
+
+/*
+ * The memcg_create_mutex will be held whenever a new cgroup is created.
+ * As a consequence, any change that needs to protect against new child cgroups
+ * appearing has to hold it as well.
+ */
+static DEFINE_MUTEX(memcg_create_mutex);
+
+struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s)
+{
+ return s ? container_of(s, struct mem_cgroup, css) : NULL;
+}
+
+/* Some nice accessors for the vmpressure. */
+struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg)
+{
+ if (!memcg)
+ memcg = root_mem_cgroup;
+ return &memcg->vmpressure;
+}
+
+struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr)
+{
+ return &container_of(vmpr, struct mem_cgroup, vmpressure)->css;
+}
+
+static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
+{
+ return (memcg == root_mem_cgroup);
+}
+
+/*
+ * We restrict the id in the range of [1, 65535], so it can fit into
+ * an unsigned short.
+ */
+#define MEM_CGROUP_ID_MAX USHRT_MAX
+
+static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
+{
+ return memcg->css.id;
+}
+
+/*
+ * A helper function to get mem_cgroup from ID. must be called under
+ * rcu_read_lock(). The caller is responsible for calling
+ * css_tryget_online() if the mem_cgroup is used for charging. (dropping
+ * refcnt from swap can be called against removed memcg.)
+ */
+static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
+{
+ struct cgroup_subsys_state *css;
+
+ css = css_from_id(id, &memory_cgrp_subsys);
+ return mem_cgroup_from_css(css);
+}
+
+/* Writing them here to avoid exposing memcg's inner layout */
+#if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
+
+void sock_update_memcg(struct sock *sk)
+{
+ if (mem_cgroup_sockets_enabled) {
+ struct mem_cgroup *memcg;
+ struct cg_proto *cg_proto;
+
+ BUG_ON(!sk->sk_prot->proto_cgroup);
+
+ /* Socket cloning can throw us here with sk_cgrp already
+ * filled. It won't however, necessarily happen from
+ * process context. So the test for root memcg given
+ * the current task's memcg won't help us in this case.
+ *
+ * Respecting the original socket's memcg is a better
+ * decision in this case.
+ */
+ if (sk->sk_cgrp) {
+ BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg));
+ css_get(&sk->sk_cgrp->memcg->css);
+ return;
+ }
+
+ rcu_read_lock();
+ memcg = mem_cgroup_from_task(current);
+ cg_proto = sk->sk_prot->proto_cgroup(memcg);
+ if (!mem_cgroup_is_root(memcg) &&
+ memcg_proto_active(cg_proto) &&
+ css_tryget_online(&memcg->css)) {
+ sk->sk_cgrp = cg_proto;
+ }
+ rcu_read_unlock();
+ }
+}
+EXPORT_SYMBOL(sock_update_memcg);
+
+void sock_release_memcg(struct sock *sk)
+{
+ if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
+ struct mem_cgroup *memcg;
+ WARN_ON(!sk->sk_cgrp->memcg);
+ memcg = sk->sk_cgrp->memcg;
+ css_put(&sk->sk_cgrp->memcg->css);
+ }
+}
+
+struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
+{
+ if (!memcg || mem_cgroup_is_root(memcg))
+ return NULL;
+
+ return &memcg->tcp_mem;
+}
+EXPORT_SYMBOL(tcp_proto_cgroup);
+
+#endif
+
+#ifdef CONFIG_MEMCG_KMEM
+/*
+ * This will be the memcg's index in each cache's ->memcg_params.memcg_caches.
+ * The main reason for not using cgroup id for this:
+ * this works better in sparse environments, where we have a lot of memcgs,
+ * but only a few kmem-limited. Or also, if we have, for instance, 200
+ * memcgs, and none but the 200th is kmem-limited, we'd have to have a
+ * 200 entry array for that.
+ *
+ * The current size of the caches array is stored in memcg_nr_cache_ids. It
+ * will double each time we have to increase it.
+ */
+static DEFINE_IDA(memcg_cache_ida);
+int memcg_nr_cache_ids;
+
+/* Protects memcg_nr_cache_ids */
+static DECLARE_RWSEM(memcg_cache_ids_sem);
+
+void memcg_get_cache_ids(void)
+{
+ down_read(&memcg_cache_ids_sem);
+}
+
+void memcg_put_cache_ids(void)
+{
+ up_read(&memcg_cache_ids_sem);
+}
+
+/*
+ * MIN_SIZE is different than 1, because we would like to avoid going through
+ * the alloc/free process all the time. In a small machine, 4 kmem-limited
+ * cgroups is a reasonable guess. In the future, it could be a parameter or
+ * tunable, but that is strictly not necessary.
+ *
+ * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
+ * this constant directly from cgroup, but it is understandable that this is
+ * better kept as an internal representation in cgroup.c. In any case, the
+ * cgrp_id space is not getting any smaller, and we don't have to necessarily
+ * increase ours as well if it increases.
+ */
+#define MEMCG_CACHES_MIN_SIZE 4
+#define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
+
+/*
+ * A lot of the calls to the cache allocation functions are expected to be
+ * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
+ * conditional to this static branch, we'll have to allow modules that does
+ * kmem_cache_alloc and the such to see this symbol as well
+ */
+struct static_key memcg_kmem_enabled_key;
+EXPORT_SYMBOL(memcg_kmem_enabled_key);
+
+#endif /* CONFIG_MEMCG_KMEM */
+
+static struct mem_cgroup_per_zone *
+mem_cgroup_zone_zoneinfo(struct mem_cgroup *memcg, struct zone *zone)
+{
+ int nid = zone_to_nid(zone);
+ int zid = zone_idx(zone);
+
+ return &memcg->nodeinfo[nid]->zoneinfo[zid];
+}
+
+struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg)
+{
+ return &memcg->css;
+}
+
+static struct mem_cgroup_per_zone *
+mem_cgroup_page_zoneinfo(struct mem_cgroup *memcg, struct page *page)
+{
+ int nid = page_to_nid(page);
+ int zid = page_zonenum(page);
+
+ return &memcg->nodeinfo[nid]->zoneinfo[zid];
+}
+
+static struct mem_cgroup_tree_per_zone *
+soft_limit_tree_node_zone(int nid, int zid)
+{
+ return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
+}
+
+static struct mem_cgroup_tree_per_zone *
+soft_limit_tree_from_page(struct page *page)
+{
+ int nid = page_to_nid(page);
+ int zid = page_zonenum(page);
+
+ return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
+}
+
+static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone *mz,
+ struct mem_cgroup_tree_per_zone *mctz,
+ unsigned long new_usage_in_excess)
+{
+ struct rb_node **p = &mctz->rb_root.rb_node;
+ struct rb_node *parent = NULL;
+ struct mem_cgroup_per_zone *mz_node;
+
+ if (mz->on_tree)
+ return;
+
+ mz->usage_in_excess = new_usage_in_excess;
+ if (!mz->usage_in_excess)
+ return;
+ while (*p) {
+ parent = *p;
+ mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
+ tree_node);
+ if (mz->usage_in_excess < mz_node->usage_in_excess)
+ p = &(*p)->rb_left;
+ /*
+ * We can't avoid mem cgroups that are over their soft
+ * limit by the same amount
+ */
+ else if (mz->usage_in_excess >= mz_node->usage_in_excess)
+ p = &(*p)->rb_right;
+ }
+ rb_link_node(&mz->tree_node, parent, p);
+ rb_insert_color(&mz->tree_node, &mctz->rb_root);
+ mz->on_tree = true;
+}
+
+static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone *mz,
+ struct mem_cgroup_tree_per_zone *mctz)
+{
+ if (!mz->on_tree)
+ return;
+ rb_erase(&mz->tree_node, &mctz->rb_root);
+ mz->on_tree = false;
+}
+
+static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone *mz,
+ struct mem_cgroup_tree_per_zone *mctz)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&mctz->lock, flags);
+ __mem_cgroup_remove_exceeded(mz, mctz);
+ spin_unlock_irqrestore(&mctz->lock, flags);
+}
+
+static unsigned long soft_limit_excess(struct mem_cgroup *memcg)
+{
+ unsigned long nr_pages = page_counter_read(&memcg->memory);
+ unsigned long soft_limit = READ_ONCE(memcg->soft_limit);
+ unsigned long excess = 0;
+
+ if (nr_pages > soft_limit)
+ excess = nr_pages - soft_limit;
+
+ return excess;
+}
+
+static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page)
+{
+ unsigned long excess;
+ struct mem_cgroup_per_zone *mz;
+ struct mem_cgroup_tree_per_zone *mctz;
+
+ mctz = soft_limit_tree_from_page(page);
+ /*
+ * Necessary to update all ancestors when hierarchy is used.
+ * because their event counter is not touched.
+ */
+ for (; memcg; memcg = parent_mem_cgroup(memcg)) {
+ mz = mem_cgroup_page_zoneinfo(memcg, page);
+ excess = soft_limit_excess(memcg);
+ /*
+ * We have to update the tree if mz is on RB-tree or
+ * mem is over its softlimit.
+ */
+ if (excess || mz->on_tree) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&mctz->lock, flags);
+ /* if on-tree, remove it */
+ if (mz->on_tree)
+ __mem_cgroup_remove_exceeded(mz, mctz);
+ /*
+ * Insert again. mz->usage_in_excess will be updated.
+ * If excess is 0, no tree ops.
+ */
+ __mem_cgroup_insert_exceeded(mz, mctz, excess);
+ spin_unlock_irqrestore(&mctz->lock, flags);
+ }
+ }
+}
+
+static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup_tree_per_zone *mctz;
+ struct mem_cgroup_per_zone *mz;
+ int nid, zid;
+
+ for_each_node(nid) {
+ for (zid = 0; zid < MAX_NR_ZONES; zid++) {
+ mz = &memcg->nodeinfo[nid]->zoneinfo[zid];
+ mctz = soft_limit_tree_node_zone(nid, zid);
+ mem_cgroup_remove_exceeded(mz, mctz);
+ }
+ }
+}
+
+static struct mem_cgroup_per_zone *
+__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
+{
+ struct rb_node *rightmost = NULL;
+ struct mem_cgroup_per_zone *mz;
+
+retry:
+ mz = NULL;
+ rightmost = rb_last(&mctz->rb_root);
+ if (!rightmost)
+ goto done; /* Nothing to reclaim from */
+
+ mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
+ /*
+ * Remove the node now but someone else can add it back,
+ * we will to add it back at the end of reclaim to its correct
+ * position in the tree.
+ */
+ __mem_cgroup_remove_exceeded(mz, mctz);
+ if (!soft_limit_excess(mz->memcg) ||
+ !css_tryget_online(&mz->memcg->css))
+ goto retry;
+done:
+ return mz;
+}
+
+static struct mem_cgroup_per_zone *
+mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
+{
+ struct mem_cgroup_per_zone *mz;
+
+ spin_lock_irq(&mctz->lock);
+ mz = __mem_cgroup_largest_soft_limit_node(mctz);
+ spin_unlock_irq(&mctz->lock);
+ return mz;
+}
+
+/*
+ * Implementation Note: reading percpu statistics for memcg.
+ *
+ * Both of vmstat[] and percpu_counter has threshold and do periodic
+ * synchronization to implement "quick" read. There are trade-off between
+ * reading cost and precision of value. Then, we may have a chance to implement
+ * a periodic synchronizion of counter in memcg's counter.
+ *
+ * But this _read() function is used for user interface now. The user accounts
+ * memory usage by memory cgroup and he _always_ requires exact value because
+ * he accounts memory. Even if we provide quick-and-fuzzy read, we always
+ * have to visit all online cpus and make sum. So, for now, unnecessary
+ * synchronization is not implemented. (just implemented for cpu hotplug)
+ *
+ * If there are kernel internal actions which can make use of some not-exact
+ * value, and reading all cpu value can be performance bottleneck in some
+ * common workload, threashold and synchonization as vmstat[] should be
+ * implemented.
+ */
+static long mem_cgroup_read_stat(struct mem_cgroup *memcg,
+ enum mem_cgroup_stat_index idx)
+{
+ long val = 0;
+ int cpu;
+
+ get_online_cpus();
+ for_each_online_cpu(cpu)
+ val += per_cpu(memcg->stat->count[idx], cpu);
+#ifdef CONFIG_HOTPLUG_CPU
+ spin_lock(&memcg->pcp_counter_lock);
+ val += memcg->nocpu_base.count[idx];
+ spin_unlock(&memcg->pcp_counter_lock);
+#endif
+ put_online_cpus();
+ return val;
+}
+
+static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg,
+ enum mem_cgroup_events_index idx)
+{
+ unsigned long val = 0;
+ int cpu;
+
+ get_online_cpus();
+ for_each_online_cpu(cpu)
+ val += per_cpu(memcg->stat->events[idx], cpu);
+#ifdef CONFIG_HOTPLUG_CPU
+ spin_lock(&memcg->pcp_counter_lock);
+ val += memcg->nocpu_base.events[idx];
+ spin_unlock(&memcg->pcp_counter_lock);
+#endif
+ put_online_cpus();
+ return val;
+}
+
+static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
+ struct page *page,
+ int nr_pages)
+{
+ /*
+ * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
+ * counted as CACHE even if it's on ANON LRU.
+ */
+ if (PageAnon(page))
+ __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS],
+ nr_pages);
+ else
+ __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE],
+ nr_pages);
+
+ if (PageTransHuge(page))
+ __this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE],
+ nr_pages);
+
+ /* pagein of a big page is an event. So, ignore page size */
+ if (nr_pages > 0)
+ __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]);
+ else {
+ __this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]);
+ nr_pages = -nr_pages; /* for event */
+ }
+
+ __this_cpu_add(memcg->stat->nr_page_events, nr_pages);
+}
+
+unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
+{
+ struct mem_cgroup_per_zone *mz;
+
+ mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
+ return mz->lru_size[lru];
+}
+
+static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
+ int nid,
+ unsigned int lru_mask)
+{
+ unsigned long nr = 0;
+ int zid;
+
+ VM_BUG_ON((unsigned)nid >= nr_node_ids);
+
+ for (zid = 0; zid < MAX_NR_ZONES; zid++) {
+ struct mem_cgroup_per_zone *mz;
+ enum lru_list lru;
+
+ for_each_lru(lru) {
+ if (!(BIT(lru) & lru_mask))
+ continue;
+ mz = &memcg->nodeinfo[nid]->zoneinfo[zid];
+ nr += mz->lru_size[lru];
+ }
+ }
+ return nr;
+}
+
+static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
+ unsigned int lru_mask)
+{
+ unsigned long nr = 0;
+ int nid;
+
+ for_each_node_state(nid, N_MEMORY)
+ nr += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask);
+ return nr;
+}
+
+static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
+ enum mem_cgroup_events_target target)
+{
+ unsigned long val, next;
+
+ val = __this_cpu_read(memcg->stat->nr_page_events);
+ next = __this_cpu_read(memcg->stat->targets[target]);
+ /* from time_after() in jiffies.h */
+ if ((long)next - (long)val < 0) {
+ switch (target) {
+ case MEM_CGROUP_TARGET_THRESH:
+ next = val + THRESHOLDS_EVENTS_TARGET;
+ break;
+ case MEM_CGROUP_TARGET_SOFTLIMIT:
+ next = val + SOFTLIMIT_EVENTS_TARGET;
+ break;
+ case MEM_CGROUP_TARGET_NUMAINFO:
+ next = val + NUMAINFO_EVENTS_TARGET;
+ break;
+ default:
+ break;
+ }
+ __this_cpu_write(memcg->stat->targets[target], next);
+ return true;
+ }
+ return false;
+}
+
+/*
+ * Check events in order.
+ *
+ */
+static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
+{
+ /* threshold event is triggered in finer grain than soft limit */
+ if (unlikely(mem_cgroup_event_ratelimit(memcg,
+ MEM_CGROUP_TARGET_THRESH))) {
+ bool do_softlimit;
+ bool do_numainfo __maybe_unused;
+
+ do_softlimit = mem_cgroup_event_ratelimit(memcg,
+ MEM_CGROUP_TARGET_SOFTLIMIT);
+#if MAX_NUMNODES > 1
+ do_numainfo = mem_cgroup_event_ratelimit(memcg,
+ MEM_CGROUP_TARGET_NUMAINFO);
+#endif
+ mem_cgroup_threshold(memcg);
+ if (unlikely(do_softlimit))
+ mem_cgroup_update_tree(memcg, page);
+#if MAX_NUMNODES > 1
+ if (unlikely(do_numainfo))
+ atomic_inc(&memcg->numainfo_events);
+#endif
+ }
+}
+
+struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
+{
+ /*
+ * mm_update_next_owner() may clear mm->owner to NULL
+ * if it races with swapoff, page migration, etc.
+ * So this can be called with p == NULL.
+ */
+ if (unlikely(!p))
+ return NULL;
+
+ return mem_cgroup_from_css(task_css(p, memory_cgrp_id));
+}
+
+static struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm)
+{
+ struct mem_cgroup *memcg = NULL;
+
+ rcu_read_lock();
+ do {
+ /*
+ * Page cache insertions can happen withou an
+ * actual mm context, e.g. during disk probing
+ * on boot, loopback IO, acct() writes etc.
+ */
+ if (unlikely(!mm))
+ memcg = root_mem_cgroup;
+ else {
+ memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
+ if (unlikely(!memcg))
+ memcg = root_mem_cgroup;
+ }
+ } while (!css_tryget_online(&memcg->css));
+ rcu_read_unlock();
+ return memcg;
+}
+
+/**
+ * mem_cgroup_iter - iterate over memory cgroup hierarchy
+ * @root: hierarchy root
+ * @prev: previously returned memcg, NULL on first invocation
+ * @reclaim: cookie for shared reclaim walks, NULL for full walks
+ *
+ * Returns references to children of the hierarchy below @root, or
+ * @root itself, or %NULL after a full round-trip.
+ *
+ * Caller must pass the return value in @prev on subsequent
+ * invocations for reference counting, or use mem_cgroup_iter_break()
+ * to cancel a hierarchy walk before the round-trip is complete.
+ *
+ * Reclaimers can specify a zone and a priority level in @reclaim to
+ * divide up the memcgs in the hierarchy among all concurrent
+ * reclaimers operating on the same zone and priority.
+ */
+struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
+ struct mem_cgroup *prev,
+ struct mem_cgroup_reclaim_cookie *reclaim)
+{
+ struct reclaim_iter *uninitialized_var(iter);
+ struct cgroup_subsys_state *css = NULL;
+ struct mem_cgroup *memcg = NULL;
+ struct mem_cgroup *pos = NULL;
+
+ if (mem_cgroup_disabled())
+ return NULL;
+
+ if (!root)
+ root = root_mem_cgroup;
+
+ if (prev && !reclaim)
+ pos = prev;
+
+ if (!root->use_hierarchy && root != root_mem_cgroup) {
+ if (prev)
+ goto out;
+ return root;
+ }
+
+ rcu_read_lock();
+
+ if (reclaim) {
+ struct mem_cgroup_per_zone *mz;
+
+ mz = mem_cgroup_zone_zoneinfo(root, reclaim->zone);
+ iter = &mz->iter[reclaim->priority];
+
+ if (prev && reclaim->generation != iter->generation)
+ goto out_unlock;
+
+ do {
+ pos = READ_ONCE(iter->position);
+ /*
+ * A racing update may change the position and
+ * put the last reference, hence css_tryget(),
+ * or retry to see the updated position.
+ */
+ } while (pos && !css_tryget(&pos->css));
+ }
+
+ if (pos)
+ css = &pos->css;
+
+ for (;;) {
+ css = css_next_descendant_pre(css, &root->css);
+ if (!css) {
+ /*
+ * Reclaimers share the hierarchy walk, and a
+ * new one might jump in right at the end of
+ * the hierarchy - make sure they see at least
+ * one group and restart from the beginning.
+ */
+ if (!prev)
+ continue;
+ break;
+ }
+
+ /*
+ * Verify the css and acquire a reference. The root
+ * is provided by the caller, so we know it's alive
+ * and kicking, and don't take an extra reference.
+ */
+ memcg = mem_cgroup_from_css(css);
+
+ if (css == &root->css)
+ break;
+
+ if (css_tryget(css)) {
+ /*
+ * Make sure the memcg is initialized:
+ * mem_cgroup_css_online() orders the the
+ * initialization against setting the flag.
+ */
+ if (smp_load_acquire(&memcg->initialized))
+ break;
+
+ css_put(css);
+ }
+
+ memcg = NULL;
+ }
+
+ if (reclaim) {
+ if (cmpxchg(&iter->position, pos, memcg) == pos) {
+ if (memcg)
+ css_get(&memcg->css);
+ if (pos)
+ css_put(&pos->css);
+ }
+
+ /*
+ * pairs with css_tryget when dereferencing iter->position
+ * above.
+ */
+ if (pos)
+ css_put(&pos->css);
+
+ if (!memcg)
+ iter->generation++;
+ else if (!prev)
+ reclaim->generation = iter->generation;
+ }
+
+out_unlock:
+ rcu_read_unlock();
+out:
+ if (prev && prev != root)
+ css_put(&prev->css);
+
+ return memcg;
+}
+
+/**
+ * mem_cgroup_iter_break - abort a hierarchy walk prematurely
+ * @root: hierarchy root
+ * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
+ */
+void mem_cgroup_iter_break(struct mem_cgroup *root,
+ struct mem_cgroup *prev)
+{
+ if (!root)
+ root = root_mem_cgroup;
+ if (prev && prev != root)
+ css_put(&prev->css);
+}
+
+/*
+ * Iteration constructs for visiting all cgroups (under a tree). If
+ * loops are exited prematurely (break), mem_cgroup_iter_break() must
+ * be used for reference counting.
+ */
+#define for_each_mem_cgroup_tree(iter, root) \
+ for (iter = mem_cgroup_iter(root, NULL, NULL); \
+ iter != NULL; \
+ iter = mem_cgroup_iter(root, iter, NULL))
+
+#define for_each_mem_cgroup(iter) \
+ for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
+ iter != NULL; \
+ iter = mem_cgroup_iter(NULL, iter, NULL))
+
+void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
+{
+ struct mem_cgroup *memcg;
+
+ rcu_read_lock();
+ memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
+ if (unlikely(!memcg))
+ goto out;
+
+ switch (idx) {
+ case PGFAULT:
+ this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]);
+ break;
+ case PGMAJFAULT:
+ this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]);
+ break;
+ default:
+ BUG();
+ }
+out:
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL(__mem_cgroup_count_vm_event);
+
+/**
+ * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
+ * @zone: zone of the wanted lruvec
+ * @memcg: memcg of the wanted lruvec
+ *
+ * Returns the lru list vector holding pages for the given @zone and
+ * @mem. This can be the global zone lruvec, if the memory controller
+ * is disabled.
+ */
+struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
+ struct mem_cgroup *memcg)
+{
+ struct mem_cgroup_per_zone *mz;
+ struct lruvec *lruvec;
+
+ if (mem_cgroup_disabled()) {
+ lruvec = &zone->lruvec;
+ goto out;
+ }
+
+ mz = mem_cgroup_zone_zoneinfo(memcg, zone);
+ lruvec = &mz->lruvec;
+out:
+ /*
+ * Since a node can be onlined after the mem_cgroup was created,
+ * we have to be prepared to initialize lruvec->zone here;
+ * and if offlined then reonlined, we need to reinitialize it.
+ */
+ if (unlikely(lruvec->zone != zone))
+ lruvec->zone = zone;
+ return lruvec;
+}
+
+/**
+ * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
+ * @page: the page
+ * @zone: zone of the page
+ *
+ * This function is only safe when following the LRU page isolation
+ * and putback protocol: the LRU lock must be held, and the page must
+ * either be PageLRU() or the caller must have isolated/allocated it.
+ */
+struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone)
+{
+ struct mem_cgroup_per_zone *mz;
+ struct mem_cgroup *memcg;
+ struct lruvec *lruvec;
+
+ if (mem_cgroup_disabled()) {
+ lruvec = &zone->lruvec;
+ goto out;
+ }
+
+ memcg = page->mem_cgroup;
+ /*
+ * Swapcache readahead pages are added to the LRU - and
+ * possibly migrated - before they are charged.
+ */
+ if (!memcg)
+ memcg = root_mem_cgroup;
+
+ mz = mem_cgroup_page_zoneinfo(memcg, page);
+ lruvec = &mz->lruvec;
+out:
+ /*
+ * Since a node can be onlined after the mem_cgroup was created,
+ * we have to be prepared to initialize lruvec->zone here;
+ * and if offlined then reonlined, we need to reinitialize it.
+ */
+ if (unlikely(lruvec->zone != zone))
+ lruvec->zone = zone;
+ return lruvec;
+}
+
+/**
+ * mem_cgroup_update_lru_size - account for adding or removing an lru page
+ * @lruvec: mem_cgroup per zone lru vector
+ * @lru: index of lru list the page is sitting on
+ * @nr_pages: positive when adding or negative when removing
+ *
+ * This function must be called when a page is added to or removed from an
+ * lru list.
+ */
+void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
+ int nr_pages)
+{
+ struct mem_cgroup_per_zone *mz;
+ unsigned long *lru_size;
+
+ if (mem_cgroup_disabled())
+ return;
+
+ mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
+ lru_size = mz->lru_size + lru;
+ *lru_size += nr_pages;
+ VM_BUG_ON((long)(*lru_size) < 0);
+}
+
+bool mem_cgroup_is_descendant(struct mem_cgroup *memcg, struct mem_cgroup *root)
+{
+ if (root == memcg)
+ return true;
+ if (!root->use_hierarchy)
+ return false;
+ return cgroup_is_descendant(memcg->css.cgroup, root->css.cgroup);
+}
+
+bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *task_memcg;
+ struct task_struct *p;
+ bool ret;
+
+ p = find_lock_task_mm(task);
+ if (p) {
+ task_memcg = get_mem_cgroup_from_mm(p->mm);
+ task_unlock(p);
+ } else {
+ /*
+ * All threads may have already detached their mm's, but the oom
+ * killer still needs to detect if they have already been oom
+ * killed to prevent needlessly killing additional tasks.
+ */
+ rcu_read_lock();
+ task_memcg = mem_cgroup_from_task(task);
+ css_get(&task_memcg->css);
+ rcu_read_unlock();
+ }
+ ret = mem_cgroup_is_descendant(task_memcg, memcg);
+ css_put(&task_memcg->css);
+ return ret;
+}
+
+int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
+{
+ unsigned long inactive_ratio;
+ unsigned long inactive;
+ unsigned long active;
+ unsigned long gb;
+
+ inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON);
+ active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON);
+
+ gb = (inactive + active) >> (30 - PAGE_SHIFT);
+ if (gb)
+ inactive_ratio = int_sqrt(10 * gb);
+ else
+ inactive_ratio = 1;
+
+ return inactive * inactive_ratio < active;
+}
+
+bool mem_cgroup_lruvec_online(struct lruvec *lruvec)
+{
+ struct mem_cgroup_per_zone *mz;
+ struct mem_cgroup *memcg;
+
+ if (mem_cgroup_disabled())
+ return true;
+
+ mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
+ memcg = mz->memcg;
+
+ return !!(memcg->css.flags & CSS_ONLINE);
+}
+
+#define mem_cgroup_from_counter(counter, member) \
+ container_of(counter, struct mem_cgroup, member)
+
+/**
+ * mem_cgroup_margin - calculate chargeable space of a memory cgroup
+ * @memcg: the memory cgroup
+ *
+ * Returns the maximum amount of memory @mem can be charged with, in
+ * pages.
+ */
+static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg)
+{
+ unsigned long margin = 0;
+ unsigned long count;
+ unsigned long limit;
+
+ count = page_counter_read(&memcg->memory);
+ limit = READ_ONCE(memcg->memory.limit);
+ if (count < limit)
+ margin = limit - count;
+
+ if (do_swap_account) {
+ count = page_counter_read(&memcg->memsw);
+ limit = READ_ONCE(memcg->memsw.limit);
+ if (count <= limit)
+ margin = min(margin, limit - count);
+ }
+
+ return margin;
+}
+
+int mem_cgroup_swappiness(struct mem_cgroup *memcg)
+{
+ /* root ? */
+ if (mem_cgroup_disabled() || !memcg->css.parent)
+ return vm_swappiness;
+
+ return memcg->swappiness;
+}
+
+/*
+ * A routine for checking "mem" is under move_account() or not.
+ *
+ * Checking a cgroup is mc.from or mc.to or under hierarchy of
+ * moving cgroups. This is for waiting at high-memory pressure
+ * caused by "move".
+ */
+static bool mem_cgroup_under_move(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *from;
+ struct mem_cgroup *to;
+ bool ret = false;
+ /*
+ * Unlike task_move routines, we access mc.to, mc.from not under
+ * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
+ */
+ spin_lock(&mc.lock);
+ from = mc.from;
+ to = mc.to;
+ if (!from)
+ goto unlock;
+
+ ret = mem_cgroup_is_descendant(from, memcg) ||
+ mem_cgroup_is_descendant(to, memcg);
+unlock:
+ spin_unlock(&mc.lock);
+ return ret;
+}
+
+static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg)
+{
+ if (mc.moving_task && current != mc.moving_task) {
+ if (mem_cgroup_under_move(memcg)) {
+ DEFINE_WAIT(wait);
+ prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
+ /* moving charge context might have finished. */
+ if (mc.moving_task)
+ schedule();
+ finish_wait(&mc.waitq, &wait);
+ return true;
+ }
+ }
+ return false;
+}
+
+#define K(x) ((x) << (PAGE_SHIFT-10))
+/**
+ * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
+ * @memcg: The memory cgroup that went over limit
+ * @p: Task that is going to be killed
+ *
+ * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
+ * enabled
+ */
+void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
+{
+ /* oom_info_lock ensures that parallel ooms do not interleave */
+ static DEFINE_MUTEX(oom_info_lock);
+ struct mem_cgroup *iter;
+ unsigned int i;
+
+ mutex_lock(&oom_info_lock);
+ rcu_read_lock();
+
+ if (p) {
+ pr_info("Task in ");
+ pr_cont_cgroup_path(task_cgroup(p, memory_cgrp_id));
+ pr_cont(" killed as a result of limit of ");
+ } else {
+ pr_info("Memory limit reached of cgroup ");
+ }
+
+ pr_cont_cgroup_path(memcg->css.cgroup);
+ pr_cont("\n");
+
+ rcu_read_unlock();
+
+ pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
+ K((u64)page_counter_read(&memcg->memory)),
+ K((u64)memcg->memory.limit), memcg->memory.failcnt);
+ pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
+ K((u64)page_counter_read(&memcg->memsw)),
+ K((u64)memcg->memsw.limit), memcg->memsw.failcnt);
+ pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
+ K((u64)page_counter_read(&memcg->kmem)),
+ K((u64)memcg->kmem.limit), memcg->kmem.failcnt);
+
+ for_each_mem_cgroup_tree(iter, memcg) {
+ pr_info("Memory cgroup stats for ");
+ pr_cont_cgroup_path(iter->css.cgroup);
+ pr_cont(":");
+
+ for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
+ if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
+ continue;
+ pr_cont(" %s:%ldKB", mem_cgroup_stat_names[i],
+ K(mem_cgroup_read_stat(iter, i)));
+ }
+
+ for (i = 0; i < NR_LRU_LISTS; i++)
+ pr_cont(" %s:%luKB", mem_cgroup_lru_names[i],
+ K(mem_cgroup_nr_lru_pages(iter, BIT(i))));
+
+ pr_cont("\n");
+ }
+ mutex_unlock(&oom_info_lock);
+}
+
+/*
+ * This function returns the number of memcg under hierarchy tree. Returns
+ * 1(self count) if no children.
+ */
+static int mem_cgroup_count_children(struct mem_cgroup *memcg)
+{
+ int num = 0;
+ struct mem_cgroup *iter;
+
+ for_each_mem_cgroup_tree(iter, memcg)
+ num++;
+ return num;
+}
+
+/*
+ * Return the memory (and swap, if configured) limit for a memcg.
+ */
+static unsigned long mem_cgroup_get_limit(struct mem_cgroup *memcg)
+{
+ unsigned long limit;
+
+ limit = memcg->memory.limit;
+ if (mem_cgroup_swappiness(memcg)) {
+ unsigned long memsw_limit;
+
+ memsw_limit = memcg->memsw.limit;
+ limit = min(limit + total_swap_pages, memsw_limit);
+ }
+ return limit;
+}
+
+static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
+ int order)
+{
+ struct mem_cgroup *iter;
+ unsigned long chosen_points = 0;
+ unsigned long totalpages;
+ unsigned int points = 0;
+ struct task_struct *chosen = NULL;
+
+ /*
+ * If current has a pending SIGKILL or is exiting, then automatically
+ * select it. The goal is to allow it to allocate so that it may
+ * quickly exit and free its memory.
+ */
+ if (fatal_signal_pending(current) || task_will_free_mem(current)) {
+ mark_tsk_oom_victim(current);
+ return;
+ }
+
+ check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL, memcg);
+ totalpages = mem_cgroup_get_limit(memcg) ? : 1;
+ for_each_mem_cgroup_tree(iter, memcg) {
+ struct css_task_iter it;
+ struct task_struct *task;
+
+ css_task_iter_start(&iter->css, &it);
+ while ((task = css_task_iter_next(&it))) {
+ switch (oom_scan_process_thread(task, totalpages, NULL,
+ false)) {
+ case OOM_SCAN_SELECT:
+ if (chosen)
+ put_task_struct(chosen);
+ chosen = task;
+ chosen_points = ULONG_MAX;
+ get_task_struct(chosen);
+ /* fall through */
+ case OOM_SCAN_CONTINUE:
+ continue;
+ case OOM_SCAN_ABORT:
+ css_task_iter_end(&it);
+ mem_cgroup_iter_break(memcg, iter);
+ if (chosen)
+ put_task_struct(chosen);
+ return;
+ case OOM_SCAN_OK:
+ break;
+ };
+ points = oom_badness(task, memcg, NULL, totalpages);
+ if (!points || points < chosen_points)
+ continue;
+ /* Prefer thread group leaders for display purposes */
+ if (points == chosen_points &&
+ thread_group_leader(chosen))
+ continue;
+
+ if (chosen)
+ put_task_struct(chosen);
+ chosen = task;
+ chosen_points = points;
+ get_task_struct(chosen);
+ }
+ css_task_iter_end(&it);
+ }
+
+ if (!chosen)
+ return;
+ points = chosen_points * 1000 / totalpages;
+ oom_kill_process(chosen, gfp_mask, order, points, totalpages, memcg,
+ NULL, "Memory cgroup out of memory");
+}
+
+#if MAX_NUMNODES > 1
+
+/**
+ * test_mem_cgroup_node_reclaimable
+ * @memcg: the target memcg
+ * @nid: the node ID to be checked.
+ * @noswap : specify true here if the user wants flle only information.
+ *
+ * This function returns whether the specified memcg contains any
+ * reclaimable pages on a node. Returns true if there are any reclaimable
+ * pages in the node.
+ */
+static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg,
+ int nid, bool noswap)
+{
+ if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE))
+ return true;
+ if (noswap || !total_swap_pages)
+ return false;
+ if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON))
+ return true;
+ return false;
+
+}
+
+/*
+ * Always updating the nodemask is not very good - even if we have an empty
+ * list or the wrong list here, we can start from some node and traverse all
+ * nodes based on the zonelist. So update the list loosely once per 10 secs.
+ *
+ */
+static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg)
+{
+ int nid;
+ /*
+ * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
+ * pagein/pageout changes since the last update.
+ */
+ if (!atomic_read(&memcg->numainfo_events))
+ return;
+ if (atomic_inc_return(&memcg->numainfo_updating) > 1)
+ return;
+
+ /* make a nodemask where this memcg uses memory from */
+ memcg->scan_nodes = node_states[N_MEMORY];
+
+ for_each_node_mask(nid, node_states[N_MEMORY]) {
+
+ if (!test_mem_cgroup_node_reclaimable(memcg, nid, false))
+ node_clear(nid, memcg->scan_nodes);
+ }
+
+ atomic_set(&memcg->numainfo_events, 0);
+ atomic_set(&memcg->numainfo_updating, 0);
+}
+
+/*
+ * Selecting a node where we start reclaim from. Because what we need is just
+ * reducing usage counter, start from anywhere is O,K. Considering
+ * memory reclaim from current node, there are pros. and cons.
+ *
+ * Freeing memory from current node means freeing memory from a node which
+ * we'll use or we've used. So, it may make LRU bad. And if several threads
+ * hit limits, it will see a contention on a node. But freeing from remote
+ * node means more costs for memory reclaim because of memory latency.
+ *
+ * Now, we use round-robin. Better algorithm is welcomed.
+ */
+int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
+{
+ int node;
+
+ mem_cgroup_may_update_nodemask(memcg);
+ node = memcg->last_scanned_node;
+
+ node = next_node(node, memcg->scan_nodes);
+ if (node == MAX_NUMNODES)
+ node = first_node(memcg->scan_nodes);
+ /*
+ * We call this when we hit limit, not when pages are added to LRU.
+ * No LRU may hold pages because all pages are UNEVICTABLE or
+ * memcg is too small and all pages are not on LRU. In that case,
+ * we use curret node.
+ */
+ if (unlikely(node == MAX_NUMNODES))
+ node = numa_node_id();
+
+ memcg->last_scanned_node = node;
+ return node;
+}
+#else
+int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
+{
+ return 0;
+}
+#endif
+
+static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
+ struct zone *zone,
+ gfp_t gfp_mask,
+ unsigned long *total_scanned)
+{
+ struct mem_cgroup *victim = NULL;
+ int total = 0;
+ int loop = 0;
+ unsigned long excess;
+ unsigned long nr_scanned;
+ struct mem_cgroup_reclaim_cookie reclaim = {
+ .zone = zone,
+ .priority = 0,
+ };
+
+ excess = soft_limit_excess(root_memcg);
+
+ while (1) {
+ victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
+ if (!victim) {
+ loop++;
+ if (loop >= 2) {
+ /*
+ * If we have not been able to reclaim
+ * anything, it might because there are
+ * no reclaimable pages under this hierarchy
+ */
+ if (!total)
+ break;
+ /*
+ * We want to do more targeted reclaim.
+ * excess >> 2 is not to excessive so as to
+ * reclaim too much, nor too less that we keep
+ * coming back to reclaim from this cgroup
+ */
+ if (total >= (excess >> 2) ||
+ (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS))
+ break;
+ }
+ continue;
+ }
+ total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false,
+ zone, &nr_scanned);
+ *total_scanned += nr_scanned;
+ if (!soft_limit_excess(root_memcg))
+ break;
+ }
+ mem_cgroup_iter_break(root_memcg, victim);
+ return total;
+}
+
+#ifdef CONFIG_LOCKDEP
+static struct lockdep_map memcg_oom_lock_dep_map = {
+ .name = "memcg_oom_lock",
+};
+#endif
+
+static DEFINE_SPINLOCK(memcg_oom_lock);
+
+/*
+ * Check OOM-Killer is already running under our hierarchy.
+ * If someone is running, return false.
+ */
+static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter, *failed = NULL;
+
+ spin_lock(&memcg_oom_lock);
+
+ for_each_mem_cgroup_tree(iter, memcg) {
+ if (iter->oom_lock) {
+ /*
+ * this subtree of our hierarchy is already locked
+ * so we cannot give a lock.
+ */
+ failed = iter;
+ mem_cgroup_iter_break(memcg, iter);
+ break;
+ } else
+ iter->oom_lock = true;
+ }
+
+ if (failed) {
+ /*
+ * OK, we failed to lock the whole subtree so we have
+ * to clean up what we set up to the failing subtree
+ */
+ for_each_mem_cgroup_tree(iter, memcg) {
+ if (iter == failed) {
+ mem_cgroup_iter_break(memcg, iter);
+ break;
+ }
+ iter->oom_lock = false;
+ }
+ } else
+ mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_);
+
+ spin_unlock(&memcg_oom_lock);
+
+ return !failed;
+}
+
+static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter;
+
+ spin_lock(&memcg_oom_lock);
+ mutex_release(&memcg_oom_lock_dep_map, 1, _RET_IP_);
+ for_each_mem_cgroup_tree(iter, memcg)
+ iter->oom_lock = false;
+ spin_unlock(&memcg_oom_lock);
+}
+
+static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter;
+
+ for_each_mem_cgroup_tree(iter, memcg)
+ atomic_inc(&iter->under_oom);
+}
+
+static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter;
+
+ /*
+ * When a new child is created while the hierarchy is under oom,
+ * mem_cgroup_oom_lock() may not be called. We have to use
+ * atomic_add_unless() here.
+ */
+ for_each_mem_cgroup_tree(iter, memcg)
+ atomic_add_unless(&iter->under_oom, -1, 0);
+}
+
+static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
+
+struct oom_wait_info {
+ struct mem_cgroup *memcg;
+ wait_queue_t wait;
+};
+
+static int memcg_oom_wake_function(wait_queue_t *wait,
+ unsigned mode, int sync, void *arg)
+{
+ struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg;
+ struct mem_cgroup *oom_wait_memcg;
+ struct oom_wait_info *oom_wait_info;
+
+ oom_wait_info = container_of(wait, struct oom_wait_info, wait);
+ oom_wait_memcg = oom_wait_info->memcg;
+
+ if (!mem_cgroup_is_descendant(wake_memcg, oom_wait_memcg) &&
+ !mem_cgroup_is_descendant(oom_wait_memcg, wake_memcg))
+ return 0;
+ return autoremove_wake_function(wait, mode, sync, arg);
+}
+
+static void memcg_wakeup_oom(struct mem_cgroup *memcg)
+{
+ atomic_inc(&memcg->oom_wakeups);
+ /* for filtering, pass "memcg" as argument. */
+ __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg);
+}
+
+static void memcg_oom_recover(struct mem_cgroup *memcg)
+{
+ if (memcg && atomic_read(&memcg->under_oom))
+ memcg_wakeup_oom(memcg);
+}
+
+static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order)
+{
+ if (!current->memcg_oom.may_oom)
+ return;
+ /*
+ * We are in the middle of the charge context here, so we
+ * don't want to block when potentially sitting on a callstack
+ * that holds all kinds of filesystem and mm locks.
+ *
+ * Also, the caller may handle a failed allocation gracefully
+ * (like optional page cache readahead) and so an OOM killer
+ * invocation might not even be necessary.
+ *
+ * That's why we don't do anything here except remember the
+ * OOM context and then deal with it at the end of the page
+ * fault when the stack is unwound, the locks are released,
+ * and when we know whether the fault was overall successful.
+ */
+ css_get(&memcg->css);
+ current->memcg_oom.memcg = memcg;
+ current->memcg_oom.gfp_mask = mask;
+ current->memcg_oom.order = order;
+}
+
+/**
+ * mem_cgroup_oom_synchronize - complete memcg OOM handling
+ * @handle: actually kill/wait or just clean up the OOM state
+ *
+ * This has to be called at the end of a page fault if the memcg OOM
+ * handler was enabled.
+ *
+ * Memcg supports userspace OOM handling where failed allocations must
+ * sleep on a waitqueue until the userspace task resolves the
+ * situation. Sleeping directly in the charge context with all kinds
+ * of locks held is not a good idea, instead we remember an OOM state
+ * in the task and mem_cgroup_oom_synchronize() has to be called at
+ * the end of the page fault to complete the OOM handling.
+ *
+ * Returns %true if an ongoing memcg OOM situation was detected and
+ * completed, %false otherwise.
+ */
+bool mem_cgroup_oom_synchronize(bool handle)
+{
+ struct mem_cgroup *memcg = current->memcg_oom.memcg;
+ struct oom_wait_info owait;
+ bool locked;
+
+ /* OOM is global, do not handle */
+ if (!memcg)
+ return false;
+
+ if (!handle || oom_killer_disabled)
+ goto cleanup;
+
+ owait.memcg = memcg;
+ owait.wait.flags = 0;
+ owait.wait.func = memcg_oom_wake_function;
+ owait.wait.private = current;
+ INIT_LIST_HEAD(&owait.wait.task_list);
+
+ prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
+ mem_cgroup_mark_under_oom(memcg);
+
+ locked = mem_cgroup_oom_trylock(memcg);
+
+ if (locked)
+ mem_cgroup_oom_notify(memcg);
+
+ if (locked && !memcg->oom_kill_disable) {
+ mem_cgroup_unmark_under_oom(memcg);
+ finish_wait(&memcg_oom_waitq, &owait.wait);
+ mem_cgroup_out_of_memory(memcg, current->memcg_oom.gfp_mask,
+ current->memcg_oom.order);
+ } else {
+ schedule();
+ mem_cgroup_unmark_under_oom(memcg);
+ finish_wait(&memcg_oom_waitq, &owait.wait);
+ }
+
+ if (locked) {
+ mem_cgroup_oom_unlock(memcg);
+ /*
+ * There is no guarantee that an OOM-lock contender
+ * sees the wakeups triggered by the OOM kill
+ * uncharges. Wake any sleepers explicitely.
+ */
+ memcg_oom_recover(memcg);
+ }
+cleanup:
+ current->memcg_oom.memcg = NULL;
+ css_put(&memcg->css);
+ return true;
+}
+
+/**
+ * mem_cgroup_begin_page_stat - begin a page state statistics transaction
+ * @page: page that is going to change accounted state
+ *
+ * This function must mark the beginning of an accounted page state
+ * change to prevent double accounting when the page is concurrently
+ * being moved to another memcg:
+ *
+ * memcg = mem_cgroup_begin_page_stat(page);
+ * if (TestClearPageState(page))
+ * mem_cgroup_update_page_stat(memcg, state, -1);
+ * mem_cgroup_end_page_stat(memcg);
+ */
+struct mem_cgroup *mem_cgroup_begin_page_stat(struct page *page)
+{
+ struct mem_cgroup *memcg;
+ unsigned long flags;
+
+ /*
+ * The RCU lock is held throughout the transaction. The fast
+ * path can get away without acquiring the memcg->move_lock
+ * because page moving starts with an RCU grace period.
+ *
+ * The RCU lock also protects the memcg from being freed when
+ * the page state that is going to change is the only thing
+ * preventing the page from being uncharged.
+ * E.g. end-writeback clearing PageWriteback(), which allows
+ * migration to go ahead and uncharge the page before the
+ * account transaction might be complete.
+ */
+ rcu_read_lock();
+
+ if (mem_cgroup_disabled())
+ return NULL;
+again:
+ memcg = page->mem_cgroup;
+ if (unlikely(!memcg))
+ return NULL;
+
+ if (atomic_read(&memcg->moving_account) <= 0)
+ return memcg;
+
+ spin_lock_irqsave(&memcg->move_lock, flags);
+ if (memcg != page->mem_cgroup) {
+ spin_unlock_irqrestore(&memcg->move_lock, flags);
+ goto again;
+ }
+
+ /*
+ * When charge migration first begins, we can have locked and
+ * unlocked page stat updates happening concurrently. Track
+ * the task who has the lock for mem_cgroup_end_page_stat().
+ */
+ memcg->move_lock_task = current;
+ memcg->move_lock_flags = flags;
+
+ return memcg;
+}
+
+/**
+ * mem_cgroup_end_page_stat - finish a page state statistics transaction
+ * @memcg: the memcg that was accounted against
+ */
+void mem_cgroup_end_page_stat(struct mem_cgroup *memcg)
+{
+ if (memcg && memcg->move_lock_task == current) {
+ unsigned long flags = memcg->move_lock_flags;
+
+ memcg->move_lock_task = NULL;
+ memcg->move_lock_flags = 0;
+
+ spin_unlock_irqrestore(&memcg->move_lock, flags);
+ }
+
+ rcu_read_unlock();
+}
+
+/**
+ * mem_cgroup_update_page_stat - update page state statistics
+ * @memcg: memcg to account against
+ * @idx: page state item to account
+ * @val: number of pages (positive or negative)
+ *
+ * See mem_cgroup_begin_page_stat() for locking requirements.
+ */
+void mem_cgroup_update_page_stat(struct mem_cgroup *memcg,
+ enum mem_cgroup_stat_index idx, int val)
+{
+ VM_BUG_ON(!rcu_read_lock_held());
+
+ if (memcg)
+ this_cpu_add(memcg->stat->count[idx], val);
+}
+
+/*
+ * size of first charge trial. "32" comes from vmscan.c's magic value.
+ * TODO: maybe necessary to use big numbers in big irons.
+ */
+#define CHARGE_BATCH 32U
+struct memcg_stock_pcp {
+ struct mem_cgroup *cached; /* this never be root cgroup */
+ unsigned int nr_pages;
+ struct work_struct work;
+ unsigned long flags;
+#define FLUSHING_CACHED_CHARGE 0
+};
+static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
+static DEFINE_MUTEX(percpu_charge_mutex);
+
+/**
+ * consume_stock: Try to consume stocked charge on this cpu.
+ * @memcg: memcg to consume from.
+ * @nr_pages: how many pages to charge.
+ *
+ * The charges will only happen if @memcg matches the current cpu's memcg
+ * stock, and at least @nr_pages are available in that stock. Failure to
+ * service an allocation will refill the stock.
+ *
+ * returns true if successful, false otherwise.
+ */
+static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
+{
+ struct memcg_stock_pcp *stock;
+ bool ret = false;
+
+ if (nr_pages > CHARGE_BATCH)
+ return ret;
+
+ stock = &get_cpu_var(memcg_stock);
+ if (memcg == stock->cached && stock->nr_pages >= nr_pages) {
+ stock->nr_pages -= nr_pages;
+ ret = true;
+ }
+ put_cpu_var(memcg_stock);
+ return ret;
+}
+
+/*
+ * Returns stocks cached in percpu and reset cached information.
+ */
+static void drain_stock(struct memcg_stock_pcp *stock)
+{
+ struct mem_cgroup *old = stock->cached;
+
+ if (stock->nr_pages) {
+ page_counter_uncharge(&old->memory, stock->nr_pages);
+ if (do_swap_account)
+ page_counter_uncharge(&old->memsw, stock->nr_pages);
+ css_put_many(&old->css, stock->nr_pages);
+ stock->nr_pages = 0;
+ }
+ stock->cached = NULL;
+}
+
+/*
+ * This must be called under preempt disabled or must be called by
+ * a thread which is pinned to local cpu.
+ */
+static void drain_local_stock(struct work_struct *dummy)
+{
+ struct memcg_stock_pcp *stock = this_cpu_ptr(&memcg_stock);
+ drain_stock(stock);
+ clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
+}
+
+/*
+ * Cache charges(val) to local per_cpu area.
+ * This will be consumed by consume_stock() function, later.
+ */
+static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
+{
+ struct memcg_stock_pcp *stock;
+ int cpu = get_cpu_light();
+
+ stock = &per_cpu(memcg_stock, cpu);
+
+ if (stock->cached != memcg) { /* reset if necessary */
+ drain_stock(stock);
+ stock->cached = memcg;
+ }
+ stock->nr_pages += nr_pages;
+ put_cpu_light();
+}
+
+/*
+ * Drains all per-CPU charge caches for given root_memcg resp. subtree
+ * of the hierarchy under it.
+ */
+static void drain_all_stock(struct mem_cgroup *root_memcg)
+{
+ int cpu, curcpu;
+
+ /* If someone's already draining, avoid adding running more workers. */
+ if (!mutex_trylock(&percpu_charge_mutex))
+ return;
+ /* Notify other cpus that system-wide "drain" is running */
+ get_online_cpus();
+ curcpu = get_cpu_light();
+ for_each_online_cpu(cpu) {
+ struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
+ struct mem_cgroup *memcg;
+
+ memcg = stock->cached;
+ if (!memcg || !stock->nr_pages)
+ continue;
+ if (!mem_cgroup_is_descendant(memcg, root_memcg))
+ continue;
+ if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) {
+ if (cpu == curcpu)
+ drain_local_stock(&stock->work);
+ else
+ schedule_work_on(cpu, &stock->work);
+ }
+ }
+ put_cpu_light();
+ put_online_cpus();
+ mutex_unlock(&percpu_charge_mutex);
+}
+
+/*
+ * This function drains percpu counter value from DEAD cpu and
+ * move it to local cpu. Note that this function can be preempted.
+ */
+static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu)
+{
+ int i;
+
+ spin_lock(&memcg->pcp_counter_lock);
+ for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
+ long x = per_cpu(memcg->stat->count[i], cpu);
+
+ per_cpu(memcg->stat->count[i], cpu) = 0;
+ memcg->nocpu_base.count[i] += x;
+ }
+ for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
+ unsigned long x = per_cpu(memcg->stat->events[i], cpu);
+
+ per_cpu(memcg->stat->events[i], cpu) = 0;
+ memcg->nocpu_base.events[i] += x;
+ }
+ spin_unlock(&memcg->pcp_counter_lock);
+}
+
+static int memcg_cpu_hotplug_callback(struct notifier_block *nb,
+ unsigned long action,
+ void *hcpu)
+{
+ int cpu = (unsigned long)hcpu;
+ struct memcg_stock_pcp *stock;
+ struct mem_cgroup *iter;
+
+ if (action == CPU_ONLINE)
+ return NOTIFY_OK;
+
+ if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
+ return NOTIFY_OK;
+
+ for_each_mem_cgroup(iter)
+ mem_cgroup_drain_pcp_counter(iter, cpu);
+
+ stock = &per_cpu(memcg_stock, cpu);
+ drain_stock(stock);
+ return NOTIFY_OK;
+}
+
+static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
+ unsigned int nr_pages)
+{
+ unsigned int batch = max(CHARGE_BATCH, nr_pages);
+ int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
+ struct mem_cgroup *mem_over_limit;
+ struct page_counter *counter;
+ unsigned long nr_reclaimed;
+ bool may_swap = true;
+ bool drained = false;
+ int ret = 0;
+
+ if (mem_cgroup_is_root(memcg))
+ goto done;
+retry:
+ if (consume_stock(memcg, nr_pages))
+ goto done;
+
+ if (!do_swap_account ||
+ !page_counter_try_charge(&memcg->memsw, batch, &counter)) {
+ if (!page_counter_try_charge(&memcg->memory, batch, &counter))
+ goto done_restock;
+ if (do_swap_account)
+ page_counter_uncharge(&memcg->memsw, batch);
+ mem_over_limit = mem_cgroup_from_counter(counter, memory);
+ } else {
+ mem_over_limit = mem_cgroup_from_counter(counter, memsw);
+ may_swap = false;
+ }
+
+ if (batch > nr_pages) {
+ batch = nr_pages;
+ goto retry;
+ }
+
+ /*
+ * Unlike in global OOM situations, memcg is not in a physical
+ * memory shortage. Allow dying and OOM-killed tasks to
+ * bypass the last charges so that they can exit quickly and
+ * free their memory.
+ */
+ if (unlikely(test_thread_flag(TIF_MEMDIE) ||
+ fatal_signal_pending(current) ||
+ current->flags & PF_EXITING))
+ goto bypass;
+
+ if (unlikely(task_in_memcg_oom(current)))
+ goto nomem;
+
+ if (!(gfp_mask & __GFP_WAIT))
+ goto nomem;
+
+ mem_cgroup_events(mem_over_limit, MEMCG_MAX, 1);
+
+ nr_reclaimed = try_to_free_mem_cgroup_pages(mem_over_limit, nr_pages,
+ gfp_mask, may_swap);
+
+ if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
+ goto retry;
+
+ if (!drained) {
+ drain_all_stock(mem_over_limit);
+ drained = true;
+ goto retry;
+ }
+
+ if (gfp_mask & __GFP_NORETRY)
+ goto nomem;
+ /*
+ * Even though the limit is exceeded at this point, reclaim
+ * may have been able to free some pages. Retry the charge
+ * before killing the task.
+ *
+ * Only for regular pages, though: huge pages are rather
+ * unlikely to succeed so close to the limit, and we fall back
+ * to regular pages anyway in case of failure.
+ */
+ if (nr_reclaimed && nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER))
+ goto retry;
+ /*
+ * At task move, charge accounts can be doubly counted. So, it's
+ * better to wait until the end of task_move if something is going on.
+ */
+ if (mem_cgroup_wait_acct_move(mem_over_limit))
+ goto retry;
+
+ if (nr_retries--)
+ goto retry;
+
+ if (gfp_mask & __GFP_NOFAIL)
+ goto bypass;
+
+ if (fatal_signal_pending(current))
+ goto bypass;
+
+ mem_cgroup_events(mem_over_limit, MEMCG_OOM, 1);
+
+ mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(nr_pages));
+nomem:
+ if (!(gfp_mask & __GFP_NOFAIL))
+ return -ENOMEM;
+bypass:
+ return -EINTR;
+
+done_restock:
+ css_get_many(&memcg->css, batch);
+ if (batch > nr_pages)
+ refill_stock(memcg, batch - nr_pages);
+ if (!(gfp_mask & __GFP_WAIT))
+ goto done;
+ /*
+ * If the hierarchy is above the normal consumption range,
+ * make the charging task trim their excess contribution.
+ */
+ do {
+ if (page_counter_read(&memcg->memory) <= memcg->high)
+ continue;
+ mem_cgroup_events(memcg, MEMCG_HIGH, 1);
+ try_to_free_mem_cgroup_pages(memcg, nr_pages, gfp_mask, true);
+ } while ((memcg = parent_mem_cgroup(memcg)));
+done:
+ return ret;
+}
+
+static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
+{
+ if (mem_cgroup_is_root(memcg))
+ return;
+
+ page_counter_uncharge(&memcg->memory, nr_pages);
+ if (do_swap_account)
+ page_counter_uncharge(&memcg->memsw, nr_pages);
+
+ css_put_many(&memcg->css, nr_pages);
+}
+
+/*
+ * try_get_mem_cgroup_from_page - look up page's memcg association
+ * @page: the page
+ *
+ * Look up, get a css reference, and return the memcg that owns @page.
+ *
+ * The page must be locked to prevent racing with swap-in and page
+ * cache charges. If coming from an unlocked page table, the caller
+ * must ensure the page is on the LRU or this can race with charging.
+ */
+struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
+{
+ struct mem_cgroup *memcg;
+ unsigned short id;
+ swp_entry_t ent;
+
+ VM_BUG_ON_PAGE(!PageLocked(page), page);
+
+ memcg = page->mem_cgroup;
+ if (memcg) {
+ if (!css_tryget_online(&memcg->css))
+ memcg = NULL;
+ } else if (PageSwapCache(page)) {
+ ent.val = page_private(page);
+ id = lookup_swap_cgroup_id(ent);
+ rcu_read_lock();
+ memcg = mem_cgroup_from_id(id);
+ if (memcg && !css_tryget_online(&memcg->css))
+ memcg = NULL;
+ rcu_read_unlock();
+ }
+ return memcg;
+}
+
+static void lock_page_lru(struct page *page, int *isolated)
+{
+ struct zone *zone = page_zone(page);
+
+ spin_lock_irq(&zone->lru_lock);
+ if (PageLRU(page)) {
+ struct lruvec *lruvec;
+
+ lruvec = mem_cgroup_page_lruvec(page, zone);
+ ClearPageLRU(page);
+ del_page_from_lru_list(page, lruvec, page_lru(page));
+ *isolated = 1;
+ } else
+ *isolated = 0;
+}
+
+static void unlock_page_lru(struct page *page, int isolated)
+{
+ struct zone *zone = page_zone(page);
+
+ if (isolated) {
+ struct lruvec *lruvec;
+
+ lruvec = mem_cgroup_page_lruvec(page, zone);
+ VM_BUG_ON_PAGE(PageLRU(page), page);
+ SetPageLRU(page);
+ add_page_to_lru_list(page, lruvec, page_lru(page));
+ }
+ spin_unlock_irq(&zone->lru_lock);
+}
+
+static void commit_charge(struct page *page, struct mem_cgroup *memcg,
+ bool lrucare)
+{
+ int isolated;
+
+ VM_BUG_ON_PAGE(page->mem_cgroup, page);
+
+ /*
+ * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
+ * may already be on some other mem_cgroup's LRU. Take care of it.
+ */
+ if (lrucare)
+ lock_page_lru(page, &isolated);
+
+ /*
+ * Nobody should be changing or seriously looking at
+ * page->mem_cgroup at this point:
+ *
+ * - the page is uncharged
+ *
+ * - the page is off-LRU
+ *
+ * - an anonymous fault has exclusive page access, except for
+ * a locked page table
+ *
+ * - a page cache insertion, a swapin fault, or a migration
+ * have the page locked
+ */
+ page->mem_cgroup = memcg;
+
+ if (lrucare)
+ unlock_page_lru(page, isolated);
+}
+
+#ifdef CONFIG_MEMCG_KMEM
+int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp,
+ unsigned long nr_pages)
+{
+ struct page_counter *counter;
+ int ret = 0;
+
+ ret = page_counter_try_charge(&memcg->kmem, nr_pages, &counter);
+ if (ret < 0)
+ return ret;
+
+ ret = try_charge(memcg, gfp, nr_pages);
+ if (ret == -EINTR) {
+ /*
+ * try_charge() chose to bypass to root due to OOM kill or
+ * fatal signal. Since our only options are to either fail
+ * the allocation or charge it to this cgroup, do it as a
+ * temporary condition. But we can't fail. From a kmem/slab
+ * perspective, the cache has already been selected, by
+ * mem_cgroup_kmem_get_cache(), so it is too late to change
+ * our minds.
+ *
+ * This condition will only trigger if the task entered
+ * memcg_charge_kmem in a sane state, but was OOM-killed
+ * during try_charge() above. Tasks that were already dying
+ * when the allocation triggers should have been already
+ * directed to the root cgroup in memcontrol.h
+ */
+ page_counter_charge(&memcg->memory, nr_pages);
+ if (do_swap_account)
+ page_counter_charge(&memcg->memsw, nr_pages);
+ css_get_many(&memcg->css, nr_pages);
+ ret = 0;
+ } else if (ret)
+ page_counter_uncharge(&memcg->kmem, nr_pages);
+
+ return ret;
+}
+
+void memcg_uncharge_kmem(struct mem_cgroup *memcg, unsigned long nr_pages)
+{
+ page_counter_uncharge(&memcg->memory, nr_pages);
+ if (do_swap_account)
+ page_counter_uncharge(&memcg->memsw, nr_pages);
+
+ page_counter_uncharge(&memcg->kmem, nr_pages);
+
+ css_put_many(&memcg->css, nr_pages);
+}
+
+/*
+ * helper for acessing a memcg's index. It will be used as an index in the
+ * child cache array in kmem_cache, and also to derive its name. This function
+ * will return -1 when this is not a kmem-limited memcg.
+ */
+int memcg_cache_id(struct mem_cgroup *memcg)
+{
+ return memcg ? memcg->kmemcg_id : -1;
+}
+
+static int memcg_alloc_cache_id(void)
+{
+ int id, size;
+ int err;
+
+ id = ida_simple_get(&memcg_cache_ida,
+ 0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL);
+ if (id < 0)
+ return id;
+
+ if (id < memcg_nr_cache_ids)
+ return id;
+
+ /*
+ * There's no space for the new id in memcg_caches arrays,
+ * so we have to grow them.
+ */
+ down_write(&memcg_cache_ids_sem);
+
+ size = 2 * (id + 1);
+ if (size < MEMCG_CACHES_MIN_SIZE)
+ size = MEMCG_CACHES_MIN_SIZE;
+ else if (size > MEMCG_CACHES_MAX_SIZE)
+ size = MEMCG_CACHES_MAX_SIZE;
+
+ err = memcg_update_all_caches(size);
+ if (!err)
+ err = memcg_update_all_list_lrus(size);
+ if (!err)
+ memcg_nr_cache_ids = size;
+
+ up_write(&memcg_cache_ids_sem);
+
+ if (err) {
+ ida_simple_remove(&memcg_cache_ida, id);
+ return err;
+ }
+ return id;
+}
+
+static void memcg_free_cache_id(int id)
+{
+ ida_simple_remove(&memcg_cache_ida, id);
+}
+
+struct memcg_kmem_cache_create_work {
+ struct mem_cgroup *memcg;
+ struct kmem_cache *cachep;
+ struct work_struct work;
+};
+
+static void memcg_kmem_cache_create_func(struct work_struct *w)
+{
+ struct memcg_kmem_cache_create_work *cw =
+ container_of(w, struct memcg_kmem_cache_create_work, work);
+ struct mem_cgroup *memcg = cw->memcg;
+ struct kmem_cache *cachep = cw->cachep;
+
+ memcg_create_kmem_cache(memcg, cachep);
+
+ css_put(&memcg->css);
+ kfree(cw);
+}
+
+/*
+ * Enqueue the creation of a per-memcg kmem_cache.
+ */
+static void __memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
+ struct kmem_cache *cachep)
+{
+ struct memcg_kmem_cache_create_work *cw;
+
+ cw = kmalloc(sizeof(*cw), GFP_NOWAIT);
+ if (!cw)
+ return;
+
+ css_get(&memcg->css);
+
+ cw->memcg = memcg;
+ cw->cachep = cachep;
+ INIT_WORK(&cw->work, memcg_kmem_cache_create_func);
+
+ schedule_work(&cw->work);
+}
+
+static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
+ struct kmem_cache *cachep)
+{
+ /*
+ * We need to stop accounting when we kmalloc, because if the
+ * corresponding kmalloc cache is not yet created, the first allocation
+ * in __memcg_schedule_kmem_cache_create will recurse.
+ *
+ * However, it is better to enclose the whole function. Depending on
+ * the debugging options enabled, INIT_WORK(), for instance, can
+ * trigger an allocation. This too, will make us recurse. Because at
+ * this point we can't allow ourselves back into memcg_kmem_get_cache,
+ * the safest choice is to do it like this, wrapping the whole function.
+ */
+ current->memcg_kmem_skip_account = 1;
+ __memcg_schedule_kmem_cache_create(memcg, cachep);
+ current->memcg_kmem_skip_account = 0;
+}
+
+/*
+ * Return the kmem_cache we're supposed to use for a slab allocation.
+ * We try to use the current memcg's version of the cache.
+ *
+ * If the cache does not exist yet, if we are the first user of it,
+ * we either create it immediately, if possible, or create it asynchronously
+ * in a workqueue.
+ * In the latter case, we will let the current allocation go through with
+ * the original cache.
+ *
+ * Can't be called in interrupt context or from kernel threads.
+ * This function needs to be called with rcu_read_lock() held.
+ */
+struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep)
+{
+ struct mem_cgroup *memcg;
+ struct kmem_cache *memcg_cachep;
+ int kmemcg_id;
+
+ VM_BUG_ON(!is_root_cache(cachep));
+
+ if (current->memcg_kmem_skip_account)
+ return cachep;
+
+ memcg = get_mem_cgroup_from_mm(current->mm);
+ kmemcg_id = READ_ONCE(memcg->kmemcg_id);
+ if (kmemcg_id < 0)
+ goto out;
+
+ memcg_cachep = cache_from_memcg_idx(cachep, kmemcg_id);
+ if (likely(memcg_cachep))
+ return memcg_cachep;
+
+ /*
+ * If we are in a safe context (can wait, and not in interrupt
+ * context), we could be be predictable and return right away.
+ * This would guarantee that the allocation being performed
+ * already belongs in the new cache.
+ *
+ * However, there are some clashes that can arrive from locking.
+ * For instance, because we acquire the slab_mutex while doing
+ * memcg_create_kmem_cache, this means no further allocation
+ * could happen with the slab_mutex held. So it's better to
+ * defer everything.
+ */
+ memcg_schedule_kmem_cache_create(memcg, cachep);
+out:
+ css_put(&memcg->css);
+ return cachep;
+}
+
+void __memcg_kmem_put_cache(struct kmem_cache *cachep)
+{
+ if (!is_root_cache(cachep))
+ css_put(&cachep->memcg_params.memcg->css);
+}
+
+/*
+ * We need to verify if the allocation against current->mm->owner's memcg is
+ * possible for the given order. But the page is not allocated yet, so we'll
+ * need a further commit step to do the final arrangements.
+ *
+ * It is possible for the task to switch cgroups in this mean time, so at
+ * commit time, we can't rely on task conversion any longer. We'll then use
+ * the handle argument to return to the caller which cgroup we should commit
+ * against. We could also return the memcg directly and avoid the pointer
+ * passing, but a boolean return value gives better semantics considering
+ * the compiled-out case as well.
+ *
+ * Returning true means the allocation is possible.
+ */
+bool
+__memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order)
+{
+ struct mem_cgroup *memcg;
+ int ret;
+
+ *_memcg = NULL;
+
+ memcg = get_mem_cgroup_from_mm(current->mm);
+
+ if (!memcg_kmem_is_active(memcg)) {
+ css_put(&memcg->css);
+ return true;
+ }
+
+ ret = memcg_charge_kmem(memcg, gfp, 1 << order);
+ if (!ret)
+ *_memcg = memcg;
+
+ css_put(&memcg->css);
+ return (ret == 0);
+}
+
+void __memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg,
+ int order)
+{
+ VM_BUG_ON(mem_cgroup_is_root(memcg));
+
+ /* The page allocation failed. Revert */
+ if (!page) {
+ memcg_uncharge_kmem(memcg, 1 << order);
+ return;
+ }
+ page->mem_cgroup = memcg;
+}
+
+void __memcg_kmem_uncharge_pages(struct page *page, int order)
+{
+ struct mem_cgroup *memcg = page->mem_cgroup;
+
+ if (!memcg)
+ return;
+
+ VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg), page);
+
+ memcg_uncharge_kmem(memcg, 1 << order);
+ page->mem_cgroup = NULL;
+}
+
+struct mem_cgroup *__mem_cgroup_from_kmem(void *ptr)
+{
+ struct mem_cgroup *memcg = NULL;
+ struct kmem_cache *cachep;
+ struct page *page;
+
+ page = virt_to_head_page(ptr);
+ if (PageSlab(page)) {
+ cachep = page->slab_cache;
+ if (!is_root_cache(cachep))
+ memcg = cachep->memcg_params.memcg;
+ } else
+ /* page allocated by alloc_kmem_pages */
+ memcg = page->mem_cgroup;
+
+ return memcg;
+}
+#endif /* CONFIG_MEMCG_KMEM */
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+
+/*
+ * Because tail pages are not marked as "used", set it. We're under
+ * zone->lru_lock, 'splitting on pmd' and compound_lock.
+ * charge/uncharge will be never happen and move_account() is done under
+ * compound_lock(), so we don't have to take care of races.
+ */
+void mem_cgroup_split_huge_fixup(struct page *head)
+{
+ int i;
+
+ if (mem_cgroup_disabled())
+ return;
+
+ for (i = 1; i < HPAGE_PMD_NR; i++)
+ head[i].mem_cgroup = head->mem_cgroup;
+
+ __this_cpu_sub(head->mem_cgroup->stat->count[MEM_CGROUP_STAT_RSS_HUGE],
+ HPAGE_PMD_NR);
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+#ifdef CONFIG_MEMCG_SWAP
+static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,
+ bool charge)
+{
+ int val = (charge) ? 1 : -1;
+ this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val);
+}
+
+/**
+ * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
+ * @entry: swap entry to be moved
+ * @from: mem_cgroup which the entry is moved from
+ * @to: mem_cgroup which the entry is moved to
+ *
+ * It succeeds only when the swap_cgroup's record for this entry is the same
+ * as the mem_cgroup's id of @from.
+ *
+ * Returns 0 on success, -EINVAL on failure.
+ *
+ * The caller must have charged to @to, IOW, called page_counter_charge() about
+ * both res and memsw, and called css_get().
+ */
+static int mem_cgroup_move_swap_account(swp_entry_t entry,
+ struct mem_cgroup *from, struct mem_cgroup *to)
+{
+ unsigned short old_id, new_id;
+
+ old_id = mem_cgroup_id(from);
+ new_id = mem_cgroup_id(to);
+
+ if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
+ mem_cgroup_swap_statistics(from, false);
+ mem_cgroup_swap_statistics(to, true);
+ return 0;
+ }
+ return -EINVAL;
+}
+#else
+static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
+ struct mem_cgroup *from, struct mem_cgroup *to)
+{
+ return -EINVAL;
+}
+#endif
+
+static DEFINE_MUTEX(memcg_limit_mutex);
+
+static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
+ unsigned long limit)
+{
+ unsigned long curusage;
+ unsigned long oldusage;
+ bool enlarge = false;
+ int retry_count;
+ int ret;
+
+ /*
+ * For keeping hierarchical_reclaim simple, how long we should retry
+ * is depends on callers. We set our retry-count to be function
+ * of # of children which we should visit in this loop.
+ */
+ retry_count = MEM_CGROUP_RECLAIM_RETRIES *
+ mem_cgroup_count_children(memcg);
+
+ oldusage = page_counter_read(&memcg->memory);
+
+ do {
+ if (signal_pending(current)) {
+ ret = -EINTR;
+ break;
+ }
+
+ mutex_lock(&memcg_limit_mutex);
+ if (limit > memcg->memsw.limit) {
+ mutex_unlock(&memcg_limit_mutex);
+ ret = -EINVAL;
+ break;
+ }
+ if (limit > memcg->memory.limit)
+ enlarge = true;
+ ret = page_counter_limit(&memcg->memory, limit);
+ mutex_unlock(&memcg_limit_mutex);
+
+ if (!ret)
+ break;
+
+ try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, true);
+
+ curusage = page_counter_read(&memcg->memory);
+ /* Usage is reduced ? */
+ if (curusage >= oldusage)
+ retry_count--;
+ else
+ oldusage = curusage;
+ } while (retry_count);
+
+ if (!ret && enlarge)
+ memcg_oom_recover(memcg);
+
+ return ret;
+}
+
+static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
+ unsigned long limit)
+{
+ unsigned long curusage;
+ unsigned long oldusage;
+ bool enlarge = false;
+ int retry_count;
+ int ret;
+
+ /* see mem_cgroup_resize_res_limit */
+ retry_count = MEM_CGROUP_RECLAIM_RETRIES *
+ mem_cgroup_count_children(memcg);
+
+ oldusage = page_counter_read(&memcg->memsw);
+
+ do {
+ if (signal_pending(current)) {
+ ret = -EINTR;
+ break;
+ }
+
+ mutex_lock(&memcg_limit_mutex);
+ if (limit < memcg->memory.limit) {
+ mutex_unlock(&memcg_limit_mutex);
+ ret = -EINVAL;
+ break;
+ }
+ if (limit > memcg->memsw.limit)
+ enlarge = true;
+ ret = page_counter_limit(&memcg->memsw, limit);
+ mutex_unlock(&memcg_limit_mutex);
+
+ if (!ret)
+ break;
+
+ try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, false);
+
+ curusage = page_counter_read(&memcg->memsw);
+ /* Usage is reduced ? */
+ if (curusage >= oldusage)
+ retry_count--;
+ else
+ oldusage = curusage;
+ } while (retry_count);
+
+ if (!ret && enlarge)
+ memcg_oom_recover(memcg);
+
+ return ret;
+}
+
+unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
+ gfp_t gfp_mask,
+ unsigned long *total_scanned)
+{
+ unsigned long nr_reclaimed = 0;
+ struct mem_cgroup_per_zone *mz, *next_mz = NULL;
+ unsigned long reclaimed;
+ int loop = 0;
+ struct mem_cgroup_tree_per_zone *mctz;
+ unsigned long excess;
+ unsigned long nr_scanned;
+
+ if (order > 0)
+ return 0;
+
+ mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone));
+ /*
+ * This loop can run a while, specially if mem_cgroup's continuously
+ * keep exceeding their soft limit and putting the system under
+ * pressure
+ */
+ do {
+ if (next_mz)
+ mz = next_mz;
+ else
+ mz = mem_cgroup_largest_soft_limit_node(mctz);
+ if (!mz)
+ break;
+
+ nr_scanned = 0;
+ reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone,
+ gfp_mask, &nr_scanned);
+ nr_reclaimed += reclaimed;
+ *total_scanned += nr_scanned;
+ spin_lock_irq(&mctz->lock);
+ __mem_cgroup_remove_exceeded(mz, mctz);
+
+ /*
+ * If we failed to reclaim anything from this memory cgroup
+ * it is time to move on to the next cgroup
+ */
+ next_mz = NULL;
+ if (!reclaimed)
+ next_mz = __mem_cgroup_largest_soft_limit_node(mctz);
+
+ excess = soft_limit_excess(mz->memcg);
+ /*
+ * One school of thought says that we should not add
+ * back the node to the tree if reclaim returns 0.
+ * But our reclaim could return 0, simply because due
+ * to priority we are exposing a smaller subset of
+ * memory to reclaim from. Consider this as a longer
+ * term TODO.
+ */
+ /* If excess == 0, no tree ops */
+ __mem_cgroup_insert_exceeded(mz, mctz, excess);
+ spin_unlock_irq(&mctz->lock);
+ css_put(&mz->memcg->css);
+ loop++;
+ /*
+ * Could not reclaim anything and there are no more
+ * mem cgroups to try or we seem to be looping without
+ * reclaiming anything.
+ */
+ if (!nr_reclaimed &&
+ (next_mz == NULL ||
+ loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
+ break;
+ } while (!nr_reclaimed);
+ if (next_mz)
+ css_put(&next_mz->memcg->css);
+ return nr_reclaimed;
+}
+
+/*
+ * Test whether @memcg has children, dead or alive. Note that this
+ * function doesn't care whether @memcg has use_hierarchy enabled and
+ * returns %true if there are child csses according to the cgroup
+ * hierarchy. Testing use_hierarchy is the caller's responsiblity.
+ */
+static inline bool memcg_has_children(struct mem_cgroup *memcg)
+{
+ bool ret;
+
+ /*
+ * The lock does not prevent addition or deletion of children, but
+ * it prevents a new child from being initialized based on this
+ * parent in css_online(), so it's enough to decide whether
+ * hierarchically inherited attributes can still be changed or not.
+ */
+ lockdep_assert_held(&memcg_create_mutex);
+
+ rcu_read_lock();
+ ret = css_next_child(NULL, &memcg->css);
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Reclaims as many pages from the given memcg as possible and moves
+ * the rest to the parent.
+ *
+ * Caller is responsible for holding css reference for memcg.
+ */
+static int mem_cgroup_force_empty(struct mem_cgroup *memcg)
+{
+ int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
+
+ /* we call try-to-free pages for make this cgroup empty */
+ lru_add_drain_all();
+ /* try to free all pages in this cgroup */
+ while (nr_retries && page_counter_read(&memcg->memory)) {
+ int progress;
+
+ if (signal_pending(current))
+ return -EINTR;
+
+ progress = try_to_free_mem_cgroup_pages(memcg, 1,
+ GFP_KERNEL, true);
+ if (!progress) {
+ nr_retries--;
+ /* maybe some writeback is necessary */
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
+ }
+
+ }
+
+ return 0;
+}
+
+static ssize_t mem_cgroup_force_empty_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes,
+ loff_t off)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
+
+ if (mem_cgroup_is_root(memcg))
+ return -EINVAL;
+ return mem_cgroup_force_empty(memcg) ?: nbytes;
+}
+
+static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ return mem_cgroup_from_css(css)->use_hierarchy;
+}
+
+static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
+{
+ int retval = 0;
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct mem_cgroup *parent_memcg = mem_cgroup_from_css(memcg->css.parent);
+
+ mutex_lock(&memcg_create_mutex);
+
+ if (memcg->use_hierarchy == val)
+ goto out;
+
+ /*
+ * If parent's use_hierarchy is set, we can't make any modifications
+ * in the child subtrees. If it is unset, then the change can
+ * occur, provided the current cgroup has no children.
+ *
+ * For the root cgroup, parent_mem is NULL, we allow value to be
+ * set if there are no children.
+ */
+ if ((!parent_memcg || !parent_memcg->use_hierarchy) &&
+ (val == 1 || val == 0)) {
+ if (!memcg_has_children(memcg))
+ memcg->use_hierarchy = val;
+ else
+ retval = -EBUSY;
+ } else
+ retval = -EINVAL;
+
+out:
+ mutex_unlock(&memcg_create_mutex);
+
+ return retval;
+}
+
+static unsigned long tree_stat(struct mem_cgroup *memcg,
+ enum mem_cgroup_stat_index idx)
+{
+ struct mem_cgroup *iter;
+ long val = 0;
+
+ /* Per-cpu values can be negative, use a signed accumulator */
+ for_each_mem_cgroup_tree(iter, memcg)
+ val += mem_cgroup_read_stat(iter, idx);
+
+ if (val < 0) /* race ? */
+ val = 0;
+ return val;
+}
+
+static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
+{
+ u64 val;
+
+ if (mem_cgroup_is_root(memcg)) {
+ val = tree_stat(memcg, MEM_CGROUP_STAT_CACHE);
+ val += tree_stat(memcg, MEM_CGROUP_STAT_RSS);
+ if (swap)
+ val += tree_stat(memcg, MEM_CGROUP_STAT_SWAP);
+ } else {
+ if (!swap)
+ val = page_counter_read(&memcg->memory);
+ else
+ val = page_counter_read(&memcg->memsw);
+ }
+ return val << PAGE_SHIFT;
+}
+
+enum {
+ RES_USAGE,
+ RES_LIMIT,
+ RES_MAX_USAGE,
+ RES_FAILCNT,
+ RES_SOFT_LIMIT,
+};
+
+static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct page_counter *counter;
+
+ switch (MEMFILE_TYPE(cft->private)) {
+ case _MEM:
+ counter = &memcg->memory;
+ break;
+ case _MEMSWAP:
+ counter = &memcg->memsw;
+ break;
+ case _KMEM:
+ counter = &memcg->kmem;
+ break;
+ default:
+ BUG();
+ }
+
+ switch (MEMFILE_ATTR(cft->private)) {
+ case RES_USAGE:
+ if (counter == &memcg->memory)
+ return mem_cgroup_usage(memcg, false);
+ if (counter == &memcg->memsw)
+ return mem_cgroup_usage(memcg, true);
+ return (u64)page_counter_read(counter) * PAGE_SIZE;
+ case RES_LIMIT:
+ return (u64)counter->limit * PAGE_SIZE;
+ case RES_MAX_USAGE:
+ return (u64)counter->watermark * PAGE_SIZE;
+ case RES_FAILCNT:
+ return counter->failcnt;
+ case RES_SOFT_LIMIT:
+ return (u64)memcg->soft_limit * PAGE_SIZE;
+ default:
+ BUG();
+ }
+}
+
+#ifdef CONFIG_MEMCG_KMEM
+static int memcg_activate_kmem(struct mem_cgroup *memcg,
+ unsigned long nr_pages)
+{
+ int err = 0;
+ int memcg_id;
+
+ BUG_ON(memcg->kmemcg_id >= 0);
+ BUG_ON(memcg->kmem_acct_activated);
+ BUG_ON(memcg->kmem_acct_active);
+
+ /*
+ * For simplicity, we won't allow this to be disabled. It also can't
+ * be changed if the cgroup has children already, or if tasks had
+ * already joined.
+ *
+ * If tasks join before we set the limit, a person looking at
+ * kmem.usage_in_bytes will have no way to determine when it took
+ * place, which makes the value quite meaningless.
+ *
+ * After it first became limited, changes in the value of the limit are
+ * of course permitted.
+ */
+ mutex_lock(&memcg_create_mutex);
+ if (cgroup_has_tasks(memcg->css.cgroup) ||
+ (memcg->use_hierarchy && memcg_has_children(memcg)))
+ err = -EBUSY;
+ mutex_unlock(&memcg_create_mutex);
+ if (err)
+ goto out;
+
+ memcg_id = memcg_alloc_cache_id();
+ if (memcg_id < 0) {
+ err = memcg_id;
+ goto out;
+ }
+
+ /*
+ * We couldn't have accounted to this cgroup, because it hasn't got
+ * activated yet, so this should succeed.
+ */
+ err = page_counter_limit(&memcg->kmem, nr_pages);
+ VM_BUG_ON(err);
+
+ static_key_slow_inc(&memcg_kmem_enabled_key);
+ /*
+ * A memory cgroup is considered kmem-active as soon as it gets
+ * kmemcg_id. Setting the id after enabling static branching will
+ * guarantee no one starts accounting before all call sites are
+ * patched.
+ */
+ memcg->kmemcg_id = memcg_id;
+ memcg->kmem_acct_activated = true;
+ memcg->kmem_acct_active = true;
+out:
+ return err;
+}
+
+static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
+ unsigned long limit)
+{
+ int ret;
+
+ mutex_lock(&memcg_limit_mutex);
+ if (!memcg_kmem_is_active(memcg))
+ ret = memcg_activate_kmem(memcg, limit);
+ else
+ ret = page_counter_limit(&memcg->kmem, limit);
+ mutex_unlock(&memcg_limit_mutex);
+ return ret;
+}
+
+static int memcg_propagate_kmem(struct mem_cgroup *memcg)
+{
+ int ret = 0;
+ struct mem_cgroup *parent = parent_mem_cgroup(memcg);
+
+ if (!parent)
+ return 0;
+
+ mutex_lock(&memcg_limit_mutex);
+ /*
+ * If the parent cgroup is not kmem-active now, it cannot be activated
+ * after this point, because it has at least one child already.
+ */
+ if (memcg_kmem_is_active(parent))
+ ret = memcg_activate_kmem(memcg, PAGE_COUNTER_MAX);
+ mutex_unlock(&memcg_limit_mutex);
+ return ret;
+}
+#else
+static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
+ unsigned long limit)
+{
+ return -EINVAL;
+}
+#endif /* CONFIG_MEMCG_KMEM */
+
+/*
+ * The user of this function is...
+ * RES_LIMIT.
+ */
+static ssize_t mem_cgroup_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
+ unsigned long nr_pages;
+ int ret;
+
+ buf = strstrip(buf);
+ ret = page_counter_memparse(buf, "-1", &nr_pages);
+ if (ret)
+ return ret;
+
+ switch (MEMFILE_ATTR(of_cft(of)->private)) {
+ case RES_LIMIT:
+ if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
+ ret = -EINVAL;
+ break;
+ }
+ switch (MEMFILE_TYPE(of_cft(of)->private)) {
+ case _MEM:
+ ret = mem_cgroup_resize_limit(memcg, nr_pages);
+ break;
+ case _MEMSWAP:
+ ret = mem_cgroup_resize_memsw_limit(memcg, nr_pages);
+ break;
+ case _KMEM:
+ ret = memcg_update_kmem_limit(memcg, nr_pages);
+ break;
+ }
+ break;
+ case RES_SOFT_LIMIT:
+ memcg->soft_limit = nr_pages;
+ ret = 0;
+ break;
+ }
+ return ret ?: nbytes;
+}
+
+static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf,
+ size_t nbytes, loff_t off)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
+ struct page_counter *counter;
+
+ switch (MEMFILE_TYPE(of_cft(of)->private)) {
+ case _MEM:
+ counter = &memcg->memory;
+ break;
+ case _MEMSWAP:
+ counter = &memcg->memsw;
+ break;
+ case _KMEM:
+ counter = &memcg->kmem;
+ break;
+ default:
+ BUG();
+ }
+
+ switch (MEMFILE_ATTR(of_cft(of)->private)) {
+ case RES_MAX_USAGE:
+ page_counter_reset_watermark(counter);
+ break;
+ case RES_FAILCNT:
+ counter->failcnt = 0;
+ break;
+ default:
+ BUG();
+ }
+
+ return nbytes;
+}
+
+static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ return mem_cgroup_from_css(css)->move_charge_at_immigrate;
+}
+
+#ifdef CONFIG_MMU
+static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+ if (val & ~MOVE_MASK)
+ return -EINVAL;
+
+ /*
+ * No kind of locking is needed in here, because ->can_attach() will
+ * check this value once in the beginning of the process, and then carry
+ * on with stale data. This means that changes to this value will only
+ * affect task migrations starting after the change.
+ */
+ memcg->move_charge_at_immigrate = val;
+ return 0;
+}
+#else
+static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
+{
+ return -ENOSYS;
+}
+#endif
+
+#ifdef CONFIG_NUMA
+static int memcg_numa_stat_show(struct seq_file *m, void *v)
+{
+ struct numa_stat {
+ const char *name;
+ unsigned int lru_mask;
+ };
+
+ static const struct numa_stat stats[] = {
+ { "total", LRU_ALL },
+ { "file", LRU_ALL_FILE },
+ { "anon", LRU_ALL_ANON },
+ { "unevictable", BIT(LRU_UNEVICTABLE) },
+ };
+ const struct numa_stat *stat;
+ int nid;
+ unsigned long nr;
+ struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+
+ for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
+ nr = mem_cgroup_nr_lru_pages(memcg, stat->lru_mask);
+ seq_printf(m, "%s=%lu", stat->name, nr);
+ for_each_node_state(nid, N_MEMORY) {
+ nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
+ stat->lru_mask);
+ seq_printf(m, " N%d=%lu", nid, nr);
+ }
+ seq_putc(m, '\n');
+ }
+
+ for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
+ struct mem_cgroup *iter;
+
+ nr = 0;
+ for_each_mem_cgroup_tree(iter, memcg)
+ nr += mem_cgroup_nr_lru_pages(iter, stat->lru_mask);
+ seq_printf(m, "hierarchical_%s=%lu", stat->name, nr);
+ for_each_node_state(nid, N_MEMORY) {
+ nr = 0;
+ for_each_mem_cgroup_tree(iter, memcg)
+ nr += mem_cgroup_node_nr_lru_pages(
+ iter, nid, stat->lru_mask);
+ seq_printf(m, " N%d=%lu", nid, nr);
+ }
+ seq_putc(m, '\n');
+ }
+
+ return 0;
+}
+#endif /* CONFIG_NUMA */
+
+static int memcg_stat_show(struct seq_file *m, void *v)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+ unsigned long memory, memsw;
+ struct mem_cgroup *mi;
+ unsigned int i;
+
+ BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_stat_names) !=
+ MEM_CGROUP_STAT_NSTATS);
+ BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_events_names) !=
+ MEM_CGROUP_EVENTS_NSTATS);
+ BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS);
+
+ for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
+ if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
+ continue;
+ seq_printf(m, "%s %ld\n", mem_cgroup_stat_names[i],
+ mem_cgroup_read_stat(memcg, i) * PAGE_SIZE);
+ }
+
+ for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++)
+ seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i],
+ mem_cgroup_read_events(memcg, i));
+
+ for (i = 0; i < NR_LRU_LISTS; i++)
+ seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i],
+ mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE);
+
+ /* Hierarchical information */
+ memory = memsw = PAGE_COUNTER_MAX;
+ for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) {
+ memory = min(memory, mi->memory.limit);
+ memsw = min(memsw, mi->memsw.limit);
+ }
+ seq_printf(m, "hierarchical_memory_limit %llu\n",
+ (u64)memory * PAGE_SIZE);
+ if (do_swap_account)
+ seq_printf(m, "hierarchical_memsw_limit %llu\n",
+ (u64)memsw * PAGE_SIZE);
+
+ for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
+ long long val = 0;
+
+ if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
+ continue;
+ for_each_mem_cgroup_tree(mi, memcg)
+ val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE;
+ seq_printf(m, "total_%s %lld\n", mem_cgroup_stat_names[i], val);
+ }
+
+ for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
+ unsigned long long val = 0;
+
+ for_each_mem_cgroup_tree(mi, memcg)
+ val += mem_cgroup_read_events(mi, i);
+ seq_printf(m, "total_%s %llu\n",
+ mem_cgroup_events_names[i], val);
+ }
+
+ for (i = 0; i < NR_LRU_LISTS; i++) {
+ unsigned long long val = 0;
+
+ for_each_mem_cgroup_tree(mi, memcg)
+ val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE;
+ seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val);
+ }
+
+#ifdef CONFIG_DEBUG_VM
+ {
+ int nid, zid;
+ struct mem_cgroup_per_zone *mz;
+ struct zone_reclaim_stat *rstat;
+ unsigned long recent_rotated[2] = {0, 0};
+ unsigned long recent_scanned[2] = {0, 0};
+
+ for_each_online_node(nid)
+ for (zid = 0; zid < MAX_NR_ZONES; zid++) {
+ mz = &memcg->nodeinfo[nid]->zoneinfo[zid];
+ rstat = &mz->lruvec.reclaim_stat;
+
+ recent_rotated[0] += rstat->recent_rotated[0];
+ recent_rotated[1] += rstat->recent_rotated[1];
+ recent_scanned[0] += rstat->recent_scanned[0];
+ recent_scanned[1] += rstat->recent_scanned[1];
+ }
+ seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]);
+ seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]);
+ seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]);
+ seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]);
+ }
+#endif
+
+ return 0;
+}
+
+static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+ return mem_cgroup_swappiness(memcg);
+}
+
+static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+ if (val > 100)
+ return -EINVAL;
+
+ if (css->parent)
+ memcg->swappiness = val;
+ else
+ vm_swappiness = val;
+
+ return 0;
+}
+
+static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
+{
+ struct mem_cgroup_threshold_ary *t;
+ unsigned long usage;
+ int i;
+
+ rcu_read_lock();
+ if (!swap)
+ t = rcu_dereference(memcg->thresholds.primary);
+ else
+ t = rcu_dereference(memcg->memsw_thresholds.primary);
+
+ if (!t)
+ goto unlock;
+
+ usage = mem_cgroup_usage(memcg, swap);
+
+ /*
+ * current_threshold points to threshold just below or equal to usage.
+ * If it's not true, a threshold was crossed after last
+ * call of __mem_cgroup_threshold().
+ */
+ i = t->current_threshold;
+
+ /*
+ * Iterate backward over array of thresholds starting from
+ * current_threshold and check if a threshold is crossed.
+ * If none of thresholds below usage is crossed, we read
+ * only one element of the array here.
+ */
+ for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--)
+ eventfd_signal(t->entries[i].eventfd, 1);
+
+ /* i = current_threshold + 1 */
+ i++;
+
+ /*
+ * Iterate forward over array of thresholds starting from
+ * current_threshold+1 and check if a threshold is crossed.
+ * If none of thresholds above usage is crossed, we read
+ * only one element of the array here.
+ */
+ for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++)
+ eventfd_signal(t->entries[i].eventfd, 1);
+
+ /* Update current_threshold */
+ t->current_threshold = i - 1;
+unlock:
+ rcu_read_unlock();
+}
+
+static void mem_cgroup_threshold(struct mem_cgroup *memcg)
+{
+ while (memcg) {
+ __mem_cgroup_threshold(memcg, false);
+ if (do_swap_account)
+ __mem_cgroup_threshold(memcg, true);
+
+ memcg = parent_mem_cgroup(memcg);
+ }
+}
+
+static int compare_thresholds(const void *a, const void *b)
+{
+ const struct mem_cgroup_threshold *_a = a;
+ const struct mem_cgroup_threshold *_b = b;
+
+ if (_a->threshold > _b->threshold)
+ return 1;
+
+ if (_a->threshold < _b->threshold)
+ return -1;
+
+ return 0;
+}
+
+static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup_eventfd_list *ev;
+
+ spin_lock(&memcg_oom_lock);
+
+ list_for_each_entry(ev, &memcg->oom_notify, list)
+ eventfd_signal(ev->eventfd, 1);
+
+ spin_unlock(&memcg_oom_lock);
+ return 0;
+}
+
+static void mem_cgroup_oom_notify(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter;
+
+ for_each_mem_cgroup_tree(iter, memcg)
+ mem_cgroup_oom_notify_cb(iter);
+}
+
+static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, const char *args, enum res_type type)
+{
+ struct mem_cgroup_thresholds *thresholds;
+ struct mem_cgroup_threshold_ary *new;
+ unsigned long threshold;
+ unsigned long usage;
+ int i, size, ret;
+
+ ret = page_counter_memparse(args, "-1", &threshold);
+ if (ret)
+ return ret;
+
+ mutex_lock(&memcg->thresholds_lock);
+
+ if (type == _MEM) {
+ thresholds = &memcg->thresholds;
+ usage = mem_cgroup_usage(memcg, false);
+ } else if (type == _MEMSWAP) {
+ thresholds = &memcg->memsw_thresholds;
+ usage = mem_cgroup_usage(memcg, true);
+ } else
+ BUG();
+
+ /* Check if a threshold crossed before adding a new one */
+ if (thresholds->primary)
+ __mem_cgroup_threshold(memcg, type == _MEMSWAP);
+
+ size = thresholds->primary ? thresholds->primary->size + 1 : 1;
+
+ /* Allocate memory for new array of thresholds */
+ new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold),
+ GFP_KERNEL);
+ if (!new) {
+ ret = -ENOMEM;
+ goto unlock;
+ }
+ new->size = size;
+
+ /* Copy thresholds (if any) to new array */
+ if (thresholds->primary) {
+ memcpy(new->entries, thresholds->primary->entries, (size - 1) *
+ sizeof(struct mem_cgroup_threshold));
+ }
+
+ /* Add new threshold */
+ new->entries[size - 1].eventfd = eventfd;
+ new->entries[size - 1].threshold = threshold;
+
+ /* Sort thresholds. Registering of new threshold isn't time-critical */
+ sort(new->entries, size, sizeof(struct mem_cgroup_threshold),
+ compare_thresholds, NULL);
+
+ /* Find current threshold */
+ new->current_threshold = -1;
+ for (i = 0; i < size; i++) {
+ if (new->entries[i].threshold <= usage) {
+ /*
+ * new->current_threshold will not be used until
+ * rcu_assign_pointer(), so it's safe to increment
+ * it here.
+ */
+ ++new->current_threshold;
+ } else
+ break;
+ }
+
+ /* Free old spare buffer and save old primary buffer as spare */
+ kfree(thresholds->spare);
+ thresholds->spare = thresholds->primary;
+
+ rcu_assign_pointer(thresholds->primary, new);
+
+ /* To be sure that nobody uses thresholds */
+ synchronize_rcu();
+
+unlock:
+ mutex_unlock(&memcg->thresholds_lock);
+
+ return ret;
+}
+
+static int mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, const char *args)
+{
+ return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEM);
+}
+
+static int memsw_cgroup_usage_register_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, const char *args)
+{
+ return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEMSWAP);
+}
+
+static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, enum res_type type)
+{
+ struct mem_cgroup_thresholds *thresholds;
+ struct mem_cgroup_threshold_ary *new;
+ unsigned long usage;
+ int i, j, size;
+
+ mutex_lock(&memcg->thresholds_lock);
+
+ if (type == _MEM) {
+ thresholds = &memcg->thresholds;
+ usage = mem_cgroup_usage(memcg, false);
+ } else if (type == _MEMSWAP) {
+ thresholds = &memcg->memsw_thresholds;
+ usage = mem_cgroup_usage(memcg, true);
+ } else
+ BUG();
+
+ if (!thresholds->primary)
+ goto unlock;
+
+ /* Check if a threshold crossed before removing */
+ __mem_cgroup_threshold(memcg, type == _MEMSWAP);
+
+ /* Calculate new number of threshold */
+ size = 0;
+ for (i = 0; i < thresholds->primary->size; i++) {
+ if (thresholds->primary->entries[i].eventfd != eventfd)
+ size++;
+ }
+
+ new = thresholds->spare;
+
+ /* Set thresholds array to NULL if we don't have thresholds */
+ if (!size) {
+ kfree(new);
+ new = NULL;
+ goto swap_buffers;
+ }
+
+ new->size = size;
+
+ /* Copy thresholds and find current threshold */
+ new->current_threshold = -1;
+ for (i = 0, j = 0; i < thresholds->primary->size; i++) {
+ if (thresholds->primary->entries[i].eventfd == eventfd)
+ continue;
+
+ new->entries[j] = thresholds->primary->entries[i];
+ if (new->entries[j].threshold <= usage) {
+ /*
+ * new->current_threshold will not be used
+ * until rcu_assign_pointer(), so it's safe to increment
+ * it here.
+ */
+ ++new->current_threshold;
+ }
+ j++;
+ }
+
+swap_buffers:
+ /* Swap primary and spare array */
+ thresholds->spare = thresholds->primary;
+ /* If all events are unregistered, free the spare array */
+ if (!new) {
+ kfree(thresholds->spare);
+ thresholds->spare = NULL;
+ }
+
+ rcu_assign_pointer(thresholds->primary, new);
+
+ /* To be sure that nobody uses thresholds */
+ synchronize_rcu();
+unlock:
+ mutex_unlock(&memcg->thresholds_lock);
+}
+
+static void mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd)
+{
+ return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEM);
+}
+
+static void memsw_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd)
+{
+ return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEMSWAP);
+}
+
+static int mem_cgroup_oom_register_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, const char *args)
+{
+ struct mem_cgroup_eventfd_list *event;
+
+ event = kmalloc(sizeof(*event), GFP_KERNEL);
+ if (!event)
+ return -ENOMEM;
+
+ spin_lock(&memcg_oom_lock);
+
+ event->eventfd = eventfd;
+ list_add(&event->list, &memcg->oom_notify);
+
+ /* already in OOM ? */
+ if (atomic_read(&memcg->under_oom))
+ eventfd_signal(eventfd, 1);
+ spin_unlock(&memcg_oom_lock);
+
+ return 0;
+}
+
+static void mem_cgroup_oom_unregister_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd)
+{
+ struct mem_cgroup_eventfd_list *ev, *tmp;
+
+ spin_lock(&memcg_oom_lock);
+
+ list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) {
+ if (ev->eventfd == eventfd) {
+ list_del(&ev->list);
+ kfree(ev);
+ }
+ }
+
+ spin_unlock(&memcg_oom_lock);
+}
+
+static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(sf));
+
+ seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable);
+ seq_printf(sf, "under_oom %d\n", (bool)atomic_read(&memcg->under_oom));
+ return 0;
+}
+
+static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+ /* cannot set to root cgroup and only 0 and 1 are allowed */
+ if (!css->parent || !((val == 0) || (val == 1)))
+ return -EINVAL;
+
+ memcg->oom_kill_disable = val;
+ if (!val)
+ memcg_oom_recover(memcg);
+
+ return 0;
+}
+
+#ifdef CONFIG_MEMCG_KMEM
+static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
+{
+ int ret;
+
+ ret = memcg_propagate_kmem(memcg);
+ if (ret)
+ return ret;
+
+ return mem_cgroup_sockets_init(memcg, ss);
+}
+
+static void memcg_deactivate_kmem(struct mem_cgroup *memcg)
+{
+ struct cgroup_subsys_state *css;
+ struct mem_cgroup *parent, *child;
+ int kmemcg_id;
+
+ if (!memcg->kmem_acct_active)
+ return;
+
+ /*
+ * Clear the 'active' flag before clearing memcg_caches arrays entries.
+ * Since we take the slab_mutex in memcg_deactivate_kmem_caches(), it
+ * guarantees no cache will be created for this cgroup after we are
+ * done (see memcg_create_kmem_cache()).
+ */
+ memcg->kmem_acct_active = false;
+
+ memcg_deactivate_kmem_caches(memcg);
+
+ kmemcg_id = memcg->kmemcg_id;
+ BUG_ON(kmemcg_id < 0);
+
+ parent = parent_mem_cgroup(memcg);
+ if (!parent)
+ parent = root_mem_cgroup;
+
+ /*
+ * Change kmemcg_id of this cgroup and all its descendants to the
+ * parent's id, and then move all entries from this cgroup's list_lrus
+ * to ones of the parent. After we have finished, all list_lrus
+ * corresponding to this cgroup are guaranteed to remain empty. The
+ * ordering is imposed by list_lru_node->lock taken by
+ * memcg_drain_all_list_lrus().
+ */
+ css_for_each_descendant_pre(css, &memcg->css) {
+ child = mem_cgroup_from_css(css);
+ BUG_ON(child->kmemcg_id != kmemcg_id);
+ child->kmemcg_id = parent->kmemcg_id;
+ if (!memcg->use_hierarchy)
+ break;
+ }
+ memcg_drain_all_list_lrus(kmemcg_id, parent->kmemcg_id);
+
+ memcg_free_cache_id(kmemcg_id);
+}
+
+static void memcg_destroy_kmem(struct mem_cgroup *memcg)
+{
+ if (memcg->kmem_acct_activated) {
+ memcg_destroy_kmem_caches(memcg);
+ static_key_slow_dec(&memcg_kmem_enabled_key);
+ WARN_ON(page_counter_read(&memcg->kmem));
+ }
+ mem_cgroup_sockets_destroy(memcg);
+}
+#else
+static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
+{
+ return 0;
+}
+
+static void memcg_deactivate_kmem(struct mem_cgroup *memcg)
+{
+}
+
+static void memcg_destroy_kmem(struct mem_cgroup *memcg)
+{
+}
+#endif
+
+/*
+ * DO NOT USE IN NEW FILES.
+ *
+ * "cgroup.event_control" implementation.
+ *
+ * This is way over-engineered. It tries to support fully configurable
+ * events for each user. Such level of flexibility is completely
+ * unnecessary especially in the light of the planned unified hierarchy.
+ *
+ * Please deprecate this and replace with something simpler if at all
+ * possible.
+ */
+
+/*
+ * Unregister event and free resources.
+ *
+ * Gets called from workqueue.
+ */
+static void memcg_event_remove(struct work_struct *work)
+{
+ struct mem_cgroup_event *event =
+ container_of(work, struct mem_cgroup_event, remove);
+ struct mem_cgroup *memcg = event->memcg;
+
+ remove_wait_queue(event->wqh, &event->wait);
+
+ event->unregister_event(memcg, event->eventfd);
+
+ /* Notify userspace the event is going away. */
+ eventfd_signal(event->eventfd, 1);
+
+ eventfd_ctx_put(event->eventfd);
+ kfree(event);
+ css_put(&memcg->css);
+}
+
+/*
+ * Gets called on POLLHUP on eventfd when user closes it.
+ *
+ * Called with wqh->lock held and interrupts disabled.
+ */
+static int memcg_event_wake(wait_queue_t *wait, unsigned mode,
+ int sync, void *key)
+{
+ struct mem_cgroup_event *event =
+ container_of(wait, struct mem_cgroup_event, wait);
+ struct mem_cgroup *memcg = event->memcg;
+ unsigned long flags = (unsigned long)key;
+
+ if (flags & POLLHUP) {
+ /*
+ * If the event has been detached at cgroup removal, we
+ * can simply return knowing the other side will cleanup
+ * for us.
+ *
+ * We can't race against event freeing since the other
+ * side will require wqh->lock via remove_wait_queue(),
+ * which we hold.
+ */
+ spin_lock(&memcg->event_list_lock);
+ if (!list_empty(&event->list)) {
+ list_del_init(&event->list);
+ /*
+ * We are in atomic context, but cgroup_event_remove()
+ * may sleep, so we have to call it in workqueue.
+ */
+ schedule_work(&event->remove);
+ }
+ spin_unlock(&memcg->event_list_lock);
+ }
+
+ return 0;
+}
+
+static void memcg_event_ptable_queue_proc(struct file *file,
+ wait_queue_head_t *wqh, poll_table *pt)
+{
+ struct mem_cgroup_event *event =
+ container_of(pt, struct mem_cgroup_event, pt);
+
+ event->wqh = wqh;
+ add_wait_queue(wqh, &event->wait);
+}
+
+/*
+ * DO NOT USE IN NEW FILES.
+ *
+ * Parse input and register new cgroup event handler.
+ *
+ * Input must be in format '<event_fd> <control_fd> <args>'.
+ * Interpretation of args is defined by control file implementation.
+ */
+static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct cgroup_subsys_state *css = of_css(of);
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct mem_cgroup_event *event;
+ struct cgroup_subsys_state *cfile_css;
+ unsigned int efd, cfd;
+ struct fd efile;
+ struct fd cfile;
+ const char *name;
+ char *endp;
+ int ret;
+
+ buf = strstrip(buf);
+
+ efd = simple_strtoul(buf, &endp, 10);
+ if (*endp != ' ')
+ return -EINVAL;
+ buf = endp + 1;
+
+ cfd = simple_strtoul(buf, &endp, 10);
+ if ((*endp != ' ') && (*endp != '\0'))
+ return -EINVAL;
+ buf = endp + 1;
+
+ event = kzalloc(sizeof(*event), GFP_KERNEL);
+ if (!event)
+ return -ENOMEM;
+
+ event->memcg = memcg;
+ INIT_LIST_HEAD(&event->list);
+ init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc);
+ init_waitqueue_func_entry(&event->wait, memcg_event_wake);
+ INIT_WORK(&event->remove, memcg_event_remove);
+
+ efile = fdget(efd);
+ if (!efile.file) {
+ ret = -EBADF;
+ goto out_kfree;
+ }
+
+ event->eventfd = eventfd_ctx_fileget(efile.file);
+ if (IS_ERR(event->eventfd)) {
+ ret = PTR_ERR(event->eventfd);
+ goto out_put_efile;
+ }
+
+ cfile = fdget(cfd);
+ if (!cfile.file) {
+ ret = -EBADF;
+ goto out_put_eventfd;
+ }
+
+ /* the process need read permission on control file */
+ /* AV: shouldn't we check that it's been opened for read instead? */
+ ret = inode_permission(file_inode(cfile.file), MAY_READ);
+ if (ret < 0)
+ goto out_put_cfile;
+
+ /*
+ * Determine the event callbacks and set them in @event. This used
+ * to be done via struct cftype but cgroup core no longer knows
+ * about these events. The following is crude but the whole thing
+ * is for compatibility anyway.
+ *
+ * DO NOT ADD NEW FILES.
+ */
+ name = cfile.file->f_path.dentry->d_name.name;
+
+ if (!strcmp(name, "memory.usage_in_bytes")) {
+ event->register_event = mem_cgroup_usage_register_event;
+ event->unregister_event = mem_cgroup_usage_unregister_event;
+ } else if (!strcmp(name, "memory.oom_control")) {
+ event->register_event = mem_cgroup_oom_register_event;
+ event->unregister_event = mem_cgroup_oom_unregister_event;
+ } else if (!strcmp(name, "memory.pressure_level")) {
+ event->register_event = vmpressure_register_event;
+ event->unregister_event = vmpressure_unregister_event;
+ } else if (!strcmp(name, "memory.memsw.usage_in_bytes")) {
+ event->register_event = memsw_cgroup_usage_register_event;
+ event->unregister_event = memsw_cgroup_usage_unregister_event;
+ } else {
+ ret = -EINVAL;
+ goto out_put_cfile;
+ }
+
+ /*
+ * Verify @cfile should belong to @css. Also, remaining events are
+ * automatically removed on cgroup destruction but the removal is
+ * asynchronous, so take an extra ref on @css.
+ */
+ cfile_css = css_tryget_online_from_dir(cfile.file->f_path.dentry->d_parent,
+ &memory_cgrp_subsys);
+ ret = -EINVAL;
+ if (IS_ERR(cfile_css))
+ goto out_put_cfile;
+ if (cfile_css != css) {
+ css_put(cfile_css);
+ goto out_put_cfile;
+ }
+
+ ret = event->register_event(memcg, event->eventfd, buf);
+ if (ret)
+ goto out_put_css;
+
+ efile.file->f_op->poll(efile.file, &event->pt);
+
+ spin_lock(&memcg->event_list_lock);
+ list_add(&event->list, &memcg->event_list);
+ spin_unlock(&memcg->event_list_lock);
+
+ fdput(cfile);
+ fdput(efile);
+
+ return nbytes;
+
+out_put_css:
+ css_put(css);
+out_put_cfile:
+ fdput(cfile);
+out_put_eventfd:
+ eventfd_ctx_put(event->eventfd);
+out_put_efile:
+ fdput(efile);
+out_kfree:
+ kfree(event);
+
+ return ret;
+}
+
+static struct cftype mem_cgroup_legacy_files[] = {
+ {
+ .name = "usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "max_usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
+ .write = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "limit_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
+ .write = mem_cgroup_write,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "soft_limit_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
+ .write = mem_cgroup_write,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "failcnt",
+ .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
+ .write = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "stat",
+ .seq_show = memcg_stat_show,
+ },
+ {
+ .name = "force_empty",
+ .write = mem_cgroup_force_empty_write,
+ },
+ {
+ .name = "use_hierarchy",
+ .write_u64 = mem_cgroup_hierarchy_write,
+ .read_u64 = mem_cgroup_hierarchy_read,
+ },
+ {
+ .name = "cgroup.event_control", /* XXX: for compat */
+ .write = memcg_write_event_control,
+ .flags = CFTYPE_NO_PREFIX,
+ .mode = S_IWUGO,
+ },
+ {
+ .name = "swappiness",
+ .read_u64 = mem_cgroup_swappiness_read,
+ .write_u64 = mem_cgroup_swappiness_write,
+ },
+ {
+ .name = "move_charge_at_immigrate",
+ .read_u64 = mem_cgroup_move_charge_read,
+ .write_u64 = mem_cgroup_move_charge_write,
+ },
+ {
+ .name = "oom_control",
+ .seq_show = mem_cgroup_oom_control_read,
+ .write_u64 = mem_cgroup_oom_control_write,
+ .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
+ },
+ {
+ .name = "pressure_level",
+ },
+#ifdef CONFIG_NUMA
+ {
+ .name = "numa_stat",
+ .seq_show = memcg_numa_stat_show,
+ },
+#endif
+#ifdef CONFIG_MEMCG_KMEM
+ {
+ .name = "kmem.limit_in_bytes",
+ .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT),
+ .write = mem_cgroup_write,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "kmem.usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE),
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "kmem.failcnt",
+ .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT),
+ .write = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "kmem.max_usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE),
+ .write = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+#ifdef CONFIG_SLABINFO
+ {
+ .name = "kmem.slabinfo",
+ .seq_start = slab_start,
+ .seq_next = slab_next,
+ .seq_stop = slab_stop,
+ .seq_show = memcg_slab_show,
+ },
+#endif
+#endif
+ { }, /* terminate */
+};
+
+static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
+{
+ struct mem_cgroup_per_node *pn;
+ struct mem_cgroup_per_zone *mz;
+ int zone, tmp = node;
+ /*
+ * This routine is called against possible nodes.
+ * But it's BUG to call kmalloc() against offline node.
+ *
+ * TODO: this routine can waste much memory for nodes which will
+ * never be onlined. It's better to use memory hotplug callback
+ * function.
+ */
+ if (!node_state(node, N_NORMAL_MEMORY))
+ tmp = -1;
+ pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
+ if (!pn)
+ return 1;
+
+ for (zone = 0; zone < MAX_NR_ZONES; zone++) {
+ mz = &pn->zoneinfo[zone];
+ lruvec_init(&mz->lruvec);
+ mz->usage_in_excess = 0;
+ mz->on_tree = false;
+ mz->memcg = memcg;
+ }
+ memcg->nodeinfo[node] = pn;
+ return 0;
+}
+
+static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
+{
+ kfree(memcg->nodeinfo[node]);
+}
+
+static struct mem_cgroup *mem_cgroup_alloc(void)
+{
+ struct mem_cgroup *memcg;
+ size_t size;
+
+ size = sizeof(struct mem_cgroup);
+ size += nr_node_ids * sizeof(struct mem_cgroup_per_node *);
+
+ memcg = kzalloc(size, GFP_KERNEL);
+ if (!memcg)
+ return NULL;
+
+ memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
+ if (!memcg->stat)
+ goto out_free;
+ spin_lock_init(&memcg->pcp_counter_lock);
+ return memcg;
+
+out_free:
+ kfree(memcg);
+ return NULL;
+}
+
+/*
+ * At destroying mem_cgroup, references from swap_cgroup can remain.
+ * (scanning all at force_empty is too costly...)
+ *
+ * Instead of clearing all references at force_empty, we remember
+ * the number of reference from swap_cgroup and free mem_cgroup when
+ * it goes down to 0.
+ *
+ * Removal of cgroup itself succeeds regardless of refs from swap.
+ */
+
+static void __mem_cgroup_free(struct mem_cgroup *memcg)
+{
+ int node;
+
+ mem_cgroup_remove_from_trees(memcg);
+
+ for_each_node(node)
+ free_mem_cgroup_per_zone_info(memcg, node);
+
+ free_percpu(memcg->stat);
+ kfree(memcg);
+}
+
+/*
+ * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
+ */
+struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
+{
+ if (!memcg->memory.parent)
+ return NULL;
+ return mem_cgroup_from_counter(memcg->memory.parent, memory);
+}
+EXPORT_SYMBOL(parent_mem_cgroup);
+
+static struct cgroup_subsys_state * __ref
+mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
+{
+ struct mem_cgroup *memcg;
+ long error = -ENOMEM;
+ int node;
+
+ memcg = mem_cgroup_alloc();
+ if (!memcg)
+ return ERR_PTR(error);
+
+ for_each_node(node)
+ if (alloc_mem_cgroup_per_zone_info(memcg, node))
+ goto free_out;
+
+ /* root ? */
+ if (parent_css == NULL) {
+ root_mem_cgroup = memcg;
+ page_counter_init(&memcg->memory, NULL);
+ memcg->high = PAGE_COUNTER_MAX;
+ memcg->soft_limit = PAGE_COUNTER_MAX;
+ page_counter_init(&memcg->memsw, NULL);
+ page_counter_init(&memcg->kmem, NULL);
+ }
+
+ memcg->last_scanned_node = MAX_NUMNODES;
+ INIT_LIST_HEAD(&memcg->oom_notify);
+ memcg->move_charge_at_immigrate = 0;
+ mutex_init(&memcg->thresholds_lock);
+ spin_lock_init(&memcg->move_lock);
+ vmpressure_init(&memcg->vmpressure);
+ INIT_LIST_HEAD(&memcg->event_list);
+ spin_lock_init(&memcg->event_list_lock);
+#ifdef CONFIG_MEMCG_KMEM
+ memcg->kmemcg_id = -1;
+#endif
+
+ return &memcg->css;
+
+free_out:
+ __mem_cgroup_free(memcg);
+ return ERR_PTR(error);
+}
+
+static int
+mem_cgroup_css_online(struct cgroup_subsys_state *css)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct mem_cgroup *parent = mem_cgroup_from_css(css->parent);
+ int ret;
+
+ if (css->id > MEM_CGROUP_ID_MAX)
+ return -ENOSPC;
+
+ if (!parent)
+ return 0;
+
+ mutex_lock(&memcg_create_mutex);
+
+ memcg->use_hierarchy = parent->use_hierarchy;
+ memcg->oom_kill_disable = parent->oom_kill_disable;
+ memcg->swappiness = mem_cgroup_swappiness(parent);
+
+ if (parent->use_hierarchy) {
+ page_counter_init(&memcg->memory, &parent->memory);
+ memcg->high = PAGE_COUNTER_MAX;
+ memcg->soft_limit = PAGE_COUNTER_MAX;
+ page_counter_init(&memcg->memsw, &parent->memsw);
+ page_counter_init(&memcg->kmem, &parent->kmem);
+
+ /*
+ * No need to take a reference to the parent because cgroup
+ * core guarantees its existence.
+ */
+ } else {
+ page_counter_init(&memcg->memory, NULL);
+ memcg->high = PAGE_COUNTER_MAX;
+ memcg->soft_limit = PAGE_COUNTER_MAX;
+ page_counter_init(&memcg->memsw, NULL);
+ page_counter_init(&memcg->kmem, NULL);
+ /*
+ * Deeper hierachy with use_hierarchy == false doesn't make
+ * much sense so let cgroup subsystem know about this
+ * unfortunate state in our controller.
+ */
+ if (parent != root_mem_cgroup)
+ memory_cgrp_subsys.broken_hierarchy = true;
+ }
+ mutex_unlock(&memcg_create_mutex);
+
+ ret = memcg_init_kmem(memcg, &memory_cgrp_subsys);
+ if (ret)
+ return ret;
+
+ /*
+ * Make sure the memcg is initialized: mem_cgroup_iter()
+ * orders reading memcg->initialized against its callers
+ * reading the memcg members.
+ */
+ smp_store_release(&memcg->initialized, 1);
+
+ return 0;
+}
+
+static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct mem_cgroup_event *event, *tmp;
+
+ /*
+ * Unregister events and notify userspace.
+ * Notify userspace about cgroup removing only after rmdir of cgroup
+ * directory to avoid race between userspace and kernelspace.
+ */
+ spin_lock(&memcg->event_list_lock);
+ list_for_each_entry_safe(event, tmp, &memcg->event_list, list) {
+ list_del_init(&event->list);
+ schedule_work(&event->remove);
+ }
+ spin_unlock(&memcg->event_list_lock);
+
+ vmpressure_cleanup(&memcg->vmpressure);
+
+ memcg_deactivate_kmem(memcg);
+}
+
+static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+ memcg_destroy_kmem(memcg);
+ __mem_cgroup_free(memcg);
+}
+
+/**
+ * mem_cgroup_css_reset - reset the states of a mem_cgroup
+ * @css: the target css
+ *
+ * Reset the states of the mem_cgroup associated with @css. This is
+ * invoked when the userland requests disabling on the default hierarchy
+ * but the memcg is pinned through dependency. The memcg should stop
+ * applying policies and should revert to the vanilla state as it may be
+ * made visible again.
+ *
+ * The current implementation only resets the essential configurations.
+ * This needs to be expanded to cover all the visible parts.
+ */
+static void mem_cgroup_css_reset(struct cgroup_subsys_state *css)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+ mem_cgroup_resize_limit(memcg, PAGE_COUNTER_MAX);
+ mem_cgroup_resize_memsw_limit(memcg, PAGE_COUNTER_MAX);
+ memcg_update_kmem_limit(memcg, PAGE_COUNTER_MAX);
+ memcg->low = 0;
+ memcg->high = PAGE_COUNTER_MAX;
+ memcg->soft_limit = PAGE_COUNTER_MAX;
+}
+
+#ifdef CONFIG_MMU
+/* Handlers for move charge at task migration. */
+static int mem_cgroup_do_precharge(unsigned long count)
+{
+ int ret;
+
+ /* Try a single bulk charge without reclaim first */
+ ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_WAIT, count);
+ if (!ret) {
+ mc.precharge += count;
+ return ret;
+ }
+ if (ret == -EINTR) {
+ cancel_charge(root_mem_cgroup, count);
+ return ret;
+ }
+
+ /* Try charges one by one with reclaim */
+ while (count--) {
+ ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_NORETRY, 1);
+ /*
+ * In case of failure, any residual charges against
+ * mc.to will be dropped by mem_cgroup_clear_mc()
+ * later on. However, cancel any charges that are
+ * bypassed to root right away or they'll be lost.
+ */
+ if (ret == -EINTR)
+ cancel_charge(root_mem_cgroup, 1);
+ if (ret)
+ return ret;
+ mc.precharge++;
+ cond_resched();
+ }
+ return 0;
+}
+
+/**
+ * get_mctgt_type - get target type of moving charge
+ * @vma: the vma the pte to be checked belongs
+ * @addr: the address corresponding to the pte to be checked
+ * @ptent: the pte to be checked
+ * @target: the pointer the target page or swap ent will be stored(can be NULL)
+ *
+ * Returns
+ * 0(MC_TARGET_NONE): if the pte is not a target for move charge.
+ * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
+ * move charge. if @target is not NULL, the page is stored in target->page
+ * with extra refcnt got(Callers should handle it).
+ * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
+ * target for charge migration. if @target is not NULL, the entry is stored
+ * in target->ent.
+ *
+ * Called with pte lock held.
+ */
+union mc_target {
+ struct page *page;
+ swp_entry_t ent;
+};
+
+enum mc_target_type {
+ MC_TARGET_NONE = 0,
+ MC_TARGET_PAGE,
+ MC_TARGET_SWAP,
+};
+
+static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
+ unsigned long addr, pte_t ptent)
+{
+ struct page *page = vm_normal_page(vma, addr, ptent);
+
+ if (!page || !page_mapped(page))
+ return NULL;
+ if (PageAnon(page)) {
+ if (!(mc.flags & MOVE_ANON))
+ return NULL;
+ } else {
+ if (!(mc.flags & MOVE_FILE))
+ return NULL;
+ }
+ if (!get_page_unless_zero(page))
+ return NULL;
+
+ return page;
+}
+
+#ifdef CONFIG_SWAP
+static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
+ unsigned long addr, pte_t ptent, swp_entry_t *entry)
+{
+ struct page *page = NULL;
+ swp_entry_t ent = pte_to_swp_entry(ptent);
+
+ if (!(mc.flags & MOVE_ANON) || non_swap_entry(ent))
+ return NULL;
+ /*
+ * Because lookup_swap_cache() updates some statistics counter,
+ * we call find_get_page() with swapper_space directly.
+ */
+ page = find_get_page(swap_address_space(ent), ent.val);
+ if (do_swap_account)
+ entry->val = ent.val;
+
+ return page;
+}
+#else
+static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
+ unsigned long addr, pte_t ptent, swp_entry_t *entry)
+{
+ return NULL;
+}
+#endif
+
+static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
+ unsigned long addr, pte_t ptent, swp_entry_t *entry)
+{
+ struct page *page = NULL;
+ struct address_space *mapping;
+ pgoff_t pgoff;
+
+ if (!vma->vm_file) /* anonymous vma */
+ return NULL;
+ if (!(mc.flags & MOVE_FILE))
+ return NULL;
+
+ mapping = vma->vm_file->f_mapping;
+ pgoff = linear_page_index(vma, addr);
+
+ /* page is moved even if it's not RSS of this task(page-faulted). */
+#ifdef CONFIG_SWAP
+ /* shmem/tmpfs may report page out on swap: account for that too. */
+ if (shmem_mapping(mapping)) {
+ page = find_get_entry(mapping, pgoff);
+ if (radix_tree_exceptional_entry(page)) {
+ swp_entry_t swp = radix_to_swp_entry(page);
+ if (do_swap_account)
+ *entry = swp;
+ page = find_get_page(swap_address_space(swp), swp.val);
+ }
+ } else
+ page = find_get_page(mapping, pgoff);
+#else
+ page = find_get_page(mapping, pgoff);
+#endif
+ return page;
+}
+
+/**
+ * mem_cgroup_move_account - move account of the page
+ * @page: the page
+ * @nr_pages: number of regular pages (>1 for huge pages)
+ * @from: mem_cgroup which the page is moved from.
+ * @to: mem_cgroup which the page is moved to. @from != @to.
+ *
+ * The caller must confirm following.
+ * - page is not on LRU (isolate_page() is useful.)
+ * - compound_lock is held when nr_pages > 1
+ *
+ * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
+ * from old cgroup.
+ */
+static int mem_cgroup_move_account(struct page *page,
+ unsigned int nr_pages,
+ struct mem_cgroup *from,
+ struct mem_cgroup *to)
+{
+ unsigned long flags;
+ int ret;
+
+ VM_BUG_ON(from == to);
+ VM_BUG_ON_PAGE(PageLRU(page), page);
+ /*
+ * The page is isolated from LRU. So, collapse function
+ * will not handle this page. But page splitting can happen.
+ * Do this check under compound_page_lock(). The caller should
+ * hold it.
+ */
+ ret = -EBUSY;
+ if (nr_pages > 1 && !PageTransHuge(page))
+ goto out;
+
+ /*
+ * Prevent mem_cgroup_migrate() from looking at page->mem_cgroup
+ * of its source page while we change it: page migration takes
+ * both pages off the LRU, but page cache replacement doesn't.
+ */
+ if (!trylock_page(page))
+ goto out;
+
+ ret = -EINVAL;
+ if (page->mem_cgroup != from)
+ goto out_unlock;
+
+ spin_lock_irqsave(&from->move_lock, flags);
+
+ if (!PageAnon(page) && page_mapped(page)) {
+ __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED],
+ nr_pages);
+ __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED],
+ nr_pages);
+ }
+
+ if (PageWriteback(page)) {
+ __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_WRITEBACK],
+ nr_pages);
+ __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_WRITEBACK],
+ nr_pages);
+ }
+
+ /*
+ * It is safe to change page->mem_cgroup here because the page
+ * is referenced, charged, and isolated - we can't race with
+ * uncharging, charging, migration, or LRU putback.
+ */
+
+ /* caller should have done css_get */
+ page->mem_cgroup = to;
+ spin_unlock_irqrestore(&from->move_lock, flags);
+
+ ret = 0;
+
+ local_lock_irq(event_lock);
+ mem_cgroup_charge_statistics(to, page, nr_pages);
+ memcg_check_events(to, page);
+ mem_cgroup_charge_statistics(from, page, -nr_pages);
+ memcg_check_events(from, page);
+ local_unlock_irq(event_lock);
+out_unlock:
+ unlock_page(page);
+out:
+ return ret;
+}
+
+static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
+ unsigned long addr, pte_t ptent, union mc_target *target)
+{
+ struct page *page = NULL;
+ enum mc_target_type ret = MC_TARGET_NONE;
+ swp_entry_t ent = { .val = 0 };
+
+ if (pte_present(ptent))
+ page = mc_handle_present_pte(vma, addr, ptent);
+ else if (is_swap_pte(ptent))
+ page = mc_handle_swap_pte(vma, addr, ptent, &ent);
+ else if (pte_none(ptent))
+ page = mc_handle_file_pte(vma, addr, ptent, &ent);
+
+ if (!page && !ent.val)
+ return ret;
+ if (page) {
+ /*
+ * Do only loose check w/o serialization.
+ * mem_cgroup_move_account() checks the page is valid or
+ * not under LRU exclusion.
+ */
+ if (page->mem_cgroup == mc.from) {
+ ret = MC_TARGET_PAGE;
+ if (target)
+ target->page = page;
+ }
+ if (!ret || !target)
+ put_page(page);
+ }
+ /* There is a swap entry and a page doesn't exist or isn't charged */
+ if (ent.val && !ret &&
+ mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) {
+ ret = MC_TARGET_SWAP;
+ if (target)
+ target->ent = ent;
+ }
+ return ret;
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+/*
+ * We don't consider swapping or file mapped pages because THP does not
+ * support them for now.
+ * Caller should make sure that pmd_trans_huge(pmd) is true.
+ */
+static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
+ unsigned long addr, pmd_t pmd, union mc_target *target)
+{
+ struct page *page = NULL;
+ enum mc_target_type ret = MC_TARGET_NONE;
+
+ page = pmd_page(pmd);
+ VM_BUG_ON_PAGE(!page || !PageHead(page), page);
+ if (!(mc.flags & MOVE_ANON))
+ return ret;
+ if (page->mem_cgroup == mc.from) {
+ ret = MC_TARGET_PAGE;
+ if (target) {
+ get_page(page);
+ target->page = page;
+ }
+ }
+ return ret;
+}
+#else
+static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
+ unsigned long addr, pmd_t pmd, union mc_target *target)
+{
+ return MC_TARGET_NONE;
+}
+#endif
+
+static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ struct vm_area_struct *vma = walk->vma;
+ pte_t *pte;
+ spinlock_t *ptl;
+
+ if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
+ if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE)
+ mc.precharge += HPAGE_PMD_NR;
+ spin_unlock(ptl);
+ return 0;
+ }
+
+ if (pmd_trans_unstable(pmd))
+ return 0;
+ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+ for (; addr != end; pte++, addr += PAGE_SIZE)
+ if (get_mctgt_type(vma, addr, *pte, NULL))
+ mc.precharge++; /* increment precharge temporarily */
+ pte_unmap_unlock(pte - 1, ptl);
+ cond_resched();
+
+ return 0;
+}
+
+static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
+{
+ unsigned long precharge;
+
+ struct mm_walk mem_cgroup_count_precharge_walk = {
+ .pmd_entry = mem_cgroup_count_precharge_pte_range,
+ .mm = mm,
+ };
+ down_read(&mm->mmap_sem);
+ walk_page_range(0, ~0UL, &mem_cgroup_count_precharge_walk);
+ up_read(&mm->mmap_sem);
+
+ precharge = mc.precharge;
+ mc.precharge = 0;
+
+ return precharge;
+}
+
+static int mem_cgroup_precharge_mc(struct mm_struct *mm)
+{
+ unsigned long precharge = mem_cgroup_count_precharge(mm);
+
+ VM_BUG_ON(mc.moving_task);
+ mc.moving_task = current;
+ return mem_cgroup_do_precharge(precharge);
+}
+
+/* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
+static void __mem_cgroup_clear_mc(void)
+{
+ struct mem_cgroup *from = mc.from;
+ struct mem_cgroup *to = mc.to;
+
+ /* we must uncharge all the leftover precharges from mc.to */
+ if (mc.precharge) {
+ cancel_charge(mc.to, mc.precharge);
+ mc.precharge = 0;
+ }
+ /*
+ * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
+ * we must uncharge here.
+ */
+ if (mc.moved_charge) {
+ cancel_charge(mc.from, mc.moved_charge);
+ mc.moved_charge = 0;
+ }
+ /* we must fixup refcnts and charges */
+ if (mc.moved_swap) {
+ /* uncharge swap account from the old cgroup */
+ if (!mem_cgroup_is_root(mc.from))
+ page_counter_uncharge(&mc.from->memsw, mc.moved_swap);
+
+ /*
+ * we charged both to->memory and to->memsw, so we
+ * should uncharge to->memory.
+ */
+ if (!mem_cgroup_is_root(mc.to))
+ page_counter_uncharge(&mc.to->memory, mc.moved_swap);
+
+ css_put_many(&mc.from->css, mc.moved_swap);
+
+ /* we've already done css_get(mc.to) */
+ mc.moved_swap = 0;
+ }
+ memcg_oom_recover(from);
+ memcg_oom_recover(to);
+ wake_up_all(&mc.waitq);
+}
+
+static void mem_cgroup_clear_mc(void)
+{
+ /*
+ * we must clear moving_task before waking up waiters at the end of
+ * task migration.
+ */
+ mc.moving_task = NULL;
+ __mem_cgroup_clear_mc();
+ spin_lock(&mc.lock);
+ mc.from = NULL;
+ mc.to = NULL;
+ spin_unlock(&mc.lock);
+}
+
+static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
+ struct cgroup_taskset *tset)
+{
+ struct task_struct *p = cgroup_taskset_first(tset);
+ int ret = 0;
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ unsigned long move_flags;
+
+ /*
+ * We are now commited to this value whatever it is. Changes in this
+ * tunable will only affect upcoming migrations, not the current one.
+ * So we need to save it, and keep it going.
+ */
+ move_flags = READ_ONCE(memcg->move_charge_at_immigrate);
+ if (move_flags) {
+ struct mm_struct *mm;
+ struct mem_cgroup *from = mem_cgroup_from_task(p);
+
+ VM_BUG_ON(from == memcg);
+
+ mm = get_task_mm(p);
+ if (!mm)
+ return 0;
+ /* We move charges only when we move a owner of the mm */
+ if (mm->owner == p) {
+ VM_BUG_ON(mc.from);
+ VM_BUG_ON(mc.to);
+ VM_BUG_ON(mc.precharge);
+ VM_BUG_ON(mc.moved_charge);
+ VM_BUG_ON(mc.moved_swap);
+
+ spin_lock(&mc.lock);
+ mc.from = from;
+ mc.to = memcg;
+ mc.flags = move_flags;
+ spin_unlock(&mc.lock);
+ /* We set mc.moving_task later */
+
+ ret = mem_cgroup_precharge_mc(mm);
+ if (ret)
+ mem_cgroup_clear_mc();
+ }
+ mmput(mm);
+ }
+ return ret;
+}
+
+static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css,
+ struct cgroup_taskset *tset)
+{
+ if (mc.to)
+ mem_cgroup_clear_mc();
+}
+
+static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ int ret = 0;
+ struct vm_area_struct *vma = walk->vma;
+ pte_t *pte;
+ spinlock_t *ptl;
+ enum mc_target_type target_type;
+ union mc_target target;
+ struct page *page;
+
+ /*
+ * We don't take compound_lock() here but no race with splitting thp
+ * happens because:
+ * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
+ * under splitting, which means there's no concurrent thp split,
+ * - if another thread runs into split_huge_page() just after we
+ * entered this if-block, the thread must wait for page table lock
+ * to be unlocked in __split_huge_page_splitting(), where the main
+ * part of thp split is not executed yet.
+ */
+ if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
+ if (mc.precharge < HPAGE_PMD_NR) {
+ spin_unlock(ptl);
+ return 0;
+ }
+ target_type = get_mctgt_type_thp(vma, addr, *pmd, &target);
+ if (target_type == MC_TARGET_PAGE) {
+ page = target.page;
+ if (!isolate_lru_page(page)) {
+ if (!mem_cgroup_move_account(page, HPAGE_PMD_NR,
+ mc.from, mc.to)) {
+ mc.precharge -= HPAGE_PMD_NR;
+ mc.moved_charge += HPAGE_PMD_NR;
+ }
+ putback_lru_page(page);
+ }
+ put_page(page);
+ }
+ spin_unlock(ptl);
+ return 0;
+ }
+
+ if (pmd_trans_unstable(pmd))
+ return 0;
+retry:
+ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+ for (; addr != end; addr += PAGE_SIZE) {
+ pte_t ptent = *(pte++);
+ swp_entry_t ent;
+
+ if (!mc.precharge)
+ break;
+
+ switch (get_mctgt_type(vma, addr, ptent, &target)) {
+ case MC_TARGET_PAGE:
+ page = target.page;
+ if (isolate_lru_page(page))
+ goto put;
+ if (!mem_cgroup_move_account(page, 1, mc.from, mc.to)) {
+ mc.precharge--;
+ /* we uncharge from mc.from later. */
+ mc.moved_charge++;
+ }
+ putback_lru_page(page);
+put: /* get_mctgt_type() gets the page */
+ put_page(page);
+ break;
+ case MC_TARGET_SWAP:
+ ent = target.ent;
+ if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) {
+ mc.precharge--;
+ /* we fixup refcnts and charges later. */
+ mc.moved_swap++;
+ }
+ break;
+ default:
+ break;
+ }
+ }
+ pte_unmap_unlock(pte - 1, ptl);
+ cond_resched();
+
+ if (addr != end) {
+ /*
+ * We have consumed all precharges we got in can_attach().
+ * We try charge one by one, but don't do any additional
+ * charges to mc.to if we have failed in charge once in attach()
+ * phase.
+ */
+ ret = mem_cgroup_do_precharge(1);
+ if (!ret)
+ goto retry;
+ }
+
+ return ret;
+}
+
+static void mem_cgroup_move_charge(struct mm_struct *mm)
+{
+ struct mm_walk mem_cgroup_move_charge_walk = {
+ .pmd_entry = mem_cgroup_move_charge_pte_range,
+ .mm = mm,
+ };
+
+ lru_add_drain_all();
+ /*
+ * Signal mem_cgroup_begin_page_stat() to take the memcg's
+ * move_lock while we're moving its pages to another memcg.
+ * Then wait for already started RCU-only updates to finish.
+ */
+ atomic_inc(&mc.from->moving_account);
+ synchronize_rcu();
+retry:
+ if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
+ /*
+ * Someone who are holding the mmap_sem might be waiting in
+ * waitq. So we cancel all extra charges, wake up all waiters,
+ * and retry. Because we cancel precharges, we might not be able
+ * to move enough charges, but moving charge is a best-effort
+ * feature anyway, so it wouldn't be a big problem.
+ */
+ __mem_cgroup_clear_mc();
+ cond_resched();
+ goto retry;
+ }
+ /*
+ * When we have consumed all precharges and failed in doing
+ * additional charge, the page walk just aborts.
+ */
+ walk_page_range(0, ~0UL, &mem_cgroup_move_charge_walk);
+ up_read(&mm->mmap_sem);
+ atomic_dec(&mc.from->moving_account);
+}
+
+static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
+ struct cgroup_taskset *tset)
+{
+ struct task_struct *p = cgroup_taskset_first(tset);
+ struct mm_struct *mm = get_task_mm(p);
+
+ if (mm) {
+ if (mc.to)
+ mem_cgroup_move_charge(mm);
+ mmput(mm);
+ }
+ if (mc.to)
+ mem_cgroup_clear_mc();
+}
+#else /* !CONFIG_MMU */
+static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
+ struct cgroup_taskset *tset)
+{
+ return 0;
+}
+static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css,
+ struct cgroup_taskset *tset)
+{
+}
+static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
+ struct cgroup_taskset *tset)
+{
+}
+#endif
+
+/*
+ * Cgroup retains root cgroups across [un]mount cycles making it necessary
+ * to verify whether we're attached to the default hierarchy on each mount
+ * attempt.
+ */
+static void mem_cgroup_bind(struct cgroup_subsys_state *root_css)
+{
+ /*
+ * use_hierarchy is forced on the default hierarchy. cgroup core
+ * guarantees that @root doesn't have any children, so turning it
+ * on for the root memcg is enough.
+ */
+ if (cgroup_on_dfl(root_css->cgroup))
+ root_mem_cgroup->use_hierarchy = true;
+ else
+ root_mem_cgroup->use_hierarchy = false;
+}
+
+static u64 memory_current_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ return mem_cgroup_usage(mem_cgroup_from_css(css), false);
+}
+
+static int memory_low_show(struct seq_file *m, void *v)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+ unsigned long low = READ_ONCE(memcg->low);
+
+ if (low == PAGE_COUNTER_MAX)
+ seq_puts(m, "max\n");
+ else
+ seq_printf(m, "%llu\n", (u64)low * PAGE_SIZE);
+
+ return 0;
+}
+
+static ssize_t memory_low_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
+ unsigned long low;
+ int err;
+
+ buf = strstrip(buf);
+ err = page_counter_memparse(buf, "max", &low);
+ if (err)
+ return err;
+
+ memcg->low = low;
+
+ return nbytes;
+}
+
+static int memory_high_show(struct seq_file *m, void *v)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+ unsigned long high = READ_ONCE(memcg->high);
+
+ if (high == PAGE_COUNTER_MAX)
+ seq_puts(m, "max\n");
+ else
+ seq_printf(m, "%llu\n", (u64)high * PAGE_SIZE);
+
+ return 0;
+}
+
+static ssize_t memory_high_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
+ unsigned long high;
+ int err;
+
+ buf = strstrip(buf);
+ err = page_counter_memparse(buf, "max", &high);
+ if (err)
+ return err;
+
+ memcg->high = high;
+
+ return nbytes;
+}
+
+static int memory_max_show(struct seq_file *m, void *v)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+ unsigned long max = READ_ONCE(memcg->memory.limit);
+
+ if (max == PAGE_COUNTER_MAX)
+ seq_puts(m, "max\n");
+ else
+ seq_printf(m, "%llu\n", (u64)max * PAGE_SIZE);
+
+ return 0;
+}
+
+static ssize_t memory_max_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
+ unsigned long max;
+ int err;
+
+ buf = strstrip(buf);
+ err = page_counter_memparse(buf, "max", &max);
+ if (err)
+ return err;
+
+ err = mem_cgroup_resize_limit(memcg, max);
+ if (err)
+ return err;
+
+ return nbytes;
+}
+
+static int memory_events_show(struct seq_file *m, void *v)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+
+ seq_printf(m, "low %lu\n", mem_cgroup_read_events(memcg, MEMCG_LOW));
+ seq_printf(m, "high %lu\n", mem_cgroup_read_events(memcg, MEMCG_HIGH));
+ seq_printf(m, "max %lu\n", mem_cgroup_read_events(memcg, MEMCG_MAX));
+ seq_printf(m, "oom %lu\n", mem_cgroup_read_events(memcg, MEMCG_OOM));
+
+ return 0;
+}
+
+static struct cftype memory_files[] = {
+ {
+ .name = "current",
+ .read_u64 = memory_current_read,
+ },
+ {
+ .name = "low",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = memory_low_show,
+ .write = memory_low_write,
+ },
+ {
+ .name = "high",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = memory_high_show,
+ .write = memory_high_write,
+ },
+ {
+ .name = "max",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = memory_max_show,
+ .write = memory_max_write,
+ },
+ {
+ .name = "events",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = memory_events_show,
+ },
+ { } /* terminate */
+};
+
+struct cgroup_subsys memory_cgrp_subsys = {
+ .css_alloc = mem_cgroup_css_alloc,
+ .css_online = mem_cgroup_css_online,
+ .css_offline = mem_cgroup_css_offline,
+ .css_free = mem_cgroup_css_free,
+ .css_reset = mem_cgroup_css_reset,
+ .can_attach = mem_cgroup_can_attach,
+ .cancel_attach = mem_cgroup_cancel_attach,
+ .attach = mem_cgroup_move_task,
+ .bind = mem_cgroup_bind,
+ .dfl_cftypes = memory_files,
+ .legacy_cftypes = mem_cgroup_legacy_files,
+ .early_init = 0,
+};
+
+/**
+ * mem_cgroup_events - count memory events against a cgroup
+ * @memcg: the memory cgroup
+ * @idx: the event index
+ * @nr: the number of events to account for
+ */
+void mem_cgroup_events(struct mem_cgroup *memcg,
+ enum mem_cgroup_events_index idx,
+ unsigned int nr)
+{
+ this_cpu_add(memcg->stat->events[idx], nr);
+}
+
+/**
+ * mem_cgroup_low - check if memory consumption is below the normal range
+ * @root: the highest ancestor to consider
+ * @memcg: the memory cgroup to check
+ *
+ * Returns %true if memory consumption of @memcg, and that of all
+ * configurable ancestors up to @root, is below the normal range.
+ */
+bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg)
+{
+ if (mem_cgroup_disabled())
+ return false;
+
+ /*
+ * The toplevel group doesn't have a configurable range, so
+ * it's never low when looked at directly, and it is not
+ * considered an ancestor when assessing the hierarchy.
+ */
+
+ if (memcg == root_mem_cgroup)
+ return false;
+
+ if (page_counter_read(&memcg->memory) >= memcg->low)
+ return false;
+
+ while (memcg != root) {
+ memcg = parent_mem_cgroup(memcg);
+
+ if (memcg == root_mem_cgroup)
+ break;
+
+ if (page_counter_read(&memcg->memory) >= memcg->low)
+ return false;
+ }
+ return true;
+}
+
+/**
+ * mem_cgroup_try_charge - try charging a page
+ * @page: page to charge
+ * @mm: mm context of the victim
+ * @gfp_mask: reclaim mode
+ * @memcgp: charged memcg return
+ *
+ * Try to charge @page to the memcg that @mm belongs to, reclaiming
+ * pages according to @gfp_mask if necessary.
+ *
+ * Returns 0 on success, with *@memcgp pointing to the charged memcg.
+ * Otherwise, an error code is returned.
+ *
+ * After page->mapping has been set up, the caller must finalize the
+ * charge with mem_cgroup_commit_charge(). Or abort the transaction
+ * with mem_cgroup_cancel_charge() in case page instantiation fails.
+ */
+int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
+ gfp_t gfp_mask, struct mem_cgroup **memcgp)
+{
+ struct mem_cgroup *memcg = NULL;
+ unsigned int nr_pages = 1;
+ int ret = 0;
+
+ if (mem_cgroup_disabled())
+ goto out;
+
+ if (PageSwapCache(page)) {
+ /*
+ * Every swap fault against a single page tries to charge the
+ * page, bail as early as possible. shmem_unuse() encounters
+ * already charged pages, too. The USED bit is protected by
+ * the page lock, which serializes swap cache removal, which
+ * in turn serializes uncharging.
+ */
+ if (page->mem_cgroup)
+ goto out;
+ }
+
+ if (PageTransHuge(page)) {
+ nr_pages <<= compound_order(page);
+ VM_BUG_ON_PAGE(!PageTransHuge(page), page);
+ }
+
+ if (do_swap_account && PageSwapCache(page))
+ memcg = try_get_mem_cgroup_from_page(page);
+ if (!memcg)
+ memcg = get_mem_cgroup_from_mm(mm);
+
+ ret = try_charge(memcg, gfp_mask, nr_pages);
+
+ css_put(&memcg->css);
+
+ if (ret == -EINTR) {
+ memcg = root_mem_cgroup;
+ ret = 0;
+ }
+out:
+ *memcgp = memcg;
+ return ret;
+}
+
+/**
+ * mem_cgroup_commit_charge - commit a page charge
+ * @page: page to charge
+ * @memcg: memcg to charge the page to
+ * @lrucare: page might be on LRU already
+ *
+ * Finalize a charge transaction started by mem_cgroup_try_charge(),
+ * after page->mapping has been set up. This must happen atomically
+ * as part of the page instantiation, i.e. under the page table lock
+ * for anonymous pages, under the page lock for page and swap cache.
+ *
+ * In addition, the page must not be on the LRU during the commit, to
+ * prevent racing with task migration. If it might be, use @lrucare.
+ *
+ * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
+ */
+void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,
+ bool lrucare)
+{
+ unsigned int nr_pages = 1;
+
+ VM_BUG_ON_PAGE(!page->mapping, page);
+ VM_BUG_ON_PAGE(PageLRU(page) && !lrucare, page);
+
+ if (mem_cgroup_disabled())
+ return;
+ /*
+ * Swap faults will attempt to charge the same page multiple
+ * times. But reuse_swap_page() might have removed the page
+ * from swapcache already, so we can't check PageSwapCache().
+ */
+ if (!memcg)
+ return;
+
+ commit_charge(page, memcg, lrucare);
+
+ if (PageTransHuge(page)) {
+ nr_pages <<= compound_order(page);
+ VM_BUG_ON_PAGE(!PageTransHuge(page), page);
+ }
+
+ local_lock_irq(event_lock);
+ mem_cgroup_charge_statistics(memcg, page, nr_pages);
+ memcg_check_events(memcg, page);
+ local_unlock_irq(event_lock);
+
+ if (do_swap_account && PageSwapCache(page)) {
+ swp_entry_t entry = { .val = page_private(page) };
+ /*
+ * The swap entry might not get freed for a long time,
+ * let's not wait for it. The page already received a
+ * memory+swap charge, drop the swap entry duplicate.
+ */
+ mem_cgroup_uncharge_swap(entry);
+ }
+}
+
+/**
+ * mem_cgroup_cancel_charge - cancel a page charge
+ * @page: page to charge
+ * @memcg: memcg to charge the page to
+ *
+ * Cancel a charge transaction started by mem_cgroup_try_charge().
+ */
+void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg)
+{
+ unsigned int nr_pages = 1;
+
+ if (mem_cgroup_disabled())
+ return;
+ /*
+ * Swap faults will attempt to charge the same page multiple
+ * times. But reuse_swap_page() might have removed the page
+ * from swapcache already, so we can't check PageSwapCache().
+ */
+ if (!memcg)
+ return;
+
+ if (PageTransHuge(page)) {
+ nr_pages <<= compound_order(page);
+ VM_BUG_ON_PAGE(!PageTransHuge(page), page);
+ }
+
+ cancel_charge(memcg, nr_pages);
+}
+
+static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout,
+ unsigned long nr_anon, unsigned long nr_file,
+ unsigned long nr_huge, struct page *dummy_page)
+{
+ unsigned long nr_pages = nr_anon + nr_file;
+ unsigned long flags;
+
+ if (!mem_cgroup_is_root(memcg)) {
+ page_counter_uncharge(&memcg->memory, nr_pages);
+ if (do_swap_account)
+ page_counter_uncharge(&memcg->memsw, nr_pages);
+ memcg_oom_recover(memcg);
+ }
+
+ local_lock_irqsave(event_lock, flags);
+ __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS], nr_anon);
+ __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_CACHE], nr_file);
+ __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], nr_huge);
+ __this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT], pgpgout);
+ __this_cpu_add(memcg->stat->nr_page_events, nr_pages);
+ memcg_check_events(memcg, dummy_page);
+ local_unlock_irqrestore(event_lock, flags);
+
+ if (!mem_cgroup_is_root(memcg))
+ css_put_many(&memcg->css, nr_pages);
+}
+
+static void uncharge_list(struct list_head *page_list)
+{
+ struct mem_cgroup *memcg = NULL;
+ unsigned long nr_anon = 0;
+ unsigned long nr_file = 0;
+ unsigned long nr_huge = 0;
+ unsigned long pgpgout = 0;
+ struct list_head *next;
+ struct page *page;
+
+ next = page_list->next;
+ do {
+ unsigned int nr_pages = 1;
+
+ page = list_entry(next, struct page, lru);
+ next = page->lru.next;
+
+ VM_BUG_ON_PAGE(PageLRU(page), page);
+ VM_BUG_ON_PAGE(page_count(page), page);
+
+ if (!page->mem_cgroup)
+ continue;
+
+ /*
+ * Nobody should be changing or seriously looking at
+ * page->mem_cgroup at this point, we have fully
+ * exclusive access to the page.
+ */
+
+ if (memcg != page->mem_cgroup) {
+ if (memcg) {
+ uncharge_batch(memcg, pgpgout, nr_anon, nr_file,
+ nr_huge, page);
+ pgpgout = nr_anon = nr_file = nr_huge = 0;
+ }
+ memcg = page->mem_cgroup;
+ }
+
+ if (PageTransHuge(page)) {
+ nr_pages <<= compound_order(page);
+ VM_BUG_ON_PAGE(!PageTransHuge(page), page);
+ nr_huge += nr_pages;
+ }
+
+ if (PageAnon(page))
+ nr_anon += nr_pages;
+ else
+ nr_file += nr_pages;
+
+ page->mem_cgroup = NULL;
+
+ pgpgout++;
+ } while (next != page_list);
+
+ if (memcg)
+ uncharge_batch(memcg, pgpgout, nr_anon, nr_file,
+ nr_huge, page);
+}
+
+/**
+ * mem_cgroup_uncharge - uncharge a page
+ * @page: page to uncharge
+ *
+ * Uncharge a page previously charged with mem_cgroup_try_charge() and
+ * mem_cgroup_commit_charge().
+ */
+void mem_cgroup_uncharge(struct page *page)
+{
+ if (mem_cgroup_disabled())
+ return;
+
+ /* Don't touch page->lru of any random page, pre-check: */
+ if (!page->mem_cgroup)
+ return;
+
+ INIT_LIST_HEAD(&page->lru);
+ uncharge_list(&page->lru);
+}
+
+/**
+ * mem_cgroup_uncharge_list - uncharge a list of page
+ * @page_list: list of pages to uncharge
+ *
+ * Uncharge a list of pages previously charged with
+ * mem_cgroup_try_charge() and mem_cgroup_commit_charge().
+ */
+void mem_cgroup_uncharge_list(struct list_head *page_list)
+{
+ if (mem_cgroup_disabled())
+ return;
+
+ if (!list_empty(page_list))
+ uncharge_list(page_list);
+}
+
+/**
+ * mem_cgroup_migrate - migrate a charge to another page
+ * @oldpage: currently charged page
+ * @newpage: page to transfer the charge to
+ * @lrucare: either or both pages might be on the LRU already
+ *
+ * Migrate the charge from @oldpage to @newpage.
+ *
+ * Both pages must be locked, @newpage->mapping must be set up.
+ */
+void mem_cgroup_migrate(struct page *oldpage, struct page *newpage,
+ bool lrucare)
+{
+ struct mem_cgroup *memcg;
+ int isolated;
+
+ VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage);
+ VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
+ VM_BUG_ON_PAGE(!lrucare && PageLRU(oldpage), oldpage);
+ VM_BUG_ON_PAGE(!lrucare && PageLRU(newpage), newpage);
+ VM_BUG_ON_PAGE(PageAnon(oldpage) != PageAnon(newpage), newpage);
+ VM_BUG_ON_PAGE(PageTransHuge(oldpage) != PageTransHuge(newpage),
+ newpage);
+
+ if (mem_cgroup_disabled())
+ return;
+
+ /* Page cache replacement: new page already charged? */
+ if (newpage->mem_cgroup)
+ return;
+
+ /*
+ * Swapcache readahead pages can get migrated before being
+ * charged, and migration from compaction can happen to an
+ * uncharged page when the PFN walker finds a page that
+ * reclaim just put back on the LRU but has not released yet.
+ */
+ memcg = oldpage->mem_cgroup;
+ if (!memcg)
+ return;
+
+ if (lrucare)
+ lock_page_lru(oldpage, &isolated);
+
+ oldpage->mem_cgroup = NULL;
+
+ if (lrucare)
+ unlock_page_lru(oldpage, isolated);
+
+ commit_charge(newpage, memcg, lrucare);
+}
+
+/*
+ * subsys_initcall() for memory controller.
+ *
+ * Some parts like hotcpu_notifier() have to be initialized from this context
+ * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
+ * everything that doesn't depend on a specific mem_cgroup structure should
+ * be initialized from here.
+ */
+static int __init mem_cgroup_init(void)
+{
+ int cpu, node;
+
+ hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
+
+ for_each_possible_cpu(cpu)
+ INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work,
+ drain_local_stock);
+
+ for_each_node(node) {
+ struct mem_cgroup_tree_per_node *rtpn;
+ int zone;
+
+ rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL,
+ node_online(node) ? node : NUMA_NO_NODE);
+
+ for (zone = 0; zone < MAX_NR_ZONES; zone++) {
+ struct mem_cgroup_tree_per_zone *rtpz;
+
+ rtpz = &rtpn->rb_tree_per_zone[zone];
+ rtpz->rb_root = RB_ROOT;
+ spin_lock_init(&rtpz->lock);
+ }
+ soft_limit_tree.rb_tree_per_node[node] = rtpn;
+ }
+
+ return 0;
+}
+subsys_initcall(mem_cgroup_init);
+
+#ifdef CONFIG_MEMCG_SWAP
+/**
+ * mem_cgroup_swapout - transfer a memsw charge to swap
+ * @page: page whose memsw charge to transfer
+ * @entry: swap entry to move the charge to
+ *
+ * Transfer the memsw charge of @page to @entry.
+ */
+void mem_cgroup_swapout(struct page *page, swp_entry_t entry)
+{
+ struct mem_cgroup *memcg;
+ unsigned short oldid;
+ unsigned long flags;
+
+ VM_BUG_ON_PAGE(PageLRU(page), page);
+ VM_BUG_ON_PAGE(page_count(page), page);
+
+ if (!do_swap_account)
+ return;
+
+ memcg = page->mem_cgroup;
+
+ /* Readahead page, never charged */
+ if (!memcg)
+ return;
+
+ oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg));
+ VM_BUG_ON_PAGE(oldid, page);
+ mem_cgroup_swap_statistics(memcg, true);
+
+ page->mem_cgroup = NULL;
+
+ if (!mem_cgroup_is_root(memcg))
+ page_counter_uncharge(&memcg->memory, 1);
+
+ local_lock_irqsave(event_lock, flags);
+ /* Caller disabled preemption with mapping->tree_lock */
+ mem_cgroup_charge_statistics(memcg, page, -1);
+ memcg_check_events(memcg, page);
+ local_unlock_irqrestore(event_lock, flags);
+}
+
+/**
+ * mem_cgroup_uncharge_swap - uncharge a swap entry
+ * @entry: swap entry to uncharge
+ *
+ * Drop the memsw charge associated with @entry.
+ */
+void mem_cgroup_uncharge_swap(swp_entry_t entry)
+{
+ struct mem_cgroup *memcg;
+ unsigned short id;
+
+ if (!do_swap_account)
+ return;
+
+ id = swap_cgroup_record(entry, 0);
+ rcu_read_lock();
+ memcg = mem_cgroup_from_id(id);
+ if (memcg) {
+ if (!mem_cgroup_is_root(memcg))
+ page_counter_uncharge(&memcg->memsw, 1);
+ mem_cgroup_swap_statistics(memcg, false);
+ css_put(&memcg->css);
+ }
+ rcu_read_unlock();
+}
+
+/* for remember boot option*/
+#ifdef CONFIG_MEMCG_SWAP_ENABLED
+static int really_do_swap_account __initdata = 1;
+#else
+static int really_do_swap_account __initdata;
+#endif
+
+static int __init enable_swap_account(char *s)
+{
+ if (!strcmp(s, "1"))
+ really_do_swap_account = 1;
+ else if (!strcmp(s, "0"))
+ really_do_swap_account = 0;
+ return 1;
+}
+__setup("swapaccount=", enable_swap_account);
+
+static struct cftype memsw_cgroup_files[] = {
+ {
+ .name = "memsw.usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "memsw.max_usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
+ .write = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "memsw.limit_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
+ .write = mem_cgroup_write,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "memsw.failcnt",
+ .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
+ .write = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ { }, /* terminate */
+};
+
+static int __init mem_cgroup_swap_init(void)
+{
+ if (!mem_cgroup_disabled() && really_do_swap_account) {
+ do_swap_account = 1;
+ WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys,
+ memsw_cgroup_files));
+ }
+ return 0;
+}
+subsys_initcall(mem_cgroup_swap_init);
+
+#endif /* CONFIG_MEMCG_SWAP */
Code Review / kvmfornfv.git / blobdiff