| /* 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 |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| |
| #include <linux/res_counter.h> |
| #include <linux/memcontrol.h> |
| #include <linux/cgroup.h> |
| #include <linux/mm.h> |
| #include <linux/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/sort.h> |
| #include <linux/fs.h> |
| #include <linux/seq_file.h> |
| #include <linux/vmalloc.h> |
| #include <linux/vmpressure.h> |
| #include <linux/mm_inline.h> |
| #include <linux/page_cgroup.h> |
| #include <linux/cpu.h> |
| #include <linux/oom.h> |
| #include "internal.h" |
| #include <net/sock.h> |
| #include <net/ip.h> |
| #include <net/tcp_memcontrol.h> |
| |
| #include <asm/uaccess.h> |
| |
| #include <trace/events/vmscan.h> |
| |
| struct cgroup_subsys mem_cgroup_subsys __read_mostly; |
| EXPORT_SYMBOL(mem_cgroup_subsys); |
| |
| #define MEM_CGROUP_RECLAIM_RETRIES 5 |
| static struct mem_cgroup *root_mem_cgroup __read_mostly; |
| |
| #ifdef CONFIG_MEMCG_SWAP |
| /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */ |
| int do_swap_account __read_mostly; |
| |
| /* 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 = 0; |
| #endif |
| |
| #else |
| #define do_swap_account 0 |
| #endif |
| |
| |
| static const char * const mem_cgroup_stat_names[] = { |
| "cache", |
| "rss", |
| "rss_huge", |
| "mapped_file", |
| "writeback", |
| "swap", |
| }; |
| |
| enum mem_cgroup_events_index { |
| MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */ |
| MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */ |
| MEM_CGROUP_EVENTS_PGFAULT, /* # of page-faults */ |
| MEM_CGROUP_EVENTS_PGMAJFAULT, /* # of major page-faults */ |
| MEM_CGROUP_EVENTS_NSTATS, |
| }; |
| |
| 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[MEM_CGROUP_EVENTS_NSTATS]; |
| unsigned long nr_page_events; |
| unsigned long targets[MEM_CGROUP_NTARGETS]; |
| }; |
| |
| struct mem_cgroup_reclaim_iter { |
| /* |
| * last scanned hierarchy member. Valid only if last_dead_count |
| * matches memcg->dead_count of the hierarchy root group. |
| */ |
| struct mem_cgroup *last_visited; |
| unsigned long last_dead_count; |
| |
| /* 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 mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1]; |
| |
| struct rb_node tree_node; /* RB tree node */ |
| unsigned long 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; |
| u64 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; |
| }; |
| |
| 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. |
| * |
| * TODO: Add a water mark for the memory controller. Reclaim will begin when |
| * we hit the water mark. May be even add a low water mark, such that |
| * no reclaim occurs from a cgroup at it's low water mark, this is |
| * a feature that will be implemented much later in the future. |
| */ |
| struct mem_cgroup { |
| struct cgroup_subsys_state css; |
| /* |
| * the counter to account for memory usage |
| */ |
| struct res_counter res; |
| |
| /* vmpressure notifications */ |
| struct vmpressure vmpressure; |
| |
| /* |
| * the counter to account for mem+swap usage. |
| */ |
| struct res_counter memsw; |
| |
| /* |
| * the counter to account for kernel memory usage. |
| */ |
| struct res_counter kmem; |
| /* |
| * Should the accounting and control be hierarchical, per subtree? |
| */ |
| bool use_hierarchy; |
| unsigned long kmem_account_flags; /* See KMEM_ACCOUNTED_*, below */ |
| |
| bool oom_lock; |
| atomic_t under_oom; |
| atomic_t oom_wakeups; |
| |
| int swappiness; |
| /* OOM-Killer disable */ |
| int oom_kill_disable; |
| |
| /* set when res.limit == memsw.limit */ |
| bool memsw_is_minimum; |
| |
| /* 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; |
| /* |
| * 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; |
| |
| atomic_t dead_count; |
| #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET) |
| struct cg_proto tcp_mem; |
| #endif |
| #if defined(CONFIG_MEMCG_KMEM) |
| /* analogous to slab_common's slab_caches list. per-memcg */ |
| struct list_head memcg_slab_caches; |
| /* Not a spinlock, we can take a lot of time walking the list */ |
| struct mutex slab_caches_mutex; |
| /* Index in the kmem_cache->memcg_params->memcg_caches array */ |
| int kmemcg_id; |
| #endif |
| |
| int last_scanned_node; |
| #if MAX_NUMNODES > 1 |
| nodemask_t scan_nodes; |
| atomic_t numainfo_events; |
| atomic_t numainfo_updating; |
| #endif |
| |
| struct mem_cgroup_per_node *nodeinfo[0]; |
| /* WARNING: nodeinfo must be the last member here */ |
| }; |
| |
| static size_t memcg_size(void) |
| { |
| return sizeof(struct mem_cgroup) + |
| nr_node_ids * sizeof(struct mem_cgroup_per_node); |
| } |
| |
| /* internal only representation about the status of kmem accounting. */ |
| enum { |
| KMEM_ACCOUNTED_ACTIVE = 0, /* accounted by this cgroup itself */ |
| KMEM_ACCOUNTED_ACTIVATED, /* static key enabled. */ |
| KMEM_ACCOUNTED_DEAD, /* dead memcg with pending kmem charges */ |
| }; |
| |
| /* We account when limit is on, but only after call sites are patched */ |
| #define KMEM_ACCOUNTED_MASK \ |
| ((1 << KMEM_ACCOUNTED_ACTIVE) | (1 << KMEM_ACCOUNTED_ACTIVATED)) |
| |
| #ifdef CONFIG_MEMCG_KMEM |
| static inline void memcg_kmem_set_active(struct mem_cgroup *memcg) |
| { |
| set_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags); |
| } |
| |
| static bool memcg_kmem_is_active(struct mem_cgroup *memcg) |
| { |
| return test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags); |
| } |
| |
| static void memcg_kmem_set_activated(struct mem_cgroup *memcg) |
| { |
| set_bit(KMEM_ACCOUNTED_ACTIVATED, &memcg->kmem_account_flags); |
| } |
| |
| static void memcg_kmem_clear_activated(struct mem_cgroup *memcg) |
| { |
| clear_bit(KMEM_ACCOUNTED_ACTIVATED, &memcg->kmem_account_flags); |
| } |
| |
| static void memcg_kmem_mark_dead(struct mem_cgroup *memcg) |
| { |
| /* |
| * Our caller must use css_get() first, because memcg_uncharge_kmem() |
| * will call css_put() if it sees the memcg is dead. |
| */ |
| smp_wmb(); |
| if (test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags)) |
| set_bit(KMEM_ACCOUNTED_DEAD, &memcg->kmem_account_flags); |
| } |
| |
| static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup *memcg) |
| { |
| return test_and_clear_bit(KMEM_ACCOUNTED_DEAD, |
| &memcg->kmem_account_flags); |
| } |
| #endif |
| |
| /* Stuffs for move charges at task migration. */ |
| /* |
| * Types of charges to be moved. "move_charge_at_immitgrate" and |
| * "immigrate_flags" are treated as a left-shifted bitmap of these types. |
| */ |
| enum move_type { |
| MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */ |
| MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */ |
| NR_MOVE_TYPE, |
| }; |
| |
| /* "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 immigrate_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), |
| }; |
| |
| static bool move_anon(void) |
| { |
| return test_bit(MOVE_CHARGE_TYPE_ANON, &mc.immigrate_flags); |
| } |
| |
| static bool move_file(void) |
| { |
| return test_bit(MOVE_CHARGE_TYPE_FILE, &mc.immigrate_flags); |
| } |
| |
| /* |
| * 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) |
| |
| /* |
| * Reclaim flags for mem_cgroup_hierarchical_reclaim |
| */ |
| #define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0 |
| #define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT) |
| #define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1 |
| #define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT) |
| |
| /* |
| * 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; |
| } |
| |
| struct vmpressure *css_to_vmpressure(struct cgroup_subsys_state *css) |
| { |
| return &mem_cgroup_from_css(css)->vmpressure; |
| } |
| |
| static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) |
| { |
| return (memcg == root_mem_cgroup); |
| } |
| |
| /* 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(&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); |
| |
| static void disarm_sock_keys(struct mem_cgroup *memcg) |
| { |
| if (!memcg_proto_activated(&memcg->tcp_mem)) |
| return; |
| static_key_slow_dec(&memcg_socket_limit_enabled); |
| } |
| #else |
| static void disarm_sock_keys(struct mem_cgroup *memcg) |
| { |
| } |
| #endif |
| |
| #ifdef CONFIG_MEMCG_KMEM |
| /* |
| * This will be the memcg's index in each cache's ->memcg_params->memcg_caches. |
| * There are two main reasons for not using the css_id for this: |
| * 1) 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. |
| * |
| * 2) In order not to violate the cgroup API, we would like to do all memory |
| * allocation in ->create(). At that point, we haven't yet allocated the |
| * css_id. Having a separate index prevents us from messing with the cgroup |
| * core for this |
| * |
| * The current size of the caches array is stored in |
| * memcg_limited_groups_array_size. It will double each time we have to |
| * increase it. |
| */ |
| static DEFINE_IDA(kmem_limited_groups); |
| int memcg_limited_groups_array_size; |
| |
| /* |
| * 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 css_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 |
| * css_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 65535 |
| |
| /* |
| * 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); |
| |
| static void disarm_kmem_keys(struct mem_cgroup *memcg) |
| { |
| if (memcg_kmem_is_active(memcg)) { |
| static_key_slow_dec(&memcg_kmem_enabled_key); |
| ida_simple_remove(&kmem_limited_groups, memcg->kmemcg_id); |
| } |
| /* |
| * This check can't live in kmem destruction function, |
| * since the charges will outlive the cgroup |
| */ |
| WARN_ON(res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0); |
| } |
| #else |
| static void disarm_kmem_keys(struct mem_cgroup *memcg) |
| { |
| } |
| #endif /* CONFIG_MEMCG_KMEM */ |
| |
| static void disarm_static_keys(struct mem_cgroup *memcg) |
| { |
| disarm_sock_keys(memcg); |
| disarm_kmem_keys(memcg); |
| } |
| |
| static void drain_all_stock_async(struct mem_cgroup *memcg); |
| |
| static struct mem_cgroup_per_zone * |
| mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid) |
| { |
| VM_BUG_ON((unsigned)nid >= nr_node_ids); |
| 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 * |
| page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page) |
| { |
| int nid = page_to_nid(page); |
| int zid = page_zonenum(page); |
| |
| return mem_cgroup_zoneinfo(memcg, nid, 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 *memcg, |
| struct mem_cgroup_per_zone *mz, |
| struct mem_cgroup_tree_per_zone *mctz, |
| unsigned long 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 *memcg, |
| struct mem_cgroup_per_zone *mz, |
| struct mem_cgroup_tree_per_zone *mctz) |
| { |
| if (!mz->on_tree) |
| return; |
| rb_erase(&mz->tree_node, &mctz->rb_root); |
| mz->on_tree = false; |
| } |
| |
| static void |
| mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, |
| struct mem_cgroup_per_zone *mz, |
| struct mem_cgroup_tree_per_zone *mctz) |
| { |
| spin_lock(&mctz->lock); |
| __mem_cgroup_remove_exceeded(memcg, mz, mctz); |
| spin_unlock(&mctz->lock); |
| } |
| |
| |
| static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) |
| { |
| unsigned long long excess; |
| struct mem_cgroup_per_zone *mz; |
| struct mem_cgroup_tree_per_zone *mctz; |
| int nid = page_to_nid(page); |
| int zid = page_zonenum(page); |
| mctz = soft_limit_tree_from_page(page); |
| |
| /* |
| * Necessary to update all ancestors when hierarchy is used. |
| * because their event counter is not touched. |
| */ |
| for (; memcg; memcg = parent_mem_cgroup(memcg)) { |
| mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
| excess = res_counter_soft_limit_excess(&memcg->res); |
| /* |
| * We have to update the tree if mz is on RB-tree or |
| * mem is over its softlimit. |
| */ |
| if (excess || mz->on_tree) { |
| spin_lock(&mctz->lock); |
| /* if on-tree, remove it */ |
| if (mz->on_tree) |
| __mem_cgroup_remove_exceeded(memcg, mz, mctz); |
| /* |
| * Insert again. mz->usage_in_excess will be updated. |
| * If excess is 0, no tree ops. |
| */ |
| __mem_cgroup_insert_exceeded(memcg, mz, mctz, excess); |
| spin_unlock(&mctz->lock); |
| } |
| } |
| } |
| |
| static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) |
| { |
| int node, zone; |
| struct mem_cgroup_per_zone *mz; |
| struct mem_cgroup_tree_per_zone *mctz; |
| |
| for_each_node(node) { |
| for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
| mz = mem_cgroup_zoneinfo(memcg, node, zone); |
| mctz = soft_limit_tree_node_zone(node, zone); |
| mem_cgroup_remove_exceeded(memcg, mz, mctz); |
| } |
| } |
| } |
| |
| static struct mem_cgroup_per_zone * |
| __mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) |
| { |
| struct rb_node *rightmost = NULL; |
| struct mem_cgroup_per_zone *mz; |
| |
| retry: |
| mz = NULL; |
| rightmost = rb_last(&mctz->rb_root); |
| if (!rightmost) |
| goto done; /* Nothing to reclaim from */ |
| |
| mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); |
| /* |
| * Remove the node now but someone else can add it back, |
| * we will to add it back at the end of reclaim to its correct |
| * position in the tree. |
| */ |
| __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); |
| if (!res_counter_soft_limit_excess(&mz->memcg->res) || |
| !css_tryget(&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(&mctz->lock); |
| mz = __mem_cgroup_largest_soft_limit_node(mctz); |
| spin_unlock(&mctz->lock); |
| return mz; |
| } |
| |
| /* |
| * Implementation Note: reading percpu statistics for memcg. |
| * |
| * Both of vmstat[] and percpu_counter has threshold and do periodic |
| * synchronization to implement "quick" read. There are trade-off between |
| * reading cost and precision of value. Then, we may have a chance to implement |
| * a periodic synchronizion of counter in memcg's counter. |
| * |
| * But this _read() function is used for user interface now. The user accounts |
| * memory usage by memory cgroup and he _always_ requires exact value because |
| * he accounts memory. Even if we provide quick-and-fuzzy read, we always |
| * have to visit all online cpus and make sum. So, for now, unnecessary |
| * synchronization is not implemented. (just implemented for cpu hotplug) |
| * |
| * If there are kernel internal actions which can make use of some not-exact |
| * value, and reading all cpu value can be performance bottleneck in some |
| * common workload, threashold and synchonization as vmstat[] should be |
| * implemented. |
| */ |
| static long mem_cgroup_read_stat(struct mem_cgroup *memcg, |
| enum mem_cgroup_stat_index idx) |
| { |
| long val = 0; |
| int cpu; |
| |
| get_online_cpus(); |
| for_each_online_cpu(cpu) |
| val += per_cpu(memcg->stat->count[idx], cpu); |
| #ifdef CONFIG_HOTPLUG_CPU |
| spin_lock(&memcg->pcp_counter_lock); |
| val += memcg->nocpu_base.count[idx]; |
| spin_unlock(&memcg->pcp_counter_lock); |
| #endif |
| put_online_cpus(); |
| return val; |
| } |
| |
| static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg, |
| bool charge) |
| { |
| int val = (charge) ? 1 : -1; |
| this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], 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, |
| bool anon, int nr_pages) |
| { |
| preempt_disable(); |
| |
| /* |
| * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is |
| * counted as CACHE even if it's on ANON LRU. |
| */ |
| if (anon) |
| __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); |
| |
| preempt_enable(); |
| } |
| |
| 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_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid, |
| unsigned int lru_mask) |
| { |
| struct mem_cgroup_per_zone *mz; |
| enum lru_list lru; |
| unsigned long ret = 0; |
| |
| mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
| |
| for_each_lru(lru) { |
| if (BIT(lru) & lru_mask) |
| ret += mz->lru_size[lru]; |
| } |
| return ret; |
| } |
| |
| static unsigned long |
| mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, |
| int nid, unsigned int lru_mask) |
| { |
| u64 total = 0; |
| int zid; |
| |
| for (zid = 0; zid < MAX_NR_ZONES; zid++) |
| total += mem_cgroup_zone_nr_lru_pages(memcg, |
| nid, zid, lru_mask); |
| |
| return total; |
| } |
| |
| static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, |
| unsigned int lru_mask) |
| { |
| int nid; |
| u64 total = 0; |
| |
| for_each_node_state(nid, N_MEMORY) |
| total += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask); |
| return total; |
| } |
| |
| static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, |
| enum mem_cgroup_events_target target) |
| { |
| unsigned long val, next; |
| |
| val = __this_cpu_read(memcg->stat->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) |
| { |
| preempt_disable(); |
| /* threshold event is triggered in finer grain than soft limit */ |
| if (unlikely(mem_cgroup_event_ratelimit(memcg, |
| MEM_CGROUP_TARGET_THRESH))) { |
| bool do_softlimit; |
| 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 |
| preempt_enable(); |
| |
| mem_cgroup_threshold(memcg); |
| if (unlikely(do_softlimit)) |
| mem_cgroup_update_tree(memcg, page); |
| #if MAX_NUMNODES > 1 |
| if (unlikely(do_numainfo)) |
| atomic_inc(&memcg->numainfo_events); |
| #endif |
| } else |
| preempt_enable(); |
| } |
| |
| struct mem_cgroup *mem_cgroup_from_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, mem_cgroup_subsys_id)); |
| } |
| |
| struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) |
| { |
| struct mem_cgroup *memcg = NULL; |
| |
| if (!mm) |
| return NULL; |
| /* |
| * Because we have no locks, mm->owner's may be being moved to other |
| * cgroup. We use css_tryget() here even if this looks |
| * pessimistic (rather than adding locks here). |
| */ |
| rcu_read_lock(); |
| do { |
| memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
| if (unlikely(!memcg)) |
| break; |
| } while (!css_tryget(&memcg->css)); |
| rcu_read_unlock(); |
| return memcg; |
| } |
| |
| /* |
| * Returns a next (in a pre-order walk) alive memcg (with elevated css |
| * ref. count) or NULL if the whole root's subtree has been visited. |
| * |
| * helper function to be used by mem_cgroup_iter |
| */ |
| static struct mem_cgroup *__mem_cgroup_iter_next(struct mem_cgroup *root, |
| struct mem_cgroup *last_visited) |
| { |
| struct cgroup_subsys_state *prev_css, *next_css; |
| |
| prev_css = last_visited ? &last_visited->css : NULL; |
| skip_node: |
| next_css = css_next_descendant_pre(prev_css, &root->css); |
| |
| /* |
| * Even if we found a group we have to make sure it is |
| * alive. css && !memcg means that the groups should be |
| * skipped and we should continue the tree walk. |
| * last_visited css is safe to use because it is |
| * protected by css_get and the tree walk is rcu safe. |
| */ |
| if (next_css) { |
| struct mem_cgroup *mem = mem_cgroup_from_css(next_css); |
| |
| if (css_tryget(&mem->css)) |
| return mem; |
| else { |
| prev_css = next_css; |
| goto skip_node; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| static void mem_cgroup_iter_invalidate(struct mem_cgroup *root) |
| { |
| /* |
| * When a group in the hierarchy below root is destroyed, the |
| * hierarchy iterator can no longer be trusted since it might |
| * have pointed to the destroyed group. Invalidate it. |
| */ |
| atomic_inc(&root->dead_count); |
| } |
| |
| static struct mem_cgroup * |
| mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter *iter, |
| struct mem_cgroup *root, |
| int *sequence) |
| { |
| struct mem_cgroup *position = NULL; |
| /* |
| * A cgroup destruction happens in two stages: offlining and |
| * release. They are separated by a RCU grace period. |
| * |
| * If the iterator is valid, we may still race with an |
| * offlining. The RCU lock ensures the object won't be |
| * released, tryget will fail if we lost the race. |
| */ |
| *sequence = atomic_read(&root->dead_count); |
| if (iter->last_dead_count == *sequence) { |
| smp_rmb(); |
| position = iter->last_visited; |
| if (position && !css_tryget(&position->css)) |
| position = NULL; |
| } |
| return position; |
| } |
| |
| static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter *iter, |
| struct mem_cgroup *last_visited, |
| struct mem_cgroup *new_position, |
| int sequence) |
| { |
| if (last_visited) |
| css_put(&last_visited->css); |
| /* |
| * We store the sequence count from the time @last_visited was |
| * loaded successfully instead of rereading it here so that we |
| * don't lose destruction events in between. We could have |
| * raced with the destruction of @new_position after all. |
| */ |
| iter->last_visited = new_position; |
| smp_wmb(); |
| iter->last_dead_count = sequence; |
| } |
| |
| /** |
| * mem_cgroup_iter - iterate over memory cgroup hierarchy |
| * @root: hierarchy root |
| * @prev: previously returned memcg, NULL on first invocation |
| * @reclaim: cookie for shared reclaim walks, NULL for full walks |
| * |
| * Returns references to children of the hierarchy below @root, or |
| * @root itself, or %NULL after a full round-trip. |
| * |
| * Caller must pass the return value in @prev on subsequent |
| * invocations for reference counting, or use mem_cgroup_iter_break() |
| * to cancel a hierarchy walk before the round-trip is complete. |
| * |
| * Reclaimers can specify a zone and a priority level in @reclaim to |
| * divide up the memcgs in the hierarchy among all concurrent |
| * reclaimers operating on the same zone and priority. |
| */ |
| struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, |
| struct mem_cgroup *prev, |
| struct mem_cgroup_reclaim_cookie *reclaim) |
| { |
| struct mem_cgroup *memcg = NULL; |
| struct mem_cgroup *last_visited = NULL; |
| |
| if (mem_cgroup_disabled()) |
| return NULL; |
| |
| if (!root) |
| root = root_mem_cgroup; |
| |
| if (prev && !reclaim) |
| last_visited = prev; |
| |
| if (!root->use_hierarchy && root != root_mem_cgroup) { |
| if (prev) |
| goto out_css_put; |
| return root; |
| } |
| |
| rcu_read_lock(); |
| while (!memcg) { |
| struct mem_cgroup_reclaim_iter *uninitialized_var(iter); |
| int uninitialized_var(seq); |
| |
| if (reclaim) { |
| int nid = zone_to_nid(reclaim->zone); |
| int zid = zone_idx(reclaim->zone); |
| struct mem_cgroup_per_zone *mz; |
| |
| mz = mem_cgroup_zoneinfo(root, nid, zid); |
| iter = &mz->reclaim_iter[reclaim->priority]; |
| if (prev && reclaim->generation != iter->generation) { |
| iter->last_visited = NULL; |
| goto out_unlock; |
| } |
| |
| last_visited = mem_cgroup_iter_load(iter, root, &seq); |
| } |
| |
| memcg = __mem_cgroup_iter_next(root, last_visited); |
| |
| if (reclaim) { |
| mem_cgroup_iter_update(iter, last_visited, memcg, seq); |
| |
| if (!memcg) |
| iter->generation++; |
| else if (!prev && memcg) |
| reclaim->generation = iter->generation; |
| } |
| |
| if (prev && !memcg) |
| goto out_unlock; |
| } |
| out_unlock: |
| rcu_read_unlock(); |
| out_css_put: |
| 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_zoneinfo(memcg, zone_to_nid(zone), zone_idx(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; |
| } |
| |
| /* |
| * Following LRU functions are allowed to be used without PCG_LOCK. |
| * Operations are called by routine of global LRU independently from memcg. |
| * What we have to take care of here is validness of pc->mem_cgroup. |
| * |
| * Changes to pc->mem_cgroup happens when |
| * 1. charge |
| * 2. moving account |
| * In typical case, "charge" is done before add-to-lru. Exception is SwapCache. |
| * It is added to LRU before charge. |
| * If PCG_USED bit is not set, page_cgroup is not added to this private LRU. |
| * When moving account, the page is not on LRU. It's isolated. |
| */ |
| |
| /** |
| * mem_cgroup_page_lruvec - return lruvec for adding an lru page |
| * @page: the page |
| * @zone: zone of the page |
| */ |
| struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone) |
| { |
| struct mem_cgroup_per_zone *mz; |
| struct mem_cgroup *memcg; |
| struct page_cgroup *pc; |
| struct lruvec *lruvec; |
| |
| if (mem_cgroup_disabled()) { |
| lruvec = &zone->lruvec; |
| goto out; |
| } |
| |
| pc = lookup_page_cgroup(page); |
| memcg = pc->mem_cgroup; |
| |
| /* |
| * Surreptitiously switch any uncharged offlist page to root: |
| * an uncharged page off lru does nothing to secure |
| * its former mem_cgroup from sudden removal. |
| * |
| * Our caller holds lru_lock, and PageCgroupUsed is updated |
| * under page_cgroup lock: between them, they make all uses |
| * of pc->mem_cgroup safe. |
| */ |
| if (!PageLRU(page) && !PageCgroupUsed(pc) && memcg != root_mem_cgroup) |
| pc->mem_cgroup = memcg = root_mem_cgroup; |
| |
| mz = page_cgroup_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); |
| } |
| |
| /* |
| * Checks whether given mem is same or in the root_mem_cgroup's |
| * hierarchy subtree |
| */ |
| bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, |
| struct mem_cgroup *memcg) |
| { |
| if (root_memcg == memcg) |
| return true; |
| if (!root_memcg->use_hierarchy || !memcg) |
| return false; |
| return css_is_ancestor(&memcg->css, &root_memcg->css); |
| } |
| |
| static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, |
| struct mem_cgroup *memcg) |
| { |
| bool ret; |
| |
| rcu_read_lock(); |
| ret = __mem_cgroup_same_or_subtree(root_memcg, memcg); |
| rcu_read_unlock(); |
| return ret; |
| } |
| |
| bool task_in_mem_cgroup(struct task_struct *task, |
| const struct mem_cgroup *memcg) |
| { |
| struct mem_cgroup *curr = NULL; |
| struct task_struct *p; |
| bool ret; |
| |
| p = find_lock_task_mm(task); |
| if (p) { |
| curr = try_get_mem_cgroup_from_mm(p->mm); |
| task_unlock(p); |
| } else { |
| /* |
| * All threads may have already detached their mm's, but the oom |
| * killer still needs to detect if they have already been oom |
| * killed to prevent needlessly killing additional tasks. |
| */ |
| rcu_read_lock(); |
| curr = mem_cgroup_from_task(task); |
| if (curr) |
| css_get(&curr->css); |
| rcu_read_unlock(); |
| } |
| if (!curr) |
| return false; |
| /* |
| * We should check use_hierarchy of "memcg" not "curr". Because checking |
| * use_hierarchy of "curr" here make this function true if hierarchy is |
| * enabled in "curr" and "curr" is a child of "memcg" in *cgroup* |
| * hierarchy(even if use_hierarchy is disabled in "memcg"). |
| */ |
| ret = mem_cgroup_same_or_subtree(memcg, curr); |
| css_put(&curr->css); |
| return ret; |
| } |
| |
| int mem_cgroup_inactive_anon_is_low(struct 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; |
| } |
| |
| #define mem_cgroup_from_res_counter(counter, member) \ |
| container_of(counter, struct mem_cgroup, member) |
| |
| /** |
| * mem_cgroup_margin - calculate chargeable space of a memory cgroup |
| * @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 long margin; |
| |
| margin = res_counter_margin(&memcg->res); |
| if (do_swap_account) |
| margin = min(margin, res_counter_margin(&memcg->memsw)); |
| return margin >> PAGE_SHIFT; |
| } |
| |
| int mem_cgroup_swappiness(struct mem_cgroup *memcg) |
| { |
| /* root ? */ |
| if (!css_parent(&memcg->css)) |
| return vm_swappiness; |
| |
| return memcg->swappiness; |
| } |
| |
| /* |
| * memcg->moving_account is used for checking possibility that some thread is |
| * calling move_account(). When a thread on CPU-A starts moving pages under |
| * a memcg, other threads should check memcg->moving_account under |
| * rcu_read_lock(), like this: |
| * |
| * CPU-A CPU-B |
| * rcu_read_lock() |
| * memcg->moving_account+1 if (memcg->mocing_account) |
| * take heavy locks. |
| * synchronize_rcu() update something. |
| * rcu_read_unlock() |
| * start move here. |
| */ |
| |
| /* for quick checking without looking up memcg */ |
| atomic_t memcg_moving __read_mostly; |
| |
| static void mem_cgroup_start_move(struct mem_cgroup *memcg) |
| { |
| atomic_inc(&memcg_moving); |
| atomic_inc(&memcg->moving_account); |
| synchronize_rcu(); |
| } |
| |
| static void mem_cgroup_end_move(struct mem_cgroup *memcg) |
| { |
| /* |
| * Now, mem_cgroup_clear_mc() may call this function with NULL. |
| * We check NULL in callee rather than caller. |
| */ |
| if (memcg) { |
| atomic_dec(&memcg_moving); |
| atomic_dec(&memcg->moving_account); |
| } |
| } |
| |
| /* |
| * 2 routines for checking "mem" is under move_account() or not. |
| * |
| * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This |
| * is used for avoiding races in accounting. If true, |
| * pc->mem_cgroup may be overwritten. |
| * |
| * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or |
| * under hierarchy of moving cgroups. This is for |
| * waiting at hith-memory prressure caused by "move". |
| */ |
| |
| static bool mem_cgroup_stolen(struct mem_cgroup *memcg) |
| { |
| VM_BUG_ON(!rcu_read_lock_held()); |
| return atomic_read(&memcg->moving_account) > 0; |
| } |
| |
| static bool mem_cgroup_under_move(struct mem_cgroup *memcg) |
| { |
| struct mem_cgroup *from; |
| struct mem_cgroup *to; |
| bool ret = false; |
| /* |
| * Unlike task_move routines, we access mc.to, mc.from not under |
| * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. |
| */ |
| spin_lock(&mc.lock); |
| from = mc.from; |
| to = mc.to; |
| if (!from) |
| goto unlock; |
| |
| ret = mem_cgroup_same_or_subtree(memcg, from) |
| || mem_cgroup_same_or_subtree(memcg, to); |
| unlock: |
| spin_unlock(&mc.lock); |
| return ret; |
| } |
| |
| static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) |
| { |
| if (mc.moving_task && current != mc.moving_task) { |
| if (mem_cgroup_under_move(memcg)) { |
| DEFINE_WAIT(wait); |
| prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); |
| /* moving charge context might have finished. */ |
| if (mc.moving_task) |
| schedule(); |
| finish_wait(&mc.waitq, &wait); |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| /* |
| * Take this lock when |
| * - a code tries to modify page's memcg while it's USED. |
| * - a code tries to modify page state accounting in a memcg. |
| * see mem_cgroup_stolen(), too. |
| */ |
| static void move_lock_mem_cgroup(struct mem_cgroup *memcg, |
| unsigned long *flags) |
| { |
| spin_lock_irqsave(&memcg->move_lock, *flags); |
| } |
| |
| static void move_unlock_mem_cgroup(struct mem_cgroup *memcg, |
| unsigned long *flags) |
| { |
| spin_unlock_irqrestore(&memcg->move_lock, *flags); |
| } |
| |
| #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) |
| { |
| struct cgroup *task_cgrp; |
| struct cgroup *mem_cgrp; |
| /* |
| * Need a buffer in BSS, can't rely on allocations. The code relies |
| * on the assumption that OOM is serialized for memory controller. |
| * If this assumption is broken, revisit this code. |
| */ |
| static char memcg_name[PATH_MAX]; |
| int ret; |
| struct mem_cgroup *iter; |
| unsigned int i; |
| |
| if (!p) |
| return; |
| |
| rcu_read_lock(); |
| |
| mem_cgrp = memcg->css.cgroup; |
| task_cgrp = task_cgroup(p, mem_cgroup_subsys_id); |
| |
| ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX); |
| if (ret < 0) { |
| /* |
| * Unfortunately, we are unable to convert to a useful name |
| * But we'll still print out the usage information |
| */ |
| rcu_read_unlock(); |
| goto done; |
| } |
| rcu_read_unlock(); |
| |
| pr_info("Task in %s killed", memcg_name); |
| |
| rcu_read_lock(); |
| ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX); |
| if (ret < 0) { |
| rcu_read_unlock(); |
| goto done; |
| } |
| rcu_read_unlock(); |
| |
| /* |
| * Continues from above, so we don't need an KERN_ level |
| */ |
| pr_cont(" as a result of limit of %s\n", memcg_name); |
| done: |
| |
| pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n", |
| res_counter_read_u64(&memcg->res, RES_USAGE) >> 10, |
| res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10, |
| res_counter_read_u64(&memcg->res, RES_FAILCNT)); |
| pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n", |
| res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10, |
| res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10, |
| res_counter_read_u64(&memcg->memsw, RES_FAILCNT)); |
| pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n", |
| res_counter_read_u64(&memcg->kmem, RES_USAGE) >> 10, |
| res_counter_read_u64(&memcg->kmem, RES_LIMIT) >> 10, |
| res_counter_read_u64(&memcg->kmem, RES_FAILCNT)); |
| |
| for_each_mem_cgroup_tree(iter, memcg) { |
| pr_info("Memory cgroup stats"); |
| |
| rcu_read_lock(); |
| ret = cgroup_path(iter->css.cgroup, memcg_name, PATH_MAX); |
| if (!ret) |
| pr_cont(" for %s", memcg_name); |
| rcu_read_unlock(); |
| 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"); |
| } |
| } |
| |
| /* |
| * 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 u64 mem_cgroup_get_limit(struct mem_cgroup *memcg) |
| { |
| u64 limit; |
| |
| limit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
| |
| /* |
| * Do not consider swap space if we cannot swap due to swappiness |
| */ |
| if (mem_cgroup_swappiness(memcg)) { |
| u64 memsw; |
| |
| limit += total_swap_pages << PAGE_SHIFT; |
| memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
| |
| /* |
| * If memsw is finite and limits the amount of swap space |
| * available to this memcg, return that limit. |
| */ |
| limit = min(limit, memsw); |
| } |
| |
| 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) || current->flags & PF_EXITING) { |
| set_thread_flag(TIF_MEMDIE); |
| return; |
| } |
| |
| check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL); |
| totalpages = mem_cgroup_get_limit(memcg) >> PAGE_SHIFT ? : 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 > chosen_points) { |
| 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"); |
| } |
| |
| static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg, |
| gfp_t gfp_mask, |
| unsigned long flags) |
| { |
| unsigned long total = 0; |
| bool noswap = false; |
| int loop; |
| |
| if (flags & MEM_CGROUP_RECLAIM_NOSWAP) |
| noswap = true; |
| if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum) |
| noswap = true; |
| |
| for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) { |
| if (loop) |
| drain_all_stock_async(memcg); |
| total += try_to_free_mem_cgroup_pages(memcg, gfp_mask, noswap); |
| /* |
| * Allow limit shrinkers, which are triggered directly |
| * by userspace, to catch signals and stop reclaim |
| * after minimal progress, regardless of the margin. |
| */ |
| if (total && (flags & MEM_CGROUP_RECLAIM_SHRINK)) |
| break; |
| if (mem_cgroup_margin(memcg)) |
| break; |
| /* |
| * If nothing was reclaimed after two attempts, there |
| * may be no reclaimable pages in this hierarchy. |
| */ |
| if (loop && !total) |
| break; |
| } |
| return total; |
| } |
| |
| /** |
| * test_mem_cgroup_node_reclaimable |
| * @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; |
| |
| } |
| #if MAX_NUMNODES > 1 |
| |
| /* |
| * Always updating the nodemask is not very good - even if we have an empty |
| * list or the wrong list here, we can start from some node and traverse all |
| * nodes based on the zonelist. So update the list loosely once per 10 secs. |
| * |
| */ |
| static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg) |
| { |
| int nid; |
| /* |
| * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET |
| * pagein/pageout changes since the last update. |
| */ |
| if (!atomic_read(&memcg->numainfo_events)) |
| return; |
| if (atomic_inc_return(&memcg->numainfo_updating) > 1) |
| return; |
| |
| /* make a nodemask where this memcg uses memory from */ |
| memcg->scan_nodes = node_states[N_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; |
| } |
| |
| /* |
| * Check all nodes whether it contains reclaimable pages or not. |
| * For quick scan, we make use of scan_nodes. This will allow us to skip |
| * unused nodes. But scan_nodes is lazily updated and may not cotain |
| * enough new information. We need to do double check. |
| */ |
| static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) |
| { |
| int nid; |
| |
| /* |
| * quick check...making use of scan_node. |
| * We can skip unused nodes. |
| */ |
| if (!nodes_empty(memcg->scan_nodes)) { |
| for (nid = first_node(memcg->scan_nodes); |
| nid < MAX_NUMNODES; |
| nid = next_node(nid, memcg->scan_nodes)) { |
| |
| if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) |
| return true; |
| } |
| } |
| /* |
| * Check rest of nodes. |
| */ |
| for_each_node_state(nid, N_MEMORY) { |
| if (node_isset(nid, memcg->scan_nodes)) |
| continue; |
| if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) |
| return true; |
| } |
| return false; |
| } |
| |
| #else |
| int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) |
| { |
| return 0; |
| } |
| |
| static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) |
| { |
| return test_mem_cgroup_node_reclaimable(memcg, 0, noswap); |
| } |
| #endif |
| |
| static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, |
| struct zone *zone, |
| gfp_t gfp_mask, |
| unsigned long *total_scanned) |
| { |
| struct mem_cgroup *victim = NULL; |
| int total = 0; |
| int loop = 0; |
| unsigned long excess; |
| unsigned long nr_scanned; |
| struct mem_cgroup_reclaim_cookie reclaim = { |
| .zone = zone, |
| .priority = 0, |
| }; |
| |
| excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT; |
| |
| while (1) { |
| victim = mem_cgroup_iter(root_memcg, victim, &reclaim); |
| if (!victim) { |
| loop++; |
| if (loop >= 2) { |
| /* |
| * If we have not been able to reclaim |
| * anything, it might because there are |
| * no reclaimable pages under this hierarchy |
| */ |
| if (!total) |
| break; |
| /* |
| * We want to do more targeted reclaim. |
| * excess >> 2 is not to excessive so as to |
| * reclaim too much, nor too less that we keep |
| * coming back to reclaim from this cgroup |
| */ |
| if (total >= (excess >> 2) || |
| (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) |
| break; |
| } |
| continue; |
| } |
| if (!mem_cgroup_reclaimable(victim, false)) |
| continue; |
| total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false, |
| zone, &nr_scanned); |
| *total_scanned += nr_scanned; |
| if (!res_counter_soft_limit_excess(&root_memcg->res)) |
| break; |
| } |
| mem_cgroup_iter_break(root_memcg, victim); |
| return total; |
| } |
| |
| 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; |
| } |
| } |
| |
| 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); |
| 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; |
| |
| /* |
| * Both of oom_wait_info->memcg and wake_memcg are stable under us. |
| * Then we can use css_is_ancestor without taking care of RCU. |
| */ |
| if (!mem_cgroup_same_or_subtree(oom_wait_memcg, wake_memcg) |
| && !mem_cgroup_same_or_subtree(wake_memcg, oom_wait_memcg)) |
| return 0; |
| return autoremove_wake_function(wait, mode, sync, arg); |
| } |
| |
| static void memcg_wakeup_oom(struct mem_cgroup *memcg) |
| { |
| 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) |
| 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; |
| } |
| |
| /* |
| * Currently used to update mapped file statistics, but the routine can be |
| * generalized to update other statistics as well. |
| * |
| * Notes: Race condition |
| * |
| * We usually use page_cgroup_lock() for accessing page_cgroup member but |
| * it tends to be costly. But considering some conditions, we doesn't need |
| * to do so _always_. |
| * |
| * Considering "charge", lock_page_cgroup() is not required because all |
| * file-stat operations happen after a page is attached to radix-tree. There |
| * are no race with "charge". |
| * |
| * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup |
| * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even |
| * if there are race with "uncharge". Statistics itself is properly handled |
| * by flags. |
| * |
| * Considering "move", this is an only case we see a race. To make the race |
| * small, we check mm->moving_account and detect there are possibility of race |
| * If there is, we take a lock. |
| */ |
| |
| void __mem_cgroup_begin_update_page_stat(struct page *page, |
| bool *locked, unsigned long *flags) |
| { |
| struct mem_cgroup *memcg; |
| struct page_cgroup *pc; |
| |
| pc = lookup_page_cgroup(page); |
| again: |
| memcg = pc->mem_cgroup; |
| if (unlikely(!memcg || !PageCgroupUsed(pc))) |
| return; |
| /* |
| * If this memory cgroup is not under account moving, we don't |
| * need to take move_lock_mem_cgroup(). Because we already hold |
| * rcu_read_lock(), any calls to move_account will be delayed until |
| * rcu_read_unlock() if mem_cgroup_stolen() == true. |
| */ |
| if (!mem_cgroup_stolen(memcg)) |
| return; |
| |
| move_lock_mem_cgroup(memcg, flags); |
| if (memcg != pc->mem_cgroup || !PageCgroupUsed(pc)) { |
| move_unlock_mem_cgroup(memcg, flags); |
| goto again; |
| } |
| *locked = true; |
| } |
| |
| void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags) |
| { |
| struct page_cgroup *pc = lookup_page_cgroup(page); |
| |
| /* |
| * It's guaranteed that pc->mem_cgroup never changes while |
| * lock is held because a routine modifies pc->mem_cgroup |
| * should take move_lock_mem_cgroup(). |
| */ |
| move_unlock_mem_cgroup(pc->mem_cgroup, flags); |
| } |
| |
| void mem_cgroup_update_page_stat(struct page *page, |
| enum mem_cgroup_stat_index idx, int val) |
| { |
| struct mem_cgroup *memcg; |
| struct page_cgroup *pc = lookup_page_cgroup(page); |
| unsigned long uninitialized_var(flags); |
| |
| if (mem_cgroup_disabled()) |
| return; |
| |
| VM_BUG_ON(!rcu_read_lock_held()); |
| memcg = pc->mem_cgroup; |
| if (unlikely(!memcg || !PageCgroupUsed(pc))) |
| return; |
| |
| 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 = true; |
| |
| if (nr_pages > CHARGE_BATCH) |
| return false; |
| |
| stock = &get_cpu_var(memcg_stock); |
| if (memcg == stock->cached && stock->nr_pages >= nr_pages) |
| stock->nr_pages -= nr_pages; |
| else /* need to call res_counter_charge */ |
| ret = false; |
| put_cpu_var(memcg_stock); |
| return ret; |
| } |
| |
| /* |
| * Returns stocks cached in percpu to res_counter and reset cached information. |
| */ |
| static void drain_stock(struct memcg_stock_pcp *stock) |
| { |
| struct mem_cgroup *old = stock->cached; |
| |
| if (stock->nr_pages) { |
| unsigned long bytes = stock->nr_pages * PAGE_SIZE; |
| |
| res_counter_uncharge(&old->res, bytes); |
| if (do_swap_account) |
| res_counter_uncharge(&old->memsw, bytes); |
| stock->nr_pages = 0; |
| } |
| stock->cached = NULL; |
| } |
| |
| /* |
| * This must be called under preempt disabled or must be called by |
| * a thread which is pinned to local cpu. |
| */ |
| static void drain_local_stock(struct work_struct *dummy) |
| { |
| struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock); |
| drain_stock(stock); |
| clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); |
| } |
| |
| static void __init memcg_stock_init(void) |
| { |
| int cpu; |
| |
| for_each_possible_cpu(cpu) { |
| struct memcg_stock_pcp *stock = |
| &per_cpu(memcg_stock, cpu); |
| INIT_WORK(&stock->work, drain_local_stock); |
| } |
| } |
| |
| /* |
| * Cache charges(val) which is from res_counter, to local per_cpu area. |
| * This will be consumed by consume_stock() function, later. |
| */ |
| static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) |
| { |
| struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); |
| |
| if (stock->cached != memcg) { /* reset if necessary */ |
| drain_stock(stock); |
| stock->cached = memcg; |
| } |
| stock->nr_pages += nr_pages; |
| put_cpu_var(memcg_stock); |
| } |
| |
| /* |
| * Drains all per-CPU charge caches for given root_memcg resp. subtree |
| * of the hierarchy under it. sync flag says whether we should block |
| * until the work is done. |
| */ |
| static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync) |
| { |
| int cpu, curcpu; |
| |
| /* Notify other cpus that system-wide "drain" is running */ |
| get_online_cpus(); |
| curcpu = get_cpu(); |
| for_each_online_cpu(cpu) { |
| struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); |
| struct mem_cgroup *memcg; |
| |
| memcg = stock->cached; |
| if (!memcg || !stock->nr_pages) |
| continue; |
| if (!mem_cgroup_same_or_subtree(root_memcg, memcg)) |
| continue; |
| if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { |
| if (cpu == curcpu) |
| drain_local_stock(&stock->work); |
| else |
| schedule_work_on(cpu, &stock->work); |
| } |
| } |
| put_cpu(); |
| |
| if (!sync) |
| goto out; |
| |
| for_each_online_cpu(cpu) { |
| struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); |
| if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) |
| flush_work(&stock->work); |
| } |
| out: |
| put_online_cpus(); |
| } |
| |
| /* |
| * Tries to drain stocked charges in other cpus. This function is asynchronous |
| * and just put a work per cpu for draining localy on each cpu. Caller can |
| * expects some charges will be back to res_counter later but cannot wait for |
| * it. |
| */ |
| static void drain_all_stock_async(struct mem_cgroup *root_memcg) |
| { |
| /* |
| * If someone calls draining, avoid adding more kworker runs. |
| */ |
| if (!mutex_trylock(&percpu_charge_mutex)) |
| return; |
| drain_all_stock(root_memcg, false); |
| mutex_unlock(&percpu_charge_mutex); |
| } |
| |
| /* This is a synchronous drain interface. */ |
| static void drain_all_stock_sync(struct mem_cgroup *root_memcg) |
| { |
| /* called when force_empty is called */ |
| mutex_lock(&percpu_charge_mutex); |
| drain_all_stock(root_memcg, true); |
| mutex_unlock(&percpu_charge_mutex); |
| } |
| |
| /* |
| * This function drains percpu counter value from DEAD cpu and |
| * move it to local cpu. Note that this function can be preempted. |
| */ |
| static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu) |
| { |
| int i; |
| |
| spin_lock(&memcg->pcp_counter_lock); |
| for (i = 0; i < MEM_CGROUP_STAT_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; |
| } |
| |
| |
| /* See __mem_cgroup_try_charge() for details */ |
| enum { |
| CHARGE_OK, /* success */ |
| CHARGE_RETRY, /* need to retry but retry is not bad */ |
| CHARGE_NOMEM, /* we can't do more. return -ENOMEM */ |
| CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */ |
| }; |
| |
| static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, |
| unsigned int nr_pages, unsigned int min_pages, |
| bool invoke_oom) |
| { |
| unsigned long csize = nr_pages * PAGE_SIZE; |
| struct mem_cgroup *mem_over_limit; |
| struct res_counter *fail_res; |
| unsigned long flags = 0; |
| int ret; |
| |
| ret = res_counter_charge(&memcg->res, csize, &fail_res); |
| |
| if (likely(!ret)) { |
| if (!do_swap_account) |
| return CHARGE_OK; |
| ret = res_counter_charge(&memcg->memsw, csize, &fail_res); |
| if (likely(!ret)) |
| return CHARGE_OK; |
| |
| res_counter_uncharge(&memcg->res, csize); |
| mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw); |
| flags |= MEM_CGROUP_RECLAIM_NOSWAP; |
| } else |
| mem_over_limit = mem_cgroup_from_res_counter(fail_res, res); |
| /* |
| * Never reclaim on behalf of optional batching, retry with a |
| * single page instead. |
| */ |
| if (nr_pages > min_pages) |
| return CHARGE_RETRY; |
| |
| if (!(gfp_mask & __GFP_WAIT)) |
| return CHARGE_WOULDBLOCK; |
| |
| if (gfp_mask & __GFP_NORETRY) |
| return CHARGE_NOMEM; |
| |
| ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags); |
| if (mem_cgroup_margin(mem_over_limit) >= nr_pages) |
| return CHARGE_RETRY; |
| /* |
| * Even though the limit is exceeded at this point, reclaim |
| * may have been able to free some pages. Retry the charge |
| * before killing the task. |
| * |
| * Only for regular pages, though: huge pages are rather |
| * unlikely to succeed so close to the limit, and we fall back |
| * to regular pages anyway in case of failure. |
| */ |
| if (nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER) && ret) |
| return CHARGE_RETRY; |
| |
| /* |
| * At task move, charge accounts can be doubly counted. So, it's |
| * better to wait until the end of task_move if something is going on. |
| */ |
| if (mem_cgroup_wait_acct_move(mem_over_limit)) |
| return CHARGE_RETRY; |
| |
| if (invoke_oom) |
| mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(csize)); |
| |
| return CHARGE_NOMEM; |
| } |
| |
| /* |
| * __mem_cgroup_try_charge() does |
| * 1. detect memcg to be charged against from passed *mm and *ptr, |
| * 2. update res_counter |
| * 3. call memory reclaim if necessary. |
| * |
| * In some special case, if the task is fatal, fatal_signal_pending() or |
| * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup |
| * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon |
| * as possible without any hazards. 2: all pages should have a valid |
| * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg |
| * pointer, that is treated as a charge to root_mem_cgroup. |
| * |
| * So __mem_cgroup_try_charge() will return |
| * 0 ... on success, filling *ptr with a valid memcg pointer. |
| * -ENOMEM ... charge failure because of resource limits. |
| * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup. |
| * |
| * Unlike the exported interface, an "oom" parameter is added. if oom==true, |
| * the oom-killer can be invoked. |
| */ |
| static int __mem_cgroup_try_charge(struct mm_struct *mm, |
| gfp_t gfp_mask, |
| unsigned int nr_pages, |
| struct mem_cgroup **ptr, |
| bool oom) |
| { |
| unsigned int batch = max(CHARGE_BATCH, nr_pages); |
| int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; |
| struct mem_cgroup *memcg = NULL; |
| int ret; |
| |
| /* |
| * Unlike gloval-vm's OOM-kill, we're not in memory shortage |
| * in system level. So, allow to go ahead dying process in addition to |
| * MEMDIE process. |
| */ |
| if (unlikely(test_thread_flag(TIF_MEMDIE) |
| || fatal_signal_pending(current))) |
| goto bypass; |
| |
| if (unlikely(task_in_memcg_oom(current))) |
| goto bypass; |
| |
| /* |
| * We always charge the cgroup the mm_struct belongs to. |
| * The mm_struct's mem_cgroup changes on task migration if the |
| * thread group leader migrates. It's possible that mm is not |
| * set, if so charge the root memcg (happens for pagecache usage). |
| */ |
| if (!*ptr && !mm) |
| *ptr = root_mem_cgroup; |
| again: |
| if (*ptr) { /* css should be a valid one */ |
| memcg = *ptr; |
| if (mem_cgroup_is_root(memcg)) |
| goto done; |
| if (consume_stock(memcg, nr_pages)) |
| goto done; |
| css_get(&memcg->css); |
| } else { |
| struct task_struct *p; |
| |
| rcu_read_lock(); |
| p = rcu_dereference(mm->owner); |
| /* |
| * Because we don't have task_lock(), "p" can exit. |
| * In that case, "memcg" can point to root or p can be NULL with |
| * race with swapoff. Then, we have small risk of mis-accouning. |
| * But such kind of mis-account by race always happens because |
| * we don't have cgroup_mutex(). It's overkill and we allo that |
| * small race, here. |
| * (*) swapoff at el will charge against mm-struct not against |
| * task-struct. So, mm->owner can be NULL. |
| */ |
| memcg = mem_cgroup_from_task(p); |
| if (!memcg) |
| memcg = root_mem_cgroup; |
| if (mem_cgroup_is_root(memcg)) { |
| rcu_read_unlock(); |
| goto done; |
| } |
| if (consume_stock(memcg, nr_pages)) { |
| /* |
| * It seems dagerous to access memcg without css_get(). |
| * But considering how consume_stok works, it's not |
| * necessary. If consume_stock success, some charges |
| * from this memcg are cached on this cpu. So, we |
| * don't need to call css_get()/css_tryget() before |
| * calling consume_stock(). |
| */ |
| rcu_read_unlock(); |
| goto done; |
| } |
| /* after here, we may be blocked. we need to get refcnt */ |
| if (!css_tryget(&memcg->css)) { |
| rcu_read_unlock(); |
| goto again; |
| } |
| rcu_read_unlock(); |
| } |
| |
| do { |
| bool invoke_oom = oom && !nr_oom_retries; |
| |
| /* If killed, bypass charge */ |
| if (fatal_signal_pending(current)) { |
| css_put(&memcg->css); |
| goto bypass; |
| } |
| |
| ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, |
| nr_pages, invoke_oom); |
| switch (ret) { |
| case CHARGE_OK: |
| break; |
| case CHARGE_RETRY: /* not in OOM situation but retry */ |
| batch = nr_pages; |
| css_put(&memcg->css); |
| memcg = NULL; |
| goto again; |
| case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */ |
| css_put(&memcg->css); |
| goto nomem; |
| case CHARGE_NOMEM: /* OOM routine works */ |
| if (!oom || invoke_oom) { |
| css_put(&memcg->css); |
| goto nomem; |
| } |
| nr_oom_retries--; |
| break; |
| } |
| } while (ret != CHARGE_OK); |
| |
| if (batch > nr_pages) |
| refill_stock(memcg, batch - nr_pages); |
| css_put(&memcg->css); |
| done: |
| *ptr = memcg; |
| return 0; |
| nomem: |
| *ptr = NULL; |
| if (gfp_mask & __GFP_NOFAIL) |
| return 0; |
| return -ENOMEM; |
| bypass: |
| *ptr = root_mem_cgroup; |
| return -EINTR; |
| } |
| |
| /* |
| * Somemtimes we have to undo a charge we got by try_charge(). |
| * This function is for that and do uncharge, put css's refcnt. |
| * gotten by try_charge(). |
| */ |
| static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg, |
| unsigned int nr_pages) |
| { |
| if (!mem_cgroup_is_root(memcg)) { |
| unsigned long bytes = nr_pages * PAGE_SIZE; |
| |
| res_counter_uncharge(&memcg->res, bytes); |
| if (do_swap_account) |
| res_counter_uncharge(&memcg->memsw, bytes); |
| } |
| } |
| |
| /* |
| * Cancel chrages in this cgroup....doesn't propagate to parent cgroup. |
| * This is useful when moving usage to parent cgroup. |
| */ |
| static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg, |
| unsigned int nr_pages) |
| { |
| unsigned long bytes = nr_pages * PAGE_SIZE; |
| |
| if (mem_cgroup_is_root(memcg)) |
| return; |
| |
| res_counter_uncharge_until(&memcg->res, memcg->res.parent, bytes); |
| if (do_swap_account) |
| res_counter_uncharge_until(&memcg->memsw, |
| memcg->memsw.parent, bytes); |
| } |
| |
| /* |
| * A helper function to get mem_cgroup from ID. must be called under |
| * rcu_read_lock(). The caller is responsible for calling css_tryget if |
| * the mem_cgroup is used for charging. (dropping refcnt from swap can be |
| * called against removed memcg.) |
| */ |
| static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) |
| { |
| struct cgroup_subsys_state *css; |
| |
| /* ID 0 is unused ID */ |
| if (!id) |
| return NULL; |
| css = css_lookup(&mem_cgroup_subsys, id); |
| if (!css) |
| return NULL; |
| return mem_cgroup_from_css(css); |
| } |
| |
| struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) |
| { |
| struct mem_cgroup *memcg = NULL; |
| struct page_cgroup *pc; |
| unsigned short id; |
| swp_entry_t ent; |
| |
| VM_BUG_ON(!PageLocked(page)); |
| |
| pc = lookup_page_cgroup(page); |
| lock_page_cgroup(pc); |
| if (PageCgroupUsed(pc)) { |
| memcg = pc->mem_cgroup; |
| if (memcg && !css_tryget(&memcg->css)) |
| memcg = NULL; |
| } else if (PageSwapCache(page)) { |
| ent.val = page_private(page); |
| id = lookup_swap_cgroup_id(ent); |
| rcu_read_lock(); |
| memcg = mem_cgroup_lookup(id); |
| if (memcg && !css_tryget(&memcg->css)) |
| memcg = NULL; |
| rcu_read_unlock(); |
| } |
| unlock_page_cgroup(pc); |
| return memcg; |
| } |
| |
| static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg, |
| struct page *page, |
| unsigned int nr_pages, |
| enum charge_type ctype, |
| bool lrucare) |
| { |
| struct page_cgroup *pc = lookup_page_cgroup(page); |
| struct zone *uninitialized_var(zone); |
| struct lruvec *lruvec; |
| bool was_on_lru = false; |
| bool anon; |
| |
| lock_page_cgroup(pc); |
| VM_BUG_ON(PageCgroupUsed(pc)); |
| /* |
| * we don't need page_cgroup_lock about tail pages, becase they are not |
| * accessed by any other context at this point. |
| */ |
| |
| /* |
| * 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) { |
| zone = page_zone(page); |
| spin_lock_irq(&zone->lru_lock); |
| if (PageLRU(page)) { |
| lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup); |
| ClearPageLRU(page); |
| del_page_from_lru_list(page, lruvec, page_lru(page)); |
| was_on_lru = true; |
| } |
| } |
| |
| pc->mem_cgroup = memcg; |
| /* |
| * We access a page_cgroup asynchronously without lock_page_cgroup(). |
| * Especially when a page_cgroup is taken from a page, pc->mem_cgroup |
| * is accessed after testing USED bit. To make pc->mem_cgroup visible |
| * before USED bit, we need memory barrier here. |
| * See mem_cgroup_add_lru_list(), etc. |
| */ |
| smp_wmb(); |
| SetPageCgroupUsed(pc); |
| |
| if (lrucare) { |
| if (was_on_lru) { |
| lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup); |
| VM_BUG_ON(PageLRU(page)); |
| SetPageLRU(page); |
| add_page_to_lru_list(page, lruvec, page_lru(page)); |
| } |
| spin_unlock_irq(&zone->lru_lock); |
| } |
| |
| if (ctype == MEM_CGROUP_CHARGE_TYPE_ANON) |
| anon = true; |
| else |
| anon = false; |
| |
| mem_cgroup_charge_statistics(memcg, page, anon, nr_pages); |
| unlock_page_cgroup(pc); |
| |
| /* |
| * "charge_statistics" updated event counter. Then, check it. |
| * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree. |
| * if they exceeds softlimit. |
| */ |
| memcg_check_events(memcg, page); |
| } |
| |
| static DEFINE_MUTEX(set_limit_mutex); |
| |
| #ifdef CONFIG_MEMCG_KMEM |
| static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg) |
| { |
| return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg) && |
| (memcg->kmem_account_flags & KMEM_ACCOUNTED_MASK); |
| } |
| |
| /* |
| * This is a bit cumbersome, but it is rarely used and avoids a backpointer |
| * in the memcg_cache_params struct. |
| */ |
| static struct kmem_cache *memcg_params_to_cache(struct memcg_cache_params *p) |
| { |
| struct kmem_cache *cachep; |
| |
| VM_BUG_ON(p->is_root_cache); |
| cachep = p->root_cache; |
| return cachep->memcg_params->memcg_caches[memcg_cache_id(p->memcg)]; |
| } |
| |
| #ifdef CONFIG_SLABINFO |
| static int mem_cgroup_slabinfo_read(struct cgroup_subsys_state *css, |
| struct cftype *cft, struct seq_file *m) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
| struct memcg_cache_params *params; |
| |
| if (!memcg_can_account_kmem(memcg)) |
| return -EIO; |
| |
| print_slabinfo_header(m); |
| |
| mutex_lock(&memcg->slab_caches_mutex); |
| list_for_each_entry(params, &memcg->memcg_slab_caches, list) |
| cache_show(memcg_params_to_cache(params), m); |
| mutex_unlock(&memcg->slab_caches_mutex); |
| |
| return 0; |
| } |
| #endif |
| |
| static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size) |
| { |
| struct res_counter *fail_res; |
| struct mem_cgroup *_memcg; |
| int ret = 0; |
| bool may_oom; |
| |
| ret = res_counter_charge(&memcg->kmem, size, &fail_res); |
| if (ret) |
| return ret; |
| |
| /* |
| * Conditions under which we can wait for the oom_killer. Those are |
| * the same conditions tested by the core page allocator |
| */ |
| may_oom = (gfp & __GFP_FS) && !(gfp & __GFP_NORETRY); |
| |
| _memcg = memcg; |
| ret = __mem_cgroup_try_charge(NULL, gfp, size >> PAGE_SHIFT, |
| &_memcg, may_oom); |
| |
| if (ret == -EINTR) { |
| /* |
| * __mem_cgroup_try_charge() chosed 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 |
| * __mem_cgroup_try_charge() above. Tasks that were already |
| * dying when the allocation triggers should have been already |
| * directed to the root cgroup in memcontrol.h |
| */ |
| res_counter_charge_nofail(&memcg->res, size, &fail_res); |
| if (do_swap_account) |
| res_counter_charge_nofail(&memcg->memsw, size, |
| &fail_res); |
| ret = 0; |
| } else if (ret) |
| res_counter_uncharge(&memcg->kmem, size); |
| |
| return ret; |
| } |
| |
| static void memcg_uncharge_kmem(struct mem_cgroup *memcg, u64 size) |
| { |
| res_counter_uncharge(&memcg->res, size); |
| if (do_swap_account) |
| res_counter_uncharge(&memcg->memsw, size); |
| |
| /* Not down to 0 */ |
| if (res_counter_uncharge(&memcg->kmem, size)) |
| return; |
| |
| /* |
| * Releases a reference taken in kmem_cgroup_css_offline in case |
| * this last uncharge is racing with the offlining code or it is |
| * outliving the memcg existence. |
| * |
| * The memory barrier imposed by test&clear is paired with the |
| * explicit one in memcg_kmem_mark_dead(). |
| */ |
| if (memcg_kmem_test_and_clear_dead(memcg)) |
| css_put(&memcg->css); |
| } |
| |
| void memcg_cache_list_add(struct mem_cgroup *memcg, struct kmem_cache *cachep) |
| { |
| if (!memcg) |
| return; |
| |
| mutex_lock(&memcg->slab_caches_mutex); |
| list_add(&cachep->memcg_params->list, &memcg->memcg_slab_caches); |
| mutex_unlock(&memcg->slab_caches_mutex); |
| } |
| |
| /* |
| * 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; |
| } |
| |
| /* |
| * This ends up being protected by the set_limit mutex, during normal |
| * operation, because that is its main call site. |
| * |
| * But when we create a new cache, we can call this as well if its parent |
| * is kmem-limited. That will have to hold set_limit_mutex as well. |
| */ |
| int memcg_update_cache_sizes(struct mem_cgroup *memcg) |
| { |
| int num, ret; |
| |
| num = ida_simple_get(&kmem_limited_groups, |
| 0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL); |
| if (num < 0) |
| return num; |
| /* |
| * After this point, kmem_accounted (that we test atomically in |
| * the beginning of this conditional), is no longer 0. This |
| * guarantees only one process will set the following boolean |
| * to true. We don't need test_and_set because we're protected |
| * by the set_limit_mutex anyway. |
| */ |
| memcg_kmem_set_activated(memcg); |
| |
| ret = memcg_update_all_caches(num+1); |
| if (ret) { |
| ida_simple_remove(&kmem_limited_groups, num); |
| memcg_kmem_clear_activated(memcg); |
| return ret; |
| } |
| |
| memcg->kmemcg_id = num; |
| INIT_LIST_HEAD(&memcg->memcg_slab_caches); |
| mutex_init(&memcg->slab_caches_mutex); |
| return 0; |
| } |
| |
| static size_t memcg_caches_array_size(int num_groups) |
| { |
| ssize_t size; |
| if (num_groups <= 0) |
| return 0; |
| |
| size = 2 * num_groups; |
| if (size < MEMCG_CACHES_MIN_SIZE) |
| size = MEMCG_CACHES_MIN_SIZE; |
| else if (size > MEMCG_CACHES_MAX_SIZE) |
| size = MEMCG_CACHES_MAX_SIZE; |
| |
| return size; |
| } |
| |
| /* |
| * We should update the current array size iff all caches updates succeed. This |
| * can only be done from the slab side. The slab mutex needs to be held when |
| * calling this. |
| */ |
| void memcg_update_array_size(int num) |
| { |
| if (num > memcg_limited_groups_array_size) |
| memcg_limited_groups_array_size = memcg_caches_array_size(num); |
| } |
| |
| static void kmem_cache_destroy_work_func(struct work_struct *w); |
| |
| int memcg_update_cache_size(struct kmem_cache *s, int num_groups) |
| { |
| struct memcg_cache_params *cur_params = s->memcg_params; |
| |
| VM_BUG_ON(s->memcg_params && !s->memcg_params->is_root_cache); |
| |
| if (num_groups > memcg_limited_groups_array_size) { |
| int i; |
| ssize_t size = memcg_caches_array_size(num_groups); |
| |
| size *= sizeof(void *); |
| size += offsetof(struct memcg_cache_params, memcg_caches); |
| |
| s->memcg_params = kzalloc(size, GFP_KERNEL); |
| if (!s->memcg_params) { |
| s->memcg_params = cur_params; |
| return -ENOMEM; |
| } |
| |
| s->memcg_params->is_root_cache = true; |
| |
| /* |
| * There is the chance it will be bigger than |
| * memcg_limited_groups_array_size, if we failed an allocation |
| * in a cache, in which case all caches updated before it, will |
| * have a bigger array. |
| * |
| * But if that is the case, the data after |
| * memcg_limited_groups_array_size is certainly unused |
| */ |
| for (i = 0; i < memcg_limited_groups_array_size; i++) { |
| if (!cur_params->memcg_caches[i]) |
| continue; |
| s->memcg_params->memcg_caches[i] = |
| cur_params->memcg_caches[i]; |
| } |
| |
| /* |
| * Ideally, we would wait until all caches succeed, and only |
| * then free the old one. But this is not worth the extra |
| * pointer per-cache we'd have to have for this. |
| * |
| * It is not a big deal if some caches are left with a size |
| * bigger than the others. And all updates will reset this |
| * anyway. |
| */ |
| kfree(cur_params); |
| } |
| return 0; |
| } |
| |
| int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s, |
| struct kmem_cache *root_cache) |
| { |
| size_t size; |
| |
| if (!memcg_kmem_enabled()) |
| return 0; |
| |
| if (!memcg) { |
| size = offsetof(struct memcg_cache_params, memcg_caches); |
| size += memcg_limited_groups_array_size * sizeof(void *); |
| } else |
| size = sizeof(struct memcg_cache_params); |
| |
| s->memcg_params = kzalloc(size, GFP_KERNEL); |
| if (!s->memcg_params) |
| return -ENOMEM; |
| |
| if (memcg) { |
| s->memcg_params->memcg = memcg; |
| s->memcg_params->root_cache = root_cache; |
| INIT_WORK(&s->memcg_params->destroy, |
| kmem_cache_destroy_work_func); |
| } else |
| s->memcg_params->is_root_cache = true; |
| |
| return 0; |
| } |
| |
| void memcg_release_cache(struct kmem_cache *s) |
| { |
| struct kmem_cache *root; |
| struct mem_cgroup *memcg; |
| int id; |
| |
| /* |
| * This happens, for instance, when a root cache goes away before we |
| * add any memcg. |
| */ |
| if (!s->memcg_params) |
| return; |
| |
| if (s->memcg_params->is_root_cache) |
| goto out; |
| |
| memcg = s->memcg_params->memcg; |
| id = memcg_cache_id(memcg); |
| |
| root = s->memcg_params->root_cache; |
| root->memcg_params->memcg_caches[id] = NULL; |
| |
| mutex_lock(&memcg->slab_caches_mutex); |
| list_del(&s->memcg_params->list); |
| mutex_unlock(&memcg->slab_caches_mutex); |
| |
| css_put(&memcg->css); |
| out: |
| kfree(s->memcg_params); |
| } |
| |
| /* |
| * During the creation a new cache, we need to disable our accounting mechanism |
| * altogether. This is true even if we are not creating, but rather just |
| * enqueing new caches to be created. |
| * |
| * This is because that process will trigger allocations; some visible, like |
| * explicit kmallocs to auxiliary data structures, name strings and internal |
| * cache structures; some well concealed, like INIT_WORK() that can allocate |
| * objects during debug. |
| * |
| * If any allocation happens during memcg_kmem_get_cache, we will recurse back |
| * to it. This may not be a bounded recursion: since the first cache creation |
| * failed to complete (waiting on the allocation), we'll just try to create the |
| * cache again, failing at the same point. |
| * |
| * memcg_kmem_get_cache is prepared to abort after seeing a positive count of |
| * memcg_kmem_skip_account. So we enclose anything that might allocate memory |
| * inside the following two functions. |
| */ |
| static inline void memcg_stop_kmem_account(void) |
| { |
| VM_BUG_ON(!current->mm); |
| current->memcg_kmem_skip_account++; |
| } |
| |
| static inline void memcg_resume_kmem_account(void) |
| { |
| VM_BUG_ON(!current->mm); |
| current->memcg_kmem_skip_account--; |
| } |
| |
| static void kmem_cache_destroy_work_func(struct work_struct *w) |
| { |
| struct kmem_cache *cachep; |
| struct memcg_cache_params *p; |
| |
| p = container_of(w, struct memcg_cache_params, destroy); |
| |
| cachep = memcg_params_to_cache(p); |
| |
| /* |
| * If we get down to 0 after shrink, we could delete right away. |
| * However, memcg_release_pages() already puts us back in the workqueue |
| * in that case. If we proceed deleting, we'll get a dangling |
| * reference, and removing the object from the workqueue in that case |
| * is unnecessary complication. We are not a fast path. |
| * |
| * Note that this case is fundamentally different from racing with |
| * shrink_slab(): if memcg_cgroup_destroy_cache() is called in |
| * kmem_cache_shrink, not only we would be reinserting a dead cache |
| * into the queue, but doing so from inside the worker racing to |
| * destroy it. |
| * |
| * So if we aren't down to zero, we'll just schedule a worker and try |
| * again |
| */ |
| if (atomic_read(&cachep->memcg_params->nr_pages) != 0) { |
| kmem_cache_shrink(cachep); |
| if (atomic_read(&cachep->memcg_params->nr_pages) == 0) |
| return; |
| } else |
| kmem_cache_destroy(cachep); |
| } |
| |
| void mem_cgroup_destroy_cache(struct kmem_cache *cachep) |
| { |
| if (!cachep->memcg_params->dead) |
| return; |
| |
| /* |
| * There are many ways in which we can get here. |
| * |
| * We can get to a memory-pressure situation while the delayed work is |
| * still pending to run. The vmscan shrinkers can then release all |
| * cache memory and get us to destruction. If this is the case, we'll |
| * be executed twice, which is a bug (the second time will execute over |
| * bogus data). In this case, cancelling the work should be fine. |
| * |
| * But we can also get here from the worker itself, if |
| * kmem_cache_shrink is enough to shake all the remaining objects and |
| * get the page count to 0. In this case, we'll deadlock if we try to |
| * cancel the work (the worker runs with an internal lock held, which |
| * is the same lock we would hold for cancel_work_sync().) |
| * |
| * Since we can't possibly know who got us here, just refrain from |
| * running if there is already work pending |
| */ |
| if (work_pending(&cachep->memcg_params->destroy)) |
| return; |
| /* |
| * We have to defer the actual destroying to a workqueue, because |
| * we might currently be in a context that cannot sleep. |
| */ |
| schedule_work(&cachep->memcg_params->destroy); |
| } |
| |
| /* |
| * This lock protects updaters, not readers. We want readers to be as fast as |
| * they can, and they will either see NULL or a valid cache value. Our model |
| * allow them to see NULL, in which case the root memcg will be selected. |
| * |
| * We need this lock because multiple allocations to the same cache from a non |
| * will span more than one worker. Only one of them can create the cache. |
| */ |
| static DEFINE_MUTEX(memcg_cache_mutex); |
| |
| /* |
| * Called with memcg_cache_mutex held |
| */ |
| static struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg, |
| struct kmem_cache *s) |
| { |
| struct kmem_cache *new; |
| static char *tmp_name = NULL; |
| |
| lockdep_assert_held(&memcg_cache_mutex); |
| |
| /* |
| * kmem_cache_create_memcg duplicates the given name and |
| * cgroup_name for this name requires RCU context. |
| * This static temporary buffer is used to prevent from |
| * pointless shortliving allocation. |
| */ |
| if (!tmp_name) { |
| tmp_name = kmalloc(PATH_MAX, GFP_KERNEL); |
| if (!tmp_name) |
| return NULL; |
| } |
| |
| rcu_read_lock(); |
| snprintf(tmp_name, PATH_MAX, "%s(%d:%s)", s->name, |
| memcg_cache_id(memcg), cgroup_name(memcg->css.cgroup)); |
| rcu_read_unlock(); |
| |
| new = kmem_cache_create_memcg(memcg, tmp_name, s->object_size, s->align, |
| (s->flags & ~SLAB_PANIC), s->ctor, s); |
| |
| if (new) |
| new->allocflags |= __GFP_KMEMCG; |
| |
| return new; |
| } |
| |
| static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg, |
| struct kmem_cache *cachep) |
| { |
| struct kmem_cache *new_cachep; |
| int idx; |
| |
| BUG_ON(!memcg_can_account_kmem(memcg)); |
| |
| idx = memcg_cache_id(memcg); |
| |
| mutex_lock(&memcg_cache_mutex); |
| new_cachep = cachep->memcg_params->memcg_caches[idx]; |
| if (new_cachep) { |
| css_put(&memcg->css); |
| goto out; |
| } |
| |
| new_cachep = kmem_cache_dup(memcg, cachep); |
| if (new_cachep == NULL) { |
| new_cachep = cachep; |
| css_put(&memcg->css); |
| goto out; |
| } |
| |
| atomic_set(&new_cachep->memcg_params->nr_pages , 0); |
| |
| cachep->memcg_params->memcg_caches[idx] = new_cachep; |
| /* |
| * the readers won't lock, make sure everybody sees the updated value, |
| * so they won't put stuff in the queue again for no reason |
| */ |
| wmb(); |
| out: |
| mutex_unlock(&memcg_cache_mutex); |
| return new_cachep; |
| } |
| |
| void kmem_cache_destroy_memcg_children(struct kmem_cache *s) |
| { |
| struct kmem_cache *c; |
| int i; |
| |
| if (!s->memcg_params) |
| return; |
| if (!s->memcg_params->is_root_cache) |
| return; |
| |
| /* |
| * If the cache is being destroyed, we trust that there is no one else |
| * requesting objects from it. Even if there are, the sanity checks in |
| * kmem_cache_destroy should caught this ill-case. |
| * |
| * Still, we don't want anyone else freeing memcg_caches under our |
| * noses, which can happen if a new memcg comes to life. As usual, |
| * we'll take the set_limit_mutex to protect ourselves against this. |
| */ |
| mutex_lock(&set_limit_mutex); |
| for (i = 0; i < memcg_limited_groups_array_size; i++) { |
| c = s->memcg_params->memcg_caches[i]; |
| if (!c) |
| continue; |
| |
| /* |
| * We will now manually delete the caches, so to avoid races |
| * we need to cancel all pending destruction workers and |
| * proceed with destruction ourselves. |
| * |
| * kmem_cache_destroy() will call kmem_cache_shrink internally, |
| * and that could spawn the workers again: it is likely that |
| * the cache still have active pages until this very moment. |
| * This would lead us back to mem_cgroup_destroy_cache. |
| * |
| * But that will not execute at all if the "dead" flag is not |
| * set, so flip it down to guarantee we are in control. |
| */ |
| c->memcg_params->dead = false; |
| cancel_work_sync(&c->memcg_params->destroy); |
| kmem_cache_destroy(c); |
| } |
| mutex_unlock(&set_limit_mutex); |
| } |
| |
| struct create_work { |
| struct mem_cgroup *memcg; |
| struct kmem_cache *cachep; |
| struct work_struct work; |
| }; |
| |
| static void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg) |
| { |
| struct kmem_cache *cachep; |
| struct memcg_cache_params *params; |
| |
| if (!memcg_kmem_is_active(memcg)) |
| return; |
| |
| mutex_lock(&memcg->slab_caches_mutex); |
| list_for_each_entry(params, &memcg->memcg_slab_caches, list) { |
| cachep = memcg_params_to_cache(params); |
| cachep->memcg_params->dead = true; |
| schedule_work(&cachep->memcg_params->destroy); |
| } |
| mutex_unlock(&memcg->slab_caches_mutex); |
| } |
| |
| static void memcg_create_cache_work_func(struct work_struct *w) |
| { |
| struct create_work *cw; |
| |
| cw = container_of(w, struct create_work, work); |
| memcg_create_kmem_cache(cw->memcg, cw->cachep); |
| kfree(cw); |
| } |
| |
| /* |
| * Enqueue the creation of a per-memcg kmem_cache. |
| */ |
| static void __memcg_create_cache_enqueue(struct mem_cgroup *memcg, |
| struct kmem_cache *cachep) |
| { |
| struct create_work *cw; |
| |
| cw = kmalloc(sizeof(struct create_work), GFP_NOWAIT); |
| if (cw == NULL) { |
| css_put(&memcg->css); |
| return; |
| } |
| |
| cw->memcg = memcg; |
| cw->cachep = cachep; |
| |
| INIT_WORK(&cw->work, memcg_create_cache_work_func); |
| schedule_work(&cw->work); |
| } |
| |
| static void memcg_create_cache_enqueue(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_create_cache_enqueue 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. |
| */ |
| memcg_stop_kmem_account(); |
| __memcg_create_cache_enqueue(memcg, cachep); |
| memcg_resume_kmem_account(); |
| } |
| /* |
| * 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, |
| gfp_t gfp) |
| { |
| struct mem_cgroup *memcg; |
| int idx; |
| |
| VM_BUG_ON(!cachep->memcg_params); |
| VM_BUG_ON(!cachep->memcg_params->is_root_cache); |
| |
| if (!current->mm || current->memcg_kmem_skip_account) |
| return cachep; |
| |
| rcu_read_lock(); |
| memcg = mem_cgroup_from_task(rcu_dereference(current->mm->owner)); |
| |
| if (!memcg_can_account_kmem(memcg)) |
| goto out; |
| |
| idx = memcg_cache_id(memcg); |
| |
| /* |
| * barrier to mare sure we're always seeing the up to date value. The |
| * code updating memcg_caches will issue a write barrier to match this. |
| */ |
| read_barrier_depends(); |
| if (likely(cachep->memcg_params->memcg_caches[idx])) { |
| cachep = cachep->memcg_params->memcg_caches[idx]; |
| goto out; |
| } |
| |
| /* The corresponding put will be done in the workqueue. */ |
| if (!css_tryget(&memcg->css)) |
| goto out; |
| rcu_read_unlock(); |
| |
| /* |
| * 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 |
| * kmem_cache_dup, this means no further allocation could happen |
| * with the slab_mutex held. |
| * |
| * Also, because cache creation issue get_online_cpus(), this |
| * creates a lock chain: memcg_slab_mutex -> cpu_hotplug_mutex, |
| * that ends up reversed during cpu hotplug. (cpuset allocates |
| * a bunch of GFP_KERNEL memory during cpuup). Due to all that, |
| * better to defer everything. |
| */ |
| memcg_create_cache_enqueue(memcg, cachep); |
| return cachep; |
| out: |
| rcu_read_unlock(); |
| return cachep; |
| } |
| EXPORT_SYMBOL(__memcg_kmem_get_cache); |
| |
| /* |
| * 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; |
| |
| /* |
| * Disabling accounting is only relevant for some specific memcg |
| * internal allocations. Therefore we would initially not have such |
| * check here, since direct calls to the page allocator that are marked |
| * with GFP_KMEMCG only happen outside memcg core. We are mostly |
| * concerned with cache allocations, and by having this test at |
| * memcg_kmem_get_cache, we are already able to relay the allocation to |
| * the root cache and bypass the memcg cache altogether. |
| * |
| * There is one exception, though: the SLUB allocator does not create |
| * large order caches, but rather service large kmallocs directly from |
| * the page allocator. Therefore, the following sequence when backed by |
| * the SLUB allocator: |
| * |
| * memcg_stop_kmem_account(); |
| * kmalloc(<large_number>) |
| * memcg_resume_kmem_account(); |
| * |
| * would effectively ignore the fact that we should skip accounting, |
| * since it will drive us directly to this function without passing |
| * through the cache selector memcg_kmem_get_cache. Such large |
| * allocations are extremely rare but can happen, for instance, for the |
| * cache arrays. We bring this test here. |
| */ |
| if (!current->mm || current->memcg_kmem_skip_account) |
| return true; |
| |
| memcg = try_get_mem_cgroup_from_mm(current->mm); |
| |
| /* |
| * very rare case described in mem_cgroup_from_task. Unfortunately there |
| * isn't much we can do without complicating this too much, and it would |
| * be gfp-dependent anyway. Just let it go |
| */ |
| if (unlikely(!memcg)) |
| return true; |
| |
| if (!memcg_can_account_kmem(memcg)) { |
| css_put(&memcg->css); |
| return true; |
| } |
| |
| ret = memcg_charge_kmem(memcg, gfp, PAGE_SIZE << 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) |
| { |
| struct page_cgroup *pc; |
| |
| VM_BUG_ON(mem_cgroup_is_root(memcg)); |
| |
| /* The page allocation failed. Revert */ |
| if (!page) { |
| memcg_uncharge_kmem(memcg, PAGE_SIZE << order); |
| return; |
| } |
| |
| pc = lookup_page_cgroup(page); |
| lock_page_cgroup(pc); |
| pc->mem_cgroup = memcg; |
| SetPageCgroupUsed(pc); |
| unlock_page_cgroup(pc); |
| } |
| |
| void __memcg_kmem_uncharge_pages(struct page *page, int order) |
| { |
| struct mem_cgroup *memcg = NULL; |
| struct page_cgroup *pc; |
| |
| |
| pc = lookup_page_cgroup(page); |
| /* |
| * Fast unlocked return. Theoretically might have changed, have to |
| * check again after locking. |
| */ |
| if (!PageCgroupUsed(pc)) |
| return; |
| |
| lock_page_cgroup(pc); |
| if (PageCgroupUsed(pc)) { |
| memcg = pc->mem_cgroup; |
| ClearPageCgroupUsed(pc); |
| } |
| unlock_page_cgroup(pc); |
| |
| /* |
| * We trust that only if there is a memcg associated with the page, it |
| * is a valid allocation |
| */ |
| if (!memcg) |
| return; |
| |
| VM_BUG_ON(mem_cgroup_is_root(memcg)); |
| memcg_uncharge_kmem(memcg, PAGE_SIZE << order); |
| } |
| #else |
| static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg) |
| { |
| } |
| #endif /* CONFIG_MEMCG_KMEM */ |
| |
| #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
| |
| #define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION) |
| /* |
| * Because tail pages are not marked as "used", set it. We're under |
| * zone->lru_lock, 'splitting on pmd' and compound_lock. |
| * charge/uncharge will be never happen and move_account() is done under |
| * compound_lock(), so we don't have to take care of races. |
| */ |
| void mem_cgroup_split_huge_fixup(struct page *head) |
| { |
| struct page_cgroup *head_pc = lookup_page_cgroup(head); |
| struct page_cgroup *pc; |
| struct mem_cgroup *memcg; |
| int i; |
| |
| if (mem_cgroup_disabled()) |
| return; |
| |
| memcg = head_pc->mem_cgroup; |
| for (i = 1; i < HPAGE_PMD_NR; i++) { |
| pc = head_pc + i; |
| pc->mem_cgroup = memcg; |
| smp_wmb();/* see __commit_charge() */ |
| pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT; |
| } |
| __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], |
| HPAGE_PMD_NR); |
| } |
| #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
| |
| static inline |
| void mem_cgroup_move_account_page_stat(struct mem_cgroup *from, |
| struct mem_cgroup *to, |
| unsigned int nr_pages, |
| enum mem_cgroup_stat_index idx) |
| { |
| /* Update stat data for mem_cgroup */ |
| preempt_disable(); |
| WARN_ON_ONCE(from->stat->count[idx] < nr_pages); |
| __this_cpu_add(from->stat->count[idx], -nr_pages); |
| __this_cpu_add(to->stat->count[idx], nr_pages); |
| preempt_enable(); |
| } |
| |
| /** |
| * mem_cgroup_move_account - move account of the page |
| * @page: the page |
| * @nr_pages: number of regular pages (>1 for huge pages) |
| * @pc: page_cgroup of the page. |
| * @from: mem_cgroup which the page is moved from. |
| * @to: mem_cgroup which the page is moved to. @from != @to. |
| * |
| * 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 page_cgroup *pc, |
| struct mem_cgroup *from, |
| struct mem_cgroup *to) |
| { |
| unsigned long flags; |
| int ret; |
| bool anon = PageAnon(page); |
| |
| VM_BUG_ON(from == to); |
| VM_BUG_ON(PageLRU(page)); |
| /* |
| * The page is isolated from LRU. So, collapse function |
| * will not handle this page. But page splitting can happen. |
| * Do this check under compound_page_lock(). The caller should |
| * hold it. |
| */ |
| ret = -EBUSY; |
| if (nr_pages > 1 && !PageTransHuge(page)) |
| goto out; |
| |
| lock_page_cgroup(pc); |
| |
| ret = -EINVAL; |
| if (!PageCgroupUsed(pc) || pc->mem_cgroup != from) |
| goto unlock; |
| |
| move_lock_mem_cgroup(from, &flags); |
| |
| if (!anon && page_mapped(page)) |
| mem_cgroup_move_account_page_stat(from, to, nr_pages, |
| MEM_CGROUP_STAT_FILE_MAPPED); |
| |
| if (PageWriteback(page)) |
| mem_cgroup_move_account_page_stat(from, to, nr_pages, |
| MEM_CGROUP_STAT_WRITEBACK); |
| |
| mem_cgroup_charge_statistics(from, page, anon, -nr_pages); |
| |
| /* caller should have done css_get */ |
| pc->mem_cgroup = to; |
| mem_cgroup_charge_statistics(to, page, anon, nr_pages); |
| move_unlock_mem_cgroup(from, &flags); |
| ret = 0; |
| unlock: |
| unlock_page_cgroup(pc); |
| /* |
| * check events |
| */ |
| memcg_check_events(to, page); |
| memcg_check_events(from, page); |
| out: |
| return ret; |
| } |
| |
| /** |
| * mem_cgroup_move_parent - moves page to the parent group |
| * @page: the page to move |
| * @pc: page_cgroup of the page |
| * @child: page's cgroup |
| * |
| * move charges to its parent or the root cgroup if the group has no |
| * parent (aka use_hierarchy==0). |
| * Although this might fail (get_page_unless_zero, isolate_lru_page or |
| * mem_cgroup_move_account fails) the failure is always temporary and |
| * it signals a race with a page removal/uncharge or migration. In the |
| * first case the page is on the way out and it will vanish from the LRU |
| * on the next attempt and the call should be retried later. |
| * Isolation from the LRU fails only if page has been isolated from |
| * the LRU since we looked at it and that usually means either global |
| * reclaim or migration going on. The page will either get back to the |
| * LRU or vanish. |
| * Finaly mem_cgroup_move_account fails only if the page got uncharged |
| * (!PageCgroupUsed) or moved to a different group. The page will |
| * disappear in the next attempt. |
| */ |
| static int mem_cgroup_move_parent(struct page *page, |
| struct page_cgroup *pc, |
| struct mem_cgroup *child) |
| { |
| struct mem_cgroup *parent; |
| unsigned int nr_pages; |
| unsigned long uninitialized_var(flags); |
| int ret; |
| |
| VM_BUG_ON(mem_cgroup_is_root(child)); |
| |
| ret = -EBUSY; |
| if (!get_page_unless_zero(page)) |
| goto out; |
| if (isolate_lru_page(page)) |
| goto put; |
| |
| nr_pages = hpage_nr_pages(page); |
| |
| parent = parent_mem_cgroup(child); |
| /* |
| * If no parent, move charges to root cgroup. |
| */ |
| if (!parent) |
| parent = root_mem_cgroup; |
| |
| if (nr_pages > 1) { |
| VM_BUG_ON(!PageTransHuge(page)); |
| flags = compound_lock_irqsave(page); |
| } |
| |
| ret = mem_cgroup_move_account(page, nr_pages, |
| pc, child, parent); |
| if (!ret) |
| __mem_cgroup_cancel_local_charge(child, nr_pages); |
| |
| if (nr_pages > 1) |
| compound_unlock_irqrestore(page, flags); |
| putback_lru_page(page); |
| put: |
| put_page(page); |
| out: |
| return ret; |
| } |
| |
| /* |
| * Charge the memory controller for page usage. |
| * Return |
| * 0 if the charge was successful |
| * < 0 if the cgroup is over its limit |
| */ |
| static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, |
| gfp_t gfp_mask, enum charge_type ctype) |
| { |
| struct mem_cgroup *memcg = NULL; |
| unsigned int nr_pages = 1; |
| bool oom = true; |
| int ret; |
| |
| if (PageTransHuge(page)) { |
| nr_pages <<= compound_order(page); |
| VM_BUG_ON(!PageTransHuge(page)); |
| /* |
| * Never OOM-kill a process for a huge page. The |
| * fault handler will fall back to regular pages. |
| */ |
| oom = false; |
| } |
| |
| ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom); |
| if (ret == -ENOMEM) |
| return ret; |
| __mem_cgroup_commit_charge(memcg, page, nr_pages, ctype, false); |
| return 0; |
| } |
| |
| int mem_cgroup_newpage_charge(struct page *page, |
| struct mm_struct *mm, gfp_t gfp_mask) |
| { |
| if (mem_cgroup_disabled()) |
| return 0; |
| VM_BUG_ON(page_mapped(page)); |
| VM_BUG_ON(page->mapping && !PageAnon(page)); |
| VM_BUG_ON(!mm); |
| return mem_cgroup_charge_common(page, mm, gfp_mask, |
| MEM_CGROUP_CHARGE_TYPE_ANON); |
| } |
| |
| /* |
| * While swap-in, try_charge -> commit or cancel, the page is locked. |
| * And when try_charge() successfully returns, one refcnt to memcg without |
| * struct page_cgroup is acquired. This refcnt will be consumed by |
| * "commit()" or removed by "cancel()" |
| */ |
| static int __mem_cgroup_try_charge_swapin(struct mm_struct *mm, |
| struct page *page, |
| gfp_t mask, |
| struct mem_cgroup **memcgp) |
| { |
| struct mem_cgroup *memcg; |
| struct page_cgroup *pc; |
| int ret; |
| |
| pc = lookup_page_cgroup(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 (PageCgroupUsed(pc)) |
| return 0; |
| if (!do_swap_account) |
| goto charge_cur_mm; |
| memcg = try_get_mem_cgroup_from_page(page); |
| if (!memcg) |
| goto charge_cur_mm; |
| *memcgp = memcg; |
| ret = __mem_cgroup_try_charge(NULL, mask, 1, memcgp, true); |
| css_put(&memcg->css); |
| if (ret == -EINTR) |
| ret = 0; |
| return ret; |
| charge_cur_mm: |
| ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true); |
| if (ret == -EINTR) |
| ret = 0; |
| return ret; |
| } |
| |
| int mem_cgroup_try_charge_swapin(struct mm_struct *mm, struct page *page, |
| gfp_t gfp_mask, struct mem_cgroup **memcgp) |
| { |
| *memcgp = NULL; |
| if (mem_cgroup_disabled()) |
| return 0; |
| /* |
| * A racing thread's fault, or swapoff, may have already |
| * updated the pte, and even removed page from swap cache: in |
| * those cases unuse_pte()'s pte_same() test will fail; but |
| * there's also a KSM case which does need to charge the page. |
| */ |
| if (!PageSwapCache(page)) { |
| int ret; |
| |
| ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, memcgp, true); |
| if (ret == -EINTR) |
| ret = 0; |
| return ret; |
| } |
| return __mem_cgroup_try_charge_swapin(mm, page, gfp_mask, memcgp); |
| } |
| |
| void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg) |
| { |
| if (mem_cgroup_disabled()) |
| return; |
| if (!memcg) |
| return; |
| __mem_cgroup_cancel_charge(memcg, 1); |
| } |
| |
| static void |
| __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg, |
| enum charge_type ctype) |
| { |
| if (mem_cgroup_disabled()) |
| return; |
| if (!memcg) |
| return; |
| |
| __mem_cgroup_commit_charge(memcg, page, 1, ctype, true); |
| /* |
| * Now swap is on-memory. This means this page may be |
| * counted both as mem and swap....double count. |
| * Fix it by uncharging from memsw. Basically, this SwapCache is stable |
| * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page() |
| * may call delete_from_swap_cache() before reach here. |
| */ |
| if (do_swap_account && PageSwapCache(page)) { |
| swp_entry_t ent = {.val = page_private(page)}; |
| mem_cgroup_uncharge_swap(ent); |
| } |
| } |
| |
| void mem_cgroup_commit_charge_swapin(struct page *page, |
| struct mem_cgroup *memcg) |
| { |
| __mem_cgroup_commit_charge_swapin(page, memcg, |
| MEM_CGROUP_CHARGE_TYPE_ANON); |
| } |
| |
| int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, |
| gfp_t gfp_mask) |
| { |
| struct mem_cgroup *memcg = NULL; |
| enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; |
| int ret; |
| |
| if (mem_cgroup_disabled()) |
| return 0; |
| if (PageCompound(page)) |
| return 0; |
| |
| if (!PageSwapCache(page)) |
| ret = mem_cgroup_charge_common(page, mm, gfp_mask, type); |
| else { /* page is swapcache/shmem */ |
| ret = __mem_cgroup_try_charge_swapin(mm, page, |
| gfp_mask, &memcg); |
| if (!ret) |
| __mem_cgroup_commit_charge_swapin(page, memcg, type); |
| } |
| return ret; |
| } |
| |
| static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg, |
| unsigned int nr_pages, |
| const enum charge_type ctype) |
| { |
| struct memcg_batch_info *batch = NULL; |
| bool uncharge_memsw = true; |
| |
| /* If swapout, usage of swap doesn't decrease */ |
| if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) |
| uncharge_memsw = false; |
| |
| batch = ¤t->memcg_batch; |
| /* |
| * In usual, we do css_get() when we remember memcg pointer. |
| * But in this case, we keep res->usage until end of a series of |
| * uncharges. Then, it's ok to ignore memcg's refcnt. |
| */ |
| if (!batch->memcg) |
| batch->memcg = memcg; |
| /* |
| * do_batch > 0 when unmapping pages or inode invalidate/truncate. |
| * In those cases, all pages freed continuously can be expected to be in |
| * the same cgroup and we have chance to coalesce uncharges. |
| * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE) |
| * because we want to do uncharge as soon as possible. |
| */ |
| |
| if (!batch->do_batch || test_thread_flag(TIF_MEMDIE)) |
| goto direct_uncharge; |
| |
| if (nr_pages > 1) |
| goto direct_uncharge; |
| |
| /* |
| * In typical case, batch->memcg == mem. This means we can |
| * merge a series of uncharges to an uncharge of res_counter. |
| * If not, we uncharge res_counter ony by one. |
| */ |
| if (batch->memcg != memcg) |
| goto direct_uncharge; |
| /* remember freed charge and uncharge it later */ |
| batch->nr_pages++; |
| if (uncharge_memsw) |
| batch->memsw_nr_pages++; |
| return; |
| direct_uncharge: |
| res_counter_uncharge(&memcg->res, nr_pages * PAGE_SIZE); |
| if (uncharge_memsw) |
| res_counter_uncharge(&memcg->memsw, nr_pages * PAGE_SIZE); |
| if (unlikely(batch->memcg != memcg)) |
| memcg_oom_recover(memcg); |
| } |
| |
| /* |
| * uncharge if !page_mapped(page) |
| */ |
| static struct mem_cgroup * |
| __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype, |
| bool end_migration) |
| { |
| struct mem_cgroup *memcg = NULL; |
| unsigned int nr_pages = 1; |
| struct page_cgroup *pc; |
| bool anon; |
| |
| if (mem_cgroup_disabled()) |
| return NULL; |
| |
| if (PageTransHuge(page)) { |
| nr_pages <<= compound_order(page); |
| VM_BUG_ON(!PageTransHuge(page)); |
| } |
| /* |
| * Check if our page_cgroup is valid |
| */ |
| pc = lookup_page_cgroup(page); |
| if (unlikely(!PageCgroupUsed(pc))) |
| return NULL; |
| |
| lock_page_cgroup(pc); |
| |
| memcg = pc->mem_cgroup; |
| |
| if (!PageCgroupUsed(pc)) |
| goto unlock_out; |
| |
| anon = PageAnon(page); |
| |
| switch (ctype) { |
| case MEM_CGROUP_CHARGE_TYPE_ANON: |
| /* |
| * Generally PageAnon tells if it's the anon statistics to be |
| * updated; but sometimes e.g. mem_cgroup_uncharge_page() is |
| * used before page reached the stage of being marked PageAnon. |
| */ |
| anon = true; |
| /* fallthrough */ |
| case MEM_CGROUP_CHARGE_TYPE_DROP: |
| /* See mem_cgroup_prepare_migration() */ |
| if (page_mapped(page)) |
| goto unlock_out; |
| /* |
| * Pages under migration may not be uncharged. But |
| * end_migration() /must/ be the one uncharging the |
| * unused post-migration page and so it has to call |
| * here with the migration bit still set. See the |
| * res_counter handling below. |
| */ |
| if (!end_migration && PageCgroupMigration(pc)) |
| goto unlock_out; |
| break; |
| case MEM_CGROUP_CHARGE_TYPE_SWAPOUT: |
| if (!PageAnon(page)) { /* Shared memory */ |
| if (page->mapping && !page_is_file_cache(page)) |
| goto unlock_out; |
| } else if (page_mapped(page)) /* Anon */ |
| goto unlock_out; |
| break; |
| default: |
| break; |
| } |
| |
| mem_cgroup_charge_statistics(memcg, page, anon, -nr_pages); |
| |
| ClearPageCgroupUsed(pc); |
| /* |
| * pc->mem_cgroup is not cleared here. It will be accessed when it's |
| * freed from LRU. This is safe because uncharged page is expected not |
| * to be reused (freed soon). Exception is SwapCache, it's handled by |
| * special functions. |
| */ |
| |
| unlock_page_cgroup(pc); |
| /* |
| * even after unlock, we have memcg->res.usage here and this memcg |
| * will never be freed, so it's safe to call css_get(). |
| */ |
| memcg_check_events(memcg, page); |
| if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) { |
| mem_cgroup_swap_statistics(memcg, true); |
| css_get(&memcg->css); |
| } |
| /* |
| * Migration does not charge the res_counter for the |
| * replacement page, so leave it alone when phasing out the |
| * page that is unused after the migration. |
| */ |
| if (!end_migration && !mem_cgroup_is_root(memcg)) |
| mem_cgroup_do_uncharge(memcg, nr_pages, ctype); |
| |
| return memcg; |
| |
| unlock_out: |
| unlock_page_cgroup(pc); |
| return NULL; |
| } |
| |
| void mem_cgroup_uncharge_page(struct page *page) |
| { |
| /* early check. */ |
| if (page_mapped(page)) |
| return; |
| VM_BUG_ON(page->mapping && !PageAnon(page)); |
| /* |
| * If the page is in swap cache, uncharge should be deferred |
| * to the swap path, which also properly accounts swap usage |
| * and handles memcg lifetime. |
| * |
| * Note that this check is not stable and reclaim may add the |
| * page to swap cache at any time after this. However, if the |
| * page is not in swap cache by the time page->mapcount hits |
| * 0, there won't be any page table references to the swap |
| * slot, and reclaim will free it and not actually write the |
| * page to disk. |
| */ |
| if (PageSwapCache(page)) |
| return; |
| __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_ANON, false); |
| } |
| |
| void mem_cgroup_uncharge_cache_page(struct page *page) |
| { |
| VM_BUG_ON(page_mapped(page)); |
| VM_BUG_ON(page->mapping); |
| __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE, false); |
| } |
| |
| /* |
| * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate. |
| * In that cases, pages are freed continuously and we can expect pages |
| * are in the same memcg. All these calls itself limits the number of |
| * pages freed at once, then uncharge_start/end() is called properly. |
| * This may be called prural(2) times in a context, |
| */ |
| |
| void mem_cgroup_uncharge_start(void) |
| { |
| current->memcg_batch.do_batch++; |
| /* We can do nest. */ |
| if (current->memcg_batch.do_batch == 1) { |
| current->memcg_batch.memcg = NULL; |
| current->memcg_batch.nr_pages = 0; |
| current->memcg_batch.memsw_nr_pages = 0; |
| } |
| } |
| |
| void mem_cgroup_uncharge_end(void) |
| { |
| struct memcg_batch_info *batch = ¤t->memcg_batch; |
| |
| if (!batch->do_batch) |
| return; |
| |
| batch->do_batch--; |
| if (batch->do_batch) /* If stacked, do nothing. */ |
| return; |
| |
| if (!batch->memcg) |
| return; |
| /* |
| * This "batch->memcg" is valid without any css_get/put etc... |
| * bacause we hide charges behind us. |
| */ |
| if (batch->nr_pages) |
| res_counter_uncharge(&batch->memcg->res, |
| batch->nr_pages * PAGE_SIZE); |
| if (batch->memsw_nr_pages) |
| res_counter_uncharge(&batch->memcg->memsw, |
| batch->memsw_nr_pages * PAGE_SIZE); |
| memcg_oom_recover(batch->memcg); |
| /* forget this pointer (for sanity check) */ |
| batch->memcg = NULL; |
| } |
| |
| #ifdef CONFIG_SWAP |
| /* |
| * called after __delete_from_swap_cache() and drop "page" account. |
| * memcg information is recorded to swap_cgroup of "ent" |
| */ |
| void |
| mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) |
| { |
| struct mem_cgroup *memcg; |
| int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT; |
| |
| if (!swapout) /* this was a swap cache but the swap is unused ! */ |
| ctype = MEM_CGROUP_CHARGE_TYPE_DROP; |
| |
| memcg = __mem_cgroup_uncharge_common(page, ctype, false); |
| |
| /* |
| * record memcg information, if swapout && memcg != NULL, |
| * css_get() was called in uncharge(). |
| */ |
| if (do_swap_account && swapout && memcg) |
| swap_cgroup_record(ent, css_id(&memcg->css)); |
| } |
| #endif |
| |
| #ifdef CONFIG_MEMCG_SWAP |
| /* |
| * called from swap_entry_free(). remove record in swap_cgroup and |
| * uncharge "memsw" account. |
| */ |
| void mem_cgroup_uncharge_swap(swp_entry_t ent) |
| { |
| struct mem_cgroup *memcg; |
| unsigned short id; |
| |
| if (!do_swap_account) |
| return; |
| |
| id = swap_cgroup_record(ent, 0); |
| rcu_read_lock(); |
| memcg = mem_cgroup_lookup(id); |
| if (memcg) { |
| /* |
| * We uncharge this because swap is freed. |
| * This memcg can be obsolete one. We avoid calling css_tryget |
| */ |
| if (!mem_cgroup_is_root(memcg)) |
| res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
| mem_cgroup_swap_statistics(memcg, false); |
| css_put(&memcg->css); |
| } |
| rcu_read_unlock(); |
| } |
| |
| /** |
| * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. |
| * @entry: swap entry to be moved |
| * @from: mem_cgroup which the entry is moved from |
| * @to: mem_cgroup which the entry is moved to |
| * |
| * It succeeds only when the swap_cgroup's record for this entry is the same |
| * as the mem_cgroup's id of @from. |
| * |
| * Returns 0 on success, -EINVAL on failure. |
| * |
| * The caller must have charged to @to, IOW, called res_counter_charge() about |
| * both res and memsw, and called css_get(). |
| */ |
| static int mem_cgroup_move_swap_account(swp_entry_t entry, |
| struct mem_cgroup *from, struct mem_cgroup *to) |
| { |
| unsigned short old_id, new_id; |
| |
| old_id = css_id(&from->css); |
| new_id = css_id(&to->css); |
| |
| if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { |
| mem_cgroup_swap_statistics(from, false); |
| mem_cgroup_swap_statistics(to, true); |
| /* |
| * This function is only called from task migration context now. |
| * It postpones res_counter and refcount handling till the end |
| * of task migration(mem_cgroup_clear_mc()) for performance |
| * improvement. But we cannot postpone css_get(to) because if |
| * the process that has been moved to @to does swap-in, the |
| * refcount of @to might be decreased to 0. |
| * |
| * We are in attach() phase, so the cgroup is guaranteed to be |
| * alive, so we can just call css_get(). |
| */ |
| css_get(&to->css); |
| 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 |
| |
| /* |
| * Before starting migration, account PAGE_SIZE to mem_cgroup that the old |
| * page belongs to. |
| */ |
| void mem_cgroup_prepare_migration(struct page *page, struct page *newpage, |
| struct mem_cgroup **memcgp) |
| { |
| struct mem_cgroup *memcg = NULL; |
| unsigned int nr_pages = 1; |
| struct page_cgroup *pc; |
| enum charge_type ctype; |
| |
| *memcgp = NULL; |
| |
| if (mem_cgroup_disabled()) |
| return; |
| |
| if (PageTransHuge(page)) |
| nr_pages <<= compound_order(page); |
| |
| pc = lookup_page_cgroup(page); |
| lock_page_cgroup(pc); |
| if (PageCgroupUsed(pc)) { |
| memcg = pc->mem_cgroup; |
| css_get(&memcg->css); |
| /* |
| * At migrating an anonymous page, its mapcount goes down |
| * to 0 and uncharge() will be called. But, even if it's fully |
| * unmapped, migration may fail and this page has to be |
| * charged again. We set MIGRATION flag here and delay uncharge |
| * until end_migration() is called |
| * |
| * Corner Case Thinking |
| * A) |
| * When the old page was mapped as Anon and it's unmap-and-freed |
| * while migration was ongoing. |
| * If unmap finds the old page, uncharge() of it will be delayed |
| * until end_migration(). If unmap finds a new page, it's |
| * uncharged when it make mapcount to be 1->0. If unmap code |
| * finds swap_migration_entry, the new page will not be mapped |
| * and end_migration() will find it(mapcount==0). |
| * |
| * B) |
| * When the old page was mapped but migraion fails, the kernel |
| * remaps it. A charge for it is kept by MIGRATION flag even |
| * if mapcount goes down to 0. We can do remap successfully |
| * without charging it again. |
| * |
| * C) |
| * The "old" page is under lock_page() until the end of |
| * migration, so, the old page itself will not be swapped-out. |
| * If the new page is swapped out before end_migraton, our |
| * hook to usual swap-out path will catch the event. |
| */ |
| if (PageAnon(page)) |
| SetPageCgroupMigration(pc); |
| } |
| unlock_page_cgroup(pc); |
| /* |
| * If the page is not charged at this point, |
| * we return here. |
| */ |
| if (!memcg) |
| return; |
| |
| *memcgp = memcg; |
| /* |
| * We charge new page before it's used/mapped. So, even if unlock_page() |
| * is called before end_migration, we can catch all events on this new |
| * page. In the case new page is migrated but not remapped, new page's |
| * mapcount will be finally 0 and we call uncharge in end_migration(). |
| */ |
| if (PageAnon(page)) |
| ctype = MEM_CGROUP_CHARGE_TYPE_ANON; |
| else |
| ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; |
| /* |
| * The page is committed to the memcg, but it's not actually |
| * charged to the res_counter since we plan on replacing the |
| * old one and only one page is going to be left afterwards. |
| */ |
| __mem_cgroup_commit_charge(memcg, newpage, nr_pages, ctype, false); |
| } |
| |
| /* remove redundant charge if migration failed*/ |
| void mem_cgroup_end_migration(struct mem_cgroup *memcg, |
| struct page *oldpage, struct page *newpage, bool migration_ok) |
| { |
| struct page *used, *unused; |
| struct page_cgroup *pc; |
| bool anon; |
| |
| if (!memcg) |
| return; |
| |
| if (!migration_ok) { |
| used = oldpage; |
| unused = newpage; |
| } else { |
| used = newpage; |
| unused = oldpage; |
| } |
| anon = PageAnon(used); |
| __mem_cgroup_uncharge_common(unused, |
| anon ? MEM_CGROUP_CHARGE_TYPE_ANON |
| : MEM_CGROUP_CHARGE_TYPE_CACHE, |
| true); |
| css_put(&memcg->css); |
| /* |
| * We disallowed uncharge of pages under migration because mapcount |
| * of the page goes down to zero, temporarly. |
| * Clear the flag and check the page should be charged. |
| */ |
| pc = lookup_page_cgroup(oldpage); |
| lock_page_cgroup(pc); |
| ClearPageCgroupMigration(pc); |
| unlock_page_cgroup(pc); |
| |
| /* |
| * If a page is a file cache, radix-tree replacement is very atomic |
| * and we can skip this check. When it was an Anon page, its mapcount |
| * goes down to 0. But because we added MIGRATION flage, it's not |
| * uncharged yet. There are several case but page->mapcount check |
| * and USED bit check in mem_cgroup_uncharge_page() will do enough |
| * check. (see prepare_charge() also) |
| */ |
| if (anon) |
| mem_cgroup_uncharge_page(used); |
| } |
| |
| /* |
| * At replace page cache, newpage is not under any memcg but it's on |
| * LRU. So, this function doesn't touch res_counter but handles LRU |
| * in correct way. Both pages are locked so we cannot race with uncharge. |
| */ |
| void mem_cgroup_replace_page_cache(struct page *oldpage, |
| struct page *newpage) |
| { |
| struct mem_cgroup *memcg = NULL; |
| struct page_cgroup *pc; |
| enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; |
| |
| if (mem_cgroup_disabled()) |
| return; |
| |
| pc = lookup_page_cgroup(oldpage); |
| /* fix accounting on old pages */ |
| lock_page_cgroup(pc); |
| if (PageCgroupUsed(pc)) { |
| memcg = pc->mem_cgroup; |
| mem_cgroup_charge_statistics(memcg, oldpage, false, -1); |
| ClearPageCgroupUsed(pc); |
| } |
| unlock_page_cgroup(pc); |
| |
| /* |
| * When called from shmem_replace_page(), in some cases the |
| * oldpage has already been charged, and in some cases not. |
| */ |
| if (!memcg) |
| return; |
| /* |
| * Even if newpage->mapping was NULL before starting replacement, |
| * the newpage may be on LRU(or pagevec for LRU) already. We lock |
| * LRU while we overwrite pc->mem_cgroup. |
| */ |
| __mem_cgroup_commit_charge(memcg, newpage, 1, type, true); |
| } |
| |
| #ifdef CONFIG_DEBUG_VM |
| static struct page_cgroup *lookup_page_cgroup_used(struct page *page) |
| { |
| struct page_cgroup *pc; |
| |
| pc = lookup_page_cgroup(page); |
| /* |
| * Can be NULL while feeding pages into the page allocator for |
| * the first time, i.e. during boot or memory hotplug; |
| * or when mem_cgroup_disabled(). |
| */ |
| if (likely(pc) && PageCgroupUsed(pc)) |
| return pc; |
| return NULL; |
| } |
| |
| bool mem_cgroup_bad_page_check(struct page *page) |
| { |
| if (mem_cgroup_disabled()) |
| return false; |
| |
| return lookup_page_cgroup_used(page) != NULL; |
| } |
| |
| void mem_cgroup_print_bad_page(struct page *page) |
| { |
| struct page_cgroup *pc; |
| |
| pc = lookup_page_cgroup_used(page); |
| if (pc) { |
| pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n", |
| pc, pc->flags, pc->mem_cgroup); |
| } |
| } |
| #endif |
| |
| static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, |
| unsigned long long val) |
| { |
| int retry_count; |
| u64 memswlimit, memlimit; |
| int ret = 0; |
| int children = mem_cgroup_count_children(memcg); |
| u64 curusage, oldusage; |
| int enlarge; |
| |
| /* |
| * For keeping hierarchical_reclaim simple, how long we should retry |
| * is depends on callers. We set our retry-count to be function |
| * of # of children which we should visit in this loop. |
| */ |
| retry_count = MEM_CGROUP_RECLAIM_RETRIES * children; |
| |
| oldusage = res_counter_read_u64(&memcg->res, RES_USAGE); |
| |
| enlarge = 0; |
| while (retry_count) { |
| if (signal_pending(current)) { |
| ret = -EINTR; |
| break; |
| } |
| /* |
| * Rather than hide all in some function, I do this in |
| * open coded manner. You see what this really does. |
| * We have to guarantee memcg->res.limit <= memcg->memsw.limit. |
| */ |
| mutex_lock(&set_limit_mutex); |
| memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
| if (memswlimit < val) { |
| ret = -EINVAL; |
| mutex_unlock(&set_limit_mutex); |
| break; |
| } |
| |
| memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
| if (memlimit < val) |
| enlarge = 1; |
| |
| ret = res_counter_set_limit(&memcg->res, val); |
| if (!ret) { |
| if (memswlimit == val) |
| memcg->memsw_is_minimum = true; |
| else |
| memcg->memsw_is_minimum = false; |
| } |
| mutex_unlock(&set_limit_mutex); |
| |
| if (!ret) |
| break; |
| |
| mem_cgroup_reclaim(memcg, GFP_KERNEL, |
| MEM_CGROUP_RECLAIM_SHRINK); |
| curusage = res_counter_read_u64(&memcg->res, RES_USAGE); |
| /* Usage is reduced ? */ |
| if (curusage >= oldusage) |
| retry_count--; |
| else |
| oldusage = curusage; |
| } |
| if (!ret && enlarge) |
| memcg_oom_recover(memcg); |
| |
| return ret; |
| } |
| |
| static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, |
| unsigned long long val) |
| { |
| int retry_count; |
| u64 memlimit, memswlimit, oldusage, curusage; |
| int children = mem_cgroup_count_children(memcg); |
| int ret = -EBUSY; |
| int enlarge = 0; |
| |
| /* see mem_cgroup_resize_res_limit */ |
| retry_count = children * MEM_CGROUP_RECLAIM_RETRIES; |
| oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
| while (retry_count) { |
| if (signal_pending(current)) { |
| ret = -EINTR; |
| break; |
| } |
| /* |
| * Rather than hide all in some function, I do this in |
| * open coded manner. You see what this really does. |
| * We have to guarantee memcg->res.limit <= memcg->memsw.limit. |
| */ |
| mutex_lock(&set_limit_mutex); |
| memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
| if (memlimit > val) { |
| ret = -EINVAL; |
| mutex_unlock(&set_limit_mutex); |
| break; |
| } |
| memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
| if (memswlimit < val) |
| enlarge = 1; |
| ret = res_counter_set_limit(&memcg->memsw, val); |
| if (!ret) { |
| if (memlimit == val) |
| memcg->memsw_is_minimum = true; |
| else |
| memcg->memsw_is_minimum = false; |
| } |
| mutex_unlock(&set_limit_mutex); |
| |
| if (!ret) |
| break; |
| |
| mem_cgroup_reclaim(memcg, GFP_KERNEL, |
| MEM_CGROUP_RECLAIM_NOSWAP | |
| MEM_CGROUP_RECLAIM_SHRINK); |
| curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
| /* Usage is reduced ? */ |
| if (curusage >= oldusage) |
| retry_count--; |
| else |
| oldusage = curusage; |
| } |
| if (!ret && enlarge) |
| memcg_oom_recover(memcg); |
| return ret; |
| } |
| |
| unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, |
| gfp_t gfp_mask, |
| unsigned long *total_scanned) |
| { |
| unsigned long nr_reclaimed = 0; |
| struct mem_cgroup_per_zone *mz, *next_mz = NULL; |
| unsigned long reclaimed; |
| int loop = 0; |
| struct mem_cgroup_tree_per_zone *mctz; |
| unsigned long long excess; |
| unsigned long nr_scanned; |
| |
| if (order > 0) |
| return 0; |
| |
| mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone)); |
| /* |
| * This loop can run a while, specially if mem_cgroup's continuously |
| * keep exceeding their soft limit and putting the system under |
| * pressure |
| */ |
| do { |
| if (next_mz) |
| mz = next_mz; |
| else |
| mz = mem_cgroup_largest_soft_limit_node(mctz); |
| if (!mz) |
| break; |
| |
| nr_scanned = 0; |
| reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone, |
| gfp_mask, &nr_scanned); |
| nr_reclaimed += reclaimed; |
| *total_scanned += nr_scanned; |
| spin_lock(&mctz->lock); |
| |
| /* |
| * If we failed to reclaim anything from this memory cgroup |
| * it is time to move on to the next cgroup |
| */ |
| next_mz = NULL; |
| if (!reclaimed) { |
| do { |
| /* |
| * Loop until we find yet another one. |
| * |
| * By the time we get the soft_limit lock |
| * again, someone might have aded the |
| * group back on the RB tree. Iterate to |
| * make sure we get a different mem. |
| * mem_cgroup_largest_soft_limit_node returns |
| * NULL if no other cgroup is present on |
| * the tree |
| */ |
| next_mz = |
| __mem_cgroup_largest_soft_limit_node(mctz); |
| if (next_mz == mz) |
| css_put(&next_mz->memcg->css); |
| else /* next_mz == NULL or other memcg */ |
| break; |
| } while (1); |
| } |
| __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); |
| excess = res_counter_soft_limit_excess(&mz->memcg->res); |
| /* |
| * One school of thought says that we should not add |
| * back the node to the tree if reclaim returns 0. |
| * But our reclaim could return 0, simply because due |
| * to priority we are exposing a smaller subset of |
| * memory to reclaim from. Consider this as a longer |
| * term TODO. |
| */ |
| /* If excess == 0, no tree ops */ |
| __mem_cgroup_insert_exceeded(mz->memcg, mz, mctz, excess); |
| spin_unlock(&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; |
| } |
| |
| /** |
| * mem_cgroup_force_empty_list - clears LRU of a group |
| * @memcg: group to clear |
| * @node: NUMA node |
| * @zid: zone id |
| * @lru: lru to to clear |
| * |
| * Traverse a specified page_cgroup list and try to drop them all. This doesn't |
| * reclaim the pages page themselves - pages are moved to the parent (or root) |
| * group. |
| */ |
| static void mem_cgroup_force_empty_list(struct mem_cgroup *memcg, |
| int node, int zid, enum lru_list lru) |
| { |
| struct lruvec *lruvec; |
| unsigned long flags; |
| struct list_head *list; |
| struct page *busy; |
| struct zone *zone; |
| |
| zone = &NODE_DATA(node)->node_zones[zid]; |
| lruvec = mem_cgroup_zone_lruvec(zone, memcg); |
| list = &lruvec->lists[lru]; |
| |
| busy = NULL; |
| do { |
| struct page_cgroup *pc; |
| struct page *page; |
| |
| spin_lock_irqsave(&zone->lru_lock, flags); |
| if (list_empty(list)) { |
| spin_unlock_irqrestore(&zone->lru_lock, flags); |
| break; |
| } |
| page = list_entry(list->prev, struct page, lru); |
| if (busy == page) { |
| list_move(&page->lru, list); |
| busy = NULL; |
| spin_unlock_irqrestore(&zone->lru_lock, flags); |
| continue; |
| } |
| spin_unlock_irqrestore(&zone->lru_lock, flags); |
| |
| pc = lookup_page_cgroup(page); |
| |
| if (mem_cgroup_move_parent(page, pc, memcg)) { |
| /* found lock contention or "pc" is obsolete. */ |
| busy = page; |
| cond_resched(); |
| } else |
| busy = NULL; |
| } while (!list_empty(list)); |
| } |
| |
| /* |
| * make mem_cgroup's charge to be 0 if there is no task by moving |
| * all the charges and pages to the parent. |
| * This enables deleting this mem_cgroup. |
| * |
| * Caller is responsible for holding css reference on the memcg. |
| */ |
| static void mem_cgroup_reparent_charges(struct mem_cgroup *memcg) |
| { |
| int node, zid; |
| u64 usage; |
| |
| do { |
| /* This is for making all *used* pages to be on LRU. */ |
| lru_add_drain_all(); |
| drain_all_stock_sync(memcg); |
| mem_cgroup_start_move(memcg); |
| for_each_node_state(node, N_MEMORY) { |
| for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
| enum lru_list lru; |
| for_each_lru(lru) { |
| mem_cgroup_force_empty_list(memcg, |
| node, zid, lru); |
| } |
| } |
| } |
| mem_cgroup_end_move(memcg); |
| memcg_oom_recover(memcg); |
| cond_resched(); |
| |
| /* |
| * Kernel memory may not necessarily be trackable to a specific |
| * process. So they are not migrated, and therefore we can't |
| * expect their value to drop to 0 here. |
| * Having res filled up with kmem only is enough. |
| * |
| * This is a safety check because mem_cgroup_force_empty_list |
| * could have raced with mem_cgroup_replace_page_cache callers |
| * so the lru seemed empty but the page could have been added |
| * right after the check. RES_USAGE should be safe as we always |
| * charge before adding to the LRU. |
| */ |
| usage = res_counter_read_u64(&memcg->res, RES_USAGE) - |
| res_counter_read_u64(&memcg->kmem, RES_USAGE); |
| } while (usage > 0); |
| } |
| |
| /* |
| * This mainly exists for tests during the setting of set of use_hierarchy. |
| * Since this is the very setting we are changing, the current hierarchy value |
| * is meaningless |
| */ |
| static inline bool __memcg_has_children(struct mem_cgroup *memcg) |
| { |
| struct cgroup_subsys_state *pos; |
| |
| /* bounce at first found */ |
| css_for_each_child(pos, &memcg->css) |
| return true; |
| return false; |
| } |
| |
| /* |
| * Must be called with memcg_create_mutex held, unless the cgroup is guaranteed |
| * to be already dead (as in mem_cgroup_force_empty, for instance). This is |
| * from mem_cgroup_count_children(), in the sense that we don't really care how |
| * many children we have; we only need to know if we have any. It also counts |
| * any memcg without hierarchy as infertile. |
| */ |
| static inline bool memcg_has_children(struct mem_cgroup *memcg) |
| { |
| return memcg->use_hierarchy && __memcg_has_children(memcg); |
| } |
| |
| /* |
| * 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; |
| struct cgroup *cgrp = memcg->css.cgroup; |
| |
| /* returns EBUSY if there is a task or if we come here twice. */ |
| if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) |
| return -EBUSY; |
| |
| /* 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 && res_counter_read_u64(&memcg->res, RES_USAGE) > 0) { |
| int progress; |
| |
| if (signal_pending(current)) |
| return -EINTR; |
| |
| progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL, |
| false); |
| if (!progress) { |
| nr_retries--; |
| /* maybe some writeback is necessary */ |
| congestion_wait(BLK_RW_ASYNC, HZ/10); |
| } |
| |
| } |
| lru_add_drain(); |
| mem_cgroup_reparent_charges(memcg); |
| |
| return 0; |
| } |
| |
| static int mem_cgroup_force_empty_write(struct cgroup_subsys_state *css, |
| unsigned int event) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
| |
| if (mem_cgroup_is_root(memcg)) |
| return -EINVAL; |
| return mem_cgroup_force_empty(memcg); |
| } |
| |
| 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(css_parent(&memcg->css)); |
| |
| 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 mem_cgroup_recursive_stat(struct mem_cgroup *memcg, |
| enum mem_cgroup_stat_index idx) |
| { |
| struct mem_cgroup *iter; |
| long val = 0; |
| |
| /* Per-cpu values can be negative, use a signed accumulator */ |
| for_each_mem_cgroup_tree(iter, memcg) |
| val += mem_cgroup_read_stat(iter, idx); |
| |
| if (val < 0) /* race ? */ |
| val = 0; |
| return val; |
| } |
| |
| static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) |
| { |
| u64 val; |
| |
| if (!mem_cgroup_is_root(memcg)) { |
| if (!swap) |
| return res_counter_read_u64(&memcg->res, RES_USAGE); |
| else |
| return res_counter_read_u64(&memcg->memsw, RES_USAGE); |
| } |
| |
| /* |
| * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS |
| * as well as in MEM_CGROUP_STAT_RSS_HUGE. |
| */ |
| val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE); |
| val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS); |
| |
| if (swap) |
| val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAP); |
| |
| return val << PAGE_SHIFT; |
| } |
| |
| static ssize_t mem_cgroup_read(struct cgroup_subsys_state *css, |
| struct cftype *cft, struct file *file, |
| char __user *buf, size_t nbytes, loff_t *ppos) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
| char str[64]; |
| u64 val; |
| int name, len; |
| enum res_type type; |
| |
| type = MEMFILE_TYPE(cft->private); |
| name = MEMFILE_ATTR(cft->private); |
| |
| switch (type) { |
| case _MEM: |
| if (name == RES_USAGE) |
| val = mem_cgroup_usage(memcg, false); |
| else |
| val = res_counter_read_u64(&memcg->res, name); |
| break; |
| case _MEMSWAP: |
| if (name == RES_USAGE) |
| val = mem_cgroup_usage(memcg, true); |
| else |
| val = res_counter_read_u64(&memcg->memsw, name); |
| break; |
| case _KMEM: |
| val = res_counter_read_u64(&memcg->kmem, name); |
| break; |
| default: |
| BUG(); |
| } |
| |
| len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val); |
| return simple_read_from_buffer(buf, nbytes, ppos, str, len); |
| } |
| |
| static int memcg_update_kmem_limit(struct cgroup_subsys_state *css, u64 val) |
| { |
| int ret = -EINVAL; |
| #ifdef CONFIG_MEMCG_KMEM |
| struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
| /* |
| * 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); |
| mutex_lock(&set_limit_mutex); |
| if (!memcg->kmem_account_flags && val != RES_COUNTER_MAX) { |
| if (cgroup_task_count(css->cgroup) || memcg_has_children(memcg)) { |
| ret = -EBUSY; |
| goto out; |
| } |
| ret = res_counter_set_limit(&memcg->kmem, val); |
| VM_BUG_ON(ret); |
| |
| ret = memcg_update_cache_sizes(memcg); |
| if (ret) { |
| res_counter_set_limit(&memcg->kmem, RES_COUNTER_MAX); |
| goto out; |
| } |
| static_key_slow_inc(&memcg_kmem_enabled_key); |
| /* |
| * setting the active bit after the inc will guarantee no one |
| * starts accounting before all call sites are patched |
| */ |
| memcg_kmem_set_active(memcg); |
| } else |
| ret = res_counter_set_limit(&memcg->kmem, val); |
| out: |
| mutex_unlock(&set_limit_mutex); |
| mutex_unlock(&memcg_create_mutex); |
| #endif |
| return ret; |
| } |
| |
| #ifdef CONFIG_MEMCG_KMEM |
| static int memcg_propagate_kmem(struct mem_cgroup *memcg) |
| { |
| int ret = 0; |
| struct mem_cgroup *parent = parent_mem_cgroup(memcg); |
| if (!parent) |
| goto out; |
| |
| memcg->kmem_account_flags = parent->kmem_account_flags; |
| /* |
| * When that happen, we need to disable the static branch only on those |
| * memcgs that enabled it. To achieve this, we would be forced to |
| * complicate the code by keeping track of which memcgs were the ones |
| * that actually enabled limits, and which ones got it from its |
| * parents. |
| * |
| * It is a lot simpler just to do static_key_slow_inc() on every child |
| * that is accounted. |
| */ |
| if (!memcg_kmem_is_active(memcg)) |
| goto out; |
| |
| /* |
| * __mem_cgroup_free() will issue static_key_slow_dec() because this |
| * memcg is active already. If the later initialization fails then the |
| * cgroup core triggers the cleanup so we do not have to do it here. |
| */ |
| static_key_slow_inc(&memcg_kmem_enabled_key); |
| |
| mutex_lock(&set_limit_mutex); |
| memcg_stop_kmem_account(); |
| ret = memcg_update_cache_sizes(memcg); |
| memcg_resume_kmem_account(); |
| mutex_unlock(&set_limit_mutex); |
| out: |
| return ret; |
| } |
| #endif /* CONFIG_MEMCG_KMEM */ |
| |
| /* |
| * The user of this function is... |
| * RES_LIMIT. |
| */ |
| static int mem_cgroup_write(struct cgroup_subsys_state *css, struct cftype *cft, |
| const char *buffer) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
| enum res_type type; |
| int name; |
| unsigned long long val; |
| int ret; |
| |
| type = MEMFILE_TYPE(cft->private); |
| name = MEMFILE_ATTR(cft->private); |
| |
| switch (name) { |
| case RES_LIMIT: |
| if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ |
| ret = -EINVAL; |
| break; |
| } |
| /* This function does all necessary parse...reuse it */ |
| ret = res_counter_memparse_write_strategy(buffer, &val); |
| if (ret) |
| break; |
| if (type == _MEM) |
| ret = mem_cgroup_resize_limit(memcg, val); |
| else if (type == _MEMSWAP) |
| ret = mem_cgroup_resize_memsw_limit(memcg, val); |
| else if (type == _KMEM) |
| ret = memcg_update_kmem_limit(css, val); |
| else |
| return -EINVAL; |
| break; |
| case RES_SOFT_LIMIT: |
| ret = res_counter_memparse_write_strategy(buffer, &val); |
| if (ret) |
| break; |
| /* |
| * For memsw, soft limits are hard to implement in terms |
| * of semantics, for now, we support soft limits for |
| * control without swap |
| */ |
| if (type == _MEM) |
| ret = res_counter_set_soft_limit(&memcg->res, val); |
| else |
| ret = -EINVAL; |
| break; |
| default: |
| ret = -EINVAL; /* should be BUG() ? */ |
| break; |
| } |
| return ret; |
| } |
| |
| static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg, |
| unsigned long long *mem_limit, unsigned long long *memsw_limit) |
| { |
| unsigned long long min_limit, min_memsw_limit, tmp; |
| |
| min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
| min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
| if (!memcg->use_hierarchy) |
| goto out; |
| |
| while (css_parent(&memcg->css)) { |
| memcg = mem_cgroup_from_css(css_parent(&memcg->css)); |
| if (!memcg->use_hierarchy) |
| break; |
| tmp = res_counter_read_u64(&memcg->res, RES_LIMIT); |
| min_limit = min(min_limit, tmp); |
| tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
| min_memsw_limit = min(min_memsw_limit, tmp); |
| } |
| out: |
| *mem_limit = min_limit; |
| *memsw_limit = min_memsw_limit; |
| } |
| |
| static int mem_cgroup_reset(struct cgroup_subsys_state *css, unsigned int event) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
| int name; |
| enum res_type type; |
| |
| type = MEMFILE_TYPE(event); |
| name = MEMFILE_ATTR(event); |
| |
| switch (name) { |
| case RES_MAX_USAGE: |
| if (type == _MEM) |
| res_counter_reset_max(&memcg->res); |
| else if (type == _MEMSWAP) |
| res_counter_reset_max(&memcg->memsw); |
| else if (type == _KMEM) |
| res_counter_reset_max(&memcg->kmem); |
| else |
| return -EINVAL; |
| break; |
| case RES_FAILCNT: |
| if (type == _MEM) |
| res_counter_reset_failcnt(&memcg->res); |
| else if (type == _MEMSWAP) |
| res_counter_reset_failcnt(&memcg->memsw); |
| else if (type == _KMEM) |
| res_counter_reset_failcnt(&memcg->kmem); |
| else |
| return -EINVAL; |
| break; |
| } |
| |
| return 0; |
| } |
| |
| 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 >= (1 << NR_MOVE_TYPE)) |
| 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 cgroup_subsys_state *css, |
| struct cftype *cft, struct seq_file *m) |
| { |
| int nid; |
| unsigned long total_nr, file_nr, anon_nr, unevictable_nr; |
| unsigned long node_nr; |
| struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
| |
| total_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL); |
| seq_printf(m, "total=%lu", total_nr); |
| for_each_node_state(nid, N_MEMORY) { |
| node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL); |
| seq_printf(m, " N%d=%lu", nid, node_nr); |
| } |
| seq_putc(m, '\n'); |
| |
| file_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_FILE); |
| seq_printf(m, "file=%lu", file_nr); |
| for_each_node_state(nid, N_MEMORY) { |
| node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
| LRU_ALL_FILE); |
| seq_printf(m, " N%d=%lu", nid, node_nr); |
| } |
| seq_putc(m, '\n'); |
| |
| anon_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_ANON); |
| seq_printf(m, "anon=%lu", anon_nr); |
| for_each_node_state(nid, N_MEMORY) { |
| node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
| LRU_ALL_ANON); |
| seq_printf(m, " N%d=%lu", nid, node_nr); |
| } |
| seq_putc(m, '\n'); |
| |
| unevictable_nr = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE)); |
| seq_printf(m, "unevictable=%lu", unevictable_nr); |
| for_each_node_state(nid, N_MEMORY) { |
| node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, |
| BIT(LRU_UNEVICTABLE)); |
| seq_printf(m, " N%d=%lu", nid, node_nr); |
| } |
| seq_putc(m, '\n'); |
| return 0; |
| } |
| #endif /* CONFIG_NUMA */ |
| |
| static inline void mem_cgroup_lru_names_not_uptodate(void) |
| { |
| BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS); |
| } |
| |
| static int memcg_stat_show(struct cgroup_subsys_state *css, struct cftype *cft, |
| struct seq_file *m) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
| struct mem_cgroup *mi; |
| unsigned int i; |
| |
| 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 */ |
| { |
| unsigned long long limit, memsw_limit; |
| memcg_get_hierarchical_limit(memcg, &limit, &memsw_limit); |
| seq_printf(m, "hierarchical_memory_limit %llu\n", limit); |
| if (do_swap_account) |
| seq_printf(m, "hierarchical_memsw_limit %llu\n", |
| memsw_limit); |
| } |
| |
| 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 = mem_cgroup_zoneinfo(memcg, nid, 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); |
| struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css)); |
| |
| if (val > 100 || !parent) |
| return -EINVAL; |
| |
| mutex_lock(&memcg_create_mutex); |
| |
| /* If under hierarchy, only empty-root can set this value */ |
| if ((parent->use_hierarchy) || memcg_has_children(memcg)) { |
| mutex_unlock(&memcg_create_mutex); |
| return -EINVAL; |
| } |
| |
| memcg->swappiness = val; |
| |
| mutex_unlock(&memcg_create_mutex); |
| |
| return 0; |
| } |
| |
| static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) |
| { |
| struct mem_cgroup_threshold_ary *t; |
| u64 usage; |
| int i; |
| |
| rcu_read_lock(); |
| if (!swap) |
| t = rcu_dereference(memcg->thresholds.primary); |
| else |
| t = rcu_dereference(memcg->memsw_thresholds.primary); |
| |
| if (!t) |
| goto unlock; |
| |
| usage = mem_cgroup_usage(memcg, swap); |
| |
| /* |
| * current_threshold points to threshold just below 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; |
| |
| list_for_each_entry(ev, &memcg->oom_notify, list) |
| eventfd_signal(ev->eventfd, 1); |
| return 0; |
| } |
| |
| static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) |
| { |
| struct mem_cgroup *iter; |
| |
| for_each_mem_cgroup_tree(iter, memcg) |
| mem_cgroup_oom_notify_cb(iter); |
| } |
| |
| static int mem_cgroup_usage_register_event(struct cgroup_subsys_state *css, |
| struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
| struct mem_cgroup_thresholds *thresholds; |
| struct mem_cgroup_threshold_ary *new; |
| enum res_type type = MEMFILE_TYPE(cft->private); |
| u64 threshold, usage; |
| int i, size, ret; |
| |
| ret = res_counter_memparse_write_strategy(args, &threshold); |
| if (ret) |
| return ret; |
| |
| mutex_lock(&memcg->thresholds_lock); |
| |
| if (type == _MEM) |
| thresholds = &memcg->thresholds; |
| else if (type == _MEMSWAP) |
| thresholds = &memcg->memsw_thresholds; |
| else |
| BUG(); |
| |
| usage = mem_cgroup_usage(memcg, type == _MEMSWAP); |
| |
| /* Check if a threshold crossed before adding a new one */ |
| if (thresholds->primary) |
| __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
| |
| size = thresholds->primary ? thresholds->primary->size + 1 : 1; |
| |
| /* Allocate memory for new array of thresholds */ |
| new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold), |
| GFP_KERNEL); |
| if (!new) { |
| ret = -ENOMEM; |
| goto unlock; |
| } |
| new->size = size; |
| |
| /* Copy thresholds (if any) to new array */ |
| if (thresholds->primary) { |
| memcpy(new->entries, thresholds->primary->entries, (size - 1) * |
| sizeof(struct mem_cgroup_threshold)); |
| } |
| |
| /* Add new threshold */ |
| new->entries[size - 1].eventfd = eventfd; |
| new->entries[size - 1].threshold = threshold; |
| |
| /* Sort thresholds. Registering of new threshold isn't time-critical */ |
| sort(new->entries, size, sizeof(struct mem_cgroup_threshold), |
| compare_thresholds, NULL); |
| |
| /* Find current threshold */ |
| new->current_threshold = -1; |
| for (i = 0; i < size; i++) { |
| if (new->entries[i].threshold <= usage) { |
| /* |
| * new->current_threshold will not be used until |
| * rcu_assign_pointer(), so it's safe to increment |
| * it here. |
| */ |
| ++new->current_threshold; |
| } 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 void mem_cgroup_usage_unregister_event(struct cgroup_subsys_state *css, |
| struct cftype *cft, struct eventfd_ctx *eventfd) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
| struct mem_cgroup_thresholds *thresholds; |
| struct mem_cgroup_threshold_ary *new; |
| enum res_type type = MEMFILE_TYPE(cft->private); |
| u64 usage; |
| int i, j, size; |
| |
| mutex_lock(&memcg->thresholds_lock); |
| if (type == _MEM) |
| thresholds = &memcg->thresholds; |
| else if (type == _MEMSWAP) |
| thresholds = &memcg->memsw_thresholds; |
| else |
| BUG(); |
| |
| if (!thresholds->primary) |
| goto unlock; |
| |
| usage = mem_cgroup_usage(memcg, type == _MEMSWAP); |
| |
| /* Check if a threshold crossed before removing */ |
| __mem_cgroup_threshold(memcg, type == _MEMSWAP); |
| |
| /* Calculate new number of threshold */ |
| size = 0; |
| for (i = 0; i < thresholds->primary->size; i++) { |
| if (thresholds->primary->entries[i].eventfd != eventfd) |
| size++; |
| } |
| |
| new = thresholds->spare; |
| |
| /* Set thresholds array to NULL if we don't have thresholds */ |
| if (!size) { |
| kfree(new); |
| new = NULL; |
| goto swap_buffers; |
| } |
| |
| new->size = size; |
| |
| /* Copy thresholds and find current threshold */ |
| new->current_threshold = -1; |
| for (i = 0, j = 0; i < thresholds->primary->size; i++) { |
| if (thresholds->primary->entries[i].eventfd == eventfd) |
| continue; |
| |
| new->entries[j] = thresholds->primary->entries[i]; |
| if (new->entries[j].threshold <= usage) { |
| /* |
| * new->current_threshold will not be used |
| * until rcu_assign_pointer(), so it's safe to increment |
| * it here. |
| */ |
| ++new->current_threshold; |
| } |
| j++; |
| } |
| |
| swap_buffers: |
| /* Swap primary and spare array */ |
| thresholds->spare = thresholds->primary; |
| /* 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 int mem_cgroup_oom_register_event(struct cgroup_subsys_state *css, |
| struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
| struct mem_cgroup_eventfd_list *event; |
| enum res_type type = MEMFILE_TYPE(cft->private); |
| |
| BUG_ON(type != _OOM_TYPE); |
| event = kmalloc(sizeof(*event), GFP_KERNEL); |
| if (!event) |
| return -ENOMEM; |
| |
| spin_lock(&memcg_oom_lock); |
| |
| event->eventfd = eventfd; |
| list_add(&event->list, &memcg->oom_notify); |
| |
| /* already in OOM ? */ |
| if (atomic_read(&memcg->under_oom)) |
| eventfd_signal(eventfd, 1); |
| spin_unlock(&memcg_oom_lock); |
| |
| return 0; |
| } |
| |
| static void mem_cgroup_oom_unregister_event(struct cgroup_subsys_state *css, |
| struct cftype *cft, struct eventfd_ctx *eventfd) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
| struct mem_cgroup_eventfd_list *ev, *tmp; |
| enum res_type type = MEMFILE_TYPE(cft->private); |
| |
| BUG_ON(type != _OOM_TYPE); |
| |
| spin_lock(&memcg_oom_lock); |
| |
| list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { |
| if (ev->eventfd == eventfd) { |
| list_del(&ev->list); |
| kfree(ev); |
| } |
| } |
| |
| spin_unlock(&memcg_oom_lock); |
| } |
| |
| static int mem_cgroup_oom_control_read(struct cgroup_subsys_state *css, |
| struct cftype *cft, struct cgroup_map_cb *cb) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
| |
| cb->fill(cb, "oom_kill_disable", memcg->oom_kill_disable); |
| |
| if (atomic_read(&memcg->under_oom)) |
| cb->fill(cb, "under_oom", 1); |
| else |
| cb->fill(cb, "under_oom", 0); |
| return 0; |
| } |
| |
| static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css, |
| struct cftype *cft, u64 val) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
| struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css)); |
| |
| /* cannot set to root cgroup and only 0 and 1 are allowed */ |
| if (!parent || !((val == 0) || (val == 1))) |
| return -EINVAL; |
| |
| mutex_lock(&memcg_create_mutex); |
| /* oom-kill-disable is a flag for subhierarchy. */ |
| if ((parent->use_hierarchy) || memcg_has_children(memcg)) { |
| mutex_unlock(&memcg_create_mutex); |
| return -EINVAL; |
| } |
| memcg->oom_kill_disable = val; |
| if (!val) |
| memcg_oom_recover(memcg); |
| mutex_unlock(&memcg_create_mutex); |
| return 0; |
| } |
| |
| #ifdef CONFIG_MEMCG_KMEM |
| static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
| { |
| int ret; |
| |
| memcg->kmemcg_id = -1; |
| ret = memcg_propagate_kmem(memcg); |
| if (ret) |
| return ret; |
| |
| return mem_cgroup_sockets_init(memcg, ss); |
| } |
| |
| static void memcg_destroy_kmem(struct mem_cgroup *memcg) |
| { |
| mem_cgroup_sockets_destroy(memcg); |
| } |
| |
| static void kmem_cgroup_css_offline(struct mem_cgroup *memcg) |
| { |
| if (!memcg_kmem_is_active(memcg)) |
| return; |
| |
| /* |
| * kmem charges can outlive the cgroup. In the case of slab |
| * pages, for instance, a page contain objects from various |
| * processes. As we prevent from taking a reference for every |
| * such allocation we have to be careful when doing uncharge |
| * (see memcg_uncharge_kmem) and here during offlining. |
| * |
| * The idea is that that only the _last_ uncharge which sees |
| * the dead memcg will drop the last reference. An additional |
| * reference is taken here before the group is marked dead |
| * which is then paired with css_put during uncharge resp. here. |
| * |
| * Although this might sound strange as this path is called from |
| * css_offline() when the referencemight have dropped down to 0 |
| * and shouldn't be incremented anymore (css_tryget would fail) |
| * we do not have other options because of the kmem allocations |
| * lifetime. |
| */ |
| css_get(&memcg->css); |
| |
| memcg_kmem_mark_dead(memcg); |
| |
| if (res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0) |
| return; |
| |
| if (memcg_kmem_test_and_clear_dead(memcg)) |
| css_put(&memcg->css); |
| } |
| #else |
| static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) |
| { |
| return 0; |
| } |
| |
| static void memcg_destroy_kmem(struct mem_cgroup *memcg) |
| { |
| } |
| |
| static void kmem_cgroup_css_offline(struct mem_cgroup *memcg) |
| { |
| } |
| #endif |
| |
| static struct cftype mem_cgroup_files[] = { |
| { |
| .name = "usage_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
| .read = mem_cgroup_read, |
| .register_event = mem_cgroup_usage_register_event, |
| .unregister_event = mem_cgroup_usage_unregister_event, |
| }, |
| { |
| .name = "max_usage_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
| .trigger = mem_cgroup_reset, |
| .read = mem_cgroup_read, |
| }, |
| { |
| .name = "limit_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
| .write_string = mem_cgroup_write, |
| .read = mem_cgroup_read, |
| }, |
| { |
| .name = "soft_limit_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), |
| .write_string = mem_cgroup_write, |
| .read = mem_cgroup_read, |
| }, |
| { |
| .name = "failcnt", |
| .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
| .trigger = mem_cgroup_reset, |
| .read = mem_cgroup_read, |
| }, |
| { |
| .name = "stat", |
| .read_seq_string = memcg_stat_show, |
| }, |
| { |
| .name = "force_empty", |
| .trigger = mem_cgroup_force_empty_write, |
| }, |
| { |
| .name = "use_hierarchy", |
| .flags = CFTYPE_INSANE, |
| .write_u64 = mem_cgroup_hierarchy_write, |
| .read_u64 = mem_cgroup_hierarchy_read, |
| }, |
| { |
| .name = "swappiness", |
| .read_u64 = mem_cgroup_swappiness_read, |
| .write_u64 = mem_cgroup_swappiness_write, |
| }, |
| { |
| .name = "move_charge_at_immigrate", |
| .read_u64 = mem_cgroup_move_charge_read, |
| .write_u64 = mem_cgroup_move_charge_write, |
| }, |
| { |
| .name = "oom_control", |
| .read_map = mem_cgroup_oom_control_read, |
| .write_u64 = mem_cgroup_oom_control_write, |
| .register_event = mem_cgroup_oom_register_event, |
| .unregister_event = mem_cgroup_oom_unregister_event, |
| .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), |
| }, |
| { |
| .name = "pressure_level", |
| .register_event = vmpressure_register_event, |
| .unregister_event = vmpressure_unregister_event, |
| }, |
| #ifdef CONFIG_NUMA |
| { |
| .name = "numa_stat", |
| .read_seq_string = memcg_numa_stat_show, |
| }, |
| #endif |
| #ifdef CONFIG_MEMCG_KMEM |
| { |
| .name = "kmem.limit_in_bytes", |
| .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT), |
| .write_string = mem_cgroup_write, |
| .read = mem_cgroup_read, |
| }, |
| { |
| .name = "kmem.usage_in_bytes", |
| .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE), |
| .read = mem_cgroup_read, |
| }, |
| { |
| .name = "kmem.failcnt", |
| .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT), |
| .trigger = mem_cgroup_reset, |
| .read = mem_cgroup_read, |
| }, |
| { |
| .name = "kmem.max_usage_in_bytes", |
| .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE), |
| .trigger = mem_cgroup_reset, |
| .read = mem_cgroup_read, |
| }, |
| #ifdef CONFIG_SLABINFO |
| { |
| .name = "kmem.slabinfo", |
| .read_seq_string = mem_cgroup_slabinfo_read, |
| }, |
| #endif |
| #endif |
| { }, /* terminate */ |
| }; |
| |
| #ifdef CONFIG_MEMCG_SWAP |
| static struct cftype memsw_cgroup_files[] = { |
| { |
| .name = "memsw.usage_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), |
| .read = mem_cgroup_read, |
| .register_event = mem_cgroup_usage_register_event, |
| .unregister_event = mem_cgroup_usage_unregister_event, |
| }, |
| { |
| .name = "memsw.max_usage_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), |
| .trigger = mem_cgroup_reset, |
| .read = mem_cgroup_read, |
| }, |
| { |
| .name = "memsw.limit_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), |
| .write_string = mem_cgroup_write, |
| .read = mem_cgroup_read, |
| }, |
| { |
| .name = "memsw.failcnt", |
| .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), |
| .trigger = mem_cgroup_reset, |
| .read = mem_cgroup_read, |
| }, |
| { }, /* terminate */ |
| }; |
| #endif |
| static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) |
| { |
| struct mem_cgroup_per_node *pn; |
| struct mem_cgroup_per_zone *mz; |
| 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 = memcg_size(); |
| |
| /* Can be very big if nr_node_ids is very big */ |
| if (size < PAGE_SIZE) |
| memcg = kzalloc(size, GFP_KERNEL); |
| else |
| memcg = vzalloc(size); |
| |
| 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: |
| if (size < PAGE_SIZE) |
| kfree(memcg); |
| else |
| vfree(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; |
| size_t size = memcg_size(); |
| |
| mem_cgroup_remove_from_trees(memcg); |
| free_css_id(&mem_cgroup_subsys, &memcg->css); |
| |
| for_each_node(node) |
| free_mem_cgroup_per_zone_info(memcg, node); |
| |
| free_percpu(memcg->stat); |
| |
| /* |
| * We need to make sure that (at least for now), the jump label |
| * destruction code runs outside of the cgroup lock. This is because |
| * get_online_cpus(), which is called from the static_branch update, |
| * can't be called inside the cgroup_lock. cpusets are the ones |
| * enforcing this dependency, so if they ever change, we might as well. |
| * |
| * schedule_work() will guarantee this happens. Be careful if you need |
| * to move this code around, and make sure it is outside |
| * the cgroup_lock. |
| */ |
| disarm_static_keys(memcg); |
| if (size < PAGE_SIZE) |
| kfree(memcg); |
| else |
| vfree(memcg); |
| } |
| |
| /* |
| * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. |
| */ |
| struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg) |
| { |
| if (!memcg->res.parent) |
| return NULL; |
| return mem_cgroup_from_res_counter(memcg->res.parent, res); |
| } |
| EXPORT_SYMBOL(parent_mem_cgroup); |
| |
| static void __init mem_cgroup_soft_limit_tree_init(void) |
| { |
| struct mem_cgroup_tree_per_node *rtpn; |
| struct mem_cgroup_tree_per_zone *rtpz; |
| int tmp, node, zone; |
| |
| for_each_node(node) { |
| tmp = node; |
| if (!node_state(node, N_NORMAL_MEMORY)) |
| tmp = -1; |
| rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp); |
| BUG_ON(!rtpn); |
| |
| soft_limit_tree.rb_tree_per_node[node] = rtpn; |
| |
| for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
| rtpz = &rtpn->rb_tree_per_zone[zone]; |
| rtpz->rb_root = RB_ROOT; |
| spin_lock_init(&rtpz->lock); |
| } |
| } |
| } |
| |
| 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; |
| res_counter_init(&memcg->res, NULL); |
| res_counter_init(&memcg->memsw, NULL); |
| res_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); |
| |
| 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(css)); |
| int error = 0; |
| |
| 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) { |
| res_counter_init(&memcg->res, &parent->res); |
| res_counter_init(&memcg->memsw, &parent->memsw); |
| res_counter_init(&memcg->kmem, &parent->kmem); |
| |
| /* |
| * No need to take a reference to the parent because cgroup |
| * core guarantees its existence. |
| */ |
| } else { |
| res_counter_init(&memcg->res, NULL); |
| res_counter_init(&memcg->memsw, NULL); |
| res_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) |
| mem_cgroup_subsys.broken_hierarchy = true; |
| } |
| |
| error = memcg_init_kmem(memcg, &mem_cgroup_subsys); |
| mutex_unlock(&memcg_create_mutex); |
| return error; |
| } |
| |
| /* |
| * Announce all parents that a group from their hierarchy is gone. |
| */ |
| static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup *memcg) |
| { |
| struct mem_cgroup *parent = memcg; |
| |
| while ((parent = parent_mem_cgroup(parent))) |
| mem_cgroup_iter_invalidate(parent); |
| |
| /* |
| * if the root memcg is not hierarchical we have to check it |
| * explicitely. |
| */ |
| if (!root_mem_cgroup->use_hierarchy) |
| mem_cgroup_iter_invalidate(root_mem_cgroup); |
| } |
| |
| static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_css(css); |
| |
| kmem_cgroup_css_offline(memcg); |
| |
| mem_cgroup_invalidate_reclaim_iterators(memcg); |
| mem_cgroup_reparent_charges(memcg); |
| mem_cgroup_destroy_all_caches(memcg); |
| vmpressure_cleanup(&memcg->vmpressure); |
| } |
| |
| 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); |
| } |
| |
| #ifdef CONFIG_MMU |
| /* Handlers for move charge at task migration. */ |
| #define PRECHARGE_COUNT_AT_ONCE 256 |
| static int mem_cgroup_do_precharge(unsigned long count) |
| { |
| int ret = 0; |
| int batch_count = PRECHARGE_COUNT_AT_ONCE; |
| struct mem_cgroup *memcg = mc.to; |
| |
| if (mem_cgroup_is_root(memcg)) { |
| mc.precharge += count; |
| /* we don't need css_get for root */ |
| return ret; |
| } |
| /* try to charge at once */ |
| if (count > 1) { |
| struct res_counter *dummy; |
| /* |
| * "memcg" cannot be under rmdir() because we've already checked |
| * by cgroup_lock_live_cgroup() that it is not removed and we |
| * are still under the same cgroup_mutex. So we can postpone |
| * css_get(). |
| */ |
| if (res_counter_charge(&memcg->res, PAGE_SIZE * count, &dummy)) |
| goto one_by_one; |
| if (do_swap_account && res_counter_charge(&memcg->memsw, |
| PAGE_SIZE * count, &dummy)) { |
| res_counter_uncharge(&memcg->res, PAGE_SIZE * count); |
| goto one_by_one; |
| } |
| mc.precharge += count; |
| return ret; |
| } |
| one_by_one: |
| /* fall back to one by one charge */ |
| while (count--) { |
| if (signal_pending(current)) { |
| ret = -EINTR; |
| break; |
| } |
| if (!batch_count--) { |
| batch_count = PRECHARGE_COUNT_AT_ONCE; |
| cond_resched(); |
| } |
| ret = __mem_cgroup_try_charge(NULL, |
| GFP_KERNEL, 1, &memcg, false); |
| if (ret) |
| /* mem_cgroup_clear_mc() will do uncharge later */ |
| return ret; |
| mc.precharge++; |
| } |
| return ret; |
| } |
| |
| /** |
| * 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)) { |
| /* we don't move shared anon */ |
| if (!move_anon()) |
| return NULL; |
| } else if (!move_file()) |
| /* we ignore mapcount for file pages */ |
| 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 (!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 (!move_file()) |
| return NULL; |
| |
| mapping = vma->vm_file->f_mapping; |
| if (pte_none(ptent)) |
| pgoff = linear_page_index(vma, addr); |
| else /* pte_file(ptent) is true */ |
| pgoff = pte_to_pgoff(ptent); |
| |
| /* page is moved even if it's not RSS of this task(page-faulted). */ |
| page = find_get_page(mapping, pgoff); |
| |
| #ifdef CONFIG_SWAP |
| /* shmem/tmpfs may report page out on swap: account for that too. */ |
| if (radix_tree_exceptional_entry(page)) { |
| swp_entry_t swap = radix_to_swp_entry(page); |
| if (do_swap_account) |
| *entry = swap; |
| page = find_get_page(swap_address_space(swap), swap.val); |
| } |
| #endif |
| return page; |
| } |
| |
| 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; |
| struct page_cgroup *pc; |
| 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) || pte_file(ptent)) |
| page = mc_handle_file_pte(vma, addr, ptent, &ent); |
| |
| if (!page && !ent.val) |
| return ret; |
| if (page) { |
| pc = lookup_page_cgroup(page); |
| /* |
| * Do only loose check w/o page_cgroup lock. |
| * mem_cgroup_move_account() checks the pc is valid or not under |
| * the lock. |
| */ |
| if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) { |
| ret = MC_TARGET_PAGE; |
| if (target) |
| target->page = page; |
| } |
| if (!ret || !target) |
| put_page(page); |
| } |
| /* There is a swap entry and a page doesn't exist or isn't charged */ |
| if (ent.val && !ret && |
| css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) { |
| ret = MC_TARGET_SWAP; |
| if (target) |
| target->ent = ent; |
| } |
| return ret; |
| } |
| |
| #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; |
| struct page_cgroup *pc; |
| enum mc_target_type ret = MC_TARGET_NONE; |
| |
| page = pmd_page(pmd); |
| VM_BUG_ON(!page || !PageHead(page)); |
| if (!move_anon()) |
| return ret; |
| pc = lookup_page_cgroup(page); |
| if (PageCgroupUsed(pc) && pc->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->private; |
| pte_t *pte; |
| spinlock_t *ptl; |
| |
| if (pmd_trans_huge_lock(pmd, vma) == 1) { |
| if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) |
| mc.precharge += HPAGE_PMD_NR; |
| spin_unlock(&vma->vm_mm->page_table_lock); |
| 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 vm_area_struct *vma; |
| |
| down_read(&mm->mmap_sem); |
| for (vma = mm->mmap; vma; vma = vma->vm_next) { |
| struct mm_walk mem_cgroup_count_precharge_walk = { |
| .pmd_entry = mem_cgroup_count_precharge_pte_range, |
| .mm = mm, |
| .private = vma, |
| }; |
| if (is_vm_hugetlb_page(vma)) |
| continue; |
| walk_page_range(vma->vm_start, vma->vm_end, |
| &mem_cgroup_count_precharge_walk); |
| } |
| up_read(&mm->mmap_sem); |
| |
| precharge = mc.precharge; |
| mc.precharge = 0; |
| |
| return precharge; |
| } |
| |
| static int mem_cgroup_precharge_mc(struct mm_struct *mm) |
| { |
| unsigned long precharge = mem_cgroup_count_precharge(mm); |
| |
| VM_BUG_ON(mc.moving_task); |
| mc.moving_task = current; |
| return mem_cgroup_do_precharge(precharge); |
| } |
| |
| /* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ |
| static void __mem_cgroup_clear_mc(void) |
| { |
| struct mem_cgroup *from = mc.from; |
| struct mem_cgroup *to = mc.to; |
| int i; |
| |
| /* we must uncharge all the leftover precharges from mc.to */ |
| if (mc.precharge) { |
| __mem_cgroup_cancel_charge(mc.to, mc.precharge); |
| mc.precharge = 0; |
| } |
| /* |
| * we didn't uncharge from mc.from at mem_cgroup_move_account(), so |
| * we must uncharge here. |
| */ |
| if (mc.moved_charge) { |
| __mem_cgroup_cancel_charge(mc.from, mc.moved_charge); |
| mc.moved_charge = 0; |
| } |
| /* we must fixup refcnts and charges */ |
| if (mc.moved_swap) { |
| /* uncharge swap account from the old cgroup */ |
| if (!mem_cgroup_is_root(mc.from)) |
| res_counter_uncharge(&mc.from->memsw, |
| PAGE_SIZE * mc.moved_swap); |
| |
| for (i = 0; i < mc.moved_swap; i++) |
| css_put(&mc.from->css); |
| |
| if (!mem_cgroup_is_root(mc.to)) { |
| /* |
| * we charged both to->res and to->memsw, so we should |
| * uncharge to->res. |
| */ |
| res_counter_uncharge(&mc.to->res, |
| PAGE_SIZE * mc.moved_swap); |
| } |
| /* we've already done 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) |
| { |
| struct mem_cgroup *from = mc.from; |
| |
| /* |
| * we must clear moving_task before waking up waiters at the end of |
| * task migration. |
| */ |
| mc.moving_task = NULL; |
| __mem_cgroup_clear_mc(); |
| spin_lock(&mc.lock); |
| mc.from = NULL; |
| mc.to = NULL; |
| spin_unlock(&mc.lock); |
| mem_cgroup_end_move(from); |
| } |
| |
| static int mem_cgroup_can_attach(struct cgroup_subsys_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_charge_at_immigrate; |
| |
| /* |
| * 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_charge_at_immigrate = memcg->move_charge_at_immigrate; |
| if (move_charge_at_immigrate) { |
| struct mm_struct *mm; |
| struct mem_cgroup *from = mem_cgroup_from_task(p); |
| |
| VM_BUG_ON(from == memcg); |
| |
| mm = get_task_mm(p); |
| if (!mm) |
| return 0; |
| /* We move charges only when we move a owner of the mm */ |
| if (mm->owner == p) { |
| VM_BUG_ON(mc.from); |
| VM_BUG_ON(mc.to); |
| VM_BUG_ON(mc.precharge); |
| VM_BUG_ON(mc.moved_charge); |
| VM_BUG_ON(mc.moved_swap); |
| mem_cgroup_start_move(from); |
| spin_lock(&mc.lock); |
| mc.from = from; |
| mc.to = memcg; |
| mc.immigrate_flags = move_charge_at_immigrate; |
| 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) |
| { |
| mem_cgroup_clear_mc(); |
| } |
| |
| static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, |
| unsigned long addr, unsigned long end, |
| struct mm_walk *walk) |
| { |
| int ret = 0; |
| struct vm_area_struct *vma = walk->private; |
| pte_t *pte; |
| spinlock_t *ptl; |
| enum mc_target_type target_type; |
| union mc_target target; |
| struct page *page; |
| struct page_cgroup *pc; |
| |
| /* |
| * 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) == 1) { |
| if (mc.precharge < HPAGE_PMD_NR) { |
| spin_unlock(&vma->vm_mm->page_table_lock); |
| 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)) { |
| pc = lookup_page_cgroup(page); |
| if (!mem_cgroup_move_account(page, HPAGE_PMD_NR, |
| pc, mc.from, mc.to)) { |
| mc.precharge -= HPAGE_PMD_NR; |
| mc.moved_charge += HPAGE_PMD_NR; |
| } |
| putback_lru_page(page); |
| } |
| put_page(page); |
| } |
| spin_unlock(&vma->vm_mm->page_table_lock); |
| 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; |
| pc = lookup_page_cgroup(page); |
| if (!mem_cgroup_move_account(page, 1, pc, |
| 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 vm_area_struct *vma; |
| |
| lru_add_drain_all(); |
| retry: |
| if (unlikely(!down_read_trylock(&mm->mmap_sem))) { |
| /* |
| * Someone who are holding the mmap_sem might be waiting in |
| * waitq. So we cancel all extra charges, wake up all waiters, |
| * and retry. Because we cancel precharges, we might not be able |
| * to move enough charges, but moving charge is a best-effort |
| * feature anyway, so it wouldn't be a big problem. |
| */ |
| __mem_cgroup_clear_mc(); |
| cond_resched(); |
| goto retry; |
| } |
| for (vma = mm->mmap; vma; vma = vma->vm_next) { |
| int ret; |
| struct mm_walk mem_cgroup_move_charge_walk = { |
| .pmd_entry = mem_cgroup_move_charge_pte_range, |
| .mm = mm, |
| .private = vma, |
| }; |
| if (is_vm_hugetlb_page(vma)) |
| continue; |
| ret = walk_page_range(vma->vm_start, vma->vm_end, |
| &mem_cgroup_move_charge_walk); |
| if (ret) |
| /* |
| * means we have consumed all precharges and failed in |
| * doing additional charge. Just abandon here. |
| */ |
| break; |
| } |
| up_read(&mm->mmap_sem); |
| } |
| |
| static void mem_cgroup_move_task(struct cgroup_subsys_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 sane_behavior flag on each mount attempt. |
| */ |
| static void mem_cgroup_bind(struct cgroup_subsys_state *root_css) |
| { |
| /* |
| * use_hierarchy is forced with sane_behavior. cgroup core |
| * guarantees that @root doesn't have any children, so turning it |
| * on for the root memcg is enough. |
| */ |
| if (cgroup_sane_behavior(root_css->cgroup)) |
| mem_cgroup_from_css(root_css)->use_hierarchy = true; |
| } |
| |
| struct cgroup_subsys mem_cgroup_subsys = { |
| .name = "memory", |
| .subsys_id = mem_cgroup_subsys_id, |
| .css_alloc = mem_cgroup_css_alloc, |
| .css_online = mem_cgroup_css_online, |
| .css_offline = mem_cgroup_css_offline, |
| .css_free = mem_cgroup_css_free, |
| .can_attach = mem_cgroup_can_attach, |
| .cancel_attach = mem_cgroup_cancel_attach, |
| .attach = mem_cgroup_move_task, |
| .bind = mem_cgroup_bind, |
| .base_cftypes = mem_cgroup_files, |
| .early_init = 0, |
| .use_id = 1, |
| }; |
| |
| #ifdef CONFIG_MEMCG_SWAP |
| 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 void __init memsw_file_init(void) |
| { |
| WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys, memsw_cgroup_files)); |
| } |
| |
| static void __init enable_swap_cgroup(void) |
| { |
| if (!mem_cgroup_disabled() && really_do_swap_account) { |
| do_swap_account = 1; |
| memsw_file_init(); |
| } |
| } |
| |
| #else |
| static void __init enable_swap_cgroup(void) |
| { |
| } |
| #endif |
| |
| /* |
| * 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) |
| { |
| hotcpu_notifier(memcg_cpu_hotplug_callback, 0); |
| enable_swap_cgroup(); |
| mem_cgroup_soft_limit_tree_init(); |
| memcg_stock_init(); |
| return 0; |
| } |
| subsys_initcall(mem_cgroup_init); |