| /* 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 |
| * |
| * 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/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/mm_inline.h> |
| #include <linux/page_cgroup.h> |
| #include <linux/cpu.h> |
| #include <linux/oom.h> |
| #include "internal.h" |
| |
| #include <asm/uaccess.h> |
| |
| #include <trace/events/vmscan.h> |
| |
| struct cgroup_subsys mem_cgroup_subsys __read_mostly; |
| #define MEM_CGROUP_RECLAIM_RETRIES 5 |
| struct mem_cgroup *root_mem_cgroup __read_mostly; |
| |
| #ifdef CONFIG_CGROUP_MEM_RES_CTLR_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_CGROUP_MEM_RES_CTLR_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 |
| |
| /* |
| * Per memcg event counter is incremented at every pagein/pageout. This counter |
| * is used for trigger some periodic events. This is straightforward and better |
| * than using jiffies etc. to handle periodic memcg event. |
| * |
| * These values will be used as !((event) & ((1 <<(thresh)) - 1)) |
| */ |
| #define THRESHOLDS_EVENTS_THRESH (7) /* once in 128 */ |
| #define SOFTLIMIT_EVENTS_THRESH (10) /* once in 1024 */ |
| |
| /* |
| * Statistics for memory cgroup. |
| */ |
| enum mem_cgroup_stat_index { |
| /* |
| * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. |
| */ |
| MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ |
| MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */ |
| MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */ |
| MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */ |
| MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */ |
| MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */ |
| MEM_CGROUP_STAT_DATA, /* end of data requires synchronization */ |
| /* incremented at every pagein/pageout */ |
| MEM_CGROUP_EVENTS = MEM_CGROUP_STAT_DATA, |
| MEM_CGROUP_ON_MOVE, /* someone is moving account between groups */ |
| |
| MEM_CGROUP_STAT_NSTATS, |
| }; |
| |
| struct mem_cgroup_stat_cpu { |
| s64 count[MEM_CGROUP_STAT_NSTATS]; |
| }; |
| |
| /* |
| * per-zone information in memory controller. |
| */ |
| struct mem_cgroup_per_zone { |
| /* |
| * spin_lock to protect the per cgroup LRU |
| */ |
| struct list_head lists[NR_LRU_LISTS]; |
| unsigned long count[NR_LRU_LISTS]; |
| |
| struct zone_reclaim_stat reclaim_stat; |
| 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 *mem; /* Back pointer, we cannot */ |
| /* use container_of */ |
| }; |
| /* Macro for accessing counter */ |
| #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)]) |
| |
| struct mem_cgroup_per_node { |
| struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; |
| }; |
| |
| struct mem_cgroup_lru_info { |
| struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES]; |
| }; |
| |
| /* |
| * 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 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 *mem); |
| static void mem_cgroup_oom_notify(struct mem_cgroup *mem); |
| |
| /* |
| * 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; |
| /* |
| * the counter to account for mem+swap usage. |
| */ |
| struct res_counter memsw; |
| /* |
| * Per cgroup active and inactive list, similar to the |
| * per zone LRU lists. |
| */ |
| struct mem_cgroup_lru_info info; |
| |
| /* |
| protect against reclaim related member. |
| */ |
| spinlock_t reclaim_param_lock; |
| |
| /* |
| * While reclaiming in a hierarchy, we cache the last child we |
| * reclaimed from. |
| */ |
| int last_scanned_child; |
| /* |
| * Should the accounting and control be hierarchical, per subtree? |
| */ |
| bool use_hierarchy; |
| atomic_t oom_lock; |
| atomic_t refcnt; |
| |
| unsigned 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; |
| /* |
| * percpu counter. |
| */ |
| struct mem_cgroup_stat_cpu *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; |
| }; |
| |
| /* Stuffs for move charges at task migration. */ |
| /* |
| * Types of charges to be moved. "move_charge_at_immitgrate" is 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 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.to->move_charge_at_immigrate); |
| } |
| |
| static bool move_file(void) |
| { |
| return test_bit(MOVE_CHARGE_TYPE_FILE, |
| &mc.to->move_charge_at_immigrate); |
| } |
| |
| /* |
| * 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_MAPPED, |
| MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */ |
| MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */ |
| 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 */ |
| #define _MEM (0) |
| #define _MEMSWAP (1) |
| #define _OOM_TYPE (2) |
| #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) |
| #define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2 |
| #define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT) |
| |
| static void mem_cgroup_get(struct mem_cgroup *mem); |
| static void mem_cgroup_put(struct mem_cgroup *mem); |
| static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem); |
| static void drain_all_stock_async(void); |
| |
| static struct mem_cgroup_per_zone * |
| mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid) |
| { |
| return &mem->info.nodeinfo[nid]->zoneinfo[zid]; |
| } |
| |
| struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *mem) |
| { |
| return &mem->css; |
| } |
| |
| static struct mem_cgroup_per_zone * |
| page_cgroup_zoneinfo(struct page_cgroup *pc) |
| { |
| struct mem_cgroup *mem = pc->mem_cgroup; |
| int nid = page_cgroup_nid(pc); |
| int zid = page_cgroup_zid(pc); |
| |
| return mem_cgroup_zoneinfo(mem, 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 *mem, |
| 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 *mem, |
| 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 *mem, |
| struct mem_cgroup_per_zone *mz, |
| struct mem_cgroup_tree_per_zone *mctz) |
| { |
| spin_lock(&mctz->lock); |
| __mem_cgroup_remove_exceeded(mem, mz, mctz); |
| spin_unlock(&mctz->lock); |
| } |
| |
| |
| static void mem_cgroup_update_tree(struct mem_cgroup *mem, 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 (; mem; mem = parent_mem_cgroup(mem)) { |
| mz = mem_cgroup_zoneinfo(mem, nid, zid); |
| excess = res_counter_soft_limit_excess(&mem->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(mem, mz, mctz); |
| /* |
| * Insert again. mz->usage_in_excess will be updated. |
| * If excess is 0, no tree ops. |
| */ |
| __mem_cgroup_insert_exceeded(mem, mz, mctz, excess); |
| spin_unlock(&mctz->lock); |
| } |
| } |
| } |
| |
| static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem) |
| { |
| int node, zone; |
| struct mem_cgroup_per_zone *mz; |
| struct mem_cgroup_tree_per_zone *mctz; |
| |
| for_each_node_state(node, N_POSSIBLE) { |
| for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
| mz = mem_cgroup_zoneinfo(mem, node, zone); |
| mctz = soft_limit_tree_node_zone(node, zone); |
| mem_cgroup_remove_exceeded(mem, 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->mem, mz, mctz); |
| if (!res_counter_soft_limit_excess(&mz->mem->res) || |
| !css_tryget(&mz->mem->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 s64 mem_cgroup_read_stat(struct mem_cgroup *mem, |
| enum mem_cgroup_stat_index idx) |
| { |
| int cpu; |
| s64 val = 0; |
| |
| get_online_cpus(); |
| for_each_online_cpu(cpu) |
| val += per_cpu(mem->stat->count[idx], cpu); |
| #ifdef CONFIG_HOTPLUG_CPU |
| spin_lock(&mem->pcp_counter_lock); |
| val += mem->nocpu_base.count[idx]; |
| spin_unlock(&mem->pcp_counter_lock); |
| #endif |
| put_online_cpus(); |
| return val; |
| } |
| |
| static s64 mem_cgroup_local_usage(struct mem_cgroup *mem) |
| { |
| s64 ret; |
| |
| ret = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS); |
| ret += mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE); |
| return ret; |
| } |
| |
| static void mem_cgroup_swap_statistics(struct mem_cgroup *mem, |
| bool charge) |
| { |
| int val = (charge) ? 1 : -1; |
| this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_SWAPOUT], val); |
| } |
| |
| static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, |
| bool file, int nr_pages) |
| { |
| preempt_disable(); |
| |
| if (file) |
| __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_CACHE], nr_pages); |
| else |
| __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_RSS], nr_pages); |
| |
| /* pagein of a big page is an event. So, ignore page size */ |
| if (nr_pages > 0) |
| __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGIN_COUNT]); |
| else { |
| __this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGOUT_COUNT]); |
| nr_pages = -nr_pages; /* for event */ |
| } |
| |
| __this_cpu_add(mem->stat->count[MEM_CGROUP_EVENTS], nr_pages); |
| |
| preempt_enable(); |
| } |
| |
| static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem, |
| enum lru_list idx) |
| { |
| int nid, zid; |
| struct mem_cgroup_per_zone *mz; |
| u64 total = 0; |
| |
| for_each_online_node(nid) |
| for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
| mz = mem_cgroup_zoneinfo(mem, nid, zid); |
| total += MEM_CGROUP_ZSTAT(mz, idx); |
| } |
| return total; |
| } |
| |
| static bool __memcg_event_check(struct mem_cgroup *mem, int event_mask_shift) |
| { |
| s64 val; |
| |
| val = this_cpu_read(mem->stat->count[MEM_CGROUP_EVENTS]); |
| |
| return !(val & ((1 << event_mask_shift) - 1)); |
| } |
| |
| /* |
| * Check events in order. |
| * |
| */ |
| static void memcg_check_events(struct mem_cgroup *mem, struct page *page) |
| { |
| /* threshold event is triggered in finer grain than soft limit */ |
| if (unlikely(__memcg_event_check(mem, THRESHOLDS_EVENTS_THRESH))) { |
| mem_cgroup_threshold(mem); |
| if (unlikely(__memcg_event_check(mem, SOFTLIMIT_EVENTS_THRESH))) |
| mem_cgroup_update_tree(mem, page); |
| } |
| } |
| |
| static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) |
| { |
| return container_of(cgroup_subsys_state(cont, |
| mem_cgroup_subsys_id), struct mem_cgroup, |
| css); |
| } |
| |
| 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 container_of(task_subsys_state(p, mem_cgroup_subsys_id), |
| struct mem_cgroup, css); |
| } |
| |
| static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) |
| { |
| struct mem_cgroup *mem = 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 { |
| mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
| if (unlikely(!mem)) |
| break; |
| } while (!css_tryget(&mem->css)); |
| rcu_read_unlock(); |
| return mem; |
| } |
| |
| /* The caller has to guarantee "mem" exists before calling this */ |
| static struct mem_cgroup *mem_cgroup_start_loop(struct mem_cgroup *mem) |
| { |
| struct cgroup_subsys_state *css; |
| int found; |
| |
| if (!mem) /* ROOT cgroup has the smallest ID */ |
| return root_mem_cgroup; /*css_put/get against root is ignored*/ |
| if (!mem->use_hierarchy) { |
| if (css_tryget(&mem->css)) |
| return mem; |
| return NULL; |
| } |
| rcu_read_lock(); |
| /* |
| * searching a memory cgroup which has the smallest ID under given |
| * ROOT cgroup. (ID >= 1) |
| */ |
| css = css_get_next(&mem_cgroup_subsys, 1, &mem->css, &found); |
| if (css && css_tryget(css)) |
| mem = container_of(css, struct mem_cgroup, css); |
| else |
| mem = NULL; |
| rcu_read_unlock(); |
| return mem; |
| } |
| |
| static struct mem_cgroup *mem_cgroup_get_next(struct mem_cgroup *iter, |
| struct mem_cgroup *root, |
| bool cond) |
| { |
| int nextid = css_id(&iter->css) + 1; |
| int found; |
| int hierarchy_used; |
| struct cgroup_subsys_state *css; |
| |
| hierarchy_used = iter->use_hierarchy; |
| |
| css_put(&iter->css); |
| /* If no ROOT, walk all, ignore hierarchy */ |
| if (!cond || (root && !hierarchy_used)) |
| return NULL; |
| |
| if (!root) |
| root = root_mem_cgroup; |
| |
| do { |
| iter = NULL; |
| rcu_read_lock(); |
| |
| css = css_get_next(&mem_cgroup_subsys, nextid, |
| &root->css, &found); |
| if (css && css_tryget(css)) |
| iter = container_of(css, struct mem_cgroup, css); |
| rcu_read_unlock(); |
| /* If css is NULL, no more cgroups will be found */ |
| nextid = found + 1; |
| } while (css && !iter); |
| |
| return iter; |
| } |
| /* |
| * for_eacn_mem_cgroup_tree() for visiting all cgroup under tree. Please |
| * be careful that "break" loop is not allowed. We have reference count. |
| * Instead of that modify "cond" to be false and "continue" to exit the loop. |
| */ |
| #define for_each_mem_cgroup_tree_cond(iter, root, cond) \ |
| for (iter = mem_cgroup_start_loop(root);\ |
| iter != NULL;\ |
| iter = mem_cgroup_get_next(iter, root, cond)) |
| |
| #define for_each_mem_cgroup_tree(iter, root) \ |
| for_each_mem_cgroup_tree_cond(iter, root, true) |
| |
| #define for_each_mem_cgroup_all(iter) \ |
| for_each_mem_cgroup_tree_cond(iter, NULL, true) |
| |
| |
| static inline bool mem_cgroup_is_root(struct mem_cgroup *mem) |
| { |
| return (mem == root_mem_cgroup); |
| } |
| |
| /* |
| * 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. |
| */ |
| |
| void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru) |
| { |
| struct page_cgroup *pc; |
| struct mem_cgroup_per_zone *mz; |
| |
| if (mem_cgroup_disabled()) |
| return; |
| pc = lookup_page_cgroup(page); |
| /* can happen while we handle swapcache. */ |
| if (!TestClearPageCgroupAcctLRU(pc)) |
| return; |
| VM_BUG_ON(!pc->mem_cgroup); |
| /* |
| * We don't check PCG_USED bit. It's cleared when the "page" is finally |
| * removed from global LRU. |
| */ |
| mz = page_cgroup_zoneinfo(pc); |
| /* huge page split is done under lru_lock. so, we have no races. */ |
| MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page); |
| if (mem_cgroup_is_root(pc->mem_cgroup)) |
| return; |
| VM_BUG_ON(list_empty(&pc->lru)); |
| list_del_init(&pc->lru); |
| } |
| |
| void mem_cgroup_del_lru(struct page *page) |
| { |
| mem_cgroup_del_lru_list(page, page_lru(page)); |
| } |
| |
| /* |
| * Writeback is about to end against a page which has been marked for immediate |
| * reclaim. If it still appears to be reclaimable, move it to the tail of the |
| * inactive list. |
| */ |
| void mem_cgroup_rotate_reclaimable_page(struct page *page) |
| { |
| struct mem_cgroup_per_zone *mz; |
| struct page_cgroup *pc; |
| enum lru_list lru = page_lru(page); |
| |
| if (mem_cgroup_disabled()) |
| return; |
| |
| pc = lookup_page_cgroup(page); |
| /* unused or root page is not rotated. */ |
| if (!PageCgroupUsed(pc)) |
| return; |
| /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */ |
| smp_rmb(); |
| if (mem_cgroup_is_root(pc->mem_cgroup)) |
| return; |
| mz = page_cgroup_zoneinfo(pc); |
| list_move_tail(&pc->lru, &mz->lists[lru]); |
| } |
| |
| void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru) |
| { |
| struct mem_cgroup_per_zone *mz; |
| struct page_cgroup *pc; |
| |
| if (mem_cgroup_disabled()) |
| return; |
| |
| pc = lookup_page_cgroup(page); |
| /* unused or root page is not rotated. */ |
| if (!PageCgroupUsed(pc)) |
| return; |
| /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */ |
| smp_rmb(); |
| if (mem_cgroup_is_root(pc->mem_cgroup)) |
| return; |
| mz = page_cgroup_zoneinfo(pc); |
| list_move(&pc->lru, &mz->lists[lru]); |
| } |
| |
| void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru) |
| { |
| struct page_cgroup *pc; |
| struct mem_cgroup_per_zone *mz; |
| |
| if (mem_cgroup_disabled()) |
| return; |
| pc = lookup_page_cgroup(page); |
| VM_BUG_ON(PageCgroupAcctLRU(pc)); |
| if (!PageCgroupUsed(pc)) |
| return; |
| /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */ |
| smp_rmb(); |
| mz = page_cgroup_zoneinfo(pc); |
| /* huge page split is done under lru_lock. so, we have no races. */ |
| MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page); |
| SetPageCgroupAcctLRU(pc); |
| if (mem_cgroup_is_root(pc->mem_cgroup)) |
| return; |
| list_add(&pc->lru, &mz->lists[lru]); |
| } |
| |
| /* |
| * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to |
| * lru because the page may.be reused after it's fully uncharged (because of |
| * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge |
| * it again. This function is only used to charge SwapCache. It's done under |
| * lock_page and expected that zone->lru_lock is never held. |
| */ |
| static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page) |
| { |
| unsigned long flags; |
| struct zone *zone = page_zone(page); |
| struct page_cgroup *pc = lookup_page_cgroup(page); |
| |
| spin_lock_irqsave(&zone->lru_lock, flags); |
| /* |
| * Forget old LRU when this page_cgroup is *not* used. This Used bit |
| * is guarded by lock_page() because the page is SwapCache. |
| */ |
| if (!PageCgroupUsed(pc)) |
| mem_cgroup_del_lru_list(page, page_lru(page)); |
| spin_unlock_irqrestore(&zone->lru_lock, flags); |
| } |
| |
| static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page) |
| { |
| unsigned long flags; |
| struct zone *zone = page_zone(page); |
| struct page_cgroup *pc = lookup_page_cgroup(page); |
| |
| spin_lock_irqsave(&zone->lru_lock, flags); |
| /* link when the page is linked to LRU but page_cgroup isn't */ |
| if (PageLRU(page) && !PageCgroupAcctLRU(pc)) |
| mem_cgroup_add_lru_list(page, page_lru(page)); |
| spin_unlock_irqrestore(&zone->lru_lock, flags); |
| } |
| |
| |
| void mem_cgroup_move_lists(struct page *page, |
| enum lru_list from, enum lru_list to) |
| { |
| if (mem_cgroup_disabled()) |
| return; |
| mem_cgroup_del_lru_list(page, from); |
| mem_cgroup_add_lru_list(page, to); |
| } |
| |
| int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) |
| { |
| int ret; |
| struct mem_cgroup *curr = NULL; |
| struct task_struct *p; |
| |
| p = find_lock_task_mm(task); |
| if (!p) |
| return 0; |
| curr = try_get_mem_cgroup_from_mm(p->mm); |
| task_unlock(p); |
| if (!curr) |
| return 0; |
| /* |
| * We should check use_hierarchy of "mem" 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 "mem" in *cgroup* |
| * hierarchy(even if use_hierarchy is disabled in "mem"). |
| */ |
| if (mem->use_hierarchy) |
| ret = css_is_ancestor(&curr->css, &mem->css); |
| else |
| ret = (curr == mem); |
| css_put(&curr->css); |
| return ret; |
| } |
| |
| static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages) |
| { |
| unsigned long active; |
| unsigned long inactive; |
| unsigned long gb; |
| unsigned long inactive_ratio; |
| |
| inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_ANON); |
| active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_ANON); |
| |
| gb = (inactive + active) >> (30 - PAGE_SHIFT); |
| if (gb) |
| inactive_ratio = int_sqrt(10 * gb); |
| else |
| inactive_ratio = 1; |
| |
| if (present_pages) { |
| present_pages[0] = inactive; |
| present_pages[1] = active; |
| } |
| |
| return inactive_ratio; |
| } |
| |
| int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg) |
| { |
| unsigned long active; |
| unsigned long inactive; |
| unsigned long present_pages[2]; |
| unsigned long inactive_ratio; |
| |
| inactive_ratio = calc_inactive_ratio(memcg, present_pages); |
| |
| inactive = present_pages[0]; |
| active = present_pages[1]; |
| |
| if (inactive * inactive_ratio < active) |
| return 1; |
| |
| return 0; |
| } |
| |
| int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg) |
| { |
| unsigned long active; |
| unsigned long inactive; |
| |
| inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_FILE); |
| active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_FILE); |
| |
| return (active > inactive); |
| } |
| |
| unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg, |
| struct zone *zone, |
| enum lru_list lru) |
| { |
| int nid = zone_to_nid(zone); |
| int zid = zone_idx(zone); |
| struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
| |
| return MEM_CGROUP_ZSTAT(mz, lru); |
| } |
| |
| struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg, |
| struct zone *zone) |
| { |
| int nid = zone_to_nid(zone); |
| int zid = zone_idx(zone); |
| struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
| |
| return &mz->reclaim_stat; |
| } |
| |
| struct zone_reclaim_stat * |
| mem_cgroup_get_reclaim_stat_from_page(struct page *page) |
| { |
| struct page_cgroup *pc; |
| struct mem_cgroup_per_zone *mz; |
| |
| if (mem_cgroup_disabled()) |
| return NULL; |
| |
| pc = lookup_page_cgroup(page); |
| if (!PageCgroupUsed(pc)) |
| return NULL; |
| /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */ |
| smp_rmb(); |
| mz = page_cgroup_zoneinfo(pc); |
| if (!mz) |
| return NULL; |
| |
| return &mz->reclaim_stat; |
| } |
| |
| unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, |
| struct list_head *dst, |
| unsigned long *scanned, int order, |
| int mode, struct zone *z, |
| struct mem_cgroup *mem_cont, |
| int active, int file) |
| { |
| unsigned long nr_taken = 0; |
| struct page *page; |
| unsigned long scan; |
| LIST_HEAD(pc_list); |
| struct list_head *src; |
| struct page_cgroup *pc, *tmp; |
| int nid = zone_to_nid(z); |
| int zid = zone_idx(z); |
| struct mem_cgroup_per_zone *mz; |
| int lru = LRU_FILE * file + active; |
| int ret; |
| |
| BUG_ON(!mem_cont); |
| mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); |
| src = &mz->lists[lru]; |
| |
| scan = 0; |
| list_for_each_entry_safe_reverse(pc, tmp, src, lru) { |
| if (scan >= nr_to_scan) |
| break; |
| |
| page = pc->page; |
| if (unlikely(!PageCgroupUsed(pc))) |
| continue; |
| if (unlikely(!PageLRU(page))) |
| continue; |
| |
| scan++; |
| ret = __isolate_lru_page(page, mode, file); |
| switch (ret) { |
| case 0: |
| list_move(&page->lru, dst); |
| mem_cgroup_del_lru(page); |
| nr_taken += hpage_nr_pages(page); |
| break; |
| case -EBUSY: |
| /* we don't affect global LRU but rotate in our LRU */ |
| mem_cgroup_rotate_lru_list(page, page_lru(page)); |
| break; |
| default: |
| break; |
| } |
| } |
| |
| *scanned = scan; |
| |
| trace_mm_vmscan_memcg_isolate(0, nr_to_scan, scan, nr_taken, |
| 0, 0, 0, mode); |
| |
| return nr_taken; |
| } |
| |
| #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 |
| * @mem: the memory cgroup |
| * |
| * Returns the maximum amount of memory @mem can be charged with, in |
| * bytes. |
| */ |
| static unsigned long long mem_cgroup_margin(struct mem_cgroup *mem) |
| { |
| unsigned long long margin; |
| |
| margin = res_counter_margin(&mem->res); |
| if (do_swap_account) |
| margin = min(margin, res_counter_margin(&mem->memsw)); |
| return margin; |
| } |
| |
| static unsigned int get_swappiness(struct mem_cgroup *memcg) |
| { |
| struct cgroup *cgrp = memcg->css.cgroup; |
| unsigned int swappiness; |
| |
| /* root ? */ |
| if (cgrp->parent == NULL) |
| return vm_swappiness; |
| |
| spin_lock(&memcg->reclaim_param_lock); |
| swappiness = memcg->swappiness; |
| spin_unlock(&memcg->reclaim_param_lock); |
| |
| return swappiness; |
| } |
| |
| static void mem_cgroup_start_move(struct mem_cgroup *mem) |
| { |
| int cpu; |
| |
| get_online_cpus(); |
| spin_lock(&mem->pcp_counter_lock); |
| for_each_online_cpu(cpu) |
| per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) += 1; |
| mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] += 1; |
| spin_unlock(&mem->pcp_counter_lock); |
| put_online_cpus(); |
| |
| synchronize_rcu(); |
| } |
| |
| static void mem_cgroup_end_move(struct mem_cgroup *mem) |
| { |
| int cpu; |
| |
| if (!mem) |
| return; |
| get_online_cpus(); |
| spin_lock(&mem->pcp_counter_lock); |
| for_each_online_cpu(cpu) |
| per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) -= 1; |
| mem->nocpu_base.count[MEM_CGROUP_ON_MOVE] -= 1; |
| spin_unlock(&mem->pcp_counter_lock); |
| put_online_cpus(); |
| } |
| /* |
| * 2 routines for checking "mem" is under move_account() or not. |
| * |
| * mem_cgroup_stealed() - checking a cgroup is mc.from or not. This is used |
| * for avoiding race 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_stealed(struct mem_cgroup *mem) |
| { |
| VM_BUG_ON(!rcu_read_lock_held()); |
| return this_cpu_read(mem->stat->count[MEM_CGROUP_ON_MOVE]) > 0; |
| } |
| |
| static bool mem_cgroup_under_move(struct mem_cgroup *mem) |
| { |
| 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; |
| if (from == mem || to == mem |
| || (mem->use_hierarchy && css_is_ancestor(&from->css, &mem->css)) |
| || (mem->use_hierarchy && css_is_ancestor(&to->css, &mem->css))) |
| ret = true; |
| unlock: |
| spin_unlock(&mc.lock); |
| return ret; |
| } |
| |
| static bool mem_cgroup_wait_acct_move(struct mem_cgroup *mem) |
| { |
| if (mc.moving_task && current != mc.moving_task) { |
| if (mem_cgroup_under_move(mem)) { |
| 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; |
| } |
| |
| /** |
| * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode. |
| * @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; |
| |
| if (!memcg || !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(); |
| |
| printk(KERN_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 |
| */ |
| printk(KERN_CONT " as a result of limit of %s\n", memcg_name); |
| done: |
| |
| printk(KERN_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)); |
| printk(KERN_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)); |
| } |
| |
| /* |
| * 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 *mem) |
| { |
| int num = 0; |
| struct mem_cgroup *iter; |
| |
| for_each_mem_cgroup_tree(iter, mem) |
| num++; |
| return num; |
| } |
| |
| /* |
| * Return the memory (and swap, if configured) limit for a memcg. |
| */ |
| u64 mem_cgroup_get_limit(struct mem_cgroup *memcg) |
| { |
| u64 limit; |
| u64 memsw; |
| |
| limit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
| 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. |
| */ |
| return min(limit, memsw); |
| } |
| |
| /* |
| * Visit the first child (need not be the first child as per the ordering |
| * of the cgroup list, since we track last_scanned_child) of @mem and use |
| * that to reclaim free pages from. |
| */ |
| static struct mem_cgroup * |
| mem_cgroup_select_victim(struct mem_cgroup *root_mem) |
| { |
| struct mem_cgroup *ret = NULL; |
| struct cgroup_subsys_state *css; |
| int nextid, found; |
| |
| if (!root_mem->use_hierarchy) { |
| css_get(&root_mem->css); |
| ret = root_mem; |
| } |
| |
| while (!ret) { |
| rcu_read_lock(); |
| nextid = root_mem->last_scanned_child + 1; |
| css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css, |
| &found); |
| if (css && css_tryget(css)) |
| ret = container_of(css, struct mem_cgroup, css); |
| |
| rcu_read_unlock(); |
| /* Updates scanning parameter */ |
| spin_lock(&root_mem->reclaim_param_lock); |
| if (!css) { |
| /* this means start scan from ID:1 */ |
| root_mem->last_scanned_child = 0; |
| } else |
| root_mem->last_scanned_child = found; |
| spin_unlock(&root_mem->reclaim_param_lock); |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Scan the hierarchy if needed to reclaim memory. We remember the last child |
| * we reclaimed from, so that we don't end up penalizing one child extensively |
| * based on its position in the children list. |
| * |
| * root_mem is the original ancestor that we've been reclaim from. |
| * |
| * We give up and return to the caller when we visit root_mem twice. |
| * (other groups can be removed while we're walking....) |
| * |
| * If shrink==true, for avoiding to free too much, this returns immedieately. |
| */ |
| static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, |
| struct zone *zone, |
| gfp_t gfp_mask, |
| unsigned long reclaim_options) |
| { |
| struct mem_cgroup *victim; |
| int ret, total = 0; |
| int loop = 0; |
| bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP; |
| bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK; |
| bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT; |
| unsigned long excess; |
| |
| excess = res_counter_soft_limit_excess(&root_mem->res) >> PAGE_SHIFT; |
| |
| /* If memsw_is_minimum==1, swap-out is of-no-use. */ |
| if (root_mem->memsw_is_minimum) |
| noswap = true; |
| |
| while (1) { |
| victim = mem_cgroup_select_victim(root_mem); |
| if (victim == root_mem) { |
| loop++; |
| if (loop >= 1) |
| drain_all_stock_async(); |
| if (loop >= 2) { |
| /* |
| * If we have not been able to reclaim |
| * anything, it might because there are |
| * no reclaimable pages under this hierarchy |
| */ |
| if (!check_soft || !total) { |
| css_put(&victim->css); |
| break; |
| } |
| /* |
| * We want to do more targetted 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)) { |
| css_put(&victim->css); |
| break; |
| } |
| } |
| } |
| if (!mem_cgroup_local_usage(victim)) { |
| /* this cgroup's local usage == 0 */ |
| css_put(&victim->css); |
| continue; |
| } |
| /* we use swappiness of local cgroup */ |
| if (check_soft) |
| ret = mem_cgroup_shrink_node_zone(victim, gfp_mask, |
| noswap, get_swappiness(victim), zone); |
| else |
| ret = try_to_free_mem_cgroup_pages(victim, gfp_mask, |
| noswap, get_swappiness(victim)); |
| css_put(&victim->css); |
| /* |
| * At shrinking usage, we can't check we should stop here or |
| * reclaim more. It's depends on callers. last_scanned_child |
| * will work enough for keeping fairness under tree. |
| */ |
| if (shrink) |
| return ret; |
| total += ret; |
| if (check_soft) { |
| if (!res_counter_soft_limit_excess(&root_mem->res)) |
| return total; |
| } else if (mem_cgroup_margin(root_mem)) |
| return 1 + total; |
| } |
| return total; |
| } |
| |
| /* |
| * Check OOM-Killer is already running under our hierarchy. |
| * If someone is running, return false. |
| */ |
| static bool mem_cgroup_oom_lock(struct mem_cgroup *mem) |
| { |
| int x, lock_count = 0; |
| struct mem_cgroup *iter; |
| |
| for_each_mem_cgroup_tree(iter, mem) { |
| x = atomic_inc_return(&iter->oom_lock); |
| lock_count = max(x, lock_count); |
| } |
| |
| if (lock_count == 1) |
| return true; |
| return false; |
| } |
| |
| static int mem_cgroup_oom_unlock(struct mem_cgroup *mem) |
| { |
| 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, mem) |
| atomic_add_unless(&iter->oom_lock, -1, 0); |
| return 0; |
| } |
| |
| |
| static DEFINE_MUTEX(memcg_oom_mutex); |
| static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); |
| |
| struct oom_wait_info { |
| struct mem_cgroup *mem; |
| wait_queue_t wait; |
| }; |
| |
| static int memcg_oom_wake_function(wait_queue_t *wait, |
| unsigned mode, int sync, void *arg) |
| { |
| struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg; |
| struct oom_wait_info *oom_wait_info; |
| |
| oom_wait_info = container_of(wait, struct oom_wait_info, wait); |
| |
| if (oom_wait_info->mem == wake_mem) |
| goto wakeup; |
| /* if no hierarchy, no match */ |
| if (!oom_wait_info->mem->use_hierarchy || !wake_mem->use_hierarchy) |
| return 0; |
| /* |
| * Both of oom_wait_info->mem and wake_mem are stable under us. |
| * Then we can use css_is_ancestor without taking care of RCU. |
| */ |
| if (!css_is_ancestor(&oom_wait_info->mem->css, &wake_mem->css) && |
| !css_is_ancestor(&wake_mem->css, &oom_wait_info->mem->css)) |
| return 0; |
| |
| wakeup: |
| return autoremove_wake_function(wait, mode, sync, arg); |
| } |
| |
| static void memcg_wakeup_oom(struct mem_cgroup *mem) |
| { |
| /* for filtering, pass "mem" as argument. */ |
| __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, mem); |
| } |
| |
| static void memcg_oom_recover(struct mem_cgroup *mem) |
| { |
| if (mem && atomic_read(&mem->oom_lock)) |
| memcg_wakeup_oom(mem); |
| } |
| |
| /* |
| * try to call OOM killer. returns false if we should exit memory-reclaim loop. |
| */ |
| bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask) |
| { |
| struct oom_wait_info owait; |
| bool locked, need_to_kill; |
| |
| owait.mem = mem; |
| owait.wait.flags = 0; |
| owait.wait.func = memcg_oom_wake_function; |
| owait.wait.private = current; |
| INIT_LIST_HEAD(&owait.wait.task_list); |
| need_to_kill = true; |
| /* At first, try to OOM lock hierarchy under mem.*/ |
| mutex_lock(&memcg_oom_mutex); |
| locked = mem_cgroup_oom_lock(mem); |
| /* |
| * Even if signal_pending(), we can't quit charge() loop without |
| * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL |
| * under OOM is always welcomed, use TASK_KILLABLE here. |
| */ |
| prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); |
| if (!locked || mem->oom_kill_disable) |
| need_to_kill = false; |
| if (locked) |
| mem_cgroup_oom_notify(mem); |
| mutex_unlock(&memcg_oom_mutex); |
| |
| if (need_to_kill) { |
| finish_wait(&memcg_oom_waitq, &owait.wait); |
| mem_cgroup_out_of_memory(mem, mask); |
| } else { |
| schedule(); |
| finish_wait(&memcg_oom_waitq, &owait.wait); |
| } |
| mutex_lock(&memcg_oom_mutex); |
| mem_cgroup_oom_unlock(mem); |
| memcg_wakeup_oom(mem); |
| mutex_unlock(&memcg_oom_mutex); |
| |
| if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current)) |
| return false; |
| /* Give chance to dying process */ |
| schedule_timeout(1); |
| 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 MEM_CGROUP_ON_MOVE percpu value and detect there are |
| * possibility of race condition. If there is, we take a lock. |
| */ |
| |
| void mem_cgroup_update_page_stat(struct page *page, |
| enum mem_cgroup_page_stat_item idx, int val) |
| { |
| struct mem_cgroup *mem; |
| struct page_cgroup *pc = lookup_page_cgroup(page); |
| bool need_unlock = false; |
| unsigned long uninitialized_var(flags); |
| |
| if (unlikely(!pc)) |
| return; |
| |
| rcu_read_lock(); |
| mem = pc->mem_cgroup; |
| if (unlikely(!mem || !PageCgroupUsed(pc))) |
| goto out; |
| /* pc->mem_cgroup is unstable ? */ |
| if (unlikely(mem_cgroup_stealed(mem)) || PageTransHuge(page)) { |
| /* take a lock against to access pc->mem_cgroup */ |
| move_lock_page_cgroup(pc, &flags); |
| need_unlock = true; |
| mem = pc->mem_cgroup; |
| if (!mem || !PageCgroupUsed(pc)) |
| goto out; |
| } |
| |
| switch (idx) { |
| case MEMCG_NR_FILE_MAPPED: |
| if (val > 0) |
| SetPageCgroupFileMapped(pc); |
| else if (!page_mapped(page)) |
| ClearPageCgroupFileMapped(pc); |
| idx = MEM_CGROUP_STAT_FILE_MAPPED; |
| break; |
| default: |
| BUG(); |
| } |
| |
| this_cpu_add(mem->stat->count[idx], val); |
| |
| out: |
| if (unlikely(need_unlock)) |
| move_unlock_page_cgroup(pc, &flags); |
| rcu_read_unlock(); |
| return; |
| } |
| EXPORT_SYMBOL(mem_cgroup_update_page_stat); |
| |
| /* |
| * 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_SIZE (32 * PAGE_SIZE) |
| struct memcg_stock_pcp { |
| struct mem_cgroup *cached; /* this never be root cgroup */ |
| int charge; |
| struct work_struct work; |
| }; |
| static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); |
| static atomic_t memcg_drain_count; |
| |
| /* |
| * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed |
| * from local stock and true is returned. If the stock is 0 or charges from a |
| * cgroup which is not current target, returns false. This stock will be |
| * refilled. |
| */ |
| static bool consume_stock(struct mem_cgroup *mem) |
| { |
| struct memcg_stock_pcp *stock; |
| bool ret = true; |
| |
| stock = &get_cpu_var(memcg_stock); |
| if (mem == stock->cached && stock->charge) |
| stock->charge -= PAGE_SIZE; |
| 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->charge) { |
| res_counter_uncharge(&old->res, stock->charge); |
| if (do_swap_account) |
| res_counter_uncharge(&old->memsw, stock->charge); |
| } |
| stock->cached = NULL; |
| stock->charge = 0; |
| } |
| |
| /* |
| * 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); |
| } |
| |
| /* |
| * 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 *mem, int val) |
| { |
| struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); |
| |
| if (stock->cached != mem) { /* reset if necessary */ |
| drain_stock(stock); |
| stock->cached = mem; |
| } |
| stock->charge += val; |
| put_cpu_var(memcg_stock); |
| } |
| |
| /* |
| * 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(void) |
| { |
| int cpu; |
| /* This function is for scheduling "drain" in asynchronous way. |
| * The result of "drain" is not directly handled by callers. Then, |
| * if someone is calling drain, we don't have to call drain more. |
| * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if |
| * there is a race. We just do loose check here. |
| */ |
| if (atomic_read(&memcg_drain_count)) |
| return; |
| /* Notify other cpus that system-wide "drain" is running */ |
| atomic_inc(&memcg_drain_count); |
| get_online_cpus(); |
| for_each_online_cpu(cpu) { |
| struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); |
| schedule_work_on(cpu, &stock->work); |
| } |
| put_online_cpus(); |
| atomic_dec(&memcg_drain_count); |
| /* We don't wait for flush_work */ |
| } |
| |
| /* This is a synchronous drain interface. */ |
| static void drain_all_stock_sync(void) |
| { |
| /* called when force_empty is called */ |
| atomic_inc(&memcg_drain_count); |
| schedule_on_each_cpu(drain_local_stock); |
| atomic_dec(&memcg_drain_count); |
| } |
| |
| /* |
| * 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 *mem, int cpu) |
| { |
| int i; |
| |
| spin_lock(&mem->pcp_counter_lock); |
| for (i = 0; i < MEM_CGROUP_STAT_DATA; i++) { |
| s64 x = per_cpu(mem->stat->count[i], cpu); |
| |
| per_cpu(mem->stat->count[i], cpu) = 0; |
| mem->nocpu_base.count[i] += x; |
| } |
| /* need to clear ON_MOVE value, works as a kind of lock. */ |
| per_cpu(mem->stat->count[MEM_CGROUP_ON_MOVE], cpu) = 0; |
| spin_unlock(&mem->pcp_counter_lock); |
| } |
| |
| static void synchronize_mem_cgroup_on_move(struct mem_cgroup *mem, int cpu) |
| { |
| int idx = MEM_CGROUP_ON_MOVE; |
| |
| spin_lock(&mem->pcp_counter_lock); |
| per_cpu(mem->stat->count[idx], cpu) = mem->nocpu_base.count[idx]; |
| spin_unlock(&mem->pcp_counter_lock); |
| } |
| |
| static int __cpuinit 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)) { |
| for_each_mem_cgroup_all(iter) |
| synchronize_mem_cgroup_on_move(iter, cpu); |
| return NOTIFY_OK; |
| } |
| |
| if ((action != CPU_DEAD) || action != CPU_DEAD_FROZEN) |
| return NOTIFY_OK; |
| |
| for_each_mem_cgroup_all(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. */ |
| CHARGE_OOM_DIE, /* the current is killed because of OOM */ |
| }; |
| |
| static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask, |
| int csize, bool oom_check) |
| { |
| struct mem_cgroup *mem_over_limit; |
| struct res_counter *fail_res; |
| unsigned long flags = 0; |
| int ret; |
| |
| ret = res_counter_charge(&mem->res, csize, &fail_res); |
| |
| if (likely(!ret)) { |
| if (!do_swap_account) |
| return CHARGE_OK; |
| ret = res_counter_charge(&mem->memsw, csize, &fail_res); |
| if (likely(!ret)) |
| return CHARGE_OK; |
| |
| res_counter_uncharge(&mem->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); |
| /* |
| * csize can be either a huge page (HPAGE_SIZE), a batch of |
| * regular pages (CHARGE_SIZE), or a single regular page |
| * (PAGE_SIZE). |
| * |
| * Never reclaim on behalf of optional batching, retry with a |
| * single page instead. |
| */ |
| if (csize == CHARGE_SIZE) |
| return CHARGE_RETRY; |
| |
| if (!(gfp_mask & __GFP_WAIT)) |
| return CHARGE_WOULDBLOCK; |
| |
| ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL, |
| gfp_mask, flags); |
| if (mem_cgroup_margin(mem_over_limit) >= csize) |
| 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 (csize == PAGE_SIZE && 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 we don't need to call oom-killer at el, return immediately */ |
| if (!oom_check) |
| return CHARGE_NOMEM; |
| /* check OOM */ |
| if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask)) |
| return CHARGE_OOM_DIE; |
| |
| return CHARGE_RETRY; |
| } |
| |
| /* |
| * Unlike exported interface, "oom" parameter is added. if oom==true, |
| * oom-killer can be invoked. |
| */ |
| static int __mem_cgroup_try_charge(struct mm_struct *mm, |
| gfp_t gfp_mask, |
| struct mem_cgroup **memcg, bool oom, |
| int page_size) |
| { |
| int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; |
| struct mem_cgroup *mem = NULL; |
| int ret; |
| int csize = max(CHARGE_SIZE, (unsigned long) page_size); |
| |
| /* |
| * 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; |
| |
| /* |
| * We always charge the cgroup the mm_struct belongs to. |
| * The mm_struct's mem_cgroup changes on task migration if the |
| * thread group leader migrates. It's possible that mm is not |
| * set, if so charge the init_mm (happens for pagecache usage). |
| */ |
| if (!*memcg && !mm) |
| goto bypass; |
| again: |
| if (*memcg) { /* css should be a valid one */ |
| mem = *memcg; |
| VM_BUG_ON(css_is_removed(&mem->css)); |
| if (mem_cgroup_is_root(mem)) |
| goto done; |
| if (page_size == PAGE_SIZE && consume_stock(mem)) |
| goto done; |
| css_get(&mem->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, "mem" 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. |
| */ |
| mem = mem_cgroup_from_task(p); |
| if (!mem || mem_cgroup_is_root(mem)) { |
| rcu_read_unlock(); |
| goto done; |
| } |
| if (page_size == PAGE_SIZE && consume_stock(mem)) { |
| /* |
| * 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(&mem->css)) { |
| rcu_read_unlock(); |
| goto again; |
| } |
| rcu_read_unlock(); |
| } |
| |
| do { |
| bool oom_check; |
| |
| /* If killed, bypass charge */ |
| if (fatal_signal_pending(current)) { |
| css_put(&mem->css); |
| goto bypass; |
| } |
| |
| oom_check = false; |
| if (oom && !nr_oom_retries) { |
| oom_check = true; |
| nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; |
| } |
| |
| ret = __mem_cgroup_do_charge(mem, gfp_mask, csize, oom_check); |
| |
| switch (ret) { |
| case CHARGE_OK: |
| break; |
| case CHARGE_RETRY: /* not in OOM situation but retry */ |
| csize = page_size; |
| css_put(&mem->css); |
| mem = NULL; |
| goto again; |
| case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */ |
| css_put(&mem->css); |
| goto nomem; |
| case CHARGE_NOMEM: /* OOM routine works */ |
| if (!oom) { |
| css_put(&mem->css); |
| goto nomem; |
| } |
| /* If oom, we never return -ENOMEM */ |
| nr_oom_retries--; |
| break; |
| case CHARGE_OOM_DIE: /* Killed by OOM Killer */ |
| css_put(&mem->css); |
| goto bypass; |
| } |
| } while (ret != CHARGE_OK); |
| |
| if (csize > page_size) |
| refill_stock(mem, csize - page_size); |
| css_put(&mem->css); |
| done: |
| *memcg = mem; |
| return 0; |
| nomem: |
| *memcg = NULL; |
| return -ENOMEM; |
| bypass: |
| *memcg = NULL; |
| return 0; |
| } |
| |
| /* |
| * 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 *mem, |
| unsigned long count) |
| { |
| if (!mem_cgroup_is_root(mem)) { |
| res_counter_uncharge(&mem->res, PAGE_SIZE * count); |
| if (do_swap_account) |
| res_counter_uncharge(&mem->memsw, PAGE_SIZE * count); |
| } |
| } |
| |
| static void mem_cgroup_cancel_charge(struct mem_cgroup *mem, |
| int page_size) |
| { |
| __mem_cgroup_cancel_charge(mem, page_size >> PAGE_SHIFT); |
| } |
| |
| /* |
| * A helper function to get mem_cgroup from ID. must be called under |
| * rcu_read_lock(). The caller must check css_is_removed() or some if |
| * it's concern. (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 container_of(css, struct mem_cgroup, css); |
| } |
| |
| struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) |
| { |
| struct mem_cgroup *mem = 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)) { |
| mem = pc->mem_cgroup; |
| if (mem && !css_tryget(&mem->css)) |
| mem = NULL; |
| } else if (PageSwapCache(page)) { |
| ent.val = page_private(page); |
| id = lookup_swap_cgroup(ent); |
| rcu_read_lock(); |
| mem = mem_cgroup_lookup(id); |
| if (mem && !css_tryget(&mem->css)) |
| mem = NULL; |
| rcu_read_unlock(); |
| } |
| unlock_page_cgroup(pc); |
| return mem; |
| } |
| |
| static void __mem_cgroup_commit_charge(struct mem_cgroup *mem, |
| struct page_cgroup *pc, |
| enum charge_type ctype, |
| int page_size) |
| { |
| int nr_pages = page_size >> PAGE_SHIFT; |
| |
| lock_page_cgroup(pc); |
| if (unlikely(PageCgroupUsed(pc))) { |
| unlock_page_cgroup(pc); |
| mem_cgroup_cancel_charge(mem, page_size); |
| return; |
| } |
| /* |
| * we don't need page_cgroup_lock about tail pages, becase they are not |
| * accessed by any other context at this point. |
| */ |
| pc->mem_cgroup = mem; |
| /* |
| * 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(); |
| switch (ctype) { |
| case MEM_CGROUP_CHARGE_TYPE_CACHE: |
| case MEM_CGROUP_CHARGE_TYPE_SHMEM: |
| SetPageCgroupCache(pc); |
| SetPageCgroupUsed(pc); |
| break; |
| case MEM_CGROUP_CHARGE_TYPE_MAPPED: |
| ClearPageCgroupCache(pc); |
| SetPageCgroupUsed(pc); |
| break; |
| default: |
| break; |
| } |
| |
| mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), 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(mem, pc->page); |
| } |
| |
| #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
| |
| #define PCGF_NOCOPY_AT_SPLIT ((1 << PCG_LOCK) | (1 << PCG_MOVE_LOCK) |\ |
| (1 << PCG_ACCT_LRU) | (1 << PCG_MIGRATION)) |
| /* |
| * Because tail pages are not marked as "used", set it. We're under |
| * zone->lru_lock, 'splitting on pmd' and compund_lock. |
| */ |
| void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail) |
| { |
| struct page_cgroup *head_pc = lookup_page_cgroup(head); |
| struct page_cgroup *tail_pc = lookup_page_cgroup(tail); |
| unsigned long flags; |
| |
| if (mem_cgroup_disabled()) |
| return; |
| /* |
| * We have no races with charge/uncharge but will have races with |
| * page state accounting. |
| */ |
| move_lock_page_cgroup(head_pc, &flags); |
| |
| tail_pc->mem_cgroup = head_pc->mem_cgroup; |
| smp_wmb(); /* see __commit_charge() */ |
| if (PageCgroupAcctLRU(head_pc)) { |
| enum lru_list lru; |
| struct mem_cgroup_per_zone *mz; |
| |
| /* |
| * LRU flags cannot be copied because we need to add tail |
| *.page to LRU by generic call and our hook will be called. |
| * We hold lru_lock, then, reduce counter directly. |
| */ |
| lru = page_lru(head); |
| mz = page_cgroup_zoneinfo(head_pc); |
| MEM_CGROUP_ZSTAT(mz, lru) -= 1; |
| } |
| tail_pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT; |
| move_unlock_page_cgroup(head_pc, &flags); |
| } |
| #endif |
| |
| /** |
| * __mem_cgroup_move_account - move account of the page |
| * @pc: page_cgroup of the page. |
| * @from: mem_cgroup which the page is moved from. |
| * @to: mem_cgroup which the page is moved to. @from != @to. |
| * @uncharge: whether we should call uncharge and css_put against @from. |
| * |
| * The caller must confirm following. |
| * - page is not on LRU (isolate_page() is useful.) |
| * - the pc is locked, used, and ->mem_cgroup points to @from. |
| * |
| * This function doesn't do "charge" nor css_get to new cgroup. It should be |
| * done by a caller(__mem_cgroup_try_charge would be usefull). If @uncharge is |
| * true, this function does "uncharge" from old cgroup, but it doesn't if |
| * @uncharge is false, so a caller should do "uncharge". |
| */ |
| |
| static void __mem_cgroup_move_account(struct page_cgroup *pc, |
| struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge, |
| int charge_size) |
| { |
| int nr_pages = charge_size >> PAGE_SHIFT; |
| |
| VM_BUG_ON(from == to); |
| VM_BUG_ON(PageLRU(pc->page)); |
| VM_BUG_ON(!page_is_cgroup_locked(pc)); |
| VM_BUG_ON(!PageCgroupUsed(pc)); |
| VM_BUG_ON(pc->mem_cgroup != from); |
| |
| if (PageCgroupFileMapped(pc)) { |
| /* Update mapped_file data for mem_cgroup */ |
| preempt_disable(); |
| __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); |
| __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); |
| preempt_enable(); |
| } |
| mem_cgroup_charge_statistics(from, PageCgroupCache(pc), -nr_pages); |
| if (uncharge) |
| /* This is not "cancel", but cancel_charge does all we need. */ |
| mem_cgroup_cancel_charge(from, charge_size); |
| |
| /* caller should have done css_get */ |
| pc->mem_cgroup = to; |
| mem_cgroup_charge_statistics(to, PageCgroupCache(pc), nr_pages); |
| /* |
| * We charges against "to" which may not have any tasks. Then, "to" |
| * can be under rmdir(). But in current implementation, caller of |
| * this function is just force_empty() and move charge, so it's |
| * garanteed that "to" is never removed. So, we don't check rmdir |
| * status here. |
| */ |
| } |
| |
| /* |
| * check whether the @pc is valid for moving account and call |
| * __mem_cgroup_move_account() |
| */ |
| static int mem_cgroup_move_account(struct page_cgroup *pc, |
| struct mem_cgroup *from, struct mem_cgroup *to, |
| bool uncharge, int charge_size) |
| { |
| int ret = -EINVAL; |
| unsigned long flags; |
| /* |
| * 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. |
| */ |
| if ((charge_size > PAGE_SIZE) && !PageTransHuge(pc->page)) |
| return -EBUSY; |
| |
| lock_page_cgroup(pc); |
| if (PageCgroupUsed(pc) && pc->mem_cgroup == from) { |
| move_lock_page_cgroup(pc, &flags); |
| __mem_cgroup_move_account(pc, from, to, uncharge, charge_size); |
| move_unlock_page_cgroup(pc, &flags); |
| ret = 0; |
| } |
| unlock_page_cgroup(pc); |
| /* |
| * check events |
| */ |
| memcg_check_events(to, pc->page); |
| memcg_check_events(from, pc->page); |
| return ret; |
| } |
| |
| /* |
| * move charges to its parent. |
| */ |
| |
| static int mem_cgroup_move_parent(struct page_cgroup *pc, |
| struct mem_cgroup *child, |
| gfp_t gfp_mask) |
| { |
| struct page *page = pc->page; |
| struct cgroup *cg = child->css.cgroup; |
| struct cgroup *pcg = cg->parent; |
| struct mem_cgroup *parent; |
| int page_size = PAGE_SIZE; |
| unsigned long flags; |
| int ret; |
| |
| /* Is ROOT ? */ |
| if (!pcg) |
| return -EINVAL; |
| |
| ret = -EBUSY; |
| if (!get_page_unless_zero(page)) |
| goto out; |
| if (isolate_lru_page(page)) |
| goto put; |
| |
| if (PageTransHuge(page)) |
| page_size = HPAGE_SIZE; |
| |
| parent = mem_cgroup_from_cont(pcg); |
| ret = __mem_cgroup_try_charge(NULL, gfp_mask, |
| &parent, false, page_size); |
| if (ret || !parent) |
| goto put_back; |
| |
| if (page_size > PAGE_SIZE) |
| flags = compound_lock_irqsave(page); |
| |
| ret = mem_cgroup_move_account(pc, child, parent, true, page_size); |
| if (ret) |
| mem_cgroup_cancel_charge(parent, page_size); |
| |
| if (page_size > PAGE_SIZE) |
| compound_unlock_irqrestore(page, flags); |
| put_back: |
| 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 *mem = NULL; |
| int page_size = PAGE_SIZE; |
| struct page_cgroup *pc; |
| bool oom = true; |
| int ret; |
| |
| if (PageTransHuge(page)) { |
| page_size <<= 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; |
| } |
| |
| pc = lookup_page_cgroup(page); |
| BUG_ON(!pc); /* XXX: remove this and move pc lookup into commit */ |
| |
| ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, oom, page_size); |
| if (ret || !mem) |
| return ret; |
| |
| __mem_cgroup_commit_charge(mem, pc, ctype, page_size); |
| return 0; |
| } |
| |
| int mem_cgroup_newpage_charge(struct page *page, |
| struct mm_struct *mm, gfp_t gfp_mask) |
| { |
| if (mem_cgroup_disabled()) |
| return 0; |
| /* |
| * If already mapped, we don't have to account. |
| * If page cache, page->mapping has address_space. |
| * But page->mapping may have out-of-use anon_vma pointer, |
| * detecit it by PageAnon() check. newly-mapped-anon's page->mapping |
| * is NULL. |
| */ |
| if (page_mapped(page) || (page->mapping && !PageAnon(page))) |
| return 0; |
| if (unlikely(!mm)) |
| mm = &init_mm; |
| return mem_cgroup_charge_common(page, mm, gfp_mask, |
| MEM_CGROUP_CHARGE_TYPE_MAPPED); |
| } |
| |
| static void |
| __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, |
| enum charge_type ctype); |
| |
| int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, |
| gfp_t gfp_mask) |
| { |
| int ret; |
| |
| if (mem_cgroup_disabled()) |
| return 0; |
| if (PageCompound(page)) |
| return 0; |
| /* |
| * Corner case handling. This is called from add_to_page_cache() |
| * in usual. But some FS (shmem) precharges this page before calling it |
| * and call add_to_page_cache() with GFP_NOWAIT. |
| * |
| * For GFP_NOWAIT case, the page may be pre-charged before calling |
| * add_to_page_cache(). (See shmem.c) check it here and avoid to call |
| * charge twice. (It works but has to pay a bit larger cost.) |
| * And when the page is SwapCache, it should take swap information |
| * into account. This is under lock_page() now. |
| */ |
| if (!(gfp_mask & __GFP_WAIT)) { |
| struct page_cgroup *pc; |
| |
| pc = lookup_page_cgroup(page); |
| if (!pc) |
| return 0; |
| lock_page_cgroup(pc); |
| if (PageCgroupUsed(pc)) { |
| unlock_page_cgroup(pc); |
| return 0; |
| } |
| unlock_page_cgroup(pc); |
| } |
| |
| if (unlikely(!mm)) |
| mm = &init_mm; |
| |
| if (page_is_file_cache(page)) |
| return mem_cgroup_charge_common(page, mm, gfp_mask, |
| MEM_CGROUP_CHARGE_TYPE_CACHE); |
| |
| /* shmem */ |
| if (PageSwapCache(page)) { |
| struct mem_cgroup *mem; |
| |
| ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem); |
| if (!ret) |
| __mem_cgroup_commit_charge_swapin(page, mem, |
| MEM_CGROUP_CHARGE_TYPE_SHMEM); |
| } else |
| ret = mem_cgroup_charge_common(page, mm, gfp_mask, |
| MEM_CGROUP_CHARGE_TYPE_SHMEM); |
| |
| return ret; |
| } |
| |
| /* |
| * 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()" |
| */ |
| int mem_cgroup_try_charge_swapin(struct mm_struct *mm, |
| struct page *page, |
| gfp_t mask, struct mem_cgroup **ptr) |
| { |
| struct mem_cgroup *mem; |
| int ret; |
| |
| *ptr = NULL; |
| |
| if (mem_cgroup_disabled()) |
| return 0; |
| |
| if (!do_swap_account) |
| goto charge_cur_mm; |
| /* |
| * A racing thread's fault, or swapoff, may have already updated |
| * the pte, and even removed page from swap cache: in those cases |
| * do_swap_page()'s pte_same() test will fail; but there's also a |
| * KSM case which does need to charge the page. |
| */ |
| if (!PageSwapCache(page)) |
| goto charge_cur_mm; |
| mem = try_get_mem_cgroup_from_page(page); |
| if (!mem) |
| goto charge_cur_mm; |
| *ptr = mem; |
| ret = __mem_cgroup_try_charge(NULL, mask, ptr, true, PAGE_SIZE); |
| css_put(&mem->css); |
| return ret; |
| charge_cur_mm: |
| if (unlikely(!mm)) |
| mm = &init_mm; |
| return __mem_cgroup_try_charge(mm, mask, ptr, true, PAGE_SIZE); |
| } |
| |
| static void |
| __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, |
| enum charge_type ctype) |
| { |
| struct page_cgroup *pc; |
| |
| if (mem_cgroup_disabled()) |
| return; |
| if (!ptr) |
| return; |
| cgroup_exclude_rmdir(&ptr->css); |
| pc = lookup_page_cgroup(page); |
| mem_cgroup_lru_del_before_commit_swapcache(page); |
| __mem_cgroup_commit_charge(ptr, pc, ctype, PAGE_SIZE); |
| mem_cgroup_lru_add_after_commit_swapcache(page); |
| /* |
| * 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)}; |
| unsigned short id; |
| struct mem_cgroup *memcg; |
| |
| id = swap_cgroup_record(ent, 0); |
| rcu_read_lock(); |
| memcg = mem_cgroup_lookup(id); |
| if (memcg) { |
| /* |
| * This recorded memcg can be obsolete one. So, avoid |
| * calling css_tryget |
| */ |
| if (!mem_cgroup_is_root(memcg)) |
| res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
| mem_cgroup_swap_statistics(memcg, false); |
| mem_cgroup_put(memcg); |
| } |
| rcu_read_unlock(); |
| } |
| /* |
| * At swapin, we may charge account against cgroup which has no tasks. |
| * So, rmdir()->pre_destroy() can be called while we do this charge. |
| * In that case, we need to call pre_destroy() again. check it here. |
| */ |
| cgroup_release_and_wakeup_rmdir(&ptr->css); |
| } |
| |
| void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr) |
| { |
| __mem_cgroup_commit_charge_swapin(page, ptr, |
| MEM_CGROUP_CHARGE_TYPE_MAPPED); |
| } |
| |
| void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem) |
| { |
| if (mem_cgroup_disabled()) |
| return; |
| if (!mem) |
| return; |
| mem_cgroup_cancel_charge(mem, PAGE_SIZE); |
| } |
| |
| static void |
| __do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype, |
| int page_size) |
| { |
| 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 = mem; |
| /* |
| * do_batch > 0 when unmapping pages or inode invalidate/truncate. |
| * In those cases, all pages freed continously 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 (page_size != PAGE_SIZE) |
| 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 != mem) |
| goto direct_uncharge; |
| /* remember freed charge and uncharge it later */ |
| batch->bytes += PAGE_SIZE; |
| if (uncharge_memsw) |
| batch->memsw_bytes += PAGE_SIZE; |
| return; |
| direct_uncharge: |
| res_counter_uncharge(&mem->res, page_size); |
| if (uncharge_memsw) |
| res_counter_uncharge(&mem->memsw, page_size); |
| if (unlikely(batch->memcg != mem)) |
| memcg_oom_recover(mem); |
| return; |
| } |
| |
| /* |
| * uncharge if !page_mapped(page) |
| */ |
| static struct mem_cgroup * |
| __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) |
| { |
| int count; |
| struct page_cgroup *pc; |
| struct mem_cgroup *mem = NULL; |
| int page_size = PAGE_SIZE; |
| |
| if (mem_cgroup_disabled()) |
| return NULL; |
| |
| if (PageSwapCache(page)) |
| return NULL; |
| |
| if (PageTransHuge(page)) { |
| page_size <<= compound_order(page); |
| VM_BUG_ON(!PageTransHuge(page)); |
| } |
| |
| count = page_size >> PAGE_SHIFT; |
| /* |
| * Check if our page_cgroup is valid |
| */ |
| pc = lookup_page_cgroup(page); |
| if (unlikely(!pc || !PageCgroupUsed(pc))) |
| return NULL; |
| |
| lock_page_cgroup(pc); |
| |
| mem = pc->mem_cgroup; |
| |
| if (!PageCgroupUsed(pc)) |
| goto unlock_out; |
| |
| switch (ctype) { |
| case MEM_CGROUP_CHARGE_TYPE_MAPPED: |
| case MEM_CGROUP_CHARGE_TYPE_DROP: |
| /* See mem_cgroup_prepare_migration() */ |
| if (page_mapped(page) || 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(mem, PageCgroupCache(pc), -count); |
| |
| 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 mem->res.usage here and this memcg |
| * will never be freed. |
| */ |
| memcg_check_events(mem, page); |
| if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) { |
| mem_cgroup_swap_statistics(mem, true); |
| mem_cgroup_get(mem); |
| } |
| if (!mem_cgroup_is_root(mem)) |
| __do_uncharge(mem, ctype, page_size); |
| |
| return mem; |
| |
| unlock_out: |
| unlock_page_cgroup(pc); |
| return NULL; |
| } |
| |
| void mem_cgroup_uncharge_page(struct page *page) |
| { |
| /* early check. */ |
| if (page_mapped(page)) |
| return; |
| if (page->mapping && !PageAnon(page)) |
| return; |
| __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED); |
| } |
| |
| void mem_cgroup_uncharge_cache_page(struct page *page) |
| { |
| VM_BUG_ON(page_mapped(page)); |
| VM_BUG_ON(page->mapping); |
| __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE); |
| } |
| |
| /* |
| * 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.bytes = 0; |
| current->memcg_batch.memsw_bytes = 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->bytes) |
| res_counter_uncharge(&batch->memcg->res, batch->bytes); |
| if (batch->memsw_bytes) |
| res_counter_uncharge(&batch->memcg->memsw, batch->memsw_bytes); |
| 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); |
| |
| /* |
| * record memcg information, if swapout && memcg != NULL, |
| * mem_cgroup_get() was called in uncharge(). |
| */ |
| if (do_swap_account && swapout && memcg) |
| swap_cgroup_record(ent, css_id(&memcg->css)); |
| } |
| #endif |
| |
| #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
| /* |
| * called from swap_entry_free(). remove record in swap_cgroup and |
| * uncharge "memsw" account. |
| */ |
| void mem_cgroup_uncharge_swap(swp_entry_t ent) |
| { |
| 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); |
| mem_cgroup_put(memcg); |
| } |
| 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 |
| * @need_fixup: whether we should fixup res_counters and refcounts. |
| * |
| * 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, bool need_fixup) |
| { |
| 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 mem_cgroup_get(to) |
| * because if the process that has been moved to @to does |
| * swap-in, the refcount of @to might be decreased to 0. |
| */ |
| mem_cgroup_get(to); |
| if (need_fixup) { |
| if (!mem_cgroup_is_root(from)) |
| res_counter_uncharge(&from->memsw, PAGE_SIZE); |
| mem_cgroup_put(from); |
| /* |
| * we charged both to->res and to->memsw, so we should |
| * uncharge to->res. |
| */ |
| if (!mem_cgroup_is_root(to)) |
| res_counter_uncharge(&to->res, PAGE_SIZE); |
| } |
| 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, bool need_fixup) |
| { |
| return -EINVAL; |
| } |
| #endif |
| |
| /* |
| * Before starting migration, account PAGE_SIZE to mem_cgroup that the old |
| * page belongs to. |
| */ |
| int mem_cgroup_prepare_migration(struct page *page, |
| struct page *newpage, struct mem_cgroup **ptr, gfp_t gfp_mask) |
| { |
| struct page_cgroup *pc; |
| struct mem_cgroup *mem = NULL; |
| enum charge_type ctype; |
| int ret = 0; |
| |
| *ptr = NULL; |
| |
| VM_BUG_ON(PageTransHuge(page)); |
| if (mem_cgroup_disabled()) |
| return 0; |
| |
| pc = lookup_page_cgroup(page); |
| lock_page_cgroup(pc); |
| if (PageCgroupUsed(pc)) { |
| mem = pc->mem_cgroup; |
| css_get(&mem->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 (!mem) |
| return 0; |
| |
| *ptr = mem; |
| ret = __mem_cgroup_try_charge(NULL, gfp_mask, ptr, false, PAGE_SIZE); |
| css_put(&mem->css);/* drop extra refcnt */ |
| if (ret || *ptr == NULL) { |
| if (PageAnon(page)) { |
| lock_page_cgroup(pc); |
| ClearPageCgroupMigration(pc); |
| unlock_page_cgroup(pc); |
| /* |
| * The old page may be fully unmapped while we kept it. |
| */ |
| mem_cgroup_uncharge_page(page); |
| } |
| return -ENOMEM; |
| } |
| /* |
| * 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(). |
| */ |
| pc = lookup_page_cgroup(newpage); |
| if (PageAnon(page)) |
| ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED; |
| else if (page_is_file_cache(page)) |
| ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; |
| else |
| ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM; |
| __mem_cgroup_commit_charge(mem, pc, ctype, PAGE_SIZE); |
| return ret; |
| } |
| |
| /* remove redundant charge if migration failed*/ |
| void mem_cgroup_end_migration(struct mem_cgroup *mem, |
| struct page *oldpage, struct page *newpage, bool migration_ok) |
| { |
| struct page *used, *unused; |
| struct page_cgroup *pc; |
| |
| if (!mem) |
| return; |
| /* blocks rmdir() */ |
| cgroup_exclude_rmdir(&mem->css); |
| if (!migration_ok) { |
| used = oldpage; |
| unused = newpage; |
| } else { |
| used = newpage; |
| unused = oldpage; |
| } |
| /* |
| * 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); |
| |
| __mem_cgroup_uncharge_common(unused, MEM_CGROUP_CHARGE_TYPE_FORCE); |
| |
| /* |
| * 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 (PageAnon(used)) |
| mem_cgroup_uncharge_page(used); |
| /* |
| * At migration, we may charge account against cgroup which has no |
| * tasks. |
| * So, rmdir()->pre_destroy() can be called while we do this charge. |
| * In that case, we need to call pre_destroy() again. check it here. |
| */ |
| cgroup_release_and_wakeup_rmdir(&mem->css); |
| } |
| |
| /* |
| * A call to try to shrink memory usage on charge failure at shmem's swapin. |
| * Calling hierarchical_reclaim is not enough because we should update |
| * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM. |
| * Moreover considering hierarchy, we should reclaim from the mem_over_limit, |
| * not from the memcg which this page would be charged to. |
| * try_charge_swapin does all of these works properly. |
| */ |
| int mem_cgroup_shmem_charge_fallback(struct page *page, |
| struct mm_struct *mm, |
| gfp_t gfp_mask) |
| { |
| struct mem_cgroup *mem; |
| int ret; |
| |
| if (mem_cgroup_disabled()) |
| return 0; |
| |
| ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem); |
| if (!ret) |
| mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */ |
| |
| return ret; |
| } |
| |
| #ifdef CONFIG_DEBUG_VM |
| static struct page_cgroup *lookup_page_cgroup_used(struct page *page) |
| { |
| struct page_cgroup *pc; |
| |
| pc = lookup_page_cgroup(page); |
| 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) { |
| int ret = -1; |
| char *path; |
| |
| printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p", |
| pc, pc->flags, pc->mem_cgroup); |
| |
| path = kmalloc(PATH_MAX, GFP_KERNEL); |
| if (path) { |
| rcu_read_lock(); |
| ret = cgroup_path(pc->mem_cgroup->css.cgroup, |
| path, PATH_MAX); |
| rcu_read_unlock(); |
| } |
| |
| printk(KERN_CONT "(%s)\n", |
| (ret < 0) ? "cannot get the path" : path); |
| kfree(path); |
| } |
| } |
| #endif |
| |
| static DEFINE_MUTEX(set_limit_mutex); |
| |
| 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 mem->res.limit < mem->memsw.limit. |
| */ |
| mutex_lock(&set_limit_mutex); |
| memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
| if (memswlimit < val) { |
| ret = -EINVAL; |
| mutex_unlock(&set_limit_mutex); |
| 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_hierarchical_reclaim(memcg, NULL, 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 mem->res.limit < mem->memsw.limit. |
| */ |
| mutex_lock(&set_limit_mutex); |
| memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
| if (memlimit > val) { |
| ret = -EINVAL; |
| mutex_unlock(&set_limit_mutex); |
| break; |
| } |
| 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_hierarchical_reclaim(memcg, NULL, 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 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; |
| |
| 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; |
| |
| reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone, |
| gfp_mask, |
| MEM_CGROUP_RECLAIM_SOFT); |
| nr_reclaimed += reclaimed; |
| 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->mem->css); |
| next_mz = NULL; |
| } else /* next_mz == NULL or other memcg */ |
| break; |
| } while (1); |
| } |
| __mem_cgroup_remove_exceeded(mz->mem, mz, mctz); |
| excess = res_counter_soft_limit_excess(&mz->mem->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->mem, mz, mctz, excess); |
| spin_unlock(&mctz->lock); |
| css_put(&mz->mem->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->mem->css); |
| return nr_reclaimed; |
| } |
| |
| /* |
| * This routine traverse page_cgroup in given list and drop them all. |
| * *And* this routine doesn't reclaim page itself, just removes page_cgroup. |
| */ |
| static int mem_cgroup_force_empty_list(struct mem_cgroup *mem, |
| int node, int zid, enum lru_list lru) |
| { |
| struct zone *zone; |
| struct mem_cgroup_per_zone *mz; |
| struct page_cgroup *pc, *busy; |
| unsigned long flags, loop; |
| struct list_head *list; |
| int ret = 0; |
| |
| zone = &NODE_DATA(node)->node_zones[zid]; |
| mz = mem_cgroup_zoneinfo(mem, node, zid); |
| list = &mz->lists[lru]; |
| |
| loop = MEM_CGROUP_ZSTAT(mz, lru); |
| /* give some margin against EBUSY etc...*/ |
| loop += 256; |
| busy = NULL; |
| while (loop--) { |
| ret = 0; |
| spin_lock_irqsave(&zone->lru_lock, flags); |
| if (list_empty(list)) { |
| spin_unlock_irqrestore(&zone->lru_lock, flags); |
| break; |
| } |
| pc = list_entry(list->prev, struct page_cgroup, lru); |
| if (busy == pc) { |
| list_move(&pc->lru, list); |
| busy = NULL; |
| spin_unlock_irqrestore(&zone->lru_lock, flags); |
| continue; |
| } |
| spin_unlock_irqrestore(&zone->lru_lock, flags); |
| |
| ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL); |
| if (ret == -ENOMEM) |
| break; |
| |
| if (ret == -EBUSY || ret == -EINVAL) { |
| /* found lock contention or "pc" is obsolete. */ |
| busy = pc; |
| cond_resched(); |
| } else |
| busy = NULL; |
| } |
| |
| if (!ret && !list_empty(list)) |
| return -EBUSY; |
| return ret; |
| } |
| |
| /* |
| * make mem_cgroup's charge to be 0 if there is no task. |
| * This enables deleting this mem_cgroup. |
| */ |
| static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all) |
| { |
| int ret; |
| int node, zid, shrink; |
| int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; |
| struct cgroup *cgrp = mem->css.cgroup; |
| |
| css_get(&mem->css); |
| |
| shrink = 0; |
| /* should free all ? */ |
| if (free_all) |
| goto try_to_free; |
| move_account: |
| do { |
| ret = -EBUSY; |
| if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) |
| goto out; |
| ret = -EINTR; |
| if (signal_pending(current)) |
| goto out; |
| /* This is for making all *used* pages to be on LRU. */ |
| lru_add_drain_all(); |
| drain_all_stock_sync(); |
| ret = 0; |
| mem_cgroup_start_move(mem); |
| for_each_node_state(node, N_HIGH_MEMORY) { |
| for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) { |
| enum lru_list l; |
| for_each_lru(l) { |
| ret = mem_cgroup_force_empty_list(mem, |
| node, zid, l); |
| if (ret) |
| break; |
| } |
| } |
| if (ret) |
| break; |
| } |
| mem_cgroup_end_move(mem); |
| memcg_oom_recover(mem); |
| /* it seems parent cgroup doesn't have enough mem */ |
| if (ret == -ENOMEM) |
| goto try_to_free; |
| cond_resched(); |
| /* "ret" should also be checked to ensure all lists are empty. */ |
| } while (mem->res.usage > 0 || ret); |
| out: |
| css_put(&mem->css); |
| return ret; |
| |
| try_to_free: |
| /* returns EBUSY if there is a task or if we come here twice. */ |
| if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) { |
| ret = -EBUSY; |
| goto out; |
| } |
| /* we call try-to-free pages for make this cgroup empty */ |
| lru_add_drain_all(); |
| /* try to free all pages in this cgroup */ |
| shrink = 1; |
| while (nr_retries && mem->res.usage > 0) { |
| int progress; |
| |
| if (signal_pending(current)) { |
| ret = -EINTR; |
| goto out; |
| } |
| progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL, |
| false, get_swappiness(mem)); |
| if (!progress) { |
| nr_retries--; |
| /* maybe some writeback is necessary */ |
| congestion_wait(BLK_RW_ASYNC, HZ/10); |
| } |
| |
| } |
| lru_add_drain(); |
| /* try move_account...there may be some *locked* pages. */ |
| goto move_account; |
| } |
| |
| int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event) |
| { |
| return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true); |
| } |
| |
| |
| static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft) |
| { |
| return mem_cgroup_from_cont(cont)->use_hierarchy; |
| } |
| |
| static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, |
| u64 val) |
| { |
| int retval = 0; |
| struct mem_cgroup *mem = mem_cgroup_from_cont(cont); |
| struct cgroup *parent = cont->parent; |
| struct mem_cgroup *parent_mem = NULL; |
| |
| if (parent) |
| parent_mem = mem_cgroup_from_cont(parent); |
| |
| cgroup_lock(); |
| /* |
| * If parent's use_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_mem || !parent_mem->use_hierarchy) && |
| (val == 1 || val == 0)) { |
| if (list_empty(&cont->children)) |
| mem->use_hierarchy = val; |
| else |
| retval = -EBUSY; |
| } else |
| retval = -EINVAL; |
| cgroup_unlock(); |
| |
| return retval; |
| } |
| |
| |
| static u64 mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem, |
| enum mem_cgroup_stat_index idx) |
| { |
| struct mem_cgroup *iter; |
| s64 val = 0; |
| |
| /* each per cpu's value can be minus.Then, use s64 */ |
| for_each_mem_cgroup_tree(iter, mem) |
| val += mem_cgroup_read_stat(iter, idx); |
| |
| if (val < 0) /* race ? */ |
| val = 0; |
| return val; |
| } |
| |
| static inline u64 mem_cgroup_usage(struct mem_cgroup *mem, bool swap) |
| { |
| u64 val; |
| |
| if (!mem_cgroup_is_root(mem)) { |
| if (!swap) |
| return res_counter_read_u64(&mem->res, RES_USAGE); |
| else |
| return res_counter_read_u64(&mem->memsw, RES_USAGE); |
| } |
| |
| val = mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_CACHE); |
| val += mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_RSS); |
| |
| if (swap) |
| val += mem_cgroup_get_recursive_idx_stat(mem, |
| MEM_CGROUP_STAT_SWAPOUT); |
| |
| return val << PAGE_SHIFT; |
| } |
| |
| static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft) |
| { |
| struct mem_cgroup *mem = mem_cgroup_from_cont(cont); |
| u64 val; |
| int type, name; |
| |
| type = MEMFILE_TYPE(cft->private); |
| name = MEMFILE_ATTR(cft->private); |
| switch (type) { |
| case _MEM: |
| if (name == RES_USAGE) |
| val = mem_cgroup_usage(mem, false); |
| else |
| val = res_counter_read_u64(&mem->res, name); |
| break; |
| case _MEMSWAP: |
| if (name == RES_USAGE) |
| val = mem_cgroup_usage(mem, true); |
| else |
| val = res_counter_read_u64(&mem->memsw, name); |
| break; |
| default: |
| BUG(); |
| break; |
| } |
| return val; |
| } |
| /* |
| * The user of this function is... |
| * RES_LIMIT. |
| */ |
| static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, |
| const char *buffer) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
| int type, 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 |
| ret = mem_cgroup_resize_memsw_limit(memcg, val); |
| 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) |
| { |
| struct cgroup *cgroup; |
| unsigned long long min_limit, min_memsw_limit, tmp; |
| |
| min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
| min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
| cgroup = memcg->css.cgroup; |
| if (!memcg->use_hierarchy) |
| goto out; |
| |
| while (cgroup->parent) { |
| cgroup = cgroup->parent; |
| memcg = mem_cgroup_from_cont(cgroup); |
| if (!memcg->use_hierarchy) |
| break; |
| tmp = res_counter_read_u64(&memcg->res, RES_LIMIT); |
| min_limit = min(min_limit, tmp); |
| tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
| min_memsw_limit = min(min_memsw_limit, tmp); |
| } |
| out: |
| *mem_limit = min_limit; |
| *memsw_limit = min_memsw_limit; |
| return; |
| } |
| |
| static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) |
| { |
| struct mem_cgroup *mem; |
| int type, name; |
| |
| mem = mem_cgroup_from_cont(cont); |
| type = MEMFILE_TYPE(event); |
| name = MEMFILE_ATTR(event); |
| switch (name) { |
| case RES_MAX_USAGE: |
| if (type == _MEM) |
| res_counter_reset_max(&mem->res); |
| else |
| res_counter_reset_max(&mem->memsw); |
| break; |
| case RES_FAILCNT: |
| if (type == _MEM) |
| res_counter_reset_failcnt(&mem->res); |
| else |
| res_counter_reset_failcnt(&mem->memsw); |
| break; |
| } |
| |
| return 0; |
| } |
| |
| static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp, |
| struct cftype *cft) |
| { |
| return mem_cgroup_from_cont(cgrp)->move_charge_at_immigrate; |
| } |
| |
| #ifdef CONFIG_MMU |
| static int mem_cgroup_move_charge_write(struct cgroup *cgrp, |
| struct cftype *cft, u64 val) |
| { |
| struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); |
| |
| if (val >= (1 << NR_MOVE_TYPE)) |
| return -EINVAL; |
| /* |
| * We check this value several times in both in can_attach() and |
| * attach(), so we need cgroup lock to prevent this value from being |
| * inconsistent. |
| */ |
| cgroup_lock(); |
| mem->move_charge_at_immigrate = val; |
| cgroup_unlock(); |
| |
| return 0; |
| } |
| #else |
| static int mem_cgroup_move_charge_write(struct cgroup *cgrp, |
| struct cftype *cft, u64 val) |
| { |
| return -ENOSYS; |
| } |
| #endif |
| |
| |
| /* For read statistics */ |
| enum { |
| MCS_CACHE, |
| MCS_RSS, |
| MCS_FILE_MAPPED, |
| MCS_PGPGIN, |
| MCS_PGPGOUT, |
| MCS_SWAP, |
| MCS_INACTIVE_ANON, |
| MCS_ACTIVE_ANON, |
| MCS_INACTIVE_FILE, |
| MCS_ACTIVE_FILE, |
| MCS_UNEVICTABLE, |
| NR_MCS_STAT, |
| }; |
| |
| struct mcs_total_stat { |
| s64 stat[NR_MCS_STAT]; |
| }; |
| |
| struct { |
| char *local_name; |
| char *total_name; |
| } memcg_stat_strings[NR_MCS_STAT] = { |
| {"cache", "total_cache"}, |
| {"rss", "total_rss"}, |
| {"mapped_file", "total_mapped_file"}, |
| {"pgpgin", "total_pgpgin"}, |
| {"pgpgout", "total_pgpgout"}, |
| {"swap", "total_swap"}, |
| {"inactive_anon", "total_inactive_anon"}, |
| {"active_anon", "total_active_anon"}, |
| {"inactive_file", "total_inactive_file"}, |
| {"active_file", "total_active_file"}, |
| {"unevictable", "total_unevictable"} |
| }; |
| |
| |
| static void |
| mem_cgroup_get_local_stat(struct mem_cgroup *mem, struct mcs_total_stat *s) |
| { |
| s64 val; |
| |
| /* per cpu stat */ |
| val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE); |
| s->stat[MCS_CACHE] += val * PAGE_SIZE; |
| val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS); |
| s->stat[MCS_RSS] += val * PAGE_SIZE; |
| val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_FILE_MAPPED); |
| s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE; |
| val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGIN_COUNT); |
| s->stat[MCS_PGPGIN] += val; |
| val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGOUT_COUNT); |
| s->stat[MCS_PGPGOUT] += val; |
| if (do_swap_account) { |
| val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_SWAPOUT); |
| s->stat[MCS_SWAP] += val * PAGE_SIZE; |
| } |
| |
| /* per zone stat */ |
| val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON); |
| s->stat[MCS_INACTIVE_ANON] += val * PAGE_SIZE; |
| val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_ANON); |
| s->stat[MCS_ACTIVE_ANON] += val * PAGE_SIZE; |
| val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_FILE); |
| s->stat[MCS_INACTIVE_FILE] += val * PAGE_SIZE; |
| val = mem_cgroup_get_local_zonestat(mem, LRU_ACTIVE_FILE); |
| s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE; |
| val = mem_cgroup_get_local_zonestat(mem, LRU_UNEVICTABLE); |
| s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE; |
| } |
| |
| static void |
| mem_cgroup_get_total_stat(struct mem_cgroup *mem, struct mcs_total_stat *s) |
| { |
| struct mem_cgroup *iter; |
| |
| for_each_mem_cgroup_tree(iter, mem) |
| mem_cgroup_get_local_stat(iter, s); |
| } |
| |
| static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft, |
| struct cgroup_map_cb *cb) |
| { |
| struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont); |
| struct mcs_total_stat mystat; |
| int i; |
| |
| memset(&mystat, 0, sizeof(mystat)); |
| mem_cgroup_get_local_stat(mem_cont, &mystat); |
| |
| for (i = 0; i < NR_MCS_STAT; i++) { |
| if (i == MCS_SWAP && !do_swap_account) |
| continue; |
| cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]); |
| } |
| |
| /* Hierarchical information */ |
| { |
| unsigned long long limit, memsw_limit; |
| memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit); |
| cb->fill(cb, "hierarchical_memory_limit", limit); |
| if (do_swap_account) |
| cb->fill(cb, "hierarchical_memsw_limit", memsw_limit); |
| } |
| |
| memset(&mystat, 0, sizeof(mystat)); |
| mem_cgroup_get_total_stat(mem_cont, &mystat); |
| for (i = 0; i < NR_MCS_STAT; i++) { |
| if (i == MCS_SWAP && !do_swap_account) |
| continue; |
| cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]); |
| } |
| |
| #ifdef CONFIG_DEBUG_VM |
| cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL)); |
| |
| { |
| int nid, zid; |
| struct mem_cgroup_per_zone *mz; |
| unsigned long recent_rotated[2] = {0, 0}; |
| unsigned long recent_scanned[2] = {0, 0}; |
| |
| for_each_online_node(nid) |
| for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
| mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); |
| |
| recent_rotated[0] += |
| mz->reclaim_stat.recent_rotated[0]; |
| recent_rotated[1] += |
| mz->reclaim_stat.recent_rotated[1]; |
| recent_scanned[0] += |
| mz->reclaim_stat.recent_scanned[0]; |
| recent_scanned[1] += |
| mz->reclaim_stat.recent_scanned[1]; |
| } |
| cb->fill(cb, "recent_rotated_anon", recent_rotated[0]); |
| cb->fill(cb, "recent_rotated_file", recent_rotated[1]); |
| cb->fill(cb, "recent_scanned_anon", recent_scanned[0]); |
| cb->fill(cb, "recent_scanned_file", recent_scanned[1]); |
| } |
| #endif |
| |
| return 0; |
| } |
| |
| static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
| |
| return get_swappiness(memcg); |
| } |
| |
| static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft, |
| u64 val) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
| struct mem_cgroup *parent; |
| |
| if (val > 100) |
| return -EINVAL; |
| |
| if (cgrp->parent == NULL) |
| return -EINVAL; |
| |
| parent = mem_cgroup_from_cont(cgrp->parent); |
| |
| cgroup_lock(); |
| |
| /* If under hierarchy, only empty-root can set this value */ |
| if ((parent->use_hierarchy) || |
| (memcg->use_hierarchy && !list_empty(&cgrp->children))) { |
| cgroup_unlock(); |
| return -EINVAL; |
| } |
| |
| spin_lock(&memcg->reclaim_param_lock); |
| memcg->swappiness = val; |
| spin_unlock(&memcg->reclaim_param_lock); |
| |
| cgroup_unlock(); |
| |
| 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 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; |
| |
| return _a->threshold - _b->threshold; |
| } |
| |
| static int mem_cgroup_oom_notify_cb(struct mem_cgroup *mem) |
| { |
| struct mem_cgroup_eventfd_list *ev; |
| |
| list_for_each_entry(ev, &mem->oom_notify, list) |
| eventfd_signal(ev->eventfd, 1); |
| return 0; |
| } |
| |
| static void mem_cgroup_oom_notify(struct mem_cgroup *mem) |
| { |
| struct mem_cgroup *iter; |
| |
| for_each_mem_cgroup_tree(iter, mem) |
| mem_cgroup_oom_notify_cb(iter); |
| } |
| |
| static int mem_cgroup_usage_register_event(struct cgroup *cgrp, |
| struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
| struct mem_cgroup_thresholds *thresholds; |
| struct mem_cgroup_threshold_ary *new; |
| int 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; |
| } |
| } |
| |
| /* 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 *cgrp, |
| struct cftype *cft, struct eventfd_ctx *eventfd) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
| struct mem_cgroup_thresholds *thresholds; |
| struct mem_cgroup_threshold_ary *new; |
| int 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(); |
| |
| /* |
| * Something went wrong if we trying to unregister a threshold |
| * if we don't have thresholds |
| */ |
| BUG_ON(!thresholds); |
| |
| 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; |
| rcu_assign_pointer(thresholds->primary, new); |
| |
| /* To be sure that nobody uses thresholds */ |
| synchronize_rcu(); |
| |
| mutex_unlock(&memcg->thresholds_lock); |
| } |
| |
| static int mem_cgroup_oom_register_event(struct cgroup *cgrp, |
| struct cftype *cft, struct eventfd_ctx *eventfd, const char *args) |
| { |
| struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
| struct mem_cgroup_eventfd_list *event; |
| int type = MEMFILE_TYPE(cft->private); |
| |
| BUG_ON(type != _OOM_TYPE); |
| event = kmalloc(sizeof(*event), GFP_KERNEL); |
| if (!event) |
| return -ENOMEM; |
| |
| mutex_lock(&memcg_oom_mutex); |
| |
| event->eventfd = eventfd; |
| list_add(&event->list, &memcg->oom_notify); |
| |
| /* already in OOM ? */ |
| if (atomic_read(&memcg->oom_lock)) |
| eventfd_signal(eventfd, 1); |
| mutex_unlock(&memcg_oom_mutex); |
| |
| return 0; |
| } |
| |
| static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp, |
| struct cftype *cft, struct eventfd_ctx *eventfd) |
| { |
| struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); |
| struct mem_cgroup_eventfd_list *ev, *tmp; |
| int type = MEMFILE_TYPE(cft->private); |
| |
| BUG_ON(type != _OOM_TYPE); |
| |
| mutex_lock(&memcg_oom_mutex); |
| |
| list_for_each_entry_safe(ev, tmp, &mem->oom_notify, list) { |
| if (ev->eventfd == eventfd) { |
| list_del(&ev->list); |
| kfree(ev); |
| } |
| } |
| |
| mutex_unlock(&memcg_oom_mutex); |
| } |
| |
| static int mem_cgroup_oom_control_read(struct cgroup *cgrp, |
| struct cftype *cft, struct cgroup_map_cb *cb) |
| { |
| struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); |
| |
| cb->fill(cb, "oom_kill_disable", mem->oom_kill_disable); |
| |
| if (atomic_read(&mem->oom_lock)) |
| cb->fill(cb, "under_oom", 1); |
| else |
| cb->fill(cb, "under_oom", 0); |
| return 0; |
| } |
| |
| static int mem_cgroup_oom_control_write(struct cgroup *cgrp, |
| struct cftype *cft, u64 val) |
| { |
| struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); |
| struct mem_cgroup *parent; |
| |
| /* cannot set to root cgroup and only 0 and 1 are allowed */ |
| if (!cgrp->parent || !((val == 0) || (val == 1))) |
| return -EINVAL; |
| |
| parent = mem_cgroup_from_cont(cgrp->parent); |
| |
| cgroup_lock(); |
| /* oom-kill-disable is a flag for subhierarchy. */ |
| if ((parent->use_hierarchy) || |
| (mem->use_hierarchy && !list_empty(&cgrp->children))) { |
| cgroup_unlock(); |
| return -EINVAL; |
| } |
| mem->oom_kill_disable = val; |
| if (!val) |
| memcg_oom_recover(mem); |
| cgroup_unlock(); |
| return 0; |
| } |
| |
| static struct cftype mem_cgroup_files[] = { |
| { |
| .name = "usage_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
| .read_u64 = 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_u64 = mem_cgroup_read, |
| }, |
| { |
| .name = "limit_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
| .write_string = mem_cgroup_write, |
| .read_u64 = mem_cgroup_read, |
| }, |
| { |
| .name = "soft_limit_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), |
| .write_string = mem_cgroup_write, |
| .read_u64 = mem_cgroup_read, |
| }, |
| { |
| .name = "failcnt", |
| .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
| .trigger = mem_cgroup_reset, |
| .read_u64 = mem_cgroup_read, |
| }, |
| { |
| .name = "stat", |
| .read_map = mem_control_stat_show, |
| }, |
| { |
| .name = "force_empty", |
| .trigger = mem_cgroup_force_empty_write, |
| }, |
| { |
| .name = "use_hierarchy", |
| .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), |
| }, |
| }; |
| |
| #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
| static struct cftype memsw_cgroup_files[] = { |
| { |
| .name = "memsw.usage_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), |
| .read_u64 = mem_cgroup_read, |
| .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_u64 = mem_cgroup_read, |
| }, |
| { |
| .name = "memsw.limit_in_bytes", |
| .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), |
| .write_string = mem_cgroup_write, |
| .read_u64 = mem_cgroup_read, |
| }, |
| { |
| .name = "memsw.failcnt", |
| .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), |
| .trigger = mem_cgroup_reset, |
| .read_u64 = mem_cgroup_read, |
| }, |
| }; |
| |
| static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss) |
| { |
| if (!do_swap_account) |
| return 0; |
| return cgroup_add_files(cont, ss, memsw_cgroup_files, |
| ARRAY_SIZE(memsw_cgroup_files)); |
| }; |
| #else |
| static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss) |
| { |
| return 0; |
| } |
| #endif |
| |
| static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) |
| { |
| struct mem_cgroup_per_node *pn; |
| struct mem_cgroup_per_zone *mz; |
| enum lru_list l; |
| 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; |
| |
| mem->info.nodeinfo[node] = pn; |
| for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
| mz = &pn->zoneinfo[zone]; |
| for_each_lru(l) |
| INIT_LIST_HEAD(&mz->lists[l]); |
| mz->usage_in_excess = 0; |
| mz->on_tree = false; |
| mz->mem = mem; |
| } |
| return 0; |
| } |
| |
| static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) |
| { |
| kfree(mem->info.nodeinfo[node]); |
| } |
| |
| static struct mem_cgroup *mem_cgroup_alloc(void) |
| { |
| struct mem_cgroup *mem; |
| int size = sizeof(struct mem_cgroup); |
| |
| /* Can be very big if MAX_NUMNODES is very big */ |
| if (size < PAGE_SIZE) |
| mem = kzalloc(size, GFP_KERNEL); |
| else |
| mem = vzalloc(size); |
| |
| if (!mem) |
| return NULL; |
| |
| mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu); |
| if (!mem->stat) |
| goto out_free; |
| spin_lock_init(&mem->pcp_counter_lock); |
| return mem; |
| |
| out_free: |
| if (size < PAGE_SIZE) |
| kfree(mem); |
| else |
| vfree(mem); |
| 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 *mem) |
| { |
| int node; |
| |
| mem_cgroup_remove_from_trees(mem); |
| free_css_id(&mem_cgroup_subsys, &mem->css); |
| |
| for_each_node_state(node, N_POSSIBLE) |
| free_mem_cgroup_per_zone_info(mem, node); |
| |
| free_percpu(mem->stat); |
| if (sizeof(struct mem_cgroup) < PAGE_SIZE) |
| kfree(mem); |
| else |
| vfree(mem); |
| } |
| |
| static void mem_cgroup_get(struct mem_cgroup *mem) |
| { |
| atomic_inc(&mem->refcnt); |
| } |
| |
| static void __mem_cgroup_put(struct mem_cgroup *mem, int count) |
| { |
| if (atomic_sub_and_test(count, &mem->refcnt)) { |
| struct mem_cgroup *parent = parent_mem_cgroup(mem); |
| __mem_cgroup_free(mem); |
| if (parent) |
| mem_cgroup_put(parent); |
| } |
| } |
| |
| static void mem_cgroup_put(struct mem_cgroup *mem) |
| { |
| __mem_cgroup_put(mem, 1); |
| } |
| |
| /* |
| * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. |
| */ |
| static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem) |
| { |
| if (!mem->res.parent) |
| return NULL; |
| return mem_cgroup_from_res_counter(mem->res.parent, res); |
| } |
| |
| #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
| static void __init enable_swap_cgroup(void) |
| { |
| if (!mem_cgroup_disabled() && really_do_swap_account) |
| do_swap_account = 1; |
| } |
| #else |
| static void __init enable_swap_cgroup(void) |
| { |
| } |
| #endif |
| |
| static int 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_state(node, N_POSSIBLE) { |
| tmp = node; |
| if (!node_state(node, N_NORMAL_MEMORY)) |
| tmp = -1; |
| rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp); |
| if (!rtpn) |
| return 1; |
| |
| 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); |
| } |
| } |
| return 0; |
| } |
| |
| static struct cgroup_subsys_state * __ref |
| mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) |
| { |
| struct mem_cgroup *mem, *parent; |
| long error = -ENOMEM; |
| int node; |
| |
| mem = mem_cgroup_alloc(); |
| if (!mem) |
| return ERR_PTR(error); |
| |
| for_each_node_state(node, N_POSSIBLE) |
| if (alloc_mem_cgroup_per_zone_info(mem, node)) |
| goto free_out; |
| |
| /* root ? */ |
| if (cont->parent == NULL) { |
| int cpu; |
| enable_swap_cgroup(); |
| parent = NULL; |
| root_mem_cgroup = mem; |
| if (mem_cgroup_soft_limit_tree_init()) |
| goto free_out; |
| for_each_possible_cpu(cpu) { |
| struct memcg_stock_pcp *stock = |
| &per_cpu(memcg_stock, cpu); |
| INIT_WORK(&stock->work, drain_local_stock); |
| } |
| hotcpu_notifier(memcg_cpu_hotplug_callback, 0); |
| } else { |
| parent = mem_cgroup_from_cont(cont->parent); |
| mem->use_hierarchy = parent->use_hierarchy; |
| mem->oom_kill_disable = parent->oom_kill_disable; |
| } |
| |
| if (parent && parent->use_hierarchy) { |
| res_counter_init(&mem->res, &parent->res); |
| res_counter_init(&mem->memsw, &parent->memsw); |
| /* |
| * We increment refcnt of the parent to ensure that we can |
| * safely access it on res_counter_charge/uncharge. |
| * This refcnt will be decremented when freeing this |
| * mem_cgroup(see mem_cgroup_put). |
| */ |
| mem_cgroup_get(parent); |
| } else { |
| res_counter_init(&mem->res, NULL); |
| res_counter_init(&mem->memsw, NULL); |
| } |
| mem->last_scanned_child = 0; |
| spin_lock_init(&mem->reclaim_param_lock); |
| INIT_LIST_HEAD(&mem->oom_notify); |
| |
| if (parent) |
| mem->swappiness = get_swappiness(parent); |
| atomic_set(&mem->refcnt, 1); |
| mem->move_charge_at_immigrate = 0; |
| mutex_init(&mem->thresholds_lock); |
| return &mem->css; |
| free_out: |
| __mem_cgroup_free(mem); |
| root_mem_cgroup = NULL; |
| return ERR_PTR(error); |
| } |
| |
| static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss, |
| struct cgroup *cont) |
| { |
| struct mem_cgroup *mem = mem_cgroup_from_cont(cont); |
| |
| return mem_cgroup_force_empty(mem, false); |
| } |
| |
| static void mem_cgroup_destroy(struct cgroup_subsys *ss, |
| struct cgroup *cont) |
| { |
| struct mem_cgroup *mem = mem_cgroup_from_cont(cont); |
| |
| mem_cgroup_put(mem); |
| } |
| |
| static int mem_cgroup_populate(struct cgroup_subsys *ss, |
| struct cgroup *cont) |
| { |
| int ret; |
| |
| ret = cgroup_add_files(cont, ss, mem_cgroup_files, |
| ARRAY_SIZE(mem_cgroup_files)); |
| |
| if (!ret) |
| ret = register_memsw_files(cont, ss); |
| return ret; |
| } |
| |
| #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 *mem = mc.to; |
| |
| if (mem_cgroup_is_root(mem)) { |
| 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; |
| /* |
| * "mem" 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(&mem->res, PAGE_SIZE * count, &dummy)) |
| goto one_by_one; |
| if (do_swap_account && res_counter_charge(&mem->memsw, |
| PAGE_SIZE * count, &dummy)) { |
| res_counter_uncharge(&mem->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, &mem, false, |
| PAGE_SIZE); |
| if (ret || !mem) |
| /* mem_cgroup_clear_mc() will do uncharge later */ |
| return -ENOMEM; |
| mc.precharge++; |
| } |
| return ret; |
| } |
| |
| /** |
| * is_target_pte_for_mc - check a pte whether it is valid for move 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, /* not used */ |
| 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() || page_mapcount(page) > 2) |
| return NULL; |
| } else if (!move_file()) |
| /* we ignore mapcount for file pages */ |
| return NULL; |
| if (!get_page_unless_zero(page)) |
| return NULL; |
| |
| return page; |
| } |
| |
| static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, |
| unsigned long addr, pte_t ptent, swp_entry_t *entry) |
| { |
| int usage_count; |
| struct page *page = NULL; |
| swp_entry_t ent = pte_to_swp_entry(ptent); |
| |
| if (!move_anon() || non_swap_entry(ent)) |
| return NULL; |
| usage_count = mem_cgroup_count_swap_user(ent, &page); |
| if (usage_count > 1) { /* we don't move shared anon */ |
| if (page) |
| put_page(page); |
| return NULL; |
| } |
| if (do_swap_account) |
| entry->val = ent.val; |
| |
| return page; |
| } |
| |
| 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 inode *inode; |
| struct address_space *mapping; |
| pgoff_t pgoff; |
| |
| if (!vma->vm_file) /* anonymous vma */ |
| return NULL; |
| if (!move_file()) |
| return NULL; |
| |
| inode = vma->vm_file->f_path.dentry->d_inode; |
| 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). */ |
| if (!mapping_cap_swap_backed(mapping)) { /* normal file */ |
| page = find_get_page(mapping, pgoff); |
| } else { /* shmem/tmpfs file. we should take account of swap too. */ |
| swp_entry_t ent; |
| mem_cgroup_get_shmem_target(inode, pgoff, &page, &ent); |
| if (do_swap_account) |
| entry->val = ent.val; |
| } |
| |
| return page; |
| } |
| |
| static int is_target_pte_for_mc(struct vm_area_struct *vma, |
| unsigned long addr, pte_t ptent, union mc_target *target) |
| { |
| struct page *page = NULL; |
| struct page_cgroup *pc; |
| int ret = 0; |
| 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 0; |
| 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(ent)) { |
| ret = MC_TARGET_SWAP; |
| if (target) |
| target->ent = ent; |
| } |
| return ret; |
| } |
| |
| 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; |
| |
| split_huge_page_pmd(walk->mm, pmd); |
| |
| pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
| for (; addr != end; pte++, addr += PAGE_SIZE) |
| if (is_target_pte_for_mc(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; |
| |
| /* 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); |
| __mem_cgroup_put(mc.from, mc.moved_swap); |
| |
| 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 mem_cgroup_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 *ss, |
| struct cgroup *cgroup, |
| struct task_struct *p, |
| bool threadgroup) |
| { |
| int ret = 0; |
| struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup); |
| |
| if (mem->move_charge_at_immigrate) { |
| struct mm_struct *mm; |
| struct mem_cgroup *from = mem_cgroup_from_task(p); |
| |
| VM_BUG_ON(from == mem); |
| |
| 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 = mem; |
| 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 *ss, |
| struct cgroup *cgroup, |
| struct task_struct *p, |
| bool threadgroup) |
| { |
| 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; |
| |
| split_huge_page_pmd(walk->mm, pmd); |
| retry: |
| pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
| for (; addr != end; addr += PAGE_SIZE) { |
| pte_t ptent = *(pte++); |
| union mc_target target; |
| int type; |
| struct page *page; |
| struct page_cgroup *pc; |
| swp_entry_t ent; |
| |
| if (!mc.precharge) |
| break; |
| |
| type = is_target_pte_for_mc(vma, addr, ptent, &target); |
| switch (type) { |
| case MC_TARGET_PAGE: |
| page = target.page; |
| if (isolate_lru_page(page)) |
| goto put; |
| pc = lookup_page_cgroup(page); |
| if (!mem_cgroup_move_account(pc, |
| mc.from, mc.to, false, PAGE_SIZE)) { |
| mc.precharge--; |
| /* we uncharge from mc.from later. */ |
| mc.moved_charge++; |
| } |
| putback_lru_page(page); |
| put: /* is_target_pte_for_mc() 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, false)) { |
| 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 *ss, |
| struct cgroup *cont, |
| struct cgroup *old_cont, |
| struct task_struct *p, |
| bool threadgroup) |
| { |
| struct mm_struct *mm; |
| |
| if (!mc.to) |
| /* no need to move charge */ |
| return; |
| |
| mm = get_task_mm(p); |
| if (mm) { |
| mem_cgroup_move_charge(mm); |
| mmput(mm); |
| } |
| mem_cgroup_clear_mc(); |
| } |
| #else /* !CONFIG_MMU */ |
| static int mem_cgroup_can_attach(struct cgroup_subsys *ss, |
| struct cgroup *cgroup, |
| struct task_struct *p, |
| bool threadgroup) |
| { |
| return 0; |
| } |
| static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss, |
| struct cgroup *cgroup, |
| struct task_struct *p, |
| bool threadgroup) |
| { |
| } |
| static void mem_cgroup_move_task(struct cgroup_subsys *ss, |
| struct cgroup *cont, |
| struct cgroup *old_cont, |
| struct task_struct *p, |
| bool threadgroup) |
| { |
| } |
| #endif |
| |
| struct cgroup_subsys mem_cgroup_subsys = { |
| .name = "memory", |
| .subsys_id = mem_cgroup_subsys_id, |
| .create = mem_cgroup_create, |
| .pre_destroy = mem_cgroup_pre_destroy, |
| .destroy = mem_cgroup_destroy, |
| .populate = mem_cgroup_populate, |
| .can_attach = mem_cgroup_can_attach, |
| .cancel_attach = mem_cgroup_cancel_attach, |
| .attach = mem_cgroup_move_task, |
| .early_init = 0, |
| .use_id = 1, |
| }; |
| |
| #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
| static int __init enable_swap_account(char *s) |
| { |
| /* consider enabled if no parameter or 1 is given */ |
| if (!(*s) || !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 int __init disable_swap_account(char *s) |
| { |
| printk_once("noswapaccount is deprecated and will be removed in 2.6.40. Use swapaccount=0 instead\n"); |
| enable_swap_account("=0"); |
| return 1; |
| } |
| __setup("noswapaccount", disable_swap_account); |
| #endif |