From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001 From: hc <hc@nodka.com> Date: Tue, 20 Feb 2024 01:20:52 +0000 Subject: [PATCH] add new system file --- kernel/mm/memcontrol.c | 3521 ++++++++++++++++++++++++++++++++++++----------------------- 1 files changed, 2,150 insertions(+), 1,371 deletions(-) diff --git a/kernel/mm/memcontrol.c b/kernel/mm/memcontrol.c index 921e450..b6f6bfc 100644 --- a/kernel/mm/memcontrol.c +++ b/kernel/mm/memcontrol.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* memcontrol.c - Memory Controller * * Copyright IBM Corporation, 2007 @@ -19,26 +20,17 @@ * Lockless page tracking & accounting * Unified hierarchy configuration model * Copyright (C) 2015 Red Hat, Inc., Johannes Weiner - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. */ #include <linux/page_counter.h> #include <linux/memcontrol.h> #include <linux/cgroup.h> -#include <linux/mm.h> +#include <linux/pagewalk.h> #include <linux/sched/mm.h> #include <linux/shmem_fs.h> #include <linux/hugetlb.h> #include <linux/pagemap.h> +#include <linux/vm_event_item.h> #include <linux/smp.h> #include <linux/page-flags.h> #include <linux/backing-dev.h> @@ -65,22 +57,26 @@ #include <linux/lockdep.h> #include <linux/file.h> #include <linux/tracehook.h> +#include <linux/psi.h> +#include <linux/seq_buf.h> #include "internal.h" #include <net/sock.h> #include <net/ip.h> #include "slab.h" -#include <linux/locallock.h> #include <linux/uaccess.h> #include <trace/events/vmscan.h> +#include <trace/hooks/mm.h> struct cgroup_subsys memory_cgrp_subsys __read_mostly; EXPORT_SYMBOL(memory_cgrp_subsys); struct mem_cgroup *root_mem_cgroup __read_mostly; +EXPORT_SYMBOL_GPL(root_mem_cgroup); -#define MEM_CGROUP_RECLAIM_RETRIES 5 +/* Active memory cgroup to use from an interrupt context */ +DEFINE_PER_CPU(struct mem_cgroup *, int_active_memcg); /* Socket memory accounting disabled? */ static bool cgroup_memory_nosocket; @@ -90,30 +86,23 @@ /* Whether the swap controller is active */ #ifdef CONFIG_MEMCG_SWAP -int do_swap_account __read_mostly; +bool cgroup_memory_noswap __read_mostly; #else -#define do_swap_account 0 +#define cgroup_memory_noswap 1 #endif -static DEFINE_LOCAL_IRQ_LOCK(event_lock); +#ifdef CONFIG_CGROUP_WRITEBACK +static DECLARE_WAIT_QUEUE_HEAD(memcg_cgwb_frn_waitq); +#endif /* Whether legacy memory+swap accounting is active */ static bool do_memsw_account(void) { - return !cgroup_subsys_on_dfl(memory_cgrp_subsys) && do_swap_account; + return !cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_noswap; } - -static const char *const mem_cgroup_lru_names[] = { - "inactive_anon", - "active_anon", - "inactive_file", - "active_file", - "unevictable", -}; #define THRESHOLDS_EVENTS_TARGET 128 #define SOFTLIMIT_EVENTS_TARGET 1024 -#define NUMAINFO_EVENTS_TARGET 1024 /* * Cgroups above their limits are maintained in a RB-Tree, independent of @@ -213,14 +202,6 @@ #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 #define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2 -enum charge_type { - MEM_CGROUP_CHARGE_TYPE_CACHE = 0, - MEM_CGROUP_CHARGE_TYPE_ANON, - MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ - MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ - NR_CHARGE_TYPE, -}; - /* for encoding cft->private value on file */ enum res_type { _MEM, @@ -251,7 +232,7 @@ iter != NULL; \ iter = mem_cgroup_iter(NULL, iter, NULL)) -static inline bool should_force_charge(void) +static inline bool task_is_dying(void) { return tsk_is_oom_victim(current) || fatal_signal_pending(current) || (current->flags & PF_EXITING); @@ -271,8 +252,100 @@ } #ifdef CONFIG_MEMCG_KMEM +static DEFINE_SPINLOCK(objcg_lock); + +static void obj_cgroup_release(struct percpu_ref *ref) +{ + struct obj_cgroup *objcg = container_of(ref, struct obj_cgroup, refcnt); + struct mem_cgroup *memcg; + unsigned int nr_bytes; + unsigned int nr_pages; + unsigned long flags; + + /* + * At this point all allocated objects are freed, and + * objcg->nr_charged_bytes can't have an arbitrary byte value. + * However, it can be PAGE_SIZE or (x * PAGE_SIZE). + * + * The following sequence can lead to it: + * 1) CPU0: objcg == stock->cached_objcg + * 2) CPU1: we do a small allocation (e.g. 92 bytes), + * PAGE_SIZE bytes are charged + * 3) CPU1: a process from another memcg is allocating something, + * the stock if flushed, + * objcg->nr_charged_bytes = PAGE_SIZE - 92 + * 5) CPU0: we do release this object, + * 92 bytes are added to stock->nr_bytes + * 6) CPU0: stock is flushed, + * 92 bytes are added to objcg->nr_charged_bytes + * + * In the result, nr_charged_bytes == PAGE_SIZE. + * This page will be uncharged in obj_cgroup_release(). + */ + nr_bytes = atomic_read(&objcg->nr_charged_bytes); + WARN_ON_ONCE(nr_bytes & (PAGE_SIZE - 1)); + nr_pages = nr_bytes >> PAGE_SHIFT; + + spin_lock_irqsave(&objcg_lock, flags); + memcg = obj_cgroup_memcg(objcg); + if (nr_pages) + __memcg_kmem_uncharge(memcg, nr_pages); + list_del(&objcg->list); + mem_cgroup_put(memcg); + spin_unlock_irqrestore(&objcg_lock, flags); + + percpu_ref_exit(ref); + kfree_rcu(objcg, rcu); +} + +static struct obj_cgroup *obj_cgroup_alloc(void) +{ + struct obj_cgroup *objcg; + int ret; + + objcg = kzalloc(sizeof(struct obj_cgroup), GFP_KERNEL); + if (!objcg) + return NULL; + + ret = percpu_ref_init(&objcg->refcnt, obj_cgroup_release, 0, + GFP_KERNEL); + if (ret) { + kfree(objcg); + return NULL; + } + INIT_LIST_HEAD(&objcg->list); + return objcg; +} + +static void memcg_reparent_objcgs(struct mem_cgroup *memcg, + struct mem_cgroup *parent) +{ + struct obj_cgroup *objcg, *iter; + + objcg = rcu_replace_pointer(memcg->objcg, NULL, true); + + spin_lock_irq(&objcg_lock); + + /* Move active objcg to the parent's list */ + xchg(&objcg->memcg, parent); + css_get(&parent->css); + list_add(&objcg->list, &parent->objcg_list); + + /* Move already reparented objcgs to the parent's list */ + list_for_each_entry(iter, &memcg->objcg_list, list) { + css_get(&parent->css); + xchg(&iter->memcg, parent); + css_put(&memcg->css); + } + list_splice(&memcg->objcg_list, &parent->objcg_list); + + spin_unlock_irq(&objcg_lock); + + percpu_ref_kill(&objcg->refcnt); +} + /* - * This will be the memcg's index in each cache's ->memcg_params.memcg_caches. + * This will be used as a shrinker list's index. * The main reason for not using cgroup id for this: * this works better in sparse environments, where we have a lot of memcgs, * but only a few kmem-limited. Or also, if we have, for instance, 200 @@ -315,14 +388,13 @@ /* * A lot of the calls to the cache allocation functions are expected to be - * inlined by the compiler. Since the calls to memcg_kmem_get_cache are + * inlined by the compiler. Since the calls to memcg_slab_pre_alloc_hook() are * conditional to this static branch, we'll have to allow modules that does * kmem_cache_alloc and the such to see this symbol as well */ DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key); EXPORT_SYMBOL(memcg_kmem_enabled_key); - -struct workqueue_struct *memcg_kmem_cache_wq; +#endif static int memcg_shrinker_map_size; static DEFINE_MUTEX(memcg_shrinker_map_mutex); @@ -347,7 +419,7 @@ if (!old) return 0; - new = kvmalloc(sizeof(*new) + size, GFP_KERNEL); + new = kvmalloc_node(sizeof(*new) + size, GFP_KERNEL, nid); if (!new) return -ENOMEM; @@ -391,7 +463,7 @@ mutex_lock(&memcg_shrinker_map_mutex); size = memcg_shrinker_map_size; for_each_node(nid) { - map = kvzalloc(sizeof(*map) + size, GFP_KERNEL); + map = kvzalloc_node(sizeof(*map) + size, GFP_KERNEL, nid); if (!map) { memcg_free_shrinker_maps(memcg); ret = -ENOMEM; @@ -448,14 +520,6 @@ } } -#else /* CONFIG_MEMCG_KMEM */ -static int memcg_alloc_shrinker_maps(struct mem_cgroup *memcg) -{ - return 0; -} -static void memcg_free_shrinker_maps(struct mem_cgroup *memcg) { } -#endif /* CONFIG_MEMCG_KMEM */ - /** * mem_cgroup_css_from_page - css of the memcg associated with a page * @page: page of interest @@ -498,7 +562,17 @@ unsigned long ino = 0; rcu_read_lock(); - memcg = READ_ONCE(page->mem_cgroup); + memcg = page->mem_cgroup; + + /* + * The lowest bit set means that memcg isn't a valid + * memcg pointer, but a obj_cgroups pointer. + * In this case the page is shared and doesn't belong + * to any specific memory cgroup. + */ + if ((unsigned long) memcg & 0x1UL) + memcg = NULL; + while (memcg && !(memcg->css.flags & CSS_ONLINE)) memcg = parent_mem_cgroup(memcg); if (memcg) @@ -674,7 +748,7 @@ */ __mem_cgroup_remove_exceeded(mz, mctz); if (!soft_limit_excess(mz->memcg) || - !css_tryget_online(&mz->memcg->css)) + !css_tryget(&mz->memcg->css)) goto retry; done: return mz; @@ -691,33 +765,186 @@ return mz; } -static unsigned long memcg_sum_events(struct mem_cgroup *memcg, - int event) +/** + * __mod_memcg_state - update cgroup memory statistics + * @memcg: the memory cgroup + * @idx: the stat item - can be enum memcg_stat_item or enum node_stat_item + * @val: delta to add to the counter, can be negative + */ +void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val) { - return atomic_long_read(&memcg->events[event]); + long x, threshold = MEMCG_CHARGE_BATCH; + + if (mem_cgroup_disabled()) + return; + + if (memcg_stat_item_in_bytes(idx)) + threshold <<= PAGE_SHIFT; + + x = val + __this_cpu_read(memcg->vmstats_percpu->stat[idx]); + if (unlikely(abs(x) > threshold)) { + struct mem_cgroup *mi; + + /* + * Batch local counters to keep them in sync with + * the hierarchical ones. + */ + __this_cpu_add(memcg->vmstats_local->stat[idx], x); + for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) + atomic_long_add(x, &mi->vmstats[idx]); + x = 0; + } + __this_cpu_write(memcg->vmstats_percpu->stat[idx], x); +} + +static struct mem_cgroup_per_node * +parent_nodeinfo(struct mem_cgroup_per_node *pn, int nid) +{ + struct mem_cgroup *parent; + + parent = parent_mem_cgroup(pn->memcg); + if (!parent) + return NULL; + return mem_cgroup_nodeinfo(parent, nid); +} + +void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, + int val) +{ + struct mem_cgroup_per_node *pn; + struct mem_cgroup *memcg; + long x, threshold = MEMCG_CHARGE_BATCH; + + pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec); + memcg = pn->memcg; + + /* Update memcg */ + __mod_memcg_state(memcg, idx, val); + + /* Update lruvec */ + __this_cpu_add(pn->lruvec_stat_local->count[idx], val); + + if (vmstat_item_in_bytes(idx)) + threshold <<= PAGE_SHIFT; + + x = val + __this_cpu_read(pn->lruvec_stat_cpu->count[idx]); + if (unlikely(abs(x) > threshold)) { + pg_data_t *pgdat = lruvec_pgdat(lruvec); + struct mem_cgroup_per_node *pi; + + for (pi = pn; pi; pi = parent_nodeinfo(pi, pgdat->node_id)) + atomic_long_add(x, &pi->lruvec_stat[idx]); + x = 0; + } + __this_cpu_write(pn->lruvec_stat_cpu->count[idx], x); +} + +/** + * __mod_lruvec_state - update lruvec memory statistics + * @lruvec: the lruvec + * @idx: the stat item + * @val: delta to add to the counter, can be negative + * + * The lruvec is the intersection of the NUMA node and a cgroup. This + * function updates the all three counters that are affected by a + * change of state at this level: per-node, per-cgroup, per-lruvec. + */ +void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, + int val) +{ + /* Update node */ + __mod_node_page_state(lruvec_pgdat(lruvec), idx, val); + + /* Update memcg and lruvec */ + if (!mem_cgroup_disabled()) + __mod_memcg_lruvec_state(lruvec, idx, val); +} +EXPORT_SYMBOL_GPL(__mod_lruvec_state); + +void __mod_lruvec_slab_state(void *p, enum node_stat_item idx, int val) +{ + pg_data_t *pgdat = page_pgdat(virt_to_page(p)); + struct mem_cgroup *memcg; + struct lruvec *lruvec; + + rcu_read_lock(); + memcg = mem_cgroup_from_obj(p); + + /* + * Untracked pages have no memcg, no lruvec. Update only the + * node. If we reparent the slab objects to the root memcg, + * when we free the slab object, we need to update the per-memcg + * vmstats to keep it correct for the root memcg. + */ + if (!memcg) { + __mod_node_page_state(pgdat, idx, val); + } else { + lruvec = mem_cgroup_lruvec(memcg, pgdat); + __mod_lruvec_state(lruvec, idx, val); + } + rcu_read_unlock(); +} + +void mod_memcg_obj_state(void *p, int idx, int val) +{ + struct mem_cgroup *memcg; + + rcu_read_lock(); + memcg = mem_cgroup_from_obj(p); + if (memcg) + mod_memcg_state(memcg, idx, val); + rcu_read_unlock(); +} + +/** + * __count_memcg_events - account VM events in a cgroup + * @memcg: the memory cgroup + * @idx: the event item + * @count: the number of events that occured + */ +void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx, + unsigned long count) +{ + unsigned long x; + + if (mem_cgroup_disabled()) + return; + + x = count + __this_cpu_read(memcg->vmstats_percpu->events[idx]); + if (unlikely(x > MEMCG_CHARGE_BATCH)) { + struct mem_cgroup *mi; + + /* + * Batch local counters to keep them in sync with + * the hierarchical ones. + */ + __this_cpu_add(memcg->vmstats_local->events[idx], x); + for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) + atomic_long_add(x, &mi->vmevents[idx]); + x = 0; + } + __this_cpu_write(memcg->vmstats_percpu->events[idx], x); +} + +static unsigned long memcg_events(struct mem_cgroup *memcg, int event) +{ + return atomic_long_read(&memcg->vmevents[event]); +} + +static unsigned long memcg_events_local(struct mem_cgroup *memcg, int event) +{ + long x = 0; + int cpu; + + for_each_possible_cpu(cpu) + x += per_cpu(memcg->vmstats_local->events[event], cpu); + return x; } static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, struct page *page, - bool compound, int nr_pages) + int nr_pages) { - /* - * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is - * counted as CACHE even if it's on ANON LRU. - */ - if (PageAnon(page)) - __mod_memcg_state(memcg, MEMCG_RSS, nr_pages); - else { - __mod_memcg_state(memcg, MEMCG_CACHE, nr_pages); - if (PageSwapBacked(page)) - __mod_memcg_state(memcg, NR_SHMEM, nr_pages); - } - - if (compound) { - VM_BUG_ON_PAGE(!PageTransHuge(page), page); - __mod_memcg_state(memcg, MEMCG_RSS_HUGE, nr_pages); - } - /* pagein of a big page is an event. So, ignore page size */ if (nr_pages > 0) __count_memcg_events(memcg, PGPGIN, 1); @@ -726,35 +953,7 @@ nr_pages = -nr_pages; /* for event */ } - __this_cpu_add(memcg->stat_cpu->nr_page_events, nr_pages); -} - -unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, - int nid, unsigned int lru_mask) -{ - struct lruvec *lruvec = mem_cgroup_lruvec(NODE_DATA(nid), memcg); - unsigned long nr = 0; - enum lru_list lru; - - VM_BUG_ON((unsigned)nid >= nr_node_ids); - - for_each_lru(lru) { - if (!(BIT(lru) & lru_mask)) - continue; - nr += mem_cgroup_get_lru_size(lruvec, lru); - } - return nr; -} - -static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, - unsigned int lru_mask) -{ - unsigned long nr = 0; - int nid; - - for_each_node_state(nid, N_MEMORY) - nr += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask); - return nr; + __this_cpu_add(memcg->vmstats_percpu->nr_page_events, nr_pages); } static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, @@ -762,8 +961,8 @@ { unsigned long val, next; - val = __this_cpu_read(memcg->stat_cpu->nr_page_events); - next = __this_cpu_read(memcg->stat_cpu->targets[target]); + val = __this_cpu_read(memcg->vmstats_percpu->nr_page_events); + next = __this_cpu_read(memcg->vmstats_percpu->targets[target]); /* from time_after() in jiffies.h */ if ((long)(next - val) < 0) { switch (target) { @@ -773,13 +972,10 @@ case MEM_CGROUP_TARGET_SOFTLIMIT: next = val + SOFTLIMIT_EVENTS_TARGET; break; - case MEM_CGROUP_TARGET_NUMAINFO: - next = val + NUMAINFO_EVENTS_TARGET; - break; default: break; } - __this_cpu_write(memcg->stat_cpu->targets[target], next); + __this_cpu_write(memcg->vmstats_percpu->targets[target], next); return true; } return false; @@ -795,21 +991,12 @@ if (unlikely(mem_cgroup_event_ratelimit(memcg, MEM_CGROUP_TARGET_THRESH))) { bool do_softlimit; - bool do_numainfo __maybe_unused; do_softlimit = mem_cgroup_event_ratelimit(memcg, MEM_CGROUP_TARGET_SOFTLIMIT); -#if MAX_NUMNODES > 1 - do_numainfo = mem_cgroup_event_ratelimit(memcg, - MEM_CGROUP_TARGET_NUMAINFO); -#endif mem_cgroup_threshold(memcg); if (unlikely(do_softlimit)) mem_cgroup_update_tree(memcg, page); -#if MAX_NUMNODES > 1 - if (unlikely(do_numainfo)) - atomic_inc(&memcg->numainfo_events); -#endif } } @@ -877,27 +1064,60 @@ return NULL; rcu_read_lock(); - if (!memcg || !css_tryget_online(&memcg->css)) + /* Page should not get uncharged and freed memcg under us. */ + if (!memcg || WARN_ON_ONCE(!css_tryget(&memcg->css))) memcg = root_mem_cgroup; rcu_read_unlock(); return memcg; } EXPORT_SYMBOL(get_mem_cgroup_from_page); +static __always_inline struct mem_cgroup *active_memcg(void) +{ + if (in_interrupt()) + return this_cpu_read(int_active_memcg); + else + return current->active_memcg; +} + +static __always_inline struct mem_cgroup *get_active_memcg(void) +{ + struct mem_cgroup *memcg; + + rcu_read_lock(); + memcg = active_memcg(); + /* remote memcg must hold a ref. */ + if (memcg && WARN_ON_ONCE(!css_tryget(&memcg->css))) + memcg = root_mem_cgroup; + rcu_read_unlock(); + + return memcg; +} + +static __always_inline bool memcg_kmem_bypass(void) +{ + /* Allow remote memcg charging from any context. */ + if (unlikely(active_memcg())) + return false; + + /* Memcg to charge can't be determined. */ + if (in_interrupt() || !current->mm || (current->flags & PF_KTHREAD)) + return true; + + return false; +} + /** - * If current->active_memcg is non-NULL, do not fallback to current->mm->memcg. + * If active memcg is set, do not fallback to current->mm->memcg. */ static __always_inline struct mem_cgroup *get_mem_cgroup_from_current(void) { - if (unlikely(current->active_memcg)) { - struct mem_cgroup *memcg = root_mem_cgroup; + if (memcg_kmem_bypass()) + return NULL; - rcu_read_lock(); - if (css_tryget_online(¤t->active_memcg->css)) - memcg = current->active_memcg; - rcu_read_unlock(); - return memcg; - } + if (unlikely(active_memcg())) + return get_active_memcg(); + return get_mem_cgroup_from_mm(current->mm); } @@ -914,15 +1134,15 @@ * invocations for reference counting, or use mem_cgroup_iter_break() * to cancel a hierarchy walk before the round-trip is complete. * - * Reclaimers can specify a node and a priority level in @reclaim to - * divide up the memcgs in the hierarchy among all concurrent - * reclaimers operating on the same node and priority. + * Reclaimers can specify a node in @reclaim to divide up the memcgs + * in the hierarchy among all concurrent reclaimers operating on the + * same node. */ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, struct mem_cgroup *prev, struct mem_cgroup_reclaim_cookie *reclaim) { - struct mem_cgroup_reclaim_iter *uninitialized_var(iter); + struct mem_cgroup_reclaim_iter *iter; struct cgroup_subsys_state *css = NULL; struct mem_cgroup *memcg = NULL; struct mem_cgroup *pos = NULL; @@ -948,7 +1168,7 @@ struct mem_cgroup_per_node *mz; mz = mem_cgroup_nodeinfo(root, reclaim->pgdat->node_id); - iter = &mz->iter[reclaim->priority]; + iter = &mz->iter; if (prev && reclaim->generation != iter->generation) goto out_unlock; @@ -1048,15 +1268,11 @@ struct mem_cgroup_reclaim_iter *iter; struct mem_cgroup_per_node *mz; int nid; - int i; for_each_node(nid) { mz = mem_cgroup_nodeinfo(from, nid); - for (i = 0; i <= DEF_PRIORITY; i++) { - iter = &mz->iter[i]; - cmpxchg(&iter->position, - dead_memcg, NULL); - } + iter = &mz->iter; + cmpxchg(&iter->position, dead_memcg, NULL); } } @@ -1106,7 +1322,7 @@ struct css_task_iter it; struct task_struct *task; - css_task_iter_start(&iter->css, 0, &it); + css_task_iter_start(&iter->css, CSS_TASK_ITER_PROCS, &it); while (!ret && (task = css_task_iter_next(&it))) ret = fn(task, arg); css_task_iter_end(&it); @@ -1123,9 +1339,8 @@ * @page: the page * @pgdat: pgdat of the page * - * This function is only safe when following the LRU page isolation - * and putback protocol: the LRU lock must be held, and the page must - * either be PageLRU() or the caller must have isolated/allocated it. + * This function relies on page->mem_cgroup being stable - see the + * access rules in commit_charge(). */ struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct pglist_data *pgdat) { @@ -1134,7 +1349,7 @@ struct lruvec *lruvec; if (mem_cgroup_disabled()) { - lruvec = &pgdat->lruvec; + lruvec = &pgdat->__lruvec; goto out; } @@ -1158,6 +1373,38 @@ lruvec->pgdat = pgdat; return lruvec; } + +struct lruvec *page_to_lruvec(struct page *page, pg_data_t *pgdat) +{ + struct lruvec *lruvec; + + lruvec = mem_cgroup_page_lruvec(page, pgdat); + + return lruvec; +} +EXPORT_SYMBOL_GPL(page_to_lruvec); + +void do_traversal_all_lruvec(void) +{ + pg_data_t *pgdat; + + for_each_online_pgdat(pgdat) { + struct mem_cgroup *memcg = NULL; + + spin_lock_irq(&pgdat->lru_lock); + memcg = mem_cgroup_iter(NULL, NULL, NULL); + do { + struct lruvec *lruvec = mem_cgroup_lruvec(memcg, pgdat); + + trace_android_vh_do_traversal_lruvec(lruvec); + + memcg = mem_cgroup_iter(NULL, memcg, NULL); + } while (memcg); + + spin_unlock_irq(&pgdat->lru_lock); + } +} +EXPORT_SYMBOL_GPL(do_traversal_all_lruvec); /** * mem_cgroup_update_lru_size - account for adding or removing an lru page @@ -1197,32 +1444,7 @@ if (nr_pages > 0) *lru_size += nr_pages; } - -bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg) -{ - struct mem_cgroup *task_memcg; - struct task_struct *p; - bool ret; - - p = find_lock_task_mm(task); - if (p) { - task_memcg = get_mem_cgroup_from_mm(p->mm); - task_unlock(p); - } else { - /* - * All threads may have already detached their mm's, but the oom - * killer still needs to detect if they have already been oom - * killed to prevent needlessly killing additional tasks. - */ - rcu_read_lock(); - task_memcg = mem_cgroup_from_task(task); - css_get(&task_memcg->css); - rcu_read_unlock(); - } - ret = mem_cgroup_is_descendant(task_memcg, memcg); - css_put(&task_memcg->css); - return ret; -} +EXPORT_SYMBOL_GPL(mem_cgroup_update_lru_size); /** * mem_cgroup_margin - calculate chargeable space of a memory cgroup @@ -1245,7 +1467,7 @@ if (do_memsw_account()) { count = page_counter_read(&memcg->memsw); limit = READ_ONCE(memcg->memsw.max); - if (count <= limit) + if (count < limit) margin = min(margin, limit - count); else margin = 0; @@ -1299,85 +1521,199 @@ return false; } -static const unsigned int memcg1_stats[] = { - MEMCG_CACHE, - MEMCG_RSS, - MEMCG_RSS_HUGE, - NR_SHMEM, - NR_FILE_MAPPED, - NR_FILE_DIRTY, - NR_WRITEBACK, - MEMCG_SWAP, +struct memory_stat { + const char *name; + unsigned int ratio; + unsigned int idx; }; -static const char *const memcg1_stat_names[] = { - "cache", - "rss", - "rss_huge", - "shmem", - "mapped_file", - "dirty", - "writeback", - "swap", +static struct memory_stat memory_stats[] = { + { "anon", PAGE_SIZE, NR_ANON_MAPPED }, + { "file", PAGE_SIZE, NR_FILE_PAGES }, + { "kernel_stack", 1024, NR_KERNEL_STACK_KB }, + { "percpu", 1, MEMCG_PERCPU_B }, + { "sock", PAGE_SIZE, MEMCG_SOCK }, + { "shmem", PAGE_SIZE, NR_SHMEM }, + { "file_mapped", PAGE_SIZE, NR_FILE_MAPPED }, + { "file_dirty", PAGE_SIZE, NR_FILE_DIRTY }, + { "file_writeback", PAGE_SIZE, NR_WRITEBACK }, +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + /* + * The ratio will be initialized in memory_stats_init(). Because + * on some architectures, the macro of HPAGE_PMD_SIZE is not + * constant(e.g. powerpc). + */ + { "anon_thp", 0, NR_ANON_THPS }, +#endif + { "inactive_anon", PAGE_SIZE, NR_INACTIVE_ANON }, + { "active_anon", PAGE_SIZE, NR_ACTIVE_ANON }, + { "inactive_file", PAGE_SIZE, NR_INACTIVE_FILE }, + { "active_file", PAGE_SIZE, NR_ACTIVE_FILE }, + { "unevictable", PAGE_SIZE, NR_UNEVICTABLE }, + + /* + * Note: The slab_reclaimable and slab_unreclaimable must be + * together and slab_reclaimable must be in front. + */ + { "slab_reclaimable", 1, NR_SLAB_RECLAIMABLE_B }, + { "slab_unreclaimable", 1, NR_SLAB_UNRECLAIMABLE_B }, + + /* The memory events */ + { "workingset_refault_anon", 1, WORKINGSET_REFAULT_ANON }, + { "workingset_refault_file", 1, WORKINGSET_REFAULT_FILE }, + { "workingset_activate_anon", 1, WORKINGSET_ACTIVATE_ANON }, + { "workingset_activate_file", 1, WORKINGSET_ACTIVATE_FILE }, + { "workingset_restore_anon", 1, WORKINGSET_RESTORE_ANON }, + { "workingset_restore_file", 1, WORKINGSET_RESTORE_FILE }, + { "workingset_nodereclaim", 1, WORKINGSET_NODERECLAIM }, }; + +static int __init memory_stats_init(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + if (memory_stats[i].idx == NR_ANON_THPS) + memory_stats[i].ratio = HPAGE_PMD_SIZE; +#endif + VM_BUG_ON(!memory_stats[i].ratio); + VM_BUG_ON(memory_stats[i].idx >= MEMCG_NR_STAT); + } + + return 0; +} +pure_initcall(memory_stats_init); + +static char *memory_stat_format(struct mem_cgroup *memcg) +{ + struct seq_buf s; + int i; + + seq_buf_init(&s, kmalloc(PAGE_SIZE, GFP_KERNEL), PAGE_SIZE); + if (!s.buffer) + return NULL; + + /* + * Provide statistics on the state of the memory subsystem as + * well as cumulative event counters that show past behavior. + * + * This list is ordered following a combination of these gradients: + * 1) generic big picture -> specifics and details + * 2) reflecting userspace activity -> reflecting kernel heuristics + * + * Current memory state: + */ + + for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { + u64 size; + + size = memcg_page_state(memcg, memory_stats[i].idx); + size *= memory_stats[i].ratio; + seq_buf_printf(&s, "%s %llu\n", memory_stats[i].name, size); + + if (unlikely(memory_stats[i].idx == NR_SLAB_UNRECLAIMABLE_B)) { + size = memcg_page_state(memcg, NR_SLAB_RECLAIMABLE_B) + + memcg_page_state(memcg, NR_SLAB_UNRECLAIMABLE_B); + seq_buf_printf(&s, "slab %llu\n", size); + } + } + + /* Accumulated memory events */ + + seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGFAULT), + memcg_events(memcg, PGFAULT)); + seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGMAJFAULT), + memcg_events(memcg, PGMAJFAULT)); + seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGREFILL), + memcg_events(memcg, PGREFILL)); + seq_buf_printf(&s, "pgscan %lu\n", + memcg_events(memcg, PGSCAN_KSWAPD) + + memcg_events(memcg, PGSCAN_DIRECT)); + seq_buf_printf(&s, "pgsteal %lu\n", + memcg_events(memcg, PGSTEAL_KSWAPD) + + memcg_events(memcg, PGSTEAL_DIRECT)); + seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGACTIVATE), + memcg_events(memcg, PGACTIVATE)); + seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGDEACTIVATE), + memcg_events(memcg, PGDEACTIVATE)); + seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGLAZYFREE), + memcg_events(memcg, PGLAZYFREE)); + seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGLAZYFREED), + memcg_events(memcg, PGLAZYFREED)); + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + seq_buf_printf(&s, "%s %lu\n", vm_event_name(THP_FAULT_ALLOC), + memcg_events(memcg, THP_FAULT_ALLOC)); + seq_buf_printf(&s, "%s %lu\n", vm_event_name(THP_COLLAPSE_ALLOC), + memcg_events(memcg, THP_COLLAPSE_ALLOC)); +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + + /* The above should easily fit into one page */ + WARN_ON_ONCE(seq_buf_has_overflowed(&s)); + + return s.buffer; +} #define K(x) ((x) << (PAGE_SHIFT-10)) /** - * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller. + * mem_cgroup_print_oom_context: Print OOM information relevant to + * memory controller. * @memcg: The memory cgroup that went over limit * @p: Task that is going to be killed * * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is * enabled */ -void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) +void mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct *p) { - struct mem_cgroup *iter; - unsigned int i; - rcu_read_lock(); + if (memcg) { + pr_cont(",oom_memcg="); + pr_cont_cgroup_path(memcg->css.cgroup); + } else + pr_cont(",global_oom"); if (p) { - pr_info("Task in "); + pr_cont(",task_memcg="); pr_cont_cgroup_path(task_cgroup(p, memory_cgrp_id)); - pr_cont(" killed as a result of limit of "); - } else { - pr_info("Memory limit reached of cgroup "); } - - pr_cont_cgroup_path(memcg->css.cgroup); - pr_cont("\n"); - rcu_read_unlock(); +} + +/** + * mem_cgroup_print_oom_meminfo: Print OOM memory information relevant to + * memory controller. + * @memcg: The memory cgroup that went over limit + */ +void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg) +{ + char *buf; pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n", K((u64)page_counter_read(&memcg->memory)), - K((u64)memcg->memory.max), memcg->memory.failcnt); - pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n", - K((u64)page_counter_read(&memcg->memsw)), - K((u64)memcg->memsw.max), memcg->memsw.failcnt); - pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n", - K((u64)page_counter_read(&memcg->kmem)), - K((u64)memcg->kmem.max), memcg->kmem.failcnt); - - for_each_mem_cgroup_tree(iter, memcg) { - pr_info("Memory cgroup stats for "); - pr_cont_cgroup_path(iter->css.cgroup); - pr_cont(":"); - - for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { - if (memcg1_stats[i] == MEMCG_SWAP && !do_swap_account) - continue; - pr_cont(" %s:%luKB", memcg1_stat_names[i], - K(memcg_page_state(iter, memcg1_stats[i]))); - } - - for (i = 0; i < NR_LRU_LISTS; i++) - pr_cont(" %s:%luKB", mem_cgroup_lru_names[i], - K(mem_cgroup_nr_lru_pages(iter, BIT(i)))); - - pr_cont("\n"); + K((u64)READ_ONCE(memcg->memory.max)), memcg->memory.failcnt); + if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) + pr_info("swap: usage %llukB, limit %llukB, failcnt %lu\n", + K((u64)page_counter_read(&memcg->swap)), + K((u64)READ_ONCE(memcg->swap.max)), memcg->swap.failcnt); + else { + pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n", + K((u64)page_counter_read(&memcg->memsw)), + K((u64)memcg->memsw.max), memcg->memsw.failcnt); + pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n", + K((u64)page_counter_read(&memcg->kmem)), + K((u64)memcg->kmem.max), memcg->kmem.failcnt); } + + pr_info("Memory cgroup stats for "); + pr_cont_cgroup_path(memcg->css.cgroup); + pr_cont(":"); + buf = memory_stat_format(memcg); + if (!buf) + return; + pr_info("%s", buf); + kfree(buf); } /* @@ -1385,19 +1721,26 @@ */ unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg) { - unsigned long max; + unsigned long max = READ_ONCE(memcg->memory.max); - max = memcg->memory.max; - if (mem_cgroup_swappiness(memcg)) { - unsigned long memsw_max; - unsigned long swap_max; + if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) { + if (mem_cgroup_swappiness(memcg)) + max += min(READ_ONCE(memcg->swap.max), + (unsigned long)total_swap_pages); + } else { /* v1 */ + if (mem_cgroup_swappiness(memcg)) { + /* Calculate swap excess capacity from memsw limit */ + unsigned long swap = READ_ONCE(memcg->memsw.max) - max; - memsw_max = memcg->memsw.max; - swap_max = memcg->swap.max; - swap_max = min(swap_max, (unsigned long)total_swap_pages); - max = min(max + swap_max, memsw_max); + max += min(swap, (unsigned long)total_swap_pages); + } } return max; +} + +unsigned long mem_cgroup_size(struct mem_cgroup *memcg) +{ + return page_counter_read(&memcg->memory); } static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, @@ -1410,112 +1753,24 @@ .gfp_mask = gfp_mask, .order = order, }; - bool ret; + bool ret = true; if (mutex_lock_killable(&oom_lock)) return true; + + if (mem_cgroup_margin(memcg) >= (1 << order)) + goto unlock; + /* * A few threads which were not waiting at mutex_lock_killable() can * fail to bail out. Therefore, check again after holding oom_lock. */ - ret = should_force_charge() || out_of_memory(&oc); + ret = task_is_dying() || out_of_memory(&oc); + +unlock: mutex_unlock(&oom_lock); return ret; } - -#if MAX_NUMNODES > 1 - -/** - * test_mem_cgroup_node_reclaimable - * @memcg: the target memcg - * @nid: the node ID to be checked. - * @noswap : specify true here if the user wants flle only information. - * - * This function returns whether the specified memcg contains any - * reclaimable pages on a node. Returns true if there are any reclaimable - * pages in the node. - */ -static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg, - int nid, bool noswap) -{ - if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE)) - return true; - if (noswap || !total_swap_pages) - return false; - if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON)) - return true; - return false; - -} - -/* - * Always updating the nodemask is not very good - even if we have an empty - * list or the wrong list here, we can start from some node and traverse all - * nodes based on the zonelist. So update the list loosely once per 10 secs. - * - */ -static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg) -{ - int nid; - /* - * numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET - * pagein/pageout changes since the last update. - */ - if (!atomic_read(&memcg->numainfo_events)) - return; - if (atomic_inc_return(&memcg->numainfo_updating) > 1) - return; - - /* make a nodemask where this memcg uses memory from */ - memcg->scan_nodes = node_states[N_MEMORY]; - - for_each_node_mask(nid, node_states[N_MEMORY]) { - - if (!test_mem_cgroup_node_reclaimable(memcg, nid, false)) - node_clear(nid, memcg->scan_nodes); - } - - atomic_set(&memcg->numainfo_events, 0); - atomic_set(&memcg->numainfo_updating, 0); -} - -/* - * Selecting a node where we start reclaim from. Because what we need is just - * reducing usage counter, start from anywhere is O,K. Considering - * memory reclaim from current node, there are pros. and cons. - * - * Freeing memory from current node means freeing memory from a node which - * we'll use or we've used. So, it may make LRU bad. And if several threads - * hit limits, it will see a contention on a node. But freeing from remote - * node means more costs for memory reclaim because of memory latency. - * - * Now, we use round-robin. Better algorithm is welcomed. - */ -int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) -{ - int node; - - mem_cgroup_may_update_nodemask(memcg); - node = memcg->last_scanned_node; - - node = next_node_in(node, memcg->scan_nodes); - /* - * mem_cgroup_may_update_nodemask might have seen no reclaimmable pages - * last time it really checked all the LRUs due to rate limiting. - * Fallback to the current node in that case for simplicity. - */ - if (unlikely(node == MAX_NUMNODES)) - node = numa_node_id(); - - memcg->last_scanned_node = node; - return node; -} -#else -int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) -{ - return 0; -} -#endif static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, pg_data_t *pgdat, @@ -1529,7 +1784,6 @@ unsigned long nr_scanned; struct mem_cgroup_reclaim_cookie reclaim = { .pgdat = pgdat, - .priority = 0, }; excess = soft_limit_excess(root_memcg); @@ -1624,7 +1878,7 @@ struct mem_cgroup *iter; spin_lock(&memcg_oom_lock); - mutex_release(&memcg_oom_lock_dep_map, 1, _RET_IP_); + mutex_release(&memcg_oom_lock_dep_map, _RET_IP_); for_each_mem_cgroup_tree(iter, memcg) iter->oom_lock = false; spin_unlock(&memcg_oom_lock); @@ -1645,8 +1899,8 @@ struct mem_cgroup *iter; /* - * When a new child is created while the hierarchy is under oom, - * mem_cgroup_oom_lock() may not be called. Watch for underflow. + * Be careful about under_oom underflows becase a child memcg + * could have been added after mem_cgroup_mark_under_oom. */ spin_lock(&memcg_oom_lock); for_each_mem_cgroup_tree(iter, memcg) @@ -1706,6 +1960,8 @@ if (order > PAGE_ALLOC_COSTLY_ORDER) return OOM_SKIPPED; + + memcg_memory_event(memcg, MEMCG_OOM); /* * We are in the middle of the charge context here, so we @@ -1854,6 +2110,14 @@ goto out; /* + * If the victim task has been asynchronously moved to a different + * memory cgroup, we might end up killing tasks outside oom_domain. + * In this case it's better to ignore memory.group.oom. + */ + if (unlikely(!mem_cgroup_is_descendant(memcg, oom_domain))) + goto out; + + /* * Traverse the memory cgroup hierarchy from the victim task's * cgroup up to the OOMing cgroup (or root) to find the * highest-level memory cgroup with oom.group set. @@ -1894,6 +2158,7 @@ */ struct mem_cgroup *lock_page_memcg(struct page *page) { + struct page *head = compound_head(page); /* rmap on tail pages */ struct mem_cgroup *memcg; unsigned long flags; @@ -1913,7 +2178,7 @@ if (mem_cgroup_disabled()) return NULL; again: - memcg = page->mem_cgroup; + memcg = head->mem_cgroup; if (unlikely(!memcg)) return NULL; @@ -1921,7 +2186,7 @@ return memcg; spin_lock_irqsave(&memcg->move_lock, flags); - if (memcg != page->mem_cgroup) { + if (memcg != head->mem_cgroup) { spin_unlock_irqrestore(&memcg->move_lock, flags); goto again; } @@ -1964,19 +2229,43 @@ */ void unlock_page_memcg(struct page *page) { - __unlock_page_memcg(page->mem_cgroup); + struct page *head = compound_head(page); + + __unlock_page_memcg(head->mem_cgroup); } EXPORT_SYMBOL(unlock_page_memcg); struct memcg_stock_pcp { struct mem_cgroup *cached; /* this never be root cgroup */ unsigned int nr_pages; + +#ifdef CONFIG_MEMCG_KMEM + struct obj_cgroup *cached_objcg; + unsigned int nr_bytes; +#endif + struct work_struct work; unsigned long flags; #define FLUSHING_CACHED_CHARGE 0 }; static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); static DEFINE_MUTEX(percpu_charge_mutex); + +#ifdef CONFIG_MEMCG_KMEM +static void drain_obj_stock(struct memcg_stock_pcp *stock); +static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, + struct mem_cgroup *root_memcg); + +#else +static inline void drain_obj_stock(struct memcg_stock_pcp *stock) +{ +} +static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, + struct mem_cgroup *root_memcg) +{ + return false; +} +#endif /** * consume_stock: Try to consume stocked charge on this cpu. @@ -2018,13 +2307,17 @@ { struct mem_cgroup *old = stock->cached; + if (!old) + return; + if (stock->nr_pages) { page_counter_uncharge(&old->memory, stock->nr_pages); if (do_memsw_account()) page_counter_uncharge(&old->memsw, stock->nr_pages); - css_put_many(&old->css, stock->nr_pages); stock->nr_pages = 0; } + + css_put(&old->css); stock->cached = NULL; } @@ -2040,6 +2333,7 @@ local_irq_save(flags); stock = this_cpu_ptr(&memcg_stock); + drain_obj_stock(stock); drain_stock(stock); clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); @@ -2060,6 +2354,7 @@ stock = this_cpu_ptr(&memcg_stock); if (stock->cached != memcg) { /* reset if necessary */ drain_stock(stock); + css_get(&memcg->css); stock->cached = memcg; } stock->nr_pages += nr_pages; @@ -2087,34 +2382,37 @@ * as well as workers from this path always operate on the local * per-cpu data. CPU up doesn't touch memcg_stock at all. */ - curcpu = get_cpu_light(); + curcpu = get_cpu(); for_each_online_cpu(cpu) { struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); struct mem_cgroup *memcg; + bool flush = false; + rcu_read_lock(); memcg = stock->cached; - if (!memcg || !stock->nr_pages || !css_tryget(&memcg->css)) - continue; - if (!mem_cgroup_is_descendant(memcg, root_memcg)) { - css_put(&memcg->css); - continue; - } - if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { + if (memcg && stock->nr_pages && + mem_cgroup_is_descendant(memcg, root_memcg)) + flush = true; + if (obj_stock_flush_required(stock, root_memcg)) + flush = true; + rcu_read_unlock(); + + if (flush && + !test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { if (cpu == curcpu) drain_local_stock(&stock->work); else schedule_work_on(cpu, &stock->work); } - css_put(&memcg->css); } - put_cpu_light(); + put_cpu(); mutex_unlock(&percpu_charge_mutex); } static int memcg_hotplug_cpu_dead(unsigned int cpu) { struct memcg_stock_pcp *stock; - struct mem_cgroup *memcg; + struct mem_cgroup *memcg, *mi; stock = &per_cpu(memcg_stock, cpu); drain_stock(stock); @@ -2126,9 +2424,10 @@ int nid; long x; - x = this_cpu_xchg(memcg->stat_cpu->count[i], 0); + x = this_cpu_xchg(memcg->vmstats_percpu->stat[i], 0); if (x) - atomic_long_add(x, &memcg->stat[i]); + for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) + atomic_long_add(x, &memcg->vmstats[i]); if (i >= NR_VM_NODE_STAT_ITEMS) continue; @@ -2139,32 +2438,48 @@ pn = mem_cgroup_nodeinfo(memcg, nid); x = this_cpu_xchg(pn->lruvec_stat_cpu->count[i], 0); if (x) - atomic_long_add(x, &pn->lruvec_stat[i]); + do { + atomic_long_add(x, &pn->lruvec_stat[i]); + } while ((pn = parent_nodeinfo(pn, nid))); } } for (i = 0; i < NR_VM_EVENT_ITEMS; i++) { long x; - x = this_cpu_xchg(memcg->stat_cpu->events[i], 0); + x = this_cpu_xchg(memcg->vmstats_percpu->events[i], 0); if (x) - atomic_long_add(x, &memcg->events[i]); + for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) + atomic_long_add(x, &memcg->vmevents[i]); } } return 0; } -static void reclaim_high(struct mem_cgroup *memcg, - unsigned int nr_pages, - gfp_t gfp_mask) +static unsigned long reclaim_high(struct mem_cgroup *memcg, + unsigned int nr_pages, + gfp_t gfp_mask) { + unsigned long nr_reclaimed = 0; + do { - if (page_counter_read(&memcg->memory) <= memcg->high) + unsigned long pflags; + + if (page_counter_read(&memcg->memory) <= + READ_ONCE(memcg->memory.high)) continue; + memcg_memory_event(memcg, MEMCG_HIGH); - try_to_free_mem_cgroup_pages(memcg, nr_pages, gfp_mask, true); - } while ((memcg = parent_mem_cgroup(memcg))); + + psi_memstall_enter(&pflags); + nr_reclaimed += try_to_free_mem_cgroup_pages(memcg, nr_pages, + gfp_mask, true); + psi_memstall_leave(&pflags); + } while ((memcg = parent_mem_cgroup(memcg)) && + !mem_cgroup_is_root(memcg)); + + return nr_reclaimed; } static void high_work_func(struct work_struct *work) @@ -2176,35 +2491,238 @@ } /* + * Clamp the maximum sleep time per allocation batch to 2 seconds. This is + * enough to still cause a significant slowdown in most cases, while still + * allowing diagnostics and tracing to proceed without becoming stuck. + */ +#define MEMCG_MAX_HIGH_DELAY_JIFFIES (2UL*HZ) + +/* + * When calculating the delay, we use these either side of the exponentiation to + * maintain precision and scale to a reasonable number of jiffies (see the table + * below. + * + * - MEMCG_DELAY_PRECISION_SHIFT: Extra precision bits while translating the + * overage ratio to a delay. + * - MEMCG_DELAY_SCALING_SHIFT: The number of bits to scale down the + * proposed penalty in order to reduce to a reasonable number of jiffies, and + * to produce a reasonable delay curve. + * + * MEMCG_DELAY_SCALING_SHIFT just happens to be a number that produces a + * reasonable delay curve compared to precision-adjusted overage, not + * penalising heavily at first, but still making sure that growth beyond the + * limit penalises misbehaviour cgroups by slowing them down exponentially. For + * example, with a high of 100 megabytes: + * + * +-------+------------------------+ + * | usage | time to allocate in ms | + * +-------+------------------------+ + * | 100M | 0 | + * | 101M | 6 | + * | 102M | 25 | + * | 103M | 57 | + * | 104M | 102 | + * | 105M | 159 | + * | 106M | 230 | + * | 107M | 313 | + * | 108M | 409 | + * | 109M | 518 | + * | 110M | 639 | + * | 111M | 774 | + * | 112M | 921 | + * | 113M | 1081 | + * | 114M | 1254 | + * | 115M | 1439 | + * | 116M | 1638 | + * | 117M | 1849 | + * | 118M | 2000 | + * | 119M | 2000 | + * | 120M | 2000 | + * +-------+------------------------+ + */ + #define MEMCG_DELAY_PRECISION_SHIFT 20 + #define MEMCG_DELAY_SCALING_SHIFT 14 + +static u64 calculate_overage(unsigned long usage, unsigned long high) +{ + u64 overage; + + if (usage <= high) + return 0; + + /* + * Prevent division by 0 in overage calculation by acting as if + * it was a threshold of 1 page + */ + high = max(high, 1UL); + + overage = usage - high; + overage <<= MEMCG_DELAY_PRECISION_SHIFT; + return div64_u64(overage, high); +} + +static u64 mem_find_max_overage(struct mem_cgroup *memcg) +{ + u64 overage, max_overage = 0; + + do { + overage = calculate_overage(page_counter_read(&memcg->memory), + READ_ONCE(memcg->memory.high)); + max_overage = max(overage, max_overage); + } while ((memcg = parent_mem_cgroup(memcg)) && + !mem_cgroup_is_root(memcg)); + + return max_overage; +} + +static u64 swap_find_max_overage(struct mem_cgroup *memcg) +{ + u64 overage, max_overage = 0; + + do { + overage = calculate_overage(page_counter_read(&memcg->swap), + READ_ONCE(memcg->swap.high)); + if (overage) + memcg_memory_event(memcg, MEMCG_SWAP_HIGH); + max_overage = max(overage, max_overage); + } while ((memcg = parent_mem_cgroup(memcg)) && + !mem_cgroup_is_root(memcg)); + + return max_overage; +} + +/* + * Get the number of jiffies that we should penalise a mischievous cgroup which + * is exceeding its memory.high by checking both it and its ancestors. + */ +static unsigned long calculate_high_delay(struct mem_cgroup *memcg, + unsigned int nr_pages, + u64 max_overage) +{ + unsigned long penalty_jiffies; + + if (!max_overage) + return 0; + + /* + * We use overage compared to memory.high to calculate the number of + * jiffies to sleep (penalty_jiffies). Ideally this value should be + * fairly lenient on small overages, and increasingly harsh when the + * memcg in question makes it clear that it has no intention of stopping + * its crazy behaviour, so we exponentially increase the delay based on + * overage amount. + */ + penalty_jiffies = max_overage * max_overage * HZ; + penalty_jiffies >>= MEMCG_DELAY_PRECISION_SHIFT; + penalty_jiffies >>= MEMCG_DELAY_SCALING_SHIFT; + + /* + * Factor in the task's own contribution to the overage, such that four + * N-sized allocations are throttled approximately the same as one + * 4N-sized allocation. + * + * MEMCG_CHARGE_BATCH pages is nominal, so work out how much smaller or + * larger the current charge patch is than that. + */ + return penalty_jiffies * nr_pages / MEMCG_CHARGE_BATCH; +} + +/* * Scheduled by try_charge() to be executed from the userland return path * and reclaims memory over the high limit. */ void mem_cgroup_handle_over_high(void) { + unsigned long penalty_jiffies; + unsigned long pflags; + unsigned long nr_reclaimed; unsigned int nr_pages = current->memcg_nr_pages_over_high; + int nr_retries = MAX_RECLAIM_RETRIES; struct mem_cgroup *memcg; + bool in_retry = false; if (likely(!nr_pages)) return; memcg = get_mem_cgroup_from_mm(current->mm); - reclaim_high(memcg, nr_pages, GFP_KERNEL); - css_put(&memcg->css); current->memcg_nr_pages_over_high = 0; + +retry_reclaim: + /* + * The allocating task should reclaim at least the batch size, but for + * subsequent retries we only want to do what's necessary to prevent oom + * or breaching resource isolation. + * + * This is distinct from memory.max or page allocator behaviour because + * memory.high is currently batched, whereas memory.max and the page + * allocator run every time an allocation is made. + */ + nr_reclaimed = reclaim_high(memcg, + in_retry ? SWAP_CLUSTER_MAX : nr_pages, + GFP_KERNEL); + + /* + * memory.high is breached and reclaim is unable to keep up. Throttle + * allocators proactively to slow down excessive growth. + */ + penalty_jiffies = calculate_high_delay(memcg, nr_pages, + mem_find_max_overage(memcg)); + + penalty_jiffies += calculate_high_delay(memcg, nr_pages, + swap_find_max_overage(memcg)); + + /* + * Clamp the max delay per usermode return so as to still keep the + * application moving forwards and also permit diagnostics, albeit + * extremely slowly. + */ + penalty_jiffies = min(penalty_jiffies, MEMCG_MAX_HIGH_DELAY_JIFFIES); + + /* + * Don't sleep if the amount of jiffies this memcg owes us is so low + * that it's not even worth doing, in an attempt to be nice to those who + * go only a small amount over their memory.high value and maybe haven't + * been aggressively reclaimed enough yet. + */ + if (penalty_jiffies <= HZ / 100) + goto out; + + /* + * If reclaim is making forward progress but we're still over + * memory.high, we want to encourage that rather than doing allocator + * throttling. + */ + if (nr_reclaimed || nr_retries--) { + in_retry = true; + goto retry_reclaim; + } + + /* + * If we exit early, we're guaranteed to die (since + * schedule_timeout_killable sets TASK_KILLABLE). This means we don't + * need to account for any ill-begotten jiffies to pay them off later. + */ + psi_memstall_enter(&pflags); + schedule_timeout_killable(penalty_jiffies); + psi_memstall_leave(&pflags); + +out: + css_put(&memcg->css); } static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, unsigned int nr_pages) { unsigned int batch = max(MEMCG_CHARGE_BATCH, nr_pages); - int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; + int nr_retries = MAX_RECLAIM_RETRIES; struct mem_cgroup *mem_over_limit; struct page_counter *counter; + enum oom_status oom_status; unsigned long nr_reclaimed; + bool passed_oom = false; bool may_swap = true; bool drained = false; - bool oomed = false; - enum oom_status oom_status; + unsigned long pflags; if (mem_cgroup_is_root(memcg)) return 0; @@ -2239,15 +2757,6 @@ goto force; /* - * Unlike in global OOM situations, memcg is not in a physical - * memory shortage. Allow dying and OOM-killed tasks to - * bypass the last charges so that they can exit quickly and - * free their memory. - */ - if (unlikely(should_force_charge())) - goto force; - - /* * Prevent unbounded recursion when reclaim operations need to * allocate memory. This might exceed the limits temporarily, * but we prefer facilitating memory reclaim and getting back @@ -2264,8 +2773,10 @@ memcg_memory_event(mem_over_limit, MEMCG_MAX); + psi_memstall_enter(&pflags); nr_reclaimed = try_to_free_mem_cgroup_pages(mem_over_limit, nr_pages, gfp_mask, may_swap); + psi_memstall_leave(&pflags); if (mem_cgroup_margin(mem_over_limit) >= nr_pages) goto retry; @@ -2299,16 +2810,15 @@ if (nr_retries--) goto retry; - if (gfp_mask & __GFP_RETRY_MAYFAIL && oomed) + if (gfp_mask & __GFP_RETRY_MAYFAIL) goto nomem; if (gfp_mask & __GFP_NOFAIL) goto force; - if (fatal_signal_pending(current)) - goto force; - - memcg_memory_event(mem_over_limit, MEMCG_OOM); + /* Avoid endless loop for tasks bypassed by the oom killer */ + if (passed_oom && task_is_dying()) + goto nomem; /* * keep retrying as long as the memcg oom killer is able to make @@ -2317,15 +2827,10 @@ */ oom_status = mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(nr_pages * PAGE_SIZE)); - switch (oom_status) { - case OOM_SUCCESS: - nr_retries = MEM_CGROUP_RECLAIM_RETRIES; - oomed = true; + if (oom_status == OOM_SUCCESS) { + passed_oom = true; + nr_retries = MAX_RECLAIM_RETRIES; goto retry; - case OOM_FAILED: - goto force; - default: - goto nomem; } nomem: if (!(gfp_mask & __GFP_NOFAIL)) @@ -2339,12 +2844,10 @@ page_counter_charge(&memcg->memory, nr_pages); if (do_memsw_account()) page_counter_charge(&memcg->memsw, nr_pages); - css_get_many(&memcg->css, nr_pages); return 0; done_restock: - css_get_many(&memcg->css, batch); if (batch > nr_pages) refill_stock(memcg, batch - nr_pages); @@ -2358,12 +2861,32 @@ * reclaim, the cost of mismatch is negligible. */ do { - if (page_counter_read(&memcg->memory) > memcg->high) { - /* Don't bother a random interrupted task */ - if (in_interrupt()) { + bool mem_high, swap_high; + + mem_high = page_counter_read(&memcg->memory) > + READ_ONCE(memcg->memory.high); + swap_high = page_counter_read(&memcg->swap) > + READ_ONCE(memcg->swap.high); + + /* Don't bother a random interrupted task */ + if (in_interrupt()) { + if (mem_high) { schedule_work(&memcg->high_work); break; } + continue; + } + + if (mem_high || swap_high) { + /* + * The allocating tasks in this cgroup will need to do + * reclaim or be throttled to prevent further growth + * of the memory or swap footprints. + * + * Target some best-effort fairness between the tasks, + * and distribute reclaim work and delay penalties + * based on how much each task is actually allocating. + */ current->memcg_nr_pages_over_high += batch; set_notify_resume(current); break; @@ -2373,6 +2896,7 @@ return 0; } +#if defined(CONFIG_MEMCG_KMEM) || defined(CONFIG_MMU) static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) { if (mem_cgroup_is_root(memcg)) @@ -2381,76 +2905,124 @@ page_counter_uncharge(&memcg->memory, nr_pages); if (do_memsw_account()) page_counter_uncharge(&memcg->memsw, nr_pages); - - css_put_many(&memcg->css, nr_pages); } +#endif -static void lock_page_lru(struct page *page, int *isolated) +static void commit_charge(struct page *page, struct mem_cgroup *memcg) { - struct zone *zone = page_zone(page); - - spin_lock_irq(zone_lru_lock(zone)); - if (PageLRU(page)) { - struct lruvec *lruvec; - - lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat); - ClearPageLRU(page); - del_page_from_lru_list(page, lruvec, page_lru(page)); - *isolated = 1; - } else - *isolated = 0; -} - -static void unlock_page_lru(struct page *page, int isolated) -{ - struct zone *zone = page_zone(page); - - if (isolated) { - struct lruvec *lruvec; - - lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat); - VM_BUG_ON_PAGE(PageLRU(page), page); - SetPageLRU(page); - add_page_to_lru_list(page, lruvec, page_lru(page)); - } - spin_unlock_irq(zone_lru_lock(zone)); -} - -static void commit_charge(struct page *page, struct mem_cgroup *memcg, - bool lrucare) -{ - int isolated; - VM_BUG_ON_PAGE(page->mem_cgroup, page); - /* - * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page - * may already be on some other mem_cgroup's LRU. Take care of it. - */ - if (lrucare) - lock_page_lru(page, &isolated); - - /* - * Nobody should be changing or seriously looking at - * page->mem_cgroup at this point: + * Any of the following ensures page->mem_cgroup stability: * - * - the page is uncharged - * - * - the page is off-LRU - * - * - an anonymous fault has exclusive page access, except for - * a locked page table - * - * - a page cache insertion, a swapin fault, or a migration - * have the page locked + * - the page lock + * - LRU isolation + * - lock_page_memcg() + * - exclusive reference */ page->mem_cgroup = memcg; - - if (lrucare) - unlock_page_lru(page, isolated); } #ifdef CONFIG_MEMCG_KMEM +/* + * The allocated objcg pointers array is not accounted directly. + * Moreover, it should not come from DMA buffer and is not readily + * reclaimable. So those GFP bits should be masked off. + */ +#define OBJCGS_CLEAR_MASK (__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT) + +int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s, + gfp_t gfp) +{ + unsigned int objects = objs_per_slab_page(s, page); + void *vec; + + gfp &= ~OBJCGS_CLEAR_MASK; + vec = kcalloc_node(objects, sizeof(struct obj_cgroup *), gfp, + page_to_nid(page)); + if (!vec) + return -ENOMEM; + + if (cmpxchg(&page->obj_cgroups, NULL, + (struct obj_cgroup **) ((unsigned long)vec | 0x1UL))) + kfree(vec); + else + kmemleak_not_leak(vec); + + return 0; +} + +/* + * Returns a pointer to the memory cgroup to which the kernel object is charged. + * + * The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(), + * cgroup_mutex, etc. + */ +struct mem_cgroup *mem_cgroup_from_obj(void *p) +{ + struct page *page; + + if (mem_cgroup_disabled()) + return NULL; + + page = virt_to_head_page(p); + + /* + * If page->mem_cgroup is set, it's either a simple mem_cgroup pointer + * or a pointer to obj_cgroup vector. In the latter case the lowest + * bit of the pointer is set. + * The page->mem_cgroup pointer can be asynchronously changed + * from NULL to (obj_cgroup_vec | 0x1UL), but can't be changed + * from a valid memcg pointer to objcg vector or back. + */ + if (!page->mem_cgroup) + return NULL; + + /* + * Slab objects are accounted individually, not per-page. + * Memcg membership data for each individual object is saved in + * the page->obj_cgroups. + */ + if (page_has_obj_cgroups(page)) { + struct obj_cgroup *objcg; + unsigned int off; + + off = obj_to_index(page->slab_cache, page, p); + objcg = page_obj_cgroups(page)[off]; + if (objcg) + return obj_cgroup_memcg(objcg); + + return NULL; + } + + /* All other pages use page->mem_cgroup */ + return page->mem_cgroup; +} + +__always_inline struct obj_cgroup *get_obj_cgroup_from_current(void) +{ + struct obj_cgroup *objcg = NULL; + struct mem_cgroup *memcg; + + if (memcg_kmem_bypass()) + return NULL; + + rcu_read_lock(); + if (unlikely(active_memcg())) + memcg = active_memcg(); + else + memcg = mem_cgroup_from_task(current); + + for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) { + objcg = rcu_dereference(memcg->objcg); + if (objcg && obj_cgroup_tryget(objcg)) + break; + objcg = NULL; + } + rcu_read_unlock(); + + return objcg; +} + static int memcg_alloc_cache_id(void) { int id, size; @@ -2476,9 +3048,7 @@ else if (size > MEMCG_CACHES_MAX_SIZE) size = MEMCG_CACHES_MAX_SIZE; - err = memcg_update_all_caches(size); - if (!err) - err = memcg_update_all_list_lrus(size); + err = memcg_update_all_list_lrus(size); if (!err) memcg_nr_cache_ids = size; @@ -2496,152 +3066,17 @@ ida_simple_remove(&memcg_cache_ida, id); } -struct memcg_kmem_cache_create_work { - struct mem_cgroup *memcg; - struct kmem_cache *cachep; - struct work_struct work; -}; - -static void memcg_kmem_cache_create_func(struct work_struct *w) -{ - struct memcg_kmem_cache_create_work *cw = - container_of(w, struct memcg_kmem_cache_create_work, work); - struct mem_cgroup *memcg = cw->memcg; - struct kmem_cache *cachep = cw->cachep; - - memcg_create_kmem_cache(memcg, cachep); - - css_put(&memcg->css); - kfree(cw); -} - -/* - * Enqueue the creation of a per-memcg kmem_cache. - */ -static void __memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg, - struct kmem_cache *cachep) -{ - struct memcg_kmem_cache_create_work *cw; - - cw = kmalloc(sizeof(*cw), GFP_NOWAIT | __GFP_NOWARN); - if (!cw) - return; - - css_get(&memcg->css); - - cw->memcg = memcg; - cw->cachep = cachep; - INIT_WORK(&cw->work, memcg_kmem_cache_create_func); - - queue_work(memcg_kmem_cache_wq, &cw->work); -} - -static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg, - struct kmem_cache *cachep) -{ - /* - * We need to stop accounting when we kmalloc, because if the - * corresponding kmalloc cache is not yet created, the first allocation - * in __memcg_schedule_kmem_cache_create will recurse. - * - * However, it is better to enclose the whole function. Depending on - * the debugging options enabled, INIT_WORK(), for instance, can - * trigger an allocation. This too, will make us recurse. Because at - * this point we can't allow ourselves back into memcg_kmem_get_cache, - * the safest choice is to do it like this, wrapping the whole function. - */ - current->memcg_kmem_skip_account = 1; - __memcg_schedule_kmem_cache_create(memcg, cachep); - current->memcg_kmem_skip_account = 0; -} - -static inline bool memcg_kmem_bypass(void) -{ - if (in_interrupt() || !current->mm || (current->flags & PF_KTHREAD)) - return true; - return false; -} - /** - * memcg_kmem_get_cache: select the correct per-memcg cache for allocation - * @cachep: the original global kmem cache - * - * Return the kmem_cache we're supposed to use for a slab allocation. - * We try to use the current memcg's version of the cache. - * - * If the cache does not exist yet, if we are the first user of it, we - * create it asynchronously in a workqueue and let the current allocation - * go through with the original cache. - * - * This function takes a reference to the cache it returns to assure it - * won't get destroyed while we are working with it. Once the caller is - * done with it, memcg_kmem_put_cache() must be called to release the - * reference. - */ -struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep) -{ - struct mem_cgroup *memcg; - struct kmem_cache *memcg_cachep; - int kmemcg_id; - - VM_BUG_ON(!is_root_cache(cachep)); - - if (memcg_kmem_bypass()) - return cachep; - - if (current->memcg_kmem_skip_account) - return cachep; - - memcg = get_mem_cgroup_from_current(); - kmemcg_id = READ_ONCE(memcg->kmemcg_id); - if (kmemcg_id < 0) - goto out; - - memcg_cachep = cache_from_memcg_idx(cachep, kmemcg_id); - if (likely(memcg_cachep)) - return memcg_cachep; - - /* - * If we are in a safe context (can wait, and not in interrupt - * context), we could be be predictable and return right away. - * This would guarantee that the allocation being performed - * already belongs in the new cache. - * - * However, there are some clashes that can arrive from locking. - * For instance, because we acquire the slab_mutex while doing - * memcg_create_kmem_cache, this means no further allocation - * could happen with the slab_mutex held. So it's better to - * defer everything. - */ - memcg_schedule_kmem_cache_create(memcg, cachep); -out: - css_put(&memcg->css); - return cachep; -} - -/** - * memcg_kmem_put_cache: drop reference taken by memcg_kmem_get_cache - * @cachep: the cache returned by memcg_kmem_get_cache - */ -void memcg_kmem_put_cache(struct kmem_cache *cachep) -{ - if (!is_root_cache(cachep)) - css_put(&cachep->memcg_params.memcg->css); -} - -/** - * memcg_kmem_charge_memcg: charge a kmem page - * @page: page to charge - * @gfp: reclaim mode - * @order: allocation order + * __memcg_kmem_charge: charge a number of kernel pages to a memcg * @memcg: memory cgroup to charge + * @gfp: reclaim mode + * @nr_pages: number of pages to charge * * Returns 0 on success, an error code on failure. */ -int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order, - struct mem_cgroup *memcg) +int __memcg_kmem_charge(struct mem_cgroup *memcg, gfp_t gfp, + unsigned int nr_pages) { - unsigned int nr_pages = 1 << order; struct page_counter *counter; int ret; @@ -2664,43 +3099,54 @@ cancel_charge(memcg, nr_pages); return -ENOMEM; } - - page->mem_cgroup = memcg; - return 0; } /** - * memcg_kmem_charge: charge a kmem page to the current memory cgroup + * __memcg_kmem_uncharge: uncharge a number of kernel pages from a memcg + * @memcg: memcg to uncharge + * @nr_pages: number of pages to uncharge + */ +void __memcg_kmem_uncharge(struct mem_cgroup *memcg, unsigned int nr_pages) +{ + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) + page_counter_uncharge(&memcg->kmem, nr_pages); + + refill_stock(memcg, nr_pages); +} + +/** + * __memcg_kmem_charge_page: charge a kmem page to the current memory cgroup * @page: page to charge * @gfp: reclaim mode * @order: allocation order * * Returns 0 on success, an error code on failure. */ -int memcg_kmem_charge(struct page *page, gfp_t gfp, int order) +int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order) { struct mem_cgroup *memcg; int ret = 0; - if (mem_cgroup_disabled() || memcg_kmem_bypass()) - return 0; - memcg = get_mem_cgroup_from_current(); - if (!mem_cgroup_is_root(memcg)) { - ret = memcg_kmem_charge_memcg(page, gfp, order, memcg); - if (!ret) + if (memcg && !mem_cgroup_is_root(memcg)) { + ret = __memcg_kmem_charge(memcg, gfp, 1 << order); + if (!ret) { + page->mem_cgroup = memcg; __SetPageKmemcg(page); + return 0; + } + css_put(&memcg->css); } - css_put(&memcg->css); return ret; } + /** - * memcg_kmem_uncharge: uncharge a kmem page + * __memcg_kmem_uncharge_page: uncharge a kmem page * @page: page to uncharge * @order: allocation order */ -void memcg_kmem_uncharge(struct page *page, int order) +void __memcg_kmem_uncharge_page(struct page *page, int order) { struct mem_cgroup *memcg = page->mem_cgroup; unsigned int nr_pages = 1 << order; @@ -2709,43 +3155,179 @@ return; VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg), page); - - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) - page_counter_uncharge(&memcg->kmem, nr_pages); - - page_counter_uncharge(&memcg->memory, nr_pages); - if (do_memsw_account()) - page_counter_uncharge(&memcg->memsw, nr_pages); - + __memcg_kmem_uncharge(memcg, nr_pages); page->mem_cgroup = NULL; + css_put(&memcg->css); /* slab pages do not have PageKmemcg flag set */ if (PageKmemcg(page)) __ClearPageKmemcg(page); - - css_put_many(&memcg->css, nr_pages); } -#endif /* CONFIG_MEMCG_KMEM */ -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - -/* - * Because tail pages are not marked as "used", set it. We're under - * zone_lru_lock and migration entries setup in all page mappings. - */ -void mem_cgroup_split_huge_fixup(struct page *head) +static bool consume_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes) { - int i; + struct memcg_stock_pcp *stock; + unsigned long flags; + bool ret = false; - if (mem_cgroup_disabled()) + local_irq_save(flags); + + stock = this_cpu_ptr(&memcg_stock); + if (objcg == stock->cached_objcg && stock->nr_bytes >= nr_bytes) { + stock->nr_bytes -= nr_bytes; + ret = true; + } + + local_irq_restore(flags); + + return ret; +} + +static void drain_obj_stock(struct memcg_stock_pcp *stock) +{ + struct obj_cgroup *old = stock->cached_objcg; + + if (!old) return; - for (i = 1; i < HPAGE_PMD_NR; i++) - head[i].mem_cgroup = head->mem_cgroup; + if (stock->nr_bytes) { + unsigned int nr_pages = stock->nr_bytes >> PAGE_SHIFT; + unsigned int nr_bytes = stock->nr_bytes & (PAGE_SIZE - 1); - __mod_memcg_state(head->mem_cgroup, MEMCG_RSS_HUGE, -HPAGE_PMD_NR); + if (nr_pages) { + struct mem_cgroup *memcg; + + rcu_read_lock(); +retry: + memcg = obj_cgroup_memcg(old); + if (unlikely(!css_tryget(&memcg->css))) + goto retry; + rcu_read_unlock(); + + __memcg_kmem_uncharge(memcg, nr_pages); + css_put(&memcg->css); + } + + /* + * The leftover is flushed to the centralized per-memcg value. + * On the next attempt to refill obj stock it will be moved + * to a per-cpu stock (probably, on an other CPU), see + * refill_obj_stock(). + * + * How often it's flushed is a trade-off between the memory + * limit enforcement accuracy and potential CPU contention, + * so it might be changed in the future. + */ + atomic_add(nr_bytes, &old->nr_charged_bytes); + stock->nr_bytes = 0; + } + + obj_cgroup_put(old); + stock->cached_objcg = NULL; } -#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, + struct mem_cgroup *root_memcg) +{ + struct mem_cgroup *memcg; + + if (stock->cached_objcg) { + memcg = obj_cgroup_memcg(stock->cached_objcg); + if (memcg && mem_cgroup_is_descendant(memcg, root_memcg)) + return true; + } + + return false; +} + +static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes) +{ + struct memcg_stock_pcp *stock; + unsigned long flags; + + local_irq_save(flags); + + stock = this_cpu_ptr(&memcg_stock); + if (stock->cached_objcg != objcg) { /* reset if necessary */ + drain_obj_stock(stock); + obj_cgroup_get(objcg); + stock->cached_objcg = objcg; + stock->nr_bytes = atomic_xchg(&objcg->nr_charged_bytes, 0); + } + stock->nr_bytes += nr_bytes; + + if (stock->nr_bytes > PAGE_SIZE) + drain_obj_stock(stock); + + local_irq_restore(flags); +} + +int obj_cgroup_charge(struct obj_cgroup *objcg, gfp_t gfp, size_t size) +{ + struct mem_cgroup *memcg; + unsigned int nr_pages, nr_bytes; + int ret; + + if (consume_obj_stock(objcg, size)) + return 0; + + /* + * In theory, memcg->nr_charged_bytes can have enough + * pre-charged bytes to satisfy the allocation. However, + * flushing memcg->nr_charged_bytes requires two atomic + * operations, and memcg->nr_charged_bytes can't be big, + * so it's better to ignore it and try grab some new pages. + * memcg->nr_charged_bytes will be flushed in + * refill_obj_stock(), called from this function or + * independently later. + */ + rcu_read_lock(); +retry: + memcg = obj_cgroup_memcg(objcg); + if (unlikely(!css_tryget(&memcg->css))) + goto retry; + rcu_read_unlock(); + + nr_pages = size >> PAGE_SHIFT; + nr_bytes = size & (PAGE_SIZE - 1); + + if (nr_bytes) + nr_pages += 1; + + ret = __memcg_kmem_charge(memcg, gfp, nr_pages); + if (!ret && nr_bytes) + refill_obj_stock(objcg, PAGE_SIZE - nr_bytes); + + css_put(&memcg->css); + return ret; +} + +void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size) +{ + refill_obj_stock(objcg, size); +} + +#endif /* CONFIG_MEMCG_KMEM */ + +/* + * Because head->mem_cgroup is not set on tails, set it now. + */ +void split_page_memcg(struct page *head, unsigned int nr) +{ + struct mem_cgroup *memcg = head->mem_cgroup; + int kmemcg = PageKmemcg(head); + int i; + + if (mem_cgroup_disabled() || !memcg) + return; + + for (i = 1; i < nr; i++) { + head[i].mem_cgroup = memcg; + if (kmemcg) + __SetPageKmemcg(head + i); + } + css_get_many(&memcg->css, nr - 1); +} #ifdef CONFIG_MEMCG_SWAP /** @@ -2807,7 +3389,7 @@ * Make sure that the new limit (memsw or memory limit) doesn't * break our basic invariant rule memory.max <= memsw.max. */ - limits_invariant = memsw ? max >= memcg->memory.max : + limits_invariant = memsw ? max >= READ_ONCE(memcg->memory.max) : max <= memcg->memsw.max; if (!limits_invariant) { mutex_unlock(&memcg_max_mutex); @@ -2928,7 +3510,7 @@ * Test whether @memcg has children, dead or alive. Note that this * function doesn't care whether @memcg has use_hierarchy enabled and * returns %true if there are child csses according to the cgroup - * hierarchy. Testing use_hierarchy is the caller's responsiblity. + * hierarchy. Testing use_hierarchy is the caller's responsibility. */ static inline bool memcg_has_children(struct mem_cgroup *memcg) { @@ -2947,7 +3529,7 @@ */ static int mem_cgroup_force_empty(struct mem_cgroup *memcg) { - int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; + int nr_retries = MAX_RECLAIM_RETRIES; /* we call try-to-free pages for make this cgroup empty */ lru_add_drain_all(); @@ -3021,50 +3603,15 @@ return retval; } -struct accumulated_stats { - unsigned long stat[MEMCG_NR_STAT]; - unsigned long events[NR_VM_EVENT_ITEMS]; - unsigned long lru_pages[NR_LRU_LISTS]; - const unsigned int *stats_array; - const unsigned int *events_array; - int stats_size; - int events_size; -}; - -static void accumulate_memcg_tree(struct mem_cgroup *memcg, - struct accumulated_stats *acc) -{ - struct mem_cgroup *mi; - int i; - - for_each_mem_cgroup_tree(mi, memcg) { - for (i = 0; i < acc->stats_size; i++) - acc->stat[i] += memcg_page_state(mi, - acc->stats_array ? acc->stats_array[i] : i); - - for (i = 0; i < acc->events_size; i++) - acc->events[i] += memcg_sum_events(mi, - acc->events_array ? acc->events_array[i] : i); - - for (i = 0; i < NR_LRU_LISTS; i++) - acc->lru_pages[i] += - mem_cgroup_nr_lru_pages(mi, BIT(i)); - } -} - static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) { - unsigned long val = 0; + unsigned long val; if (mem_cgroup_is_root(memcg)) { - struct mem_cgroup *iter; - - for_each_mem_cgroup_tree(iter, memcg) { - val += memcg_page_state(iter, MEMCG_CACHE); - val += memcg_page_state(iter, MEMCG_RSS); - if (swap) - val += memcg_page_state(iter, MEMCG_SWAP); - } + val = memcg_page_state(memcg, NR_FILE_PAGES) + + memcg_page_state(memcg, NR_ANON_MAPPED); + if (swap) + val += memcg_page_state(memcg, MEMCG_SWAP); } else { if (!swap) val = page_counter_read(&memcg->memory); @@ -3125,9 +3672,61 @@ } } +static void memcg_flush_percpu_vmstats(struct mem_cgroup *memcg) +{ + unsigned long stat[MEMCG_NR_STAT] = {0}; + struct mem_cgroup *mi; + int node, cpu, i; + + for_each_online_cpu(cpu) + for (i = 0; i < MEMCG_NR_STAT; i++) + stat[i] += per_cpu(memcg->vmstats_percpu->stat[i], cpu); + + for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) + for (i = 0; i < MEMCG_NR_STAT; i++) + atomic_long_add(stat[i], &mi->vmstats[i]); + + for_each_node(node) { + struct mem_cgroup_per_node *pn = memcg->nodeinfo[node]; + struct mem_cgroup_per_node *pi; + + for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) + stat[i] = 0; + + for_each_online_cpu(cpu) + for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) + stat[i] += per_cpu( + pn->lruvec_stat_cpu->count[i], cpu); + + for (pi = pn; pi; pi = parent_nodeinfo(pi, node)) + for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) + atomic_long_add(stat[i], &pi->lruvec_stat[i]); + } +} + +static void memcg_flush_percpu_vmevents(struct mem_cgroup *memcg) +{ + unsigned long events[NR_VM_EVENT_ITEMS]; + struct mem_cgroup *mi; + int cpu, i; + + for (i = 0; i < NR_VM_EVENT_ITEMS; i++) + events[i] = 0; + + for_each_online_cpu(cpu) + for (i = 0; i < NR_VM_EVENT_ITEMS; i++) + events[i] += per_cpu(memcg->vmstats_percpu->events[i], + cpu); + + for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) + for (i = 0; i < NR_VM_EVENT_ITEMS; i++) + atomic_long_add(events[i], &mi->vmevents[i]); +} + #ifdef CONFIG_MEMCG_KMEM static int memcg_online_kmem(struct mem_cgroup *memcg) { + struct obj_cgroup *objcg; int memcg_id; if (cgroup_memory_nokmem) @@ -3140,7 +3739,16 @@ if (memcg_id < 0) return memcg_id; - static_branch_inc(&memcg_kmem_enabled_key); + objcg = obj_cgroup_alloc(); + if (!objcg) { + memcg_free_cache_id(memcg_id); + return -ENOMEM; + } + objcg->memcg = memcg; + rcu_assign_pointer(memcg->objcg, objcg); + + static_branch_enable(&memcg_kmem_enabled_key); + /* * A memory cgroup is considered kmem-online as soon as it gets * kmemcg_id. Setting the id after enabling static branching will @@ -3149,7 +3757,6 @@ */ memcg->kmemcg_id = memcg_id; memcg->kmem_state = KMEM_ONLINE; - INIT_LIST_HEAD(&memcg->kmem_caches); return 0; } @@ -3162,22 +3769,17 @@ if (memcg->kmem_state != KMEM_ONLINE) return; - /* - * Clear the online state before clearing memcg_caches array - * entries. The slab_mutex in memcg_deactivate_kmem_caches() - * guarantees that no cache will be created for this cgroup - * after we are done (see memcg_create_kmem_cache()). - */ + memcg->kmem_state = KMEM_ALLOCATED; - - memcg_deactivate_kmem_caches(memcg); - - kmemcg_id = memcg->kmemcg_id; - BUG_ON(kmemcg_id < 0); parent = parent_mem_cgroup(memcg); if (!parent) parent = root_mem_cgroup; + + memcg_reparent_objcgs(memcg, parent); + + kmemcg_id = memcg->kmemcg_id; + BUG_ON(kmemcg_id < 0); /* * Change kmemcg_id of this cgroup and all its descendants to the @@ -3207,12 +3809,6 @@ /* css_alloc() failed, offlining didn't happen */ if (unlikely(memcg->kmem_state == KMEM_ONLINE)) memcg_offline_kmem(memcg); - - if (memcg->kmem_state == KMEM_ALLOCATED) { - memcg_destroy_kmem_caches(memcg); - static_branch_dec(&memcg_kmem_enabled_key); - WARN_ON(page_counter_read(&memcg->kmem)); - } } #else static int memcg_online_kmem(struct mem_cgroup *memcg) @@ -3303,6 +3899,9 @@ ret = mem_cgroup_resize_max(memcg, nr_pages, true); break; case _KMEM: + pr_warn_once("kmem.limit_in_bytes is deprecated and will be removed. " + "Please report your usecase to linux-mm@kvack.org if you " + "depend on this functionality.\n"); ret = memcg_update_kmem_max(memcg, nr_pages); break; case _TCP: @@ -3367,6 +3966,10 @@ { struct mem_cgroup *memcg = mem_cgroup_from_css(css); + pr_warn_once("Cgroup memory moving (move_charge_at_immigrate) is deprecated. " + "Please report your usecase to linux-mm@kvack.org if you " + "depend on this functionality.\n"); + if (val & ~MOVE_MASK) return -EINVAL; @@ -3388,6 +3991,49 @@ #endif #ifdef CONFIG_NUMA + +#define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE)) +#define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON)) +#define LRU_ALL ((1 << NR_LRU_LISTS) - 1) + +static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, + int nid, unsigned int lru_mask, bool tree) +{ + struct lruvec *lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid)); + unsigned long nr = 0; + enum lru_list lru; + + VM_BUG_ON((unsigned)nid >= nr_node_ids); + + for_each_lru(lru) { + if (!(BIT(lru) & lru_mask)) + continue; + if (tree) + nr += lruvec_page_state(lruvec, NR_LRU_BASE + lru); + else + nr += lruvec_page_state_local(lruvec, NR_LRU_BASE + lru); + } + return nr; +} + +static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, + unsigned int lru_mask, + bool tree) +{ + unsigned long nr = 0; + enum lru_list lru; + + for_each_lru(lru) { + if (!(BIT(lru) & lru_mask)) + continue; + if (tree) + nr += memcg_page_state(memcg, NR_LRU_BASE + lru); + else + nr += memcg_page_state_local(memcg, NR_LRU_BASE + lru); + } + return nr; +} + static int memcg_numa_stat_show(struct seq_file *m, void *v) { struct numa_stat { @@ -3403,40 +4049,60 @@ }; const struct numa_stat *stat; int nid; - unsigned long nr; - struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); + struct mem_cgroup *memcg = mem_cgroup_from_seq(m); for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { - nr = mem_cgroup_nr_lru_pages(memcg, stat->lru_mask); - seq_printf(m, "%s=%lu", stat->name, nr); - for_each_node_state(nid, N_MEMORY) { - nr = mem_cgroup_node_nr_lru_pages(memcg, nid, - stat->lru_mask); - seq_printf(m, " N%d=%lu", nid, nr); - } + seq_printf(m, "%s=%lu", stat->name, + mem_cgroup_nr_lru_pages(memcg, stat->lru_mask, + false)); + for_each_node_state(nid, N_MEMORY) + seq_printf(m, " N%d=%lu", nid, + mem_cgroup_node_nr_lru_pages(memcg, nid, + stat->lru_mask, false)); seq_putc(m, '\n'); } for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { - struct mem_cgroup *iter; - nr = 0; - for_each_mem_cgroup_tree(iter, memcg) - nr += mem_cgroup_nr_lru_pages(iter, stat->lru_mask); - seq_printf(m, "hierarchical_%s=%lu", stat->name, nr); - for_each_node_state(nid, N_MEMORY) { - nr = 0; - for_each_mem_cgroup_tree(iter, memcg) - nr += mem_cgroup_node_nr_lru_pages( - iter, nid, stat->lru_mask); - seq_printf(m, " N%d=%lu", nid, nr); - } + seq_printf(m, "hierarchical_%s=%lu", stat->name, + mem_cgroup_nr_lru_pages(memcg, stat->lru_mask, + true)); + for_each_node_state(nid, N_MEMORY) + seq_printf(m, " N%d=%lu", nid, + mem_cgroup_node_nr_lru_pages(memcg, nid, + stat->lru_mask, true)); seq_putc(m, '\n'); } return 0; } #endif /* CONFIG_NUMA */ + +static const unsigned int memcg1_stats[] = { + NR_FILE_PAGES, + NR_ANON_MAPPED, +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + NR_ANON_THPS, +#endif + NR_SHMEM, + NR_FILE_MAPPED, + NR_FILE_DIRTY, + NR_WRITEBACK, + MEMCG_SWAP, +}; + +static const char *const memcg1_stat_names[] = { + "cache", + "rss", +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + "rss_huge", +#endif + "shmem", + "mapped_file", + "dirty", + "writeback", + "swap", +}; /* Universal VM events cgroup1 shows, original sort order */ static const unsigned int memcg1_events[] = { @@ -3446,45 +4112,42 @@ PGMAJFAULT, }; -static const char *const memcg1_event_names[] = { - "pgpgin", - "pgpgout", - "pgfault", - "pgmajfault", -}; - static int memcg_stat_show(struct seq_file *m, void *v) { - struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); + struct mem_cgroup *memcg = mem_cgroup_from_seq(m); unsigned long memory, memsw; struct mem_cgroup *mi; unsigned int i; - struct accumulated_stats acc; BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names) != ARRAY_SIZE(memcg1_stats)); - BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS); for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { + unsigned long nr; + if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account()) continue; - seq_printf(m, "%s %lu\n", memcg1_stat_names[i], - memcg_page_state(memcg, memcg1_stats[i]) * - PAGE_SIZE); + nr = memcg_page_state_local(memcg, memcg1_stats[i]); +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + if (memcg1_stats[i] == NR_ANON_THPS) + nr *= HPAGE_PMD_NR; +#endif + seq_printf(m, "%s %lu\n", memcg1_stat_names[i], nr * PAGE_SIZE); } for (i = 0; i < ARRAY_SIZE(memcg1_events); i++) - seq_printf(m, "%s %lu\n", memcg1_event_names[i], - memcg_sum_events(memcg, memcg1_events[i])); + seq_printf(m, "%s %lu\n", vm_event_name(memcg1_events[i]), + memcg_events_local(memcg, memcg1_events[i])); for (i = 0; i < NR_LRU_LISTS; i++) - seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i], - mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE); + seq_printf(m, "%s %lu\n", lru_list_name(i), + memcg_page_state_local(memcg, NR_LRU_BASE + i) * + PAGE_SIZE); /* Hierarchical information */ memory = memsw = PAGE_COUNTER_MAX; for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) { - memory = min(memory, mi->memory.max); - memsw = min(memsw, mi->memsw.max); + memory = min(memory, READ_ONCE(mi->memory.max)); + memsw = min(memsw, READ_ONCE(mi->memsw.max)); } seq_printf(m, "hierarchical_memory_limit %llu\n", (u64)memory * PAGE_SIZE); @@ -3492,49 +4155,45 @@ seq_printf(m, "hierarchical_memsw_limit %llu\n", (u64)memsw * PAGE_SIZE); - memset(&acc, 0, sizeof(acc)); - acc.stats_size = ARRAY_SIZE(memcg1_stats); - acc.stats_array = memcg1_stats; - acc.events_size = ARRAY_SIZE(memcg1_events); - acc.events_array = memcg1_events; - accumulate_memcg_tree(memcg, &acc); - for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { + unsigned long nr; + if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account()) continue; + nr = memcg_page_state(memcg, memcg1_stats[i]); +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + if (memcg1_stats[i] == NR_ANON_THPS) + nr *= HPAGE_PMD_NR; +#endif seq_printf(m, "total_%s %llu\n", memcg1_stat_names[i], - (u64)acc.stat[i] * PAGE_SIZE); + (u64)nr * PAGE_SIZE); } for (i = 0; i < ARRAY_SIZE(memcg1_events); i++) - seq_printf(m, "total_%s %llu\n", memcg1_event_names[i], - (u64)acc.events[i]); + seq_printf(m, "total_%s %llu\n", + vm_event_name(memcg1_events[i]), + (u64)memcg_events(memcg, memcg1_events[i])); for (i = 0; i < NR_LRU_LISTS; i++) - seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], - (u64)acc.lru_pages[i] * PAGE_SIZE); + seq_printf(m, "total_%s %llu\n", lru_list_name(i), + (u64)memcg_page_state(memcg, NR_LRU_BASE + i) * + PAGE_SIZE); #ifdef CONFIG_DEBUG_VM { pg_data_t *pgdat; struct mem_cgroup_per_node *mz; - struct zone_reclaim_stat *rstat; - unsigned long recent_rotated[2] = {0, 0}; - unsigned long recent_scanned[2] = {0, 0}; + unsigned long anon_cost = 0; + unsigned long file_cost = 0; for_each_online_pgdat(pgdat) { mz = mem_cgroup_nodeinfo(memcg, pgdat->node_id); - rstat = &mz->lruvec.reclaim_stat; - recent_rotated[0] += rstat->recent_rotated[0]; - recent_rotated[1] += rstat->recent_rotated[1]; - recent_scanned[0] += rstat->recent_scanned[0]; - recent_scanned[1] += rstat->recent_scanned[1]; + anon_cost += mz->lruvec.anon_cost; + file_cost += mz->lruvec.file_cost; } - seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]); - seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]); - seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]); - seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]); + seq_printf(m, "anon_cost %lu\n", anon_cost); + seq_printf(m, "file_cost %lu\n", file_cost); } #endif @@ -3554,7 +4213,7 @@ { struct mem_cgroup *memcg = mem_cgroup_from_css(css); - if (val > 100) + if (val > 200) return -EINVAL; if (css->parent) @@ -3693,8 +4352,7 @@ 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); + new = kmalloc(struct_size(new, entries, size), GFP_KERNEL); if (!new) { ret = -ENOMEM; goto unlock; @@ -3702,17 +4360,16 @@ 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)); - } + if (thresholds->primary) + memcpy(new->entries, thresholds->primary->entries, + flex_array_size(new, entries, size - 1)); /* 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), + sort(new->entries, size, sizeof(*new->entries), compare_thresholds, NULL); /* Find current threshold */ @@ -3894,7 +4551,7 @@ static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v) { - struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(sf)); + struct mem_cgroup *memcg = mem_cgroup_from_seq(sf); seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable); seq_printf(sf, "under_oom %d\n", (bool)memcg->under_oom); @@ -3920,6 +4577,8 @@ } #ifdef CONFIG_CGROUP_WRITEBACK + +#include <trace/events/writeback.h> static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp) { @@ -3952,11 +4611,11 @@ */ static unsigned long memcg_exact_page_state(struct mem_cgroup *memcg, int idx) { - long x = atomic_long_read(&memcg->stat[idx]); + long x = atomic_long_read(&memcg->vmstats[idx]); int cpu; for_each_online_cpu(cpu) - x += per_cpu_ptr(memcg->stat_cpu, cpu)->count[idx]; + x += per_cpu_ptr(memcg->vmstats_percpu, cpu)->stat[idx]; if (x < 0) x = 0; return x; @@ -3989,18 +4648,142 @@ *pdirty = memcg_exact_page_state(memcg, NR_FILE_DIRTY); - /* this should eventually include NR_UNSTABLE_NFS */ *pwriteback = memcg_exact_page_state(memcg, NR_WRITEBACK); - *pfilepages = mem_cgroup_nr_lru_pages(memcg, (1 << LRU_INACTIVE_FILE) | - (1 << LRU_ACTIVE_FILE)); + *pfilepages = memcg_exact_page_state(memcg, NR_INACTIVE_FILE) + + memcg_exact_page_state(memcg, NR_ACTIVE_FILE); *pheadroom = PAGE_COUNTER_MAX; while ((parent = parent_mem_cgroup(memcg))) { - unsigned long ceiling = min(memcg->memory.max, memcg->high); + unsigned long ceiling = min(READ_ONCE(memcg->memory.max), + READ_ONCE(memcg->memory.high)); unsigned long used = page_counter_read(&memcg->memory); *pheadroom = min(*pheadroom, ceiling - min(ceiling, used)); memcg = parent; + } +} + +/* + * Foreign dirty flushing + * + * There's an inherent mismatch between memcg and writeback. The former + * trackes ownership per-page while the latter per-inode. This was a + * deliberate design decision because honoring per-page ownership in the + * writeback path is complicated, may lead to higher CPU and IO overheads + * and deemed unnecessary given that write-sharing an inode across + * different cgroups isn't a common use-case. + * + * Combined with inode majority-writer ownership switching, this works well + * enough in most cases but there are some pathological cases. For + * example, let's say there are two cgroups A and B which keep writing to + * different but confined parts of the same inode. B owns the inode and + * A's memory is limited far below B's. A's dirty ratio can rise enough to + * trigger balance_dirty_pages() sleeps but B's can be low enough to avoid + * triggering background writeback. A will be slowed down without a way to + * make writeback of the dirty pages happen. + * + * Conditions like the above can lead to a cgroup getting repatedly and + * severely throttled after making some progress after each + * dirty_expire_interval while the underyling IO device is almost + * completely idle. + * + * Solving this problem completely requires matching the ownership tracking + * granularities between memcg and writeback in either direction. However, + * the more egregious behaviors can be avoided by simply remembering the + * most recent foreign dirtying events and initiating remote flushes on + * them when local writeback isn't enough to keep the memory clean enough. + * + * The following two functions implement such mechanism. When a foreign + * page - a page whose memcg and writeback ownerships don't match - is + * dirtied, mem_cgroup_track_foreign_dirty() records the inode owning + * bdi_writeback on the page owning memcg. When balance_dirty_pages() + * decides that the memcg needs to sleep due to high dirty ratio, it calls + * mem_cgroup_flush_foreign() which queues writeback on the recorded + * foreign bdi_writebacks which haven't expired. Both the numbers of + * recorded bdi_writebacks and concurrent in-flight foreign writebacks are + * limited to MEMCG_CGWB_FRN_CNT. + * + * The mechanism only remembers IDs and doesn't hold any object references. + * As being wrong occasionally doesn't matter, updates and accesses to the + * records are lockless and racy. + */ +void mem_cgroup_track_foreign_dirty_slowpath(struct page *page, + struct bdi_writeback *wb) +{ + struct mem_cgroup *memcg = page->mem_cgroup; + struct memcg_cgwb_frn *frn; + u64 now = get_jiffies_64(); + u64 oldest_at = now; + int oldest = -1; + int i; + + trace_track_foreign_dirty(page, wb); + + /* + * Pick the slot to use. If there is already a slot for @wb, keep + * using it. If not replace the oldest one which isn't being + * written out. + */ + for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) { + frn = &memcg->cgwb_frn[i]; + if (frn->bdi_id == wb->bdi->id && + frn->memcg_id == wb->memcg_css->id) + break; + if (time_before64(frn->at, oldest_at) && + atomic_read(&frn->done.cnt) == 1) { + oldest = i; + oldest_at = frn->at; + } + } + + if (i < MEMCG_CGWB_FRN_CNT) { + /* + * Re-using an existing one. Update timestamp lazily to + * avoid making the cacheline hot. We want them to be + * reasonably up-to-date and significantly shorter than + * dirty_expire_interval as that's what expires the record. + * Use the shorter of 1s and dirty_expire_interval / 8. + */ + unsigned long update_intv = + min_t(unsigned long, HZ, + msecs_to_jiffies(dirty_expire_interval * 10) / 8); + + if (time_before64(frn->at, now - update_intv)) + frn->at = now; + } else if (oldest >= 0) { + /* replace the oldest free one */ + frn = &memcg->cgwb_frn[oldest]; + frn->bdi_id = wb->bdi->id; + frn->memcg_id = wb->memcg_css->id; + frn->at = now; + } +} + +/* issue foreign writeback flushes for recorded foreign dirtying events */ +void mem_cgroup_flush_foreign(struct bdi_writeback *wb) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); + unsigned long intv = msecs_to_jiffies(dirty_expire_interval * 10); + u64 now = jiffies_64; + int i; + + for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) { + struct memcg_cgwb_frn *frn = &memcg->cgwb_frn[i]; + + /* + * If the record is older than dirty_expire_interval, + * writeback on it has already started. No need to kick it + * off again. Also, don't start a new one if there's + * already one in flight. + */ + if (time_after64(frn->at, now - intv) && + atomic_read(&frn->done.cnt) == 1) { + frn->at = 0; + trace_flush_foreign(wb, frn->bdi_id, frn->memcg_id); + cgroup_writeback_by_id(frn->bdi_id, frn->memcg_id, 0, + WB_REASON_FOREIGN_FLUSH, + &frn->done); + } } } @@ -4123,6 +4906,7 @@ unsigned int efd, cfd; struct fd efile; struct fd cfile; + struct dentry *cdentry; const char *name; char *endp; int ret; @@ -4174,6 +4958,16 @@ goto out_put_cfile; /* + * The control file must be a regular cgroup1 file. As a regular cgroup + * file can't be renamed, it's safe to access its name afterwards. + */ + cdentry = cfile.file->f_path.dentry; + if (cdentry->d_sb->s_type != &cgroup_fs_type || !d_is_reg(cdentry)) { + ret = -EINVAL; + goto out_put_cfile; + } + + /* * Determine the event callbacks and set them in @event. This used * to be done via struct cftype but cgroup core no longer knows * about these events. The following is crude but the whole thing @@ -4181,7 +4975,7 @@ * * DO NOT ADD NEW FILES. */ - name = cfile.file->f_path.dentry->d_name.name; + name = cdentry->d_name.name; if (!strcmp(name, "memory.usage_in_bytes")) { event->register_event = mem_cgroup_usage_register_event; @@ -4205,7 +4999,7 @@ * automatically removed on cgroup destruction but the removal is * asynchronous, so take an extra ref on @css. */ - cfile_css = css_tryget_online_from_dir(cfile.file->f_path.dentry->d_parent, + cfile_css = css_tryget_online_from_dir(cdentry->d_parent, &memory_cgrp_subsys); ret = -EINVAL; if (IS_ERR(cfile_css)) @@ -4340,12 +5134,10 @@ .write = mem_cgroup_reset, .read_u64 = mem_cgroup_read_u64, }, -#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) +#if defined(CONFIG_MEMCG_KMEM) && \ + (defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)) { .name = "kmem.slabinfo", - .seq_start = memcg_slab_start, - .seq_next = memcg_slab_next, - .seq_stop = memcg_slab_stop, .seq_show = memcg_slab_show, }, #endif @@ -4383,7 +5175,7 @@ * limited to 16 bit (MEM_CGROUP_ID_MAX), limiting the total number of * memory-controlled cgroups to 64k. * - * However, there usually are many references to the oflline CSS after + * However, there usually are many references to the offline CSS after * the cgroup has been destroyed, such as page cache or reclaimable * slab objects, that don't need to hang on to the ID. We want to keep * those dead CSS from occupying IDs, or we might quickly exhaust the @@ -4404,31 +5196,26 @@ static void mem_cgroup_id_remove(struct mem_cgroup *memcg) { if (memcg->id.id > 0) { + trace_android_vh_mem_cgroup_id_remove(memcg); idr_remove(&mem_cgroup_idr, memcg->id.id); memcg->id.id = 0; } } -static void mem_cgroup_id_get_many(struct mem_cgroup *memcg, unsigned int n) +static void __maybe_unused mem_cgroup_id_get_many(struct mem_cgroup *memcg, + unsigned int n) { - VM_BUG_ON(atomic_read(&memcg->id.ref) <= 0); - atomic_add(n, &memcg->id.ref); + refcount_add(n, &memcg->id.ref); } static void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n) { - VM_BUG_ON(atomic_read(&memcg->id.ref) < n); - if (atomic_sub_and_test(n, &memcg->id.ref)) { + if (refcount_sub_and_test(n, &memcg->id.ref)) { mem_cgroup_id_remove(memcg); /* Memcg ID pins CSS */ css_put(&memcg->css); } -} - -static inline void mem_cgroup_id_get(struct mem_cgroup *memcg) -{ - mem_cgroup_id_get_many(memcg, 1); } static inline void mem_cgroup_id_put(struct mem_cgroup *memcg) @@ -4447,6 +5234,7 @@ WARN_ON_ONCE(!rcu_read_lock_held()); return idr_find(&mem_cgroup_idr, id); } +EXPORT_SYMBOL_GPL(mem_cgroup_from_id); static int alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) { @@ -4466,8 +5254,17 @@ if (!pn) return 1; - pn->lruvec_stat_cpu = alloc_percpu(struct lruvec_stat); + pn->lruvec_stat_local = alloc_percpu_gfp(struct lruvec_stat, + GFP_KERNEL_ACCOUNT); + if (!pn->lruvec_stat_local) { + kfree(pn); + return 1; + } + + pn->lruvec_stat_cpu = alloc_percpu_gfp(struct lruvec_stat, + GFP_KERNEL_ACCOUNT); if (!pn->lruvec_stat_cpu) { + free_percpu(pn->lruvec_stat_local); kfree(pn); return 1; } @@ -4489,6 +5286,7 @@ return; free_percpu(pn->lruvec_stat_cpu); + free_percpu(pn->lruvec_stat_local); kfree(pn); } @@ -4496,39 +5294,57 @@ { int node; + trace_android_vh_mem_cgroup_free(memcg); for_each_node(node) free_mem_cgroup_per_node_info(memcg, node); - free_percpu(memcg->stat_cpu); + free_percpu(memcg->vmstats_percpu); + free_percpu(memcg->vmstats_local); kfree(memcg); } static void mem_cgroup_free(struct mem_cgroup *memcg) { memcg_wb_domain_exit(memcg); + /* + * Flush percpu vmstats and vmevents to guarantee the value correctness + * on parent's and all ancestor levels. + */ + memcg_flush_percpu_vmstats(memcg); + memcg_flush_percpu_vmevents(memcg); __mem_cgroup_free(memcg); } static struct mem_cgroup *mem_cgroup_alloc(void) { struct mem_cgroup *memcg; - size_t size; + unsigned int size; int node; + int __maybe_unused i; + long error = -ENOMEM; size = sizeof(struct mem_cgroup); size += nr_node_ids * sizeof(struct mem_cgroup_per_node *); memcg = kzalloc(size, GFP_KERNEL); if (!memcg) - return NULL; + return ERR_PTR(error); memcg->id.id = idr_alloc(&mem_cgroup_idr, NULL, 1, MEM_CGROUP_ID_MAX, GFP_KERNEL); - if (memcg->id.id < 0) + if (memcg->id.id < 0) { + error = memcg->id.id; + goto fail; + } + + memcg->vmstats_local = alloc_percpu_gfp(struct memcg_vmstats_percpu, + GFP_KERNEL_ACCOUNT); + if (!memcg->vmstats_local) goto fail; - memcg->stat_cpu = alloc_percpu(struct mem_cgroup_stat_cpu); - if (!memcg->stat_cpu) + memcg->vmstats_percpu = alloc_percpu_gfp(struct memcg_vmstats_percpu, + GFP_KERNEL_ACCOUNT); + if (!memcg->vmstats_percpu) goto fail; for_each_node(node) @@ -4539,7 +5355,6 @@ goto fail; INIT_WORK(&memcg->high_work, high_work_func); - memcg->last_scanned_node = MAX_NUMNODES; INIT_LIST_HEAD(&memcg->oom_notify); mutex_init(&memcg->thresholds_lock); spin_lock_init(&memcg->move_lock); @@ -4549,48 +5364,64 @@ memcg->socket_pressure = jiffies; #ifdef CONFIG_MEMCG_KMEM memcg->kmemcg_id = -1; + INIT_LIST_HEAD(&memcg->objcg_list); #endif #ifdef CONFIG_CGROUP_WRITEBACK INIT_LIST_HEAD(&memcg->cgwb_list); + for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) + memcg->cgwb_frn[i].done = + __WB_COMPLETION_INIT(&memcg_cgwb_frn_waitq); +#endif +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + spin_lock_init(&memcg->deferred_split_queue.split_queue_lock); + INIT_LIST_HEAD(&memcg->deferred_split_queue.split_queue); + memcg->deferred_split_queue.split_queue_len = 0; #endif idr_replace(&mem_cgroup_idr, memcg, memcg->id.id); + trace_android_vh_mem_cgroup_alloc(memcg); return memcg; fail: mem_cgroup_id_remove(memcg); __mem_cgroup_free(memcg); - return NULL; + return ERR_PTR(error); } static struct cgroup_subsys_state * __ref mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) { struct mem_cgroup *parent = mem_cgroup_from_css(parent_css); - struct mem_cgroup *memcg; + struct mem_cgroup *memcg, *old_memcg; long error = -ENOMEM; + old_memcg = set_active_memcg(parent); memcg = mem_cgroup_alloc(); - if (!memcg) - return ERR_PTR(error); + set_active_memcg(old_memcg); + if (IS_ERR(memcg)) + return ERR_CAST(memcg); - memcg->high = PAGE_COUNTER_MAX; + page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX); memcg->soft_limit = PAGE_COUNTER_MAX; + page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX); if (parent) { memcg->swappiness = mem_cgroup_swappiness(parent); memcg->oom_kill_disable = parent->oom_kill_disable; } - if (parent && parent->use_hierarchy) { + if (!parent) { + page_counter_init(&memcg->memory, NULL); + page_counter_init(&memcg->swap, NULL); + page_counter_init(&memcg->kmem, NULL); + page_counter_init(&memcg->tcpmem, NULL); + } else if (parent->use_hierarchy) { memcg->use_hierarchy = true; page_counter_init(&memcg->memory, &parent->memory); page_counter_init(&memcg->swap, &parent->swap); - page_counter_init(&memcg->memsw, &parent->memsw); page_counter_init(&memcg->kmem, &parent->kmem); page_counter_init(&memcg->tcpmem, &parent->tcpmem); } else { - page_counter_init(&memcg->memory, NULL); - page_counter_init(&memcg->swap, NULL); - page_counter_init(&memcg->memsw, NULL); - page_counter_init(&memcg->kmem, NULL); - page_counter_init(&memcg->tcpmem, NULL); + page_counter_init(&memcg->memory, &root_mem_cgroup->memory); + page_counter_init(&memcg->swap, &root_mem_cgroup->swap); + page_counter_init(&memcg->kmem, &root_mem_cgroup->kmem); + page_counter_init(&memcg->tcpmem, &root_mem_cgroup->tcpmem); /* * Deeper hierachy with use_hierarchy == false doesn't make * much sense so let cgroup subsystem know about this @@ -4617,7 +5448,7 @@ fail: mem_cgroup_id_remove(memcg); mem_cgroup_free(memcg); - return ERR_PTR(-ENOMEM); + return ERR_PTR(error); } static int mem_cgroup_css_online(struct cgroup_subsys_state *css) @@ -4635,8 +5466,9 @@ } /* Online state pins memcg ID, memcg ID pins CSS */ - atomic_set(&memcg->id.ref, 1); + refcount_set(&memcg->id.ref, 1); css_get(css); + trace_android_vh_mem_cgroup_css_online(css, memcg); return 0; } @@ -4645,6 +5477,7 @@ struct mem_cgroup *memcg = mem_cgroup_from_css(css); struct mem_cgroup_event *event, *tmp; + trace_android_vh_mem_cgroup_css_offline(css, memcg); /* * Unregister events and notify userspace. * Notify userspace about cgroup removing only after rmdir of cgroup @@ -4663,6 +5496,8 @@ memcg_offline_kmem(memcg); wb_memcg_offline(memcg); + drain_all_stock(memcg); + mem_cgroup_id_put(memcg); } @@ -4676,7 +5511,12 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css) { struct mem_cgroup *memcg = mem_cgroup_from_css(css); + int __maybe_unused i; +#ifdef CONFIG_CGROUP_WRITEBACK + for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) + wb_wait_for_completion(&memcg->cgwb_frn[i].done); +#endif if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) static_branch_dec(&memcg_sockets_enabled_key); @@ -4710,13 +5550,13 @@ page_counter_set_max(&memcg->memory, PAGE_COUNTER_MAX); page_counter_set_max(&memcg->swap, PAGE_COUNTER_MAX); - page_counter_set_max(&memcg->memsw, PAGE_COUNTER_MAX); page_counter_set_max(&memcg->kmem, PAGE_COUNTER_MAX); page_counter_set_max(&memcg->tcpmem, PAGE_COUNTER_MAX); page_counter_set_min(&memcg->memory, 0); page_counter_set_low(&memcg->memory, 0); - memcg->high = PAGE_COUNTER_MAX; + page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX); memcg->soft_limit = PAGE_COUNTER_MAX; + page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX); memcg_wb_domain_size_changed(memcg); } @@ -4759,7 +5599,7 @@ 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, true); + struct page *page = vm_normal_page(vma, addr, ptent); if (!page || !page_mapped(page)) return NULL; @@ -4810,8 +5650,7 @@ * we call find_get_page() with swapper_space directly. */ page = find_get_page(swap_address_space(ent), swp_offset(ent)); - if (do_memsw_account()) - entry->val = ent.val; + entry->val = ent.val; return page; } @@ -4826,36 +5665,15 @@ static struct page *mc_handle_file_pte(struct vm_area_struct *vma, unsigned long addr, pte_t ptent, swp_entry_t *entry) { - struct page *page = NULL; - struct address_space *mapping; - pgoff_t pgoff; - if (!vma->vm_file) /* anonymous vma */ return NULL; if (!(mc.flags & MOVE_FILE)) return NULL; - mapping = vma->vm_file->f_mapping; - pgoff = linear_page_index(vma, addr); - /* page is moved even if it's not RSS of this task(page-faulted). */ -#ifdef CONFIG_SWAP /* shmem/tmpfs may report page out on swap: account for that too. */ - if (shmem_mapping(mapping)) { - page = find_get_entry(mapping, pgoff); - if (radix_tree_exceptional_entry(page)) { - swp_entry_t swp = radix_to_swp_entry(page); - if (do_memsw_account()) - *entry = swp; - page = find_get_page(swap_address_space(swp), - swp_offset(swp)); - } - } else - page = find_get_page(mapping, pgoff); -#else - page = find_get_page(mapping, pgoff); -#endif - return page; + return find_get_incore_page(vma->vm_file->f_mapping, + linear_page_index(vma, addr)); } /** @@ -4875,10 +5693,10 @@ struct mem_cgroup *from, struct mem_cgroup *to) { - unsigned long flags; - unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1; + struct lruvec *from_vec, *to_vec; + struct pglist_data *pgdat; + unsigned int nr_pages = compound ? thp_nr_pages(page) : 1; int ret; - bool anon; VM_BUG_ON(from == to); VM_BUG_ON_PAGE(PageLRU(page), page); @@ -4896,52 +5714,83 @@ if (page->mem_cgroup != from) goto out_unlock; - anon = PageAnon(page); + pgdat = page_pgdat(page); + from_vec = mem_cgroup_lruvec(from, pgdat); + to_vec = mem_cgroup_lruvec(to, pgdat); - spin_lock_irqsave(&from->move_lock, flags); + lock_page_memcg(page); - if (!anon && page_mapped(page)) { - __mod_memcg_state(from, NR_FILE_MAPPED, -nr_pages); - __mod_memcg_state(to, NR_FILE_MAPPED, nr_pages); - } + if (PageAnon(page)) { + if (page_mapped(page)) { + __mod_lruvec_state(from_vec, NR_ANON_MAPPED, -nr_pages); + __mod_lruvec_state(to_vec, NR_ANON_MAPPED, nr_pages); + if (PageTransHuge(page)) { + __dec_lruvec_state(from_vec, NR_ANON_THPS); + __inc_lruvec_state(to_vec, NR_ANON_THPS); + } - /* - * move_lock grabbed above and caller set from->moving_account, so - * mod_memcg_page_state will serialize updates to PageDirty. - * So mapping should be stable for dirty pages. - */ - if (!anon && PageDirty(page)) { - struct address_space *mapping = page_mapping(page); + } + } else { + __mod_lruvec_state(from_vec, NR_FILE_PAGES, -nr_pages); + __mod_lruvec_state(to_vec, NR_FILE_PAGES, nr_pages); - if (mapping_cap_account_dirty(mapping)) { - __mod_memcg_state(from, NR_FILE_DIRTY, -nr_pages); - __mod_memcg_state(to, NR_FILE_DIRTY, nr_pages); + if (PageSwapBacked(page)) { + __mod_lruvec_state(from_vec, NR_SHMEM, -nr_pages); + __mod_lruvec_state(to_vec, NR_SHMEM, nr_pages); + } + + if (page_mapped(page)) { + __mod_lruvec_state(from_vec, NR_FILE_MAPPED, -nr_pages); + __mod_lruvec_state(to_vec, NR_FILE_MAPPED, nr_pages); + } + + if (PageDirty(page)) { + struct address_space *mapping = page_mapping(page); + + if (mapping_can_writeback(mapping)) { + __mod_lruvec_state(from_vec, NR_FILE_DIRTY, + -nr_pages); + __mod_lruvec_state(to_vec, NR_FILE_DIRTY, + nr_pages); + } } } if (PageWriteback(page)) { - __mod_memcg_state(from, NR_WRITEBACK, -nr_pages); - __mod_memcg_state(to, NR_WRITEBACK, nr_pages); + __mod_lruvec_state(from_vec, NR_WRITEBACK, -nr_pages); + __mod_lruvec_state(to_vec, NR_WRITEBACK, nr_pages); } /* + * All state has been migrated, let's switch to the new memcg. + * * It is safe to change page->mem_cgroup here because the page - * is referenced, charged, and isolated - we can't race with - * uncharging, charging, migration, or LRU putback. + * is referenced, charged, isolated, and locked: we can't race + * with (un)charging, migration, LRU putback, or anything else + * that would rely on a stable page->mem_cgroup. + * + * Note that lock_page_memcg is a memcg lock, not a page lock, + * to save space. As soon as we switch page->mem_cgroup to a + * new memcg that isn't locked, the above state can change + * concurrently again. Make sure we're truly done with it. */ + smp_mb(); - /* caller should have done css_get */ + css_get(&to->css); + css_put(&from->css); + page->mem_cgroup = to; - spin_unlock_irqrestore(&from->move_lock, flags); + + __unlock_page_memcg(from); ret = 0; - local_lock_irq(event_lock); - mem_cgroup_charge_statistics(to, page, compound, nr_pages); + local_irq_disable(); + mem_cgroup_charge_statistics(to, page, nr_pages); memcg_check_events(to, page); - mem_cgroup_charge_statistics(from, page, compound, -nr_pages); + mem_cgroup_charge_statistics(from, page, -nr_pages); memcg_check_events(from, page); - local_unlock_irq(event_lock); + local_irq_enable(); out_unlock: unlock_page(page); out: @@ -4963,8 +5812,8 @@ * 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. - * 3(MC_TARGET_DEVICE): like MC_TARGET_PAGE but page is MEMORY_DEVICE_PUBLIC - * or MEMORY_DEVICE_PRIVATE (so ZONE_DEVICE page and thus not on the lru). + * 3(MC_TARGET_DEVICE): like MC_TARGET_PAGE but page is MEMORY_DEVICE_PRIVATE + * (so ZONE_DEVICE page and thus not on the lru). * For now we such page is charge like a regular page would be as for all * intent and purposes it is just special memory taking the place of a * regular page. @@ -4998,8 +5847,7 @@ */ if (page->mem_cgroup == mc.from) { ret = MC_TARGET_PAGE; - if (is_device_private_page(page) || - is_device_public_page(page)) + if (is_device_private_page(page)) ret = MC_TARGET_DEVICE; if (target) target->page = page; @@ -5070,8 +5918,8 @@ if (ptl) { /* * Note their can not be MC_TARGET_DEVICE for now as we do not - * support transparent huge page with MEMORY_DEVICE_PUBLIC or - * MEMORY_DEVICE_PRIVATE but this might change. + * support transparent huge page with MEMORY_DEVICE_PRIVATE but + * this might change. */ if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) mc.precharge += HPAGE_PMD_NR; @@ -5091,18 +5939,17 @@ return 0; } +static const struct mm_walk_ops precharge_walk_ops = { + .pmd_entry = mem_cgroup_count_precharge_pte_range, +}; + static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) { unsigned long precharge; - struct mm_walk mem_cgroup_count_precharge_walk = { - .pmd_entry = mem_cgroup_count_precharge_pte_range, - .mm = mm, - }; - down_read(&mm->mmap_sem); - walk_page_range(0, mm->highest_vm_end, - &mem_cgroup_count_precharge_walk); - up_read(&mm->mmap_sem); + mmap_read_lock(mm); + walk_page_range(mm, 0, mm->highest_vm_end, &precharge_walk_ops, NULL); + mmap_read_unlock(mm); precharge = mc.precharge; mc.precharge = 0; @@ -5152,8 +5999,6 @@ */ if (!mem_cgroup_is_root(mc.to)) page_counter_uncharge(&mc.to->memory, mc.moved_swap); - - css_put_many(&mc.to->css, mc.moved_swap); mc.moved_swap = 0; } @@ -5315,7 +6160,7 @@ switch (get_mctgt_type(vma, addr, ptent, &target)) { case MC_TARGET_DEVICE: device = true; - /* fall through */ + fallthrough; case MC_TARGET_PAGE: page = target.page; /* @@ -5370,13 +6215,12 @@ return ret; } +static const struct mm_walk_ops charge_walk_ops = { + .pmd_entry = mem_cgroup_move_charge_pte_range, +}; + static void mem_cgroup_move_charge(void) { - struct mm_walk mem_cgroup_move_charge_walk = { - .pmd_entry = mem_cgroup_move_charge_pte_range, - .mm = mc.mm, - }; - lru_add_drain_all(); /* * Signal lock_page_memcg() to take the memcg's move_lock @@ -5386,9 +6230,9 @@ atomic_inc(&mc.from->moving_account); synchronize_rcu(); retry: - if (unlikely(!down_read_trylock(&mc.mm->mmap_sem))) { + if (unlikely(!mmap_read_trylock(mc.mm))) { /* - * Someone who are holding the mmap_sem might be waiting in + * Someone who are holding the mmap_lock 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 @@ -5402,9 +6246,10 @@ * When we have consumed all precharges and failed in doing * additional charge, the page walk just aborts. */ - walk_page_range(0, mc.mm->highest_vm_end, &mem_cgroup_move_charge_walk); + walk_page_range(mc.mm, 0, mc.mm->highest_vm_end, &charge_walk_ops, + NULL); - up_read(&mc.mm->mmap_sem); + mmap_read_unlock(mc.mm); atomic_dec(&mc.from->moving_account); } @@ -5446,6 +6291,16 @@ root_mem_cgroup->use_hierarchy = false; } +static int seq_puts_memcg_tunable(struct seq_file *m, unsigned long value) +{ + if (value == PAGE_COUNTER_MAX) + seq_puts(m, "max\n"); + else + seq_printf(m, "%llu\n", (u64)value * PAGE_SIZE); + + return 0; +} + static u64 memory_current_read(struct cgroup_subsys_state *css, struct cftype *cft) { @@ -5456,15 +6311,8 @@ static int memory_min_show(struct seq_file *m, void *v) { - struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); - unsigned long min = READ_ONCE(memcg->memory.min); - - if (min == PAGE_COUNTER_MAX) - seq_puts(m, "max\n"); - else - seq_printf(m, "%llu\n", (u64)min * PAGE_SIZE); - - return 0; + return seq_puts_memcg_tunable(m, + READ_ONCE(mem_cgroup_from_seq(m)->memory.min)); } static ssize_t memory_min_write(struct kernfs_open_file *of, @@ -5486,15 +6334,8 @@ static int memory_low_show(struct seq_file *m, void *v) { - struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); - unsigned long low = READ_ONCE(memcg->memory.low); - - if (low == PAGE_COUNTER_MAX) - seq_puts(m, "max\n"); - else - seq_printf(m, "%llu\n", (u64)low * PAGE_SIZE); - - return 0; + return seq_puts_memcg_tunable(m, + READ_ONCE(mem_cgroup_from_seq(m)->memory.low)); } static ssize_t memory_low_write(struct kernfs_open_file *of, @@ -5516,22 +6357,16 @@ static int memory_high_show(struct seq_file *m, void *v) { - struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); - unsigned long high = READ_ONCE(memcg->high); - - if (high == PAGE_COUNTER_MAX) - seq_puts(m, "max\n"); - else - seq_printf(m, "%llu\n", (u64)high * PAGE_SIZE); - - return 0; + return seq_puts_memcg_tunable(m, + READ_ONCE(mem_cgroup_from_seq(m)->memory.high)); } static ssize_t memory_high_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); - unsigned long nr_pages; + unsigned int nr_retries = MAX_RECLAIM_RETRIES; + bool drained = false; unsigned long high; int err; @@ -5540,12 +6375,30 @@ if (err) return err; - memcg->high = high; + page_counter_set_high(&memcg->memory, high); - nr_pages = page_counter_read(&memcg->memory); - if (nr_pages > high) - try_to_free_mem_cgroup_pages(memcg, nr_pages - high, - GFP_KERNEL, true); + for (;;) { + unsigned long nr_pages = page_counter_read(&memcg->memory); + unsigned long reclaimed; + + if (nr_pages <= high) + break; + + if (signal_pending(current)) + break; + + if (!drained) { + drain_all_stock(memcg); + drained = true; + continue; + } + + reclaimed = try_to_free_mem_cgroup_pages(memcg, nr_pages - high, + GFP_KERNEL, true); + + if (!reclaimed && !nr_retries--) + break; + } memcg_wb_domain_size_changed(memcg); return nbytes; @@ -5553,22 +6406,15 @@ static int memory_max_show(struct seq_file *m, void *v) { - struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); - unsigned long max = READ_ONCE(memcg->memory.max); - - if (max == PAGE_COUNTER_MAX) - seq_puts(m, "max\n"); - else - seq_printf(m, "%llu\n", (u64)max * PAGE_SIZE); - - return 0; + return seq_puts_memcg_tunable(m, + READ_ONCE(mem_cgroup_from_seq(m)->memory.max)); } static ssize_t memory_max_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); - unsigned int nr_reclaims = MEM_CGROUP_RECLAIM_RETRIES; + unsigned int nr_reclaims = MAX_RECLAIM_RETRIES; bool drained = false; unsigned long max; int err; @@ -5586,10 +6432,8 @@ if (nr_pages <= max) break; - if (signal_pending(current)) { - err = -EINTR; + if (signal_pending(current)) break; - } if (!drained) { drain_all_stock(memcg); @@ -5613,104 +6457,77 @@ return nbytes; } +static void __memory_events_show(struct seq_file *m, atomic_long_t *events) +{ + seq_printf(m, "low %lu\n", atomic_long_read(&events[MEMCG_LOW])); + seq_printf(m, "high %lu\n", atomic_long_read(&events[MEMCG_HIGH])); + seq_printf(m, "max %lu\n", atomic_long_read(&events[MEMCG_MAX])); + seq_printf(m, "oom %lu\n", atomic_long_read(&events[MEMCG_OOM])); + seq_printf(m, "oom_kill %lu\n", + atomic_long_read(&events[MEMCG_OOM_KILL])); +} + static int memory_events_show(struct seq_file *m, void *v) { - struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); + struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - seq_printf(m, "low %lu\n", - atomic_long_read(&memcg->memory_events[MEMCG_LOW])); - seq_printf(m, "high %lu\n", - atomic_long_read(&memcg->memory_events[MEMCG_HIGH])); - seq_printf(m, "max %lu\n", - atomic_long_read(&memcg->memory_events[MEMCG_MAX])); - seq_printf(m, "oom %lu\n", - atomic_long_read(&memcg->memory_events[MEMCG_OOM])); - seq_printf(m, "oom_kill %lu\n", - atomic_long_read(&memcg->memory_events[MEMCG_OOM_KILL])); + __memory_events_show(m, memcg->memory_events); + return 0; +} +static int memory_events_local_show(struct seq_file *m, void *v) +{ + struct mem_cgroup *memcg = mem_cgroup_from_seq(m); + + __memory_events_show(m, memcg->memory_events_local); return 0; } static int memory_stat_show(struct seq_file *m, void *v) { - struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); - struct accumulated_stats acc; - int i; + struct mem_cgroup *memcg = mem_cgroup_from_seq(m); + char *buf; - /* - * Provide statistics on the state of the memory subsystem as - * well as cumulative event counters that show past behavior. - * - * This list is ordered following a combination of these gradients: - * 1) generic big picture -> specifics and details - * 2) reflecting userspace activity -> reflecting kernel heuristics - * - * Current memory state: - */ - - memset(&acc, 0, sizeof(acc)); - acc.stats_size = MEMCG_NR_STAT; - acc.events_size = NR_VM_EVENT_ITEMS; - accumulate_memcg_tree(memcg, &acc); - - seq_printf(m, "anon %llu\n", - (u64)acc.stat[MEMCG_RSS] * PAGE_SIZE); - seq_printf(m, "file %llu\n", - (u64)acc.stat[MEMCG_CACHE] * PAGE_SIZE); - seq_printf(m, "kernel_stack %llu\n", - (u64)acc.stat[MEMCG_KERNEL_STACK_KB] * 1024); - seq_printf(m, "slab %llu\n", - (u64)(acc.stat[NR_SLAB_RECLAIMABLE] + - acc.stat[NR_SLAB_UNRECLAIMABLE]) * PAGE_SIZE); - seq_printf(m, "sock %llu\n", - (u64)acc.stat[MEMCG_SOCK] * PAGE_SIZE); - - seq_printf(m, "shmem %llu\n", - (u64)acc.stat[NR_SHMEM] * PAGE_SIZE); - seq_printf(m, "file_mapped %llu\n", - (u64)acc.stat[NR_FILE_MAPPED] * PAGE_SIZE); - seq_printf(m, "file_dirty %llu\n", - (u64)acc.stat[NR_FILE_DIRTY] * PAGE_SIZE); - seq_printf(m, "file_writeback %llu\n", - (u64)acc.stat[NR_WRITEBACK] * PAGE_SIZE); - - for (i = 0; i < NR_LRU_LISTS; i++) - seq_printf(m, "%s %llu\n", mem_cgroup_lru_names[i], - (u64)acc.lru_pages[i] * PAGE_SIZE); - - seq_printf(m, "slab_reclaimable %llu\n", - (u64)acc.stat[NR_SLAB_RECLAIMABLE] * PAGE_SIZE); - seq_printf(m, "slab_unreclaimable %llu\n", - (u64)acc.stat[NR_SLAB_UNRECLAIMABLE] * PAGE_SIZE); - - /* Accumulated memory events */ - - seq_printf(m, "pgfault %lu\n", acc.events[PGFAULT]); - seq_printf(m, "pgmajfault %lu\n", acc.events[PGMAJFAULT]); - - seq_printf(m, "pgrefill %lu\n", acc.events[PGREFILL]); - seq_printf(m, "pgscan %lu\n", acc.events[PGSCAN_KSWAPD] + - acc.events[PGSCAN_DIRECT]); - seq_printf(m, "pgsteal %lu\n", acc.events[PGSTEAL_KSWAPD] + - acc.events[PGSTEAL_DIRECT]); - seq_printf(m, "pgactivate %lu\n", acc.events[PGACTIVATE]); - seq_printf(m, "pgdeactivate %lu\n", acc.events[PGDEACTIVATE]); - seq_printf(m, "pglazyfree %lu\n", acc.events[PGLAZYFREE]); - seq_printf(m, "pglazyfreed %lu\n", acc.events[PGLAZYFREED]); - - seq_printf(m, "workingset_refault %lu\n", - acc.stat[WORKINGSET_REFAULT]); - seq_printf(m, "workingset_activate %lu\n", - acc.stat[WORKINGSET_ACTIVATE]); - seq_printf(m, "workingset_nodereclaim %lu\n", - acc.stat[WORKINGSET_NODERECLAIM]); - + buf = memory_stat_format(memcg); + if (!buf) + return -ENOMEM; + seq_puts(m, buf); + kfree(buf); return 0; } +#ifdef CONFIG_NUMA +static int memory_numa_stat_show(struct seq_file *m, void *v) +{ + int i; + struct mem_cgroup *memcg = mem_cgroup_from_seq(m); + + for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { + int nid; + + if (memory_stats[i].idx >= NR_VM_NODE_STAT_ITEMS) + continue; + + seq_printf(m, "%s", memory_stats[i].name); + for_each_node_state(nid, N_MEMORY) { + u64 size; + struct lruvec *lruvec; + + lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid)); + size = lruvec_page_state(lruvec, memory_stats[i].idx); + size *= memory_stats[i].ratio; + seq_printf(m, " N%d=%llu", nid, size); + } + seq_putc(m, '\n'); + } + + return 0; +} +#endif + static int memory_oom_group_show(struct seq_file *m, void *v) { - struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); + struct mem_cgroup *memcg = mem_cgroup_from_seq(m); seq_printf(m, "%d\n", memcg->oom_group); @@ -5776,10 +6593,21 @@ .seq_show = memory_events_show, }, { - .name = "stat", + .name = "events.local", .flags = CFTYPE_NOT_ON_ROOT, + .file_offset = offsetof(struct mem_cgroup, events_local_file), + .seq_show = memory_events_local_show, + }, + { + .name = "stat", .seq_show = memory_stat_show, }, +#ifdef CONFIG_NUMA + { + .name = "numa_stat", + .seq_show = memory_numa_stat_show, + }, +#endif { .name = "oom.group", .flags = CFTYPE_NOT_ON_ROOT | CFTYPE_NS_DELEGATABLE, @@ -5805,6 +6633,122 @@ .early_init = 0, }; +/* + * This function calculates an individual cgroup's effective + * protection which is derived from its own memory.min/low, its + * parent's and siblings' settings, as well as the actual memory + * distribution in the tree. + * + * The following rules apply to the effective protection values: + * + * 1. At the first level of reclaim, effective protection is equal to + * the declared protection in memory.min and memory.low. + * + * 2. To enable safe delegation of the protection configuration, at + * subsequent levels the effective protection is capped to the + * parent's effective protection. + * + * 3. To make complex and dynamic subtrees easier to configure, the + * user is allowed to overcommit the declared protection at a given + * level. If that is the case, the parent's effective protection is + * distributed to the children in proportion to how much protection + * they have declared and how much of it they are utilizing. + * + * This makes distribution proportional, but also work-conserving: + * if one cgroup claims much more protection than it uses memory, + * the unused remainder is available to its siblings. + * + * 4. Conversely, when the declared protection is undercommitted at a + * given level, the distribution of the larger parental protection + * budget is NOT proportional. A cgroup's protection from a sibling + * is capped to its own memory.min/low setting. + * + * 5. However, to allow protecting recursive subtrees from each other + * without having to declare each individual cgroup's fixed share + * of the ancestor's claim to protection, any unutilized - + * "floating" - protection from up the tree is distributed in + * proportion to each cgroup's *usage*. This makes the protection + * neutral wrt sibling cgroups and lets them compete freely over + * the shared parental protection budget, but it protects the + * subtree as a whole from neighboring subtrees. + * + * Note that 4. and 5. are not in conflict: 4. is about protecting + * against immediate siblings whereas 5. is about protecting against + * neighboring subtrees. + */ +static unsigned long effective_protection(unsigned long usage, + unsigned long parent_usage, + unsigned long setting, + unsigned long parent_effective, + unsigned long siblings_protected) +{ + unsigned long protected; + unsigned long ep; + + protected = min(usage, setting); + /* + * If all cgroups at this level combined claim and use more + * protection then what the parent affords them, distribute + * shares in proportion to utilization. + * + * We are using actual utilization rather than the statically + * claimed protection in order to be work-conserving: claimed + * but unused protection is available to siblings that would + * otherwise get a smaller chunk than what they claimed. + */ + if (siblings_protected > parent_effective) + return protected * parent_effective / siblings_protected; + + /* + * Ok, utilized protection of all children is within what the + * parent affords them, so we know whatever this child claims + * and utilizes is effectively protected. + * + * If there is unprotected usage beyond this value, reclaim + * will apply pressure in proportion to that amount. + * + * If there is unutilized protection, the cgroup will be fully + * shielded from reclaim, but we do return a smaller value for + * protection than what the group could enjoy in theory. This + * is okay. With the overcommit distribution above, effective + * protection is always dependent on how memory is actually + * consumed among the siblings anyway. + */ + ep = protected; + + /* + * If the children aren't claiming (all of) the protection + * afforded to them by the parent, distribute the remainder in + * proportion to the (unprotected) memory of each cgroup. That + * way, cgroups that aren't explicitly prioritized wrt each + * other compete freely over the allowance, but they are + * collectively protected from neighboring trees. + * + * We're using unprotected memory for the weight so that if + * some cgroups DO claim explicit protection, we don't protect + * the same bytes twice. + * + * Check both usage and parent_usage against the respective + * protected values. One should imply the other, but they + * aren't read atomically - make sure the division is sane. + */ + if (!(cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_RECURSIVE_PROT)) + return ep; + if (parent_effective > siblings_protected && + parent_usage > siblings_protected && + usage > protected) { + unsigned long unclaimed; + + unclaimed = parent_effective - siblings_protected; + unclaimed *= usage - protected; + unclaimed /= parent_usage - siblings_protected; + + ep += unclaimed; + } + + return ep; +} + /** * mem_cgroup_protected - check if memory consumption is in the normal range * @root: the top ancestor of the sub-tree being checked @@ -5812,259 +6756,125 @@ * * WARNING: This function is not stateless! It can only be used as part * of a top-down tree iteration, not for isolated queries. - * - * Returns one of the following: - * MEMCG_PROT_NONE: cgroup memory is not protected - * MEMCG_PROT_LOW: cgroup memory is protected as long there is - * an unprotected supply of reclaimable memory from other cgroups. - * MEMCG_PROT_MIN: cgroup memory is protected - * - * @root is exclusive; it is never protected when looked at directly - * - * To provide a proper hierarchical behavior, effective memory.min/low values - * are used. Below is the description of how effective memory.low is calculated. - * Effective memory.min values is calculated in the same way. - * - * Effective memory.low is always equal or less than the original memory.low. - * If there is no memory.low overcommittment (which is always true for - * top-level memory cgroups), these two values are equal. - * Otherwise, it's a part of parent's effective memory.low, - * calculated as a cgroup's memory.low usage divided by sum of sibling's - * memory.low usages, where memory.low usage is the size of actually - * protected memory. - * - * low_usage - * elow = min( memory.low, parent->elow * ------------------ ), - * siblings_low_usage - * - * | memory.current, if memory.current < memory.low - * low_usage = | - | 0, otherwise. - * - * - * Such definition of the effective memory.low provides the expected - * hierarchical behavior: parent's memory.low value is limiting - * children, unprotected memory is reclaimed first and cgroups, - * which are not using their guarantee do not affect actual memory - * distribution. - * - * For example, if there are memcgs A, A/B, A/C, A/D and A/E: - * - * A A/memory.low = 2G, A/memory.current = 6G - * //\\ - * BC DE B/memory.low = 3G B/memory.current = 2G - * C/memory.low = 1G C/memory.current = 2G - * D/memory.low = 0 D/memory.current = 2G - * E/memory.low = 10G E/memory.current = 0 - * - * and the memory pressure is applied, the following memory distribution - * is expected (approximately): - * - * A/memory.current = 2G - * - * B/memory.current = 1.3G - * C/memory.current = 0.6G - * D/memory.current = 0 - * E/memory.current = 0 - * - * These calculations require constant tracking of the actual low usages - * (see propagate_protected_usage()), as well as recursive calculation of - * effective memory.low values. But as we do call mem_cgroup_protected() - * path for each memory cgroup top-down from the reclaim, - * it's possible to optimize this part, and save calculated elow - * for next usage. This part is intentionally racy, but it's ok, - * as memory.low is a best-effort mechanism. */ -enum mem_cgroup_protection mem_cgroup_protected(struct mem_cgroup *root, - struct mem_cgroup *memcg) +void mem_cgroup_calculate_protection(struct mem_cgroup *root, + struct mem_cgroup *memcg) { + unsigned long usage, parent_usage; struct mem_cgroup *parent; - unsigned long emin, parent_emin; - unsigned long elow, parent_elow; - unsigned long usage; if (mem_cgroup_disabled()) - return MEMCG_PROT_NONE; + return; if (!root) root = root_mem_cgroup; + + /* + * Effective values of the reclaim targets are ignored so they + * can be stale. Have a look at mem_cgroup_protection for more + * details. + * TODO: calculation should be more robust so that we do not need + * that special casing. + */ if (memcg == root) - return MEMCG_PROT_NONE; + return; usage = page_counter_read(&memcg->memory); if (!usage) - return MEMCG_PROT_NONE; - - emin = memcg->memory.min; - elow = memcg->memory.low; + return; parent = parent_mem_cgroup(memcg); /* No parent means a non-hierarchical mode on v1 memcg */ if (!parent) - return MEMCG_PROT_NONE; + return; - if (parent == root) - goto exit; - - parent_emin = READ_ONCE(parent->memory.emin); - emin = min(emin, parent_emin); - if (emin && parent_emin) { - unsigned long min_usage, siblings_min_usage; - - min_usage = min(usage, memcg->memory.min); - siblings_min_usage = atomic_long_read( - &parent->memory.children_min_usage); - - if (min_usage && siblings_min_usage) - emin = min(emin, parent_emin * min_usage / - siblings_min_usage); + if (parent == root) { + memcg->memory.emin = READ_ONCE(memcg->memory.min); + memcg->memory.elow = READ_ONCE(memcg->memory.low); + return; } - parent_elow = READ_ONCE(parent->memory.elow); - elow = min(elow, parent_elow); - if (elow && parent_elow) { - unsigned long low_usage, siblings_low_usage; + parent_usage = page_counter_read(&parent->memory); - low_usage = min(usage, memcg->memory.low); - siblings_low_usage = atomic_long_read( - &parent->memory.children_low_usage); + WRITE_ONCE(memcg->memory.emin, effective_protection(usage, parent_usage, + READ_ONCE(memcg->memory.min), + READ_ONCE(parent->memory.emin), + atomic_long_read(&parent->memory.children_min_usage))); - if (low_usage && siblings_low_usage) - elow = min(elow, parent_elow * low_usage / - siblings_low_usage); - } - -exit: - memcg->memory.emin = emin; - memcg->memory.elow = elow; - - if (usage <= emin) - return MEMCG_PROT_MIN; - else if (usage <= elow) - return MEMCG_PROT_LOW; - else - return MEMCG_PROT_NONE; + WRITE_ONCE(memcg->memory.elow, effective_protection(usage, parent_usage, + READ_ONCE(memcg->memory.low), + READ_ONCE(parent->memory.elow), + atomic_long_read(&parent->memory.children_low_usage))); } /** - * mem_cgroup_try_charge - try charging a page + * __mem_cgroup_charge - charge a newly allocated page to a cgroup * @page: page to charge * @mm: mm context of the victim * @gfp_mask: reclaim mode - * @memcgp: charged memcg return - * @compound: charge the page as compound or small page * * Try to charge @page to the memcg that @mm belongs to, reclaiming * pages according to @gfp_mask if necessary. * - * Returns 0 on success, with *@memcgp pointing to the charged memcg. - * Otherwise, an error code is returned. - * - * After page->mapping has been set up, the caller must finalize the - * charge with mem_cgroup_commit_charge(). Or abort the transaction - * with mem_cgroup_cancel_charge() in case page instantiation fails. + * Returns 0 on success. Otherwise, an error code is returned. */ -int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm, - gfp_t gfp_mask, struct mem_cgroup **memcgp, - bool compound) +int __mem_cgroup_charge(struct page *page, struct mm_struct *mm, + gfp_t gfp_mask) { + unsigned int nr_pages = thp_nr_pages(page); struct mem_cgroup *memcg = NULL; - unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1; int ret = 0; - if (mem_cgroup_disabled()) - goto out; - if (PageSwapCache(page)) { + swp_entry_t ent = { .val = page_private(page), }; + unsigned short id; + /* * Every swap fault against a single page tries to charge the * page, bail as early as possible. shmem_unuse() encounters - * already charged pages, too. The USED bit is protected by - * the page lock, which serializes swap cache removal, which + * already charged pages, too. page->mem_cgroup is protected + * by the page lock, which serializes swap cache removal, which * in turn serializes uncharging. */ VM_BUG_ON_PAGE(!PageLocked(page), page); if (compound_head(page)->mem_cgroup) goto out; - if (do_swap_account) { - swp_entry_t ent = { .val = page_private(page), }; - unsigned short id = lookup_swap_cgroup_id(ent); - - rcu_read_lock(); - memcg = mem_cgroup_from_id(id); - if (memcg && !css_tryget_online(&memcg->css)) - memcg = NULL; - rcu_read_unlock(); - } + id = lookup_swap_cgroup_id(ent); + rcu_read_lock(); + memcg = mem_cgroup_from_id(id); + if (memcg && !css_tryget_online(&memcg->css)) + memcg = NULL; + rcu_read_unlock(); } if (!memcg) memcg = get_mem_cgroup_from_mm(mm); ret = try_charge(memcg, gfp_mask, nr_pages); + if (ret) + goto out_put; - css_put(&memcg->css); -out: - *memcgp = memcg; - return ret; -} + css_get(&memcg->css); + commit_charge(page, memcg); -int mem_cgroup_try_charge_delay(struct page *page, struct mm_struct *mm, - gfp_t gfp_mask, struct mem_cgroup **memcgp, - bool compound) -{ - struct mem_cgroup *memcg; - int ret; - - ret = mem_cgroup_try_charge(page, mm, gfp_mask, memcgp, compound); - memcg = *memcgp; - mem_cgroup_throttle_swaprate(memcg, page_to_nid(page), gfp_mask); - return ret; -} - -/** - * mem_cgroup_commit_charge - commit a page charge - * @page: page to charge - * @memcg: memcg to charge the page to - * @lrucare: page might be on LRU already - * @compound: charge the page as compound or small page - * - * Finalize a charge transaction started by mem_cgroup_try_charge(), - * after page->mapping has been set up. This must happen atomically - * as part of the page instantiation, i.e. under the page table lock - * for anonymous pages, under the page lock for page and swap cache. - * - * In addition, the page must not be on the LRU during the commit, to - * prevent racing with task migration. If it might be, use @lrucare. - * - * Use mem_cgroup_cancel_charge() to cancel the transaction instead. - */ -void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg, - bool lrucare, bool compound) -{ - unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1; - - VM_BUG_ON_PAGE(!page->mapping, page); - VM_BUG_ON_PAGE(PageLRU(page) && !lrucare, page); - - if (mem_cgroup_disabled()) - return; - /* - * Swap faults will attempt to charge the same page multiple - * times. But reuse_swap_page() might have removed the page - * from swapcache already, so we can't check PageSwapCache(). - */ - if (!memcg) - return; - - commit_charge(page, memcg, lrucare); - - local_lock_irq(event_lock); - mem_cgroup_charge_statistics(memcg, page, compound, nr_pages); + local_irq_disable(); + mem_cgroup_charge_statistics(memcg, page, nr_pages); memcg_check_events(memcg, page); - local_unlock_irq(event_lock); + local_irq_enable(); + /* + * Cgroup1's unified memory+swap counter has been charged with the + * new swapcache page, finish the transfer by uncharging the swap + * slot. The swap slot would also get uncharged when it dies, but + * it can stick around indefinitely and we'd count the page twice + * the entire time. + * + * Cgroup2 has separate resource counters for memory and swap, + * so this is a non-issue here. Memory and swap charge lifetimes + * correspond 1:1 to page and swap slot lifetimes: we charge the + * page to memory here, and uncharge swap when the slot is freed. + */ if (do_memsw_account() && PageSwapCache(page)) { swp_entry_t entry = { .val = page_private(page) }; /* @@ -6074,42 +6884,18 @@ */ mem_cgroup_uncharge_swap(entry, nr_pages); } -} -/** - * mem_cgroup_cancel_charge - cancel a page charge - * @page: page to charge - * @memcg: memcg to charge the page to - * @compound: charge the page as compound or small page - * - * Cancel a charge transaction started by mem_cgroup_try_charge(). - */ -void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg, - bool compound) -{ - unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1; - - if (mem_cgroup_disabled()) - return; - /* - * Swap faults will attempt to charge the same page multiple - * times. But reuse_swap_page() might have removed the page - * from swapcache already, so we can't check PageSwapCache(). - */ - if (!memcg) - return; - - cancel_charge(memcg, nr_pages); +out_put: + css_put(&memcg->css); +out: + return ret; } struct uncharge_gather { struct mem_cgroup *memcg; + unsigned long nr_pages; unsigned long pgpgout; - unsigned long nr_anon; - unsigned long nr_file; unsigned long nr_kmem; - unsigned long nr_huge; - unsigned long nr_shmem; struct page *dummy_page; }; @@ -6120,37 +6906,32 @@ static void uncharge_batch(const struct uncharge_gather *ug) { - unsigned long nr_pages = ug->nr_anon + ug->nr_file + ug->nr_kmem; unsigned long flags; if (!mem_cgroup_is_root(ug->memcg)) { - page_counter_uncharge(&ug->memcg->memory, nr_pages); + page_counter_uncharge(&ug->memcg->memory, ug->nr_pages); if (do_memsw_account()) - page_counter_uncharge(&ug->memcg->memsw, nr_pages); + page_counter_uncharge(&ug->memcg->memsw, ug->nr_pages); if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && ug->nr_kmem) page_counter_uncharge(&ug->memcg->kmem, ug->nr_kmem); memcg_oom_recover(ug->memcg); } - local_lock_irqsave(event_lock, flags); - __mod_memcg_state(ug->memcg, MEMCG_RSS, -ug->nr_anon); - __mod_memcg_state(ug->memcg, MEMCG_CACHE, -ug->nr_file); - __mod_memcg_state(ug->memcg, MEMCG_RSS_HUGE, -ug->nr_huge); - __mod_memcg_state(ug->memcg, NR_SHMEM, -ug->nr_shmem); + local_irq_save(flags); __count_memcg_events(ug->memcg, PGPGOUT, ug->pgpgout); - __this_cpu_add(ug->memcg->stat_cpu->nr_page_events, nr_pages); + __this_cpu_add(ug->memcg->vmstats_percpu->nr_page_events, ug->nr_pages); memcg_check_events(ug->memcg, ug->dummy_page); - local_unlock_irqrestore(event_lock, flags); + local_irq_restore(flags); - if (!mem_cgroup_is_root(ug->memcg)) - css_put_many(&ug->memcg->css, nr_pages); + /* drop reference from uncharge_page */ + css_put(&ug->memcg->css); } static void uncharge_page(struct page *page, struct uncharge_gather *ug) { + unsigned long nr_pages; + VM_BUG_ON_PAGE(PageLRU(page), page); - VM_BUG_ON_PAGE(page_count(page) && !is_zone_device_page(page) && - !PageHWPoison(page) , page); if (!page->mem_cgroup) return; @@ -6167,30 +6948,24 @@ uncharge_gather_clear(ug); } ug->memcg = page->mem_cgroup; + + /* pairs with css_put in uncharge_batch */ + css_get(&ug->memcg->css); } - if (!PageKmemcg(page)) { - unsigned int nr_pages = 1; + nr_pages = compound_nr(page); + ug->nr_pages += nr_pages; - if (PageTransHuge(page)) { - nr_pages <<= compound_order(page); - ug->nr_huge += nr_pages; - } - if (PageAnon(page)) - ug->nr_anon += nr_pages; - else { - ug->nr_file += nr_pages; - if (PageSwapBacked(page)) - ug->nr_shmem += nr_pages; - } + if (!PageKmemcg(page)) { ug->pgpgout++; } else { - ug->nr_kmem += 1 << compound_order(page); + ug->nr_kmem += nr_pages; __ClearPageKmemcg(page); } ug->dummy_page = page; page->mem_cgroup = NULL; + css_put(&ug->memcg->css); } static void uncharge_list(struct list_head *page_list) @@ -6219,18 +6994,14 @@ } /** - * mem_cgroup_uncharge - uncharge a page + * __mem_cgroup_uncharge - uncharge a page * @page: page to uncharge * - * Uncharge a page previously charged with mem_cgroup_try_charge() and - * mem_cgroup_commit_charge(). + * Uncharge a page previously charged with __mem_cgroup_charge(). */ -void mem_cgroup_uncharge(struct page *page) +void __mem_cgroup_uncharge(struct page *page) { struct uncharge_gather ug; - - if (mem_cgroup_disabled()) - return; /* Don't touch page->lru of any random page, pre-check: */ if (!page->mem_cgroup) @@ -6242,17 +7013,14 @@ } /** - * mem_cgroup_uncharge_list - uncharge a list of page + * __mem_cgroup_uncharge_list - uncharge a list of page * @page_list: list of pages to uncharge * * Uncharge a list of pages previously charged with - * mem_cgroup_try_charge() and mem_cgroup_commit_charge(). + * __mem_cgroup_charge(). */ -void mem_cgroup_uncharge_list(struct list_head *page_list) +void __mem_cgroup_uncharge_list(struct list_head *page_list) { - if (mem_cgroup_disabled()) - return; - if (!list_empty(page_list)) uncharge_list(page_list); } @@ -6271,7 +7039,6 @@ { struct mem_cgroup *memcg; unsigned int nr_pages; - bool compound; unsigned long flags; VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage); @@ -6293,20 +7060,19 @@ return; /* Force-charge the new page. The old one will be freed soon */ - compound = PageTransHuge(newpage); - nr_pages = compound ? hpage_nr_pages(newpage) : 1; + nr_pages = thp_nr_pages(newpage); page_counter_charge(&memcg->memory, nr_pages); if (do_memsw_account()) page_counter_charge(&memcg->memsw, nr_pages); - css_get_many(&memcg->css, nr_pages); - commit_charge(newpage, memcg, false); + css_get(&memcg->css); + commit_charge(newpage, memcg); - local_lock_irqsave(event_lock, flags); - mem_cgroup_charge_statistics(memcg, newpage, compound, nr_pages); + local_irq_save(flags); + mem_cgroup_charge_statistics(memcg, newpage, nr_pages); memcg_check_events(memcg, newpage); - local_unlock_irqrestore(event_lock, flags); + local_irq_restore(flags); } DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key); @@ -6329,7 +7095,7 @@ goto out; if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg->tcpmem_active) goto out; - if (css_tryget_online(&memcg->css)) + if (css_tryget(&memcg->css)) sk->sk_memcg = memcg; out: rcu_read_unlock(); @@ -6407,7 +7173,7 @@ if (!strcmp(token, "nokmem")) cgroup_memory_nokmem = true; } - return 0; + return 1; } __setup("cgroup.memory=", cgroup_memory); @@ -6422,17 +7188,6 @@ static int __init mem_cgroup_init(void) { int cpu, node; - -#ifdef CONFIG_MEMCG_KMEM - /* - * Kmem cache creation is mostly done with the slab_mutex held, - * so use a workqueue with limited concurrency to avoid stalling - * all worker threads in case lots of cgroups are created and - * destroyed simultaneously. - */ - memcg_kmem_cache_wq = alloc_workqueue("memcg_kmem_cache", 0, 1); - BUG_ON(!memcg_kmem_cache_wq); -#endif cpuhp_setup_state_nocalls(CPUHP_MM_MEMCQ_DEAD, "mm/memctrl:dead", NULL, memcg_hotplug_cpu_dead); @@ -6460,7 +7215,7 @@ #ifdef CONFIG_MEMCG_SWAP static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) { - while (!atomic_inc_not_zero(&memcg->id.ref)) { + while (!refcount_inc_not_zero(&memcg->id.ref)) { /* * The root cgroup cannot be destroyed, so it's refcount must * always be >= 1. @@ -6488,12 +7243,14 @@ struct mem_cgroup *memcg, *swap_memcg; unsigned int nr_entries; unsigned short oldid; - unsigned long flags; VM_BUG_ON_PAGE(PageLRU(page), page); VM_BUG_ON_PAGE(page_count(page), page); - if (!do_memsw_account()) + if (mem_cgroup_disabled()) + return; + + if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) return; memcg = page->mem_cgroup; @@ -6508,7 +7265,7 @@ * ancestor for the swap instead and transfer the memory+swap charge. */ swap_memcg = mem_cgroup_id_get_online(memcg); - nr_entries = hpage_nr_pages(page); + nr_entries = thp_nr_pages(page); /* Get references for the tail pages, too */ if (nr_entries > 1) mem_cgroup_id_get_many(swap_memcg, nr_entries - 1); @@ -6522,7 +7279,7 @@ if (!mem_cgroup_is_root(memcg)) page_counter_uncharge(&memcg->memory, nr_entries); - if (memcg != swap_memcg) { + if (!cgroup_memory_noswap && memcg != swap_memcg) { if (!mem_cgroup_is_root(swap_memcg)) page_counter_charge(&swap_memcg->memsw, nr_entries); page_counter_uncharge(&memcg->memsw, nr_entries); @@ -6534,21 +7291,15 @@ * important here to have the interrupts disabled because it is the * only synchronisation we have for updating the per-CPU variables. */ - local_lock_irqsave(event_lock, flags); -#ifndef CONFIG_PREEMPT_RT_BASE VM_BUG_ON(!irqs_disabled()); -#endif - mem_cgroup_charge_statistics(memcg, page, PageTransHuge(page), - -nr_entries); + mem_cgroup_charge_statistics(memcg, page, -nr_entries); memcg_check_events(memcg, page); - local_unlock_irqrestore(event_lock, flags); - if (!mem_cgroup_is_root(memcg)) - css_put_many(&memcg->css, nr_entries); + css_put(&memcg->css); } /** - * mem_cgroup_try_charge_swap - try charging swap space for a page + * __mem_cgroup_try_charge_swap - try charging swap space for a page * @page: page being added to swap * @entry: swap entry to charge * @@ -6556,14 +7307,14 @@ * * Returns 0 on success, -ENOMEM on failure. */ -int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) +int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) { - unsigned int nr_pages = hpage_nr_pages(page); + unsigned int nr_pages = thp_nr_pages(page); struct page_counter *counter; struct mem_cgroup *memcg; unsigned short oldid; - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) || !do_swap_account) + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) return 0; memcg = page->mem_cgroup; @@ -6579,7 +7330,7 @@ memcg = mem_cgroup_id_get_online(memcg); - if (!mem_cgroup_is_root(memcg) && + if (!cgroup_memory_noswap && !mem_cgroup_is_root(memcg) && !page_counter_try_charge(&memcg->swap, nr_pages, &counter)) { memcg_memory_event(memcg, MEMCG_SWAP_MAX); memcg_memory_event(memcg, MEMCG_SWAP_FAIL); @@ -6598,23 +7349,20 @@ } /** - * mem_cgroup_uncharge_swap - uncharge swap space + * __mem_cgroup_uncharge_swap - uncharge swap space * @entry: swap entry to uncharge * @nr_pages: the amount of swap space to uncharge */ -void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages) +void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages) { struct mem_cgroup *memcg; unsigned short id; - - if (!do_swap_account) - return; id = swap_cgroup_record(entry, 0, nr_pages); rcu_read_lock(); memcg = mem_cgroup_from_id(id); if (memcg) { - if (!mem_cgroup_is_root(memcg)) { + if (!cgroup_memory_noswap && !mem_cgroup_is_root(memcg)) { if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) page_counter_uncharge(&memcg->swap, nr_pages); else @@ -6630,7 +7378,7 @@ { long nr_swap_pages = get_nr_swap_pages(); - if (!do_swap_account || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) + if (cgroup_memory_noswap || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) return nr_swap_pages; for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) nr_swap_pages = min_t(long, nr_swap_pages, @@ -6647,36 +7395,33 @@ if (vm_swap_full()) return true; - if (!do_swap_account || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) + if (cgroup_memory_noswap || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) return false; memcg = page->mem_cgroup; if (!memcg) return false; - for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) - if (page_counter_read(&memcg->swap) * 2 >= memcg->swap.max) + for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) { + unsigned long usage = page_counter_read(&memcg->swap); + + if (usage * 2 >= READ_ONCE(memcg->swap.high) || + usage * 2 >= READ_ONCE(memcg->swap.max)) return true; + } return false; } -/* for remember boot option*/ -#ifdef CONFIG_MEMCG_SWAP_ENABLED -static int really_do_swap_account __initdata = 1; -#else -static int really_do_swap_account __initdata; -#endif - -static int __init enable_swap_account(char *s) +static int __init setup_swap_account(char *s) { if (!strcmp(s, "1")) - really_do_swap_account = 1; + cgroup_memory_noswap = 0; else if (!strcmp(s, "0")) - really_do_swap_account = 0; + cgroup_memory_noswap = 1; return 1; } -__setup("swapaccount=", enable_swap_account); +__setup("swapaccount=", setup_swap_account); static u64 swap_current_read(struct cgroup_subsys_state *css, struct cftype *cft) @@ -6686,17 +7431,33 @@ return (u64)page_counter_read(&memcg->swap) * PAGE_SIZE; } +static int swap_high_show(struct seq_file *m, void *v) +{ + return seq_puts_memcg_tunable(m, + READ_ONCE(mem_cgroup_from_seq(m)->swap.high)); +} + +static ssize_t swap_high_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); + unsigned long high; + int err; + + buf = strstrip(buf); + err = page_counter_memparse(buf, "max", &high); + if (err) + return err; + + page_counter_set_high(&memcg->swap, high); + + return nbytes; +} + static int swap_max_show(struct seq_file *m, void *v) { - struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); - unsigned long max = READ_ONCE(memcg->swap.max); - - if (max == PAGE_COUNTER_MAX) - seq_puts(m, "max\n"); - else - seq_printf(m, "%llu\n", (u64)max * PAGE_SIZE); - - return 0; + return seq_puts_memcg_tunable(m, + READ_ONCE(mem_cgroup_from_seq(m)->swap.max)); } static ssize_t swap_max_write(struct kernfs_open_file *of, @@ -6718,8 +7479,10 @@ static int swap_events_show(struct seq_file *m, void *v) { - struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); + struct mem_cgroup *memcg = mem_cgroup_from_seq(m); + seq_printf(m, "high %lu\n", + atomic_long_read(&memcg->memory_events[MEMCG_SWAP_HIGH])); seq_printf(m, "max %lu\n", atomic_long_read(&memcg->memory_events[MEMCG_SWAP_MAX])); seq_printf(m, "fail %lu\n", @@ -6733,6 +7496,12 @@ .name = "swap.current", .flags = CFTYPE_NOT_ON_ROOT, .read_u64 = swap_current_read, + }, + { + .name = "swap.high", + .flags = CFTYPE_NOT_ON_ROOT, + .seq_show = swap_high_show, + .write = swap_high_write, }, { .name = "swap.max", @@ -6749,7 +7518,7 @@ { } /* terminate */ }; -static struct cftype memsw_cgroup_files[] = { +static struct cftype memsw_files[] = { { .name = "memsw.usage_in_bytes", .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), @@ -6776,17 +7545,27 @@ { }, /* terminate */ }; +/* + * If mem_cgroup_swap_init() is implemented as a subsys_initcall() + * instead of a core_initcall(), this could mean cgroup_memory_noswap still + * remains set to false even when memcg is disabled via "cgroup_disable=memory" + * boot parameter. This may result in premature OOPS inside + * mem_cgroup_get_nr_swap_pages() function in corner cases. + */ static int __init mem_cgroup_swap_init(void) { - if (!mem_cgroup_disabled() && really_do_swap_account) { - do_swap_account = 1; - WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, - swap_files)); - WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, - memsw_cgroup_files)); - } + /* No memory control -> no swap control */ + if (mem_cgroup_disabled()) + cgroup_memory_noswap = true; + + if (cgroup_memory_noswap) + return 0; + + WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, swap_files)); + WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, memsw_files)); + return 0; } -subsys_initcall(mem_cgroup_swap_init); +core_initcall(mem_cgroup_swap_init); #endif /* CONFIG_MEMCG_SWAP */ -- Gitblit v1.6.2