5850 lines
148 KiB
C
5850 lines
148 KiB
C
/* memcontrol.c - Memory Controller
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*
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* Copyright IBM Corporation, 2007
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* Author Balbir Singh <balbir@linux.vnet.ibm.com>
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*
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* Copyright 2007 OpenVZ SWsoft Inc
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* Author: Pavel Emelianov <xemul@openvz.org>
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*
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* Memory thresholds
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* Copyright (C) 2009 Nokia Corporation
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* Author: Kirill A. Shutemov
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*
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* Kernel Memory Controller
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* Copyright (C) 2012 Parallels Inc. and Google Inc.
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* Authors: Glauber Costa and Suleiman Souhlal
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/page_counter.h>
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#include <linux/memcontrol.h>
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#include <linux/cgroup.h>
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#include <linux/mm.h>
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#include <linux/hugetlb.h>
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#include <linux/pagemap.h>
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#include <linux/smp.h>
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#include <linux/page-flags.h>
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#include <linux/backing-dev.h>
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#include <linux/bit_spinlock.h>
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#include <linux/rcupdate.h>
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#include <linux/limits.h>
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#include <linux/export.h>
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#include <linux/mutex.h>
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#include <linux/rbtree.h>
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#include <linux/slab.h>
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#include <linux/swap.h>
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#include <linux/swapops.h>
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#include <linux/spinlock.h>
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#include <linux/eventfd.h>
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#include <linux/poll.h>
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#include <linux/sort.h>
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#include <linux/fs.h>
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#include <linux/seq_file.h>
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#include <linux/vmpressure.h>
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#include <linux/mm_inline.h>
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#include <linux/swap_cgroup.h>
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#include <linux/cpu.h>
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#include <linux/oom.h>
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#include <linux/lockdep.h>
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#include <linux/file.h>
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#include "internal.h"
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#include <net/sock.h>
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#include <net/ip.h>
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#include <net/tcp_memcontrol.h>
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#include "slab.h"
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#include <asm/uaccess.h>
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#include <trace/events/vmscan.h>
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struct cgroup_subsys memory_cgrp_subsys __read_mostly;
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EXPORT_SYMBOL(memory_cgrp_subsys);
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#define MEM_CGROUP_RECLAIM_RETRIES 5
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static struct mem_cgroup *root_mem_cgroup __read_mostly;
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#ifdef CONFIG_MEMCG_SWAP
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/* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
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int do_swap_account __read_mostly;
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/* for remember boot option*/
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#ifdef CONFIG_MEMCG_SWAP_ENABLED
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static int really_do_swap_account __initdata = 1;
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#else
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static int really_do_swap_account __initdata;
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#endif
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#else
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#define do_swap_account 0
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#endif
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static const char * const mem_cgroup_stat_names[] = {
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"cache",
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"rss",
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"rss_huge",
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"mapped_file",
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"writeback",
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"swap",
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};
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enum mem_cgroup_events_index {
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MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */
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MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */
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MEM_CGROUP_EVENTS_PGFAULT, /* # of page-faults */
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MEM_CGROUP_EVENTS_PGMAJFAULT, /* # of major page-faults */
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MEM_CGROUP_EVENTS_NSTATS,
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};
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static const char * const mem_cgroup_events_names[] = {
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"pgpgin",
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"pgpgout",
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"pgfault",
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"pgmajfault",
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};
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static const char * const mem_cgroup_lru_names[] = {
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"inactive_anon",
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"active_anon",
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"inactive_file",
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"active_file",
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"unevictable",
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};
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/*
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* Per memcg event counter is incremented at every pagein/pageout. With THP,
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* it will be incremated by the number of pages. This counter is used for
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* for trigger some periodic events. This is straightforward and better
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* than using jiffies etc. to handle periodic memcg event.
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*/
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enum mem_cgroup_events_target {
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MEM_CGROUP_TARGET_THRESH,
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MEM_CGROUP_TARGET_SOFTLIMIT,
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MEM_CGROUP_TARGET_NUMAINFO,
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MEM_CGROUP_NTARGETS,
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};
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#define THRESHOLDS_EVENTS_TARGET 128
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#define SOFTLIMIT_EVENTS_TARGET 1024
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#define NUMAINFO_EVENTS_TARGET 1024
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struct mem_cgroup_stat_cpu {
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long count[MEM_CGROUP_STAT_NSTATS];
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unsigned long events[MEM_CGROUP_EVENTS_NSTATS];
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unsigned long nr_page_events;
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unsigned long targets[MEM_CGROUP_NTARGETS];
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};
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struct reclaim_iter {
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struct mem_cgroup *position;
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/* scan generation, increased every round-trip */
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unsigned int generation;
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};
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/*
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* per-zone information in memory controller.
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*/
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struct mem_cgroup_per_zone {
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struct lruvec lruvec;
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unsigned long lru_size[NR_LRU_LISTS];
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struct reclaim_iter iter[DEF_PRIORITY + 1];
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struct rb_node tree_node; /* RB tree node */
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unsigned long usage_in_excess;/* Set to the value by which */
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/* the soft limit is exceeded*/
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bool on_tree;
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struct mem_cgroup *memcg; /* Back pointer, we cannot */
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/* use container_of */
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};
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struct mem_cgroup_per_node {
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struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
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};
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/*
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* Cgroups above their limits are maintained in a RB-Tree, independent of
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* their hierarchy representation
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*/
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struct mem_cgroup_tree_per_zone {
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struct rb_root rb_root;
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spinlock_t lock;
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};
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struct mem_cgroup_tree_per_node {
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struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES];
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};
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struct mem_cgroup_tree {
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struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
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};
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static struct mem_cgroup_tree soft_limit_tree __read_mostly;
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struct mem_cgroup_threshold {
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struct eventfd_ctx *eventfd;
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unsigned long threshold;
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};
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/* For threshold */
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struct mem_cgroup_threshold_ary {
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/* An array index points to threshold just below or equal to usage. */
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int current_threshold;
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/* Size of entries[] */
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unsigned int size;
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/* Array of thresholds */
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struct mem_cgroup_threshold entries[0];
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};
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struct mem_cgroup_thresholds {
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/* Primary thresholds array */
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struct mem_cgroup_threshold_ary *primary;
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/*
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* Spare threshold array.
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* This is needed to make mem_cgroup_unregister_event() "never fail".
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* It must be able to store at least primary->size - 1 entries.
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*/
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struct mem_cgroup_threshold_ary *spare;
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};
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/* for OOM */
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struct mem_cgroup_eventfd_list {
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struct list_head list;
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struct eventfd_ctx *eventfd;
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};
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/*
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* cgroup_event represents events which userspace want to receive.
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*/
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struct mem_cgroup_event {
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/*
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* memcg which the event belongs to.
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*/
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struct mem_cgroup *memcg;
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/*
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* eventfd to signal userspace about the event.
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*/
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struct eventfd_ctx *eventfd;
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/*
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* Each of these stored in a list by the cgroup.
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*/
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struct list_head list;
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/*
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* register_event() callback will be used to add new userspace
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* waiter for changes related to this event. Use eventfd_signal()
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* on eventfd to send notification to userspace.
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*/
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int (*register_event)(struct mem_cgroup *memcg,
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struct eventfd_ctx *eventfd, const char *args);
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/*
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* unregister_event() callback will be called when userspace closes
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* the eventfd or on cgroup removing. This callback must be set,
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* if you want provide notification functionality.
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*/
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void (*unregister_event)(struct mem_cgroup *memcg,
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struct eventfd_ctx *eventfd);
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/*
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* All fields below needed to unregister event when
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* userspace closes eventfd.
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*/
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poll_table pt;
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wait_queue_head_t *wqh;
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wait_queue_t wait;
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struct work_struct remove;
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};
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static void mem_cgroup_threshold(struct mem_cgroup *memcg);
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static void mem_cgroup_oom_notify(struct mem_cgroup *memcg);
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/*
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* The memory controller data structure. The memory controller controls both
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* page cache and RSS per cgroup. We would eventually like to provide
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* statistics based on the statistics developed by Rik Van Riel for clock-pro,
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* to help the administrator determine what knobs to tune.
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*
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* TODO: Add a water mark for the memory controller. Reclaim will begin when
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* we hit the water mark. May be even add a low water mark, such that
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* no reclaim occurs from a cgroup at it's low water mark, this is
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* a feature that will be implemented much later in the future.
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*/
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struct mem_cgroup {
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struct cgroup_subsys_state css;
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/* Accounted resources */
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struct page_counter memory;
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struct page_counter memsw;
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struct page_counter kmem;
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unsigned long soft_limit;
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/* vmpressure notifications */
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struct vmpressure vmpressure;
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/* css_online() has been completed */
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int initialized;
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/*
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* Should the accounting and control be hierarchical, per subtree?
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*/
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bool use_hierarchy;
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bool oom_lock;
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atomic_t under_oom;
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atomic_t oom_wakeups;
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int swappiness;
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/* OOM-Killer disable */
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int oom_kill_disable;
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/* protect arrays of thresholds */
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struct mutex thresholds_lock;
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/* thresholds for memory usage. RCU-protected */
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struct mem_cgroup_thresholds thresholds;
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/* thresholds for mem+swap usage. RCU-protected */
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struct mem_cgroup_thresholds memsw_thresholds;
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/* For oom notifier event fd */
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struct list_head oom_notify;
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/*
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* Should we move charges of a task when a task is moved into this
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* mem_cgroup ? And what type of charges should we move ?
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*/
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unsigned long move_charge_at_immigrate;
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/*
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* set > 0 if pages under this cgroup are moving to other cgroup.
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*/
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atomic_t moving_account;
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/* taken only while moving_account > 0 */
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spinlock_t move_lock;
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/*
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* percpu counter.
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*/
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struct mem_cgroup_stat_cpu __percpu *stat;
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/*
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* used when a cpu is offlined or other synchronizations
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* See mem_cgroup_read_stat().
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*/
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struct mem_cgroup_stat_cpu nocpu_base;
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spinlock_t pcp_counter_lock;
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#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
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struct cg_proto tcp_mem;
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#endif
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#if defined(CONFIG_MEMCG_KMEM)
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/* analogous to slab_common's slab_caches list, but per-memcg;
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* protected by memcg_slab_mutex */
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struct list_head memcg_slab_caches;
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/* Index in the kmem_cache->memcg_params->memcg_caches array */
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int kmemcg_id;
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#endif
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int last_scanned_node;
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#if MAX_NUMNODES > 1
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nodemask_t scan_nodes;
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atomic_t numainfo_events;
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atomic_t numainfo_updating;
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#endif
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/* List of events which userspace want to receive */
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struct list_head event_list;
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spinlock_t event_list_lock;
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struct mem_cgroup_per_node *nodeinfo[0];
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/* WARNING: nodeinfo must be the last member here */
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};
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#ifdef CONFIG_MEMCG_KMEM
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static bool memcg_kmem_is_active(struct mem_cgroup *memcg)
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{
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return memcg->kmemcg_id >= 0;
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}
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#endif
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/* Stuffs for move charges at task migration. */
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/*
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* Types of charges to be moved. "move_charge_at_immitgrate" and
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* "immigrate_flags" are treated as a left-shifted bitmap of these types.
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*/
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enum move_type {
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MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */
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MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */
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NR_MOVE_TYPE,
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};
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/* "mc" and its members are protected by cgroup_mutex */
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static struct move_charge_struct {
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spinlock_t lock; /* for from, to */
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struct mem_cgroup *from;
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struct mem_cgroup *to;
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unsigned long immigrate_flags;
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unsigned long precharge;
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unsigned long moved_charge;
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unsigned long moved_swap;
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struct task_struct *moving_task; /* a task moving charges */
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wait_queue_head_t waitq; /* a waitq for other context */
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} mc = {
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.lock = __SPIN_LOCK_UNLOCKED(mc.lock),
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.waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
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};
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static bool move_anon(void)
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{
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return test_bit(MOVE_CHARGE_TYPE_ANON, &mc.immigrate_flags);
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}
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static bool move_file(void)
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{
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return test_bit(MOVE_CHARGE_TYPE_FILE, &mc.immigrate_flags);
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}
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/*
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* Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
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* limit reclaim to prevent infinite loops, if they ever occur.
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*/
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#define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
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#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
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enum charge_type {
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MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
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MEM_CGROUP_CHARGE_TYPE_ANON,
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MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
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MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
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NR_CHARGE_TYPE,
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};
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/* for encoding cft->private value on file */
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enum res_type {
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_MEM,
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_MEMSWAP,
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_OOM_TYPE,
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_KMEM,
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};
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#define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
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#define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
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#define MEMFILE_ATTR(val) ((val) & 0xffff)
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/* Used for OOM nofiier */
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#define OOM_CONTROL (0)
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/*
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* The memcg_create_mutex will be held whenever a new cgroup is created.
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* As a consequence, any change that needs to protect against new child cgroups
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* appearing has to hold it as well.
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*/
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static DEFINE_MUTEX(memcg_create_mutex);
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struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s)
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{
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return s ? container_of(s, struct mem_cgroup, css) : NULL;
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}
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/* Some nice accessors for the vmpressure. */
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struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg)
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{
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if (!memcg)
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memcg = root_mem_cgroup;
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return &memcg->vmpressure;
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}
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struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr)
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{
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return &container_of(vmpr, struct mem_cgroup, vmpressure)->css;
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}
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static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
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{
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return (memcg == root_mem_cgroup);
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}
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/*
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* We restrict the id in the range of [1, 65535], so it can fit into
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* an unsigned short.
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*/
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#define MEM_CGROUP_ID_MAX USHRT_MAX
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static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
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{
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return memcg->css.id;
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}
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static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
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{
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struct cgroup_subsys_state *css;
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css = css_from_id(id, &memory_cgrp_subsys);
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return mem_cgroup_from_css(css);
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}
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/* Writing them here to avoid exposing memcg's inner layout */
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#if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
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void sock_update_memcg(struct sock *sk)
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{
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if (mem_cgroup_sockets_enabled) {
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struct mem_cgroup *memcg;
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struct cg_proto *cg_proto;
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BUG_ON(!sk->sk_prot->proto_cgroup);
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/* Socket cloning can throw us here with sk_cgrp already
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* filled. It won't however, necessarily happen from
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* process context. So the test for root memcg given
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* the current task's memcg won't help us in this case.
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*
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* Respecting the original socket's memcg is a better
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* decision in this case.
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*/
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if (sk->sk_cgrp) {
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BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg));
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css_get(&sk->sk_cgrp->memcg->css);
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return;
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}
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rcu_read_lock();
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memcg = mem_cgroup_from_task(current);
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cg_proto = sk->sk_prot->proto_cgroup(memcg);
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if (!mem_cgroup_is_root(memcg) &&
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memcg_proto_active(cg_proto) &&
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css_tryget_online(&memcg->css)) {
|
|
sk->sk_cgrp = cg_proto;
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(sock_update_memcg);
|
|
|
|
void sock_release_memcg(struct sock *sk)
|
|
{
|
|
if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
|
|
struct mem_cgroup *memcg;
|
|
WARN_ON(!sk->sk_cgrp->memcg);
|
|
memcg = sk->sk_cgrp->memcg;
|
|
css_put(&sk->sk_cgrp->memcg->css);
|
|
}
|
|
}
|
|
|
|
struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
|
|
{
|
|
if (!memcg || mem_cgroup_is_root(memcg))
|
|
return NULL;
|
|
|
|
return &memcg->tcp_mem;
|
|
}
|
|
EXPORT_SYMBOL(tcp_proto_cgroup);
|
|
|
|
static void disarm_sock_keys(struct mem_cgroup *memcg)
|
|
{
|
|
if (!memcg_proto_activated(&memcg->tcp_mem))
|
|
return;
|
|
static_key_slow_dec(&memcg_socket_limit_enabled);
|
|
}
|
|
#else
|
|
static void disarm_sock_keys(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
/*
|
|
* This will be the memcg's index in each cache's ->memcg_params->memcg_caches.
|
|
* The main reason for not using cgroup id for this:
|
|
* this works better in sparse environments, where we have a lot of memcgs,
|
|
* but only a few kmem-limited. Or also, if we have, for instance, 200
|
|
* memcgs, and none but the 200th is kmem-limited, we'd have to have a
|
|
* 200 entry array for that.
|
|
*
|
|
* The current size of the caches array is stored in
|
|
* memcg_limited_groups_array_size. It will double each time we have to
|
|
* increase it.
|
|
*/
|
|
static DEFINE_IDA(kmem_limited_groups);
|
|
int memcg_limited_groups_array_size;
|
|
|
|
/*
|
|
* MIN_SIZE is different than 1, because we would like to avoid going through
|
|
* the alloc/free process all the time. In a small machine, 4 kmem-limited
|
|
* cgroups is a reasonable guess. In the future, it could be a parameter or
|
|
* tunable, but that is strictly not necessary.
|
|
*
|
|
* MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
|
|
* this constant directly from cgroup, but it is understandable that this is
|
|
* better kept as an internal representation in cgroup.c. In any case, the
|
|
* cgrp_id space is not getting any smaller, and we don't have to necessarily
|
|
* increase ours as well if it increases.
|
|
*/
|
|
#define MEMCG_CACHES_MIN_SIZE 4
|
|
#define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
|
|
|
|
/*
|
|
* A lot of the calls to the cache allocation functions are expected to be
|
|
* inlined by the compiler. Since the calls to memcg_kmem_get_cache are
|
|
* conditional to this static branch, we'll have to allow modules that does
|
|
* kmem_cache_alloc and the such to see this symbol as well
|
|
*/
|
|
struct static_key memcg_kmem_enabled_key;
|
|
EXPORT_SYMBOL(memcg_kmem_enabled_key);
|
|
|
|
static void memcg_free_cache_id(int id);
|
|
|
|
static void disarm_kmem_keys(struct mem_cgroup *memcg)
|
|
{
|
|
if (memcg_kmem_is_active(memcg)) {
|
|
static_key_slow_dec(&memcg_kmem_enabled_key);
|
|
memcg_free_cache_id(memcg->kmemcg_id);
|
|
}
|
|
/*
|
|
* This check can't live in kmem destruction function,
|
|
* since the charges will outlive the cgroup
|
|
*/
|
|
WARN_ON(page_counter_read(&memcg->kmem));
|
|
}
|
|
#else
|
|
static void disarm_kmem_keys(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
#endif /* CONFIG_MEMCG_KMEM */
|
|
|
|
static void disarm_static_keys(struct mem_cgroup *memcg)
|
|
{
|
|
disarm_sock_keys(memcg);
|
|
disarm_kmem_keys(memcg);
|
|
}
|
|
|
|
static struct mem_cgroup_per_zone *
|
|
mem_cgroup_zone_zoneinfo(struct mem_cgroup *memcg, struct zone *zone)
|
|
{
|
|
int nid = zone_to_nid(zone);
|
|
int zid = zone_idx(zone);
|
|
|
|
return &memcg->nodeinfo[nid]->zoneinfo[zid];
|
|
}
|
|
|
|
struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg)
|
|
{
|
|
return &memcg->css;
|
|
}
|
|
|
|
static struct mem_cgroup_per_zone *
|
|
mem_cgroup_page_zoneinfo(struct mem_cgroup *memcg, struct page *page)
|
|
{
|
|
int nid = page_to_nid(page);
|
|
int zid = page_zonenum(page);
|
|
|
|
return &memcg->nodeinfo[nid]->zoneinfo[zid];
|
|
}
|
|
|
|
static struct mem_cgroup_tree_per_zone *
|
|
soft_limit_tree_node_zone(int nid, int zid)
|
|
{
|
|
return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
|
|
}
|
|
|
|
static struct mem_cgroup_tree_per_zone *
|
|
soft_limit_tree_from_page(struct page *page)
|
|
{
|
|
int nid = page_to_nid(page);
|
|
int zid = page_zonenum(page);
|
|
|
|
return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
|
|
}
|
|
|
|
static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone *mz,
|
|
struct mem_cgroup_tree_per_zone *mctz,
|
|
unsigned long new_usage_in_excess)
|
|
{
|
|
struct rb_node **p = &mctz->rb_root.rb_node;
|
|
struct rb_node *parent = NULL;
|
|
struct mem_cgroup_per_zone *mz_node;
|
|
|
|
if (mz->on_tree)
|
|
return;
|
|
|
|
mz->usage_in_excess = new_usage_in_excess;
|
|
if (!mz->usage_in_excess)
|
|
return;
|
|
while (*p) {
|
|
parent = *p;
|
|
mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
|
|
tree_node);
|
|
if (mz->usage_in_excess < mz_node->usage_in_excess)
|
|
p = &(*p)->rb_left;
|
|
/*
|
|
* We can't avoid mem cgroups that are over their soft
|
|
* limit by the same amount
|
|
*/
|
|
else if (mz->usage_in_excess >= mz_node->usage_in_excess)
|
|
p = &(*p)->rb_right;
|
|
}
|
|
rb_link_node(&mz->tree_node, parent, p);
|
|
rb_insert_color(&mz->tree_node, &mctz->rb_root);
|
|
mz->on_tree = true;
|
|
}
|
|
|
|
static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone *mz,
|
|
struct mem_cgroup_tree_per_zone *mctz)
|
|
{
|
|
if (!mz->on_tree)
|
|
return;
|
|
rb_erase(&mz->tree_node, &mctz->rb_root);
|
|
mz->on_tree = false;
|
|
}
|
|
|
|
static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone *mz,
|
|
struct mem_cgroup_tree_per_zone *mctz)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&mctz->lock, flags);
|
|
__mem_cgroup_remove_exceeded(mz, mctz);
|
|
spin_unlock_irqrestore(&mctz->lock, flags);
|
|
}
|
|
|
|
static unsigned long soft_limit_excess(struct mem_cgroup *memcg)
|
|
{
|
|
unsigned long nr_pages = page_counter_read(&memcg->memory);
|
|
unsigned long soft_limit = ACCESS_ONCE(memcg->soft_limit);
|
|
unsigned long excess = 0;
|
|
|
|
if (nr_pages > soft_limit)
|
|
excess = nr_pages - soft_limit;
|
|
|
|
return excess;
|
|
}
|
|
|
|
static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page)
|
|
{
|
|
unsigned long excess;
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct mem_cgroup_tree_per_zone *mctz;
|
|
|
|
mctz = soft_limit_tree_from_page(page);
|
|
/*
|
|
* Necessary to update all ancestors when hierarchy is used.
|
|
* because their event counter is not touched.
|
|
*/
|
|
for (; memcg; memcg = parent_mem_cgroup(memcg)) {
|
|
mz = mem_cgroup_page_zoneinfo(memcg, page);
|
|
excess = soft_limit_excess(memcg);
|
|
/*
|
|
* We have to update the tree if mz is on RB-tree or
|
|
* mem is over its softlimit.
|
|
*/
|
|
if (excess || mz->on_tree) {
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&mctz->lock, flags);
|
|
/* if on-tree, remove it */
|
|
if (mz->on_tree)
|
|
__mem_cgroup_remove_exceeded(mz, mctz);
|
|
/*
|
|
* Insert again. mz->usage_in_excess will be updated.
|
|
* If excess is 0, no tree ops.
|
|
*/
|
|
__mem_cgroup_insert_exceeded(mz, mctz, excess);
|
|
spin_unlock_irqrestore(&mctz->lock, flags);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup_tree_per_zone *mctz;
|
|
struct mem_cgroup_per_zone *mz;
|
|
int nid, zid;
|
|
|
|
for_each_node(nid) {
|
|
for (zid = 0; zid < MAX_NR_ZONES; zid++) {
|
|
mz = &memcg->nodeinfo[nid]->zoneinfo[zid];
|
|
mctz = soft_limit_tree_node_zone(nid, zid);
|
|
mem_cgroup_remove_exceeded(mz, mctz);
|
|
}
|
|
}
|
|
}
|
|
|
|
static struct mem_cgroup_per_zone *
|
|
__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
|
|
{
|
|
struct rb_node *rightmost = NULL;
|
|
struct mem_cgroup_per_zone *mz;
|
|
|
|
retry:
|
|
mz = NULL;
|
|
rightmost = rb_last(&mctz->rb_root);
|
|
if (!rightmost)
|
|
goto done; /* Nothing to reclaim from */
|
|
|
|
mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
|
|
/*
|
|
* Remove the node now but someone else can add it back,
|
|
* we will to add it back at the end of reclaim to its correct
|
|
* position in the tree.
|
|
*/
|
|
__mem_cgroup_remove_exceeded(mz, mctz);
|
|
if (!soft_limit_excess(mz->memcg) ||
|
|
!css_tryget_online(&mz->memcg->css))
|
|
goto retry;
|
|
done:
|
|
return mz;
|
|
}
|
|
|
|
static struct mem_cgroup_per_zone *
|
|
mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
|
|
spin_lock_irq(&mctz->lock);
|
|
mz = __mem_cgroup_largest_soft_limit_node(mctz);
|
|
spin_unlock_irq(&mctz->lock);
|
|
return mz;
|
|
}
|
|
|
|
/*
|
|
* Implementation Note: reading percpu statistics for memcg.
|
|
*
|
|
* Both of vmstat[] and percpu_counter has threshold and do periodic
|
|
* synchronization to implement "quick" read. There are trade-off between
|
|
* reading cost and precision of value. Then, we may have a chance to implement
|
|
* a periodic synchronizion of counter in memcg's counter.
|
|
*
|
|
* But this _read() function is used for user interface now. The user accounts
|
|
* memory usage by memory cgroup and he _always_ requires exact value because
|
|
* he accounts memory. Even if we provide quick-and-fuzzy read, we always
|
|
* have to visit all online cpus and make sum. So, for now, unnecessary
|
|
* synchronization is not implemented. (just implemented for cpu hotplug)
|
|
*
|
|
* If there are kernel internal actions which can make use of some not-exact
|
|
* value, and reading all cpu value can be performance bottleneck in some
|
|
* common workload, threashold and synchonization as vmstat[] should be
|
|
* implemented.
|
|
*/
|
|
static long mem_cgroup_read_stat(struct mem_cgroup *memcg,
|
|
enum mem_cgroup_stat_index idx)
|
|
{
|
|
long val = 0;
|
|
int cpu;
|
|
|
|
get_online_cpus();
|
|
for_each_online_cpu(cpu)
|
|
val += per_cpu(memcg->stat->count[idx], cpu);
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
spin_lock(&memcg->pcp_counter_lock);
|
|
val += memcg->nocpu_base.count[idx];
|
|
spin_unlock(&memcg->pcp_counter_lock);
|
|
#endif
|
|
put_online_cpus();
|
|
return val;
|
|
}
|
|
|
|
static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg,
|
|
enum mem_cgroup_events_index idx)
|
|
{
|
|
unsigned long val = 0;
|
|
int cpu;
|
|
|
|
get_online_cpus();
|
|
for_each_online_cpu(cpu)
|
|
val += per_cpu(memcg->stat->events[idx], cpu);
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
spin_lock(&memcg->pcp_counter_lock);
|
|
val += memcg->nocpu_base.events[idx];
|
|
spin_unlock(&memcg->pcp_counter_lock);
|
|
#endif
|
|
put_online_cpus();
|
|
return val;
|
|
}
|
|
|
|
static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
|
|
struct page *page,
|
|
int nr_pages)
|
|
{
|
|
/*
|
|
* Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
|
|
* counted as CACHE even if it's on ANON LRU.
|
|
*/
|
|
if (PageAnon(page))
|
|
__this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS],
|
|
nr_pages);
|
|
else
|
|
__this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE],
|
|
nr_pages);
|
|
|
|
if (PageTransHuge(page))
|
|
__this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE],
|
|
nr_pages);
|
|
|
|
/* pagein of a big page is an event. So, ignore page size */
|
|
if (nr_pages > 0)
|
|
__this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]);
|
|
else {
|
|
__this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]);
|
|
nr_pages = -nr_pages; /* for event */
|
|
}
|
|
|
|
__this_cpu_add(memcg->stat->nr_page_events, nr_pages);
|
|
}
|
|
|
|
unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
|
|
mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
|
|
return mz->lru_size[lru];
|
|
}
|
|
|
|
static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
|
|
int nid,
|
|
unsigned int lru_mask)
|
|
{
|
|
unsigned long nr = 0;
|
|
int zid;
|
|
|
|
VM_BUG_ON((unsigned)nid >= nr_node_ids);
|
|
|
|
for (zid = 0; zid < MAX_NR_ZONES; zid++) {
|
|
struct mem_cgroup_per_zone *mz;
|
|
enum lru_list lru;
|
|
|
|
for_each_lru(lru) {
|
|
if (!(BIT(lru) & lru_mask))
|
|
continue;
|
|
mz = &memcg->nodeinfo[nid]->zoneinfo[zid];
|
|
nr += mz->lru_size[lru];
|
|
}
|
|
}
|
|
return nr;
|
|
}
|
|
|
|
static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
|
|
unsigned int lru_mask)
|
|
{
|
|
unsigned long nr = 0;
|
|
int nid;
|
|
|
|
for_each_node_state(nid, N_MEMORY)
|
|
nr += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask);
|
|
return nr;
|
|
}
|
|
|
|
static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
|
|
enum mem_cgroup_events_target target)
|
|
{
|
|
unsigned long val, next;
|
|
|
|
val = __this_cpu_read(memcg->stat->nr_page_events);
|
|
next = __this_cpu_read(memcg->stat->targets[target]);
|
|
/* from time_after() in jiffies.h */
|
|
if ((long)next - (long)val < 0) {
|
|
switch (target) {
|
|
case MEM_CGROUP_TARGET_THRESH:
|
|
next = val + THRESHOLDS_EVENTS_TARGET;
|
|
break;
|
|
case MEM_CGROUP_TARGET_SOFTLIMIT:
|
|
next = val + SOFTLIMIT_EVENTS_TARGET;
|
|
break;
|
|
case MEM_CGROUP_TARGET_NUMAINFO:
|
|
next = val + NUMAINFO_EVENTS_TARGET;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
__this_cpu_write(memcg->stat->targets[target], next);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Check events in order.
|
|
*
|
|
*/
|
|
static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
|
|
{
|
|
/* threshold event is triggered in finer grain than soft limit */
|
|
if (unlikely(mem_cgroup_event_ratelimit(memcg,
|
|
MEM_CGROUP_TARGET_THRESH))) {
|
|
bool do_softlimit;
|
|
bool do_numainfo __maybe_unused;
|
|
|
|
do_softlimit = mem_cgroup_event_ratelimit(memcg,
|
|
MEM_CGROUP_TARGET_SOFTLIMIT);
|
|
#if MAX_NUMNODES > 1
|
|
do_numainfo = mem_cgroup_event_ratelimit(memcg,
|
|
MEM_CGROUP_TARGET_NUMAINFO);
|
|
#endif
|
|
mem_cgroup_threshold(memcg);
|
|
if (unlikely(do_softlimit))
|
|
mem_cgroup_update_tree(memcg, page);
|
|
#if MAX_NUMNODES > 1
|
|
if (unlikely(do_numainfo))
|
|
atomic_inc(&memcg->numainfo_events);
|
|
#endif
|
|
}
|
|
}
|
|
|
|
struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
|
|
{
|
|
/*
|
|
* mm_update_next_owner() may clear mm->owner to NULL
|
|
* if it races with swapoff, page migration, etc.
|
|
* So this can be called with p == NULL.
|
|
*/
|
|
if (unlikely(!p))
|
|
return NULL;
|
|
|
|
return mem_cgroup_from_css(task_css(p, memory_cgrp_id));
|
|
}
|
|
|
|
static struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
|
|
rcu_read_lock();
|
|
do {
|
|
/*
|
|
* Page cache insertions can happen withou an
|
|
* actual mm context, e.g. during disk probing
|
|
* on boot, loopback IO, acct() writes etc.
|
|
*/
|
|
if (unlikely(!mm))
|
|
memcg = root_mem_cgroup;
|
|
else {
|
|
memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
|
|
if (unlikely(!memcg))
|
|
memcg = root_mem_cgroup;
|
|
}
|
|
} while (!css_tryget_online(&memcg->css));
|
|
rcu_read_unlock();
|
|
return memcg;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_iter - iterate over memory cgroup hierarchy
|
|
* @root: hierarchy root
|
|
* @prev: previously returned memcg, NULL on first invocation
|
|
* @reclaim: cookie for shared reclaim walks, NULL for full walks
|
|
*
|
|
* Returns references to children of the hierarchy below @root, or
|
|
* @root itself, or %NULL after a full round-trip.
|
|
*
|
|
* Caller must pass the return value in @prev on subsequent
|
|
* invocations for reference counting, or use mem_cgroup_iter_break()
|
|
* to cancel a hierarchy walk before the round-trip is complete.
|
|
*
|
|
* Reclaimers can specify a zone and a priority level in @reclaim to
|
|
* divide up the memcgs in the hierarchy among all concurrent
|
|
* reclaimers operating on the same zone and priority.
|
|
*/
|
|
struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
|
|
struct mem_cgroup *prev,
|
|
struct mem_cgroup_reclaim_cookie *reclaim)
|
|
{
|
|
struct reclaim_iter *uninitialized_var(iter);
|
|
struct cgroup_subsys_state *css = NULL;
|
|
struct mem_cgroup *memcg = NULL;
|
|
struct mem_cgroup *pos = NULL;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return NULL;
|
|
|
|
if (!root)
|
|
root = root_mem_cgroup;
|
|
|
|
if (prev && !reclaim)
|
|
pos = prev;
|
|
|
|
if (!root->use_hierarchy && root != root_mem_cgroup) {
|
|
if (prev)
|
|
goto out;
|
|
return root;
|
|
}
|
|
|
|
rcu_read_lock();
|
|
|
|
if (reclaim) {
|
|
struct mem_cgroup_per_zone *mz;
|
|
|
|
mz = mem_cgroup_zone_zoneinfo(root, reclaim->zone);
|
|
iter = &mz->iter[reclaim->priority];
|
|
|
|
if (prev && reclaim->generation != iter->generation)
|
|
goto out_unlock;
|
|
|
|
do {
|
|
pos = ACCESS_ONCE(iter->position);
|
|
/*
|
|
* A racing update may change the position and
|
|
* put the last reference, hence css_tryget(),
|
|
* or retry to see the updated position.
|
|
*/
|
|
} while (pos && !css_tryget(&pos->css));
|
|
}
|
|
|
|
if (pos)
|
|
css = &pos->css;
|
|
|
|
for (;;) {
|
|
css = css_next_descendant_pre(css, &root->css);
|
|
if (!css) {
|
|
/*
|
|
* Reclaimers share the hierarchy walk, and a
|
|
* new one might jump in right at the end of
|
|
* the hierarchy - make sure they see at least
|
|
* one group and restart from the beginning.
|
|
*/
|
|
if (!prev)
|
|
continue;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Verify the css and acquire a reference. The root
|
|
* is provided by the caller, so we know it's alive
|
|
* and kicking, and don't take an extra reference.
|
|
*/
|
|
memcg = mem_cgroup_from_css(css);
|
|
|
|
if (css == &root->css)
|
|
break;
|
|
|
|
if (css_tryget(css)) {
|
|
/*
|
|
* Make sure the memcg is initialized:
|
|
* mem_cgroup_css_online() orders the the
|
|
* initialization against setting the flag.
|
|
*/
|
|
if (smp_load_acquire(&memcg->initialized))
|
|
break;
|
|
|
|
css_put(css);
|
|
}
|
|
|
|
memcg = NULL;
|
|
}
|
|
|
|
if (reclaim) {
|
|
if (cmpxchg(&iter->position, pos, memcg) == pos) {
|
|
if (memcg)
|
|
css_get(&memcg->css);
|
|
if (pos)
|
|
css_put(&pos->css);
|
|
}
|
|
|
|
/*
|
|
* pairs with css_tryget when dereferencing iter->position
|
|
* above.
|
|
*/
|
|
if (pos)
|
|
css_put(&pos->css);
|
|
|
|
if (!memcg)
|
|
iter->generation++;
|
|
else if (!prev)
|
|
reclaim->generation = iter->generation;
|
|
}
|
|
|
|
out_unlock:
|
|
rcu_read_unlock();
|
|
out:
|
|
if (prev && prev != root)
|
|
css_put(&prev->css);
|
|
|
|
return memcg;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_iter_break - abort a hierarchy walk prematurely
|
|
* @root: hierarchy root
|
|
* @prev: last visited hierarchy member as returned by mem_cgroup_iter()
|
|
*/
|
|
void mem_cgroup_iter_break(struct mem_cgroup *root,
|
|
struct mem_cgroup *prev)
|
|
{
|
|
if (!root)
|
|
root = root_mem_cgroup;
|
|
if (prev && prev != root)
|
|
css_put(&prev->css);
|
|
}
|
|
|
|
/*
|
|
* Iteration constructs for visiting all cgroups (under a tree). If
|
|
* loops are exited prematurely (break), mem_cgroup_iter_break() must
|
|
* be used for reference counting.
|
|
*/
|
|
#define for_each_mem_cgroup_tree(iter, root) \
|
|
for (iter = mem_cgroup_iter(root, NULL, NULL); \
|
|
iter != NULL; \
|
|
iter = mem_cgroup_iter(root, iter, NULL))
|
|
|
|
#define for_each_mem_cgroup(iter) \
|
|
for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
|
|
iter != NULL; \
|
|
iter = mem_cgroup_iter(NULL, iter, NULL))
|
|
|
|
void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
|
|
if (unlikely(!memcg))
|
|
goto out;
|
|
|
|
switch (idx) {
|
|
case PGFAULT:
|
|
this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]);
|
|
break;
|
|
case PGMAJFAULT:
|
|
this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]);
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
out:
|
|
rcu_read_unlock();
|
|
}
|
|
EXPORT_SYMBOL(__mem_cgroup_count_vm_event);
|
|
|
|
/**
|
|
* mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
|
|
* @zone: zone of the wanted lruvec
|
|
* @memcg: memcg of the wanted lruvec
|
|
*
|
|
* Returns the lru list vector holding pages for the given @zone and
|
|
* @mem. This can be the global zone lruvec, if the memory controller
|
|
* is disabled.
|
|
*/
|
|
struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
|
|
struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct lruvec *lruvec;
|
|
|
|
if (mem_cgroup_disabled()) {
|
|
lruvec = &zone->lruvec;
|
|
goto out;
|
|
}
|
|
|
|
mz = mem_cgroup_zone_zoneinfo(memcg, zone);
|
|
lruvec = &mz->lruvec;
|
|
out:
|
|
/*
|
|
* Since a node can be onlined after the mem_cgroup was created,
|
|
* we have to be prepared to initialize lruvec->zone here;
|
|
* and if offlined then reonlined, we need to reinitialize it.
|
|
*/
|
|
if (unlikely(lruvec->zone != zone))
|
|
lruvec->zone = zone;
|
|
return lruvec;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
|
|
* @page: the page
|
|
* @zone: zone of the page
|
|
*
|
|
* This function is only safe when following the LRU page isolation
|
|
* and putback protocol: the LRU lock must be held, and the page must
|
|
* either be PageLRU() or the caller must have isolated/allocated it.
|
|
*/
|
|
struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct mem_cgroup *memcg;
|
|
struct lruvec *lruvec;
|
|
|
|
if (mem_cgroup_disabled()) {
|
|
lruvec = &zone->lruvec;
|
|
goto out;
|
|
}
|
|
|
|
memcg = page->mem_cgroup;
|
|
/*
|
|
* Swapcache readahead pages are added to the LRU - and
|
|
* possibly migrated - before they are charged.
|
|
*/
|
|
if (!memcg)
|
|
memcg = root_mem_cgroup;
|
|
|
|
mz = mem_cgroup_page_zoneinfo(memcg, page);
|
|
lruvec = &mz->lruvec;
|
|
out:
|
|
/*
|
|
* Since a node can be onlined after the mem_cgroup was created,
|
|
* we have to be prepared to initialize lruvec->zone here;
|
|
* and if offlined then reonlined, we need to reinitialize it.
|
|
*/
|
|
if (unlikely(lruvec->zone != zone))
|
|
lruvec->zone = zone;
|
|
return lruvec;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_update_lru_size - account for adding or removing an lru page
|
|
* @lruvec: mem_cgroup per zone lru vector
|
|
* @lru: index of lru list the page is sitting on
|
|
* @nr_pages: positive when adding or negative when removing
|
|
*
|
|
* This function must be called when a page is added to or removed from an
|
|
* lru list.
|
|
*/
|
|
void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
|
|
int nr_pages)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
unsigned long *lru_size;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
|
|
lru_size = mz->lru_size + lru;
|
|
*lru_size += nr_pages;
|
|
VM_BUG_ON((long)(*lru_size) < 0);
|
|
}
|
|
|
|
bool mem_cgroup_is_descendant(struct mem_cgroup *memcg, struct mem_cgroup *root)
|
|
{
|
|
if (root == memcg)
|
|
return true;
|
|
if (!root->use_hierarchy)
|
|
return false;
|
|
return cgroup_is_descendant(memcg->css.cgroup, root->css.cgroup);
|
|
}
|
|
|
|
bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *task_memcg;
|
|
struct task_struct *p;
|
|
bool ret;
|
|
|
|
p = find_lock_task_mm(task);
|
|
if (p) {
|
|
task_memcg = get_mem_cgroup_from_mm(p->mm);
|
|
task_unlock(p);
|
|
} else {
|
|
/*
|
|
* All threads may have already detached their mm's, but the oom
|
|
* killer still needs to detect if they have already been oom
|
|
* killed to prevent needlessly killing additional tasks.
|
|
*/
|
|
rcu_read_lock();
|
|
task_memcg = mem_cgroup_from_task(task);
|
|
css_get(&task_memcg->css);
|
|
rcu_read_unlock();
|
|
}
|
|
ret = mem_cgroup_is_descendant(task_memcg, memcg);
|
|
css_put(&task_memcg->css);
|
|
return ret;
|
|
}
|
|
|
|
int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
|
|
{
|
|
unsigned long inactive_ratio;
|
|
unsigned long inactive;
|
|
unsigned long active;
|
|
unsigned long gb;
|
|
|
|
inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON);
|
|
active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON);
|
|
|
|
gb = (inactive + active) >> (30 - PAGE_SHIFT);
|
|
if (gb)
|
|
inactive_ratio = int_sqrt(10 * gb);
|
|
else
|
|
inactive_ratio = 1;
|
|
|
|
return inactive * inactive_ratio < active;
|
|
}
|
|
|
|
#define mem_cgroup_from_counter(counter, member) \
|
|
container_of(counter, struct mem_cgroup, member)
|
|
|
|
/**
|
|
* mem_cgroup_margin - calculate chargeable space of a memory cgroup
|
|
* @memcg: the memory cgroup
|
|
*
|
|
* Returns the maximum amount of memory @mem can be charged with, in
|
|
* pages.
|
|
*/
|
|
static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg)
|
|
{
|
|
unsigned long margin = 0;
|
|
unsigned long count;
|
|
unsigned long limit;
|
|
|
|
count = page_counter_read(&memcg->memory);
|
|
limit = ACCESS_ONCE(memcg->memory.limit);
|
|
if (count < limit)
|
|
margin = limit - count;
|
|
|
|
if (do_swap_account) {
|
|
count = page_counter_read(&memcg->memsw);
|
|
limit = ACCESS_ONCE(memcg->memsw.limit);
|
|
if (count <= limit)
|
|
margin = min(margin, limit - count);
|
|
}
|
|
|
|
return margin;
|
|
}
|
|
|
|
int mem_cgroup_swappiness(struct mem_cgroup *memcg)
|
|
{
|
|
/* root ? */
|
|
if (mem_cgroup_disabled() || !memcg->css.parent)
|
|
return vm_swappiness;
|
|
|
|
return memcg->swappiness;
|
|
}
|
|
|
|
/*
|
|
* A routine for checking "mem" is under move_account() or not.
|
|
*
|
|
* Checking a cgroup is mc.from or mc.to or under hierarchy of
|
|
* moving cgroups. This is for waiting at high-memory pressure
|
|
* caused by "move".
|
|
*/
|
|
static bool mem_cgroup_under_move(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *from;
|
|
struct mem_cgroup *to;
|
|
bool ret = false;
|
|
/*
|
|
* Unlike task_move routines, we access mc.to, mc.from not under
|
|
* mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
|
|
*/
|
|
spin_lock(&mc.lock);
|
|
from = mc.from;
|
|
to = mc.to;
|
|
if (!from)
|
|
goto unlock;
|
|
|
|
ret = mem_cgroup_is_descendant(from, memcg) ||
|
|
mem_cgroup_is_descendant(to, memcg);
|
|
unlock:
|
|
spin_unlock(&mc.lock);
|
|
return ret;
|
|
}
|
|
|
|
static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg)
|
|
{
|
|
if (mc.moving_task && current != mc.moving_task) {
|
|
if (mem_cgroup_under_move(memcg)) {
|
|
DEFINE_WAIT(wait);
|
|
prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
|
|
/* moving charge context might have finished. */
|
|
if (mc.moving_task)
|
|
schedule();
|
|
finish_wait(&mc.waitq, &wait);
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
#define K(x) ((x) << (PAGE_SHIFT-10))
|
|
/**
|
|
* mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
|
|
* @memcg: The memory cgroup that went over limit
|
|
* @p: Task that is going to be killed
|
|
*
|
|
* NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
|
|
* enabled
|
|
*/
|
|
void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
|
|
{
|
|
/* oom_info_lock ensures that parallel ooms do not interleave */
|
|
static DEFINE_MUTEX(oom_info_lock);
|
|
struct mem_cgroup *iter;
|
|
unsigned int i;
|
|
|
|
if (!p)
|
|
return;
|
|
|
|
mutex_lock(&oom_info_lock);
|
|
rcu_read_lock();
|
|
|
|
pr_info("Task in ");
|
|
pr_cont_cgroup_path(task_cgroup(p, memory_cgrp_id));
|
|
pr_info(" killed as a result of limit of ");
|
|
pr_cont_cgroup_path(memcg->css.cgroup);
|
|
pr_info("\n");
|
|
|
|
rcu_read_unlock();
|
|
|
|
pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
|
|
K((u64)page_counter_read(&memcg->memory)),
|
|
K((u64)memcg->memory.limit), memcg->memory.failcnt);
|
|
pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
|
|
K((u64)page_counter_read(&memcg->memsw)),
|
|
K((u64)memcg->memsw.limit), memcg->memsw.failcnt);
|
|
pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
|
|
K((u64)page_counter_read(&memcg->kmem)),
|
|
K((u64)memcg->kmem.limit), memcg->kmem.failcnt);
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg) {
|
|
pr_info("Memory cgroup stats for ");
|
|
pr_cont_cgroup_path(iter->css.cgroup);
|
|
pr_cont(":");
|
|
|
|
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
|
|
if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
|
|
continue;
|
|
pr_cont(" %s:%ldKB", mem_cgroup_stat_names[i],
|
|
K(mem_cgroup_read_stat(iter, i)));
|
|
}
|
|
|
|
for (i = 0; i < NR_LRU_LISTS; i++)
|
|
pr_cont(" %s:%luKB", mem_cgroup_lru_names[i],
|
|
K(mem_cgroup_nr_lru_pages(iter, BIT(i))));
|
|
|
|
pr_cont("\n");
|
|
}
|
|
mutex_unlock(&oom_info_lock);
|
|
}
|
|
|
|
/*
|
|
* This function returns the number of memcg under hierarchy tree. Returns
|
|
* 1(self count) if no children.
|
|
*/
|
|
static int mem_cgroup_count_children(struct mem_cgroup *memcg)
|
|
{
|
|
int num = 0;
|
|
struct mem_cgroup *iter;
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
num++;
|
|
return num;
|
|
}
|
|
|
|
/*
|
|
* Return the memory (and swap, if configured) limit for a memcg.
|
|
*/
|
|
static unsigned long mem_cgroup_get_limit(struct mem_cgroup *memcg)
|
|
{
|
|
unsigned long limit;
|
|
|
|
limit = memcg->memory.limit;
|
|
if (mem_cgroup_swappiness(memcg)) {
|
|
unsigned long memsw_limit;
|
|
|
|
memsw_limit = memcg->memsw.limit;
|
|
limit = min(limit + total_swap_pages, memsw_limit);
|
|
}
|
|
return limit;
|
|
}
|
|
|
|
static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
|
|
int order)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
unsigned long chosen_points = 0;
|
|
unsigned long totalpages;
|
|
unsigned int points = 0;
|
|
struct task_struct *chosen = NULL;
|
|
|
|
/*
|
|
* If current has a pending SIGKILL or is exiting, then automatically
|
|
* select it. The goal is to allow it to allocate so that it may
|
|
* quickly exit and free its memory.
|
|
*/
|
|
if (fatal_signal_pending(current) || task_will_free_mem(current)) {
|
|
set_thread_flag(TIF_MEMDIE);
|
|
return;
|
|
}
|
|
|
|
check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL);
|
|
totalpages = mem_cgroup_get_limit(memcg) ? : 1;
|
|
for_each_mem_cgroup_tree(iter, memcg) {
|
|
struct css_task_iter it;
|
|
struct task_struct *task;
|
|
|
|
css_task_iter_start(&iter->css, &it);
|
|
while ((task = css_task_iter_next(&it))) {
|
|
switch (oom_scan_process_thread(task, totalpages, NULL,
|
|
false)) {
|
|
case OOM_SCAN_SELECT:
|
|
if (chosen)
|
|
put_task_struct(chosen);
|
|
chosen = task;
|
|
chosen_points = ULONG_MAX;
|
|
get_task_struct(chosen);
|
|
/* fall through */
|
|
case OOM_SCAN_CONTINUE:
|
|
continue;
|
|
case OOM_SCAN_ABORT:
|
|
css_task_iter_end(&it);
|
|
mem_cgroup_iter_break(memcg, iter);
|
|
if (chosen)
|
|
put_task_struct(chosen);
|
|
return;
|
|
case OOM_SCAN_OK:
|
|
break;
|
|
};
|
|
points = oom_badness(task, memcg, NULL, totalpages);
|
|
if (!points || points < chosen_points)
|
|
continue;
|
|
/* Prefer thread group leaders for display purposes */
|
|
if (points == chosen_points &&
|
|
thread_group_leader(chosen))
|
|
continue;
|
|
|
|
if (chosen)
|
|
put_task_struct(chosen);
|
|
chosen = task;
|
|
chosen_points = points;
|
|
get_task_struct(chosen);
|
|
}
|
|
css_task_iter_end(&it);
|
|
}
|
|
|
|
if (!chosen)
|
|
return;
|
|
points = chosen_points * 1000 / totalpages;
|
|
oom_kill_process(chosen, gfp_mask, order, points, totalpages, memcg,
|
|
NULL, "Memory cgroup out of memory");
|
|
}
|
|
|
|
#if MAX_NUMNODES > 1
|
|
|
|
/**
|
|
* test_mem_cgroup_node_reclaimable
|
|
* @memcg: the target memcg
|
|
* @nid: the node ID to be checked.
|
|
* @noswap : specify true here if the user wants flle only information.
|
|
*
|
|
* This function returns whether the specified memcg contains any
|
|
* reclaimable pages on a node. Returns true if there are any reclaimable
|
|
* pages in the node.
|
|
*/
|
|
static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg,
|
|
int nid, bool noswap)
|
|
{
|
|
if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE))
|
|
return true;
|
|
if (noswap || !total_swap_pages)
|
|
return false;
|
|
if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON))
|
|
return true;
|
|
return false;
|
|
|
|
}
|
|
|
|
/*
|
|
* Always updating the nodemask is not very good - even if we have an empty
|
|
* list or the wrong list here, we can start from some node and traverse all
|
|
* nodes based on the zonelist. So update the list loosely once per 10 secs.
|
|
*
|
|
*/
|
|
static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg)
|
|
{
|
|
int nid;
|
|
/*
|
|
* numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
|
|
* pagein/pageout changes since the last update.
|
|
*/
|
|
if (!atomic_read(&memcg->numainfo_events))
|
|
return;
|
|
if (atomic_inc_return(&memcg->numainfo_updating) > 1)
|
|
return;
|
|
|
|
/* make a nodemask where this memcg uses memory from */
|
|
memcg->scan_nodes = node_states[N_MEMORY];
|
|
|
|
for_each_node_mask(nid, node_states[N_MEMORY]) {
|
|
|
|
if (!test_mem_cgroup_node_reclaimable(memcg, nid, false))
|
|
node_clear(nid, memcg->scan_nodes);
|
|
}
|
|
|
|
atomic_set(&memcg->numainfo_events, 0);
|
|
atomic_set(&memcg->numainfo_updating, 0);
|
|
}
|
|
|
|
/*
|
|
* Selecting a node where we start reclaim from. Because what we need is just
|
|
* reducing usage counter, start from anywhere is O,K. Considering
|
|
* memory reclaim from current node, there are pros. and cons.
|
|
*
|
|
* Freeing memory from current node means freeing memory from a node which
|
|
* we'll use or we've used. So, it may make LRU bad. And if several threads
|
|
* hit limits, it will see a contention on a node. But freeing from remote
|
|
* node means more costs for memory reclaim because of memory latency.
|
|
*
|
|
* Now, we use round-robin. Better algorithm is welcomed.
|
|
*/
|
|
int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
|
|
{
|
|
int node;
|
|
|
|
mem_cgroup_may_update_nodemask(memcg);
|
|
node = memcg->last_scanned_node;
|
|
|
|
node = next_node(node, memcg->scan_nodes);
|
|
if (node == MAX_NUMNODES)
|
|
node = first_node(memcg->scan_nodes);
|
|
/*
|
|
* We call this when we hit limit, not when pages are added to LRU.
|
|
* No LRU may hold pages because all pages are UNEVICTABLE or
|
|
* memcg is too small and all pages are not on LRU. In that case,
|
|
* we use curret node.
|
|
*/
|
|
if (unlikely(node == MAX_NUMNODES))
|
|
node = numa_node_id();
|
|
|
|
memcg->last_scanned_node = node;
|
|
return node;
|
|
}
|
|
#else
|
|
int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
|
|
struct zone *zone,
|
|
gfp_t gfp_mask,
|
|
unsigned long *total_scanned)
|
|
{
|
|
struct mem_cgroup *victim = NULL;
|
|
int total = 0;
|
|
int loop = 0;
|
|
unsigned long excess;
|
|
unsigned long nr_scanned;
|
|
struct mem_cgroup_reclaim_cookie reclaim = {
|
|
.zone = zone,
|
|
.priority = 0,
|
|
};
|
|
|
|
excess = soft_limit_excess(root_memcg);
|
|
|
|
while (1) {
|
|
victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
|
|
if (!victim) {
|
|
loop++;
|
|
if (loop >= 2) {
|
|
/*
|
|
* If we have not been able to reclaim
|
|
* anything, it might because there are
|
|
* no reclaimable pages under this hierarchy
|
|
*/
|
|
if (!total)
|
|
break;
|
|
/*
|
|
* We want to do more targeted reclaim.
|
|
* excess >> 2 is not to excessive so as to
|
|
* reclaim too much, nor too less that we keep
|
|
* coming back to reclaim from this cgroup
|
|
*/
|
|
if (total >= (excess >> 2) ||
|
|
(loop > MEM_CGROUP_MAX_RECLAIM_LOOPS))
|
|
break;
|
|
}
|
|
continue;
|
|
}
|
|
total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false,
|
|
zone, &nr_scanned);
|
|
*total_scanned += nr_scanned;
|
|
if (!soft_limit_excess(root_memcg))
|
|
break;
|
|
}
|
|
mem_cgroup_iter_break(root_memcg, victim);
|
|
return total;
|
|
}
|
|
|
|
#ifdef CONFIG_LOCKDEP
|
|
static struct lockdep_map memcg_oom_lock_dep_map = {
|
|
.name = "memcg_oom_lock",
|
|
};
|
|
#endif
|
|
|
|
static DEFINE_SPINLOCK(memcg_oom_lock);
|
|
|
|
/*
|
|
* Check OOM-Killer is already running under our hierarchy.
|
|
* If someone is running, return false.
|
|
*/
|
|
static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter, *failed = NULL;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg) {
|
|
if (iter->oom_lock) {
|
|
/*
|
|
* this subtree of our hierarchy is already locked
|
|
* so we cannot give a lock.
|
|
*/
|
|
failed = iter;
|
|
mem_cgroup_iter_break(memcg, iter);
|
|
break;
|
|
} else
|
|
iter->oom_lock = true;
|
|
}
|
|
|
|
if (failed) {
|
|
/*
|
|
* OK, we failed to lock the whole subtree so we have
|
|
* to clean up what we set up to the failing subtree
|
|
*/
|
|
for_each_mem_cgroup_tree(iter, memcg) {
|
|
if (iter == failed) {
|
|
mem_cgroup_iter_break(memcg, iter);
|
|
break;
|
|
}
|
|
iter->oom_lock = false;
|
|
}
|
|
} else
|
|
mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_);
|
|
|
|
spin_unlock(&memcg_oom_lock);
|
|
|
|
return !failed;
|
|
}
|
|
|
|
static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
mutex_release(&memcg_oom_lock_dep_map, 1, _RET_IP_);
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
iter->oom_lock = false;
|
|
spin_unlock(&memcg_oom_lock);
|
|
}
|
|
|
|
static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
atomic_inc(&iter->under_oom);
|
|
}
|
|
|
|
static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
/*
|
|
* When a new child is created while the hierarchy is under oom,
|
|
* mem_cgroup_oom_lock() may not be called. We have to use
|
|
* atomic_add_unless() here.
|
|
*/
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
atomic_add_unless(&iter->under_oom, -1, 0);
|
|
}
|
|
|
|
static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
|
|
|
|
struct oom_wait_info {
|
|
struct mem_cgroup *memcg;
|
|
wait_queue_t wait;
|
|
};
|
|
|
|
static int memcg_oom_wake_function(wait_queue_t *wait,
|
|
unsigned mode, int sync, void *arg)
|
|
{
|
|
struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg;
|
|
struct mem_cgroup *oom_wait_memcg;
|
|
struct oom_wait_info *oom_wait_info;
|
|
|
|
oom_wait_info = container_of(wait, struct oom_wait_info, wait);
|
|
oom_wait_memcg = oom_wait_info->memcg;
|
|
|
|
if (!mem_cgroup_is_descendant(wake_memcg, oom_wait_memcg) &&
|
|
!mem_cgroup_is_descendant(oom_wait_memcg, wake_memcg))
|
|
return 0;
|
|
return autoremove_wake_function(wait, mode, sync, arg);
|
|
}
|
|
|
|
static void memcg_wakeup_oom(struct mem_cgroup *memcg)
|
|
{
|
|
atomic_inc(&memcg->oom_wakeups);
|
|
/* for filtering, pass "memcg" as argument. */
|
|
__wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg);
|
|
}
|
|
|
|
static void memcg_oom_recover(struct mem_cgroup *memcg)
|
|
{
|
|
if (memcg && atomic_read(&memcg->under_oom))
|
|
memcg_wakeup_oom(memcg);
|
|
}
|
|
|
|
static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order)
|
|
{
|
|
if (!current->memcg_oom.may_oom)
|
|
return;
|
|
/*
|
|
* We are in the middle of the charge context here, so we
|
|
* don't want to block when potentially sitting on a callstack
|
|
* that holds all kinds of filesystem and mm locks.
|
|
*
|
|
* Also, the caller may handle a failed allocation gracefully
|
|
* (like optional page cache readahead) and so an OOM killer
|
|
* invocation might not even be necessary.
|
|
*
|
|
* That's why we don't do anything here except remember the
|
|
* OOM context and then deal with it at the end of the page
|
|
* fault when the stack is unwound, the locks are released,
|
|
* and when we know whether the fault was overall successful.
|
|
*/
|
|
css_get(&memcg->css);
|
|
current->memcg_oom.memcg = memcg;
|
|
current->memcg_oom.gfp_mask = mask;
|
|
current->memcg_oom.order = order;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_oom_synchronize - complete memcg OOM handling
|
|
* @handle: actually kill/wait or just clean up the OOM state
|
|
*
|
|
* This has to be called at the end of a page fault if the memcg OOM
|
|
* handler was enabled.
|
|
*
|
|
* Memcg supports userspace OOM handling where failed allocations must
|
|
* sleep on a waitqueue until the userspace task resolves the
|
|
* situation. Sleeping directly in the charge context with all kinds
|
|
* of locks held is not a good idea, instead we remember an OOM state
|
|
* in the task and mem_cgroup_oom_synchronize() has to be called at
|
|
* the end of the page fault to complete the OOM handling.
|
|
*
|
|
* Returns %true if an ongoing memcg OOM situation was detected and
|
|
* completed, %false otherwise.
|
|
*/
|
|
bool mem_cgroup_oom_synchronize(bool handle)
|
|
{
|
|
struct mem_cgroup *memcg = current->memcg_oom.memcg;
|
|
struct oom_wait_info owait;
|
|
bool locked;
|
|
|
|
/* OOM is global, do not handle */
|
|
if (!memcg)
|
|
return false;
|
|
|
|
if (!handle)
|
|
goto cleanup;
|
|
|
|
owait.memcg = memcg;
|
|
owait.wait.flags = 0;
|
|
owait.wait.func = memcg_oom_wake_function;
|
|
owait.wait.private = current;
|
|
INIT_LIST_HEAD(&owait.wait.task_list);
|
|
|
|
prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
|
|
mem_cgroup_mark_under_oom(memcg);
|
|
|
|
locked = mem_cgroup_oom_trylock(memcg);
|
|
|
|
if (locked)
|
|
mem_cgroup_oom_notify(memcg);
|
|
|
|
if (locked && !memcg->oom_kill_disable) {
|
|
mem_cgroup_unmark_under_oom(memcg);
|
|
finish_wait(&memcg_oom_waitq, &owait.wait);
|
|
mem_cgroup_out_of_memory(memcg, current->memcg_oom.gfp_mask,
|
|
current->memcg_oom.order);
|
|
} else {
|
|
schedule();
|
|
mem_cgroup_unmark_under_oom(memcg);
|
|
finish_wait(&memcg_oom_waitq, &owait.wait);
|
|
}
|
|
|
|
if (locked) {
|
|
mem_cgroup_oom_unlock(memcg);
|
|
/*
|
|
* There is no guarantee that an OOM-lock contender
|
|
* sees the wakeups triggered by the OOM kill
|
|
* uncharges. Wake any sleepers explicitely.
|
|
*/
|
|
memcg_oom_recover(memcg);
|
|
}
|
|
cleanup:
|
|
current->memcg_oom.memcg = NULL;
|
|
css_put(&memcg->css);
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_begin_page_stat - begin a page state statistics transaction
|
|
* @page: page that is going to change accounted state
|
|
* @locked: &memcg->move_lock slowpath was taken
|
|
* @flags: IRQ-state flags for &memcg->move_lock
|
|
*
|
|
* This function must mark the beginning of an accounted page state
|
|
* change to prevent double accounting when the page is concurrently
|
|
* being moved to another memcg:
|
|
*
|
|
* memcg = mem_cgroup_begin_page_stat(page, &locked, &flags);
|
|
* if (TestClearPageState(page))
|
|
* mem_cgroup_update_page_stat(memcg, state, -1);
|
|
* mem_cgroup_end_page_stat(memcg, locked, flags);
|
|
*
|
|
* The RCU lock is held throughout the transaction. The fast path can
|
|
* get away without acquiring the memcg->move_lock (@locked is false)
|
|
* because page moving starts with an RCU grace period.
|
|
*
|
|
* The RCU lock also protects the memcg from being freed when the page
|
|
* state that is going to change is the only thing preventing the page
|
|
* from being uncharged. E.g. end-writeback clearing PageWriteback(),
|
|
* which allows migration to go ahead and uncharge the page before the
|
|
* account transaction might be complete.
|
|
*/
|
|
struct mem_cgroup *mem_cgroup_begin_page_stat(struct page *page,
|
|
bool *locked,
|
|
unsigned long *flags)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
|
|
rcu_read_lock();
|
|
|
|
if (mem_cgroup_disabled())
|
|
return NULL;
|
|
again:
|
|
memcg = page->mem_cgroup;
|
|
if (unlikely(!memcg))
|
|
return NULL;
|
|
|
|
*locked = false;
|
|
if (atomic_read(&memcg->moving_account) <= 0)
|
|
return memcg;
|
|
|
|
spin_lock_irqsave(&memcg->move_lock, *flags);
|
|
if (memcg != page->mem_cgroup) {
|
|
spin_unlock_irqrestore(&memcg->move_lock, *flags);
|
|
goto again;
|
|
}
|
|
*locked = true;
|
|
|
|
return memcg;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_end_page_stat - finish a page state statistics transaction
|
|
* @memcg: the memcg that was accounted against
|
|
* @locked: value received from mem_cgroup_begin_page_stat()
|
|
* @flags: value received from mem_cgroup_begin_page_stat()
|
|
*/
|
|
void mem_cgroup_end_page_stat(struct mem_cgroup *memcg, bool *locked,
|
|
unsigned long *flags)
|
|
{
|
|
if (memcg && *locked)
|
|
spin_unlock_irqrestore(&memcg->move_lock, *flags);
|
|
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_update_page_stat - update page state statistics
|
|
* @memcg: memcg to account against
|
|
* @idx: page state item to account
|
|
* @val: number of pages (positive or negative)
|
|
*
|
|
* See mem_cgroup_begin_page_stat() for locking requirements.
|
|
*/
|
|
void mem_cgroup_update_page_stat(struct mem_cgroup *memcg,
|
|
enum mem_cgroup_stat_index idx, int val)
|
|
{
|
|
VM_BUG_ON(!rcu_read_lock_held());
|
|
|
|
if (memcg)
|
|
this_cpu_add(memcg->stat->count[idx], val);
|
|
}
|
|
|
|
/*
|
|
* size of first charge trial. "32" comes from vmscan.c's magic value.
|
|
* TODO: maybe necessary to use big numbers in big irons.
|
|
*/
|
|
#define CHARGE_BATCH 32U
|
|
struct memcg_stock_pcp {
|
|
struct mem_cgroup *cached; /* this never be root cgroup */
|
|
unsigned int nr_pages;
|
|
struct work_struct work;
|
|
unsigned long flags;
|
|
#define FLUSHING_CACHED_CHARGE 0
|
|
};
|
|
static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
|
|
static DEFINE_MUTEX(percpu_charge_mutex);
|
|
|
|
/**
|
|
* consume_stock: Try to consume stocked charge on this cpu.
|
|
* @memcg: memcg to consume from.
|
|
* @nr_pages: how many pages to charge.
|
|
*
|
|
* The charges will only happen if @memcg matches the current cpu's memcg
|
|
* stock, and at least @nr_pages are available in that stock. Failure to
|
|
* service an allocation will refill the stock.
|
|
*
|
|
* returns true if successful, false otherwise.
|
|
*/
|
|
static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
|
|
{
|
|
struct memcg_stock_pcp *stock;
|
|
bool ret = false;
|
|
|
|
if (nr_pages > CHARGE_BATCH)
|
|
return ret;
|
|
|
|
stock = &get_cpu_var(memcg_stock);
|
|
if (memcg == stock->cached && stock->nr_pages >= nr_pages) {
|
|
stock->nr_pages -= nr_pages;
|
|
ret = true;
|
|
}
|
|
put_cpu_var(memcg_stock);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Returns stocks cached in percpu and reset cached information.
|
|
*/
|
|
static void drain_stock(struct memcg_stock_pcp *stock)
|
|
{
|
|
struct mem_cgroup *old = stock->cached;
|
|
|
|
if (stock->nr_pages) {
|
|
page_counter_uncharge(&old->memory, stock->nr_pages);
|
|
if (do_swap_account)
|
|
page_counter_uncharge(&old->memsw, stock->nr_pages);
|
|
css_put_many(&old->css, stock->nr_pages);
|
|
stock->nr_pages = 0;
|
|
}
|
|
stock->cached = NULL;
|
|
}
|
|
|
|
/*
|
|
* This must be called under preempt disabled or must be called by
|
|
* a thread which is pinned to local cpu.
|
|
*/
|
|
static void drain_local_stock(struct work_struct *dummy)
|
|
{
|
|
struct memcg_stock_pcp *stock = this_cpu_ptr(&memcg_stock);
|
|
drain_stock(stock);
|
|
clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
|
|
}
|
|
|
|
static void __init memcg_stock_init(void)
|
|
{
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
struct memcg_stock_pcp *stock =
|
|
&per_cpu(memcg_stock, cpu);
|
|
INIT_WORK(&stock->work, drain_local_stock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Cache charges(val) to local per_cpu area.
|
|
* This will be consumed by consume_stock() function, later.
|
|
*/
|
|
static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
|
|
{
|
|
struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
|
|
|
|
if (stock->cached != memcg) { /* reset if necessary */
|
|
drain_stock(stock);
|
|
stock->cached = memcg;
|
|
}
|
|
stock->nr_pages += nr_pages;
|
|
put_cpu_var(memcg_stock);
|
|
}
|
|
|
|
/*
|
|
* Drains all per-CPU charge caches for given root_memcg resp. subtree
|
|
* of the hierarchy under it.
|
|
*/
|
|
static void drain_all_stock(struct mem_cgroup *root_memcg)
|
|
{
|
|
int cpu, curcpu;
|
|
|
|
/* If someone's already draining, avoid adding running more workers. */
|
|
if (!mutex_trylock(&percpu_charge_mutex))
|
|
return;
|
|
/* Notify other cpus that system-wide "drain" is running */
|
|
get_online_cpus();
|
|
curcpu = get_cpu();
|
|
for_each_online_cpu(cpu) {
|
|
struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
|
|
struct mem_cgroup *memcg;
|
|
|
|
memcg = stock->cached;
|
|
if (!memcg || !stock->nr_pages)
|
|
continue;
|
|
if (!mem_cgroup_is_descendant(memcg, root_memcg))
|
|
continue;
|
|
if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) {
|
|
if (cpu == curcpu)
|
|
drain_local_stock(&stock->work);
|
|
else
|
|
schedule_work_on(cpu, &stock->work);
|
|
}
|
|
}
|
|
put_cpu();
|
|
put_online_cpus();
|
|
mutex_unlock(&percpu_charge_mutex);
|
|
}
|
|
|
|
/*
|
|
* This function drains percpu counter value from DEAD cpu and
|
|
* move it to local cpu. Note that this function can be preempted.
|
|
*/
|
|
static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu)
|
|
{
|
|
int i;
|
|
|
|
spin_lock(&memcg->pcp_counter_lock);
|
|
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
|
|
long x = per_cpu(memcg->stat->count[i], cpu);
|
|
|
|
per_cpu(memcg->stat->count[i], cpu) = 0;
|
|
memcg->nocpu_base.count[i] += x;
|
|
}
|
|
for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
|
|
unsigned long x = per_cpu(memcg->stat->events[i], cpu);
|
|
|
|
per_cpu(memcg->stat->events[i], cpu) = 0;
|
|
memcg->nocpu_base.events[i] += x;
|
|
}
|
|
spin_unlock(&memcg->pcp_counter_lock);
|
|
}
|
|
|
|
static int memcg_cpu_hotplug_callback(struct notifier_block *nb,
|
|
unsigned long action,
|
|
void *hcpu)
|
|
{
|
|
int cpu = (unsigned long)hcpu;
|
|
struct memcg_stock_pcp *stock;
|
|
struct mem_cgroup *iter;
|
|
|
|
if (action == CPU_ONLINE)
|
|
return NOTIFY_OK;
|
|
|
|
if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
|
|
return NOTIFY_OK;
|
|
|
|
for_each_mem_cgroup(iter)
|
|
mem_cgroup_drain_pcp_counter(iter, cpu);
|
|
|
|
stock = &per_cpu(memcg_stock, cpu);
|
|
drain_stock(stock);
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
|
|
unsigned int nr_pages)
|
|
{
|
|
unsigned int batch = max(CHARGE_BATCH, nr_pages);
|
|
int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
|
|
struct mem_cgroup *mem_over_limit;
|
|
struct page_counter *counter;
|
|
unsigned long nr_reclaimed;
|
|
bool may_swap = true;
|
|
bool drained = false;
|
|
int ret = 0;
|
|
|
|
if (mem_cgroup_is_root(memcg))
|
|
goto done;
|
|
retry:
|
|
if (consume_stock(memcg, nr_pages))
|
|
goto done;
|
|
|
|
if (!do_swap_account ||
|
|
!page_counter_try_charge(&memcg->memsw, batch, &counter)) {
|
|
if (!page_counter_try_charge(&memcg->memory, batch, &counter))
|
|
goto done_restock;
|
|
if (do_swap_account)
|
|
page_counter_uncharge(&memcg->memsw, batch);
|
|
mem_over_limit = mem_cgroup_from_counter(counter, memory);
|
|
} else {
|
|
mem_over_limit = mem_cgroup_from_counter(counter, memsw);
|
|
may_swap = false;
|
|
}
|
|
|
|
if (batch > nr_pages) {
|
|
batch = nr_pages;
|
|
goto retry;
|
|
}
|
|
|
|
/*
|
|
* Unlike in global OOM situations, memcg is not in a physical
|
|
* memory shortage. Allow dying and OOM-killed tasks to
|
|
* bypass the last charges so that they can exit quickly and
|
|
* free their memory.
|
|
*/
|
|
if (unlikely(test_thread_flag(TIF_MEMDIE) ||
|
|
fatal_signal_pending(current) ||
|
|
current->flags & PF_EXITING))
|
|
goto bypass;
|
|
|
|
if (unlikely(task_in_memcg_oom(current)))
|
|
goto nomem;
|
|
|
|
if (!(gfp_mask & __GFP_WAIT))
|
|
goto nomem;
|
|
|
|
nr_reclaimed = try_to_free_mem_cgroup_pages(mem_over_limit, nr_pages,
|
|
gfp_mask, may_swap);
|
|
|
|
if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
|
|
goto retry;
|
|
|
|
if (!drained) {
|
|
drain_all_stock(mem_over_limit);
|
|
drained = true;
|
|
goto retry;
|
|
}
|
|
|
|
if (gfp_mask & __GFP_NORETRY)
|
|
goto nomem;
|
|
/*
|
|
* Even though the limit is exceeded at this point, reclaim
|
|
* may have been able to free some pages. Retry the charge
|
|
* before killing the task.
|
|
*
|
|
* Only for regular pages, though: huge pages are rather
|
|
* unlikely to succeed so close to the limit, and we fall back
|
|
* to regular pages anyway in case of failure.
|
|
*/
|
|
if (nr_reclaimed && nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER))
|
|
goto retry;
|
|
/*
|
|
* At task move, charge accounts can be doubly counted. So, it's
|
|
* better to wait until the end of task_move if something is going on.
|
|
*/
|
|
if (mem_cgroup_wait_acct_move(mem_over_limit))
|
|
goto retry;
|
|
|
|
if (nr_retries--)
|
|
goto retry;
|
|
|
|
if (gfp_mask & __GFP_NOFAIL)
|
|
goto bypass;
|
|
|
|
if (fatal_signal_pending(current))
|
|
goto bypass;
|
|
|
|
mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(nr_pages));
|
|
nomem:
|
|
if (!(gfp_mask & __GFP_NOFAIL))
|
|
return -ENOMEM;
|
|
bypass:
|
|
return -EINTR;
|
|
|
|
done_restock:
|
|
css_get_many(&memcg->css, batch);
|
|
if (batch > nr_pages)
|
|
refill_stock(memcg, batch - nr_pages);
|
|
done:
|
|
return ret;
|
|
}
|
|
|
|
static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
|
|
{
|
|
if (mem_cgroup_is_root(memcg))
|
|
return;
|
|
|
|
page_counter_uncharge(&memcg->memory, nr_pages);
|
|
if (do_swap_account)
|
|
page_counter_uncharge(&memcg->memsw, nr_pages);
|
|
|
|
css_put_many(&memcg->css, nr_pages);
|
|
}
|
|
|
|
/*
|
|
* A helper function to get mem_cgroup from ID. must be called under
|
|
* rcu_read_lock(). The caller is responsible for calling
|
|
* css_tryget_online() if the mem_cgroup is used for charging. (dropping
|
|
* refcnt from swap can be called against removed memcg.)
|
|
*/
|
|
static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
|
|
{
|
|
/* ID 0 is unused ID */
|
|
if (!id)
|
|
return NULL;
|
|
return mem_cgroup_from_id(id);
|
|
}
|
|
|
|
/*
|
|
* try_get_mem_cgroup_from_page - look up page's memcg association
|
|
* @page: the page
|
|
*
|
|
* Look up, get a css reference, and return the memcg that owns @page.
|
|
*
|
|
* The page must be locked to prevent racing with swap-in and page
|
|
* cache charges. If coming from an unlocked page table, the caller
|
|
* must ensure the page is on the LRU or this can race with charging.
|
|
*/
|
|
struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
unsigned short id;
|
|
swp_entry_t ent;
|
|
|
|
VM_BUG_ON_PAGE(!PageLocked(page), page);
|
|
|
|
memcg = page->mem_cgroup;
|
|
if (memcg) {
|
|
if (!css_tryget_online(&memcg->css))
|
|
memcg = NULL;
|
|
} else if (PageSwapCache(page)) {
|
|
ent.val = page_private(page);
|
|
id = lookup_swap_cgroup_id(ent);
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_lookup(id);
|
|
if (memcg && !css_tryget_online(&memcg->css))
|
|
memcg = NULL;
|
|
rcu_read_unlock();
|
|
}
|
|
return memcg;
|
|
}
|
|
|
|
static void lock_page_lru(struct page *page, int *isolated)
|
|
{
|
|
struct zone *zone = page_zone(page);
|
|
|
|
spin_lock_irq(&zone->lru_lock);
|
|
if (PageLRU(page)) {
|
|
struct lruvec *lruvec;
|
|
|
|
lruvec = mem_cgroup_page_lruvec(page, zone);
|
|
ClearPageLRU(page);
|
|
del_page_from_lru_list(page, lruvec, page_lru(page));
|
|
*isolated = 1;
|
|
} else
|
|
*isolated = 0;
|
|
}
|
|
|
|
static void unlock_page_lru(struct page *page, int isolated)
|
|
{
|
|
struct zone *zone = page_zone(page);
|
|
|
|
if (isolated) {
|
|
struct lruvec *lruvec;
|
|
|
|
lruvec = mem_cgroup_page_lruvec(page, zone);
|
|
VM_BUG_ON_PAGE(PageLRU(page), page);
|
|
SetPageLRU(page);
|
|
add_page_to_lru_list(page, lruvec, page_lru(page));
|
|
}
|
|
spin_unlock_irq(&zone->lru_lock);
|
|
}
|
|
|
|
static void commit_charge(struct page *page, struct mem_cgroup *memcg,
|
|
bool lrucare)
|
|
{
|
|
int isolated;
|
|
|
|
VM_BUG_ON_PAGE(page->mem_cgroup, page);
|
|
|
|
/*
|
|
* In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
|
|
* may already be on some other mem_cgroup's LRU. Take care of it.
|
|
*/
|
|
if (lrucare)
|
|
lock_page_lru(page, &isolated);
|
|
|
|
/*
|
|
* Nobody should be changing or seriously looking at
|
|
* page->mem_cgroup at this point:
|
|
*
|
|
* - the page is uncharged
|
|
*
|
|
* - the page is off-LRU
|
|
*
|
|
* - an anonymous fault has exclusive page access, except for
|
|
* a locked page table
|
|
*
|
|
* - a page cache insertion, a swapin fault, or a migration
|
|
* have the page locked
|
|
*/
|
|
page->mem_cgroup = memcg;
|
|
|
|
if (lrucare)
|
|
unlock_page_lru(page, isolated);
|
|
}
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
/*
|
|
* The memcg_slab_mutex is held whenever a per memcg kmem cache is created or
|
|
* destroyed. It protects memcg_caches arrays and memcg_slab_caches lists.
|
|
*/
|
|
static DEFINE_MUTEX(memcg_slab_mutex);
|
|
|
|
/*
|
|
* This is a bit cumbersome, but it is rarely used and avoids a backpointer
|
|
* in the memcg_cache_params struct.
|
|
*/
|
|
static struct kmem_cache *memcg_params_to_cache(struct memcg_cache_params *p)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
|
|
VM_BUG_ON(p->is_root_cache);
|
|
cachep = p->root_cache;
|
|
return cache_from_memcg_idx(cachep, memcg_cache_id(p->memcg));
|
|
}
|
|
|
|
static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp,
|
|
unsigned long nr_pages)
|
|
{
|
|
struct page_counter *counter;
|
|
int ret = 0;
|
|
|
|
ret = page_counter_try_charge(&memcg->kmem, nr_pages, &counter);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = try_charge(memcg, gfp, nr_pages);
|
|
if (ret == -EINTR) {
|
|
/*
|
|
* try_charge() chose to bypass to root due to OOM kill or
|
|
* fatal signal. Since our only options are to either fail
|
|
* the allocation or charge it to this cgroup, do it as a
|
|
* temporary condition. But we can't fail. From a kmem/slab
|
|
* perspective, the cache has already been selected, by
|
|
* mem_cgroup_kmem_get_cache(), so it is too late to change
|
|
* our minds.
|
|
*
|
|
* This condition will only trigger if the task entered
|
|
* memcg_charge_kmem in a sane state, but was OOM-killed
|
|
* during try_charge() above. Tasks that were already dying
|
|
* when the allocation triggers should have been already
|
|
* directed to the root cgroup in memcontrol.h
|
|
*/
|
|
page_counter_charge(&memcg->memory, nr_pages);
|
|
if (do_swap_account)
|
|
page_counter_charge(&memcg->memsw, nr_pages);
|
|
css_get_many(&memcg->css, nr_pages);
|
|
ret = 0;
|
|
} else if (ret)
|
|
page_counter_uncharge(&memcg->kmem, nr_pages);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void memcg_uncharge_kmem(struct mem_cgroup *memcg,
|
|
unsigned long nr_pages)
|
|
{
|
|
page_counter_uncharge(&memcg->memory, nr_pages);
|
|
if (do_swap_account)
|
|
page_counter_uncharge(&memcg->memsw, nr_pages);
|
|
|
|
page_counter_uncharge(&memcg->kmem, nr_pages);
|
|
|
|
css_put_many(&memcg->css, nr_pages);
|
|
}
|
|
|
|
/*
|
|
* helper for acessing a memcg's index. It will be used as an index in the
|
|
* child cache array in kmem_cache, and also to derive its name. This function
|
|
* will return -1 when this is not a kmem-limited memcg.
|
|
*/
|
|
int memcg_cache_id(struct mem_cgroup *memcg)
|
|
{
|
|
return memcg ? memcg->kmemcg_id : -1;
|
|
}
|
|
|
|
static int memcg_alloc_cache_id(void)
|
|
{
|
|
int id, size;
|
|
int err;
|
|
|
|
id = ida_simple_get(&kmem_limited_groups,
|
|
0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL);
|
|
if (id < 0)
|
|
return id;
|
|
|
|
if (id < memcg_limited_groups_array_size)
|
|
return id;
|
|
|
|
/*
|
|
* There's no space for the new id in memcg_caches arrays,
|
|
* so we have to grow them.
|
|
*/
|
|
|
|
size = 2 * (id + 1);
|
|
if (size < MEMCG_CACHES_MIN_SIZE)
|
|
size = MEMCG_CACHES_MIN_SIZE;
|
|
else if (size > MEMCG_CACHES_MAX_SIZE)
|
|
size = MEMCG_CACHES_MAX_SIZE;
|
|
|
|
mutex_lock(&memcg_slab_mutex);
|
|
err = memcg_update_all_caches(size);
|
|
mutex_unlock(&memcg_slab_mutex);
|
|
|
|
if (err) {
|
|
ida_simple_remove(&kmem_limited_groups, id);
|
|
return err;
|
|
}
|
|
return id;
|
|
}
|
|
|
|
static void memcg_free_cache_id(int id)
|
|
{
|
|
ida_simple_remove(&kmem_limited_groups, id);
|
|
}
|
|
|
|
/*
|
|
* We should update the current array size iff all caches updates succeed. This
|
|
* can only be done from the slab side. The slab mutex needs to be held when
|
|
* calling this.
|
|
*/
|
|
void memcg_update_array_size(int num)
|
|
{
|
|
memcg_limited_groups_array_size = num;
|
|
}
|
|
|
|
static void memcg_register_cache(struct mem_cgroup *memcg,
|
|
struct kmem_cache *root_cache)
|
|
{
|
|
static char memcg_name_buf[NAME_MAX + 1]; /* protected by
|
|
memcg_slab_mutex */
|
|
struct kmem_cache *cachep;
|
|
int id;
|
|
|
|
lockdep_assert_held(&memcg_slab_mutex);
|
|
|
|
id = memcg_cache_id(memcg);
|
|
|
|
/*
|
|
* Since per-memcg caches are created asynchronously on first
|
|
* allocation (see memcg_kmem_get_cache()), several threads can try to
|
|
* create the same cache, but only one of them may succeed.
|
|
*/
|
|
if (cache_from_memcg_idx(root_cache, id))
|
|
return;
|
|
|
|
cgroup_name(memcg->css.cgroup, memcg_name_buf, NAME_MAX + 1);
|
|
cachep = memcg_create_kmem_cache(memcg, root_cache, memcg_name_buf);
|
|
/*
|
|
* If we could not create a memcg cache, do not complain, because
|
|
* that's not critical at all as we can always proceed with the root
|
|
* cache.
|
|
*/
|
|
if (!cachep)
|
|
return;
|
|
|
|
list_add(&cachep->memcg_params->list, &memcg->memcg_slab_caches);
|
|
|
|
/*
|
|
* Since readers won't lock (see cache_from_memcg_idx()), we need a
|
|
* barrier here to ensure nobody will see the kmem_cache partially
|
|
* initialized.
|
|
*/
|
|
smp_wmb();
|
|
|
|
BUG_ON(root_cache->memcg_params->memcg_caches[id]);
|
|
root_cache->memcg_params->memcg_caches[id] = cachep;
|
|
}
|
|
|
|
static void memcg_unregister_cache(struct kmem_cache *cachep)
|
|
{
|
|
struct kmem_cache *root_cache;
|
|
struct mem_cgroup *memcg;
|
|
int id;
|
|
|
|
lockdep_assert_held(&memcg_slab_mutex);
|
|
|
|
BUG_ON(is_root_cache(cachep));
|
|
|
|
root_cache = cachep->memcg_params->root_cache;
|
|
memcg = cachep->memcg_params->memcg;
|
|
id = memcg_cache_id(memcg);
|
|
|
|
BUG_ON(root_cache->memcg_params->memcg_caches[id] != cachep);
|
|
root_cache->memcg_params->memcg_caches[id] = NULL;
|
|
|
|
list_del(&cachep->memcg_params->list);
|
|
|
|
kmem_cache_destroy(cachep);
|
|
}
|
|
|
|
int __memcg_cleanup_cache_params(struct kmem_cache *s)
|
|
{
|
|
struct kmem_cache *c;
|
|
int i, failed = 0;
|
|
|
|
mutex_lock(&memcg_slab_mutex);
|
|
for_each_memcg_cache_index(i) {
|
|
c = cache_from_memcg_idx(s, i);
|
|
if (!c)
|
|
continue;
|
|
|
|
memcg_unregister_cache(c);
|
|
|
|
if (cache_from_memcg_idx(s, i))
|
|
failed++;
|
|
}
|
|
mutex_unlock(&memcg_slab_mutex);
|
|
return failed;
|
|
}
|
|
|
|
static void memcg_unregister_all_caches(struct mem_cgroup *memcg)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
struct memcg_cache_params *params, *tmp;
|
|
|
|
if (!memcg_kmem_is_active(memcg))
|
|
return;
|
|
|
|
mutex_lock(&memcg_slab_mutex);
|
|
list_for_each_entry_safe(params, tmp, &memcg->memcg_slab_caches, list) {
|
|
cachep = memcg_params_to_cache(params);
|
|
memcg_unregister_cache(cachep);
|
|
}
|
|
mutex_unlock(&memcg_slab_mutex);
|
|
}
|
|
|
|
struct memcg_register_cache_work {
|
|
struct mem_cgroup *memcg;
|
|
struct kmem_cache *cachep;
|
|
struct work_struct work;
|
|
};
|
|
|
|
static void memcg_register_cache_func(struct work_struct *w)
|
|
{
|
|
struct memcg_register_cache_work *cw =
|
|
container_of(w, struct memcg_register_cache_work, work);
|
|
struct mem_cgroup *memcg = cw->memcg;
|
|
struct kmem_cache *cachep = cw->cachep;
|
|
|
|
mutex_lock(&memcg_slab_mutex);
|
|
memcg_register_cache(memcg, cachep);
|
|
mutex_unlock(&memcg_slab_mutex);
|
|
|
|
css_put(&memcg->css);
|
|
kfree(cw);
|
|
}
|
|
|
|
/*
|
|
* Enqueue the creation of a per-memcg kmem_cache.
|
|
*/
|
|
static void __memcg_schedule_register_cache(struct mem_cgroup *memcg,
|
|
struct kmem_cache *cachep)
|
|
{
|
|
struct memcg_register_cache_work *cw;
|
|
|
|
cw = kmalloc(sizeof(*cw), GFP_NOWAIT);
|
|
if (!cw)
|
|
return;
|
|
|
|
css_get(&memcg->css);
|
|
|
|
cw->memcg = memcg;
|
|
cw->cachep = cachep;
|
|
|
|
INIT_WORK(&cw->work, memcg_register_cache_func);
|
|
schedule_work(&cw->work);
|
|
}
|
|
|
|
static void memcg_schedule_register_cache(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_register_cache 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_register_cache(memcg, cachep);
|
|
current->memcg_kmem_skip_account = 0;
|
|
}
|
|
|
|
int __memcg_charge_slab(struct kmem_cache *cachep, gfp_t gfp, int order)
|
|
{
|
|
unsigned int nr_pages = 1 << order;
|
|
|
|
return memcg_charge_kmem(cachep->memcg_params->memcg, gfp, nr_pages);
|
|
}
|
|
|
|
void __memcg_uncharge_slab(struct kmem_cache *cachep, int order)
|
|
{
|
|
unsigned int nr_pages = 1 << order;
|
|
|
|
memcg_uncharge_kmem(cachep->memcg_params->memcg, nr_pages);
|
|
}
|
|
|
|
/*
|
|
* Return the kmem_cache we're supposed to use for a slab allocation.
|
|
* We try to use the current memcg's version of the cache.
|
|
*
|
|
* If the cache does not exist yet, if we are the first user of it,
|
|
* we either create it immediately, if possible, or create it asynchronously
|
|
* in a workqueue.
|
|
* In the latter case, we will let the current allocation go through with
|
|
* the original cache.
|
|
*
|
|
* Can't be called in interrupt context or from kernel threads.
|
|
* This function needs to be called with rcu_read_lock() held.
|
|
*/
|
|
struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
struct kmem_cache *memcg_cachep;
|
|
|
|
VM_BUG_ON(!cachep->memcg_params);
|
|
VM_BUG_ON(!cachep->memcg_params->is_root_cache);
|
|
|
|
if (current->memcg_kmem_skip_account)
|
|
return cachep;
|
|
|
|
memcg = get_mem_cgroup_from_mm(current->mm);
|
|
if (!memcg_kmem_is_active(memcg))
|
|
goto out;
|
|
|
|
memcg_cachep = cache_from_memcg_idx(cachep, memcg_cache_id(memcg));
|
|
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_register_cache(memcg, cachep);
|
|
out:
|
|
css_put(&memcg->css);
|
|
return cachep;
|
|
}
|
|
|
|
void __memcg_kmem_put_cache(struct kmem_cache *cachep)
|
|
{
|
|
if (!is_root_cache(cachep))
|
|
css_put(&cachep->memcg_params->memcg->css);
|
|
}
|
|
|
|
/*
|
|
* We need to verify if the allocation against current->mm->owner's memcg is
|
|
* possible for the given order. But the page is not allocated yet, so we'll
|
|
* need a further commit step to do the final arrangements.
|
|
*
|
|
* It is possible for the task to switch cgroups in this mean time, so at
|
|
* commit time, we can't rely on task conversion any longer. We'll then use
|
|
* the handle argument to return to the caller which cgroup we should commit
|
|
* against. We could also return the memcg directly and avoid the pointer
|
|
* passing, but a boolean return value gives better semantics considering
|
|
* the compiled-out case as well.
|
|
*
|
|
* Returning true means the allocation is possible.
|
|
*/
|
|
bool
|
|
__memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
int ret;
|
|
|
|
*_memcg = NULL;
|
|
|
|
memcg = get_mem_cgroup_from_mm(current->mm);
|
|
|
|
if (!memcg_kmem_is_active(memcg)) {
|
|
css_put(&memcg->css);
|
|
return true;
|
|
}
|
|
|
|
ret = memcg_charge_kmem(memcg, gfp, 1 << order);
|
|
if (!ret)
|
|
*_memcg = memcg;
|
|
|
|
css_put(&memcg->css);
|
|
return (ret == 0);
|
|
}
|
|
|
|
void __memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg,
|
|
int order)
|
|
{
|
|
VM_BUG_ON(mem_cgroup_is_root(memcg));
|
|
|
|
/* The page allocation failed. Revert */
|
|
if (!page) {
|
|
memcg_uncharge_kmem(memcg, 1 << order);
|
|
return;
|
|
}
|
|
page->mem_cgroup = memcg;
|
|
}
|
|
|
|
void __memcg_kmem_uncharge_pages(struct page *page, int order)
|
|
{
|
|
struct mem_cgroup *memcg = page->mem_cgroup;
|
|
|
|
if (!memcg)
|
|
return;
|
|
|
|
VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg), page);
|
|
|
|
memcg_uncharge_kmem(memcg, 1 << order);
|
|
page->mem_cgroup = NULL;
|
|
}
|
|
#endif /* CONFIG_MEMCG_KMEM */
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
|
|
/*
|
|
* Because tail pages are not marked as "used", set it. We're under
|
|
* zone->lru_lock, 'splitting on pmd' and compound_lock.
|
|
* charge/uncharge will be never happen and move_account() is done under
|
|
* compound_lock(), so we don't have to take care of races.
|
|
*/
|
|
void mem_cgroup_split_huge_fixup(struct page *head)
|
|
{
|
|
int i;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
for (i = 1; i < HPAGE_PMD_NR; i++)
|
|
head[i].mem_cgroup = head->mem_cgroup;
|
|
|
|
__this_cpu_sub(head->mem_cgroup->stat->count[MEM_CGROUP_STAT_RSS_HUGE],
|
|
HPAGE_PMD_NR);
|
|
}
|
|
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
|
|
|
|
/**
|
|
* mem_cgroup_move_account - move account of the page
|
|
* @page: the page
|
|
* @nr_pages: number of regular pages (>1 for huge pages)
|
|
* @from: mem_cgroup which the page is moved from.
|
|
* @to: mem_cgroup which the page is moved to. @from != @to.
|
|
*
|
|
* The caller must confirm following.
|
|
* - page is not on LRU (isolate_page() is useful.)
|
|
* - compound_lock is held when nr_pages > 1
|
|
*
|
|
* This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
|
|
* from old cgroup.
|
|
*/
|
|
static int mem_cgroup_move_account(struct page *page,
|
|
unsigned int nr_pages,
|
|
struct mem_cgroup *from,
|
|
struct mem_cgroup *to)
|
|
{
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
VM_BUG_ON(from == to);
|
|
VM_BUG_ON_PAGE(PageLRU(page), page);
|
|
/*
|
|
* The page is isolated from LRU. So, collapse function
|
|
* will not handle this page. But page splitting can happen.
|
|
* Do this check under compound_page_lock(). The caller should
|
|
* hold it.
|
|
*/
|
|
ret = -EBUSY;
|
|
if (nr_pages > 1 && !PageTransHuge(page))
|
|
goto out;
|
|
|
|
/*
|
|
* Prevent mem_cgroup_migrate() from looking at page->mem_cgroup
|
|
* of its source page while we change it: page migration takes
|
|
* both pages off the LRU, but page cache replacement doesn't.
|
|
*/
|
|
if (!trylock_page(page))
|
|
goto out;
|
|
|
|
ret = -EINVAL;
|
|
if (page->mem_cgroup != from)
|
|
goto out_unlock;
|
|
|
|
spin_lock_irqsave(&from->move_lock, flags);
|
|
|
|
if (!PageAnon(page) && page_mapped(page)) {
|
|
__this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED],
|
|
nr_pages);
|
|
__this_cpu_add(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED],
|
|
nr_pages);
|
|
}
|
|
|
|
if (PageWriteback(page)) {
|
|
__this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_WRITEBACK],
|
|
nr_pages);
|
|
__this_cpu_add(to->stat->count[MEM_CGROUP_STAT_WRITEBACK],
|
|
nr_pages);
|
|
}
|
|
|
|
/*
|
|
* It is safe to change page->mem_cgroup here because the page
|
|
* is referenced, charged, and isolated - we can't race with
|
|
* uncharging, charging, migration, or LRU putback.
|
|
*/
|
|
|
|
/* caller should have done css_get */
|
|
page->mem_cgroup = to;
|
|
spin_unlock_irqrestore(&from->move_lock, flags);
|
|
|
|
ret = 0;
|
|
|
|
local_irq_disable();
|
|
mem_cgroup_charge_statistics(to, page, nr_pages);
|
|
memcg_check_events(to, page);
|
|
mem_cgroup_charge_statistics(from, page, -nr_pages);
|
|
memcg_check_events(from, page);
|
|
local_irq_enable();
|
|
out_unlock:
|
|
unlock_page(page);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_MEMCG_SWAP
|
|
static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,
|
|
bool charge)
|
|
{
|
|
int val = (charge) ? 1 : -1;
|
|
this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val);
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
|
|
* @entry: swap entry to be moved
|
|
* @from: mem_cgroup which the entry is moved from
|
|
* @to: mem_cgroup which the entry is moved to
|
|
*
|
|
* It succeeds only when the swap_cgroup's record for this entry is the same
|
|
* as the mem_cgroup's id of @from.
|
|
*
|
|
* Returns 0 on success, -EINVAL on failure.
|
|
*
|
|
* The caller must have charged to @to, IOW, called page_counter_charge() about
|
|
* both res and memsw, and called css_get().
|
|
*/
|
|
static int mem_cgroup_move_swap_account(swp_entry_t entry,
|
|
struct mem_cgroup *from, struct mem_cgroup *to)
|
|
{
|
|
unsigned short old_id, new_id;
|
|
|
|
old_id = mem_cgroup_id(from);
|
|
new_id = mem_cgroup_id(to);
|
|
|
|
if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
|
|
mem_cgroup_swap_statistics(from, false);
|
|
mem_cgroup_swap_statistics(to, true);
|
|
/*
|
|
* This function is only called from task migration context now.
|
|
* It postpones page_counter and refcount handling till the end
|
|
* of task migration(mem_cgroup_clear_mc()) for performance
|
|
* improvement. But we cannot postpone css_get(to) because if
|
|
* the process that has been moved to @to does swap-in, the
|
|
* refcount of @to might be decreased to 0.
|
|
*
|
|
* We are in attach() phase, so the cgroup is guaranteed to be
|
|
* alive, so we can just call css_get().
|
|
*/
|
|
css_get(&to->css);
|
|
return 0;
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
#else
|
|
static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
|
|
struct mem_cgroup *from, struct mem_cgroup *to)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
#endif
|
|
|
|
static DEFINE_MUTEX(memcg_limit_mutex);
|
|
|
|
static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
|
|
unsigned long limit)
|
|
{
|
|
unsigned long curusage;
|
|
unsigned long oldusage;
|
|
bool enlarge = false;
|
|
int retry_count;
|
|
int ret;
|
|
|
|
/*
|
|
* For keeping hierarchical_reclaim simple, how long we should retry
|
|
* is depends on callers. We set our retry-count to be function
|
|
* of # of children which we should visit in this loop.
|
|
*/
|
|
retry_count = MEM_CGROUP_RECLAIM_RETRIES *
|
|
mem_cgroup_count_children(memcg);
|
|
|
|
oldusage = page_counter_read(&memcg->memory);
|
|
|
|
do {
|
|
if (signal_pending(current)) {
|
|
ret = -EINTR;
|
|
break;
|
|
}
|
|
|
|
mutex_lock(&memcg_limit_mutex);
|
|
if (limit > memcg->memsw.limit) {
|
|
mutex_unlock(&memcg_limit_mutex);
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
if (limit > memcg->memory.limit)
|
|
enlarge = true;
|
|
ret = page_counter_limit(&memcg->memory, limit);
|
|
mutex_unlock(&memcg_limit_mutex);
|
|
|
|
if (!ret)
|
|
break;
|
|
|
|
try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, true);
|
|
|
|
curusage = page_counter_read(&memcg->memory);
|
|
/* Usage is reduced ? */
|
|
if (curusage >= oldusage)
|
|
retry_count--;
|
|
else
|
|
oldusage = curusage;
|
|
} while (retry_count);
|
|
|
|
if (!ret && enlarge)
|
|
memcg_oom_recover(memcg);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
|
|
unsigned long limit)
|
|
{
|
|
unsigned long curusage;
|
|
unsigned long oldusage;
|
|
bool enlarge = false;
|
|
int retry_count;
|
|
int ret;
|
|
|
|
/* see mem_cgroup_resize_res_limit */
|
|
retry_count = MEM_CGROUP_RECLAIM_RETRIES *
|
|
mem_cgroup_count_children(memcg);
|
|
|
|
oldusage = page_counter_read(&memcg->memsw);
|
|
|
|
do {
|
|
if (signal_pending(current)) {
|
|
ret = -EINTR;
|
|
break;
|
|
}
|
|
|
|
mutex_lock(&memcg_limit_mutex);
|
|
if (limit < memcg->memory.limit) {
|
|
mutex_unlock(&memcg_limit_mutex);
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
if (limit > memcg->memsw.limit)
|
|
enlarge = true;
|
|
ret = page_counter_limit(&memcg->memsw, limit);
|
|
mutex_unlock(&memcg_limit_mutex);
|
|
|
|
if (!ret)
|
|
break;
|
|
|
|
try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, false);
|
|
|
|
curusage = page_counter_read(&memcg->memsw);
|
|
/* Usage is reduced ? */
|
|
if (curusage >= oldusage)
|
|
retry_count--;
|
|
else
|
|
oldusage = curusage;
|
|
} while (retry_count);
|
|
|
|
if (!ret && enlarge)
|
|
memcg_oom_recover(memcg);
|
|
|
|
return ret;
|
|
}
|
|
|
|
unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
|
|
gfp_t gfp_mask,
|
|
unsigned long *total_scanned)
|
|
{
|
|
unsigned long nr_reclaimed = 0;
|
|
struct mem_cgroup_per_zone *mz, *next_mz = NULL;
|
|
unsigned long reclaimed;
|
|
int loop = 0;
|
|
struct mem_cgroup_tree_per_zone *mctz;
|
|
unsigned long excess;
|
|
unsigned long nr_scanned;
|
|
|
|
if (order > 0)
|
|
return 0;
|
|
|
|
mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone));
|
|
/*
|
|
* This loop can run a while, specially if mem_cgroup's continuously
|
|
* keep exceeding their soft limit and putting the system under
|
|
* pressure
|
|
*/
|
|
do {
|
|
if (next_mz)
|
|
mz = next_mz;
|
|
else
|
|
mz = mem_cgroup_largest_soft_limit_node(mctz);
|
|
if (!mz)
|
|
break;
|
|
|
|
nr_scanned = 0;
|
|
reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone,
|
|
gfp_mask, &nr_scanned);
|
|
nr_reclaimed += reclaimed;
|
|
*total_scanned += nr_scanned;
|
|
spin_lock_irq(&mctz->lock);
|
|
__mem_cgroup_remove_exceeded(mz, mctz);
|
|
|
|
/*
|
|
* If we failed to reclaim anything from this memory cgroup
|
|
* it is time to move on to the next cgroup
|
|
*/
|
|
next_mz = NULL;
|
|
if (!reclaimed)
|
|
next_mz = __mem_cgroup_largest_soft_limit_node(mctz);
|
|
|
|
excess = soft_limit_excess(mz->memcg);
|
|
/*
|
|
* One school of thought says that we should not add
|
|
* back the node to the tree if reclaim returns 0.
|
|
* But our reclaim could return 0, simply because due
|
|
* to priority we are exposing a smaller subset of
|
|
* memory to reclaim from. Consider this as a longer
|
|
* term TODO.
|
|
*/
|
|
/* If excess == 0, no tree ops */
|
|
__mem_cgroup_insert_exceeded(mz, mctz, excess);
|
|
spin_unlock_irq(&mctz->lock);
|
|
css_put(&mz->memcg->css);
|
|
loop++;
|
|
/*
|
|
* Could not reclaim anything and there are no more
|
|
* mem cgroups to try or we seem to be looping without
|
|
* reclaiming anything.
|
|
*/
|
|
if (!nr_reclaimed &&
|
|
(next_mz == NULL ||
|
|
loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
|
|
break;
|
|
} while (!nr_reclaimed);
|
|
if (next_mz)
|
|
css_put(&next_mz->memcg->css);
|
|
return nr_reclaimed;
|
|
}
|
|
|
|
/*
|
|
* Test whether @memcg has children, dead or alive. Note that this
|
|
* function doesn't care whether @memcg has use_hierarchy enabled and
|
|
* returns %true if there are child csses according to the cgroup
|
|
* hierarchy. Testing use_hierarchy is the caller's responsiblity.
|
|
*/
|
|
static inline bool memcg_has_children(struct mem_cgroup *memcg)
|
|
{
|
|
bool ret;
|
|
|
|
/*
|
|
* The lock does not prevent addition or deletion of children, but
|
|
* it prevents a new child from being initialized based on this
|
|
* parent in css_online(), so it's enough to decide whether
|
|
* hierarchically inherited attributes can still be changed or not.
|
|
*/
|
|
lockdep_assert_held(&memcg_create_mutex);
|
|
|
|
rcu_read_lock();
|
|
ret = css_next_child(NULL, &memcg->css);
|
|
rcu_read_unlock();
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Reclaims as many pages from the given memcg as possible and moves
|
|
* the rest to the parent.
|
|
*
|
|
* Caller is responsible for holding css reference for memcg.
|
|
*/
|
|
static int mem_cgroup_force_empty(struct mem_cgroup *memcg)
|
|
{
|
|
int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
|
|
|
|
/* we call try-to-free pages for make this cgroup empty */
|
|
lru_add_drain_all();
|
|
/* try to free all pages in this cgroup */
|
|
while (nr_retries && page_counter_read(&memcg->memory)) {
|
|
int progress;
|
|
|
|
if (signal_pending(current))
|
|
return -EINTR;
|
|
|
|
progress = try_to_free_mem_cgroup_pages(memcg, 1,
|
|
GFP_KERNEL, true);
|
|
if (!progress) {
|
|
nr_retries--;
|
|
/* maybe some writeback is necessary */
|
|
congestion_wait(BLK_RW_ASYNC, HZ/10);
|
|
}
|
|
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t mem_cgroup_force_empty_write(struct kernfs_open_file *of,
|
|
char *buf, size_t nbytes,
|
|
loff_t off)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
|
|
|
|
if (mem_cgroup_is_root(memcg))
|
|
return -EINVAL;
|
|
return mem_cgroup_force_empty(memcg) ?: nbytes;
|
|
}
|
|
|
|
static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
return mem_cgroup_from_css(css)->use_hierarchy;
|
|
}
|
|
|
|
static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
int retval = 0;
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup *parent_memcg = mem_cgroup_from_css(memcg->css.parent);
|
|
|
|
mutex_lock(&memcg_create_mutex);
|
|
|
|
if (memcg->use_hierarchy == val)
|
|
goto out;
|
|
|
|
/*
|
|
* If parent's use_hierarchy is set, we can't make any modifications
|
|
* in the child subtrees. If it is unset, then the change can
|
|
* occur, provided the current cgroup has no children.
|
|
*
|
|
* For the root cgroup, parent_mem is NULL, we allow value to be
|
|
* set if there are no children.
|
|
*/
|
|
if ((!parent_memcg || !parent_memcg->use_hierarchy) &&
|
|
(val == 1 || val == 0)) {
|
|
if (!memcg_has_children(memcg))
|
|
memcg->use_hierarchy = val;
|
|
else
|
|
retval = -EBUSY;
|
|
} else
|
|
retval = -EINVAL;
|
|
|
|
out:
|
|
mutex_unlock(&memcg_create_mutex);
|
|
|
|
return retval;
|
|
}
|
|
|
|
static unsigned long tree_stat(struct mem_cgroup *memcg,
|
|
enum mem_cgroup_stat_index idx)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
long val = 0;
|
|
|
|
/* Per-cpu values can be negative, use a signed accumulator */
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
val += mem_cgroup_read_stat(iter, idx);
|
|
|
|
if (val < 0) /* race ? */
|
|
val = 0;
|
|
return val;
|
|
}
|
|
|
|
static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
|
|
{
|
|
u64 val;
|
|
|
|
if (mem_cgroup_is_root(memcg)) {
|
|
val = tree_stat(memcg, MEM_CGROUP_STAT_CACHE);
|
|
val += tree_stat(memcg, MEM_CGROUP_STAT_RSS);
|
|
if (swap)
|
|
val += tree_stat(memcg, MEM_CGROUP_STAT_SWAP);
|
|
} else {
|
|
if (!swap)
|
|
val = page_counter_read(&memcg->memory);
|
|
else
|
|
val = page_counter_read(&memcg->memsw);
|
|
}
|
|
return val << PAGE_SHIFT;
|
|
}
|
|
|
|
enum {
|
|
RES_USAGE,
|
|
RES_LIMIT,
|
|
RES_MAX_USAGE,
|
|
RES_FAILCNT,
|
|
RES_SOFT_LIMIT,
|
|
};
|
|
|
|
static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct page_counter *counter;
|
|
|
|
switch (MEMFILE_TYPE(cft->private)) {
|
|
case _MEM:
|
|
counter = &memcg->memory;
|
|
break;
|
|
case _MEMSWAP:
|
|
counter = &memcg->memsw;
|
|
break;
|
|
case _KMEM:
|
|
counter = &memcg->kmem;
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
switch (MEMFILE_ATTR(cft->private)) {
|
|
case RES_USAGE:
|
|
if (counter == &memcg->memory)
|
|
return mem_cgroup_usage(memcg, false);
|
|
if (counter == &memcg->memsw)
|
|
return mem_cgroup_usage(memcg, true);
|
|
return (u64)page_counter_read(counter) * PAGE_SIZE;
|
|
case RES_LIMIT:
|
|
return (u64)counter->limit * PAGE_SIZE;
|
|
case RES_MAX_USAGE:
|
|
return (u64)counter->watermark * PAGE_SIZE;
|
|
case RES_FAILCNT:
|
|
return counter->failcnt;
|
|
case RES_SOFT_LIMIT:
|
|
return (u64)memcg->soft_limit * PAGE_SIZE;
|
|
default:
|
|
BUG();
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
static int memcg_activate_kmem(struct mem_cgroup *memcg,
|
|
unsigned long nr_pages)
|
|
{
|
|
int err = 0;
|
|
int memcg_id;
|
|
|
|
if (memcg_kmem_is_active(memcg))
|
|
return 0;
|
|
|
|
/*
|
|
* For simplicity, we won't allow this to be disabled. It also can't
|
|
* be changed if the cgroup has children already, or if tasks had
|
|
* already joined.
|
|
*
|
|
* If tasks join before we set the limit, a person looking at
|
|
* kmem.usage_in_bytes will have no way to determine when it took
|
|
* place, which makes the value quite meaningless.
|
|
*
|
|
* After it first became limited, changes in the value of the limit are
|
|
* of course permitted.
|
|
*/
|
|
mutex_lock(&memcg_create_mutex);
|
|
if (cgroup_has_tasks(memcg->css.cgroup) ||
|
|
(memcg->use_hierarchy && memcg_has_children(memcg)))
|
|
err = -EBUSY;
|
|
mutex_unlock(&memcg_create_mutex);
|
|
if (err)
|
|
goto out;
|
|
|
|
memcg_id = memcg_alloc_cache_id();
|
|
if (memcg_id < 0) {
|
|
err = memcg_id;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* We couldn't have accounted to this cgroup, because it hasn't got
|
|
* activated yet, so this should succeed.
|
|
*/
|
|
err = page_counter_limit(&memcg->kmem, nr_pages);
|
|
VM_BUG_ON(err);
|
|
|
|
static_key_slow_inc(&memcg_kmem_enabled_key);
|
|
/*
|
|
* A memory cgroup is considered kmem-active as soon as it gets
|
|
* kmemcg_id. Setting the id after enabling static branching will
|
|
* guarantee no one starts accounting before all call sites are
|
|
* patched.
|
|
*/
|
|
memcg->kmemcg_id = memcg_id;
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
|
|
unsigned long limit)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&memcg_limit_mutex);
|
|
if (!memcg_kmem_is_active(memcg))
|
|
ret = memcg_activate_kmem(memcg, limit);
|
|
else
|
|
ret = page_counter_limit(&memcg->kmem, limit);
|
|
mutex_unlock(&memcg_limit_mutex);
|
|
return ret;
|
|
}
|
|
|
|
static int memcg_propagate_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
int ret = 0;
|
|
struct mem_cgroup *parent = parent_mem_cgroup(memcg);
|
|
|
|
if (!parent)
|
|
return 0;
|
|
|
|
mutex_lock(&memcg_limit_mutex);
|
|
/*
|
|
* If the parent cgroup is not kmem-active now, it cannot be activated
|
|
* after this point, because it has at least one child already.
|
|
*/
|
|
if (memcg_kmem_is_active(parent))
|
|
ret = memcg_activate_kmem(memcg, PAGE_COUNTER_MAX);
|
|
mutex_unlock(&memcg_limit_mutex);
|
|
return ret;
|
|
}
|
|
#else
|
|
static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
|
|
unsigned long limit)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
#endif /* CONFIG_MEMCG_KMEM */
|
|
|
|
/*
|
|
* The user of this function is...
|
|
* RES_LIMIT.
|
|
*/
|
|
static ssize_t mem_cgroup_write(struct kernfs_open_file *of,
|
|
char *buf, size_t nbytes, loff_t off)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
|
|
unsigned long nr_pages;
|
|
int ret;
|
|
|
|
buf = strstrip(buf);
|
|
ret = page_counter_memparse(buf, &nr_pages);
|
|
if (ret)
|
|
return ret;
|
|
|
|
switch (MEMFILE_ATTR(of_cft(of)->private)) {
|
|
case RES_LIMIT:
|
|
if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
switch (MEMFILE_TYPE(of_cft(of)->private)) {
|
|
case _MEM:
|
|
ret = mem_cgroup_resize_limit(memcg, nr_pages);
|
|
break;
|
|
case _MEMSWAP:
|
|
ret = mem_cgroup_resize_memsw_limit(memcg, nr_pages);
|
|
break;
|
|
case _KMEM:
|
|
ret = memcg_update_kmem_limit(memcg, nr_pages);
|
|
break;
|
|
}
|
|
break;
|
|
case RES_SOFT_LIMIT:
|
|
memcg->soft_limit = nr_pages;
|
|
ret = 0;
|
|
break;
|
|
}
|
|
return ret ?: nbytes;
|
|
}
|
|
|
|
static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf,
|
|
size_t nbytes, loff_t off)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
|
|
struct page_counter *counter;
|
|
|
|
switch (MEMFILE_TYPE(of_cft(of)->private)) {
|
|
case _MEM:
|
|
counter = &memcg->memory;
|
|
break;
|
|
case _MEMSWAP:
|
|
counter = &memcg->memsw;
|
|
break;
|
|
case _KMEM:
|
|
counter = &memcg->kmem;
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
switch (MEMFILE_ATTR(of_cft(of)->private)) {
|
|
case RES_MAX_USAGE:
|
|
page_counter_reset_watermark(counter);
|
|
break;
|
|
case RES_FAILCNT:
|
|
counter->failcnt = 0;
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
return nbytes;
|
|
}
|
|
|
|
static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
return mem_cgroup_from_css(css)->move_charge_at_immigrate;
|
|
}
|
|
|
|
#ifdef CONFIG_MMU
|
|
static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
if (val >= (1 << NR_MOVE_TYPE))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* No kind of locking is needed in here, because ->can_attach() will
|
|
* check this value once in the beginning of the process, and then carry
|
|
* on with stale data. This means that changes to this value will only
|
|
* affect task migrations starting after the change.
|
|
*/
|
|
memcg->move_charge_at_immigrate = val;
|
|
return 0;
|
|
}
|
|
#else
|
|
static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_NUMA
|
|
static int memcg_numa_stat_show(struct seq_file *m, void *v)
|
|
{
|
|
struct numa_stat {
|
|
const char *name;
|
|
unsigned int lru_mask;
|
|
};
|
|
|
|
static const struct numa_stat stats[] = {
|
|
{ "total", LRU_ALL },
|
|
{ "file", LRU_ALL_FILE },
|
|
{ "anon", LRU_ALL_ANON },
|
|
{ "unevictable", BIT(LRU_UNEVICTABLE) },
|
|
};
|
|
const struct numa_stat *stat;
|
|
int nid;
|
|
unsigned long nr;
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
|
|
|
|
for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
|
|
nr = mem_cgroup_nr_lru_pages(memcg, stat->lru_mask);
|
|
seq_printf(m, "%s=%lu", stat->name, nr);
|
|
for_each_node_state(nid, N_MEMORY) {
|
|
nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
|
|
stat->lru_mask);
|
|
seq_printf(m, " N%d=%lu", nid, nr);
|
|
}
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
|
|
struct mem_cgroup *iter;
|
|
|
|
nr = 0;
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
nr += mem_cgroup_nr_lru_pages(iter, stat->lru_mask);
|
|
seq_printf(m, "hierarchical_%s=%lu", stat->name, nr);
|
|
for_each_node_state(nid, N_MEMORY) {
|
|
nr = 0;
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
nr += mem_cgroup_node_nr_lru_pages(
|
|
iter, nid, stat->lru_mask);
|
|
seq_printf(m, " N%d=%lu", nid, nr);
|
|
}
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_NUMA */
|
|
|
|
static int memcg_stat_show(struct seq_file *m, void *v)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
|
|
unsigned long memory, memsw;
|
|
struct mem_cgroup *mi;
|
|
unsigned int i;
|
|
|
|
BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS);
|
|
|
|
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
|
|
if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
|
|
continue;
|
|
seq_printf(m, "%s %ld\n", mem_cgroup_stat_names[i],
|
|
mem_cgroup_read_stat(memcg, i) * PAGE_SIZE);
|
|
}
|
|
|
|
for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++)
|
|
seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i],
|
|
mem_cgroup_read_events(memcg, i));
|
|
|
|
for (i = 0; i < NR_LRU_LISTS; i++)
|
|
seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i],
|
|
mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE);
|
|
|
|
/* Hierarchical information */
|
|
memory = memsw = PAGE_COUNTER_MAX;
|
|
for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) {
|
|
memory = min(memory, mi->memory.limit);
|
|
memsw = min(memsw, mi->memsw.limit);
|
|
}
|
|
seq_printf(m, "hierarchical_memory_limit %llu\n",
|
|
(u64)memory * PAGE_SIZE);
|
|
if (do_swap_account)
|
|
seq_printf(m, "hierarchical_memsw_limit %llu\n",
|
|
(u64)memsw * PAGE_SIZE);
|
|
|
|
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
|
|
long long val = 0;
|
|
|
|
if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
|
|
continue;
|
|
for_each_mem_cgroup_tree(mi, memcg)
|
|
val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE;
|
|
seq_printf(m, "total_%s %lld\n", mem_cgroup_stat_names[i], val);
|
|
}
|
|
|
|
for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
|
|
unsigned long long val = 0;
|
|
|
|
for_each_mem_cgroup_tree(mi, memcg)
|
|
val += mem_cgroup_read_events(mi, i);
|
|
seq_printf(m, "total_%s %llu\n",
|
|
mem_cgroup_events_names[i], val);
|
|
}
|
|
|
|
for (i = 0; i < NR_LRU_LISTS; i++) {
|
|
unsigned long long val = 0;
|
|
|
|
for_each_mem_cgroup_tree(mi, memcg)
|
|
val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE;
|
|
seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val);
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_VM
|
|
{
|
|
int nid, zid;
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct zone_reclaim_stat *rstat;
|
|
unsigned long recent_rotated[2] = {0, 0};
|
|
unsigned long recent_scanned[2] = {0, 0};
|
|
|
|
for_each_online_node(nid)
|
|
for (zid = 0; zid < MAX_NR_ZONES; zid++) {
|
|
mz = &memcg->nodeinfo[nid]->zoneinfo[zid];
|
|
rstat = &mz->lruvec.reclaim_stat;
|
|
|
|
recent_rotated[0] += rstat->recent_rotated[0];
|
|
recent_rotated[1] += rstat->recent_rotated[1];
|
|
recent_scanned[0] += rstat->recent_scanned[0];
|
|
recent_scanned[1] += rstat->recent_scanned[1];
|
|
}
|
|
seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]);
|
|
seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]);
|
|
seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]);
|
|
seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]);
|
|
}
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
return mem_cgroup_swappiness(memcg);
|
|
}
|
|
|
|
static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
if (val > 100)
|
|
return -EINVAL;
|
|
|
|
if (css->parent)
|
|
memcg->swappiness = val;
|
|
else
|
|
vm_swappiness = val;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
|
|
{
|
|
struct mem_cgroup_threshold_ary *t;
|
|
unsigned long usage;
|
|
int i;
|
|
|
|
rcu_read_lock();
|
|
if (!swap)
|
|
t = rcu_dereference(memcg->thresholds.primary);
|
|
else
|
|
t = rcu_dereference(memcg->memsw_thresholds.primary);
|
|
|
|
if (!t)
|
|
goto unlock;
|
|
|
|
usage = mem_cgroup_usage(memcg, swap);
|
|
|
|
/*
|
|
* current_threshold points to threshold just below or equal to usage.
|
|
* If it's not true, a threshold was crossed after last
|
|
* call of __mem_cgroup_threshold().
|
|
*/
|
|
i = t->current_threshold;
|
|
|
|
/*
|
|
* Iterate backward over array of thresholds starting from
|
|
* current_threshold and check if a threshold is crossed.
|
|
* If none of thresholds below usage is crossed, we read
|
|
* only one element of the array here.
|
|
*/
|
|
for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--)
|
|
eventfd_signal(t->entries[i].eventfd, 1);
|
|
|
|
/* i = current_threshold + 1 */
|
|
i++;
|
|
|
|
/*
|
|
* Iterate forward over array of thresholds starting from
|
|
* current_threshold+1 and check if a threshold is crossed.
|
|
* If none of thresholds above usage is crossed, we read
|
|
* only one element of the array here.
|
|
*/
|
|
for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++)
|
|
eventfd_signal(t->entries[i].eventfd, 1);
|
|
|
|
/* Update current_threshold */
|
|
t->current_threshold = i - 1;
|
|
unlock:
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void mem_cgroup_threshold(struct mem_cgroup *memcg)
|
|
{
|
|
while (memcg) {
|
|
__mem_cgroup_threshold(memcg, false);
|
|
if (do_swap_account)
|
|
__mem_cgroup_threshold(memcg, true);
|
|
|
|
memcg = parent_mem_cgroup(memcg);
|
|
}
|
|
}
|
|
|
|
static int compare_thresholds(const void *a, const void *b)
|
|
{
|
|
const struct mem_cgroup_threshold *_a = a;
|
|
const struct mem_cgroup_threshold *_b = b;
|
|
|
|
if (_a->threshold > _b->threshold)
|
|
return 1;
|
|
|
|
if (_a->threshold < _b->threshold)
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup_eventfd_list *ev;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
|
|
list_for_each_entry(ev, &memcg->oom_notify, list)
|
|
eventfd_signal(ev->eventfd, 1);
|
|
|
|
spin_unlock(&memcg_oom_lock);
|
|
return 0;
|
|
}
|
|
|
|
static void mem_cgroup_oom_notify(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
mem_cgroup_oom_notify_cb(iter);
|
|
}
|
|
|
|
static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd, const char *args, enum res_type type)
|
|
{
|
|
struct mem_cgroup_thresholds *thresholds;
|
|
struct mem_cgroup_threshold_ary *new;
|
|
unsigned long threshold;
|
|
unsigned long usage;
|
|
int i, size, ret;
|
|
|
|
ret = page_counter_memparse(args, &threshold);
|
|
if (ret)
|
|
return ret;
|
|
|
|
mutex_lock(&memcg->thresholds_lock);
|
|
|
|
if (type == _MEM) {
|
|
thresholds = &memcg->thresholds;
|
|
usage = mem_cgroup_usage(memcg, false);
|
|
} else if (type == _MEMSWAP) {
|
|
thresholds = &memcg->memsw_thresholds;
|
|
usage = mem_cgroup_usage(memcg, true);
|
|
} else
|
|
BUG();
|
|
|
|
/* Check if a threshold crossed before adding a new one */
|
|
if (thresholds->primary)
|
|
__mem_cgroup_threshold(memcg, type == _MEMSWAP);
|
|
|
|
size = thresholds->primary ? thresholds->primary->size + 1 : 1;
|
|
|
|
/* Allocate memory for new array of thresholds */
|
|
new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold),
|
|
GFP_KERNEL);
|
|
if (!new) {
|
|
ret = -ENOMEM;
|
|
goto unlock;
|
|
}
|
|
new->size = size;
|
|
|
|
/* Copy thresholds (if any) to new array */
|
|
if (thresholds->primary) {
|
|
memcpy(new->entries, thresholds->primary->entries, (size - 1) *
|
|
sizeof(struct mem_cgroup_threshold));
|
|
}
|
|
|
|
/* Add new threshold */
|
|
new->entries[size - 1].eventfd = eventfd;
|
|
new->entries[size - 1].threshold = threshold;
|
|
|
|
/* Sort thresholds. Registering of new threshold isn't time-critical */
|
|
sort(new->entries, size, sizeof(struct mem_cgroup_threshold),
|
|
compare_thresholds, NULL);
|
|
|
|
/* Find current threshold */
|
|
new->current_threshold = -1;
|
|
for (i = 0; i < size; i++) {
|
|
if (new->entries[i].threshold <= usage) {
|
|
/*
|
|
* new->current_threshold will not be used until
|
|
* rcu_assign_pointer(), so it's safe to increment
|
|
* it here.
|
|
*/
|
|
++new->current_threshold;
|
|
} else
|
|
break;
|
|
}
|
|
|
|
/* Free old spare buffer and save old primary buffer as spare */
|
|
kfree(thresholds->spare);
|
|
thresholds->spare = thresholds->primary;
|
|
|
|
rcu_assign_pointer(thresholds->primary, new);
|
|
|
|
/* To be sure that nobody uses thresholds */
|
|
synchronize_rcu();
|
|
|
|
unlock:
|
|
mutex_unlock(&memcg->thresholds_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd, const char *args)
|
|
{
|
|
return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEM);
|
|
}
|
|
|
|
static int memsw_cgroup_usage_register_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd, const char *args)
|
|
{
|
|
return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEMSWAP);
|
|
}
|
|
|
|
static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd, enum res_type type)
|
|
{
|
|
struct mem_cgroup_thresholds *thresholds;
|
|
struct mem_cgroup_threshold_ary *new;
|
|
unsigned long usage;
|
|
int i, j, size;
|
|
|
|
mutex_lock(&memcg->thresholds_lock);
|
|
|
|
if (type == _MEM) {
|
|
thresholds = &memcg->thresholds;
|
|
usage = mem_cgroup_usage(memcg, false);
|
|
} else if (type == _MEMSWAP) {
|
|
thresholds = &memcg->memsw_thresholds;
|
|
usage = mem_cgroup_usage(memcg, true);
|
|
} else
|
|
BUG();
|
|
|
|
if (!thresholds->primary)
|
|
goto unlock;
|
|
|
|
/* Check if a threshold crossed before removing */
|
|
__mem_cgroup_threshold(memcg, type == _MEMSWAP);
|
|
|
|
/* Calculate new number of threshold */
|
|
size = 0;
|
|
for (i = 0; i < thresholds->primary->size; i++) {
|
|
if (thresholds->primary->entries[i].eventfd != eventfd)
|
|
size++;
|
|
}
|
|
|
|
new = thresholds->spare;
|
|
|
|
/* Set thresholds array to NULL if we don't have thresholds */
|
|
if (!size) {
|
|
kfree(new);
|
|
new = NULL;
|
|
goto swap_buffers;
|
|
}
|
|
|
|
new->size = size;
|
|
|
|
/* Copy thresholds and find current threshold */
|
|
new->current_threshold = -1;
|
|
for (i = 0, j = 0; i < thresholds->primary->size; i++) {
|
|
if (thresholds->primary->entries[i].eventfd == eventfd)
|
|
continue;
|
|
|
|
new->entries[j] = thresholds->primary->entries[i];
|
|
if (new->entries[j].threshold <= usage) {
|
|
/*
|
|
* new->current_threshold will not be used
|
|
* until rcu_assign_pointer(), so it's safe to increment
|
|
* it here.
|
|
*/
|
|
++new->current_threshold;
|
|
}
|
|
j++;
|
|
}
|
|
|
|
swap_buffers:
|
|
/* Swap primary and spare array */
|
|
thresholds->spare = thresholds->primary;
|
|
/* If all events are unregistered, free the spare array */
|
|
if (!new) {
|
|
kfree(thresholds->spare);
|
|
thresholds->spare = NULL;
|
|
}
|
|
|
|
rcu_assign_pointer(thresholds->primary, new);
|
|
|
|
/* To be sure that nobody uses thresholds */
|
|
synchronize_rcu();
|
|
unlock:
|
|
mutex_unlock(&memcg->thresholds_lock);
|
|
}
|
|
|
|
static void mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd)
|
|
{
|
|
return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEM);
|
|
}
|
|
|
|
static void memsw_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd)
|
|
{
|
|
return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEMSWAP);
|
|
}
|
|
|
|
static int mem_cgroup_oom_register_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd, const char *args)
|
|
{
|
|
struct mem_cgroup_eventfd_list *event;
|
|
|
|
event = kmalloc(sizeof(*event), GFP_KERNEL);
|
|
if (!event)
|
|
return -ENOMEM;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
|
|
event->eventfd = eventfd;
|
|
list_add(&event->list, &memcg->oom_notify);
|
|
|
|
/* already in OOM ? */
|
|
if (atomic_read(&memcg->under_oom))
|
|
eventfd_signal(eventfd, 1);
|
|
spin_unlock(&memcg_oom_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void mem_cgroup_oom_unregister_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd)
|
|
{
|
|
struct mem_cgroup_eventfd_list *ev, *tmp;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
|
|
list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) {
|
|
if (ev->eventfd == eventfd) {
|
|
list_del(&ev->list);
|
|
kfree(ev);
|
|
}
|
|
}
|
|
|
|
spin_unlock(&memcg_oom_lock);
|
|
}
|
|
|
|
static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(sf));
|
|
|
|
seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable);
|
|
seq_printf(sf, "under_oom %d\n", (bool)atomic_read(&memcg->under_oom));
|
|
return 0;
|
|
}
|
|
|
|
static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
/* cannot set to root cgroup and only 0 and 1 are allowed */
|
|
if (!css->parent || !((val == 0) || (val == 1)))
|
|
return -EINVAL;
|
|
|
|
memcg->oom_kill_disable = val;
|
|
if (!val)
|
|
memcg_oom_recover(memcg);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
|
|
{
|
|
int ret;
|
|
|
|
ret = memcg_propagate_kmem(memcg);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return mem_cgroup_sockets_init(memcg, ss);
|
|
}
|
|
|
|
static void memcg_destroy_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
memcg_unregister_all_caches(memcg);
|
|
mem_cgroup_sockets_destroy(memcg);
|
|
}
|
|
#else
|
|
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void memcg_destroy_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* DO NOT USE IN NEW FILES.
|
|
*
|
|
* "cgroup.event_control" implementation.
|
|
*
|
|
* This is way over-engineered. It tries to support fully configurable
|
|
* events for each user. Such level of flexibility is completely
|
|
* unnecessary especially in the light of the planned unified hierarchy.
|
|
*
|
|
* Please deprecate this and replace with something simpler if at all
|
|
* possible.
|
|
*/
|
|
|
|
/*
|
|
* Unregister event and free resources.
|
|
*
|
|
* Gets called from workqueue.
|
|
*/
|
|
static void memcg_event_remove(struct work_struct *work)
|
|
{
|
|
struct mem_cgroup_event *event =
|
|
container_of(work, struct mem_cgroup_event, remove);
|
|
struct mem_cgroup *memcg = event->memcg;
|
|
|
|
remove_wait_queue(event->wqh, &event->wait);
|
|
|
|
event->unregister_event(memcg, event->eventfd);
|
|
|
|
/* Notify userspace the event is going away. */
|
|
eventfd_signal(event->eventfd, 1);
|
|
|
|
eventfd_ctx_put(event->eventfd);
|
|
kfree(event);
|
|
css_put(&memcg->css);
|
|
}
|
|
|
|
/*
|
|
* Gets called on POLLHUP on eventfd when user closes it.
|
|
*
|
|
* Called with wqh->lock held and interrupts disabled.
|
|
*/
|
|
static int memcg_event_wake(wait_queue_t *wait, unsigned mode,
|
|
int sync, void *key)
|
|
{
|
|
struct mem_cgroup_event *event =
|
|
container_of(wait, struct mem_cgroup_event, wait);
|
|
struct mem_cgroup *memcg = event->memcg;
|
|
unsigned long flags = (unsigned long)key;
|
|
|
|
if (flags & POLLHUP) {
|
|
/*
|
|
* If the event has been detached at cgroup removal, we
|
|
* can simply return knowing the other side will cleanup
|
|
* for us.
|
|
*
|
|
* We can't race against event freeing since the other
|
|
* side will require wqh->lock via remove_wait_queue(),
|
|
* which we hold.
|
|
*/
|
|
spin_lock(&memcg->event_list_lock);
|
|
if (!list_empty(&event->list)) {
|
|
list_del_init(&event->list);
|
|
/*
|
|
* We are in atomic context, but cgroup_event_remove()
|
|
* may sleep, so we have to call it in workqueue.
|
|
*/
|
|
schedule_work(&event->remove);
|
|
}
|
|
spin_unlock(&memcg->event_list_lock);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void memcg_event_ptable_queue_proc(struct file *file,
|
|
wait_queue_head_t *wqh, poll_table *pt)
|
|
{
|
|
struct mem_cgroup_event *event =
|
|
container_of(pt, struct mem_cgroup_event, pt);
|
|
|
|
event->wqh = wqh;
|
|
add_wait_queue(wqh, &event->wait);
|
|
}
|
|
|
|
/*
|
|
* DO NOT USE IN NEW FILES.
|
|
*
|
|
* Parse input and register new cgroup event handler.
|
|
*
|
|
* Input must be in format '<event_fd> <control_fd> <args>'.
|
|
* Interpretation of args is defined by control file implementation.
|
|
*/
|
|
static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
|
|
char *buf, size_t nbytes, loff_t off)
|
|
{
|
|
struct cgroup_subsys_state *css = of_css(of);
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup_event *event;
|
|
struct cgroup_subsys_state *cfile_css;
|
|
unsigned int efd, cfd;
|
|
struct fd efile;
|
|
struct fd cfile;
|
|
const char *name;
|
|
char *endp;
|
|
int ret;
|
|
|
|
buf = strstrip(buf);
|
|
|
|
efd = simple_strtoul(buf, &endp, 10);
|
|
if (*endp != ' ')
|
|
return -EINVAL;
|
|
buf = endp + 1;
|
|
|
|
cfd = simple_strtoul(buf, &endp, 10);
|
|
if ((*endp != ' ') && (*endp != '\0'))
|
|
return -EINVAL;
|
|
buf = endp + 1;
|
|
|
|
event = kzalloc(sizeof(*event), GFP_KERNEL);
|
|
if (!event)
|
|
return -ENOMEM;
|
|
|
|
event->memcg = memcg;
|
|
INIT_LIST_HEAD(&event->list);
|
|
init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc);
|
|
init_waitqueue_func_entry(&event->wait, memcg_event_wake);
|
|
INIT_WORK(&event->remove, memcg_event_remove);
|
|
|
|
efile = fdget(efd);
|
|
if (!efile.file) {
|
|
ret = -EBADF;
|
|
goto out_kfree;
|
|
}
|
|
|
|
event->eventfd = eventfd_ctx_fileget(efile.file);
|
|
if (IS_ERR(event->eventfd)) {
|
|
ret = PTR_ERR(event->eventfd);
|
|
goto out_put_efile;
|
|
}
|
|
|
|
cfile = fdget(cfd);
|
|
if (!cfile.file) {
|
|
ret = -EBADF;
|
|
goto out_put_eventfd;
|
|
}
|
|
|
|
/* the process need read permission on control file */
|
|
/* AV: shouldn't we check that it's been opened for read instead? */
|
|
ret = inode_permission(file_inode(cfile.file), MAY_READ);
|
|
if (ret < 0)
|
|
goto out_put_cfile;
|
|
|
|
/*
|
|
* Determine the event callbacks and set them in @event. This used
|
|
* to be done via struct cftype but cgroup core no longer knows
|
|
* about these events. The following is crude but the whole thing
|
|
* is for compatibility anyway.
|
|
*
|
|
* DO NOT ADD NEW FILES.
|
|
*/
|
|
name = cfile.file->f_path.dentry->d_name.name;
|
|
|
|
if (!strcmp(name, "memory.usage_in_bytes")) {
|
|
event->register_event = mem_cgroup_usage_register_event;
|
|
event->unregister_event = mem_cgroup_usage_unregister_event;
|
|
} else if (!strcmp(name, "memory.oom_control")) {
|
|
event->register_event = mem_cgroup_oom_register_event;
|
|
event->unregister_event = mem_cgroup_oom_unregister_event;
|
|
} else if (!strcmp(name, "memory.pressure_level")) {
|
|
event->register_event = vmpressure_register_event;
|
|
event->unregister_event = vmpressure_unregister_event;
|
|
} else if (!strcmp(name, "memory.memsw.usage_in_bytes")) {
|
|
event->register_event = memsw_cgroup_usage_register_event;
|
|
event->unregister_event = memsw_cgroup_usage_unregister_event;
|
|
} else {
|
|
ret = -EINVAL;
|
|
goto out_put_cfile;
|
|
}
|
|
|
|
/*
|
|
* Verify @cfile should belong to @css. Also, remaining events are
|
|
* automatically removed on cgroup destruction but the removal is
|
|
* asynchronous, so take an extra ref on @css.
|
|
*/
|
|
cfile_css = css_tryget_online_from_dir(cfile.file->f_path.dentry->d_parent,
|
|
&memory_cgrp_subsys);
|
|
ret = -EINVAL;
|
|
if (IS_ERR(cfile_css))
|
|
goto out_put_cfile;
|
|
if (cfile_css != css) {
|
|
css_put(cfile_css);
|
|
goto out_put_cfile;
|
|
}
|
|
|
|
ret = event->register_event(memcg, event->eventfd, buf);
|
|
if (ret)
|
|
goto out_put_css;
|
|
|
|
efile.file->f_op->poll(efile.file, &event->pt);
|
|
|
|
spin_lock(&memcg->event_list_lock);
|
|
list_add(&event->list, &memcg->event_list);
|
|
spin_unlock(&memcg->event_list_lock);
|
|
|
|
fdput(cfile);
|
|
fdput(efile);
|
|
|
|
return nbytes;
|
|
|
|
out_put_css:
|
|
css_put(css);
|
|
out_put_cfile:
|
|
fdput(cfile);
|
|
out_put_eventfd:
|
|
eventfd_ctx_put(event->eventfd);
|
|
out_put_efile:
|
|
fdput(efile);
|
|
out_kfree:
|
|
kfree(event);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct cftype mem_cgroup_files[] = {
|
|
{
|
|
.name = "usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "max_usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
|
|
.write = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
|
|
.write = mem_cgroup_write,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "soft_limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
|
|
.write = mem_cgroup_write,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "failcnt",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
|
|
.write = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "stat",
|
|
.seq_show = memcg_stat_show,
|
|
},
|
|
{
|
|
.name = "force_empty",
|
|
.write = mem_cgroup_force_empty_write,
|
|
},
|
|
{
|
|
.name = "use_hierarchy",
|
|
.write_u64 = mem_cgroup_hierarchy_write,
|
|
.read_u64 = mem_cgroup_hierarchy_read,
|
|
},
|
|
{
|
|
.name = "cgroup.event_control", /* XXX: for compat */
|
|
.write = memcg_write_event_control,
|
|
.flags = CFTYPE_NO_PREFIX,
|
|
.mode = S_IWUGO,
|
|
},
|
|
{
|
|
.name = "swappiness",
|
|
.read_u64 = mem_cgroup_swappiness_read,
|
|
.write_u64 = mem_cgroup_swappiness_write,
|
|
},
|
|
{
|
|
.name = "move_charge_at_immigrate",
|
|
.read_u64 = mem_cgroup_move_charge_read,
|
|
.write_u64 = mem_cgroup_move_charge_write,
|
|
},
|
|
{
|
|
.name = "oom_control",
|
|
.seq_show = mem_cgroup_oom_control_read,
|
|
.write_u64 = mem_cgroup_oom_control_write,
|
|
.private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
|
|
},
|
|
{
|
|
.name = "pressure_level",
|
|
},
|
|
#ifdef CONFIG_NUMA
|
|
{
|
|
.name = "numa_stat",
|
|
.seq_show = memcg_numa_stat_show,
|
|
},
|
|
#endif
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
{
|
|
.name = "kmem.limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT),
|
|
.write = mem_cgroup_write,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "kmem.usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_KMEM, RES_USAGE),
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "kmem.failcnt",
|
|
.private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT),
|
|
.write = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "kmem.max_usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE),
|
|
.write = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
#ifdef CONFIG_SLABINFO
|
|
{
|
|
.name = "kmem.slabinfo",
|
|
.seq_start = slab_start,
|
|
.seq_next = slab_next,
|
|
.seq_stop = slab_stop,
|
|
.seq_show = memcg_slab_show,
|
|
},
|
|
#endif
|
|
#endif
|
|
{ }, /* terminate */
|
|
};
|
|
|
|
#ifdef CONFIG_MEMCG_SWAP
|
|
static struct cftype memsw_cgroup_files[] = {
|
|
{
|
|
.name = "memsw.usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "memsw.max_usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
|
|
.write = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "memsw.limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
|
|
.write = mem_cgroup_write,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "memsw.failcnt",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
|
|
.write = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{ }, /* terminate */
|
|
};
|
|
#endif
|
|
static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
|
|
{
|
|
struct mem_cgroup_per_node *pn;
|
|
struct mem_cgroup_per_zone *mz;
|
|
int zone, tmp = node;
|
|
/*
|
|
* This routine is called against possible nodes.
|
|
* But it's BUG to call kmalloc() against offline node.
|
|
*
|
|
* TODO: this routine can waste much memory for nodes which will
|
|
* never be onlined. It's better to use memory hotplug callback
|
|
* function.
|
|
*/
|
|
if (!node_state(node, N_NORMAL_MEMORY))
|
|
tmp = -1;
|
|
pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
|
|
if (!pn)
|
|
return 1;
|
|
|
|
for (zone = 0; zone < MAX_NR_ZONES; zone++) {
|
|
mz = &pn->zoneinfo[zone];
|
|
lruvec_init(&mz->lruvec);
|
|
mz->usage_in_excess = 0;
|
|
mz->on_tree = false;
|
|
mz->memcg = memcg;
|
|
}
|
|
memcg->nodeinfo[node] = pn;
|
|
return 0;
|
|
}
|
|
|
|
static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
|
|
{
|
|
kfree(memcg->nodeinfo[node]);
|
|
}
|
|
|
|
static struct mem_cgroup *mem_cgroup_alloc(void)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
size_t size;
|
|
|
|
size = sizeof(struct mem_cgroup);
|
|
size += nr_node_ids * sizeof(struct mem_cgroup_per_node *);
|
|
|
|
memcg = kzalloc(size, GFP_KERNEL);
|
|
if (!memcg)
|
|
return NULL;
|
|
|
|
memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
|
|
if (!memcg->stat)
|
|
goto out_free;
|
|
spin_lock_init(&memcg->pcp_counter_lock);
|
|
return memcg;
|
|
|
|
out_free:
|
|
kfree(memcg);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* At destroying mem_cgroup, references from swap_cgroup can remain.
|
|
* (scanning all at force_empty is too costly...)
|
|
*
|
|
* Instead of clearing all references at force_empty, we remember
|
|
* the number of reference from swap_cgroup and free mem_cgroup when
|
|
* it goes down to 0.
|
|
*
|
|
* Removal of cgroup itself succeeds regardless of refs from swap.
|
|
*/
|
|
|
|
static void __mem_cgroup_free(struct mem_cgroup *memcg)
|
|
{
|
|
int node;
|
|
|
|
mem_cgroup_remove_from_trees(memcg);
|
|
|
|
for_each_node(node)
|
|
free_mem_cgroup_per_zone_info(memcg, node);
|
|
|
|
free_percpu(memcg->stat);
|
|
|
|
disarm_static_keys(memcg);
|
|
kfree(memcg);
|
|
}
|
|
|
|
/*
|
|
* Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
|
|
*/
|
|
struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
|
|
{
|
|
if (!memcg->memory.parent)
|
|
return NULL;
|
|
return mem_cgroup_from_counter(memcg->memory.parent, memory);
|
|
}
|
|
EXPORT_SYMBOL(parent_mem_cgroup);
|
|
|
|
static void __init mem_cgroup_soft_limit_tree_init(void)
|
|
{
|
|
struct mem_cgroup_tree_per_node *rtpn;
|
|
struct mem_cgroup_tree_per_zone *rtpz;
|
|
int tmp, node, zone;
|
|
|
|
for_each_node(node) {
|
|
tmp = node;
|
|
if (!node_state(node, N_NORMAL_MEMORY))
|
|
tmp = -1;
|
|
rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
|
|
BUG_ON(!rtpn);
|
|
|
|
soft_limit_tree.rb_tree_per_node[node] = rtpn;
|
|
|
|
for (zone = 0; zone < MAX_NR_ZONES; zone++) {
|
|
rtpz = &rtpn->rb_tree_per_zone[zone];
|
|
rtpz->rb_root = RB_ROOT;
|
|
spin_lock_init(&rtpz->lock);
|
|
}
|
|
}
|
|
}
|
|
|
|
static struct cgroup_subsys_state * __ref
|
|
mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
long error = -ENOMEM;
|
|
int node;
|
|
|
|
memcg = mem_cgroup_alloc();
|
|
if (!memcg)
|
|
return ERR_PTR(error);
|
|
|
|
for_each_node(node)
|
|
if (alloc_mem_cgroup_per_zone_info(memcg, node))
|
|
goto free_out;
|
|
|
|
/* root ? */
|
|
if (parent_css == NULL) {
|
|
root_mem_cgroup = memcg;
|
|
page_counter_init(&memcg->memory, NULL);
|
|
page_counter_init(&memcg->memsw, NULL);
|
|
page_counter_init(&memcg->kmem, NULL);
|
|
}
|
|
|
|
memcg->last_scanned_node = MAX_NUMNODES;
|
|
INIT_LIST_HEAD(&memcg->oom_notify);
|
|
memcg->move_charge_at_immigrate = 0;
|
|
mutex_init(&memcg->thresholds_lock);
|
|
spin_lock_init(&memcg->move_lock);
|
|
vmpressure_init(&memcg->vmpressure);
|
|
INIT_LIST_HEAD(&memcg->event_list);
|
|
spin_lock_init(&memcg->event_list_lock);
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
memcg->kmemcg_id = -1;
|
|
INIT_LIST_HEAD(&memcg->memcg_slab_caches);
|
|
#endif
|
|
|
|
return &memcg->css;
|
|
|
|
free_out:
|
|
__mem_cgroup_free(memcg);
|
|
return ERR_PTR(error);
|
|
}
|
|
|
|
static int
|
|
mem_cgroup_css_online(struct cgroup_subsys_state *css)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup *parent = mem_cgroup_from_css(css->parent);
|
|
int ret;
|
|
|
|
if (css->id > MEM_CGROUP_ID_MAX)
|
|
return -ENOSPC;
|
|
|
|
if (!parent)
|
|
return 0;
|
|
|
|
mutex_lock(&memcg_create_mutex);
|
|
|
|
memcg->use_hierarchy = parent->use_hierarchy;
|
|
memcg->oom_kill_disable = parent->oom_kill_disable;
|
|
memcg->swappiness = mem_cgroup_swappiness(parent);
|
|
|
|
if (parent->use_hierarchy) {
|
|
page_counter_init(&memcg->memory, &parent->memory);
|
|
page_counter_init(&memcg->memsw, &parent->memsw);
|
|
page_counter_init(&memcg->kmem, &parent->kmem);
|
|
|
|
/*
|
|
* No need to take a reference to the parent because cgroup
|
|
* core guarantees its existence.
|
|
*/
|
|
} else {
|
|
page_counter_init(&memcg->memory, NULL);
|
|
page_counter_init(&memcg->memsw, NULL);
|
|
page_counter_init(&memcg->kmem, NULL);
|
|
/*
|
|
* Deeper hierachy with use_hierarchy == false doesn't make
|
|
* much sense so let cgroup subsystem know about this
|
|
* unfortunate state in our controller.
|
|
*/
|
|
if (parent != root_mem_cgroup)
|
|
memory_cgrp_subsys.broken_hierarchy = true;
|
|
}
|
|
mutex_unlock(&memcg_create_mutex);
|
|
|
|
ret = memcg_init_kmem(memcg, &memory_cgrp_subsys);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/*
|
|
* Make sure the memcg is initialized: mem_cgroup_iter()
|
|
* orders reading memcg->initialized against its callers
|
|
* reading the memcg members.
|
|
*/
|
|
smp_store_release(&memcg->initialized, 1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup_event *event, *tmp;
|
|
|
|
/*
|
|
* Unregister events and notify userspace.
|
|
* Notify userspace about cgroup removing only after rmdir of cgroup
|
|
* directory to avoid race between userspace and kernelspace.
|
|
*/
|
|
spin_lock(&memcg->event_list_lock);
|
|
list_for_each_entry_safe(event, tmp, &memcg->event_list, list) {
|
|
list_del_init(&event->list);
|
|
schedule_work(&event->remove);
|
|
}
|
|
spin_unlock(&memcg->event_list_lock);
|
|
|
|
vmpressure_cleanup(&memcg->vmpressure);
|
|
}
|
|
|
|
static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
memcg_destroy_kmem(memcg);
|
|
__mem_cgroup_free(memcg);
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_css_reset - reset the states of a mem_cgroup
|
|
* @css: the target css
|
|
*
|
|
* Reset the states of the mem_cgroup associated with @css. This is
|
|
* invoked when the userland requests disabling on the default hierarchy
|
|
* but the memcg is pinned through dependency. The memcg should stop
|
|
* applying policies and should revert to the vanilla state as it may be
|
|
* made visible again.
|
|
*
|
|
* The current implementation only resets the essential configurations.
|
|
* This needs to be expanded to cover all the visible parts.
|
|
*/
|
|
static void mem_cgroup_css_reset(struct cgroup_subsys_state *css)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
mem_cgroup_resize_limit(memcg, PAGE_COUNTER_MAX);
|
|
mem_cgroup_resize_memsw_limit(memcg, PAGE_COUNTER_MAX);
|
|
memcg_update_kmem_limit(memcg, PAGE_COUNTER_MAX);
|
|
memcg->soft_limit = 0;
|
|
}
|
|
|
|
#ifdef CONFIG_MMU
|
|
/* Handlers for move charge at task migration. */
|
|
static int mem_cgroup_do_precharge(unsigned long count)
|
|
{
|
|
int ret;
|
|
|
|
/* Try a single bulk charge without reclaim first */
|
|
ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_WAIT, count);
|
|
if (!ret) {
|
|
mc.precharge += count;
|
|
return ret;
|
|
}
|
|
if (ret == -EINTR) {
|
|
cancel_charge(root_mem_cgroup, count);
|
|
return ret;
|
|
}
|
|
|
|
/* Try charges one by one with reclaim */
|
|
while (count--) {
|
|
ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_NORETRY, 1);
|
|
/*
|
|
* In case of failure, any residual charges against
|
|
* mc.to will be dropped by mem_cgroup_clear_mc()
|
|
* later on. However, cancel any charges that are
|
|
* bypassed to root right away or they'll be lost.
|
|
*/
|
|
if (ret == -EINTR)
|
|
cancel_charge(root_mem_cgroup, 1);
|
|
if (ret)
|
|
return ret;
|
|
mc.precharge++;
|
|
cond_resched();
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* get_mctgt_type - get target type of moving charge
|
|
* @vma: the vma the pte to be checked belongs
|
|
* @addr: the address corresponding to the pte to be checked
|
|
* @ptent: the pte to be checked
|
|
* @target: the pointer the target page or swap ent will be stored(can be NULL)
|
|
*
|
|
* Returns
|
|
* 0(MC_TARGET_NONE): if the pte is not a target for move charge.
|
|
* 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
|
|
* move charge. if @target is not NULL, the page is stored in target->page
|
|
* with extra refcnt got(Callers should handle it).
|
|
* 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
|
|
* target for charge migration. if @target is not NULL, the entry is stored
|
|
* in target->ent.
|
|
*
|
|
* Called with pte lock held.
|
|
*/
|
|
union mc_target {
|
|
struct page *page;
|
|
swp_entry_t ent;
|
|
};
|
|
|
|
enum mc_target_type {
|
|
MC_TARGET_NONE = 0,
|
|
MC_TARGET_PAGE,
|
|
MC_TARGET_SWAP,
|
|
};
|
|
|
|
static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent)
|
|
{
|
|
struct page *page = vm_normal_page(vma, addr, ptent);
|
|
|
|
if (!page || !page_mapped(page))
|
|
return NULL;
|
|
if (PageAnon(page)) {
|
|
/* we don't move shared anon */
|
|
if (!move_anon())
|
|
return NULL;
|
|
} else if (!move_file())
|
|
/* we ignore mapcount for file pages */
|
|
return NULL;
|
|
if (!get_page_unless_zero(page))
|
|
return NULL;
|
|
|
|
return page;
|
|
}
|
|
|
|
#ifdef CONFIG_SWAP
|
|
static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent, swp_entry_t *entry)
|
|
{
|
|
struct page *page = NULL;
|
|
swp_entry_t ent = pte_to_swp_entry(ptent);
|
|
|
|
if (!move_anon() || non_swap_entry(ent))
|
|
return NULL;
|
|
/*
|
|
* Because lookup_swap_cache() updates some statistics counter,
|
|
* we call find_get_page() with swapper_space directly.
|
|
*/
|
|
page = find_get_page(swap_address_space(ent), ent.val);
|
|
if (do_swap_account)
|
|
entry->val = ent.val;
|
|
|
|
return page;
|
|
}
|
|
#else
|
|
static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent, swp_entry_t *entry)
|
|
{
|
|
return NULL;
|
|
}
|
|
#endif
|
|
|
|
static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent, swp_entry_t *entry)
|
|
{
|
|
struct page *page = NULL;
|
|
struct address_space *mapping;
|
|
pgoff_t pgoff;
|
|
|
|
if (!vma->vm_file) /* anonymous vma */
|
|
return NULL;
|
|
if (!move_file())
|
|
return NULL;
|
|
|
|
mapping = vma->vm_file->f_mapping;
|
|
if (pte_none(ptent))
|
|
pgoff = linear_page_index(vma, addr);
|
|
else /* pte_file(ptent) is true */
|
|
pgoff = pte_to_pgoff(ptent);
|
|
|
|
/* page is moved even if it's not RSS of this task(page-faulted). */
|
|
#ifdef CONFIG_SWAP
|
|
/* shmem/tmpfs may report page out on swap: account for that too. */
|
|
if (shmem_mapping(mapping)) {
|
|
page = find_get_entry(mapping, pgoff);
|
|
if (radix_tree_exceptional_entry(page)) {
|
|
swp_entry_t swp = radix_to_swp_entry(page);
|
|
if (do_swap_account)
|
|
*entry = swp;
|
|
page = find_get_page(swap_address_space(swp), swp.val);
|
|
}
|
|
} else
|
|
page = find_get_page(mapping, pgoff);
|
|
#else
|
|
page = find_get_page(mapping, pgoff);
|
|
#endif
|
|
return page;
|
|
}
|
|
|
|
static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent, union mc_target *target)
|
|
{
|
|
struct page *page = NULL;
|
|
enum mc_target_type ret = MC_TARGET_NONE;
|
|
swp_entry_t ent = { .val = 0 };
|
|
|
|
if (pte_present(ptent))
|
|
page = mc_handle_present_pte(vma, addr, ptent);
|
|
else if (is_swap_pte(ptent))
|
|
page = mc_handle_swap_pte(vma, addr, ptent, &ent);
|
|
else if (pte_none(ptent) || pte_file(ptent))
|
|
page = mc_handle_file_pte(vma, addr, ptent, &ent);
|
|
|
|
if (!page && !ent.val)
|
|
return ret;
|
|
if (page) {
|
|
/*
|
|
* Do only loose check w/o serialization.
|
|
* mem_cgroup_move_account() checks the page is valid or
|
|
* not under LRU exclusion.
|
|
*/
|
|
if (page->mem_cgroup == mc.from) {
|
|
ret = MC_TARGET_PAGE;
|
|
if (target)
|
|
target->page = page;
|
|
}
|
|
if (!ret || !target)
|
|
put_page(page);
|
|
}
|
|
/* There is a swap entry and a page doesn't exist or isn't charged */
|
|
if (ent.val && !ret &&
|
|
mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) {
|
|
ret = MC_TARGET_SWAP;
|
|
if (target)
|
|
target->ent = ent;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
/*
|
|
* We don't consider swapping or file mapped pages because THP does not
|
|
* support them for now.
|
|
* Caller should make sure that pmd_trans_huge(pmd) is true.
|
|
*/
|
|
static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
|
|
unsigned long addr, pmd_t pmd, union mc_target *target)
|
|
{
|
|
struct page *page = NULL;
|
|
enum mc_target_type ret = MC_TARGET_NONE;
|
|
|
|
page = pmd_page(pmd);
|
|
VM_BUG_ON_PAGE(!page || !PageHead(page), page);
|
|
if (!move_anon())
|
|
return ret;
|
|
if (page->mem_cgroup == mc.from) {
|
|
ret = MC_TARGET_PAGE;
|
|
if (target) {
|
|
get_page(page);
|
|
target->page = page;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
#else
|
|
static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
|
|
unsigned long addr, pmd_t pmd, union mc_target *target)
|
|
{
|
|
return MC_TARGET_NONE;
|
|
}
|
|
#endif
|
|
|
|
static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
|
|
unsigned long addr, unsigned long end,
|
|
struct mm_walk *walk)
|
|
{
|
|
struct vm_area_struct *vma = walk->private;
|
|
pte_t *pte;
|
|
spinlock_t *ptl;
|
|
|
|
if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
|
|
if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE)
|
|
mc.precharge += HPAGE_PMD_NR;
|
|
spin_unlock(ptl);
|
|
return 0;
|
|
}
|
|
|
|
if (pmd_trans_unstable(pmd))
|
|
return 0;
|
|
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
|
|
for (; addr != end; pte++, addr += PAGE_SIZE)
|
|
if (get_mctgt_type(vma, addr, *pte, NULL))
|
|
mc.precharge++; /* increment precharge temporarily */
|
|
pte_unmap_unlock(pte - 1, ptl);
|
|
cond_resched();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
|
|
{
|
|
unsigned long precharge;
|
|
struct vm_area_struct *vma;
|
|
|
|
down_read(&mm->mmap_sem);
|
|
for (vma = mm->mmap; vma; vma = vma->vm_next) {
|
|
struct mm_walk mem_cgroup_count_precharge_walk = {
|
|
.pmd_entry = mem_cgroup_count_precharge_pte_range,
|
|
.mm = mm,
|
|
.private = vma,
|
|
};
|
|
if (is_vm_hugetlb_page(vma))
|
|
continue;
|
|
walk_page_range(vma->vm_start, vma->vm_end,
|
|
&mem_cgroup_count_precharge_walk);
|
|
}
|
|
up_read(&mm->mmap_sem);
|
|
|
|
precharge = mc.precharge;
|
|
mc.precharge = 0;
|
|
|
|
return precharge;
|
|
}
|
|
|
|
static int mem_cgroup_precharge_mc(struct mm_struct *mm)
|
|
{
|
|
unsigned long precharge = mem_cgroup_count_precharge(mm);
|
|
|
|
VM_BUG_ON(mc.moving_task);
|
|
mc.moving_task = current;
|
|
return mem_cgroup_do_precharge(precharge);
|
|
}
|
|
|
|
/* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
|
|
static void __mem_cgroup_clear_mc(void)
|
|
{
|
|
struct mem_cgroup *from = mc.from;
|
|
struct mem_cgroup *to = mc.to;
|
|
|
|
/* we must uncharge all the leftover precharges from mc.to */
|
|
if (mc.precharge) {
|
|
cancel_charge(mc.to, mc.precharge);
|
|
mc.precharge = 0;
|
|
}
|
|
/*
|
|
* we didn't uncharge from mc.from at mem_cgroup_move_account(), so
|
|
* we must uncharge here.
|
|
*/
|
|
if (mc.moved_charge) {
|
|
cancel_charge(mc.from, mc.moved_charge);
|
|
mc.moved_charge = 0;
|
|
}
|
|
/* we must fixup refcnts and charges */
|
|
if (mc.moved_swap) {
|
|
/* uncharge swap account from the old cgroup */
|
|
if (!mem_cgroup_is_root(mc.from))
|
|
page_counter_uncharge(&mc.from->memsw, mc.moved_swap);
|
|
|
|
/*
|
|
* we charged both to->memory and to->memsw, so we
|
|
* should uncharge to->memory.
|
|
*/
|
|
if (!mem_cgroup_is_root(mc.to))
|
|
page_counter_uncharge(&mc.to->memory, mc.moved_swap);
|
|
|
|
css_put_many(&mc.from->css, mc.moved_swap);
|
|
|
|
/* we've already done css_get(mc.to) */
|
|
mc.moved_swap = 0;
|
|
}
|
|
memcg_oom_recover(from);
|
|
memcg_oom_recover(to);
|
|
wake_up_all(&mc.waitq);
|
|
}
|
|
|
|
static void mem_cgroup_clear_mc(void)
|
|
{
|
|
/*
|
|
* we must clear moving_task before waking up waiters at the end of
|
|
* task migration.
|
|
*/
|
|
mc.moving_task = NULL;
|
|
__mem_cgroup_clear_mc();
|
|
spin_lock(&mc.lock);
|
|
mc.from = NULL;
|
|
mc.to = NULL;
|
|
spin_unlock(&mc.lock);
|
|
}
|
|
|
|
static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
struct task_struct *p = cgroup_taskset_first(tset);
|
|
int ret = 0;
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
unsigned long move_charge_at_immigrate;
|
|
|
|
/*
|
|
* We are now commited to this value whatever it is. Changes in this
|
|
* tunable will only affect upcoming migrations, not the current one.
|
|
* So we need to save it, and keep it going.
|
|
*/
|
|
move_charge_at_immigrate = memcg->move_charge_at_immigrate;
|
|
if (move_charge_at_immigrate) {
|
|
struct mm_struct *mm;
|
|
struct mem_cgroup *from = mem_cgroup_from_task(p);
|
|
|
|
VM_BUG_ON(from == memcg);
|
|
|
|
mm = get_task_mm(p);
|
|
if (!mm)
|
|
return 0;
|
|
/* We move charges only when we move a owner of the mm */
|
|
if (mm->owner == p) {
|
|
VM_BUG_ON(mc.from);
|
|
VM_BUG_ON(mc.to);
|
|
VM_BUG_ON(mc.precharge);
|
|
VM_BUG_ON(mc.moved_charge);
|
|
VM_BUG_ON(mc.moved_swap);
|
|
|
|
spin_lock(&mc.lock);
|
|
mc.from = from;
|
|
mc.to = memcg;
|
|
mc.immigrate_flags = move_charge_at_immigrate;
|
|
spin_unlock(&mc.lock);
|
|
/* We set mc.moving_task later */
|
|
|
|
ret = mem_cgroup_precharge_mc(mm);
|
|
if (ret)
|
|
mem_cgroup_clear_mc();
|
|
}
|
|
mmput(mm);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
if (mc.to)
|
|
mem_cgroup_clear_mc();
|
|
}
|
|
|
|
static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
|
|
unsigned long addr, unsigned long end,
|
|
struct mm_walk *walk)
|
|
{
|
|
int ret = 0;
|
|
struct vm_area_struct *vma = walk->private;
|
|
pte_t *pte;
|
|
spinlock_t *ptl;
|
|
enum mc_target_type target_type;
|
|
union mc_target target;
|
|
struct page *page;
|
|
|
|
/*
|
|
* We don't take compound_lock() here but no race with splitting thp
|
|
* happens because:
|
|
* - if pmd_trans_huge_lock() returns 1, the relevant thp is not
|
|
* under splitting, which means there's no concurrent thp split,
|
|
* - if another thread runs into split_huge_page() just after we
|
|
* entered this if-block, the thread must wait for page table lock
|
|
* to be unlocked in __split_huge_page_splitting(), where the main
|
|
* part of thp split is not executed yet.
|
|
*/
|
|
if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
|
|
if (mc.precharge < HPAGE_PMD_NR) {
|
|
spin_unlock(ptl);
|
|
return 0;
|
|
}
|
|
target_type = get_mctgt_type_thp(vma, addr, *pmd, &target);
|
|
if (target_type == MC_TARGET_PAGE) {
|
|
page = target.page;
|
|
if (!isolate_lru_page(page)) {
|
|
if (!mem_cgroup_move_account(page, HPAGE_PMD_NR,
|
|
mc.from, mc.to)) {
|
|
mc.precharge -= HPAGE_PMD_NR;
|
|
mc.moved_charge += HPAGE_PMD_NR;
|
|
}
|
|
putback_lru_page(page);
|
|
}
|
|
put_page(page);
|
|
}
|
|
spin_unlock(ptl);
|
|
return 0;
|
|
}
|
|
|
|
if (pmd_trans_unstable(pmd))
|
|
return 0;
|
|
retry:
|
|
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
|
|
for (; addr != end; addr += PAGE_SIZE) {
|
|
pte_t ptent = *(pte++);
|
|
swp_entry_t ent;
|
|
|
|
if (!mc.precharge)
|
|
break;
|
|
|
|
switch (get_mctgt_type(vma, addr, ptent, &target)) {
|
|
case MC_TARGET_PAGE:
|
|
page = target.page;
|
|
if (isolate_lru_page(page))
|
|
goto put;
|
|
if (!mem_cgroup_move_account(page, 1, mc.from, mc.to)) {
|
|
mc.precharge--;
|
|
/* we uncharge from mc.from later. */
|
|
mc.moved_charge++;
|
|
}
|
|
putback_lru_page(page);
|
|
put: /* get_mctgt_type() gets the page */
|
|
put_page(page);
|
|
break;
|
|
case MC_TARGET_SWAP:
|
|
ent = target.ent;
|
|
if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) {
|
|
mc.precharge--;
|
|
/* we fixup refcnts and charges later. */
|
|
mc.moved_swap++;
|
|
}
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
pte_unmap_unlock(pte - 1, ptl);
|
|
cond_resched();
|
|
|
|
if (addr != end) {
|
|
/*
|
|
* We have consumed all precharges we got in can_attach().
|
|
* We try charge one by one, but don't do any additional
|
|
* charges to mc.to if we have failed in charge once in attach()
|
|
* phase.
|
|
*/
|
|
ret = mem_cgroup_do_precharge(1);
|
|
if (!ret)
|
|
goto retry;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void mem_cgroup_move_charge(struct mm_struct *mm)
|
|
{
|
|
struct vm_area_struct *vma;
|
|
|
|
lru_add_drain_all();
|
|
/*
|
|
* Signal mem_cgroup_begin_page_stat() to take the memcg's
|
|
* move_lock while we're moving its pages to another memcg.
|
|
* Then wait for already started RCU-only updates to finish.
|
|
*/
|
|
atomic_inc(&mc.from->moving_account);
|
|
synchronize_rcu();
|
|
retry:
|
|
if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
|
|
/*
|
|
* Someone who are holding the mmap_sem might be waiting in
|
|
* waitq. So we cancel all extra charges, wake up all waiters,
|
|
* and retry. Because we cancel precharges, we might not be able
|
|
* to move enough charges, but moving charge is a best-effort
|
|
* feature anyway, so it wouldn't be a big problem.
|
|
*/
|
|
__mem_cgroup_clear_mc();
|
|
cond_resched();
|
|
goto retry;
|
|
}
|
|
for (vma = mm->mmap; vma; vma = vma->vm_next) {
|
|
int ret;
|
|
struct mm_walk mem_cgroup_move_charge_walk = {
|
|
.pmd_entry = mem_cgroup_move_charge_pte_range,
|
|
.mm = mm,
|
|
.private = vma,
|
|
};
|
|
if (is_vm_hugetlb_page(vma))
|
|
continue;
|
|
ret = walk_page_range(vma->vm_start, vma->vm_end,
|
|
&mem_cgroup_move_charge_walk);
|
|
if (ret)
|
|
/*
|
|
* means we have consumed all precharges and failed in
|
|
* doing additional charge. Just abandon here.
|
|
*/
|
|
break;
|
|
}
|
|
up_read(&mm->mmap_sem);
|
|
atomic_dec(&mc.from->moving_account);
|
|
}
|
|
|
|
static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
struct task_struct *p = cgroup_taskset_first(tset);
|
|
struct mm_struct *mm = get_task_mm(p);
|
|
|
|
if (mm) {
|
|
if (mc.to)
|
|
mem_cgroup_move_charge(mm);
|
|
mmput(mm);
|
|
}
|
|
if (mc.to)
|
|
mem_cgroup_clear_mc();
|
|
}
|
|
#else /* !CONFIG_MMU */
|
|
static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
return 0;
|
|
}
|
|
static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
}
|
|
static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Cgroup retains root cgroups across [un]mount cycles making it necessary
|
|
* to verify whether we're attached to the default hierarchy on each mount
|
|
* attempt.
|
|
*/
|
|
static void mem_cgroup_bind(struct cgroup_subsys_state *root_css)
|
|
{
|
|
/*
|
|
* use_hierarchy is forced on the default hierarchy. cgroup core
|
|
* guarantees that @root doesn't have any children, so turning it
|
|
* on for the root memcg is enough.
|
|
*/
|
|
if (cgroup_on_dfl(root_css->cgroup))
|
|
mem_cgroup_from_css(root_css)->use_hierarchy = true;
|
|
}
|
|
|
|
struct cgroup_subsys memory_cgrp_subsys = {
|
|
.css_alloc = mem_cgroup_css_alloc,
|
|
.css_online = mem_cgroup_css_online,
|
|
.css_offline = mem_cgroup_css_offline,
|
|
.css_free = mem_cgroup_css_free,
|
|
.css_reset = mem_cgroup_css_reset,
|
|
.can_attach = mem_cgroup_can_attach,
|
|
.cancel_attach = mem_cgroup_cancel_attach,
|
|
.attach = mem_cgroup_move_task,
|
|
.bind = mem_cgroup_bind,
|
|
.legacy_cftypes = mem_cgroup_files,
|
|
.early_init = 0,
|
|
};
|
|
|
|
#ifdef CONFIG_MEMCG_SWAP
|
|
static int __init enable_swap_account(char *s)
|
|
{
|
|
if (!strcmp(s, "1"))
|
|
really_do_swap_account = 1;
|
|
else if (!strcmp(s, "0"))
|
|
really_do_swap_account = 0;
|
|
return 1;
|
|
}
|
|
__setup("swapaccount=", enable_swap_account);
|
|
|
|
static void __init memsw_file_init(void)
|
|
{
|
|
WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys,
|
|
memsw_cgroup_files));
|
|
}
|
|
|
|
static void __init enable_swap_cgroup(void)
|
|
{
|
|
if (!mem_cgroup_disabled() && really_do_swap_account) {
|
|
do_swap_account = 1;
|
|
memsw_file_init();
|
|
}
|
|
}
|
|
|
|
#else
|
|
static void __init enable_swap_cgroup(void)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_MEMCG_SWAP
|
|
/**
|
|
* mem_cgroup_swapout - transfer a memsw charge to swap
|
|
* @page: page whose memsw charge to transfer
|
|
* @entry: swap entry to move the charge to
|
|
*
|
|
* Transfer the memsw charge of @page to @entry.
|
|
*/
|
|
void mem_cgroup_swapout(struct page *page, swp_entry_t entry)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
unsigned short oldid;
|
|
|
|
VM_BUG_ON_PAGE(PageLRU(page), page);
|
|
VM_BUG_ON_PAGE(page_count(page), page);
|
|
|
|
if (!do_swap_account)
|
|
return;
|
|
|
|
memcg = page->mem_cgroup;
|
|
|
|
/* Readahead page, never charged */
|
|
if (!memcg)
|
|
return;
|
|
|
|
oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg));
|
|
VM_BUG_ON_PAGE(oldid, page);
|
|
mem_cgroup_swap_statistics(memcg, true);
|
|
|
|
page->mem_cgroup = NULL;
|
|
|
|
if (!mem_cgroup_is_root(memcg))
|
|
page_counter_uncharge(&memcg->memory, 1);
|
|
|
|
/* XXX: caller holds IRQ-safe mapping->tree_lock */
|
|
VM_BUG_ON(!irqs_disabled());
|
|
|
|
mem_cgroup_charge_statistics(memcg, page, -1);
|
|
memcg_check_events(memcg, page);
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_uncharge_swap - uncharge a swap entry
|
|
* @entry: swap entry to uncharge
|
|
*
|
|
* Drop the memsw charge associated with @entry.
|
|
*/
|
|
void mem_cgroup_uncharge_swap(swp_entry_t entry)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
unsigned short id;
|
|
|
|
if (!do_swap_account)
|
|
return;
|
|
|
|
id = swap_cgroup_record(entry, 0);
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_lookup(id);
|
|
if (memcg) {
|
|
if (!mem_cgroup_is_root(memcg))
|
|
page_counter_uncharge(&memcg->memsw, 1);
|
|
mem_cgroup_swap_statistics(memcg, false);
|
|
css_put(&memcg->css);
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* mem_cgroup_try_charge - try charging a page
|
|
* @page: page to charge
|
|
* @mm: mm context of the victim
|
|
* @gfp_mask: reclaim mode
|
|
* @memcgp: charged memcg return
|
|
*
|
|
* Try to charge @page to the memcg that @mm belongs to, reclaiming
|
|
* pages according to @gfp_mask if necessary.
|
|
*
|
|
* Returns 0 on success, with *@memcgp pointing to the charged memcg.
|
|
* Otherwise, an error code is returned.
|
|
*
|
|
* After page->mapping has been set up, the caller must finalize the
|
|
* charge with mem_cgroup_commit_charge(). Or abort the transaction
|
|
* with mem_cgroup_cancel_charge() in case page instantiation fails.
|
|
*/
|
|
int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
|
|
gfp_t gfp_mask, struct mem_cgroup **memcgp)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
unsigned int nr_pages = 1;
|
|
int ret = 0;
|
|
|
|
if (mem_cgroup_disabled())
|
|
goto out;
|
|
|
|
if (PageSwapCache(page)) {
|
|
/*
|
|
* Every swap fault against a single page tries to charge the
|
|
* page, bail as early as possible. shmem_unuse() encounters
|
|
* already charged pages, too. The USED bit is protected by
|
|
* the page lock, which serializes swap cache removal, which
|
|
* in turn serializes uncharging.
|
|
*/
|
|
if (page->mem_cgroup)
|
|
goto out;
|
|
}
|
|
|
|
if (PageTransHuge(page)) {
|
|
nr_pages <<= compound_order(page);
|
|
VM_BUG_ON_PAGE(!PageTransHuge(page), page);
|
|
}
|
|
|
|
if (do_swap_account && PageSwapCache(page))
|
|
memcg = try_get_mem_cgroup_from_page(page);
|
|
if (!memcg)
|
|
memcg = get_mem_cgroup_from_mm(mm);
|
|
|
|
ret = try_charge(memcg, gfp_mask, nr_pages);
|
|
|
|
css_put(&memcg->css);
|
|
|
|
if (ret == -EINTR) {
|
|
memcg = root_mem_cgroup;
|
|
ret = 0;
|
|
}
|
|
out:
|
|
*memcgp = memcg;
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_commit_charge - commit a page charge
|
|
* @page: page to charge
|
|
* @memcg: memcg to charge the page to
|
|
* @lrucare: page might be on LRU already
|
|
*
|
|
* Finalize a charge transaction started by mem_cgroup_try_charge(),
|
|
* after page->mapping has been set up. This must happen atomically
|
|
* as part of the page instantiation, i.e. under the page table lock
|
|
* for anonymous pages, under the page lock for page and swap cache.
|
|
*
|
|
* In addition, the page must not be on the LRU during the commit, to
|
|
* prevent racing with task migration. If it might be, use @lrucare.
|
|
*
|
|
* Use mem_cgroup_cancel_charge() to cancel the transaction instead.
|
|
*/
|
|
void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,
|
|
bool lrucare)
|
|
{
|
|
unsigned int nr_pages = 1;
|
|
|
|
VM_BUG_ON_PAGE(!page->mapping, page);
|
|
VM_BUG_ON_PAGE(PageLRU(page) && !lrucare, page);
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
/*
|
|
* Swap faults will attempt to charge the same page multiple
|
|
* times. But reuse_swap_page() might have removed the page
|
|
* from swapcache already, so we can't check PageSwapCache().
|
|
*/
|
|
if (!memcg)
|
|
return;
|
|
|
|
commit_charge(page, memcg, lrucare);
|
|
|
|
if (PageTransHuge(page)) {
|
|
nr_pages <<= compound_order(page);
|
|
VM_BUG_ON_PAGE(!PageTransHuge(page), page);
|
|
}
|
|
|
|
local_irq_disable();
|
|
mem_cgroup_charge_statistics(memcg, page, nr_pages);
|
|
memcg_check_events(memcg, page);
|
|
local_irq_enable();
|
|
|
|
if (do_swap_account && PageSwapCache(page)) {
|
|
swp_entry_t entry = { .val = page_private(page) };
|
|
/*
|
|
* The swap entry might not get freed for a long time,
|
|
* let's not wait for it. The page already received a
|
|
* memory+swap charge, drop the swap entry duplicate.
|
|
*/
|
|
mem_cgroup_uncharge_swap(entry);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_cancel_charge - cancel a page charge
|
|
* @page: page to charge
|
|
* @memcg: memcg to charge the page to
|
|
*
|
|
* Cancel a charge transaction started by mem_cgroup_try_charge().
|
|
*/
|
|
void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg)
|
|
{
|
|
unsigned int nr_pages = 1;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
/*
|
|
* Swap faults will attempt to charge the same page multiple
|
|
* times. But reuse_swap_page() might have removed the page
|
|
* from swapcache already, so we can't check PageSwapCache().
|
|
*/
|
|
if (!memcg)
|
|
return;
|
|
|
|
if (PageTransHuge(page)) {
|
|
nr_pages <<= compound_order(page);
|
|
VM_BUG_ON_PAGE(!PageTransHuge(page), page);
|
|
}
|
|
|
|
cancel_charge(memcg, nr_pages);
|
|
}
|
|
|
|
static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout,
|
|
unsigned long nr_anon, unsigned long nr_file,
|
|
unsigned long nr_huge, struct page *dummy_page)
|
|
{
|
|
unsigned long nr_pages = nr_anon + nr_file;
|
|
unsigned long flags;
|
|
|
|
if (!mem_cgroup_is_root(memcg)) {
|
|
page_counter_uncharge(&memcg->memory, nr_pages);
|
|
if (do_swap_account)
|
|
page_counter_uncharge(&memcg->memsw, nr_pages);
|
|
memcg_oom_recover(memcg);
|
|
}
|
|
|
|
local_irq_save(flags);
|
|
__this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS], nr_anon);
|
|
__this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_CACHE], nr_file);
|
|
__this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], nr_huge);
|
|
__this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT], pgpgout);
|
|
__this_cpu_add(memcg->stat->nr_page_events, nr_pages);
|
|
memcg_check_events(memcg, dummy_page);
|
|
local_irq_restore(flags);
|
|
|
|
if (!mem_cgroup_is_root(memcg))
|
|
css_put_many(&memcg->css, nr_pages);
|
|
}
|
|
|
|
static void uncharge_list(struct list_head *page_list)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
unsigned long nr_anon = 0;
|
|
unsigned long nr_file = 0;
|
|
unsigned long nr_huge = 0;
|
|
unsigned long pgpgout = 0;
|
|
struct list_head *next;
|
|
struct page *page;
|
|
|
|
next = page_list->next;
|
|
do {
|
|
unsigned int nr_pages = 1;
|
|
|
|
page = list_entry(next, struct page, lru);
|
|
next = page->lru.next;
|
|
|
|
VM_BUG_ON_PAGE(PageLRU(page), page);
|
|
VM_BUG_ON_PAGE(page_count(page), page);
|
|
|
|
if (!page->mem_cgroup)
|
|
continue;
|
|
|
|
/*
|
|
* Nobody should be changing or seriously looking at
|
|
* page->mem_cgroup at this point, we have fully
|
|
* exclusive access to the page.
|
|
*/
|
|
|
|
if (memcg != page->mem_cgroup) {
|
|
if (memcg) {
|
|
uncharge_batch(memcg, pgpgout, nr_anon, nr_file,
|
|
nr_huge, page);
|
|
pgpgout = nr_anon = nr_file = nr_huge = 0;
|
|
}
|
|
memcg = page->mem_cgroup;
|
|
}
|
|
|
|
if (PageTransHuge(page)) {
|
|
nr_pages <<= compound_order(page);
|
|
VM_BUG_ON_PAGE(!PageTransHuge(page), page);
|
|
nr_huge += nr_pages;
|
|
}
|
|
|
|
if (PageAnon(page))
|
|
nr_anon += nr_pages;
|
|
else
|
|
nr_file += nr_pages;
|
|
|
|
page->mem_cgroup = NULL;
|
|
|
|
pgpgout++;
|
|
} while (next != page_list);
|
|
|
|
if (memcg)
|
|
uncharge_batch(memcg, pgpgout, nr_anon, nr_file,
|
|
nr_huge, page);
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_uncharge - uncharge a page
|
|
* @page: page to uncharge
|
|
*
|
|
* Uncharge a page previously charged with mem_cgroup_try_charge() and
|
|
* mem_cgroup_commit_charge().
|
|
*/
|
|
void mem_cgroup_uncharge(struct page *page)
|
|
{
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
/* Don't touch page->lru of any random page, pre-check: */
|
|
if (!page->mem_cgroup)
|
|
return;
|
|
|
|
INIT_LIST_HEAD(&page->lru);
|
|
uncharge_list(&page->lru);
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_uncharge_list - uncharge a list of page
|
|
* @page_list: list of pages to uncharge
|
|
*
|
|
* Uncharge a list of pages previously charged with
|
|
* mem_cgroup_try_charge() and mem_cgroup_commit_charge().
|
|
*/
|
|
void mem_cgroup_uncharge_list(struct list_head *page_list)
|
|
{
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
if (!list_empty(page_list))
|
|
uncharge_list(page_list);
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_migrate - migrate a charge to another page
|
|
* @oldpage: currently charged page
|
|
* @newpage: page to transfer the charge to
|
|
* @lrucare: both pages might be on the LRU already
|
|
*
|
|
* Migrate the charge from @oldpage to @newpage.
|
|
*
|
|
* Both pages must be locked, @newpage->mapping must be set up.
|
|
*/
|
|
void mem_cgroup_migrate(struct page *oldpage, struct page *newpage,
|
|
bool lrucare)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
int isolated;
|
|
|
|
VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage);
|
|
VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
|
|
VM_BUG_ON_PAGE(!lrucare && PageLRU(oldpage), oldpage);
|
|
VM_BUG_ON_PAGE(!lrucare && PageLRU(newpage), newpage);
|
|
VM_BUG_ON_PAGE(PageAnon(oldpage) != PageAnon(newpage), newpage);
|
|
VM_BUG_ON_PAGE(PageTransHuge(oldpage) != PageTransHuge(newpage),
|
|
newpage);
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
/* Page cache replacement: new page already charged? */
|
|
if (newpage->mem_cgroup)
|
|
return;
|
|
|
|
/*
|
|
* Swapcache readahead pages can get migrated before being
|
|
* charged, and migration from compaction can happen to an
|
|
* uncharged page when the PFN walker finds a page that
|
|
* reclaim just put back on the LRU but has not released yet.
|
|
*/
|
|
memcg = oldpage->mem_cgroup;
|
|
if (!memcg)
|
|
return;
|
|
|
|
if (lrucare)
|
|
lock_page_lru(oldpage, &isolated);
|
|
|
|
oldpage->mem_cgroup = NULL;
|
|
|
|
if (lrucare)
|
|
unlock_page_lru(oldpage, isolated);
|
|
|
|
commit_charge(newpage, memcg, lrucare);
|
|
}
|
|
|
|
/*
|
|
* subsys_initcall() for memory controller.
|
|
*
|
|
* Some parts like hotcpu_notifier() have to be initialized from this context
|
|
* because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
|
|
* everything that doesn't depend on a specific mem_cgroup structure should
|
|
* be initialized from here.
|
|
*/
|
|
static int __init mem_cgroup_init(void)
|
|
{
|
|
hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
|
|
enable_swap_cgroup();
|
|
mem_cgroup_soft_limit_tree_init();
|
|
memcg_stock_init();
|
|
return 0;
|
|
}
|
|
subsys_initcall(mem_cgroup_init);
|