linux_dsm_epyc7002/include/linux/memcontrol.h
Johannes Weiner d7365e783e mm: memcontrol: fix missed end-writeback page accounting
Commit 0a31bc97c8 ("mm: memcontrol: rewrite uncharge API") changed
page migration to uncharge the old page right away.  The page is locked,
unmapped, truncated, and off the LRU, but it could race with writeback
ending, which then doesn't unaccount the page properly:

test_clear_page_writeback()              migration
                                           wait_on_page_writeback()
  TestClearPageWriteback()
                                           mem_cgroup_migrate()
                                             clear PCG_USED
  mem_cgroup_update_page_stat()
    if (PageCgroupUsed(pc))
      decrease memcg pages under writeback

  release pc->mem_cgroup->move_lock

The per-page statistics interface is heavily optimized to avoid a
function call and a lookup_page_cgroup() in the file unmap fast path,
which means it doesn't verify whether a page is still charged before
clearing PageWriteback() and it has to do it in the stat update later.

Rework it so that it looks up the page's memcg once at the beginning of
the transaction and then uses it throughout.  The charge will be
verified before clearing PageWriteback() and migration can't uncharge
the page as long as that is still set.  The RCU lock will protect the
memcg past uncharge.

As far as losing the optimization goes, the following test results are
from a microbenchmark that maps, faults, and unmaps a 4GB sparse file
three times in a nested fashion, so that there are two negative passes
that don't account but still go through the new transaction overhead.
There is no actual difference:

 old:     33.195102545 seconds time elapsed       ( +-  0.01% )
 new:     33.199231369 seconds time elapsed       ( +-  0.03% )

The time spent in page_remove_rmap()'s callees still adds up to the
same, but the time spent in the function itself seems reduced:

     # Children      Self  Command        Shared Object       Symbol
 old:     0.12%     0.11%  filemapstress  [kernel.kallsyms]   [k] page_remove_rmap
 new:     0.12%     0.08%  filemapstress  [kernel.kallsyms]   [k] page_remove_rmap

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: <stable@vger.kernel.org>	[3.17.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-29 16:33:15 -07:00

556 lines
14 KiB
C

/* memcontrol.h - Memory Controller
*
* Copyright IBM Corporation, 2007
* Author Balbir Singh <balbir@linux.vnet.ibm.com>
*
* Copyright 2007 OpenVZ SWsoft Inc
* Author: Pavel Emelianov <xemul@openvz.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef _LINUX_MEMCONTROL_H
#define _LINUX_MEMCONTROL_H
#include <linux/cgroup.h>
#include <linux/vm_event_item.h>
#include <linux/hardirq.h>
#include <linux/jump_label.h>
struct mem_cgroup;
struct page_cgroup;
struct page;
struct mm_struct;
struct kmem_cache;
/*
* The corresponding mem_cgroup_stat_names is defined in mm/memcontrol.c,
* These two lists should keep in accord with each other.
*/
enum mem_cgroup_stat_index {
/*
* For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
*/
MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */
MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */
MEM_CGROUP_STAT_RSS_HUGE, /* # of pages charged as anon huge */
MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */
MEM_CGROUP_STAT_WRITEBACK, /* # of pages under writeback */
MEM_CGROUP_STAT_SWAP, /* # of pages, swapped out */
MEM_CGROUP_STAT_NSTATS,
};
struct mem_cgroup_reclaim_cookie {
struct zone *zone;
int priority;
unsigned int generation;
};
#ifdef CONFIG_MEMCG
int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
gfp_t gfp_mask, struct mem_cgroup **memcgp);
void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,
bool lrucare);
void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg);
void mem_cgroup_uncharge(struct page *page);
void mem_cgroup_uncharge_list(struct list_head *page_list);
void mem_cgroup_migrate(struct page *oldpage, struct page *newpage,
bool lrucare);
struct lruvec *mem_cgroup_zone_lruvec(struct zone *, struct mem_cgroup *);
struct lruvec *mem_cgroup_page_lruvec(struct page *, struct zone *);
bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
struct mem_cgroup *memcg);
bool task_in_mem_cgroup(struct task_struct *task,
const struct mem_cgroup *memcg);
extern struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page);
extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
extern struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg);
extern struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css);
static inline
bool mm_match_cgroup(const struct mm_struct *mm, const struct mem_cgroup *memcg)
{
struct mem_cgroup *task_memcg;
bool match;
rcu_read_lock();
task_memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
match = __mem_cgroup_same_or_subtree(memcg, task_memcg);
rcu_read_unlock();
return match;
}
extern struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg);
struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *,
struct mem_cgroup *,
struct mem_cgroup_reclaim_cookie *);
void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *);
/*
* For memory reclaim.
*/
int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec);
int mem_cgroup_select_victim_node(struct mem_cgroup *memcg);
unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list);
void mem_cgroup_update_lru_size(struct lruvec *, enum lru_list, int);
extern void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
struct task_struct *p);
static inline void mem_cgroup_oom_enable(void)
{
WARN_ON(current->memcg_oom.may_oom);
current->memcg_oom.may_oom = 1;
}
static inline void mem_cgroup_oom_disable(void)
{
WARN_ON(!current->memcg_oom.may_oom);
current->memcg_oom.may_oom = 0;
}
static inline bool task_in_memcg_oom(struct task_struct *p)
{
return p->memcg_oom.memcg;
}
bool mem_cgroup_oom_synchronize(bool wait);
#ifdef CONFIG_MEMCG_SWAP
extern int do_swap_account;
#endif
static inline bool mem_cgroup_disabled(void)
{
if (memory_cgrp_subsys.disabled)
return true;
return false;
}
struct mem_cgroup *mem_cgroup_begin_page_stat(struct page *page, bool *locked,
unsigned long *flags);
void mem_cgroup_end_page_stat(struct mem_cgroup *memcg, bool locked,
unsigned long flags);
void mem_cgroup_update_page_stat(struct mem_cgroup *memcg,
enum mem_cgroup_stat_index idx, int val);
static inline void mem_cgroup_inc_page_stat(struct mem_cgroup *memcg,
enum mem_cgroup_stat_index idx)
{
mem_cgroup_update_page_stat(memcg, idx, 1);
}
static inline void mem_cgroup_dec_page_stat(struct mem_cgroup *memcg,
enum mem_cgroup_stat_index idx)
{
mem_cgroup_update_page_stat(memcg, idx, -1);
}
unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
gfp_t gfp_mask,
unsigned long *total_scanned);
void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx);
static inline void mem_cgroup_count_vm_event(struct mm_struct *mm,
enum vm_event_item idx)
{
if (mem_cgroup_disabled())
return;
__mem_cgroup_count_vm_event(mm, idx);
}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
void mem_cgroup_split_huge_fixup(struct page *head);
#endif
#ifdef CONFIG_DEBUG_VM
bool mem_cgroup_bad_page_check(struct page *page);
void mem_cgroup_print_bad_page(struct page *page);
#endif
#else /* CONFIG_MEMCG */
struct mem_cgroup;
static inline int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
gfp_t gfp_mask,
struct mem_cgroup **memcgp)
{
*memcgp = NULL;
return 0;
}
static inline void mem_cgroup_commit_charge(struct page *page,
struct mem_cgroup *memcg,
bool lrucare)
{
}
static inline void mem_cgroup_cancel_charge(struct page *page,
struct mem_cgroup *memcg)
{
}
static inline void mem_cgroup_uncharge(struct page *page)
{
}
static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
{
}
static inline void mem_cgroup_migrate(struct page *oldpage,
struct page *newpage,
bool lrucare)
{
}
static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
struct mem_cgroup *memcg)
{
return &zone->lruvec;
}
static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page,
struct zone *zone)
{
return &zone->lruvec;
}
static inline struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
{
return NULL;
}
static inline bool mm_match_cgroup(struct mm_struct *mm,
struct mem_cgroup *memcg)
{
return true;
}
static inline bool task_in_mem_cgroup(struct task_struct *task,
const struct mem_cgroup *memcg)
{
return true;
}
static inline struct cgroup_subsys_state
*mem_cgroup_css(struct mem_cgroup *memcg)
{
return NULL;
}
static inline struct mem_cgroup *
mem_cgroup_iter(struct mem_cgroup *root,
struct mem_cgroup *prev,
struct mem_cgroup_reclaim_cookie *reclaim)
{
return NULL;
}
static inline void mem_cgroup_iter_break(struct mem_cgroup *root,
struct mem_cgroup *prev)
{
}
static inline bool mem_cgroup_disabled(void)
{
return true;
}
static inline int
mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
{
return 1;
}
static inline unsigned long
mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
{
return 0;
}
static inline void
mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
int increment)
{
}
static inline void
mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
{
}
static inline struct mem_cgroup *mem_cgroup_begin_page_stat(struct page *page,
bool *locked, unsigned long *flags)
{
return NULL;
}
static inline void mem_cgroup_end_page_stat(struct mem_cgroup *memcg,
bool locked, unsigned long flags)
{
}
static inline void mem_cgroup_oom_enable(void)
{
}
static inline void mem_cgroup_oom_disable(void)
{
}
static inline bool task_in_memcg_oom(struct task_struct *p)
{
return false;
}
static inline bool mem_cgroup_oom_synchronize(bool wait)
{
return false;
}
static inline void mem_cgroup_inc_page_stat(struct mem_cgroup *memcg,
enum mem_cgroup_stat_index idx)
{
}
static inline void mem_cgroup_dec_page_stat(struct mem_cgroup *memcg,
enum mem_cgroup_stat_index idx)
{
}
static inline
unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
gfp_t gfp_mask,
unsigned long *total_scanned)
{
return 0;
}
static inline void mem_cgroup_split_huge_fixup(struct page *head)
{
}
static inline
void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
{
}
#endif /* CONFIG_MEMCG */
#if !defined(CONFIG_MEMCG) || !defined(CONFIG_DEBUG_VM)
static inline bool
mem_cgroup_bad_page_check(struct page *page)
{
return false;
}
static inline void
mem_cgroup_print_bad_page(struct page *page)
{
}
#endif
enum {
UNDER_LIMIT,
SOFT_LIMIT,
OVER_LIMIT,
};
struct sock;
#if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
void sock_update_memcg(struct sock *sk);
void sock_release_memcg(struct sock *sk);
#else
static inline void sock_update_memcg(struct sock *sk)
{
}
static inline void sock_release_memcg(struct sock *sk)
{
}
#endif /* CONFIG_INET && CONFIG_MEMCG_KMEM */
#ifdef CONFIG_MEMCG_KMEM
extern struct static_key memcg_kmem_enabled_key;
extern int memcg_limited_groups_array_size;
/*
* Helper macro to loop through all memcg-specific caches. Callers must still
* check if the cache is valid (it is either valid or NULL).
* the slab_mutex must be held when looping through those caches
*/
#define for_each_memcg_cache_index(_idx) \
for ((_idx) = 0; (_idx) < memcg_limited_groups_array_size; (_idx)++)
static inline bool memcg_kmem_enabled(void)
{
return static_key_false(&memcg_kmem_enabled_key);
}
/*
* In general, we'll do everything in our power to not incur in any overhead
* for non-memcg users for the kmem functions. Not even a function call, if we
* can avoid it.
*
* Therefore, we'll inline all those functions so that in the best case, we'll
* see that kmemcg is off for everybody and proceed quickly. If it is on,
* we'll still do most of the flag checking inline. We check a lot of
* conditions, but because they are pretty simple, they are expected to be
* fast.
*/
bool __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **memcg,
int order);
void __memcg_kmem_commit_charge(struct page *page,
struct mem_cgroup *memcg, int order);
void __memcg_kmem_uncharge_pages(struct page *page, int order);
int memcg_cache_id(struct mem_cgroup *memcg);
void memcg_update_array_size(int num_groups);
struct kmem_cache *
__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp);
int __memcg_charge_slab(struct kmem_cache *cachep, gfp_t gfp, int order);
void __memcg_uncharge_slab(struct kmem_cache *cachep, int order);
int __memcg_cleanup_cache_params(struct kmem_cache *s);
/**
* memcg_kmem_newpage_charge: verify if a new kmem allocation is allowed.
* @gfp: the gfp allocation flags.
* @memcg: a pointer to the memcg this was charged against.
* @order: allocation order.
*
* returns true if the memcg where the current task belongs can hold this
* allocation.
*
* We return true automatically if this allocation is not to be accounted to
* any memcg.
*/
static inline bool
memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **memcg, int order)
{
if (!memcg_kmem_enabled())
return true;
/*
* __GFP_NOFAIL allocations will move on even if charging is not
* possible. Therefore we don't even try, and have this allocation
* unaccounted. We could in theory charge it with
* res_counter_charge_nofail, but we hope those allocations are rare,
* and won't be worth the trouble.
*/
if (gfp & __GFP_NOFAIL)
return true;
if (in_interrupt() || (!current->mm) || (current->flags & PF_KTHREAD))
return true;
/* If the test is dying, just let it go. */
if (unlikely(fatal_signal_pending(current)))
return true;
return __memcg_kmem_newpage_charge(gfp, memcg, order);
}
/**
* memcg_kmem_uncharge_pages: uncharge pages from memcg
* @page: pointer to struct page being freed
* @order: allocation order.
*
* there is no need to specify memcg here, since it is embedded in page_cgroup
*/
static inline void
memcg_kmem_uncharge_pages(struct page *page, int order)
{
if (memcg_kmem_enabled())
__memcg_kmem_uncharge_pages(page, order);
}
/**
* memcg_kmem_commit_charge: embeds correct memcg in a page
* @page: pointer to struct page recently allocated
* @memcg: the memcg structure we charged against
* @order: allocation order.
*
* Needs to be called after memcg_kmem_newpage_charge, regardless of success or
* failure of the allocation. if @page is NULL, this function will revert the
* charges. Otherwise, it will commit the memcg given by @memcg to the
* corresponding page_cgroup.
*/
static inline void
memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg, int order)
{
if (memcg_kmem_enabled() && memcg)
__memcg_kmem_commit_charge(page, memcg, order);
}
/**
* memcg_kmem_get_cache: selects the correct per-memcg cache for allocation
* @cachep: the original global kmem cache
* @gfp: allocation flags.
*
* All memory allocated from a per-memcg cache is charged to the owner memcg.
*/
static __always_inline struct kmem_cache *
memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
{
if (!memcg_kmem_enabled())
return cachep;
if (gfp & __GFP_NOFAIL)
return cachep;
if (in_interrupt() || (!current->mm) || (current->flags & PF_KTHREAD))
return cachep;
if (unlikely(fatal_signal_pending(current)))
return cachep;
return __memcg_kmem_get_cache(cachep, gfp);
}
#else
#define for_each_memcg_cache_index(_idx) \
for (; NULL; )
static inline bool memcg_kmem_enabled(void)
{
return false;
}
static inline bool
memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **memcg, int order)
{
return true;
}
static inline void memcg_kmem_uncharge_pages(struct page *page, int order)
{
}
static inline void
memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg, int order)
{
}
static inline int memcg_cache_id(struct mem_cgroup *memcg)
{
return -1;
}
static inline struct kmem_cache *
memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
{
return cachep;
}
#endif /* CONFIG_MEMCG_KMEM */
#endif /* _LINUX_MEMCONTROL_H */