Commit 01c4b28c authored by Suren Baghdasaryan's avatar Suren Baghdasaryan Committed by Linus Torvalds
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mm, memcg: inline swap-related functions to improve disabled memcg config 

Inline mem_cgroup_try_charge_swap, mem_cgroup_uncharge_swap and
cgroup_throttle_swaprate functions to perform mem_cgroup_disabled static
key check inline before calling the main body of the function.  This
minimizes the memcg overhead in the pagefault and exit_mmap paths when
memcgs are disabled using cgroup_disable=memory command-line option.  This
change results in ~1% overhead reduction when running PFT test [1]
comparing {CONFIG_MEMCG=n} against {CONFIG_MEMCG=y, cgroup_disable=memory}
configuration on an 8-core ARM64 Android device.

[1] https://lkml.org/lkml/2006/8/29/294 also used in mmtests suite

Link: https://lkml.kernel.org/r/20210713010934.299876-3-surenb@google.com


Signed-off-by: default avatarSuren Baghdasaryan <surenb@google.com>
Reviewed-by: default avatarShakeel Butt <shakeelb@google.com>
Reviewed-by: default avatarMuchun Song <songmuchun@bytedance.com>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2c8d8f97

include/linux/swap.h

+23 −3
Original line number Diff line number Diff line
@@ -721,7 +721,13 @@ static inline int mem_cgroup_swappiness(struct mem_cgroup *mem) 
#endif



#if defined(CONFIG_SWAP) && defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)

extern void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask);

extern void __cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask);

static inline  void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)

{

	if (mem_cgroup_disabled())

		return;

	__cgroup_throttle_swaprate(page, gfp_mask);

}

#else

static inline void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)

{
@@ -730,8 +736,22 @@ static inline void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask) 


#ifdef CONFIG_MEMCG_SWAP

extern void mem_cgroup_swapout(struct page *page, swp_entry_t entry);

extern int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry);

extern void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages);

extern int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry);

static inline int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)

{

	if (mem_cgroup_disabled())

		return 0;

	return __mem_cgroup_try_charge_swap(page, entry);

}



extern void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages);

static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages)

{

	if (mem_cgroup_disabled())

		return;

	__mem_cgroup_uncharge_swap(entry, nr_pages);

}



extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg);

extern bool mem_cgroup_swap_full(struct page *page);

#else

mm/memcontrol.c

+4 −10
Original line number Diff line number Diff line
@@ -7226,7 +7226,7 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry) 
}



/**

 * mem_cgroup_try_charge_swap - try charging swap space for a page

 * __mem_cgroup_try_charge_swap - try charging swap space for a page

 * @page: page being added to swap

 * @entry: swap entry to charge

 *
@@ -7234,16 +7234,13 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry) 
 *

 * Returns 0 on success, -ENOMEM on failure.

 */

int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)

int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)

{

	unsigned int nr_pages = thp_nr_pages(page);

	struct page_counter *counter;

	struct mem_cgroup *memcg;

	unsigned short oldid;



	if (mem_cgroup_disabled())

		return 0;



	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))

		return 0;
@@ -7279,18 +7276,15 @@ int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) 
}



/**

 * mem_cgroup_uncharge_swap - uncharge swap space

 * __mem_cgroup_uncharge_swap - uncharge swap space

 * @entry: swap entry to uncharge

 * @nr_pages: the amount of swap space to uncharge

 */

void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages)

void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages)

{

	struct mem_cgroup *memcg;

	unsigned short id;



	if (mem_cgroup_disabled())

		return;



	id = swap_cgroup_record(entry, 0, nr_pages);

	rcu_read_lock();

	memcg = mem_cgroup_from_id(id);

mm/swapfile.c

+1 −4
Original line number Diff line number Diff line
@@ -3779,14 +3779,11 @@ static void free_swap_count_continuations(struct swap_info_struct *si) 
}



#if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)

void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)

void __cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)

{

	struct swap_info_struct *si, *next;

	int nid = page_to_nid(page);



	if (mem_cgroup_disabled())

		return;



	if (!(gfp_mask & __GFP_IO))

		return;