From 3ae8e2f18398056b285a688dc8b0cb0ff8b6e4bb Mon Sep 17 00:00:00 2001 From: Suren Baghdasaryan Date: Sat, 3 Jul 2021 16:11:33 -0700 Subject: [PATCH] BACKPORT: FROMLIST: mm, memcg: inline mem_cgroup_{charge/uncharge} to improve disabled memcg config Inline mem_cgroup_{charge/uncharge} and mem_cgroup_uncharge_list functions 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 ~0.4% 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 Signed-off-by: Suren Baghdasaryan Reviewed-by: Shakeel Butt Reviewed-by: Muchun Song Acked-by: Michal Hocko Acked-by: Johannes Weiner Conflicts: include/linux/memcontrol.h mm/memcontrol.c 1. Trivial merge conflicts in memcontrol.h 2. Did not need to rename __mem_cgroup_charge into memcg_charge as in the upstream version since in 5.10 __mem_cgroup_charge did not exist Link: https://lore.kernel.org/patchwork/patch/1458907/ Bug: 191223209 Signed-off-by: Suren Baghdasaryan Change-Id: I9aad72aeabec2fe01f7218d629ec545c47b5d2c3 --- include/linux/memcontrol.h | 27 ++++++++++++++++++++++++--- mm/memcontrol.c | 26 +++++++++----------------- 2 files changed, 33 insertions(+), 20 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index c691b1ac95f8..f99a651c9d21 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -441,10 +441,31 @@ static inline bool mem_cgroup_below_min(struct mem_cgroup *memcg) page_counter_read(&memcg->memory); } -int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask); +int __mem_cgroup_charge(struct page *page, struct mm_struct *mm, + gfp_t gfp_mask); +static inline int mem_cgroup_charge(struct page *page, struct mm_struct *mm, + gfp_t gfp_mask) +{ + if (mem_cgroup_disabled()) + return 0; + return __mem_cgroup_charge(page, mm, gfp_mask); +} -void mem_cgroup_uncharge(struct page *page); -void mem_cgroup_uncharge_list(struct list_head *page_list); +void __mem_cgroup_uncharge(struct page *page); +static inline void mem_cgroup_uncharge(struct page *page) +{ + if (mem_cgroup_disabled()) + return; + __mem_cgroup_uncharge(page); +} + +void __mem_cgroup_uncharge_list(struct list_head *page_list); +static inline void mem_cgroup_uncharge_list(struct list_head *page_list) +{ + if (mem_cgroup_disabled()) + return; + __mem_cgroup_uncharge_list(page_list); +} void mem_cgroup_migrate(struct page *oldpage, struct page *newpage); diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 77e8170b9d00..3e4adc987bee 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6761,7 +6761,7 @@ void mem_cgroup_calculate_protection(struct mem_cgroup *root, } /** - * mem_cgroup_charge - charge a newly allocated page to a cgroup + * __mem_cgroup_charge - charge a newly allocated page to a cgroup * @page: page to charge * @mm: mm context of the victim * @gfp_mask: reclaim mode @@ -6771,15 +6771,13 @@ void mem_cgroup_calculate_protection(struct mem_cgroup *root, * * Returns 0 on success. Otherwise, an error code is returned. */ -int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask) +int __mem_cgroup_charge(struct page *page, struct mm_struct *mm, + gfp_t gfp_mask) { unsigned int nr_pages = thp_nr_pages(page); struct mem_cgroup *memcg = NULL; int ret = 0; - if (mem_cgroup_disabled()) - goto out; - if (PageSwapCache(page)) { swp_entry_t ent = { .val = page_private(page), }; unsigned short id; @@ -6949,18 +6947,15 @@ static void uncharge_list(struct list_head *page_list) } /** - * mem_cgroup_uncharge - uncharge a page + * __mem_cgroup_uncharge - uncharge a page * @page: page to uncharge * - * Uncharge a page previously charged with mem_cgroup_charge(). + * Uncharge a page previously charged with __mem_cgroup_charge(). */ -void mem_cgroup_uncharge(struct page *page) +void __mem_cgroup_uncharge(struct page *page) { struct uncharge_gather ug; - if (mem_cgroup_disabled()) - return; - /* Don't touch page->lru of any random page, pre-check: */ if (!page->mem_cgroup) return; @@ -6971,17 +6966,14 @@ void mem_cgroup_uncharge(struct page *page) } /** - * mem_cgroup_uncharge_list - uncharge a list of page + * __mem_cgroup_uncharge_list - uncharge a list of page * @page_list: list of pages to uncharge * * Uncharge a list of pages previously charged with - * mem_cgroup_charge(). + * __mem_cgroup_charge(). */ -void mem_cgroup_uncharge_list(struct list_head *page_list) +void __mem_cgroup_uncharge_list(struct list_head *page_list) { - if (mem_cgroup_disabled()) - return; - if (!list_empty(page_list)) uncharge_list(page_list); }