From f7a449f779608efe1941a0e0c4bd7b5f57000be7 Mon Sep 17 00:00:00 2001 From: Roman Gushchin Date: Mon, 13 Feb 2023 11:29:22 -0800 Subject: [PATCH] mm: memcontrol: rename memcg_kmem_enabled() Currently there are two kmem-related helper functions with a confusing semantics: memcg_kmem_enabled() and mem_cgroup_kmem_disabled(). The problem is that an obvious expectation memcg_kmem_enabled() == !mem_cgroup_kmem_disabled(), can be false. mem_cgroup_kmem_disabled() is similar to mem_cgroup_disabled(): it returns true only if CONFIG_MEMCG_KMEM is not set or the kmem accounting is disabled using a boot time kernel option "cgroup.memory=nokmem". It never changes the value dynamically. memcg_kmem_enabled() is different: it always returns false until the first non-root memory cgroup will get online (assuming the kernel memory accounting is enabled). It's goal is to improve the performance on systems without the cgroupfs mounted/memory controller enabled or on the systems with only the root memory cgroup. To make things more obvious and avoid potential bugs, let's rename memcg_kmem_enabled() to memcg_kmem_online(). Link: https://lkml.kernel.org/r/20230213192922.1146370-1-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin Acked-by: Muchun Song Acked-by: Michal Hocko Cc: Johannes Weiner Cc: Shakeel Butt Cc: Dennis Zhou Signed-off-by: Andrew Morton --- include/linux/memcontrol.h | 14 +++++++------- mm/memcontrol.c | 8 ++++---- mm/page_alloc.c | 8 ++++---- mm/percpu.c | 2 +- mm/slab.h | 10 +++++----- mm/vmscan.c | 2 +- 6 files changed, 22 insertions(+), 22 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 3547869..5567319 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1776,24 +1776,24 @@ struct obj_cgroup *get_obj_cgroup_from_page(struct page *page); int obj_cgroup_charge(struct obj_cgroup *objcg, gfp_t gfp, size_t size); void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size); -extern struct static_key_false memcg_kmem_enabled_key; +extern struct static_key_false memcg_kmem_online_key; -static inline bool memcg_kmem_enabled(void) +static inline bool memcg_kmem_online(void) { - return static_branch_likely(&memcg_kmem_enabled_key); + return static_branch_likely(&memcg_kmem_online_key); } static inline int memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order) { - if (memcg_kmem_enabled()) + if (memcg_kmem_online()) return __memcg_kmem_charge_page(page, gfp, order); return 0; } static inline void memcg_kmem_uncharge_page(struct page *page, int order) { - if (memcg_kmem_enabled()) + if (memcg_kmem_online()) __memcg_kmem_uncharge_page(page, order); } @@ -1814,7 +1814,7 @@ static inline void count_objcg_event(struct obj_cgroup *objcg, { struct mem_cgroup *memcg; - if (!memcg_kmem_enabled()) + if (!memcg_kmem_online()) return; rcu_read_lock(); @@ -1854,7 +1854,7 @@ static inline struct obj_cgroup *get_obj_cgroup_from_page(struct page *page) return NULL; } -static inline bool memcg_kmem_enabled(void) +static inline bool memcg_kmem_online(void) { return false; } diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 1733545..3e3cdb9 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -345,8 +345,8 @@ static void memcg_reparent_objcgs(struct mem_cgroup *memcg, * conditional to this static branch, we'll have to allow modules that does * kmem_cache_alloc and the such to see this symbol as well */ -DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key); -EXPORT_SYMBOL(memcg_kmem_enabled_key); +DEFINE_STATIC_KEY_FALSE(memcg_kmem_online_key); +EXPORT_SYMBOL(memcg_kmem_online_key); #endif /** @@ -3034,7 +3034,7 @@ struct obj_cgroup *get_obj_cgroup_from_page(struct page *page) { struct obj_cgroup *objcg; - if (!memcg_kmem_enabled()) + if (!memcg_kmem_online()) return NULL; if (PageMemcgKmem(page)) { @@ -3746,7 +3746,7 @@ static int memcg_online_kmem(struct mem_cgroup *memcg) objcg->memcg = memcg; rcu_assign_pointer(memcg->objcg, objcg); - static_branch_enable(&memcg_kmem_enabled_key); + static_branch_enable(&memcg_kmem_online_key); memcg->kmemcg_id = memcg->id.id; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 4b6bcec..4c9ab8b 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1410,7 +1410,7 @@ static __always_inline bool free_pages_prepare(struct page *page, * Do not let hwpoison pages hit pcplists/buddy * Untie memcg state and reset page's owner */ - if (memcg_kmem_enabled() && PageMemcgKmem(page)) + if (memcg_kmem_online() && PageMemcgKmem(page)) __memcg_kmem_uncharge_page(page, order); reset_page_owner(page, order); page_table_check_free(page, order); @@ -1441,7 +1441,7 @@ static __always_inline bool free_pages_prepare(struct page *page, } if (PageMappingFlags(page)) page->mapping = NULL; - if (memcg_kmem_enabled() && PageMemcgKmem(page)) + if (memcg_kmem_online() && PageMemcgKmem(page)) __memcg_kmem_uncharge_page(page, order); if (check_free && free_page_is_bad(page)) bad++; @@ -5432,7 +5432,7 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid, goto out; /* Bulk allocator does not support memcg accounting. */ - if (memcg_kmem_enabled() && (gfp & __GFP_ACCOUNT)) + if (memcg_kmem_online() && (gfp & __GFP_ACCOUNT)) goto failed; /* Use the single page allocator for one page. */ @@ -5604,7 +5604,7 @@ struct page *__alloc_pages(gfp_t gfp, unsigned int order, int preferred_nid, page = __alloc_pages_slowpath(alloc_gfp, order, &ac); out: - if (memcg_kmem_enabled() && (gfp & __GFP_ACCOUNT) && page && + if (memcg_kmem_online() && (gfp & __GFP_ACCOUNT) && page && unlikely(__memcg_kmem_charge_page(page, gfp, order) != 0)) { __free_pages(page, order); page = NULL; diff --git a/mm/percpu.c b/mm/percpu.c index acd78da..28e07ed 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -1625,7 +1625,7 @@ static bool pcpu_memcg_pre_alloc_hook(size_t size, gfp_t gfp, { struct obj_cgroup *objcg; - if (!memcg_kmem_enabled() || !(gfp & __GFP_ACCOUNT)) + if (!memcg_kmem_online() || !(gfp & __GFP_ACCOUNT)) return true; objcg = get_obj_cgroup_from_current(); diff --git a/mm/slab.h b/mm/slab.h index 63fb4c0..43966aa 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -494,7 +494,7 @@ static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s, { struct obj_cgroup *objcg; - if (!memcg_kmem_enabled()) + if (!memcg_kmem_online()) return true; if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT)) @@ -535,7 +535,7 @@ static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, unsigned long off; size_t i; - if (!memcg_kmem_enabled() || !objcg) + if (!memcg_kmem_online() || !objcg) return; for (i = 0; i < size; i++) { @@ -567,7 +567,7 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab, struct obj_cgroup **objcgs; int i; - if (!memcg_kmem_enabled()) + if (!memcg_kmem_online()) return; objcgs = slab_objcgs(slab); @@ -649,7 +649,7 @@ static inline struct kmem_cache *virt_to_cache(const void *obj) static __always_inline void account_slab(struct slab *slab, int order, struct kmem_cache *s, gfp_t gfp) { - if (memcg_kmem_enabled() && (s->flags & SLAB_ACCOUNT)) + if (memcg_kmem_online() && (s->flags & SLAB_ACCOUNT)) memcg_alloc_slab_cgroups(slab, s, gfp, true); mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s), @@ -659,7 +659,7 @@ static __always_inline void account_slab(struct slab *slab, int order, static __always_inline void unaccount_slab(struct slab *slab, int order, struct kmem_cache *s) { - if (memcg_kmem_enabled()) + if (memcg_kmem_online()) memcg_free_slab_cgroups(slab); mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s), diff --git a/mm/vmscan.c b/mm/vmscan.c index 34535bb..098c791 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -915,7 +915,7 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid, } /* Call non-slab shrinkers even though kmem is disabled */ - if (!memcg_kmem_enabled() && + if (!memcg_kmem_online() && !(shrinker->flags & SHRINKER_NONSLAB)) continue; -- 2.7.4