diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 64ede5f150dc..0277fbab7c93 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -198,7 +198,10 @@ struct page { atomic_t _refcount; #ifdef CONFIG_MEMCG - struct mem_cgroup *mem_cgroup; + union { + struct mem_cgroup *mem_cgroup; + struct obj_cgroup **obj_cgroups; + }; #endif /* diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h index abc7de77b988..ccda7b9669a5 100644 --- a/include/linux/slab_def.h +++ b/include/linux/slab_def.h @@ -114,4 +114,10 @@ static inline unsigned int obj_to_index(const struct kmem_cache *cache, return reciprocal_divide(offset, cache->reciprocal_buffer_size); } +static inline int objs_per_slab_page(const struct kmem_cache *cache, + const struct page *page) +{ + return cache->num; +} + #endif /* _LINUX_SLAB_DEF_H */ diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h index 30e91c83d401..f87302dcfe8c 100644 --- a/include/linux/slub_def.h +++ b/include/linux/slub_def.h @@ -198,4 +198,9 @@ static inline unsigned int obj_to_index(const struct kmem_cache *cache, return __obj_to_index(cache, page_address(page), obj); } +static inline int objs_per_slab_page(const struct kmem_cache *cache, + const struct page *page) +{ + return page->objects; +} #endif /* _LINUX_SLUB_DEF_H */ diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 1cc784556e05..e6cd4c0d44d1 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -569,10 +569,21 @@ ino_t page_cgroup_ino(struct page *page) unsigned long ino = 0; rcu_read_lock(); - if (PageSlab(page) && !PageTail(page)) + if (PageSlab(page) && !PageTail(page)) { memcg = memcg_from_slab_page(page); - else - memcg = READ_ONCE(page->mem_cgroup); + } else { + memcg = page->mem_cgroup; + + /* + * The lowest bit set means that memcg isn't a valid + * memcg pointer, but a obj_cgroups pointer. + * In this case the page is shared and doesn't belong + * to any specific memory cgroup. + */ + if ((unsigned long) memcg & 0x1UL) + memcg = NULL; + } + while (memcg && !(memcg->css.flags & CSS_ONLINE)) memcg = parent_mem_cgroup(memcg); if (memcg) diff --git a/mm/slab.h b/mm/slab.h index 161ca34acb01..9f78e3167f19 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -109,6 +109,7 @@ struct memcg_cache_params { #include #include #include +#include /* * State of the slab allocator. @@ -348,6 +349,18 @@ static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s) return s->memcg_params.root_cache; } +static inline struct obj_cgroup **page_obj_cgroups(struct page *page) +{ + /* + * page->mem_cgroup and page->obj_cgroups are sharing the same + * space. To distinguish between them in case we don't know for sure + * that the page is a slab page (e.g. page_cgroup_ino()), let's + * always set the lowest bit of obj_cgroups. + */ + return (struct obj_cgroup **) + ((unsigned long)page->obj_cgroups & ~0x1UL); +} + /* * Expects a pointer to a slab page. Please note, that PageSlab() check * isn't sufficient, as it returns true also for tail compound slab pages, @@ -435,6 +448,28 @@ static __always_inline void memcg_uncharge_slab(struct page *page, int order, percpu_ref_put_many(&s->memcg_params.refcnt, nr_pages); } +static inline int memcg_alloc_page_obj_cgroups(struct page *page, + struct kmem_cache *s, gfp_t gfp) +{ + unsigned int objects = objs_per_slab_page(s, page); + void *vec; + + vec = kcalloc_node(objects, sizeof(struct obj_cgroup *), gfp, + page_to_nid(page)); + if (!vec) + return -ENOMEM; + + kmemleak_not_leak(vec); + page->obj_cgroups = (struct obj_cgroup **) ((unsigned long)vec | 0x1UL); + return 0; +} + +static inline void memcg_free_page_obj_cgroups(struct page *page) +{ + kfree(page_obj_cgroups(page)); + page->obj_cgroups = NULL; +} + extern void slab_init_memcg_params(struct kmem_cache *); extern void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg); @@ -484,6 +519,16 @@ static inline void memcg_uncharge_slab(struct page *page, int order, { } +static inline int memcg_alloc_page_obj_cgroups(struct page *page, + struct kmem_cache *s, gfp_t gfp) +{ + return 0; +} + +static inline void memcg_free_page_obj_cgroups(struct page *page) +{ +} + static inline void slab_init_memcg_params(struct kmem_cache *s) { } @@ -510,12 +555,18 @@ static __always_inline int charge_slab_page(struct page *page, gfp_t gfp, int order, struct kmem_cache *s) { + int ret; + if (is_root_cache(s)) { mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), PAGE_SIZE << order); return 0; } + ret = memcg_alloc_page_obj_cgroups(page, s, gfp); + if (ret) + return ret; + return memcg_charge_slab(page, gfp, order, s); } @@ -528,6 +579,7 @@ static __always_inline void uncharge_slab_page(struct page *page, int order, return; } + memcg_free_page_obj_cgroups(page); memcg_uncharge_slab(page, order, s); }