diff options
Diffstat (limited to 'include/linux/memcontrol.h')
| -rw-r--r-- | include/linux/memcontrol.h | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index e98a74c0c9c0..0108a56f814e 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -21,11 +21,14 @@ #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; /* Stats that can be updated by kernel. */ enum mem_cgroup_page_stat_item { @@ -414,5 +417,211 @@ 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; i < 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); +int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s, + struct kmem_cache *root_cache); +void memcg_release_cache(struct kmem_cache *cachep); +void memcg_cache_list_add(struct mem_cgroup *memcg, struct kmem_cache *cachep); + +int memcg_update_cache_size(struct kmem_cache *s, int num_groups); +void memcg_update_array_size(int num_groups); + +struct kmem_cache * +__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp); + +void mem_cgroup_destroy_cache(struct kmem_cache *cachep); +void kmem_cache_destroy_memcg_children(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_KMEMCG) || (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. + * + * This function assumes that the task allocating, which determines the memcg + * in the page allocator, belongs to the same cgroup throughout the whole + * process. Misacounting can happen if the task calls memcg_kmem_get_cache() + * while belonging to a cgroup, and later on changes. This is considered + * acceptable, and should only happen upon task migration. + * + * Before the cache is created by the memcg core, there is also a possible + * imbalance: the task belongs to a memcg, but the cache being allocated from + * is the global cache, since the child cache is not yet guaranteed to be + * ready. This case is also fine, since in this case the GFP_KMEMCG will not be + * passed and the page allocator will not attempt any cgroup accounting. + */ +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 int +memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s, + struct kmem_cache *root_cache) +{ + return 0; +} + +static inline void memcg_release_cache(struct kmem_cache *cachep) +{ +} + +static inline void memcg_cache_list_add(struct mem_cgroup *memcg, + struct kmem_cache *s) +{ +} + +static inline struct kmem_cache * +memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp) +{ + return cachep; +} + +static inline void kmem_cache_destroy_memcg_children(struct kmem_cache *s) +{ +} +#endif /* CONFIG_MEMCG_KMEM */ #endif /* _LINUX_MEMCONTROL_H */ |