diff options
Diffstat (limited to 'include/linux/memcontrol.h')
| -rw-r--r-- | include/linux/memcontrol.h | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 45085e14e023..bd9b5d73bc2b 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -449,6 +449,10 @@ 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); + /** * memcg_kmem_newpage_charge: verify if a new kmem allocation is allowed. * @gfp: the gfp allocation flags. @@ -518,6 +522,37 @@ memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg, int order) __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 static inline bool memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **memcg, int order) @@ -553,6 +588,12 @@ 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; +} #endif /* CONFIG_MEMCG_KMEM */ #endif /* _LINUX_MEMCONTROL_H */ |