diff options
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/memcontrol.h | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index e98a74c..afa2ad4 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -21,6 +21,7 @@ #define _LINUX_MEMCONTROL_H #include <linux/cgroup.h> #include <linux/vm_event_item.h> +#include <linux/hardirq.h> struct mem_cgroup; struct page_cgroup; @@ -414,5 +415,114 @@ static inline void sock_release_memcg(struct sock *sk) { } #endif /* CONFIG_INET && CONFIG_MEMCG_KMEM */ + +#ifdef CONFIG_MEMCG_KMEM +static inline bool memcg_kmem_enabled(void) +{ + return true; +} + +/* + * 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); + +/** + * 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); +} + +#else +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) +{ +} +#endif /* CONFIG_MEMCG_KMEM */ #endif /* _LINUX_MEMCONTROL_H */ |