The patch titled Subject: memcg: only check memcg_kmem_skip_account in __memcg_kmem_get_cache has been removed from the -mm tree. Its filename was memcg-only-check-memcg_kmem_skip_account-in-__memcg_kmem_get_cache.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> Subject: memcg: only check memcg_kmem_skip_account in __memcg_kmem_get_cache __memcg_kmem_get_cache can recurse if it calls kmalloc (which it does if the cgroup's kmem cache doesn't exist), because kmalloc may call __memcg_kmem_get_cache internally again. To avoid the recursion, we use the task_struct->memcg_kmem_skip_account flag. However, there's no need checking the flag in memcg_kmem_newpage_charge, because there's no way how this function could result in recursion, if called from memcg_kmem_get_cache. So let's remove the redundant code. Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 28 ---------------------------- 1 file changed, 28 deletions(-) diff -puN mm/memcontrol.c~memcg-only-check-memcg_kmem_skip_account-in-__memcg_kmem_get_cache mm/memcontrol.c --- a/mm/memcontrol.c~memcg-only-check-memcg_kmem_skip_account-in-__memcg_kmem_get_cache +++ a/mm/memcontrol.c @@ -2905,34 +2905,6 @@ __memcg_kmem_newpage_charge(gfp_t gfp, s *_memcg = NULL; - /* - * Disabling accounting is only relevant for some specific memcg - * internal allocations. Therefore we would initially not have such - * check here, since direct calls to the page allocator that are - * accounted to kmemcg (alloc_kmem_pages and friends) only happen - * outside memcg core. We are mostly concerned with cache allocations, - * and by having this test at memcg_kmem_get_cache, we are already able - * to relay the allocation to the root cache and bypass the memcg cache - * altogether. - * - * There is one exception, though: the SLUB allocator does not create - * large order caches, but rather service large kmallocs directly from - * the page allocator. Therefore, the following sequence when backed by - * the SLUB allocator: - * - * memcg_stop_kmem_account(); - * kmalloc(<large_number>) - * memcg_resume_kmem_account(); - * - * would effectively ignore the fact that we should skip accounting, - * since it will drive us directly to this function without passing - * through the cache selector memcg_kmem_get_cache. Such large - * allocations are extremely rare but can happen, for instance, for the - * cache arrays. We bring this test here. - */ - if (current->memcg_kmem_skip_account) - return true; - memcg = get_mem_cgroup_from_mm(current->mm); if (!memcg_kmem_is_active(memcg)) { _ Patches currently in -mm which might be from vdavydov@xxxxxxxxxxxxx are origin.patch linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html