From 69bb55d73640d7e6d64a75065dbfb06ade4b4352 Mon Sep 17 00:00:00 2001 From: Vladimir Davydov Date: Mon, 7 Apr 2014 15:39:31 -0700 Subject: slub: rework sysfs layout for memcg caches Currently, we try to arrange sysfs entries for memcg caches in the same manner as for global caches. Apart from turning /sys/kernel/slab into a mess when there are a lot of kmem-active memcgs created, it actually does not work properly - we won't create more than one link to a memcg cache in case its parent is merged with another cache. For instance, if A is a root cache merged with another root cache B, we will have the following sysfs setup: X A -> X B -> X where X is some unique id (see create_unique_id()). Now if memcgs M and N start to allocate from cache A (or B, which is the same), we will get: X X:M X:N A -> X B -> X A:M -> X:M A:N -> X:N Since B is an alias for A, we won't get entries B:M and B:N, which is confusing. It is more logical to have entries for memcg caches under the corresponding root cache's sysfs directory. This would allow us to keep sysfs layout clean, and avoid such inconsistencies like one described above. This patch does the trick. It creates a "cgroup" kset in each root cache kobject to keep its children caches there. Signed-off-by: Vladimir Davydov Cc: Michal Hocko Cc: Johannes Weiner Cc: David Rientjes Cc: Pekka Enberg Cc: Glauber Costa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: W4TCH0UT --- include/linux/slub_def.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h index 027276fa8..ab1d4d123 100644 --- a/include/linux/slub_def.h +++ b/include/linux/slub_def.h @@ -93,6 +93,9 @@ struct kmem_cache { #ifdef CONFIG_MEMCG_KMEM struct memcg_cache_params *memcg_params; int max_attr_size; /* for propagation, maximum size of a stored attr */ +#ifdef CONFIG_SYSFS + struct kset *memcg_kset; +#endif #endif #ifdef CONFIG_NUMA -- cgit v1.2.3