Subject: [merged] memcg-kmem-fix-reference-count-handling-on-the-error-path.patch removed from -mm tree To: mhocko@xxxxxxx,glommer@xxxxxxxxxx,hannes@xxxxxxxxxxx,hughd@xxxxxxxxxx,kamezawa.hiroyu@xxxxxxxxxxxxxx,lizefan@xxxxxxxxxx,stable@xxxxxxxxxxxxxxx,tj@xxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Tue, 09 Jul 2013 16:20:35 -0700 The patch titled Subject: memcg, kmem: fix reference count handling on the error path has been removed from the -mm tree. Its filename was memcg-kmem-fix-reference-count-handling-on-the-error-path.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Michal Hocko <mhocko@xxxxxxx> Subject: memcg, kmem: fix reference count handling on the error path mem_cgroup_css_online calls mem_cgroup_put if memcg_init_kmem fails. This is not correct because only memcg_propagate_kmem takes an additional reference while mem_cgroup_sockets_init is allowed to fail as well (although no current implementation fails) but it doesn't take any reference. This all suggests that it should be memcg_propagate_kmem that should clean up after itself so this patch moves mem_cgroup_put over there. Unfortunately this is not that easy (as pointed out by Li Zefan) because memcg_kmem_mark_dead marks the group dead (KMEM_ACCOUNTED_DEAD) if it is marked active (KMEM_ACCOUNTED_ACTIVE) which is the case even if memcg_propagate_kmem fails so the additional reference is dropped in that case in kmem_cgroup_destroy which means that the reference would be dropped two times. The easiest way then would be to simply remove mem_cgrroup_put from mem_cgroup_css_online and rely on kmem_cgroup_destroy doing the right thing. Signed-off-by: Michal Hocko <mhocko@xxxxxxx> Signed-off-by: Li Zefan <lizefan@xxxxxxxxxx> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Glauber Costa <glommer@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [3.8] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 8 -------- 1 file changed, 8 deletions(-) diff -puN mm/memcontrol.c~memcg-kmem-fix-reference-count-handling-on-the-error-path mm/memcontrol.c --- a/mm/memcontrol.c~memcg-kmem-fix-reference-count-handling-on-the-error-path +++ a/mm/memcontrol.c @@ -6345,14 +6345,6 @@ mem_cgroup_css_online(struct cgroup *con error = memcg_init_kmem(memcg, &mem_cgroup_subsys); mutex_unlock(&memcg_create_mutex); - if (error) { - /* - * We call put now because our (and parent's) refcnts - * are already in place. mem_cgroup_put() will internally - * call __mem_cgroup_free, so return directly - */ - mem_cgroup_put(memcg); - } return error; } _ Patches currently in -mm which might be from mhocko@xxxxxxx are origin.patch linux-next.patch include-linux-schedh-dont-use-task-pid-tgid-in-same_thread_group-has_group_leader_pid.patch inode-convert-inode-lru-list-to-generic-lru-list-code-inode-move-inode-to-a-different-list-inside-lock.patch list_lru-per-node-list-infrastructure-fix-broken-lru_retry-behaviour.patch list_lru-remove-special-case-function-list_lru_dispose_all.patch xfs-convert-dquot-cache-lru-to-list_lru-fix-dquot-isolation-hang.patch list_lru-dynamically-adjust-node-arrays-super-fix-for-destroy-lrus.patch drop_caches-add-some-documentation-and-info-messsge.patch staging-lustre-ldlm-convert-to-shrinkers-to-count-scan-api.patch staging-lustre-obdclass-convert-lu_object-shrinker-to-count-scan-api.patch staging-lustre-ptlrpc-convert-to-new-shrinker-api.patch staging-lustre-libcfs-cleanup-linux-memh.patch staging-lustre-replace-num_physpages-with-totalram_pages.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