From 2cb378c862777d050c20db903b119a029845fdcb Mon Sep 17 00:00:00 2001 From: Paul Menage Date: Wed, 7 Jan 2009 18:08:37 -0800 Subject: [PATCH] cgroups: use hierarchy_mutex in memory controller Update the memory controller to use its hierarchy_mutex rather than calling cgroup_lock() to protected against cgroup_mkdir()/cgroup_rmdir() from occurring in its hierarchy. Signed-off-by: Paul Menage Tested-by: KAMEZAWA Hiroyuki Cc: Li Zefan Cc: Balbir Singh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 93a792871804..e2996b80601f 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -154,7 +154,7 @@ struct mem_cgroup { /* * While reclaiming in a hiearchy, we cache the last child we - * reclaimed from. Protected by cgroup_lock() + * reclaimed from. Protected by hierarchy_mutex */ struct mem_cgroup *last_scanned_child; /* @@ -615,7 +615,7 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, /* * This routine finds the DFS walk successor. This routine should be - * called with cgroup_mutex held + * called with hierarchy_mutex held */ static struct mem_cgroup * mem_cgroup_get_next_node(struct mem_cgroup *curr, struct mem_cgroup *root_mem) @@ -685,7 +685,7 @@ mem_cgroup_get_first_node(struct mem_cgroup *root_mem) /* * Scan all children under the mem_cgroup mem */ - cgroup_lock(); + mutex_lock(&mem_cgroup_subsys.hierarchy_mutex); if (list_empty(&root_mem->css.cgroup->children)) { ret = root_mem; goto done; @@ -706,7 +706,7 @@ mem_cgroup_get_first_node(struct mem_cgroup *root_mem) done: root_mem->last_scanned_child = ret; - cgroup_unlock(); + mutex_unlock(&mem_cgroup_subsys.hierarchy_mutex); return ret; } @@ -770,18 +770,16 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, while (next_mem != root_mem) { if (mem_cgroup_is_obsolete(next_mem)) { mem_cgroup_put(next_mem); - cgroup_lock(); next_mem = mem_cgroup_get_first_node(root_mem); - cgroup_unlock(); continue; } ret = try_to_free_mem_cgroup_pages(next_mem, gfp_mask, noswap, get_swappiness(next_mem)); if (mem_cgroup_check_under_limit(root_mem)) return 0; - cgroup_lock(); + mutex_lock(&mem_cgroup_subsys.hierarchy_mutex); next_mem = mem_cgroup_get_next_node(next_mem, root_mem); - cgroup_unlock(); + mutex_unlock(&mem_cgroup_subsys.hierarchy_mutex); } return ret; } -- 2.20.1