This patch updates 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 --- mm/memcontrol.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) Index: hierarchy_lock-mmotm-2008-12-09/mm/memcontrol.c =================================================================== --- hierarchy_lock-mmotm-2008-12-09.orig/mm/memcontrol.c +++ hierarchy_lock-mmotm-2008-12-09/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; /* @@ -529,7 +529,7 @@ unsigned long mem_cgroup_isolate_pages(u /* * 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) @@ -598,7 +598,7 @@ mem_cgroup_get_first_node(struct mem_cgr /* * 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; @@ -619,7 +619,7 @@ mem_cgroup_get_first_node(struct mem_cgr done: root_mem->last_scanned_child = ret; - cgroup_unlock(); + mutex_unlock(&mem_cgroup_subsys.hierarchy_mutex); return ret; } @@ -683,18 +683,16 @@ static int mem_cgroup_hierarchical_recla while (next_mem != root_mem) { if (next_mem->obsolete) { 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; } -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/