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authorLi Zefan <lizf@cn.fujitsu.com>2009-02-11 16:04:36 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2009-02-11 17:25:36 -0500
commitcfebe563bd0a3ff97e1bc167123120d59c7a84db (patch)
tree6178bf45bcccaf3d43d87cfe0eef059d849c7140 /kernel
parent01c4a4283137d24c9cc3785f1f312e895a18f273 (diff)
cgroups: fix lockdep subclasses overflow
I enabled all cgroup subsystems when compiling kernel, and then: # mount -t cgroup -o net_cls xxx /mnt # mkdir /mnt/0 This showed up immediately: BUG: MAX_LOCKDEP_SUBCLASSES too low! turning off the locking correctness validator. It's caused by the cgroup hierarchy lock: for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { struct cgroup_subsys *ss = subsys[i]; if (ss->root == root) mutex_lock_nested(&ss->hierarchy_mutex, i); } Now we have 9 cgroup subsystems, and the above 'i' for net_cls is 8, but MAX_LOCKDEP_SUBCLASSES is 8. This patch uses different lockdep keys for different subsystems. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 5a54ff42874e..e14db9c089b9 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2351,7 +2351,7 @@ static void cgroup_lock_hierarchy(struct cgroupfs_root *root)
2351 for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { 2351 for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
2352 struct cgroup_subsys *ss = subsys[i]; 2352 struct cgroup_subsys *ss = subsys[i];
2353 if (ss->root == root) 2353 if (ss->root == root)
2354 mutex_lock_nested(&ss->hierarchy_mutex, i); 2354 mutex_lock(&ss->hierarchy_mutex);
2355 } 2355 }
2356} 2356}
2357 2357
@@ -2637,6 +2637,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss)
2637 BUG_ON(!list_empty(&init_task.tasks)); 2637 BUG_ON(!list_empty(&init_task.tasks));
2638 2638
2639 mutex_init(&ss->hierarchy_mutex); 2639 mutex_init(&ss->hierarchy_mutex);
2640 lockdep_set_class(&ss->hierarchy_mutex, &ss->subsys_key);
2640 ss->active = 1; 2641 ss->active = 1;
2641} 2642}
2642 2643