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author | Li Zefan <lizf@cn.fujitsu.com> | 2009-02-11 13:04:36 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-02-11 14:25:36 -0800 |
commit | cfebe563bd0a3ff97e1bc167123120d59c7a84db (patch) | |
tree | 6178bf45bcccaf3d43d87cfe0eef059d849c7140 | |
parent | 01c4a4283137d24c9cc3785f1f312e895a18f273 (diff) | |
download | kernel_goldelico_gta04-cfebe563bd0a3ff97e1bc167123120d59c7a84db.zip kernel_goldelico_gta04-cfebe563bd0a3ff97e1bc167123120d59c7a84db.tar.gz kernel_goldelico_gta04-cfebe563bd0a3ff97e1bc167123120d59c7a84db.tar.bz2 |
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>
-rw-r--r-- | include/linux/cgroup.h | 1 | ||||
-rw-r--r-- | kernel/cgroup.c | 3 |
2 files changed, 3 insertions, 1 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index e4e8e11..499900d 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -378,6 +378,7 @@ struct cgroup_subsys { * - initiating hotplug events */ struct mutex hierarchy_mutex; + struct lock_class_key subsys_key; /* * Link to parent, and list entry in parent's children. diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 5a54ff4..e14db9c 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2351,7 +2351,7 @@ static void cgroup_lock_hierarchy(struct cgroupfs_root *root) 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); + mutex_lock(&ss->hierarchy_mutex); } } @@ -2637,6 +2637,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss) BUG_ON(!list_empty(&init_task.tasks)); mutex_init(&ss->hierarchy_mutex); + lockdep_set_class(&ss->hierarchy_mutex, &ss->subsys_key); ss->active = 1; } |