oom: do not take callback_mutex
Since no task descriptor's 'cpuset' field is dereferenced in the execution of
the OOM killer anymore, it is no longer necessary to take callback_mutex.
[akpm@linux-foundation.org: restore cpuset_lock for other patches]
Cc: Andrea Arcangeli <andrea@suse.de>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index d9bba82..183a964 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -463,7 +463,6 @@
* NUMA) that may require different handling.
*/
constraint = constrained_alloc(zonelist, gfp_mask);
- cpuset_lock();
read_lock(&tasklist_lock);
switch (constraint) {
@@ -495,7 +494,6 @@
/* Found nothing?!?! Either we hang forever, or we panic. */
if (!p) {
read_unlock(&tasklist_lock);
- cpuset_unlock();
panic("Out of memory and no killable processes...\n");
}
@@ -508,7 +506,6 @@
out:
read_unlock(&tasklist_lock);
- cpuset_unlock();
/*
* Give "p" a good chance of killing itself before we