Merge tag 'v2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into for-linus

1 files changed, 7 insertions, 1 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 8859a41806dd..e3378e8d3a5c 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1291,8 +1291,14 @@ __acquires(&gcwq->lock)
                         return true;
                 spin_unlock_irq(&gcwq->lock);
 
-                /* CPU has come up in between, retry migration */
+                /*
+                 * We've raced with CPU hot[un]plug.  Give it a breather
+                 * and retry migration.  cond_resched() is required here;
+                 * otherwise, we might deadlock against cpu_stop trying to
+                 * bring down the CPU on non-preemptive kernel.
+                 */
                 cpu_relax();
+                cond_resched();
         }
 }