Merge branch 'x86/urgent' into x86-mm

Merge reason: Pick up the following two fix commits.

  2be19102b7: x86, NUMA: Fix empty memblk detection in numa_cleanup_meminfo()
  765af22da8: x86-32, NUMA: Fix ACPI NUMA init broken by recent x86-64 change

Scheduled NUMA init 32/64bit unification changes depend on these.

Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 04ef830690e..e3378e8d3a5 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 inbetween, 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();
 	}
 }