From a28c2bb7f58fad804d4673eb37b7c0436b945f15 Mon Sep 17 00:00:00 2001
From: "Steven J. Magnani" <steve@digidescorp.com>
Date: Wed, 24 Nov 2010 12:56:54 -0800
Subject: [PATCH] nommu: yield CPU while disposing VM

commit 04c3496152394d17e3bc2316f9731ee3e8a026bc upstream.

Depending on processor speed, page size, and the amount of memory a
process is allowed to amass, cleanup of a large VM may freeze the system
for many seconds.  This can result in a watchdog timeout.

Make sure other tasks receive some service when cleaning up large VMs.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 mm/nommu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/nommu.c b/mm/nommu.c
index e48b38c521e4..3e1854887418 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1673,6 +1673,7 @@ void exit_mmap(struct mm_struct *mm)
 		mm->mmap = vma->vm_next;
 		delete_vma_from_mm(vma);
 		delete_vma(mm, vma);
+		cond_resched();
 	}
 
 	kleave("");
-- 
2.39.5