[086/127] nommu: yield CPU while disposing VM

From: Greg KH
Date: Tue Dec 07 2010 - 19:56:42 EST


2.6.32-stable review patch. If anyone has any objections, please let us know.

------------------

From: Steven J. Magnani <steve@xxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxx>
Cc: Greg Ungerer <gerg@xxxxxxxxxxxx>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
mm/nommu.c | 1 +
1 file changed, 1 insertion(+)

--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1615,6 +1615,7 @@ void exit_mmap(struct mm_struct *mm)
mm->mmap = vma->vm_next;
delete_vma_from_mm(vma);
delete_vma(mm, vma);
+ cond_resched();
}

kleave("");


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