From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id AA7DD5F0040 for ; Thu, 21 Oct 2010 08:54:06 -0400 (EDT) Received: from localhost.localdomain by digidescorp.com (Cipher TLSv1:RC4-MD5:128) (MDaemon PRO v10.1.1) with ESMTP id md50001457164.msg for ; Thu, 21 Oct 2010 07:54:04 -0500 From: "Steven J. Magnani" Subject: [PATCH] nommu: yield CPU periodically while disposing large VM Date: Thu, 21 Oct 2010 07:53:55 -0500 Message-Id: <1287665635-7925-1-git-send-email-steve@digidescorp.com> Sender: owner-linux-mm@kvack.org To: linux-mm@kvack.org Cc: dhowells@redhat.com, linux-kernel@vger.kernel.org, "Steven J. Magnani" List-ID: 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 --- diff -uprN a/mm/nommu.c b/mm/nommu.c --- a/mm/nommu.c 2010-10-21 07:42:23.000000000 -0500 +++ b/mm/nommu.c 2010-10-21 07:46:50.000000000 -0500 @@ -1656,6 +1656,7 @@ SYSCALL_DEFINE2(munmap, unsigned long, a void exit_mmap(struct mm_struct *mm) { struct vm_area_struct *vma; + unsigned long next_yield = jiffies + HZ; if (!mm) return; @@ -1668,6 +1669,11 @@ void exit_mmap(struct mm_struct *mm) mm->mmap = vma->vm_next; delete_vma_from_mm(vma); delete_vma(mm, vma); + /* Yield periodically to prevent watchdog timeout */ + if (time_after(jiffies, next_yield)) { + cond_resched(); + next_yield = jiffies + HZ; + } } kleave(""); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org