From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id 6B4F56B004F for ; Tue, 28 Jul 2009 17:49:43 -0400 (EDT) Received: from spaceape9.eur.corp.google.com (spaceape9.eur.corp.google.com [172.28.16.143]) by smtp-out.google.com with ESMTP id n6SLngR2027739 for ; Tue, 28 Jul 2009 22:49:43 +0100 Received: from wf-out-1314.google.com (wff28.prod.google.com [10.142.6.28]) by spaceape9.eur.corp.google.com with ESMTP id n6SLnd0D011570 for ; Tue, 28 Jul 2009 14:49:40 -0700 Received: by wf-out-1314.google.com with SMTP id 28so88192wff.12 for ; Tue, 28 Jul 2009 14:49:38 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1786ab030907281211x6e432ba6ha6afe9de73f24e0c@mail.gmail.com> References: <1786ab030907281211x6e432ba6ha6afe9de73f24e0c@mail.gmail.com> Date: Tue, 28 Jul 2009 14:49:38 -0700 Message-ID: <33307c790907281449k5e8d4f6cib2c93848f5ec2661@mail.gmail.com> Subject: Re: Bug in kernel 2.6.31, Slow wb_kupdate writeout From: Martin Bligh Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: Chad Talbott Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, wfg@mail.ustc.edu.cn, Michael Rubin , Andrew Morton , sandeen@redhat.com List-ID: > An interesting recent-ish change is "writeback: speed up writeback of > big dirty files." =A0When I revert the change to __sync_single_inode the > problem appears to go away and background writeout proceeds at disk > speed. =A0Interestingly, that code is in the git commit [2], but not in > the post to LKML. [3] =A0This is may not be the fix, but it makes this > test behave better. I'm fairly sure this is not fixing the root cause - but putting it at the h= ead rather than the tail of the queue causes the error not to starve wb_kupdate for nearly so long - as long as we keep the queue full, the bug is hidden. M. -- 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