From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ted Ts'o Subject: Re: [PATCH] jbd2: Use WRITE_SYNC in journal checkpoint. Date: Mon, 27 Jun 2011 12:41:58 -0400 Message-ID: <20110627164158.GD2729@thunk.org> References: <1307418559-3329-1-git-send-email-tm@tao.ma> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org, Jan Kara To: Tao Ma Return-path: Received: from li9-11.members.linode.com ([67.18.176.11]:44573 "EHLO test.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752567Ab1F0QmD (ORCPT ); Mon, 27 Jun 2011 12:42:03 -0400 Content-Disposition: inline In-Reply-To: <1307418559-3329-1-git-send-email-tm@tao.ma> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, Jun 07, 2011 at 11:49:19AM +0800, Tao Ma wrote: > From: Tao Ma > > In journal checkpoint, we write the buffer and wait for its finish. > But in cfq, the async queue has a very low priority, and in our test, > if there are too many sync queues and every queue is filled up with > requests, the write request will be delayed for quite a long time and > all the tasks which are waiting for journal space will end with errors like: Thanks, added to the ext4 patch tree. - Ted