From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vivek Goyal Subject: Re: Query about DIO/AIO WRITE throttling and ext4 serialization Date: Thu, 2 Jun 2011 10:17:16 -0400 Message-ID: <20110602141716.GD18712@redhat.com> References: <20110601215049.GC17449@redhat.com> <20110602012209.GQ561@dastard> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org To: Dave Chinner Return-path: Received: from mx1.redhat.com ([209.132.183.28]:19543 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750970Ab1FBORV (ORCPT ); Thu, 2 Jun 2011 10:17:21 -0400 Content-Disposition: inline In-Reply-To: <20110602012209.GQ561@dastard> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Jun 02, 2011 at 11:22:09AM +1000, Dave Chinner wrote: > On Wed, Jun 01, 2011 at 05:50:49PM -0400, Vivek Goyal wrote: > > Hi, > > > > If I throttle a DIO/AIO WRITE bio at block device in a cgroup, will it > > lead to any kind of serialization of ext4 file system. IOW, is there any > > filesystem operation which will wait for that DIO/AIO WRITE to finish > > before other filesystem can make progress (fsync, journalling etc?) > > Truncate? > > (XFS explicitly serialises truncate against in flight DIO, > regardless of whether ext4 does.) > Dave, Does this serialization happens against that particular inode on which truncate has been called? If yes, then I think I will still be fine as in common use case I am not expecting much sharing of inodes across cgroups. Thanks Vivek