From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id 3E6027CA0 for ; Sun, 5 Jun 2016 00:17:08 -0500 (CDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay3.corp.sgi.com (Postfix) with ESMTP id C72E7AC004 for ; Sat, 4 Jun 2016 22:17:04 -0700 (PDT) Received: from 1wt.eu (wtarreau.pck.nerim.net [62.212.114.60]) by cuda.sgi.com with ESMTP id wlPbwhlMC4POCPfm for ; Sat, 04 Jun 2016 22:17:01 -0700 (PDT) Date: Sun, 5 Jun 2016 07:16:54 +0200 From: Willy Tarreau Subject: Re: XFS hole punch races Message-ID: <20160605051654.GA20713@1wt.eu> References: <20160322155740.GB28772@quack.suse.cz> <1465060270.2847.149.camel@decadent.org.uk> <20160604232800.GW26977@dastard> <1465089572.2847.180.camel@decadent.org.uk> <20160605021654.GX26977@dastard> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20160605021654.GX26977@dastard> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: Jan Kara , Ben Hutchings , stable@vger.kernel.org, xfs@oss.sgi.com Dave, On Sun, Jun 05, 2016 at 12:16:54PM +1000, Dave Chinner wrote: > On Sun, Jun 05, 2016 at 02:19:32AM +0100, Ben Hutchings wrote: > > On Sun, 2016-06-05 at 09:28 +1000, Dave Chinner wrote: > > > You do realise that this sort of backport effectively makes the > > > stable kernels unsupportable by the upstream XFS developers? You're > > > taking random changes from the upstream kernel until the kernel > > > compiles, and then mostly hoping that it works. > > > > I'm applying slightly more intelligence than that, but of course I'm > > not an XFS developer. > > Sorry, Ben, I didn't mean to imply you hadn't done your due diligence > properly. It's more a case of lots of things around these patches > also changed, and from that perspective the changes are effective a > random selection of changes spread across several years of > development. > > It's subtle things, like changes to how IO completion is processed > (especially for AIO), etc that the backported code might depend on > for correct behaviour but aren't in the older kernels. These sorts > of subtle problems are typically only discovered by users with > uncommon applications and/or load.... Does this mean that as a rule of thumb we'd rather avoid backporting XFS fixes unless they seem really obvious (or at all) ? Thanks, Willy _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs