Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760821AbZCZTFS (ORCPT ); Thu, 26 Mar 2009 15:05:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760296AbZCZTEG (ORCPT ); Thu, 26 Mar 2009 15:04:06 -0400 Received: from brick.kernel.dk ([93.163.65.50]:48966 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759730AbZCZTDk (ORCPT ); Thu, 26 Mar 2009 15:03:40 -0400 Date: Thu, 26 Mar 2009 20:03:37 +0100 From: Jens Axboe To: Hugh Dickins Cc: Ric Wheeler , Jeff Garzik , Linus Torvalds , Theodore Tso , Ingo Molnar , Alan Cox , Arjan van de Ven , Andrew Morton , Peter Zijlstra , Nick Piggin , David Rees , Jesper Krogh , Linux Kernel Mailing List Subject: Re: Linux 2.6.29 Message-ID: <20090326190337.GM27476@kernel.dk> References: <20090325194341.GB27476@kernel.dk> <49CA8ADA.3040709@redhat.com> <20090325195747.GC27476@kernel.dk> <20090326085748.GH27476@kernel.dk> <20090326154610.GH27476@kernel.dk> <20090326183254.GI27476@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1284 Lines: 33 On Thu, Mar 26 2009, Hugh Dickins wrote: > On Thu, 26 Mar 2009, Jens Axboe wrote: > > On Thu, Mar 26 2009, Hugh Dickins wrote: > > > > > > So, directing a barrier (WRITE_BARRIER or DISCARD_BARRIER) to a range > > > of sectors in one partition interposes a barrier into the queue of I/O > > > across (all partitions of) that whole device. > > > > Correct > > > > > I think that's not how filesystems really want barriers to behave, > > > and might tend to discourage us from using barriers more freely. > > > But I have zero appreciation of whether it's a significant issue > > > worth non-trivial change - just wanted to get it out into the open. > > > > Per-partition definitely makes sense. The problem is that we do sorting > > on a per-device basis right now. But it's a good point, I'll try and > > take a look at how much work it would be to make it per-partition > > instead. It wont be trivial :-) > > Thanks, that would be interesting. > Trivial bores you anyway, doesn't it? You're a good motivator, Hugh! -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/