Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753066AbYJ2Ihl (ORCPT ); Wed, 29 Oct 2008 04:37:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752724AbYJ2Ihd (ORCPT ); Wed, 29 Oct 2008 04:37:33 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:41405 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752707AbYJ2Ihc (ORCPT ); Wed, 29 Oct 2008 04:37:32 -0400 Date: Wed, 29 Oct 2008 09:37:13 +0100 From: Ingo Molnar To: FUJITA Tomonori Cc: jens.axboe@oracle.com, jeremy@goop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] x86: replace BIO_VMERGE_BOUNDARY with BIOVEC_PHYS_MERGEABLE Message-ID: <20081029083713.GE6364@elte.hu> References: <20081027094111.GU22217@kernel.dk> <4905A961.9000603@goop.org> <20081027115659.GZ22217@kernel.dk> <20081029080603J.fujita.tomonori@lab.ntt.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081029080603J.fujita.tomonori@lab.ntt.co.jp> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00,DNS_FROM_SECURITYSAGE autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] 0.0 DNS_FROM_SECURITYSAGE RBL: Envelope sender in blackholes.securitysage.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1519 Lines: 44 * FUJITA Tomonori wrote: > On Mon, 27 Oct 2008 12:57:00 +0100 > Jens Axboe wrote: > > > On Mon, Oct 27 2008, Jeremy Fitzhardinge wrote: > > > Jens Axboe wrote: > > > >Pretty much baffles me as well, xen should just need to do > > > > > > > >#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) 0 > > > > > > > > > > It needs to be a runtime switch, since we only want to do this when > > > actually running under Xen. Also, its possible that the two pages might > > > actually be physically contiguous, so they could be merged anyway. > > > > Alright, then add a xen_biovec_phys_mergeable(vec1, vec2) in the xen > > code that actually checks this for real. You can add your switch there > > as well. Then put the BIOVEC_PHYS_MERGEABLE() in the xen arch includes, > > done. > > > > What Tomo is saying is that this has nothing to do with virtual merging, > > and he's right. > > Yeah, overriding BIOVEC_PHYS_MERGEABLE perfectly works for Xen. And it > is not related with BIO_VMERGE_BOUNDARY at all. > > Ingo, please put this patch into your tree: > > http://marc.info/?l=linux-kernel&m=122482703716620&w=2 does it have any dependency on: Subject: [PATCH 1/2] bio: define __BIOVEC_PHYS_MERGEABLE ? Ingo -- 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/