Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752389Ab2E2CIV (ORCPT ); Mon, 28 May 2012 22:08:21 -0400 Received: from ipmail06.adl6.internode.on.net ([150.101.137.145]:10620 "EHLO ipmail06.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751885Ab2E2CIS (ORCPT ); Mon, 28 May 2012 22:08:18 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ak0JAKIuxE95LJr7/2dsb2JhbABEtDMEgSSBCIIXAQEFOhwjEAgDDgouFCUDIROICrgjFIpvT4QCYAOVFokfhlOCcg Date: Tue, 29 May 2012 12:08:15 +1000 From: Dave Chinner To: Tejun Heo Cc: Mikulas Patocka , Alasdair G Kergon , Kent Overstreet , Mike Snitzer , linux-kernel@vger.kernel.org, linux-bcache@vger.kernel.org, dm-devel@redhat.com, linux-fsdevel@vger.kernel.org, axboe@kernel.dk, yehuda@hq.newdream.net, vgoyal@redhat.com, bharrosh@panasas.com, sage@newdream.net, drbd-dev@lists.linbit.com, Dave Chinner , tytso@google.com, "Martin K. Petersen" Subject: Re: [PATCH v3 14/16] Gut bio_add_page() Message-ID: <20120529020815.GB5091@dastard> References: <1337977539-16977-1-git-send-email-koverstreet@google.com> <1337977539-16977-15-git-send-email-koverstreet@google.com> <20120525204651.GA24246@redhat.com> <20120525210944.GB14196@google.com> <20120525223937.GF5761@agk-dp.fab.redhat.com> <20120528202839.GA18537@dhcp-172-17-108-109.mtv.corp.google.com> <20120528213839.GB18537@dhcp-172-17-108-109.mtv.corp.google.com> <20120528230208.GA20954@dhcp-172-17-108-109.mtv.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120528230208.GA20954@dhcp-172-17-108-109.mtv.corp.google.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1255 Lines: 32 On Tue, May 29, 2012 at 08:02:08AM +0900, Tejun Heo wrote: > (cc'ing Martin K. Petersen, hi!) > > On Tue, May 29, 2012 at 06:38:39AM +0900, Tejun Heo wrote: > > > With this patchset, you don't have to expose all the limits. You can > > > expose just a few most useful limits to avoid bio split in the cases > > > described above. > > > > Yeah, if that actually helps, sure. From what I read, dm is already > > (ab)using merge_bvec_fn() like that anyway. > > i thought a bit more about it and the only thing which makes sense to > me is exposing the stripe granularity for striped devices - > ie. something which says "if you go across this boundary, the > performance characteristics including latency might get affected", > which should fit nicely with the rest of topology information. > Martin, adding that shouldn't be difficult, right? We already have the optimal IO size/alignment field in the topology. Doesn't this fit what you want exactly? Cheers, Dave. -- Dave Chinner david@fromorbit.com -- 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/