Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946197Ab2ESA7q (ORCPT ); Fri, 18 May 2012 20:59:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:13470 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759853Ab2ESA7n (ORCPT ); Fri, 18 May 2012 20:59:43 -0400 Date: Sat, 19 May 2012 01:59:32 +0100 From: Alasdair G Kergon To: Tejun Heo Cc: koverstreet@google.com, axboe@kernel.dk, dm-devel@redhat.com, linux-kernel@vger.kernel.org, linux-bcache@vger.kernel.org, linux-fsdevel@vger.kernel.org, agk@redhat.com Subject: Re: [dm-devel] [PATCH 12/13] Make generic_make_request handle arbitrarily large bios Message-ID: <20120519005932.GM29330@agk-dp.fab.redhat.com> Mail-Followup-To: Tejun Heo , koverstreet@google.com, axboe@kernel.dk, dm-devel@redhat.com, linux-kernel@vger.kernel.org, linux-bcache@vger.kernel.org, linux-fsdevel@vger.kernel.org, agk@redhat.com References: <1114e7019b0055fc09a54b59b36398d5c54f5e32.1337308722.git.koverstreet@google.com> <20120518175216.GL19388@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120518175216.GL19388@google.com> Organization: Red Hat UK Ltd. Registered in England and Wales, number 03798903. Registered Office: 64 Baker Street, 4th floor, London, W1U 7DF. User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 594 Lines: 16 On Fri, May 18, 2012 at 10:52:16AM -0700, Tejun Heo wrote: > Does this by any chance allow killing ->merge_bvec_fn()? merge_bvec also has an impact on efficiency. Why create a too-large bio in the first place if it's only going to have to get split up again? If a change like this goes in, the various trade-offs should be re-examined. Alasdair -- 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/