From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 33D7EC43381 for ; Tue, 12 Mar 2019 01:22:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 001BC214AF for ; Tue, 12 Mar 2019 01:22:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726544AbfCLBWc (ORCPT ); Mon, 11 Mar 2019 21:22:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54204 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726406AbfCLBWc (ORCPT ); Mon, 11 Mar 2019 21:22:32 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 17877307D848; Tue, 12 Mar 2019 01:22:32 +0000 (UTC) Received: from ming.t460p (ovpn-8-22.pek2.redhat.com [10.72.8.22]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 022EF600CD; Tue, 12 Mar 2019 01:22:25 +0000 (UTC) Date: Tue, 12 Mar 2019 09:22:21 +0800 From: Ming Lei To: Christoph Hellwig Cc: Jens Axboe , linux-block@vger.kernel.org, ris Ostrovsky , Juergen Gross , xen-devel@lists.xenproject.org, Omar Sandoval Subject: Re: [PATCH 2/6] block: don't merge adjacent bvecs to one segment in bio blk_queue_split Message-ID: <20190312012220.GC28841@ming.t460p> References: <20190309013737.27741-1-ming.lei@redhat.com> <20190309013737.27741-3-ming.lei@redhat.com> <20190311142106.GB7850@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190311142106.GB7850@lst.de> User-Agent: Mutt/1.9.1 (2017-09-22) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Tue, 12 Mar 2019 01:22:32 +0000 (UTC) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Mon, Mar 11, 2019 at 03:21:06PM +0100, Christoph Hellwig wrote: > On Sat, Mar 09, 2019 at 09:37:33AM +0800, Ming Lei wrote: > > For normal filesystem IO, each page is added via blk_add_page(), > > in which bvec(page) merge has been handled already, and basically > > not possible to merge two adjacent bvecs in one bio. > > > > So not try to merge two adjacent bvecs in blk_queue_split(), also add > > check if one page is mergeable to current bvec in bio_add_page() for > > avoiding to break XEN. > > Isn't this two entirely different things? Both look good to me, > but I don't understand why this is one patch vs two. You are right, it should have been two things logically. Thanks, Ming