From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753222Ab2ABQWB (ORCPT ); Mon, 2 Jan 2012 11:22:01 -0500 Received: from mx1.redhat.com ([209.132.183.28]:24434 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752728Ab2ABQWA (ORCPT ); Mon, 2 Jan 2012 11:22:00 -0500 Message-ID: <4F01D997.1070501@redhat.com> Date: Mon, 02 Jan 2012 18:21:43 +0200 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:8.0) Gecko/20111115 Thunderbird/8.0 MIME-Version: 1.0 To: Christoph Hellwig CC: Stefan Hajnoczi , Minchan Kim , Rusty Russell , Chris Wright , Jens Axboe , Stefan Hajnoczi , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Vivek Goyal Subject: Re: [PATCH 0/6][RFC] virtio-blk: Change I/O path from request to BIO References: <1324429254-28383-1-git-send-email-minchan@kernel.org> <20111222234135.GB7056@barrios-laptop.redhat.com> <20120102161803.GA32365@infradead.org> In-Reply-To: <20120102161803.GA32365@infradead.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/02/2012 06:18 PM, Christoph Hellwig wrote: > On Sun, Jan 01, 2012 at 04:45:42PM +0000, Stefan Hajnoczi wrote: > > win. The fact that you added batching suggests there is some benefit > > to what the request-based code path does. So find out what's good > > about the request-based code path and how to get the best of both > > worlds. > > Batching pretty much always is a winner. The maximum bio size is small > enough that we'll frequently see multiple contiguos bios. Maybe the maximum bio size should be increased then; not that I disagree with your conclusion. > Because of > that the Md layer fo example uses the same kind of batching. I've tried > to make this more general by passing a bio list to ->make_request and > make the on-stack plugging work on bios, but in the timeslice I had > available for that I didn't manage to actually make it work. > > -- error compiling committee.c: too many arguments to function