From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932570AbbELIzn (ORCPT ); Tue, 12 May 2015 04:55:43 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:50357 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932392AbbELIzi (ORCPT ); Tue, 12 May 2015 04:55:38 -0400 MIME-Version: 1.0 In-Reply-To: <20150512072523.GC25438@infradead.org> References: <1430932106-17451-1-git-send-email-ming.lei@canonical.com> <1430932106-17451-4-git-send-email-ming.lei@canonical.com> <20150507071707.GB7595@infradead.org> <20150511072000.GB19488@infradead.org> <20150512072523.GC25438@infradead.org> Date: Tue, 12 May 2015 16:55:36 +0800 Message-ID: Subject: Re: [PATCH v3 3/4] block: loop: use kthread_work From: Ming Lei To: Christoph Hellwig Cc: Linux Kernel Mailing List , Dave Kleikamp , Jens Axboe , Zach Brown , Maxim Patlasov , Andrew Morton , Alexander Viro , Tejun Heo Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 12, 2015 at 3:25 PM, Christoph Hellwig wrote: > On Mon, May 11, 2015 at 09:12:56PM +0800, Ming Lei wrote: >> For non-AIO case, single thread has been used for long long time, >> and it was just converted to work in v4.0, which has caused performance >> regression for fedora live booting already. In discussion[1], even though >> submitting I/O via work concurrently can improve random IO throughput, >> meantime it may hurt sequential IO performance, so maybe better to restore >> to single thread behaviour. > > Then justify the change based on the non-aio use case and document that > in the changelog. OK, will add that in v4. Thanks, Ming