Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753243AbbF3OVq (ORCPT ); Tue, 30 Jun 2015 10:21:46 -0400 Received: from smtp.ctxuk.citrix.com ([185.25.65.24]:54914 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751311AbbF3OVi (ORCPT ); Tue, 30 Jun 2015 10:21:38 -0400 X-IronPort-AV: E=Sophos;i="5.15,378,1432598400"; d="scan'208";a="1111341" Message-ID: <5592A5EF.2050005@citrix.com> Date: Tue, 30 Jun 2015 15:21:35 +0100 From: Marcus Granado User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Bob Liu , Arianna Avanzini CC: , , , Christoph Hellwig , , , , Jonathan Davies , Rafal Mielniczuk Subject: Re: [Xen-devel] [PATCH RFC v2 0/5] Multi-queue support for xen-blkfront and xen-blkback References: <1410479844-2864-1-git-send-email-avanzini.arianna@gmail.com> <20141001202721.GF12581@laptop.dumpdata.com> <20150428073646.GA16022@infradead.org> <553F3ADF.3000301@gmail.com> <555327A5.1060200@oracle.com> In-Reply-To: <555327A5.1060200@oracle.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-DLP: AMS1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2781 Lines: 70 On 13/05/15 11:29, Bob Liu wrote: > > On 04/28/2015 03:46 PM, Arianna Avanzini wrote: >> Hello Christoph, >> >> Il 28/04/2015 09:36, Christoph Hellwig ha scritto: >>> What happened to this patchset? >>> >> >> It was passed on to Bob Liu, who published a follow-up patchset here: https://lkml.org/lkml/2015/2/15/46 >> > > Right, and then I was interrupted by another xen-block feature: 'multi-page' ring. > Will back on this patchset soon. Thank you! > > -Bob > Hi, Our measurements for the multiqueue patch indicate a clear improvement in iops when more queues are used. The measurements were obtained under the following conditions: - using blkback as the dom0 backend with the multiqueue patch applied to a dom0 kernel 4.0 on 8 vcpus. - using a recent Ubuntu 15.04 kernel 3.19 with multiqueue frontend applied to be used as a guest on 4 vcpus - using a micron RealSSD P320h as the underlying local storage on a Dell PowerEdge R720 with 2 Xeon E5-2643 v2 cpus. - fio 2.2.7-22-g36870 as the generator of synthetic loads in the guest. We used direct_io to skip caching in the guest and ran fio for 60s reading a number of block sizes ranging from 512 bytes to 4MiB. Queue depth of 32 for each queue was used to saturate individual vcpus in the guest. We were interested in observing storage iops for different values of block sizes. Our expectation was that iops would improve when increasing the number of queues, because both the guest and dom0 would be able to make use of more vcpus to handle these requests. These are the results (as aggregate iops for all the fio threads) that we got for the conditions above with sequential reads: fio_threads io_depth block_size 1-queue_iops 8-queue_iops 8 32 512 158K 264K 8 32 1K 157K 260K 8 32 2K 157K 258K 8 32 4K 148K 257K 8 32 8K 124K 207K 8 32 16K 84K 105K 8 32 32K 50K 54K 8 32 64K 24K 27K 8 32 128K 11K 13K 8-queue iops was better than single queue iops for all the block sizes. There were very good improvements as well for sequential writes with block size 4K (from 80K iops with single queue to 230K iops with 8 queues), and no regressions were visible in any measurement performed. Marcus -- 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/