Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753645AbdDJPPh (ORCPT ); Mon, 10 Apr 2017 11:15:37 -0400 Received: from esa1.hgst.iphmx.com ([68.232.141.245]:37786 "EHLO esa1.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751396AbdDJPPf (ORCPT ); Mon, 10 Apr 2017 11:15:35 -0400 X-IronPort-AV: E=Sophos;i="5.37,182,1488816000"; d="scan'208";a="111907893" From: Bart Van Assche To: "aherrmann@suse.com" , "paolo.valente@linaro.org" CC: "linux-kernel@vger.kernel.org" , "linux-block@vger.kernel.org" , "axboe@kernel.dk" Subject: Re: bfq-mq performance comparison to cfq Thread-Topic: bfq-mq performance comparison to cfq Thread-Index: AQHSsdm2Eefag5Pjc0GpWkttf0cWdaG+XYiAgABZWQA= Date: Mon, 10 Apr 2017 15:15:31 +0000 Message-ID: <1491837330.4199.1.camel@sandisk.com> References: <20170410090538.GA11473@suselix.suse.de> <82BCEB46-8D05-42DA-AE06-3426895A7842@linaro.org> In-Reply-To: <82BCEB46-8D05-42DA-AE06-3426895A7842@linaro.org> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: suse.com; dkim=none (message not signed) header.d=none;suse.com; dmarc=none action=none header.from=sandisk.com; x-ms-exchange-messagesentrepresentingtype: 1 x-originating-ip: [63.163.107.100] x-microsoft-exchange-diagnostics: 1;CY1PR0401MB1536;7:B3PoTeSk3RL+LrRy1zQLXe9wlcDKidw+FbCNDr6ZgKLsJ42/p2R9b5sr5GpSbPJakxbX2UW5kMoxhY8BsUDDS2FZw4gHEGBkQSLg8821vsSDq4tC2PZDI65jKw+a1nmptfLaaluho5apD/jnVuk+4egu5nWPVmR3kV276sghb909g3wn/4DTTTuMUqsFgT8WEaVAmvnroNa0abmmrwTWlpQISC+wcuX17bP5tTD3kxt67zsoK/q01lT9XHnVtkkyT9radPCJrIHJ8RYnAzmgIW0KPHxwjrg5P2185HNYt3ZNVNkzzLbPIbd/GWIzakyOw/5/u1OVAKNdRyhwNRX06g==;20:VSDgVq1I3OeAzclz4a846I+sE32bbIGO87g0Qbe3CQ1QWwtSJl8RHyiiZfE2TCiYciEvA7HuzkDv2/H63erWN8oKIMLyqNiD8JOqUoDw4l+hE4S0M17kKZ1j2ekcSBMvd0uBWelx1QytcdBO6n9zTMBgeLXjudeYFrSpNkN8XUY= x-ms-office365-filtering-correlation-id: 556126e7-5afb-4e87-fb42-08d480246e23 x-ms-office365-filtering-ht: Tenant x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:(22001)(2017030254075)(48565401081)(201703131423075)(201703031133081);SRVR:CY1PR0401MB1536; wdcipoutbound: EOP-TRUE x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:(278428928389397); x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(6040450)(601004)(2401047)(8121501046)(5005006)(3002001)(93006095)(93001095)(10201501046)(6055026)(6041248)(201703131423075)(201702281528075)(201703061421075)(20161123564025)(20161123560025)(20161123555025)(20161123562025)(6072148);SRVR:CY1PR0401MB1536;BCL:0;PCL:0;RULEID:;SRVR:CY1PR0401MB1536; x-forefront-prvs: 027367F73D x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(979002)(6009001)(39400400002)(39850400002)(39410400002)(39450400003)(39860400002)(39840400002)(377424004)(24454002)(33646002)(76176999)(189998001)(54356999)(50986999)(8936002)(5660300001)(66066001)(3846002)(2900100001)(305945005)(7736002)(3660700001)(8676002)(122556002)(86362001)(3280700002)(2906002)(106356001)(99286003)(6506006)(81166006)(77096006)(6436002)(6512007)(53936002)(54906002)(4326008)(38730400002)(102836003)(6246003)(6116002)(2501003)(229853002)(25786009)(36756003)(103116003)(6486002)(2950100002)(969003)(989001)(999001)(1009001)(1019001);DIR:OUT;SFP:1102;SCL:1;SRVR:CY1PR0401MB1536;H:CY1PR0401MB1536.namprd04.prod.outlook.com;FPR:;SPF:None;MLV:ovrnspm;PTR:InfoNoRecords;LANG:en; spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="iso-8859-1" Content-ID: MIME-Version: 1.0 X-OriginatorOrg: sandisk.com X-MS-Exchange-CrossTenant-originalarrivaltime: 10 Apr 2017 15:15:31.9549 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: b61c8803-16f3-4c35-9b17-6f65f441df86 X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY1PR0401MB1536 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id v3AFFgPm004536 Content-Length: 997 Lines: 20 On Mon, 2017-04-10 at 11:55 +0200, Paolo Valente wrote: > That said, if you do always want maximum throughput, even at the > expense of latency, then just switch off low-latency heuristics, i.e., > set low_latency to 0. Depending on the device, setting slice_ilde to > 0 may help a lot too (as well as with CFQ). If the throughput is > still low also after forcing BFQ to an only-throughput mode, then you > hit some bug, and I'll have a little more work to do ... Hello Paolo, Has it been considered to make applications tell the I/O scheduler whether to optimize for latency or for throughput? It shouldn't be that hard for window managers and shells to figure out whether or not a new application that is being started is interactive or not. This would require a mechanism that allows applications to provide such information to the I/O scheduler. Wouldn't that be a better approach than the I/O scheduler trying to guess whether or not an application is an interactive application? Bart.