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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 34D2DC00449 for ; Wed, 3 Oct 2018 14:58:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E74142082A for ; Wed, 3 Oct 2018 14:58:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E74142082A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=acm.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726933AbeJCVrl (ORCPT ); Wed, 3 Oct 2018 17:47:41 -0400 Received: from mail-pf1-f193.google.com ([209.85.210.193]:40963 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726748AbeJCVrl (ORCPT ); Wed, 3 Oct 2018 17:47:41 -0400 Received: by mail-pf1-f193.google.com with SMTP id m77-v6so1810384pfi.8; Wed, 03 Oct 2018 07:58:55 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:mime-version:content-transfer-encoding; bh=dTGBLSnh0CRsokaJ9tV8vfG+xryHa8lau6FyTzHJLoo=; b=Cy92NeL3FpTvkcJGYFlSP32uZ0m47hE05zpSTeVCi2khvBFyPZlpQoZBDrsVq8+6RF bBgjJisJdpel15+kQ+79YGjJw1ZTjaA1un2q4wPtwGmf3bxdjbprTmOZ33eID8FimSus uRHydO96mb+pvHSo/LllQnGqG5YyK8t+phxbrNIQwjepqDZ7fwsl72XemirCVbF50ukd Sa0NeYlM2Air0xrcWpaY9vUKpAR+Kr59+T+hX4RuRGGY2Qsx99YFVy3+eGT9v0jPAEQn CNSV8HDpsCyj1aNxmYrUMkpyyV3Hg47ffNZQj7o2AHrj6dNrDmezw25QjVKx3jH8Dc/O k3fg== X-Gm-Message-State: ABuFfojAjGuUkH9PXN7XdCLc0PTpqGT5kHhuGZb9y5DyhJU92CyrhspV tLCGiOHA8MJN7rBazrwIh+Q= X-Google-Smtp-Source: ACcGV61lpSONFeHu2ZWyL/DWU6q3o12cwSPEsV7iPKSO1bW3JfMlqh5lbod1a46ErUJWJ02Fsnh7Xw== X-Received: by 2002:a63:ce56:: with SMTP id r22-v6mr1694494pgi.217.1538578734653; Wed, 03 Oct 2018 07:58:54 -0700 (PDT) Received: from ?IPv6:2620:15c:2cd:203:5cdc:422c:7b28:ebb5? ([2620:15c:2cd:203:5cdc:422c:7b28:ebb5]) by smtp.gmail.com with ESMTPSA id d65-v6sm3734098pfe.42.2018.10.03.07.58.53 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 03 Oct 2018 07:58:53 -0700 (PDT) Message-ID: <1538578732.205649.0.camel@acm.org> Subject: Re: [PATCH] block: BFQ default for single queue devices From: Bart Van Assche To: Christoph Hellwig , Damien Le Moal Cc: Linus Walleij , Artem Bityutskiy , Paolo Valente , Jens Axboe , linux-block , linux-mmc , "linux-mtd@lists.infradead.org" , Pavel Machek , Ulf Hansson , Richard Weinberger , Adrian Hunter , Jan Kara , "aherrmann@suse.com" , "mgorman@suse.com" , Chunyan Zhang , "linux-kernel@vger.kernel.org" , "bfq-iosched@googlegroups.com" , "oleksandr@natalenko.name" , Mark Brown Date: Wed, 03 Oct 2018 07:58:52 -0700 In-Reply-To: <20181003125146.GA9313@infradead.org> References: <20181002124329.21248-1-linus.walleij@linaro.org> <05fdbe23-ec01-895f-e67e-abff85c1ece2@kernel.dk> <1538550325.14984.108.camel@gmail.com> <20181003125146.GA9313@infradead.org> Content-Type: text/plain; charset="UTF-7" X-Mailer: Evolution 3.26.2-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2018-10-03 at 05:51 -0700, Christoph Hellwig wrote: +AD4 On Wed, Oct 03, 2018 at 07:42:15AM +-0000, Damien Le Moal wrote: +AD4 +AD4 Of note also is that host-managed like sequential zone devices are also likely +AD4 +AD4 to show up soon with the work being done in the NVMe standard on the new +ACI-Zoned +AD4 +AD4 namespace+ACI feature proposal. These devices will also require a scheduler like +AD4 +AD4 mq-deadline guaranteeing per-zone in-order delivery of sequential write +AD4 +AD4 requests. Looking only at the number of queues of the device is not enough to +AD4 +AD4 choose the best (most reasonnable/appropriate) scheduler. +AD4 +AD4 We actually have a plan to avoid the need for a non-reordering scheduler +AD4 there (including a Linux prototype for it). Lets see if it survives the +AD4 committee. Has the work with the T10 committee to standardize the SCSI equivalent of anonymous writes already started? Thanks, Bart.