From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 3 Oct 2018 05:51:46 -0700 From: Christoph Hellwig To: 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 Subject: Re: [PATCH] block: BFQ default for single queue devices Message-ID: <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: List-ID: On Wed, Oct 03, 2018 at 07:42:15AM +0000, Damien Le Moal wrote: > Of note also is that host-managed like sequential zone devices are also likely > to show up soon with the work being done in the NVMe standard on the new "Zoned > namespace" feature proposal. These devices will also require a scheduler like > mq-deadline guaranteeing per-zone in-order delivery of sequential write > requests. Looking only at the number of queues of the device is not enough to > choose the best (most reasonnable/appropriate) scheduler. We actually have a plan to avoid the need for a non-reordering scheduler there (including a Linux prototype for it). Lets see if it survives the committee. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH] block: BFQ default for single queue devices Date: Wed, 3 Oct 2018 05:51:46 -0700 Message-ID: <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> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: 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" List-Id: linux-mmc@vger.kernel.org On Wed, Oct 03, 2018 at 07:42:15AM +0000, Damien Le Moal wrote: > Of note also is that host-managed like sequential zone devices are also likely > to show up soon with the work being done in the NVMe standard on the new "Zoned > namespace" feature proposal. These devices will also require a scheduler like > mq-deadline guaranteeing per-zone in-order delivery of sequential write > requests. Looking only at the number of queues of the device is not enough to > choose the best (most reasonnable/appropriate) scheduler. We actually have a plan to avoid the need for a non-reordering scheduler there (including a Linux prototype for it). Lets see if it survives the committee.