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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 C86A6C04EB8 for ; Fri, 30 Nov 2018 08:00:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 962032146D for ; Fri, 30 Nov 2018 08:00:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 962032146D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-block-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726706AbeK3TIl (ORCPT ); Fri, 30 Nov 2018 14:08:41 -0500 Received: from verein.lst.de ([213.95.11.211]:48686 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726651AbeK3TIl (ORCPT ); Fri, 30 Nov 2018 14:08:41 -0500 Received: by newverein.lst.de (Postfix, from userid 2407) id CC50C68BDF; Fri, 30 Nov 2018 09:00:13 +0100 (CET) Date: Fri, 30 Nov 2018 09:00:13 +0100 From: Christoph Hellwig To: Keith Busch Cc: Christoph Hellwig , Jens Axboe , Sagi Grimberg , Max Gurtovoy , linux-nvme@lists.infradead.org, linux-block@vger.kernel.org Subject: Re: [PATCH 01/13] block: move queues types to the block layer Message-ID: <20181130080013.GB18936@lst.de> References: <20181129191310.9795-1-hch@lst.de> <20181129191310.9795-2-hch@lst.de> <20181129201914.GB9377@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181129201914.GB9377@localhost.localdomain> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, Nov 29, 2018 at 01:19:14PM -0700, Keith Busch wrote: > On Thu, Nov 29, 2018 at 08:12:58PM +0100, Christoph Hellwig wrote: > > +enum hctx_type { > > + HCTX_TYPE_DEFAULT, /* all I/O not otherwise accounted for */ > > + HCTX_TYPE_READ, /* just for READ I/O */ > > + HCTX_TYPE_POLL, /* polled I/O of any kind */ > > + > > + HCTX_MAX_TYPES, > > }; > > Well, there goes my plan to use this with Weighted-Round-Robin NVMe IO > queues! Wo between what do you even want to round robin? If it is between reads and writes that's easy. If we want priority reads or writes (separate from polling) that's also still fairly easily. Btw, one thing I wanted to try once I get hold of the right hardware is to mark the poll queues as priority queues and see if that makes any differents in poll IOPS/latency. From mboxrd@z Thu Jan 1 00:00:00 1970 From: hch@lst.de (Christoph Hellwig) Date: Fri, 30 Nov 2018 09:00:13 +0100 Subject: [PATCH 01/13] block: move queues types to the block layer In-Reply-To: <20181129201914.GB9377@localhost.localdomain> References: <20181129191310.9795-1-hch@lst.de> <20181129191310.9795-2-hch@lst.de> <20181129201914.GB9377@localhost.localdomain> Message-ID: <20181130080013.GB18936@lst.de> On Thu, Nov 29, 2018@01:19:14PM -0700, Keith Busch wrote: > On Thu, Nov 29, 2018@08:12:58PM +0100, Christoph Hellwig wrote: > > +enum hctx_type { > > + HCTX_TYPE_DEFAULT, /* all I/O not otherwise accounted for */ > > + HCTX_TYPE_READ, /* just for READ I/O */ > > + HCTX_TYPE_POLL, /* polled I/O of any kind */ > > + > > + HCTX_MAX_TYPES, > > }; > > Well, there goes my plan to use this with Weighted-Round-Robin NVMe IO > queues! Wo between what do you even want to round robin? If it is between reads and writes that's easy. If we want priority reads or writes (separate from polling) that's also still fairly easily. Btw, one thing I wanted to try once I get hold of the right hardware is to mark the poll queues as priority queues and see if that makes any differents in poll IOPS/latency.