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=-2.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 69061C35240 for ; Sat, 1 Feb 2020 02:10:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 400E920663 for ; Sat, 1 Feb 2020 02:10:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="WzJTUP5Y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726743AbgBACKq (ORCPT ); Fri, 31 Jan 2020 21:10:46 -0500 Received: from mail-pl1-f195.google.com ([209.85.214.195]:37872 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726548AbgBACKq (ORCPT ); Fri, 31 Jan 2020 21:10:46 -0500 Received: by mail-pl1-f195.google.com with SMTP id c23so3530388plz.4 for ; Fri, 31 Jan 2020 18:10:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=k93QIXrlhVKvP7ezICOk3caRM5BxpPtO926JL6CGXc4=; b=WzJTUP5Yd/yOi2pp6mKUiEg5Y0sTCDhOnWOow3LVm9HbMEo9yewdTOGRujYdJMrLHC di0stniZHIsZSf1ca98dPzIpwRLgU03JMXkzIp8zlJwynW6ovU+Na1fb8lQH3loT/Uis 6mfdncX2AadVERJvdPfCHeILLUGXLDmq89+uQMQ7niNSP0mkLjOjfd4OrJUYM7kdwso/ sBpoyFEA7ZXyvd2q5awC8NsO9PQIPEA7rAAcSfvkLeso2K51Hh7m8okJ1WN7z6RnBJJK Dc9wD6CjrBAnQ6fS/3e7+Gn4bkL5n9HU9Ba+lZJ+aW2mXqe8CkBiAKewUtey/GD66djp /EtQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=k93QIXrlhVKvP7ezICOk3caRM5BxpPtO926JL6CGXc4=; b=EVxtRH1/V8NxgPMBbNyZc8LOD0F+PDwxDju2bkXZlmL6eeLwli4nodoiFDYF5c/dJm VOMoxxGdRVMONLfWiJdxGZcwB4GWpZOOLk2njZfpLcFnfrbj+dWHDF6lhGKVrweiHuke P+wCBE+p6nvWcZl6R0LTUgpbRJIbEoZ3yN7jrWgjiZevfFT0b23PtbYzSZXQYunzS3ZC eWjbK25/yRT8RyTbHWjCzTGM2P6Wsdf1q0I0jHF4okecTiFZ5wkjyeCLYXy73UeLNCW8 LeNWi8dK1rrhJxDNDaG1LHdbzCE+f6GjQomrYrj24kUhmFia1UF6gH20JfetfluElBaX jkUg== X-Gm-Message-State: APjAAAUgEE4NNcRlnb2UD9VGPinvr2hCGissduzwFn1i4eEziCmUlmm2 a7ycdM5s2UsFdDKop1hHzcMVuRJmRbQ= X-Google-Smtp-Source: APXvYqzzyMS5+MJH6hdO4YgucV12idd1nE0F8fU6Mb37cO9QTx2XLAH5YCfsk+SO5RsMUbbNJvrDqw== X-Received: by 2002:a17:90a:a385:: with SMTP id x5mr5223992pjp.102.1580523044195; Fri, 31 Jan 2020 18:10:44 -0800 (PST) Received: from [192.168.1.188] ([66.219.217.145]) by smtp.gmail.com with ESMTPSA id p17sm11327441pfn.31.2020.01.31.18.10.43 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 31 Jan 2020 18:10:43 -0800 (PST) Subject: Re: [PATCH v3 0/6] add persistent submission state To: Pavel Begunkov , io-uring@vger.kernel.org, linux-kernel@vger.kernel.org References: <6492ccd2-e829-df13-ab6e-e62590375fd1@kernel.dk> <199731e7-ca3f-ea6c-0813-6aa5dec6fa66@gmail.com> <18b43ead-0056-f975-a6ed-35fb645461e9@gmail.com> From: Jens Axboe Message-ID: <1124e9e0-cf3b-767e-40a5-57297e5ec17b@kernel.dk> Date: Fri, 31 Jan 2020 19:10:41 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <18b43ead-0056-f975-a6ed-35fb645461e9@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/31/20 5:31 PM, Pavel Begunkov wrote: > On 01/02/2020 01:32, Pavel Begunkov wrote: >> On 01/02/2020 01:22, Jens Axboe wrote: >>> On 1/31/20 3:15 PM, Pavel Begunkov wrote: >>>> Apart from unrelated first patch, this persues two goals: >>>> >>>> 1. start preparing io_uring to move resources handling into >>>> opcode specific functions >>>> >>>> 2. make the first step towards long-standing optimisation ideas >>>> >>>> Basically, it makes struct io_submit_state embedded into ctx, so >>>> easily accessible and persistent, and then plays a bit around that. >>> >>> Do you have any perf/latency numbers for this? Just curious if we >>> see any improvements on that front, cross submit persistence of >>> alloc caches should be a nice sync win, for example, or even >>> for peak iops by not having to replenish the pool for each batch. >>> >>> I can try and run some here too. >>> >> >> I tested the first version, but my drive is too slow, so it was only nops and >> hence no offloading. Honestly, there waren't statistically significant results. >> I'll rerun anyway. >> >> I have a plan to reuse it for a tricky optimisation, but thinking twice, I can >> just stash it until everything is done. That's not the first thing in TODO and >> will take a while. >> > > I've got numbers, but there is nothing really interesting. Throughput is > insignificantly better with the patches, but I'd need much more experiments > across reboots to confirm that. > > Let's postpone the patchset for later Sounds fine to me, no need to do it unless it's a nice cleanup, and/or provides some nice improvements. It would be great to see the splice stuff revamped, though :-) -- Jens Axboe