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=-6.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, 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 B0581C433DF for ; Fri, 31 Jul 2020 15:10:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8F5F220829 for ; Fri, 31 Jul 2020 15:10:22 +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="AAEAVeSe" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728961AbgGaPKW (ORCPT ); Fri, 31 Jul 2020 11:10:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728697AbgGaPKV (ORCPT ); Fri, 31 Jul 2020 11:10:21 -0400 Received: from mail-io1-xd44.google.com (mail-io1-xd44.google.com [IPv6:2607:f8b0:4864:20::d44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF859C061574 for ; Fri, 31 Jul 2020 08:10:21 -0700 (PDT) Received: by mail-io1-xd44.google.com with SMTP id l1so31942766ioh.5 for ; Fri, 31 Jul 2020 08:10:21 -0700 (PDT) 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=c31zs78jkbEDcaAEozn9jB01elDvx98vBlez8NhPw+w=; b=AAEAVeSeZ1ySeSQ/D4kbj7FnBIbjhRT3/zYqQOAwcxJtswLItoccGSGuHARDh7qWHX mX8qnJizZcG0woNqTMGwEQKFAj0RyhuN6vHBnsWtUjhoxAtnMqAJMNzqGEF27wjw55lR /UK0XDE5PLoD70cE0Scng0hzWA6oE4q4W4lNhlTLcDuaJY3XraExZ+kyB2n3EZ3SzCOn DNrR4MqOt9jnEmOQjU5rARL+i8r5jlhftCD5O0m507Qwwa2zuOvx4sfXfN43w7DGy+UB Ty7QM5bQbd+FVdSW5WX/XhpUqb6VVfUYYT+9XKmWwEe+Mp2S6OUBiN5jXrsH7eHMaVWw 233w== 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=c31zs78jkbEDcaAEozn9jB01elDvx98vBlez8NhPw+w=; b=Z/j9RH2fUwr2fuNxcLdt05bkmZlPGS8I8ChsST0sRo0EsieQATvOjFFgPgiJmJGpbZ XElMJ2ZzvR+FM+5rWsVo9Bgh1Tt9FiW6x2TeCiBaMTQWV8rqz+CGjje/TVK2s7m2CS7H qwc7oQWECiOqOW4Iy04hSXFZUPsRy5/ldleR1L2hxDNRnKwfP5V2XxT+8lbeqU7U2b3J EeNPyLf8VFFhAXIuZ3WPUzmifRIvlYjf33XXTMfq32E1tlbpRzaWSVsRCM8TatIprkl4 N7fwVQbcRLIJfQcOmQCzIBiNcWMcKxID5ldr1cuEe5jg3TK2U79vTyV00unrhaxAt6xa Hc7A== X-Gm-Message-State: AOAM532CyQI8tPsyUAMAHzMh6fiSFsQ36LCQzkt0yY3uIKNKAjC4iaea JdMW3Z0qq0cTJzLMhlWQGjlygFx1wGg= X-Google-Smtp-Source: ABdhPJz3kNGjJdbotqsutuQHf4kH/HX/VLK7TUtT0HmpbHEFhDMoOyq8VAXjwjwsXWC3bDViD5WiVQ== X-Received: by 2002:a6b:7610:: with SMTP id g16mr4049888iom.115.1596208220646; Fri, 31 Jul 2020 08:10:20 -0700 (PDT) Received: from [192.168.1.58] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id w15sm4905945ila.65.2020.07.31.08.10.19 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 31 Jul 2020 08:10:20 -0700 (PDT) Subject: Re: [PATCH 0/6] 5.9 small cleanups/fixes To: Pavel Begunkov , io-uring@vger.kernel.org References: <3f481017-bfc8-d0ac-fbb1-b4fbac781eb1@kernel.dk> From: Jens Axboe Message-ID: Date: Fri, 31 Jul 2020 09:10:19 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: io-uring-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 7/31/20 8:28 AM, Pavel Begunkov wrote: > On 30/07/2020 21:08, Jens Axboe wrote: >> On 7/30/20 9:43 AM, Pavel Begunkov wrote: >>> [1/1] takes apart the union, too much trouble and there is no reason >>> left for keeping it. Probably for 5.10 we can reshuffle the layout as >>> discussed. >> >> Let's hope so, because I do think this is the safest option, but it does >> incur a 5% drop for me. > > Hmm, any ideas why? If your test doesn't use neither apoll/poll/io-wq, > then it looks like either something related to slab (e.g. partial zeroing), > or magic with @task_work moved from 4th to 3rd cacheline. Was looking into it just now, but I think it was just a bad test run. Checked out and ran a new test, and then just with #1 applied which would be the only one that should impact things. And it's pretty close, so I'm going to call it a wash. So nothing to worry about I think. -- Jens Axboe