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=-5.5 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 1B5F5C433DF for ; Sun, 12 Jul 2020 15:59:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E3CF9206B6 for ; Sun, 12 Jul 2020 15:59:11 +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="qx+VmWns" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728859AbgGLP7L (ORCPT ); Sun, 12 Jul 2020 11:59:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46760 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728854AbgGLP7L (ORCPT ); Sun, 12 Jul 2020 11:59:11 -0400 Received: from mail-pf1-x431.google.com (mail-pf1-x431.google.com [IPv6:2607:f8b0:4864:20::431]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0310AC061794 for ; Sun, 12 Jul 2020 08:59:10 -0700 (PDT) Received: by mail-pf1-x431.google.com with SMTP id u5so4883312pfn.7 for ; Sun, 12 Jul 2020 08:59:10 -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=rCUr70PBm03rm1kcL7BHJsBV86MBxPVl+9xm7KFkHkM=; b=qx+VmWnsK36uyPoS6Z2EfVBqtWUjc99g8p3/LO7fVMNghcamb4OOPAkv5H8sRw+Y+a UjyzFhOvAGfuYm7pY6n5VJvQ33RHf84jO8nEUI81F1Md1CBW+Ag85eHPv0qBYdBMXNMg Mp7ZLpcKeFu2t+HVs+kz6aihC39H4ZA708/MVgpoflX1Siisxckagl3WgtzSSoD/Kklu ui6n6jtmMtwuXHswvejY0BNGl4BzCHXjd+ZFyEPkH98qUpHSuMnvrCYLUDXXSNxbjDwu FCVImmifQwWJHGtNwrdQwKcFwio5GdviSwG4Ob6tgAJbLSGX3QumwcEswN4p0fZ9FRuP OuIg== 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=rCUr70PBm03rm1kcL7BHJsBV86MBxPVl+9xm7KFkHkM=; b=C33J4k4G/i8qVMBFVudI8qSeqC/BcdQXFqt4+YhkUbQdqN0wCb4hBqU3vGtWfjoR5I tfckvUDwSwYYX7R0a64DqXvynJaiZ0+D6sqln6hHQPJhANE8CScozJ5Bjo9PNO8jVuX5 KuGPbrEO4SoaXSo98v2Q82cYoEKaWEB9OGOi6crVAyoD3rCvZ8zjoHqSGIw0AX/JHLRb IQ5qCpCMAJ47/npYp6xLLvzlNoeD1/GAbFpmGjfa0HnYUspIK7MUQJOhtDtOs0/4qNnK 8s46pJKHB+1A0yICUyd3bFhtEVFh2E/4qiW4CGKdqOkgSExnQJZwLyQnCohPcizAKJQI h90A== X-Gm-Message-State: AOAM532gPzKHQScgjzokxpVkIQ2yRQlSSiV8V8xR3cMzKjnVFRnH8dhL +TlDqPbdP2lzgvkzogjZ+HBpywZgbA4IVg== X-Google-Smtp-Source: ABdhPJy0wAXhBDQUxaDc89bDoaTn+gAoHPz5PDTKBXvKdMCcXK1Dv6UXTmiaVAR5pbMctycsgyYTGQ== X-Received: by 2002:a63:5004:: with SMTP id e4mr43952786pgb.208.1594569549811; Sun, 12 Jul 2020 08:59:09 -0700 (PDT) Received: from [192.168.1.182] ([66.219.217.173]) by smtp.gmail.com with ESMTPSA id e5sm11518170pjy.26.2020.07.12.08.59.09 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 12 Jul 2020 08:59:09 -0700 (PDT) Subject: Re: [RFC 0/9] scrap 24 bytes from io_kiocb To: Pavel Begunkov , io-uring@vger.kernel.org References: From: Jens Axboe Message-ID: Date: Sun, 12 Jul 2020 09:59:08 -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 7/12/20 3:41 AM, Pavel Begunkov wrote: > Make io_kiocb slimmer by 24 bytes mainly by revising lists usage. The > drawback is adding extra kmalloc in draining path, but that's a slow > path, so meh. It also frees some space for the deferred completion path > if would be needed in the future, but the main idea here is to shrink it > to 3 cachelines in the end. > > I'm not happy yet with a few details, so that's not final, but it would > be lovely to hear some feedback. I think it looks pretty good, most of the changes are straight forward. Adding a completion entry that shares the submit space is a good idea, and really helps bring it together. >From a quick look, the only part I'm not super crazy about is patch #3. I'd probably rather use a generic list name and not unionize the tw lists. -- Jens Axboe