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 72DF9C352A3 for ; Fri, 14 Feb 2020 02:45:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4167820848 for ; Fri, 14 Feb 2020 02:45:46 +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="k3lqcizh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728053AbgBNCpp (ORCPT ); Thu, 13 Feb 2020 21:45:45 -0500 Received: from mail-pl1-f172.google.com ([209.85.214.172]:44534 "EHLO mail-pl1-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728052AbgBNCpp (ORCPT ); Thu, 13 Feb 2020 21:45:45 -0500 Received: by mail-pl1-f172.google.com with SMTP id d9so3134076plo.11 for ; Thu, 13 Feb 2020 18:45:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=Ua/Oe4PqD4ZOnM+trG6adp+/P5Pkukias5LDOYLjiyY=; b=k3lqcizhQpXjxHhUhBv8lvsexolRsm28jNHO+n9BjcQApprlBg/iInRdBmkrryDpyu ilrd3mFDXCfWyqZtXqpn5P4wkHjkRsbsL81SvWROwparyXNiD12C2eCq40z/+NnFYf10 f+8QPX21JdgOdIfRqW0qN+WZE146SSTV5HLl2iRCV6NLY9EAwzld9Cdg4fxWFq4buNah MrpiWRB/UM0PaWFvwvqXZyK01YUshGG/y3WYGIsCFMFYwzWLey7Yy/OYowsbuAN8B/WA LaXDbAWrojLMwCgRlZxCpiCEg3PI3Ww8P1TvxG7KeqoCFbgkFGjKmqF++FNHDQD7ExYT lRiA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=Ua/Oe4PqD4ZOnM+trG6adp+/P5Pkukias5LDOYLjiyY=; b=BA7XZFzapj9/8yqxwlsHRq2v007fISR+gNGgE5Ms9V4zQ6UXeWcx+JQj0E1VlWkSwg ap4mYaQkyEVZxo6LAjyW0Ox1UpNSm579PwBV0SPPtIjAMlsqmsXBR0rBZSI+sVX3JPuK Jg5l8ovjm90niMIoxi+nx+vy20tDQ7HlnzCCOD5C00BQLZbChrWv0mg3NNs+dRG2d36l lZ53Q3WjHC+LwFcK0epJDVmkOj1ydXVoDRhb4l7envg0W9aAuKSb/nGbF5DeGTwavj4m Z5t3lcAqk4qAxH5zCpZw9+ZUbdnrfuL94AI8Ttda10c20XBigEcewozfuvs2KR2I9Usn kZGA== X-Gm-Message-State: APjAAAVw8215im5vUeOt95mMMMfdxV71OgdlK3HT6D1ZpuE2isYDCHbw J4N04uBoehwNGPhop4lLNCojGi4HOzw= X-Google-Smtp-Source: APXvYqwx7L26L6OjysHLyfP3SrhviU7g6UaMBSHHqyVkxYBWA+b2CqPYHUjud5ZVIB+IYIbKGYfAWw== X-Received: by 2002:a17:902:7d8c:: with SMTP id a12mr1048190plm.47.1581648344625; Thu, 13 Feb 2020 18:45:44 -0800 (PST) Received: from [192.168.1.188] ([66.219.217.145]) by smtp.gmail.com with ESMTPSA id l69sm4663298pgd.1.2020.02.13.18.45.43 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 13 Feb 2020 18:45:43 -0800 (PST) Subject: Re: [ISSUE] The time cost of IOSQE_IO_LINK To: =?UTF-8?B?Q2FydGVyIExpIOadjumAmua0sg==?= Cc: Pavel Begunkov , io-uring References: <9FEF0D34-A012-4505-AA4E-FF97CC302A33@eoitek.com> <8a3ee653-77ed-105d-c1c3-87087451914e@kernel.dk> <9a8e4c8a-f8b2-900d-92b6-cc69b6adf324@gmail.com> <5f09d89a-0c6d-47c2-465c-993af0c7ae71@kernel.dk> <7E66D70C-BE4E-4236-A49B-9843F66EA322@eoitek.com> <671A3FE3-FA12-43D8-ADF0-D1DB463B053F@eoitek.com> From: Jens Axboe Message-ID: <217eda7b-3742-a50b-7d6a-c1294a85c8e0@kernel.dk> Date: Thu, 13 Feb 2020 19:45:42 -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: <671A3FE3-FA12-43D8-ADF0-D1DB463B053F@eoitek.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: io-uring-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 2/13/20 6:25 PM, Carter Li 李通洲 wrote: > Another suggestion: we should always try completing operations inline > unless IOSQE_ASYNC is specified, no matter if the operations are preceded > by a poll. Yes that's a given, the problem is that the poll completion is run inside the waitqueue handler, and with that locked and interrupts disabled. So it's not quite that easy, unfortunately. -- Jens Axboe