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=-5.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 D841EC433DF for ; Mon, 17 Aug 2020 10:11:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 93C392067C for ; Mon, 17 Aug 2020 10:11:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="JvW32SQt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726265AbgHQKLL (ORCPT ); Mon, 17 Aug 2020 06:11:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40958 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726151AbgHQKLH (ORCPT ); Mon, 17 Aug 2020 06:11:07 -0400 Received: from mail-lf1-x132.google.com (mail-lf1-x132.google.com [IPv6:2a00:1450:4864:20::132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 11BD2C061389 for ; Mon, 17 Aug 2020 03:11:07 -0700 (PDT) Received: by mail-lf1-x132.google.com with SMTP id j22so8078151lfm.2 for ; Mon, 17 Aug 2020 03:11:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=to:cc:references:from:autocrypt:subject:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=teNTGPBcXDcYUqCsR0LbmiwCLY1JUW3Hvwkpx9lIIw8=; b=JvW32SQtER14j1VZ/IebZrZpE4GRERB9xZBhbYWFmLaeAOcax1WhSxDIZDcYdKgwAI VLJM2mfBKxXo/WDyoXBll1UQ0L45qnTFpmfEnV+q3ePEihIc6cQcvgLaMFuhwTW1fAeS i663fimwdmOfURf5GoBrhd71uq1udddboAY61kVRinHPusRoi+Oe4QseUcvbaCDthfm9 xmYkcCoeScmbS+jKpXUkc4b9+g3UhqSA+PagYpinGr9jz6xSJuPCt4r9hx9khNGCM8gp M/wmmWSg/vNH6t5QQAU/l47mpyazvJXzOHqEP0+WZTqKXVd8HzYZ5ZNI53e015CCLbK2 rwlw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:cc:references:from:autocrypt:subject :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=teNTGPBcXDcYUqCsR0LbmiwCLY1JUW3Hvwkpx9lIIw8=; b=YfXFKyEuuwvXLgvbWI2Km2fOAneF7BAkfZUVOYmiShYHAO2zXiIVcNy2FgYGDbnpsV f1JA5e4koEyoT3wtR9fXh+YToH/meTE0IzgteTMmPEK5S3khpdxQ+t+Og6yofyB40FCj qnTwxKajLS5WWrtg9AW/pHxPlPMxnXPjJhpv+KimH6nQ99XyGLwD3/+FPHRAA3OfY3BE lcWzdmyeUXu708NBjZggkk0O0eo61CvDJlpF/evGdUF+Xci2ykmOosB7q+V5vz48XG3c 0fG9lqCBM1AWu5wN/gl0PIquJrq78ItOKF4FoAZAEwqBnuhH9c1ZwKa1TmZGMa4+FTKs wEEw== X-Gm-Message-State: AOAM532ETrXpgphfZyGRETRNdPHpjdKHwahHDTyx6NkRDuiQvvSSbFCp mBQmkzPGMjQ/+qyNHqvWFu0= X-Google-Smtp-Source: ABdhPJzNhT+DFTFdoHy3Qk2vy0P7dJBNuqQ8B1MO7OjztiHcIkglp7IZJP1KTFH7sb0NMYdm/cP10g== X-Received: by 2002:a05:6512:1055:: with SMTP id c21mr7050167lfb.84.1597659063331; Mon, 17 Aug 2020 03:11:03 -0700 (PDT) Received: from [192.168.88.252] (n146-194.tmp.edunet.ru. [213.184.146.194]) by smtp.gmail.com with ESMTPSA id 5sm5426411lfz.35.2020.08.17.03.11.02 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 17 Aug 2020 03:11:02 -0700 (PDT) To: Josef , Jens Axboe , io-uring@vger.kernel.org Cc: norman@apache.org References: <63024e23-2b71-937a-6759-17916743c16c@gmail.com> <904b4d74-09ec-0bd3-030a-59b09fb1a7da@kernel.dk> <390e6d95-040b-404e-58c4-d633d6d0041d@kernel.dk> <63b47134-ad9c-4305-3a19-8c5deb7da686@kernel.dk> <689aa6e9-bfff-3353-fc09-d8dec49485bd@kernel.dk> From: Pavel Begunkov Autocrypt: addr=asml.silence@gmail.com; prefer-encrypt=mutual; keydata= mQINBFmKBOQBEAC76ZFxLAKpDw0bKQ8CEiYJRGn8MHTUhURL02/7n1t0HkKQx2K1fCXClbps bdwSHrhOWdW61pmfMbDYbTj6ZvGRvhoLWfGkzujB2wjNcbNTXIoOzJEGISHaPf6E2IQx1ik9 6uqVkK1OMb7qRvKH0i7HYP4WJzYbEWVyLiAxUj611mC9tgd73oqZ2pLYzGTqF2j6a/obaqha +hXuWTvpDQXqcOZJXIW43atprH03G1tQs7VwR21Q1eq6Yvy2ESLdc38EqCszBfQRMmKy+cfp W3U9Mb1w0L680pXrONcnlDBCN7/sghGeMHjGKfNANjPc+0hzz3rApPxpoE7HC1uRiwC4et83 CKnncH1l7zgeBT9Oa3qEiBlaa1ZCBqrA4dY+z5fWJYjMpwI1SNp37RtF8fKXbKQg+JuUjAa9 Y6oXeyEvDHMyJYMcinl6xCqCBAXPHnHmawkMMgjr3BBRzODmMr+CPVvnYe7BFYfoajzqzq+h EyXSl3aBf0IDPTqSUrhbmjj5OEOYgRW5p+mdYtY1cXeK8copmd+fd/eTkghok5li58AojCba jRjp7zVOLOjDlpxxiKhuFmpV4yWNh5JJaTbwCRSd04sCcDNlJj+TehTr+o1QiORzc2t+N5iJ NbILft19Izdn8U39T5oWiynqa1qCLgbuFtnYx1HlUq/HvAm+kwARAQABtDFQYXZlbCBCZWd1 bmtvdiAoc2lsZW5jZSkgPGFzbWwuc2lsZW5jZUBnbWFpbC5jb20+iQJOBBMBCAA4FiEE+6Ju PTjTbx479o3OWt5b1Glr+6UFAlmKBOQCGwMFCwkIBwIGFQgJCgsCBBYCAwECHgECF4AACgkQ Wt5b1Glr+6WxZA//QueaKHzgdnOikJ7NA/Vq8FmhRlwgtP0+E+w93kL+ZGLzS/cUCIjn2f4Q Mcutj2Neg0CcYPX3b2nJiKr5Vn0rjJ/suiaOa1h1KzyNTOmxnsqE5fmxOf6C6x+NKE18I5Jy xzLQoktbdDVA7JfB1itt6iWSNoOTVcvFyvfe5ggy6FSCcP+m1RlR58XxVLH+qlAvxxOeEr/e aQfUzrs7gqdSd9zQGEZo0jtuBiB7k98t9y0oC9Jz0PJdvaj1NZUgtXG9pEtww3LdeXP/TkFl HBSxVflzeoFaj4UAuy8+uve7ya/ECNCc8kk0VYaEjoVrzJcYdKP583iRhOLlZA6HEmn/+Gh9 4orG67HNiJlbFiW3whxGizWsrtFNLsSP1YrEReYk9j1SoUHHzsu+ZtNfKuHIhK0sU07G1OPN 2rDLlzUWR9Jc22INAkhVHOogOcc5ajMGhgWcBJMLCoi219HlX69LIDu3Y34uIg9QPZIC2jwr 24W0kxmK6avJr7+n4o8m6sOJvhlumSp5TSNhRiKvAHB1I2JB8Q1yZCIPzx+w1ALxuoWiCdwV M/azguU42R17IuBzK0S3hPjXpEi2sK/k4pEPnHVUv9Cu09HCNnd6BRfFGjo8M9kZvw360gC1 reeMdqGjwQ68o9x0R7NBRrtUOh48TDLXCANAg97wjPoy37dQE7e5Ag0EWYoE5AEQAMWS+aBV IJtCjwtfCOV98NamFpDEjBMrCAfLm7wZlmXy5I6o7nzzCxEw06P2rhzp1hIqkaab1kHySU7g dkpjmQ7Jjlrf6KdMP87mC/Hx4+zgVCkTQCKkIxNE76Ff3O9uTvkWCspSh9J0qPYyCaVta2D1 Sq5HZ8WFcap71iVO1f2/FEHKJNz/YTSOS/W7dxJdXl2eoj3gYX2UZNfoaVv8OXKaWslZlgqN jSg9wsTv1K73AnQKt4fFhscN9YFxhtgD/SQuOldE5Ws4UlJoaFX/yCoJL3ky2kC0WFngzwRF Yo6u/KON/o28yyP+alYRMBrN0Dm60FuVSIFafSqXoJTIjSZ6olbEoT0u17Rag8BxnxryMrgR dkccq272MaSS0eOC9K2rtvxzddohRFPcy/8bkX+t2iukTDz75KSTKO+chce62Xxdg62dpkZX xK+HeDCZ7gRNZvAbDETr6XI63hPKi891GeZqvqQVYR8e+V2725w+H1iv3THiB1tx4L2bXZDI DtMKQ5D2RvCHNdPNcZeldEoJwKoA60yg6tuUquvsLvfCwtrmVI2rL2djYxRfGNmFMrUDN1Xq F3xozA91q3iZd9OYi9G+M/OA01husBdcIzj1hu0aL+MGg4Gqk6XwjoSxVd4YT41kTU7Kk+/I 5/Nf+i88ULt6HanBYcY/+Daeo/XFABEBAAGJAjYEGAEIACAWIQT7om49ONNvHjv2jc5a3lvU aWv7pQUCWYoE5AIbDAAKCRBa3lvUaWv7pfmcEACKTRQ28b1y5ztKuLdLr79+T+LwZKHjX++P 4wKjEOECCcB6KCv3hP+J2GCXDOPZvdg/ZYZafqP68Yy8AZqkfa4qPYHmIdpODtRzZSL48kM8 LRzV8Rl7J3ItvzdBRxf4T/Zseu5U6ELiQdCUkPGsJcPIJkgPjO2ROG/ZtYa9DvnShNWPlp+R uPwPccEQPWO/NP4fJl2zwC6byjljZhW5kxYswGMLBwb5cDUZAisIukyAa8Xshdan6C2RZcNs rB3L7vsg/R8UCehxOH0C+NypG2GqjVejNZsc7bgV49EOVltS+GmGyY+moIzxsuLmT93rqyII 5rSbbcTLe6KBYcs24XEoo49Zm9oDA3jYvNpeYD8rDcnNbuZh9kTgBwFN41JHOPv0W2FEEWqe JsCwQdcOQ56rtezdCJUYmRAt3BsfjN3Jn3N6rpodi4Dkdli8HylM5iq4ooeb5VkQ7UZxbCWt UVMKkOCdFhutRmYp0mbv2e87IK4erwNHQRkHUkzbsuym8RVpAZbLzLPIYK/J3RTErL6Z99N2 m3J6pjwSJY/zNwuFPs9zGEnRO4g0BUbwGdbuvDzaq6/3OJLKohr5eLXNU3JkT+3HezydWm3W OPhauth7W0db74Qd49HXK0xe/aPrK+Cp+kU1HRactyNtF8jZQbhMCC8vMGukZtWaAwpjWiiH bA== Subject: Re: io_uring process termination/killing is not working Message-ID: Date: Mon, 17 Aug 2020 13:08:56 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.0 MIME-Version: 1.0 In-Reply-To: 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 17/08/2020 11:58, Josef wrote: >> BTW, something I think you're aware of, but wanted to bring up >> explicitly - if IORING_FEAT_FAST_POLL is available in the ring features, >> then you generally don't want/need to link potentially blocking requests >> on pollable files with a poll in front. io_uring will do this >> internally, and save you an sqe and completion event for each of these >> types of requests. >> >> Your test case is a perfect example of that, neither the accept nor the >> socket read would need a poll linked in front of them, as they are both >> pollable file types and will not trigger use of an async thread to wait >> for the event. Instead an internal poll is armed which will trigger the >> issue of that request, when the socket is ready > > I am guessing if the socket(non blocking) is not writable as you said > it's a pollable file type, io_uring will first use an internal poll to > check if the socket is writable, right? so I don't explicitly need a > poll(POLLOUT) IIRC, it won't. E.g. one possible scenario: 1. io_issue_sqe(force_nonblock=true), aka inlined execution 2. io_send() sets REQ_F_NOWAIT 3. __io_queue_sqe() fails such request. BTW, Jens, it's not really clear to me, what semantics is expected from io_uring when *NOWAIT is set (e.g. MSG_DONTWAIT)? If that's fail-fast, then it doesn't look consistent that io_wq_submit_work() keeps resubmitting it in a loop. -- Pavel Begunkov