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, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,UNPARSEABLE_RELAY,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 E7ABEC4338F for ; Wed, 28 Jul 2021 06:06:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CBDC960F46 for ; Wed, 28 Jul 2021 06:06:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233082AbhG1GGN (ORCPT ); Wed, 28 Jul 2021 02:06:13 -0400 Received: from out30-44.freemail.mail.aliyun.com ([115.124.30.44]:49608 "EHLO out30-44.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233574AbhG1GGN (ORCPT ); Wed, 28 Jul 2021 02:06:13 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R101e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04426;MF=haoxu@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0UhDmBEo_1627452370; Received: from B-25KNML85-0107.local(mailfrom:haoxu@linux.alibaba.com fp:SMTPD_---0UhDmBEo_1627452370) by smtp.aliyun-inc.com(127.0.0.1); Wed, 28 Jul 2021 14:06:10 +0800 Subject: Re: [PATCH io_uring-5.14 v2] io_uring: remove double poll wait entry for pure poll To: Jens Axboe , Pavel Begunkov Cc: io-uring@vger.kernel.org, Joseph Qi References: <20210723092227.137526-1-haoxu@linux.alibaba.com> <824dcbe0-34da-a075-12eb-ce7529f3e3f7@linux.alibaba.com> <28ce8b3d-e9d2-2fed-e73c-fb09913eea78@gmail.com> <85703a7e-40cd-1f80-9ca4-9c0a2f665e45@kernel.dk> From: Hao Xu Message-ID: Date: Wed, 28 Jul 2021 14:06:10 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.10.2 MIME-Version: 1.0 In-Reply-To: <85703a7e-40cd-1f80-9ca4-9c0a2f665e45@kernel.dk> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org 在 2021/7/28 上午6:46, Jens Axboe 写道: > On 7/26/21 8:39 AM, Hao Xu wrote: >> 在 2021/7/26 下午8:40, Pavel Begunkov 写道: >>> On 7/24/21 5:48 AM, Hao Xu wrote: >>>> 在 2021/7/23 下午10:31, Pavel Begunkov 写道: >>>>> On 7/23/21 10:22 AM, Hao Xu wrote: >>>>>> For pure poll requests, we should remove the double poll wait entry. >>>>>> And io_poll_remove_double() is good enough for it compared with >>>>>> io_poll_remove_waitqs(). >>>>> >>>>> 5.14 in the subject hints me that it's a fix. Is it? >>>>> Can you add what it fixes or expand on why it's better? >>>> Hi Pavel, I found that for poll_add() requests, it doesn't remove the >>>> double poll wait entry when it's done, neither after vfs_poll() or in >>>> the poll completion handler. The patch is mainly to fix it. >>> >>> Ok, sounds good. Please resend with updated description, and >>> let's add some tags. >>> >>> Fixes: 88e41cf928a6 ("io_uring: add multishot mode for IORING_OP_POLL_ADD") >>> Cc: stable@vger.kernel.org # 5.13+ >>> >>> Also, I'd prefer the commit title to make more clear that it's a >>> fix. E.g. "io_uring: fix poll requests leaking second poll entries". >>> >>> Btw, seems it should fix hangs in ./poll-mshot-update >> Sure，I'll send v3 soon, sorry for my unprofessionalism.. > > Are you going to send out v3? > v3 sent. Btw I'm working on letting fast poll support multishot, I believe that will benefit non-persistent programming, let's see if it helps accept().