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=-7.2 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 6FA88C4338F for ; Tue, 17 Aug 2021 12:08:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4F7F561029 for ; Tue, 17 Aug 2021 12:08:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236902AbhHQMJJ (ORCPT ); Tue, 17 Aug 2021 08:09:09 -0400 Received: from out30-132.freemail.mail.aliyun.com ([115.124.30.132]:47149 "EHLO out30-132.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237085AbhHQMJI (ORCPT ); Tue, 17 Aug 2021 08:09:08 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R671e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04394;MF=haoxu@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0UjPoDao_1629202113; Received: from B-25KNML85-0107.local(mailfrom:haoxu@linux.alibaba.com fp:SMTPD_---0UjPoDao_1629202113) by smtp.aliyun-inc.com(127.0.0.1); Tue, 17 Aug 2021 20:08:33 +0800 Subject: Re: [PATCH] io_uring: consider cgroup setting when binding sqpoll cpu To: Jens Axboe Cc: io-uring@vger.kernel.org, Pavel Begunkov , Joseph Qi References: <20210815151049.182340-1-haoxu@linux.alibaba.com> <9d0a001a-bdab-9399-d8c3-19191785d3c7@kernel.dk> <0c3195be-7109-861f-ff05-a4f804380e1c@linux.alibaba.com> From: Hao Xu Message-ID: <2d7ac2b1-0f64-93ff-fbb1-e5db9b92fd2d@linux.alibaba.com> Date: Tue, 17 Aug 2021 20:08:33 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: 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 2021/8/17 上午12:58, Jens Axboe 写道: > On 8/16/21 12:04 AM, Hao Xu wrote: >> 在 2021/8/15 下午11:19, Jens Axboe 写道: >>> On 8/15/21 9:10 AM, Hao Xu wrote: >>>> Since sqthread is userspace like thread now, it should respect cgroup >>>> setting, thus we should consider current allowed cpuset when doing >>>> cpu binding for sqthread. >>> >>> This seems a bit convoluted for what it needs to do. Surely we can just >>> test sqd->sq_cpu directly in the task_cs()? >> I didn't know task_cs() before, it seems to be a static function, which >> is called by cpuset_cpus_allowed(), and this one is exposed. > > But it'd be a much saner to add a helper for this rather than add all > of that boiler plate code to io_uring just to check for whether or not > a CPU is set in a mask. I looked into cpuset_cpus_allowed(), it seems the code logic guarantee_online_cpus() is neccessary? It guarantees the cpumask returned are all online cpus. >