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=-7.4 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 0311BC388F9 for ; Tue, 27 Oct 2020 13:35:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B21A421707 for ; Tue, 27 Oct 2020 13:35:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752295AbgJ0Nfs (ORCPT ); Tue, 27 Oct 2020 09:35:48 -0400 Received: from out30-130.freemail.mail.aliyun.com ([115.124.30.130]:53614 "EHLO out30-130.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752282AbgJ0Nfs (ORCPT ); Tue, 27 Oct 2020 09:35:48 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R191e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=alimailimapcm10staff010182156082;MF=xiaoguang.wang@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0UDNENH4_1603805745; Received: from 30.225.32.190(mailfrom:xiaoguang.wang@linux.alibaba.com fp:SMTPD_---0UDNENH4_1603805745) by smtp.aliyun-inc.com(127.0.0.1); Tue, 27 Oct 2020 21:35:45 +0800 Subject: Re: [PATCH 0/2] improve SQPOLL handling To: io-uring@vger.kernel.org Cc: axboe@kernel.dk, asml.silence@gmail.com, joseph.qi@linux.alibaba.com References: <20201020082345.19628-1-xiaoguang.wang@linux.alibaba.com> From: Xiaoguang Wang Message-ID: <9b0ee22a-1dc3-932e-d2a7-360ff463e04d@linux.alibaba.com> Date: Tue, 27 Oct 2020 21:34:43 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.1 MIME-Version: 1.0 In-Reply-To: <20201020082345.19628-1-xiaoguang.wang@linux.alibaba.com> Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org hello, This is a gentle ping. Regards, Xiaogaung Wang > The first patch tries to improve various issues in current implementation: > The prepare_to_wait() usage in __io_sq_thread() is weird. If multiple ctxs > share one same poll thread, one ctx will put poll thread in TASK_INTERRUPTIBLE, > but if other ctxs have work to do, we don't need to change task's stat at all. > I think only if all ctxs don't have work to do, we can do it. > We use round-robin strategy to make multiple ctxs share one same poll thread, > but there are various condition in __io_sq_thread(), which seems complicated and > may affect round-robin strategy. > In io_sq_thread(), we always call io_sq_thread_drop_mm() when we complete a > round of ctxs iteration, which maybe inefficient. > > The second patch adds a IORING_SETUP_SQPOLL_PERCPU flag, for those rings which > have SQPOLL enabled and are willing to be bound to one same cpu, hence share > one same poll thread, add a capability that these rings can share one poll thread > by specifying a new IORING_SETUP_SQPOLL_PERCPU flag. FIO tool can integrate this > feature easily, so we can test multiple rings to share same poll thread easily. > > Xiaoguang Wang (2): > io_uring: refactor io_sq_thread() handling > io_uring: support multiple rings to share same poll thread by > specifying same cpu > > fs/io_uring.c | 307 ++++++++++++++++++++-------------- > include/uapi/linux/io_uring.h | 1 + > 2 files changed, 181 insertions(+), 127 deletions(-) >