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=-5.3 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 28BABC47096 for ; Sun, 6 Jun 2021 14:08:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 043D561420 for ; Sun, 6 Jun 2021 14:08:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230025AbhFFOKH (ORCPT ); Sun, 6 Jun 2021 10:10:07 -0400 Received: from out30-43.freemail.mail.aliyun.com ([115.124.30.43]:38990 "EHLO out30-43.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230003AbhFFOKG (ORCPT ); Sun, 6 Jun 2021 10:10:06 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R871e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04420;MF=haoxu@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0UbSrMv5_1622988495; Received: from B-25KNML85-0107.local(mailfrom:haoxu@linux.alibaba.com fp:SMTPD_---0UbSrMv5_1622988495) by smtp.aliyun-inc.com(127.0.0.1); Sun, 06 Jun 2021 22:08:15 +0800 Subject: Re: Question about poll_multi_file To: Jens Axboe , Pavel Begunkov Cc: io-uring , Joseph Qi References: From: Hao Xu Message-ID: <4c341c96-8d66-eae3-ba4a-e1655ee463a8@linux.alibaba.com> Date: Sun, 6 Jun 2021 22:08:14 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 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 2021/6/4 上午2:01, Jens Axboe 写道: > On 6/3/21 6:53 AM, Hao Xu wrote: >> Hi Jens, >> I've a question about poll_multi_file in io_do_iopoll(). >> It keeps spinning in f_op->iopoll() if poll_multi_file is >> true (and we're under the requested amount). But in my >> understanding, reqs may be in different hardware queues >> for blk-mq device even in this situation. >> Should we consider the hardware queue number as well? Some >> thing like below: > > That looks reasonable to me - do you have any performance > numbers to go with it? Not very easy for me to construct a good case. I'm trying to mock the below situation: manully control uring reqs to go to 2 hardware queues, like: hw_queue0 hw_queue1 heavy_req simple_req heavy_req simple_req ... ... heavy_req is some request that needs more time to complete, while simple_req takes less time. And make the io_do_iopoll() alway first spin on hw_queue0. any ideas? Thanks, Hao >