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,DKIM_SIGNED, DKIM_VALID,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 2938BC433DB for ; Tue, 23 Mar 2021 16:23:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ED4A5619BA for ; Tue, 23 Mar 2021 16:23:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233030AbhCWQXH (ORCPT ); Tue, 23 Mar 2021 12:23:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45422 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233313AbhCWQWu (ORCPT ); Tue, 23 Mar 2021 12:22:50 -0400 Received: from mail-io1-xd2a.google.com (mail-io1-xd2a.google.com [IPv6:2607:f8b0:4864:20::d2a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 17358C061574 for ; Tue, 23 Mar 2021 09:22:50 -0700 (PDT) Received: by mail-io1-xd2a.google.com with SMTP id v26so18301301iox.11 for ; Tue, 23 Mar 2021 09:22:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=E65N5dBdSastfupDoinU7CjcbcUwOs5GyrIfbgPRrxM=; b=GRrvuN20P4ql2GQRaGQREd/JeAzkv62PndfuFflouWqRrS3vPMSOWp/5qSHRcAbDPT VDysJznf4apQWcGRxpkTp7dnOQfs7AiaYUYIVO/8BGLh+keeSiyQILqcFU0dqf19KLvc u0XcimcWscUnoKqcGW2pmB/oMhafueVB2j4ZGWJYMFhFHEIrdYmqFYpvJ+bbs90kgsVA VUNG5gnkXf2s7uO/p3tT9w9lJcLyzxRxRp030ABJgSviaX+c0cVxsolkhPH0HVlgk4mw 24S5GtSN7lLox11TyjkhblFmt79VOJLiXBB5byBhJfGGrxjpOayluyo8VTBViT4BUEOU AZnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=E65N5dBdSastfupDoinU7CjcbcUwOs5GyrIfbgPRrxM=; b=mx16uMcc+OyxtopTV/sPHjBzgOhZ78VTxx/mYHlLpZpnLe5pVp+wBimGMmwlCnStY6 gZobhjper7IKa3Gp+kvXqVd/jicWdZnueI/6WdtHqbOVoGILfFXX7HZltahXnuL0SjWU 44vPcay4vDgErmJySwOZdxSEd27VSsy+RJrvi3OrbTUanYHLZr/kXIidHjW+2OwykYb1 m+AkUb/lOwAD8tvhOUDwkAGqvcgJPSdjcAUmpZccv7Cl3EemCeMrzVICfDmrzK4++sAg qn1a9Q4X9sNT2sei/YBsas7O1JUInd8kdtrREuGNdz2cdy1JBC5rL1GsFFu+Ess1c4bO nFTg== X-Gm-Message-State: AOAM530Ja8pvs7C7IkKE3VPMXS/35fnM9eBFK7coRME/fRrB/NqCYJMt x+s6oXe8p4o35A9FTo5h0h+dWbw8Xbf27g== X-Google-Smtp-Source: ABdhPJyGuegDHCUeS7bUX096u8uRgvfHfr2uZd05oLG5RNmTQ0eLUWJqYeoJBZ3j+4F1+7hY8oRXOQ== X-Received: by 2002:a05:6638:224e:: with SMTP id m14mr5400711jas.8.1616516569499; Tue, 23 Mar 2021 09:22:49 -0700 (PDT) Received: from [192.168.1.30] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id 13sm9515643ioz.40.2021.03.23.09.22.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 23 Mar 2021 09:22:49 -0700 (PDT) Subject: Re: [ANNOUNCEMENT] io_uring SQPOLL sharing changes To: Joseph Qi , Xiaoguang Wang , Pavel Begunkov , io-uring , Hao Xu References: <30563957-709a-73a2-7d54-58419089d61a@linux.alibaba.com> <1afd5237-4363-9178-917e-3132ba1b89c3@kernel.dk> <293e88d8-7fa5-edf4-226c-1e42dec9af67@linux.alibaba.com> From: Jens Axboe Message-ID: <7a6899a6-ece8-f2f8-3fbc-3adfcbf942b2@kernel.dk> Date: Tue, 23 Mar 2021 10:22:48 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <293e88d8-7fa5-edf4-226c-1e42dec9af67@linux.alibaba.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 3/22/21 10:09 PM, Joseph Qi wrote: > > > On 3/22/21 10:49 PM, Jens Axboe wrote: >> On 3/21/21 11:54 PM, Xiaoguang Wang wrote: >>> hi Pavel, >>> >>>> Hey, >>>> >>>> You may have already noticed, but there will be a change how SQPOLL >>>> is shared in 5.12. In particular, SQPOLL may be shared only by processes >>>> belonging to the same thread group. If this condition is not fulfilled, >>>> then it silently creates a new SQPOLL task. >>> >>> Thanks for your kindly reminder, currently we only share sqpoll thread >>> in threads belonging to one same process. >> >> That's good to know, imho it is also the only thing that _really_ makes >> sense to do. >> >> Since we're on the topic, are you actively using the percpu thread setup >> that you sent out patches for earlier? That could still work within >> the new scheme of having io threads, but I'd be curious to know first >> if you guys are actually using it. >> > > Yes, we've already used percpu sqthread feature in our production > environment, in which 16 application threads share the same sqthread, > and it gains ~20% rt improvement compared with libaio. Great! Any chance I can get you to re-post the patches against the current tree? -- Jens Axboe