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=-4.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 ED008C433C1 for ; Wed, 24 Mar 2021 02:15:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B9776619E5 for ; Wed, 24 Mar 2021 02:15:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231284AbhCXCOk (ORCPT ); Tue, 23 Mar 2021 22:14:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60278 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234788AbhCXCOX (ORCPT ); Tue, 23 Mar 2021 22:14:23 -0400 Received: from mail-pf1-x436.google.com (mail-pf1-x436.google.com [IPv6:2607:f8b0:4864:20::436]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC91DC061763 for ; Tue, 23 Mar 2021 19:14:22 -0700 (PDT) Received: by mail-pf1-x436.google.com with SMTP id x126so16233769pfc.13 for ; Tue, 23 Mar 2021 19:14:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=L5VATD+SgSvP0uDDMv0XEmMh9UsDKLQL6ZxPV2i7Yxw=; b=EbIbrB3jhU2ezolVNh038d93wXGIPGQlWRfFzJtv3R7zlPJdVHGDPnpgAjpK1CUFTV GN0BMr+Ls8uCBrL168IF4TOtYziKqCs/Rl0v2ADkD4hu2vEEQbV4XQV1B3vbfy4UwiuS SIyrembSTHx8vy+bHVbUDjAyZy5QYUuU3gVtAw4uPnWpChDK4S/moJj/WIRmHbaG5xWJ /J9rByvniMcAulkWI4zEMT0S7cT+k80232Dzy3SSjrkWy+8/dvMRyZ5BX8kVk/jCp/2n RiSpfhJD2UTtf+GZVzABgr/Lw4p/+Unx1JRsi1cn6D7U9m0WgGwKjDBW6OFLmFZA39kb iXdQ== 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=L5VATD+SgSvP0uDDMv0XEmMh9UsDKLQL6ZxPV2i7Yxw=; b=bSZijcoEq/GCC3avYuaZuq+K/kfDY2wGxZsumL59ZNpeI8ZgJwL6YSbyuifRNRQmJ9 10jx47NL1Lds9rK2fXpcCIvwj234+euJ5DdDbEgnsnzki0zDgIPupFi5ezs3puGhqKdc Gqb4yQzWZfJOWREf0mScin+mOK3nXe8V4tVTISIi15049yrIjctwDC2y6DEPKFa5hzUE lWRLjSyUGvazk5UmxWAtQeErSzM+kjL/E5fw1beKxW1m30dXdBiTTEAp2LFiKfmQztg2 ieYa9a0TvLN+ji6RVgYzZZk9sEKfK6fl6ynU/SexMYqqFAneDvjQ8Eqyx5qGvEEXvqNO //xA== X-Gm-Message-State: AOAM531rAzhPt+l+bpvIE2idZjNyo38+KyxipJF1/795mEXhOOhPdWoK 3cqg4uDsTxEtUf7xrWZBbtFsS6KflqY= X-Google-Smtp-Source: ABdhPJzQ3MpLwZgTV9MzaxYNulsP4JQQX6g+Wo5jJcSRpREb2UzwbmT2r1ThtR0FNHZ4y0EsbIQ5qg== X-Received: by 2002:a63:de53:: with SMTP id y19mr1019050pgi.191.1616552062571; Tue, 23 Mar 2021 19:14:22 -0700 (PDT) Received: from B-D1K7ML85-0059.local ([47.89.83.92]) by smtp.gmail.com with ESMTPSA id d2sm404214pjx.42.2021.03.23.19.14.20 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 23 Mar 2021 19:14:22 -0700 (PDT) Subject: Re: [ANNOUNCEMENT] io_uring SQPOLL sharing changes To: Jens Axboe , 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> <7a6899a6-ece8-f2f8-3fbc-3adfcbf942b2@kernel.dk> From: Joseph Qi Message-ID: <67d886e8-12ee-0b4c-25a7-a8cf687c2e49@gmail.com> Date: Wed, 24 Mar 2021 10:14:15 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <7a6899a6-ece8-f2f8-3fbc-3adfcbf942b2@kernel.dk> 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 3/24/21 12:22 AM, Jens Axboe wrote: > 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? > Yes, we'll do it later. Thanks, Joseph