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 20237C4361B for ; Thu, 17 Dec 2020 16:56:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E1A13233A2 for ; Thu, 17 Dec 2020 16:56:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728160AbgLQQzy (ORCPT ); Thu, 17 Dec 2020 11:55:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726291AbgLQQzu (ORCPT ); Thu, 17 Dec 2020 11:55:50 -0500 Received: from mail-io1-xd35.google.com (mail-io1-xd35.google.com [IPv6:2607:f8b0:4864:20::d35]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9BBB2C0617B0 for ; Thu, 17 Dec 2020 08:55:10 -0800 (PST) Received: by mail-io1-xd35.google.com with SMTP id y5so28129973iow.5 for ; Thu, 17 Dec 2020 08:55:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=94SXVPLk6dxrjkrztJ2xCBJHw01MzQaAZHGiXBHQxjw=; b=laaH/9a3BSonuTozLMpmsGNGND4KidMRwkNzS66B7kd4gHmdkITBRmJywWMFV+DyZS 4kleven7BErPsD/N9yfbvbrbeVvP3ZFqGslY8vButHdNseA4He9bnBL66MHZPxJ3MVSs W7LJOwHsITLQMqKF4wlk2rKjVIOVAR5ujs9rdC2I/PaDhluhXwCrRg/fg/dsMB4fWry/ pkz03QujcK/ZxvQ348BtRfOkDGfG0ZsAjO7cFBH0s8hPUhx2dYC1P3jaUoMAl1MstjMQ HqA4M3/FMKOaUdmizLqcX7s5RZvESIS95KS05s02On47YG9tl45tuuN8v4uY2opicYEB c4lA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=94SXVPLk6dxrjkrztJ2xCBJHw01MzQaAZHGiXBHQxjw=; b=bLEu5nUY+1FnIeBr1GDRJjfJCdjPwpo9VLTR3fmosvIc9cikoj11MLven9Jb/xEmCs CQVvaatWAXeHI/7Qo5ptKV1Zej6JDsEtEeHRiFrI6t1Xypbf8hrWVHPQj3wXD6G0tegn m7dYB1R7vVEVTq8ek52czZ0W/BSIM+KLJvW3cvRHLIidl41V9YSVtkWsfbHUhanlgSkr SB4Vcm4zPU8PVIAPFdeRwErLxtMO+D6bW7VMP5q90H/qbsHcB/nZGz+LIx1pBDa4YKGI N9JKhAoczWQR31Y4jrD+CYbcwZdU1pbfp5/dy8rpOuLRT6nWt+4jKJ0tUt56NpD6kWHK XmuQ== X-Gm-Message-State: AOAM533i19UVdHcjHvdwuOu9ElypuQNd2S79tUpiSJB+D1P6bicJ5sbs 1BxJSG5+gibrVZOuP9WkZ/+uCA== X-Google-Smtp-Source: ABdhPJw8jxJQhNhG4kfSYJ0MBaC1k+x/nnPsk0lxjUga8vz1vvxR0wwsMqSTvLdBCryyBHXXJid4OQ== X-Received: by 2002:a05:6638:f89:: with SMTP id h9mr49039087jal.89.1608224109996; Thu, 17 Dec 2020 08:55:09 -0800 (PST) Received: from [192.168.1.30] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id z10sm14438908ioi.47.2020.12.17.08.55.08 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 17 Dec 2020 08:55:09 -0800 (PST) Subject: Re: [PATCH 2/3] blk-mq: Always complete remote completions requests in softirq To: Sebastian Andrzej Siewior , Christoph Hellwig Cc: linux-block@vger.kernel.org, Thomas Gleixner , Peter Zijlstra , Daniel Wagner , Mike Galbraith , Sagi Grimberg References: <20201204191356.2516405-1-bigeasy@linutronix.de> <20201204191356.2516405-3-bigeasy@linutronix.de> <20201208131319.GB22219@infradead.org> <20201217164308.ueki3scv3oxt4uta@linutronix.de> From: Jens Axboe Message-ID: Date: Thu, 17 Dec 2020 09:55:08 -0700 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: <20201217164308.ueki3scv3oxt4uta@linutronix.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 12/17/20 9:43 AM, Sebastian Andrzej Siewior wrote: > On 2020-12-08 13:13:19 [+0000], Christoph Hellwig wrote: >> On Mon, Dec 07, 2020 at 04:52:57PM -0700, Jens Axboe wrote: >>> On 12/4/20 12:13 PM, Sebastian Andrzej Siewior wrote: >>>> Controllers with multiple queues have their IRQ-handelers pinned to a >>>> CPU. The core shouldn't need to complete the request on a remote CPU. >>>> >>>> Remove this case and always raise the softirq to complete the request. >>> >>> I don't like this one at all, it'll add a softirq jump for the fast path >>> for eg nvme devices. >> >> For the real fast path, that is either a polled queue or irq driven >> queues that only map to a single CPU we are never reaching this code, >> so I'm not too worried. Not that I'd complain about numbers, preferably >> in the commit log. > > Did Daniel provide all the numbers you/Jens were looking for or do we > still wait for some? Yeah, I think we're good at this point. I'll queue this up for 5.11. -- Jens Axboe