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=-5.5 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 50585C388F9 for ; Sat, 31 Oct 2020 15:00:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C6E6206E9 for ; Sat, 31 Oct 2020 15:00:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="JyIEKdEG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727876AbgJaPAw (ORCPT ); Sat, 31 Oct 2020 11:00:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727870AbgJaPAw (ORCPT ); Sat, 31 Oct 2020 11:00:52 -0400 Received: from mail-pl1-x642.google.com (mail-pl1-x642.google.com [IPv6:2607:f8b0:4864:20::642]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 224D0C061A04 for ; Sat, 31 Oct 2020 08:00:52 -0700 (PDT) Received: by mail-pl1-x642.google.com with SMTP id f21so4464026plr.5 for ; Sat, 31 Oct 2020 08:00:52 -0700 (PDT) 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=qXaMQL6RoCeR+mudIFA4Xtm/e3sImcS6WcNnwqQ0dQE=; b=JyIEKdEGhqyOfhEqPSLRNuZB7XXHSH0rNkqv4QqIlBz5yzReIz7XNaXfvOkSTLWaBJ vE72F4+6NuTwikbwzaODM/0HkPqs5OSknMRWm7/1CV+9T4Zvj8J1Tcx2HjykAN18H46T Pz+ItZKLEZkyjzWg2wVQVhW0OA0vqWSXZPFhsMRvN7GHQm/t3qIcb70xPqXj2YM0UWtC wgJbqbmHo+ukwJa3lq9s/i8BhBuhdQt0QYYGDQhVWOFh34KBmJ2oRTWjkLEZfRUo19zV g4bD1jOoiQHVUx+klABS1YrP5pEANXgBmfjW3HgZbDPg9yx5spX60a6oxnQ34npe4Njk 6OJA== 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=qXaMQL6RoCeR+mudIFA4Xtm/e3sImcS6WcNnwqQ0dQE=; b=bRXGrQ+ayp1zwqZYVzbJoETP85WvKn9K06OWT5KhMI96Y9vtutVGk3pkScU0lL8VRM rf7JKyuQpbe8Ms7oO7Foy5JgwccIwFaP2dChByGEt7/cl328eOxftynhZyd4qR3BdcwN AMSFtaN7eXxmJ78+I3r3pwWOVa56WBthrE0dUdGfH88mJhpCVHIRFp6MD0rAI/8Wpv1/ e0iKxIsQzXx+Xeheakhgl+wsEFqbkNfS3GybdWmz6C2Qam9ecyf1y7KwYZQGFfL+KS+M ITSbSxegW/oBCg9TTLnxXc3Z67aS8to8irlnFEQ91YVU/SuasEikbScGX2+6UkP+q5SN y9vw== X-Gm-Message-State: AOAM532PkNWYpEvMCs9iTvJBXRAH+3OWRzj+zRfMyjz5L9DLKqOx0VkJ SUp/o39Xq3//NAkJrCQbsMeZQQ== X-Google-Smtp-Source: ABdhPJwm7j/1DXCTZ42mILmZXxrwO1Vmt4eM1S1RfrfM4xiATEqjowOfuHUe2DQE5Pprkfw/wropig== X-Received: by 2002:a17:902:8548:b029:d6:ac0f:fe78 with SMTP id d8-20020a1709028548b02900d6ac0ffe78mr5919713plo.5.1604156451482; Sat, 31 Oct 2020 08:00:51 -0700 (PDT) Received: from [192.168.1.134] ([66.219.217.173]) by smtp.gmail.com with ESMTPSA id 128sm9054446pfd.110.2020.10.31.08.00.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 31 Oct 2020 08:00:50 -0700 (PDT) Subject: Re: [PATCH 3/3] blk-mq: Use llist_head for blk_cpu_done To: Sebastian Andrzej Siewior , Sagi Grimberg Cc: Christoph Hellwig , linux-block@vger.kernel.org, Thomas Gleixner , David Runge , linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org, Peter Zijlstra , Daniel Wagner , Mike Galbraith References: <20201028065616.GA24449@infradead.org> <20201028141251.3608598-1-bigeasy@linutronix.de> <20201028141251.3608598-3-bigeasy@linutronix.de> <20201029131212.dsulzvsb6pahahbs@linutronix.de> <20201029140536.GA6376@infradead.org> <20201029145623.3zry7o6nh6ks5tjj@linutronix.de> <20201029145743.GA19379@infradead.org> <20201029210103.ocufuvj6i4idf5hj@linutronix.de> <20201031104108.wjjdiklqrgyqmj54@linutronix.de> From: Jens Axboe Message-ID: <3bbfb5e1-c5d7-8f3b-4b96-6dc02be0550d@kernel.dk> Date: Sat, 31 Oct 2020 09:00:49 -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: <20201031104108.wjjdiklqrgyqmj54@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 10/31/20 4:41 AM, Sebastian Andrzej Siewior wrote: > On 2020-10-29 14:07:59 [-0700], Sagi Grimberg wrote: >>> in which context? >> >> Not sure what is the question. > > The question is in which context do you complete your requests. My guess > by now is "usually softirq/NAPI and context in rare error case". There really aren't any rules for this, and it's perfectly legit to complete from process context. Maybe you're a kthread driven driver and that's how you handle completions. The block completion path has always been hard IRQ safe, but possible to call from anywhere. -- Jens Axboe