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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 439B9C2BB86 for ; Sat, 11 Apr 2020 23:21:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 26AB120769 for ; Sat, 11 Apr 2020 23:21:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730844AbgDKXVV (ORCPT ); Sat, 11 Apr 2020 19:21:21 -0400 Received: from mail-pj1-f68.google.com ([209.85.216.68]:40013 "EHLO mail-pj1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730168AbgDKXVU (ORCPT ); Sat, 11 Apr 2020 19:21:20 -0400 Received: by mail-pj1-f68.google.com with SMTP id kx8so2257819pjb.5; Sat, 11 Apr 2020 16:21:20 -0700 (PDT) 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:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=OnEdTEw0ywKO3uB4jy60eHyGZ2CxASOjH3gei6SJ2NA=; b=CLW4WlEqBrfZv5Svthez2gKoMv7rr2oU91bLRK+SFKK+PvJ4f+a8sB5XvTvZRk4v4W HdqChL8Qg9UcHZJdy0C9zEQB7xAtzPtev97WkZM5f5yqhrf3y4YEa9Hvvw4g4c58gHDK MQzx2/GzjGogdL6HNXAlu3qBL8rjcoPK5exFUZc/KCH91kgrKFKjIgGNIFSyxFcT9OQ5 NSX1pbN0jZXaCcNnUr7Y3IqsNOfuzvPX6ZUN5I9jCpSuK3JJNIHD8df4SprwzJrFy1cM NGyKHK3aLwwu2r4iS2swRPmlOgmSooY6cCvuXw596REi2pU1mZR3lGH1aZVy7ibrWDg1 PGZw== X-Gm-Message-State: AGi0PuYeEbcplONJeWF7FWttgub8C+sO7IgBH5QnjScMhHDjyhMxnpgB aa9GLRDWEqBxawo7Eqd2E6s= X-Google-Smtp-Source: APiQypLHqz4km5FIo2c058vEcQtuJ+/nXQ2X5Otv+2Z17DtjYXioxzZtjN80ODAcjm06XLNBW3C4EQ== X-Received: by 2002:a17:902:ba14:: with SMTP id j20mr10464925pls.69.1586647279530; Sat, 11 Apr 2020 16:21:19 -0700 (PDT) Received: from ?IPv6:2601:647:4000:d7:c9fa:49a8:1701:9c75? ([2601:647:4000:d7:c9fa:49a8:1701:9c75]) by smtp.gmail.com with ESMTPSA id e7sm5117580pfj.97.2020.04.11.16.21.17 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 11 Apr 2020 16:21:18 -0700 (PDT) Subject: Re: [RFC v2 5/5] block: revert back to synchronous request_queue removal To: Luis Chamberlain Cc: Jens Axboe , Al Viro , Greg Kroah-Hartman , Steven Rostedt , Ingo Molnar , Jan Kara , Ming Lei , Nicolai Stange , Andrew Morton , Michal Hocko , yu kuai , linux-block@vger.kernel.org, Linux FS Devel , linux-mm , "linux-kernel@vger.kernel.org" , Omar Sandoval , Hannes Reinecke , Michal Hocko References: <20200409214530.2413-1-mcgrof@kernel.org> <20200409214530.2413-6-mcgrof@kernel.org> <161e938d-929b-1fdb-ba77-56b839c14b5b@acm.org> <20200410143412.GK11244@42.do-not-panic.com> From: Bart Van Assche Autocrypt: addr=bvanassche@acm.org; prefer-encrypt=mutual; keydata= mQENBFSOu4oBCADcRWxVUvkkvRmmwTwIjIJvZOu6wNm+dz5AF4z0FHW2KNZL3oheO3P8UZWr LQOrCfRcK8e/sIs2Y2D3Lg/SL7qqbMehGEYcJptu6mKkywBfoYbtBkVoJ/jQsi2H0vBiiCOy fmxMHIPcYxaJdXxrOG2UO4B60Y/BzE6OrPDT44w4cZA9DH5xialliWU447Bts8TJNa3lZKS1 AvW1ZklbvJfAJJAwzDih35LxU2fcWbmhPa7EO2DCv/LM1B10GBB/oQB5kvlq4aA2PSIWkqz4 3SI5kCPSsygD6wKnbRsvNn2mIACva6VHdm62A7xel5dJRfpQjXj2snd1F/YNoNc66UUTABEB AAG0JEJhcnQgVmFuIEFzc2NoZSA8YnZhbmFzc2NoZUBhY20ub3JnPokBOQQTAQIAIwUCVI67 igIbAwcLCQgHAwIBBhUIAgkKCwQWAgMBAh4BAheAAAoJEHFcPTXFzhAJ8QkH/1AdXblKL65M Y1Zk1bYKnkAb4a98LxCPm/pJBilvci6boefwlBDZ2NZuuYWYgyrehMB5H+q+Kq4P0IBbTqTa jTPAANn62A6jwJ0FnCn6YaM9TZQjM1F7LoDX3v+oAkaoXuq0dQ4hnxQNu792bi6QyVdZUvKc macVFVgfK9n04mL7RzjO3f+X4midKt/s+G+IPr4DGlrq+WH27eDbpUR3aYRk8EgbgGKvQFdD CEBFJi+5ZKOArmJVBSk21RHDpqyz6Vit3rjep7c1SN8s7NhVi9cjkKmMDM7KYhXkWc10lKx2 RTkFI30rkDm4U+JpdAd2+tP3tjGf9AyGGinpzE2XY1K5AQ0EVI67igEIAKiSyd0nECrgz+H5 PcFDGYQpGDMTl8MOPCKw/F3diXPuj2eql4xSbAdbUCJzk2ETif5s3twT2ER8cUTEVOaCEUY3 eOiaFgQ+nGLx4BXqqGewikPJCe+UBjFnH1m2/IFn4T9jPZkV8xlkKmDUqMK5EV9n3eQLkn5g lco+FepTtmbkSCCjd91EfThVbNYpVQ5ZjdBCXN66CKyJDMJ85HVr5rmXG/nqriTh6cv1l1Js T7AFvvPjUPknS6d+BETMhTkbGzoyS+sywEsQAgA+BMCxBH4LvUmHYhpS+W6CiZ3ZMxjO8Hgc ++w1mLeRUvda3i4/U8wDT3SWuHcB3DWlcppECLkAEQEAAYkBHwQYAQIACQUCVI67igIbDAAK CRBxXD01xc4QCZ4dB/0QrnEasxjM0PGeXK5hcZMT9Eo998alUfn5XU0RQDYdwp6/kMEXMdmT oH0F0xB3SQ8WVSXA9rrc4EBvZruWQ+5/zjVrhhfUAx12CzL4oQ9Ro2k45daYaonKTANYG22y //x8dLe2Fv1By4SKGhmzwH87uXxbTJAUxiWIi1np0z3/RDnoVyfmfbbL1DY7zf2hYXLLzsJR mSsED/1nlJ9Oq5fALdNEPgDyPUerqHxcmIub+pF0AzJoYHK5punqpqfGmqPbjxrJLPJfHVKy goMj5DlBMoYqEgpbwdUYkH6QdizJJCur4icy8GUNbisFYABeoJ91pnD4IGei3MTdvINSZI5e Message-ID: <64c9212d-aaa3-d172-0ab9-0fc0e25a019a@acm.org> Date: Sat, 11 Apr 2020 16:21:17 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 2020-04-10 14:27, Luis Chamberlain wrote: > On Fri, Apr 10, 2020 at 2:50 PM Luis Chamberlain wrote: >> >> On Fri, Apr 10, 2020 at 8:34 AM Luis Chamberlain wrote: >>> On Thu, Apr 09, 2020 at 08:12:21PM -0700, Bart Van Assche wrote: >>>> Please add a might_sleep() call in blk_put_queue() since with this patch >>>> applied it is no longer allowed to call blk_put_queue() from atomic context. >>> >>> Sure thing. >> >> On second though, I don't think blk_put_queue() would be the right >> place for might_sleep(), given we really only care about the *last* >> refcount decrement to 0. So I'll move it to blk_release_queue(). >> Granted, at that point we are too late, and we'd get a splat about >> this issue *iff* we really sleep. So yeah, I do suppose that forcing >> this check there still makes sense. > > I'll add might_sleep() to both blk_release_queue() *and* blk_cleanup_queue(). Since there is already an unconditional mutex_lock() call in blk_cleanup_queue(), do we really need to add a might_sleep() call in blk_cleanup_queue()? Thanks, Bart.