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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 E0075C432C3 for ; Mon, 18 Nov 2019 05:32:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C308F20727 for ; Mon, 18 Nov 2019 05:32:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726336AbfKRFc4 (ORCPT ); Mon, 18 Nov 2019 00:32:56 -0500 Received: from mail-pl1-f194.google.com ([209.85.214.194]:37295 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725816AbfKRFc4 (ORCPT ); Mon, 18 Nov 2019 00:32:56 -0500 Received: by mail-pl1-f194.google.com with SMTP id bb5so9090253plb.4; Sun, 17 Nov 2019 21:32:54 -0800 (PST) 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=UXCwpHjv5xl2TWko8v7VBD50UFEr62rmuwQgyE8mtH8=; b=rgyD63+xaSrDYl0MzOYbv8MB22kwjgPga6EmzH0aofHWusRHCfcnpTS6ywllNODsIW cVWnKHlTlfJTgQEuQLJfXjIDcFC7Up7eBs7f/4ZfwVB7k0ZiEwLfwGUjihDeKubcH7cJ ttwiq7Mfvu+kq5Lm5D9APfyQSHGCW5MjFWpsG8BPANTbtCygI3OD5AvPWfz+1yHo6VU5 FVMmIVifsi/e2fZLjEolmDI5GKucyJt1rkKq7nRysaRGvAg6kYJXUovw+oEADnZGG1gu g+9dur7T3pP9+5KBOkZ87XIa9n+Qwkj80MfFVV87c8OTS1TjDiNoYiKZKSXJkSMQOJl7 oJhQ== X-Gm-Message-State: APjAAAX6MYGmSJNA26bpL1yCkWHOM5mPNw0xchVGKkfvp7x7YoKod9L1 LeiZlmMGTDUu3K4H90BJ7CJ8wcEO X-Google-Smtp-Source: APXvYqz0FK0/jLL4CG/wsOpxT9LYNe/f8o1bmSWSIAiUF9U6MIDOWgC/0oJ4UhOnPVyvvPA2qKEY6w== X-Received: by 2002:a17:902:d685:: with SMTP id v5mr25891042ply.188.1574055173986; Sun, 17 Nov 2019 21:32:53 -0800 (PST) Received: from [192.168.3.217] (c-73-241-217-19.hsd1.ca.comcast.net. [73.241.217.19]) by smtp.gmail.com with ESMTPSA id z10sm17855361pgg.39.2019.11.17.21.32.52 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 17 Nov 2019 21:32:52 -0800 (PST) Subject: Re: [PATCH] scsi: core: only re-run queue in scsi_end_request() if device queue is busy To: Ming Lei , linux-scsi@vger.kernel.org, "Martin K . Petersen" Cc: James Bottomley , Jens Axboe , "Ewan D . Milne" , Kashyap Desai , Hannes Reinecke , Damien Le Moal , Long Li , linux-block@vger.kernel.org References: <20191117080818.2664-1-ming.lei@redhat.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: <465632fa-2519-6e44-3a3c-0f81a8e6689e@acm.org> Date: Sun, 17 Nov 2019 21:30:39 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.1 MIME-Version: 1.0 In-Reply-To: <20191117080818.2664-1-ming.lei@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 2019-11-17 00:08, Ming Lei wrote: > diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c > index 379533ce8661..212903d5f43c 100644 > --- a/drivers/scsi/scsi_lib.c > +++ b/drivers/scsi/scsi_lib.c > @@ -612,7 +612,7 @@ static bool scsi_end_request(struct request *req, blk_status_t error, > if (scsi_target(sdev)->single_lun || > !list_empty(&sdev->host->starved_list)) > kblockd_schedule_work(&sdev->requeue_work); > - else > + else if (READ_ONCE(sdev->restart)) > blk_mq_run_hw_queues(q, true); > Rerunning the hardware queues is not only necessary after scsi_dev_queue_ready() returns false but also after .queuecommand() returns SCSI_MLQUEUE_*_BUSY. Can this patch cause queue stalls if .queuecommand() returns SCSI_MLQUEUE_*_BUSY? Thanks, Bart.