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, 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 CDC04C2D0A3 for ; Thu, 12 Nov 2020 15:29:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 70C8C20A8B for ; Thu, 12 Nov 2020 15:29:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728542AbgKLP3S (ORCPT ); Thu, 12 Nov 2020 10:29:18 -0500 Received: from mail-pl1-f193.google.com ([209.85.214.193]:44486 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727932AbgKLP3R (ORCPT ); Thu, 12 Nov 2020 10:29:17 -0500 Received: by mail-pl1-f193.google.com with SMTP id b3so2932463pls.11 for ; Thu, 12 Nov 2020 07:29:17 -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:from:to:cc:references:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=mfWwkX2VqCJnpSe3f6b7gGDcCnnDVIbQGc+a3cLC1XQ=; b=ctj7g/mJPP+EdpF4mDTw1CS64m7osdFgApwoi5GJtCzW9Sk25imV4b4WOm5ydCIX49 yPHjcrcaCtB/R6jy8UmJtxurW3rQ7SNa/VvJuNmXeBSRgCx2Y/jtJ6IY+BQBsBIAoXnp G3htLrg2Qi4j8GbPsdSoNS9zwqeJ06CNCx1Yrs0Co7KehsQ50K1JIuIBFP98tCwB+yAF 4r4ix5c+EnxWQBRR/U9/YT0uvz17P+3tj8Jz9VhW1EluplraFiUVnYZ4ol/kwPhWQJx3 7c/5nrfv55ab8LiUF+Od2cuaqck45Srtpg8HurDmucbuuIyhU6dXRSJ71tNsNsvwWWK3 vfXA== X-Gm-Message-State: AOAM531o/6aSnlYbRd1pSOJeI9+lxznyNC9wy0pze8k30Jr4sw13HtfR e0rkN7EqlQNieE7jtWccGoc= X-Google-Smtp-Source: ABdhPJxOj52iktluMxLhGtb7Uxm7Tvphkd8qB2HY4bWSTc9zsAj9RHsxcwe7GxmwCtCA92aOoYD40A== X-Received: by 2002:a17:902:a608:b029:d6:a1fc:ab75 with SMTP id u8-20020a170902a608b02900d6a1fcab75mr247999plq.18.1605194956874; Thu, 12 Nov 2020 07:29:16 -0800 (PST) Received: from [192.168.3.218] (c-73-241-217-19.hsd1.ca.comcast.net. [73.241.217.19]) by smtp.gmail.com with ESMTPSA id j1sm6672257pfa.96.2020.11.12.07.29.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 12 Nov 2020 07:29:15 -0800 (PST) Subject: Re: [PATCH 3/3] Revert "block: Fix a lockdep complaint triggered by request queue flushing" From: Bart Van Assche To: Ming Lei , Jens Axboe , linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, Christoph Hellwig Cc: Qian Cai , Sumit Saxena , John Garry , Kashyap Desai , Hannes Reinecke References: <20201112075526.947079-1-ming.lei@redhat.com> <20201112075526.947079-4-ming.lei@redhat.com> <43bd8381-487b-098d-8e62-3946c75bcd8a@acm.org> Message-ID: Date: Thu, 12 Nov 2020 07:29:13 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: <43bd8381-487b-098d-8e62-3946c75bcd8a@acm.org> 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 11/12/20 7:12 AM, Bart Van Assche wrote: > On 11/11/20 11:55 PM, Ming Lei wrote: >> This reverts commit b3c6a59975415bde29cfd76ff1ab008edbf614a9. >> >> Now we can avoid nvme-loop lockdep warning of 'lockdep possible recursive >> locking' by nvme-loop's lock class, no need to apply dynamically >> allocated lock class key, so revert commit b3c6a5997541("block: Fix a >> lockdep complaint triggered by request queue flushing"). >> >> This way fixes horrible SCSI probe delay issue on megaraid_sas, and it >> is reported the whole probe may take more than half an hour. > > The code touched by this patch is compiled out with locked disabled so > it is not clear to me how this patch could affect a probe delay for > megaraid_sas? Has the megaraid_sas probe issue perhaps not been root > caused correctly? (replying to my own email) I found the answer in the descriptions of the previous patches of this series. I think this patch would benefit from a more complete patch description. Thanks, Bart.