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=-2.3 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 9FC5BC54FD0 for ; Thu, 23 Apr 2020 17:57:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E36A2076C for ; Thu, 23 Apr 2020 17:57:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730107AbgDWR5Z (ORCPT ); Thu, 23 Apr 2020 13:57:25 -0400 Received: from mail-pf1-f194.google.com ([209.85.210.194]:38270 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729991AbgDWR5X (ORCPT ); Thu, 23 Apr 2020 13:57:23 -0400 Received: by mail-pf1-f194.google.com with SMTP id y25so3336085pfn.5; Thu, 23 Apr 2020 10:57:23 -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:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=daGbqtibwc35BdsMcdFSyIPRGTwwJ3IBA05IlTqZ6d8=; b=I43wCRcz1amw60Iwve4JvxqA0ScjeazRbVV66+rZ9KoEKP6dec+I/ctur/ENwEayQd ndcOGMM5kAKgqghrlaS7J9HvQVJYjAy6nidPGH5+8Dr9GqpLdGOWWNOWRG5S1K62wF39 efmwdmjlWalGp5CC0Y3eZARAOGixD6hQFYzX9CD+fhMRAlz7FYpb9xXhkltcEW5cbiAJ LnXnYTzvYGCXOkIn1bWLcztwpbhL8esRb3nFngfUt9O5vsZFtptGjOOadslo9gRc1jhE qmD8qLMnsdn0j+1dKjipqtS4MNfhQF5xefV+z4pymKvXML8QU6OlrbLmo898Gs+WwKmn dj4Q== X-Gm-Message-State: AGi0PuaVsQ1z841mO2Aeug2Xdv2fvlfqXjJ2oyJA5aErp+r4wu0b8zYr BWnKiu3Iiy8bnNp5Y4Z++Ez18SGX1ZI= X-Google-Smtp-Source: APiQypJ55IrIhgkLR0B2lVLW2yZ5mX8SXZEg7Y6hVIE2B8F13QM14Fh+Px7JmoDMASkcC5LEUuMrEw== X-Received: by 2002:a63:1e0f:: with SMTP id e15mr4904610pge.240.1587664642229; Thu, 23 Apr 2020 10:57:22 -0700 (PDT) Received: from [100.124.9.89] ([104.129.198.56]) by smtp.gmail.com with ESMTPSA id w185sm2622217pgb.12.2020.04.23.10.57.19 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 23 Apr 2020 10:57:20 -0700 (PDT) Subject: Re: [EXT] Re: [PATCH v2 1/5] scsi; ufs: add device descriptor for Host Performance Booster To: "Bean Huo (beanhuo)" , "huobean@gmail.com" , "alim.akhtar@samsung.com" , "avri.altman@wdc.com" , "asutoshd@codeaurora.org" , "jejb@linux.ibm.com" , "martin.petersen@oracle.com" , "stanley.chu@mediatek.com" , "tomas.winkler@intel.com" , "cang@codeaurora.org" Cc: "linux-scsi@vger.kernel.org" , "linux-kernel@vger.kernel.org" References: <20200416203126.1210-1-beanhuo@micron.com> <20200416203126.1210-2-beanhuo@micron.com> <6e092ac1-7e7d-3f12-8c81-b88369f1f621@acm.org> From: Bart Van Assche Message-ID: <2625027d-8d98-3f30-93d4-dc1c39a434f1@acm.org> Date: Thu, 23 Apr 2020 10:57:17 -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; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/23/20 4:01 AM, Bean Huo (beanhuo) wrote: > Thanks your review, I will take your suggestions in next version development. Hi Bean, Please make sure that the issues raised by Christoph are addressed before reposting this series. Additionally, I think the following two call chains are deadlock-prone and should be addressed: ufshcd_queuecommand() -> ufshcd_comp_scsi_upiu() -> ufshpb_prep_fn() -> schedule_work(&hpb->ufshpb_req_work) -> ufshpb_req_workq_fn() -> ufshpb_subregion_activate() -> ufshpb_subregion_l2p_load() -> ufshpb_l2p_load_req() -> blk_execute_rq_nowait() ufshcd_queuecommand() -> ufshcd_comp_scsi_upiu() -> ufshpb_prep_fn() -> schedule_work(&hpb->ufshpb_req_work) -> ufshpb_req_workq_fn() -> ufshpb_subregion_activate() -> ufshpb_region_deactivate() -> ufshpb_execute_cmd() -> scsi_execute() I don't know any other block or SCSI driver that calls blk_execute_rq*() or scsi_execute() from inside its .queue_rq() callback to queue requests onto the same request queue (the device mapper requeues requests onto a lower level request queue). Thanks, Bart.