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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9AEEDE810B2 for ; Wed, 27 Sep 2023 09:41:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230480AbjI0Jl4 (ORCPT ); Wed, 27 Sep 2023 05:41:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45878 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231281AbjI0Jlt (ORCPT ); Wed, 27 Sep 2023 05:41:49 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C98ADC0; Wed, 27 Sep 2023 02:41:47 -0700 (PDT) Received: from kwepemm000012.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4RwWm21jq5zrTBX; Wed, 27 Sep 2023 17:39:30 +0800 (CST) Received: from [10.174.178.220] (10.174.178.220) by kwepemm000012.china.huawei.com (7.193.23.142) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Wed, 27 Sep 2023 17:41:45 +0800 Message-ID: <98ea6e9b-cbfb-0485-6452-e3d979aaed54@huawei.com> Date: Wed, 27 Sep 2023 17:41:44 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: [RFC PATCH v2 00/18] scsi: scsi_error: Introduce new error handle mechanism Content-Language: en-US To: Hannes Reinecke , Mike Christie , Christoph Hellwig CC: "James E . J . Bottomley" , "Martin K . Petersen" , , , , References: <20230901094127.2010873-1-haowenchao2@huawei.com> <47bed3cb-f307-ec55-5c28-051687dab1ea@huawei.com> <06268327-cfed-f266-34a7-fda69411ef2a@huawei.com> From: Wenchao Hao In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.178.220] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemm000012.china.huawei.com (7.193.23.142) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/9/27 15:59, Hannes Reinecke wrote: > On 9/26/23 14:57, Wenchao Hao wrote: >> On 2023/9/26 1:54, Mike Christie wrote: >>> On 9/25/23 10:07 AM, Wenchao Hao wrote: >>>> On 2023/9/25 22:55, Christoph Hellwig wrote: >>>>> Before we add another new error handling mechanism we need to fix the >>>>> old one first.  Hannes' work on not passing the scsi_cmnd to the various >>>>> reset handlers hasn't made a lot of progress in the last five years and >>>>> we'll need to urgently fix that first before adding even more >>>>> complexity. >>>>> >>>> I observed Hannes's patches posted about one year ago, it has not been >>>> applied yet. I don't know if he is still working on it. >>>> >>>> My patches do not depend much on that work, I think the conflict can be >>>> solved fast between two changes. >>> >>> I think we want to figure out Hannes's patches first. >>> >>> For a new EH design we will want to be able to do multiple TMFs in parallel >>> on the same host/target right? >>> >> >> It's not necessary to do multiple TMFs in parallel, it's ok to make sure >> each TMFs do not affect each other. >> >> For example, we have two devices: 0:0:0:0 and 0:0:0:1 >> >> Both of them request device reset, they do not happened in parallel, but >> would in serial. If 0:0:0:0 is performing device reset in progress, 0:0:0:1 >> just wait 0:0:0:0 to finish. >> > Well, not quite. Any higher-order TMFs are serialized by virtue of SCSI-EH, but command aborts (which also devolve down to TMFs on certain drivers) do run in parallel, and there we will be requiring multiple TMFs. > It's best that multiple TMFs can run in parallel, again, looking forwarding to your changes. > Cheers, > > Hannes