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 818DEC433EF for ; Tue, 31 May 2022 15:26:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345648AbiEaP0d (ORCPT ); Tue, 31 May 2022 11:26:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59944 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235321AbiEaP0b (ORCPT ); Tue, 31 May 2022 11:26:31 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6E9C13617B for ; Tue, 31 May 2022 08:26:30 -0700 (PDT) Received: from fraeml745-chm.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4LCGLp0rcjz67mqV; Tue, 31 May 2022 23:25:38 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml745-chm.china.huawei.com (10.206.15.226) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 31 May 2022 17:26:27 +0200 Received: from [10.47.88.115] (10.47.88.115) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 31 May 2022 16:26:27 +0100 Message-ID: <0ebd951e-f047-1930-4ace-f5199921bf9a@huawei.com> Date: Tue, 31 May 2022 16:26:26 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [PATCH 01/10] scsi/mvsas: Kill CONFIG_SCSI_MVSAS_TASKLET To: Sebastian Andrzej Siewior CC: Davidlohr Bueso , , , , References: <20220530231512.9729-1-dave@stgolabs.net> <20220530231512.9729-2-dave@stgolabs.net> <17747966-ea44-ebe5-3d79-df7c33b6a16e@huawei.com> <20220531145231.opypdzrlrg23ihil@offworld> <5d28e848-0b9d-2aaa-e00e-7888342d25a7@huawei.com> From: John Garry In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.47.88.115] X-ClientProxiedBy: lhreml730-chm.china.huawei.com (10.201.108.81) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 31/05/2022 16:17, Sebastian Andrzej Siewior wrote: >> Sorry, maybe I was not clear, but I was just asking if there was a good >> reason to disable interrupts at source while handling the interrupt, and not >> the change to stop using a tasklet. > Without reading the patch first: You need to disable the interrupt > source while the tasklet/ threaded interrupt is handled. Otherwise the > interrupt will keep coming and the tasklet/ threaded interrupt will have > no chance to make progress. So the box will lock up. This is often > overseen on fast machines because the interrupt needs a few usecs to > trigger and so the CPU is able to make a little bit of progress between > each trigger. > ah, so we would need IRQF_ONESHOT flag set to keep the interrupt line disabled until the threaded part completes, right? Thanks, John