From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753660AbcKITJU (ORCPT ); Wed, 9 Nov 2016 14:09:20 -0500 Received: from mail-it0-f44.google.com ([209.85.214.44]:38088 "EHLO mail-it0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751317AbcKITJS (ORCPT ); Wed, 9 Nov 2016 14:09:18 -0500 MIME-Version: 1.0 In-Reply-To: References: <1478185120-5509-1-git-send-email-john.garry@huawei.com> From: Dan Williams Date: Wed, 9 Nov 2016 11:09:17 -0800 Message-ID: Subject: Re: [RFC PATCH] scsi: libsas: fix WARN on device removal To: John Garry Cc: "Martin K. Petersen" , jejb@linux.vnet.ibm.com, linux-scsi , john.garry2@mail.dcu.ie, linuxarm@huawei.com, "linux-kernel@vger.kernel.org" , lindar_liu@usish.com, jinpu.wang@profitbricks.com, Tejun Heo Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 9, 2016 at 9:36 AM, John Garry wrote: > On 09/11/2016 12:28, John Garry wrote: >> >> On 03/11/2016 14:58, John Garry wrote: >>> >>> The following patch introduces an annoying WARN >>> when a device is removed from the SAS topology: >>> [SCSI] libsas: prevent domain rediscovery competing with ata error >>> handling >>> >> >> Are there any views on this patch? I would have thought that the parties >> who use the drivers based on libsas would be interested in fixing this >> bug. >> > > I should have added the before and after logs earlier, so the issue is > illustrated. Now attached. When a 24-port expander is unplugged we get >6k > lines of WARN on the console, lasting >30 seconds. Not nice. > I might be mistaken, but this patch seems functionally identical to this attempt: http://marc.info/?l=linux-scsi&m=143459794823595&w=2 i.e. it moves the port destruction to the workqueue and still suffers from the flutter problem: http://marc.info/?l=linux-scsi&m=143801026028006&w=2 http://marc.info/?l=linux-scsi&m=143801971131073&w=2 Perhaps we instead need to quiet this warning? http://marc.info/?l=linux-scsi&m=143802229932175&w=2