From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Anderson Subject: Re: scsi: aic7xxx hang since v2.6.28-rc1 ... Date: Wed, 18 Feb 2009 11:16:43 -0800 Message-ID: <20090218191643.GA16347@linux.vnet.ibm.com> References: <20090215115823.GB19464@elte.hu> <20090218155817.GC23989@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from e36.co.us.ibm.com ([32.97.110.154]:51426 "EHLO e36.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751881AbZBRTRC (ORCPT ); Wed, 18 Feb 2009 14:17:02 -0500 Content-Disposition: inline In-Reply-To: <20090218155817.GC23989@elte.hu> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Ingo Molnar Cc: Alan Stern , linux-scsi@vger.kernel.org, James Bottomley , Jens Axboe , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org Ingo Molnar wrote: > > * Alan Stern wrote: > > > I have no idea if this will make any difference for the > > problem you're seeing, but it has been submitted and it's > > worth trying out. If the problem still occurs, I'll write a > > diagnostic patch to add log messages giving the destiny of > > each request in scsi_io_completion(). > > OK, i've undone the reverts and have applied your fix - it will > take a few hours to see whether the hang still occurs. > I know already started your testing, but.. I find it informative to set my scsi logging to the value below to display non-zero IO status on commands. The overhead impact is low for good completions. sysctl -w dev.scsi.logging_level=4100 Note: This does not provide the exact policy that scsi_io_completion will take on the IO, but it provides the input to scsi_io_completion which should help. -andmike -- Michael Anderson andmike@linux.vnet.ibm.com