From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [xen-unstable test] 56759: regressions - FAIL Date: Thu, 11 Jun 2015 09:22:07 -0400 Message-ID: <55798B7F.1060507@citrix.com> References: <1432115769.12989.219.camel@citrix.com> <1432646989.14664.112.camel@citrix.com> <1432742677.14664.270.camel@citrix.com> <1432917126.15036.70.camel@citrix.com> <556DA1DF020000780008020B@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1Z32Xi-0000G2-43 for xen-devel@lists.xenproject.org; Thu, 11 Jun 2015 13:29:14 +0000 In-Reply-To: <556DA1DF020000780008020B@mail.emea.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich , Ian Campbell Cc: Wei Liu , Stefano Stabellini , ian.jackson@eu.citrix.com, Tim Deegan , Julien Grall , David Vrabel , xen-devel List-Id: xen-devel@lists.xenproject.org Hi, On 02/06/2015 06:30, Jan Beulich wrote: >>>> On 29.05.15 at 18:32, wrote: >> On Wed, 2015-05-27 at 17:04 +0100, Ian Campbell wrote: >>> Looking at the netback side though it seems like netback_remove is >>> switching to state=Closed _before_ it calls kobject_uevent(..., >>> KOBJ_OFFLINE) and it is this which generates the call to netback_uevent >>> which tries and fails to read script and produces the error message. >> >> I've just sent out a patch which fixes this issue, although I am still >> at a loss to explain why we have only started seeing this now and only >> under such specific circumstances. >> >>> I'm still slightly concerned that perhaps the new spinlock stuff has >>> some sort of bad behaviour either on arndale specifically or more >>> generally for ARM systems which has pushed this particular case over the >>> edge. >> >> I did run some benchmarks (hackbench+fio on arndale domU and hackbench >> on midway dom0) with and without the ticket locks and the results were >> close enough that I'm basically not too worried that there is something >> wrong with the ticket locks on ARM. >> >> It still niggles somewhat not to have a good theory about why this >> change had this seemingly random effect, but I've not got any good ideas >> for avenues to explore and I've got other things to do so I think I'll >> leave it at that. > > So should we then re-instate the ticket lock patches? Any update on this? Regards, -- Julien Grall