Re: [xen-unstable test] 56759: regressions - FAIL

[Julien Grall <julien.grall@citrix.com>]

Hi,

On 02/06/2015 06:30, Jan Beulich wrote:
>>>> On 29.05.15 at 18:32, <ian.campbell@citrix.com> 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