Re: Random panic in load_balance() with 3.16-rc

Michel Dänzer
2014-07-24T07:18:59Z

On 23.07.2014 18:31, Michel Dänzer wrote:
> On 23.07.2014 18:25, Peter Zijlstra wrote:
>> On Wed, Jul 23, 2014 at 10:28:19AM +0200, Peter Zijlstra wrote:
>>
>>> Of course, the other thing that patch did is clear sgp->power (now
>>> sgc->capacity).
>>
>> Hmm, re-reading the thread there isn't a clear confirmation its this
>> patch at all. Could you perhaps bisect this to either verify it is
>> indeed that patch we're talking about:
>>
>> caffcdd8d27b ("sched: Do not zero sg->cpumask and sg->sgp->power in build_sched_groups()")
>>
>> or find which patch is causing this.
>
> It can take a long time for the problem to occur, so I need to run at
> least for one or two days to be at least somewhat sure a given kernel is
> not affected.
>
> I'll try reproducing the problem with your previous suggestions first,

Just happened again, with your robustness patch and setting
sg->sgc->capacity = 0.

> but if I manage to do that, I guess there's no alternative to bisecting...

I hope the assembly output I sent earlier helps, I'm afraid bisecting
this could be painful.

--
Earthling Michel Dänzer | http://www.amd.com
Libre software enthusiast | Mesa and X developer