Re: [PREEMPT-RT] [PATCH] s390/cpum_sf: Remove superfluous SMP function call

[Sebastian Andrzej Siewior]

On 04/05/2016 01:51 PM, rcochran@xxxxxxxxxxxxx wrote:
> On Tue, Apr 05, 2016 at 01:36:38PM +0200, Heiko Carstens wrote:
>> On Tue, Apr 05, 2016 at 01:23:36PM +0200, Heiko Carstens wrote:
>>> Subsequently, in this case, the setup_pmc_cpu() call will be executed on
>>> the wrong cpu.
>>
>> .. or to illustrate this behaviour: the following patch (white space
>> damaged due to copy-paste) results in the following:
> 
> I guess you are missing the following commit?
…
>     cpu/hotplug: Move online calls to hotplugged cpu

No, Heiko is right here. If one of the "CPU_DOWN_PREPARE" fails then
the following CPU_DOWN_FAILED will be invoked on the correct CPU.

However if we are further down the road and the final ARCH specific
"die" failed (just before CPU_DYING) are invoked then we get this done
on the wrong CPU.

> Thanks,
> Richard

Sebastian