Re: [PATCH v5 UPDATEDv3 3/3] CPU hotplug, smp: Flush any pending IPI callbacks before CPU offline

[Srivatsa S. Bhat]

On 05/20/2014 03:55 PM, Peter Zijlstra wrote:
> On Tue, May 20, 2014 at 03:39:59PM +0530, Srivatsa S. Bhat wrote:
>>> The multi_cpu_stop() path isn't exclusive to hotplug, so your changelog
>>> is wrong or the patch is.
>>>
>>
>> Yes, I know that multi_cpu_stop() isn't exclusive to hotplug. That's why
>> I have explicitly referred to CPU hotplug in the comment as well as the
>> changelog.
>>
>> But I totally agree that code-wise this is not the best way to do it since
>> this affects (although harmlessly) usecases other than hotplug as well.
>>
>> Do you have any other suggestions?
> 
> How about making a kernel/smp.c hotplug notifier and stuffing it in the
> CPU_DYING list? That's typically after we've already torn down the
> interrupts for that cpu, so no chance of any new ones coming in.
> 
> Or is that too late?
> 

No, that should work just fine. Thank you for the suggestion! I'll give
it a shot.

Regards,
Srivatsa S. Bhat

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/