Re: [PATCH v9 1/3] smpboot: allow excluding cpus from the smpboot threads

Chris Metcalf
2015-04-30T16:07:34Z

On 04/29/2015 06:26 PM, Andrew Morton wrote:
> On Fri, 17 Apr 2015 14:37:16 -0400 Chris Metcalf <cmetcalf@ezchip.com> wrote:
>
>> This change allows some cores to be excluded from running the
>> smp_hotplug_thread tasks. The following commit to update
>> kernel/watchdog.c to use this functionality is the motivating
>> example, and more information on the motivation is provided there.
>>
>> A new smp_hotplug_thread field is introduced, "cpumask", which
>> is cpumask field managed by the smpboot subsystem that indicates whether
>> or not the given smp_hotplug_thread should run on that core; the
>> cpumask is checked when deciding whether to unpark the thread.
>>
>> To limit the cpumask to less than cpu_possible, you must call
>> smpboot_update_cpumask_percpu_thread() after registering.
> Has Thomas commented on any version of this? t'would be nice.

He offered some specific feedback here:

https://lkml.org/lkml/2015/4/8/684

that I reflected in the subsequent iteration of the patch series.

Thomas, any additional feedback would be appreciated.

--
Chris Metcalf, EZChip Semiconductor