Re: [RFC PATCH] kernel: sched: Provide a pointer to the valid CPU mask

[Peter Zijlstra]

On Thu, Apr 06, 2017 at 10:01:39AM +0200, Ingo Molnar wrote:
> I.e. just have a counter and these two APIs:
> 
>         static inline void migrate_disable(void)
>         {
>                 current->migration_disabled++;
>         }
> 
>         ...
> 
>         static inline void migrate_enable(void)
>         {
>                 current->migration_disabled--;
>         }
> 
> ... and make sure the scheduler migration code plus the CPU hotplug code considers 
> the counter.
> 
> Would this work, and would this be the simplest all around solution?

If you want to add expensive bits to hot paths like wakeups ... :/