On Thu, Apr 06, 2017 at 11:25:42AM +0200, Sebastian Andrzej Siewior wrote:
> > I.e. just have a counter and these two APIs:
> >
> > static inline void migrate_disable(void)
> > {
> > current->migration_disabled++;
> plus
> if (current->migration_disabled == 1)
> get_online_cpus()
You want that other hotplug fast hack crap you have in rt, no? Because
mainline will not get anything other than prempt_disable() for
migrate_disable().
> > }
> >
> > ...
> >
> > static inline void migrate_enable(void)
> > {
> > current->migration_disabled--;
> > }
> >
> > ... and make sure the scheduler migration code plus the CPU hotplug code
> > considers
> > the counter.
>
> So on the sched part I need go through all places where it looks at the
> mask and make sure it ignores the CPU switch decision. This could be
> doable.
Don't sprinkle that around. Use a wrapper like say: tsk_cpus_allowed()
to encapsulate that logic :-)
