Re: [PATCH 1/3] kernel/sched: introduce vcpu preempted check interface

From: Peter Zijlstra
Date: Mon Jun 27 2016 - 10:03:16 EST


On Mon, Jun 27, 2016 at 04:00:43PM +0200, Peter Zijlstra wrote:
> On Mon, Jun 27, 2016 at 01:41:28PM -0400, Pan Xinhui wrote:
> > +++ b/include/linux/sched.h
> > @@ -3293,6 +3293,15 @@ static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
> >
> > #endif /* CONFIG_SMP */
> >
> > +#ifdef arch_vcpu_is_preempted
> > +static inline bool vcpu_is_preempted(int cpu)
> > +{
> > + return arch_vcpu_is_preempted(cpu);
> > +}
> > +#else
> > +#define vcpu_is_preempted(cpu) false
> > +#endif
>
> #ifndef vcpu_is_preempted
> #define vcpu_is_preempted(cpu) (false)
> #endif
>
> Is so much simpler...
>
> Also, please Cc the virt list so that other interested parties can
> comment, and maybe also the s390 folks.

And before you hurry off to post again, add a patch doing
mutex_spin_on_owner() and rwsem_spin_in_owner().