Re: [PATCH][RFC] kvm-scheduler integration

[Ingo Molnar <mingo@elte.hu>]

* Avi Kivity <avi@qumranet.com> wrote:

> +#ifdef CONFIG_SCHED_KVM
> +static __read_mostly struct sched_kvm_hooks kvm_hooks;
> +#endif

please just add a current->put_vcpu() function pointer instead of this 
hooks thing.

>  static inline void prepare_task_switch(struct rq *rq, struct task_struct *next)
>  {
> +	unload_kvm_vcpu(current);
>  	prepare_lock_switch(rq, next);
>  	prepare_arch_switch(next);
>  }
> @@ -1860,6 +1912,7 @@ static inline void finish_task_switch(struct rq *rq, struct task_struct *prev)
>  	prev_state = prev->state;
>  	finish_arch_switch(prev);
>  	finish_lock_switch(rq, prev);
> +	reload_kvm_vcpu(current);

ok, this looks certainly cheap enough from a scheduler POV, and it 
cleans up the whole KVM/scheduling interaction quite nicely. (I'd not 
bother with tweaking the migration logic, there's enough incentive for 
the scheduler to keep tasks from migrating unnecessarily.)

	Ingo