Re: [PATCH RFC 2/4] Add yield hypercall for KVM guests

[Srivatsa Vaddagiri]

On Mon, Jul 26, 2010 at 10:19:41AM -0700, Jeremy Fitzhardinge wrote:
>  On 07/25/2010 11:14 PM, Srivatsa Vaddagiri wrote:
> >Add KVM hypercall for yielding vcpu timeslice.
> 
> Can you do a directed yield?

We don't have that support yet in Linux scheduler. Also I feel it would be more
useful when the target vcpu and yielding vcpu are on the same physical cpu,
rather than when they are on separate cpus. With latter, yielding (or
donating) timeslice need not ensure that target vcpu runs immediately 
and also I suspect fairness issues needs to be tackled as well (large number of
waiters shouldn't boot a lock-holders time slice too much that it gets a 
larger share).

- vatsa
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/