On 02/07/2011 03:11 PM, Anthony Liguori wrote:
On 02/07/2011 06:34 AM, Avi Kivity wrote:
On 02/04/2011 10:56 AM, Jan Kiszka wrote:
>
> This should be a rare event. If you are missing 50% of your
> notifications, not amount of gradual catchup is going to help you
out.
But that's the only thing this patch is after: lost ticks at QEMU
level.
Most lost ticks will happen at the vcpu level. The iothread has low
utilization and will therefore be scheduled promptly, whereas the
vcpu thread may have high utilization and will thus be preempted.
When it is preempted for longer than the timer tick, we will see
vcpu-level coalescing. All it takes is 2:1 overcommit to see time go
half as fast; I don't think you'll ever see that on bare metal.
But that's not to say that doing something about lost ticks in QEMU
isn't still useful.
If it doesn't solve the majority of the problems it isn't very useful
IMO. It's a good first step, but not sufficient for real world use with
overcommit.
--
error compiling committee.c: too many arguments to function
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