Re: [PATCH] KVM: x86: Run PIT work in own kthread

[Avi Kivity <avi@redhat.com>]

On 04/17/2012 02:18 PM, Jan Kiszka wrote:
> On 2012-04-17 12:27, Avi Kivity wrote:
> > On 04/16/2012 09:26 PM, Jan Kiszka wrote:
> >> We can't run PIT IRQ injection work in the interrupt context of the host
> >> timer. This would allow the user to influence the handler complexity by
> >> asking for a broadcast to a large number of VCPUs. Therefore, this work
> >> was pushed into workqueue context in 9d244caf2e. However, this prevents
> >> prioritizing the PIT injection over other task as workqueues share
> >> kernel threads.
> >>
> >> This replaces the workqueue with a kthread worker and gives that thread
> >> a name in the format "kvm-pit/<owner-process-pid>". That allows to
> >> identify and adjust the kthread priority according to the VM process
> >> parameters.
> > 
> > Is this a new ABI?
>
> Yep. Scripts will use it, maybe even QEMU. Do you want this to appear in
> api.txt?

You already know the answer.

Please make it explicit that the thread is optional.  This way, if we
gain real-time workqueue support, or eliminate it through some other
trick, userspace won't break.

-- 
error compiling committee.c: too many arguments to function