Re: [PATCH] sched: introduce configurable delay before entering idle

[Wanpeng Li]

On Mon, 13 May 2019 at 19:52, Raslan, KarimAllah <karahmed@xxxxxxxxx> wrote:
>
> On Mon, 2019-05-13 at 07:31 -0400, Konrad Rzeszutek Wilk wrote:
> > On May 13, 2019 5:20:37 AM EDT, Wanpeng Li <kernellwp@xxxxxxxxx> wrote:
> > >
> > > On Wed, 8 May 2019 at 02:57, Marcelo Tosatti <mtosatti@xxxxxxxxxx>
> > > wrote:
> > > >
> > > >
> > > >
> > > > Certain workloads perform poorly on KVM compared to baremetal
> > > > due to baremetal's ability to perform mwait on NEED_RESCHED
> > > > bit of task flags (therefore skipping the IPI).
> > >
> > > KVM supports expose mwait to the guest, if it can solve this?
> > >
> >
> >
> > There is a bit of problem with that. The host will see 100% CPU utilization even if the guest is idle and taking long naps..
> >
> > Which depending on your dashboard can look like the machine is on fire.
>
> This can also be fixed. I have a patch that kind of expose proper information
> about the *real* utilization here if that would be help.

You can have a post.

Regards,
Wanpeng Li