Re: tip.today - scheduler bam boom crash (cpu hotplug)

[Peter Zijlstra]

On Mon, Feb 27, 2017 at 09:48:35PM +0800, Wanpeng Li wrote:
> 2017-02-27 20:43 GMT+08:00 Peter Zijlstra <peterz@xxxxxxxxxxxxx>:
> > I have no clue what that tries to do.
> 
> The patch tries to mark sched clock stable if
> KVM_FEATURE_CLOCKSOURCE_STABLE_BIT / PVCLOCK_TSC_STABLE_BIT is set in
> kvm guest even if there is no invariant tsc cpuid bit.

I just ripped out the interface to 'set stable' for good reasons. Also,
the branch you add it to doesn't in fact do clear_stable -- so who does?

Also, the sched/clock.c code shouldn't know about hypervisor anything.

So whatever it is you're doing, you're doing it wrong.