Re: [PATCH v16 12/13] x86/tsc: Switch to native sched clock
From: Borislav Petkov
Date: Tue Jan 07 2025 - 14:38:36 EST
On Mon, Jan 06, 2025 at 06:16:32PM +0530, Nikunj A Dadhania wrote:
> Although the kernel switches over to stable TSC clocksource instead of
> PV clocksource, the scheduler still keeps on using PV clocks as the
> sched clock source. This is because KVM, Xen and VMWare, switch the
> paravirt sched clock handler in their init routines. HyperV is the
> only PV clock source that checks if the platform provides an invariant
> TSC and does not switch to PV sched clock.
So this below looks like some desperate hackery. Are you doing this because
kvm_sched_clock_init() does
paravirt_set_sched_clock(kvm_sched_clock_read);
?
If so, why don't you simply prevent that on STSC guests?
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette