On Tue, Mar 02 2021 at 10:52, Feng Tang wrote:
> There are cases that tsc clocksource are wrongly judged as unstable by
> clocksource watchdogs like hpet, acpi_pm or 'refined-jiffies'. While
> there is hardly a general reliable way to check the validity of a
> watchdog, and to protect the innocent tsc, Thomas Gleixner proposed [1]:
>
> "I'm inclined to lift that requirement when the CPU has:
>
> 1) X86_FEATURE_CONSTANT_TSC
> 2) X86_FEATURE_NONSTOP_TSC
> 3) X86_FEATURE_NONSTOP_TSC_S3
> 4) X86_FEATURE_TSC_ADJUST
> 5) At max. 4 sockets
>
> After two decades of horrors we're finally at a point where TSC seems
> to be halfway reliable and less abused by BIOS tinkerers. TSC_ADJUST
> was really key as we can now detect even small modifications reliably
> and the important point is that we can cure them as well (not pretty
> but better than all other options)."
>
> So implement it with slight change as discussed in the thread, and be
> more defensive to use maxim of 2 sockets.
Can you please explain the slight change in the changelog?
Thanks,
tglx
