TSC as timecounter makes system lag

[Jia-Shiun Li]

On Fri, Feb 24, 2017 at 7:45 PM, Konstantin Belousov <kostikbel at gmail.com>
wrote:

> On Fri, Feb 24, 2017 at 12:15:26PM +0800, Jia-Shiun Li wrote:
> > Tested working on E7400 against r313909. And changing timecounter from/to
> > TSC
> > correctly enables/disables C2.
> >
> > The latter part cpu_disable_c2_sleep++ is not needed. When
> > init_TSC_tc() got called timecounter is not yet tsc_timecounter.
> > inittimecounter() later will do the work calling tc_windup().
> >
>
> You mean, just this
> -       if (cpu_deepest_sleep >= 2 && cpu_vendor_id == CPU_VENDOR_INTEL &&
> +       if (cpu_vendor_id == CPU_VENDOR_INTEL &&
> is enough to fix the issue ?  If yes, we can remove the cpu_deepest_sleep
> variable.  This is John' observation, I think he would prefer to prepare
> the patch.
>

Correct. That's enough.


-Jia-Shiun.