Re: AMD Pstate

Mike Lothian
2021-11-23T11:22:38Z

On Tue, 23 Nov 2021 at 11:18, Huang Rui <ray.huang@amd.com> wrote:
>
> On Tue, Nov 23, 2021 at 06:47:34PM +0800, Mike Lothian wrote:
> > Hi again
> >
> > Do I need to enable something else for shedutil to work, I've tried
> > with and without shared_mem? Compiling a kernel with -j16 has the freq
> > stuck at 1GHz on all cores - ondemand works fine
> >
>
> If you set the CONFIG_CPU_FREQ_GOV_SCHEDUTIL, then no more configurations.
>
> Did you use the V4 version?
>
> https://git.kernel.org/pub/scm/linux/kernel/git/rui/linux.git/log/?h=amd-pstate-dev-v4
>
> > That's on a AMD Ryzen 9 5900HX
> >
> > Also compiling with Clang-13 gives the following warnings:
> >
> > drivers/cpufreq/amd-pstate.c:257:6: warning: variable 'amd_des_perf'
> > is used uninitialized whenever 'if' condition is false
> > [-Wsometimes-uninitialized]
> >
> > if (target_perf < capacity)
> >
> > ^~~~~~~~~~~~~~~~~~~~~~
> >
> > drivers/cpufreq/amd-pstate.c:272:40: note: uninitialized use occurs here
> >
> > amd_des_perf = clamp_t(unsigned long, amd_des_perf,
> >
> > ^~~~~~~~~~~~
>
> Ah, miss one line. Thanks for the info. I will correct it.
>
> Thanks,
> Ray
>

Hi

Yes I used v4 and CONFIG_CPU_FREQ_GOV_SCHEDUTIL was set as the
default, is there any other info that would be useful, I can switch
back to schedutil from ondemand and collect for you

Cheers

Mike