Re: EST available frequencies drops during operation

[David Brownlee <abs%absd.org@localhost>]

On Sun, 26 Jan 2020 at 06:14, Matthias Petermann <mp%petermann-it.de@localhost> wrote:
>
> Hello everybody,
>
> on my Lenovo X230 (Intel Core i5-3320M CPU @ 2.60GHz) with NetBSD
> 9.0_RC1 (amd64) I have made a strange observation several times.
> Especially under high load (the CPU temperature was well over 90 degrees
> Celsius), the computer seemed to be very slow, even after the load
> decreased.
>
> The reason seems to be as follows. Under normal conditions I get:
>
>      x230Mk4$ sysctl machdep.est.frequency.available
>      machdep.est.frequency.available = 2601 2600 2500 2400 2300 2200
> 2100 2000 1900 1800 1700 1600 1500 1400 1300 1200
>
> In the situation described above, I get:
>
>      x230Mk4$ sysctl machdep.est.frequency.available
>      machdep.est.frequency.available = 1200
>
> It seems as if the available clock frequencies are dropped during
> operation, so that the computer / OS can no longer clock itself to a
> higher step. After a reboot, everything has become normal again.
>
> Another note: I have the feeling that the problem occurs frequently when
> I use Qemu VMs (with nvmm) - in my case especially Windows 10 32 bit. It
> could of course be the nature that Qemu generates a lot of load and that
> this is a thermal problem. In the meantime, I have set estd so that
> frequencies above 2200 MHz are avoided, hoping to get overheating under
> control and not get the problem. So far, that hasn't really helped.
>
> Has anyone ever observed something like this and knows advice?

I saw something similar on a T430 under NetBSD-8, I *think* most often
after suspect/resume, possibly when the battery was towards the lower
end.

Not more than another data point unfortunately

David