Re: Disabling CPUs

On Sat, Sep 24, 2022 at 12:07 AM Amar Takhar <verm@darkbeer.org> wrote:

> On 2022-09-23 22:58 -0700, Kevin Oberman wrote:
> > Thanks, Amar! I'll give this a try tomorrow.
>
> No problem!
>
> Well, no joy. My BIOS had no ability to disable cores. Confirmed with
Lenovo support. So no ability to do more than cpuset.

>
> > Have you compared performance using only P cores vs. only E cores? My
> testing
> > (using only cpuset) compiles C faster with 8 E cores than 2 P cores (4
> "CPUs").
>
> Well my CPU has 8 P-cores, 16 with HT and then 8 E-cores so I'm always
> going to
> do better with the P cores.  The boost is different on the P cores as well
> and
> I'm using DDR5 memory which is also better from what I've heard with P
> cores.
>

Yes, your system is much bigger than my little Lenovo T16 ThinkPad. I have
11 "CPUs". I always quote those number as there are only cores with
hyperthreading to look like 4 CPUs.

>
>
> > By any chance have you run a VirtualBox VM? I have found that a Windows
> 10 VM
> > loads, but the system panics as soon as the VM starts running. I have a
> couple
> > of things to try that could be triggering the problem. Notably, I have
> 3D HW
> > acceleration enabled and, since it is not available with scfb, it's a
> possible
> > cause.
>
> Oh boy.. I was actually planning on doing this in the next few days Wine
> isn't
> cutting it for a few programs.  I use emulators/libc6-shim/ to turn CUDA
> on for
> my FreeBSD apps and another one for Linux you could try that it's been
> amazing
> to have CUDA on FreeBSD.
>

It may work, but I realized that my 8G of soldered memory is all I have
until my Crucial order arrives with an added 16G of DDR4. I suspect that
there might still be issues, but I won't know until there is enough RAM to
actually load the system. I did see a very consistent  panic at the same
place in the VM code, so it is probably easily traced down if more memory
does not fix it.

>
> > I'm getting tired of trailblazing! My current laptop did not have a
> working Wii
> > interface until iwlwifi. I had seen almost no comments on CURRENT, so I
> had no
> > idea how much trouble I was gettig into.
>
> haha well I still use this as my main workstation it's really annoying
> losing
> 1/2 my cores but it is what it is.  Wait until you get to the sound
> issues.  I
> haven't had time to dig real deep into what's going on with that but it's
> starting to get really annoying as well.  I'm sure this all has the same
> root
> problem.
>

I'm already seeing sound issues, but I have not even looked at them at this
point. This is my main system. Have not used a desktop system since I
retired.

It does appear that the cpuset processor setup does, largely stop the
panics. Stll, the system is not really stable. With both Intel and AMD
committed to mixed speed cores in this and the next generation, these
issues are likely to get serious attention from kernel developers which I
have not been since the end of the 70s when I programmed mostly in assembly
on a variety of platforms. I suspect that serious work is underway. I hope
it comes more quickly than getting graphics support on my 12 year old Sunny
Bridge system where I had to live with VESA for about a year with a 3/4
aspect ratio stretched to fill the 9x16 screen. Really ugly.

Thanks again for your help. I really appreciate it even if it doesn't
resolve my issues.

>
>
> Amar.
>
>

-- 
Kevin Oberman, Part time kid herder and retired Network Engineer
E-mail: rkoberman@gmail.com
PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683