Re: [PATCH 0/9] Add CPU-type to topology

Ricardo Neri
2024-06-27T12:47:35Z

On Wed, Jun 19, 2024 at 03:34:46AM -0700, srinivas pandruvada wrote:

[...]

> >
> > There can be many ways to expose this information in sysfs. Like this
> > ...
> >
> > > [1] https://lkml.org/lkml/2020/10/2/1208
> >
> > ... exposes /sys/devices/system/cpu/types which, in hybrid parts,
> > creates a
> > subdirectory for each type of CPU. Each subdirectory contains a CPU
> > list
> > and a CPU map that user space can query.
> >
> > The other way is to expose the CPU-type in a file:
> >
> >         /sys/devices/system/cpu/cpuN/type
> >
> > that could return the CPU-type of the CPU N. Is there a preference?
>
> But you still have to look at frequency or caches as there are Low
> power E-cores which will have same type but different capabilities.

By the way, /sys/devices/system/cpuN/cache is broken on these systems with
low power Ecores. I proposed a patch to fix it here [B]. May I ask for a few
extra reviews and testing? Perhaps this will raise the confidence of the
x86 maintainers? :)

The patchset continues to apply cleanly on v6.10-rc5.

[B]. https://lore.kernel.org/all/20231212222519.12834-5-ricardo.neri-calderon@linux.intel.com/