Re: Status of Alder and Raptor lake on FreeBSD Current

On 12 Apr 2023, at 9:59, Dries Michiels wrote:

> Hello current mailing list,
>
> I was wondering what the status of Alder/Raptor lake support is on FreeBSD?
> Does it boot? Integrated graphics are supported from what I recall with the
> newest drm drivers.

-current and 13.2 boot and run on Alder Lake, and probably Raptor Lake (I
haven’t heard of any tests).  There is a bug, probably in hardware, that
affects page invalidation on E-cores, but a workaround changes the mechanism
on the E-cores to compensate.  I have no information on graphics, maybe
someone else does.

> Are there any plans for changes to our scheduler to account for efficiency
> and performance cores?
> Are there real world downsides of not having such a scheduler when running
> an Alder or Raptor lake CPU?

I have been working on scheduler changes, but slowly.  Things work surprisingly
well without them though.  An E-core is slower than the first thread on a
P-core, but faster than the second thread.  The scheduler puts fewer processes
on the E-cores because of the shared cache in groups of 4 CPUs (vs 2 for SMT
on the P-cores).  Of course, with enough processes, they all get used.

> Interested to hear from users using these CPU's right now in there system!
> The Reason I ask is that I'm interested in upgrading my home server
> hardware :-).

I’m running -current on an i7-12700K, and it feels fast compared to my
i7-10700K.

		Mike