On 6 Feb 2023, at 16:04, mike tancsa wrote:
> Hi All,
>
> I have seen a couple of commits around these CPUs, but wondering if
> anyone is running 13 on these newer hybrid CPUs ? Do the slower cores just
> get disabled or are they made use of somehow ?
>
> ---Mike
I have been testing the changes on -current, and they are working fine. I have
not tested on 13, but I would expect the same result. The workaround is on
13-stable, but not yet a RELENG branch. Presumably it will be in 13.2 when it
is branched. If no one else has reported, I will test the 13.2 branch. Also,
I haven’t heard of tests on Raptor Lake, but I have heard that the behavior
should be the same as Alder Lake.
The E-cores are not disabled. They are forced to use a less efficient method
of page invalidation. They are scheduled as if they were P-cores without
threads, but they are less used because of the shared cache among 4 cores
rather than 2. I have some preliminary scheduler changes that recognize the
slower cores, but there are still issues to be dealt with.
Mike
