Re: [PATCH v2 05/13] platform/x86: hfi: Introduce AMD Hardware Feedback Interface Driver
From: Mario Limonciello
Date: Fri Oct 18 2024 - 09:47:33 EST
On 10/17/2024 18:33, Ricardo Neri wrote:
On Tue, Oct 15, 2024 at 01:09:42PM -0500, Mario Limonciello wrote:
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
I tried to find the HFI details on the documents in this "bug" but I could
not find them. What document in specific could I look at?
Thanks and BR,
Ricardo
Hi Ricardo,
It is spread out across multiple places. This is part of the reason for
patch 1 in the series outlines details of how it works.
The reason for that "collect all" Bugzilla for documentation is because the
URLs for AMD documentation have undergone changes in the past and it makes
it difficult to put stable URLs in commit messages. So teams that want to
reference documentation put it on a dump all bug for a stable URL to
reference.
On that link you will find the APM, which will have some documentation
specifically for the CPUID leafs used for topology identification and
clearing history.
Read patch 1 and let me know if it covers what specifically you're looking
for. If it's still missing some info let me know what you would like added.
Thank you for your reply! I read patch 1. I was wondering specifically about
more details of the Class ID. I see that they have associated counters and
desired scheduling behavior.
Ah thanks! Obviously in this version there is no utilization of the
classifications, so this was an oversight. This is something that we'll
worry about after the baseline support is landed.
I'll make sure the documentation is updated in the next revision to
explain these.
I was also curious about the layout of the HFI table. I guess I can infer it
from patches 5 and 6 but if there is a picture already, I wouldn't mind. ;)
There's no picture right now, but in v3 I added a patch at the end of
the series to dump the table. I'll see what makes sense to add to
documentation.