On Mon, Oct 21, 2024 at 07:36:50PM -0700, Linus Torvalds wrote:

On Mon, 21 Oct 2024 at 03:48, Kirill A. Shutemov [off-list ref] wrote:

quoted

LAM brings own speculation issues[1] that is going to be addressed by
LASS[2]. There was a patch[3] to disable LAM until LASS is landed, but it
never got applied for some reason.

Bah., I think the reason was that nobody knew what - if any - any hardware.

I did find an Intel "Product Brief" for "Intel® Xeon® 6 processors
with E-cores" that claim both LASS and LAM, but that one puts LAM as a
"security feature", so that seems a bit confused. That's Redwood Cove
cores, I think.

I guess that should mean that Meteor Lake ("Core Ultra") should also
have it? Or is it then turned off because the E cores don't do it?

No, Meteor Lake doesn't support neither LAM nor LASS.

So far, according to SDM, it is supported by Sierra Forest (E-core based
Xeons) and Lunar Lake.

-- 
  Kiryl Shutsemau / Kirill A. Shutemov