lkml.org 
[lkml]   [2022]   [Sep]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] ACPI: processor_idle: Skip dummy wait for processors based on the Zen microarchitecture
On Wed, Sep 21, 2022 at 09:48:13PM +0200, Borislav Petkov wrote:
> On Wed, Sep 21, 2022 at 05:00:35PM +0200, Peter Zijlstra wrote:
> > On Wed, Sep 21, 2022 at 12:06:38PM +0530, K Prateek Nayak wrote:
> > > Processors based on the Zen microarchitecture support IOPORT based deeper
> > > C-states.
> >
> > I've just gotta ask; why the heck are you using IO port based idle
> > states in 2022 ?!?! You have have MWAIT, right?
>
> They have both. And both is Intel technology. And as I'm sure you
> know AMD can't do their own thing - they kinda have to follow Intel.
> Unfortunately.
>
> Are you saying modern Intel chipsets don't do IO-based C-states anymore?

I've no idea what they do, but Linux exclusively uses MWAIT on Intel as
per intel_idle.c.

MWAIT also cuts down on IPIs because it wakes from the TIF write.

\
 
 \ /
  Last update: 2022-09-22 10:18    [W:0.081 / U:0.480 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site