Re: [PATCH v1 0/2] x86/smp: Fix power regression introduced by commit 96040f7273e2

[Peter Zijlstra <peterz@infradead.org>]

On Thu, May 29, 2025 at 11:38:05AM +0200, Rafael J. Wysocki wrote:

> First off, I'm not sure if all of the requisite things are ready then
> (sysfs etc.).

Pretty much everything is already running at early_initcall(). Sysfs
certainly is.

> We may end up doing this eventually, but it may not be straightforward.
> 
> More importantly, this is not a change for 6.15.y (y > 0).

Seriously, have you even tried? 

AFAICT the below is all that is needed.  That boots just fine on the one
randon system I tried, and seems to still work.

And this is plenty small enough to go into 6.15.y


diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 0835da449db8..0f25de8081af 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -814,4 +814,4 @@ static int __init cpuidle_init(void)
 
 module_param(off, int, 0444);
 module_param_string(governor, param_governor, CPUIDLE_NAME_LEN, 0444);
-core_initcall(cpuidle_init);
+early_initcall(cpuidle_init);