Re: [PATCH V2] x86/mce: Serialize sysfs controls against CPU hotplug

[Borislav Petkov]

On Thu, Oct 29, 2026 at 12:56:36PM -0400, Yazen Ghannam wrote:
> The diff below fixes both.

No, we've been trying hard to fix this shit and I already told tglx offlist,
I am that >.< close from simply disabling any hotplug operations as long as
someone touches those sysfs files.

There is no good reason to be toggling those continuously and f*ck around with
CPU hotplug at the same time. You do those configurations and then done. Not
whack them all the time.

So this code needs to be simplified - not made an even crazier and
unmaintainable mess.

So, I don't know yet in detail how we are going to query the hotplug core
whether operations are in progress but once we do, those sysfs helpers should
simply do:

	if (hotplug_operations_in_progress)
		return -ECOMEBACKLATER;

And that hotplug_operations_in_progress should include partial hotplug. I.e.,
has someone done partial hotplug? If so, error too.

And that's it.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette