On 9/22/22 10:48, Limonciello, Mario wrote:
- The title says to limit it to old intel systems, but nothing about this actually enforces that.
It actually is limited to all Intel systems, but effectively won't be used on anything but new ones because of intel_idle.
As an idea for #2 you could check for CONFIG_INTEL_IDLE in the Intel case and if it's not defined show a pr_notice_once() type of message trying to tell people to use Intel Idle instead for better performance.
What does that have to do with *this* patch, though?
If you've got CONFIG_INTEL_IDLE disabled, you'll be slow before this patch. You'll also be slow after this patch. It's entirely orthogonal.
I can add a "Practically" to the subject so folks don't confuse it with some hard limit that is being enforced:
ACPI: processor idle: Practically limit "Dummy wait" workaround to old Intel systems
BTW, is there seriously a strong technical reason that AMD systems are still using this code? Or is it pure inertia?