Re: [PATCH v3 1/3] ACPI: CPPC: Refactor boost ratio handling
From: Mario Limonciello
Date: Wed Sep 30 2026 - 17:26:05 EST
On 9/30/26 14:37, Rafael J. Wysocki (Intel) wrote:
On Fri, Sep 25, 2026 at 4:54 PM Mario Limonciello <superm1@xxxxxxxxxx> wrote:
On 9/25/26 04:40, Christian Loehle wrote:
On 9/24/26 17:00, Mario Limonciello (AMD) wrote:
From: Mario Limonciello <mario.limonciello@xxxxxxx>
Rename amd_get_boost_ratio_numerator() to amd_get_effective_highest_perf()
to better reflect that it returns the effective highest performance value
for a CPU, accounting for preferred cores and heterogeneous topologies.
Add a new helper amd_get_boost_ratio() for doing both for boost
ratio calculations and update callers to use it.
This refactoring is needed because on some AMD systems (Zen6+),
the boost ratio should be calculated from frequency values rather than
performance values.
I think I see why you chose to implement it this way (the x86 APERF / MPERF)
issue, but I'd still prefer it to be spelled out here why this is necessary.
Do you mean in the commit message, like spin the patch? Or just in this
thread?
Not all cores will operate at the same frequency and fixed scaling
values from CPPC perf don't apply anymore.
Well, CPPC is per-CPU at least in principle, so the above doesn't
explain much TBH.
It kind of follows from the cover letter that there's something
missing in CPPC, so this is a stop-gap thing, but it would be good to
put the information from the cover letter to the changelog of this
patch.
OK; I'll respin the series with the detail in this commit message.
And yeah; this is totally stop gap to allow other development that needs this.
Once next ACPI spec is out I'll tear out the stop gap and put in the right support.