RE: Performance regressions introduced via Revert "cpuidle: menu: Avoid discarding useful information" on 5.15 LTS

["Doug Smythies" <dsmythies@telus.net>]

On 2026.02.10 17:34 Sergey Senozhatsky wrote:
> On (26/02/10 15:24), Rafael J. Wysocki wrote:
>> On Tue, Feb 10, 2026 at 11:04 AM Sergey Senozhatsky wrote:
>>> On (26/02/10 17:33), Xueqin Luo wrote:
>>>>
>>>> In addition to the cpuidle statistics, measured system idle power is
>>>> about 2W higher when this commit is applied.
>>>>
>>>
>>> We also noticed shorted battery life on some of the affected laptops.
>> 
>> Was the difference significant?
>
> I think I saw up to "5.16% regression in perf.minutes_battery_life"

Note: I get a fair bit of noise on my idle tests of recent.

For what it's worth: On my test computer I got:

kernel 6.19-rc8 and with reapply.

Processor: Intel(R) Core(TM) i5-10600K CPU @ 4.10GHz, 6 cores 12 CPUs.

CPU frequency scaling driver: intel_pstate.
CPU frequency scaling governor: powersave.
HWP: enabled.
idle governor menu.

Git Branch "doug"

3856f38e5bb9 (HEAD -> doug) Reapply "cpuidle: menu: Avoid discarding useful information"
18f7fcd5e69a (tag: v6.19-rc8) Linux 6.19-rc8

Processor Package Power:

average reapply: 140 minutes: 1.783028571
average rc8: 512 minutes: 1.656212891
7.65% more power