Bug 218492 - poor CPU performance due to wrong frequency scaling
Summary: poor CPU performance due to wrong frequency scaling
Status: REOPENED
Alias: None
Product: Power Management
Classification: Unclassified
Component: intel_pstate (show other bugs)
Hardware: Intel Linux
: P3 normal
Assignee: Kristen
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-02-14 10:37 UTC by Lukasz Wieczorek
Modified: 2024-02-23 19:55 UTC (History)
2 users (show)

See Also:
Kernel Version:
Subsystem:
Regression: No
Bisected commit-id:


Attachments

Description Lukasz Wieczorek 2024-02-14 10:37:04 UTC
Hello,

being full of doubts if I report the problem in a right category, but perhaps you are able to narrow this down or suggest a better place.

I'm using openSUSE Tumbleweed 20240212, with 6.7.4-1-default kernel with old HP laptop with Intel(R) Core(TM) i5-5300U CPU @ 2.30GHz. I'm not sure if the problem existed right from the fresh installation a few years ago, anyway I was suffering poor performance on the CPU. I tried to play with different governors but for some reasons despite using 'performance' governor the clock never went above 2,2GHz.

I started reading about intel p-state and I discovered that after reboot:
/usr/bin/echo 1 >  /sys/devices/system/cpu/intel_pstate/no_turbo
suddenly allows 2,3GHz clock and after that:
/usr/bin/echo 0 >  /sys/devices/system/cpu/intel_pstate/no_turbo
give a full throttle with clock boosts etc etc up to 2,9GHz.

however all the time /sys/devices/system/cpu/intel_pstate/ shows passive state.

I'm looking for the real cause here for the by default poor performance, is it p-state module problem, kernel is missing any config option to initiate properly the CPU boost or any other reasons.

Attaching current kernel options.

Any more experienced user hint is much appreciated.
Comment 1 Artem S. Tashkinov 2024-02-21 07:56:52 UTC
Try booting with intel_pstate=disable and check your max frequencies/boost availability.

If it's still not there, please try updating your BIOS to the latest version and test again.
Comment 2 Lukasz Wieczorek 2024-02-23 08:25:24 UTC
Hello,

BIOS was already in the latest version, yet your suggestion was what I needed: I removed all systemd services related to this, blocked this module and after a few days of testing I can say it works perfect again: both on AC and without AC.

Thank you!

Luk
Comment 3 Artem S. Tashkinov 2024-02-23 09:17:56 UTC
CC'ing Srinivas Pandruvada because it still looks like a bug worth addressing.
Comment 4 Artem S. Tashkinov 2024-02-23 09:18:23 UTC
And Rafael J. Wysocki for good measure.
Comment 5 Lukasz Wieczorek 2024-02-23 09:21:45 UTC
If you need any additional logs or testing, let me know.

Luk
Comment 6 Srinivas Pandruvada 2024-02-23 15:22:47 UTC
You mean if you do these steps, you don't have any issue?

/usr/bin/echo 1 >  /sys/devices/system/cpu/intel_pstate/no_turbo
suddenly allows 2,3GHz clock and after that:
/usr/bin/echo 0 >  /sys/devices/system/cpu/intel_pstate/no_turbo
give a full throttle with clock boosts etc etc up to 2,9GHz.
Comment 7 Lukasz Wieczorek 2024-02-23 19:55:42 UTC
Now with pstate disabled I do not do any tricks on /sys or loading CPU governor in other words disabling this pstate cured my laptop's performance. Not sure if it makes any sense from your perspective.

Luk

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