Bug 476968 – sys-kernel/gentoo-sources-3.10.1: CPU governors conservative ondemand not available

• Product: Gentoo Linux
• Status: RESOLVED INVALID

[Description am1 2013-07-15 20:17:58 UTC]

Heya,

after installing 3.10.0 and now 3.10.1 the CPU-governors "conservative" and "ondemand" doesn't appear in "/sys/devices/system/cpu/cpu*/cpufreq/scaling_available_governors". CPUs get autoforced to "powersave".

Seems to be some bugs, because in .config all governors are selected.

Reproducible: Always

Steps to Reproduce:
1. make menuconfig && select all CPU-governors
2. boot into new kernel
3. checkout your currently used/available CPU-governors in "/sys/devices/system/cpu/cpu*/cpufreq/scaling_available_governors"

[Comment 1 Ben Kohler 2013-07-15 20:25:00 UTC]

This is normal if you are using the intel_pstates scaling driver.  It will show powersave as the active governor, but it will actually scale up properly under load.  You can check on all of this with "cpufreq-info" from sys-power/cpufrequtils.

[Comment 2 am1 2013-07-15 20:30:22 UTC]

For me this isn't normal, because intel_pstate are also enabled in 3.9.9 and there my 4 cpu's get handled by "conservative".

Now all of these gets fired up to 3.57 Ghz, all 4. It heat-up my ThinkPad and run at fullpower the whole time. Selected governor is "powersave" - shouldn't it decrease to the lowest available?

This isn't really good or???! -.-

Something should get fixed like to the previous 3.9.9.

If you need something, let me know. :)

[Comment 3 Ben Kohler 2013-07-15 20:37:36 UTC]

The behavior of powersave/conservative/etc are different under intel_pstates than they were with other drivers like acpi_pstates, don't expect them to work exactly the same.

The scaling to full power may be due to enabling CONFIG_NO_HZ_FULL aka "Full dynticks system", try using CONFIG_NO_HZ_IDLE aka "Idle dynticks system" instead.   Full dynticks is new to 3.10 and I don't think it works properly with the intel_pstates driver yet.

[Comment 4 am1 2013-07-15 20:51:04 UTC]

(In reply to Ben Kohler from comment #3)
Ok with CONFIG_NO_HZ_IDLE it is much better than before. The CPUs gets throttled. ;)

I think it is too early to use 3.10 and above, or?

[Comment 5 Jeroen Roovers (RETIRED) 2013-07-15 21:08:11 UTC]

I see no bug here.