Intel P-State, Schedutil Get Updated For Linux 4.12 Kernel

[phoronix]

Phoronix: Intel P-State, Schedutil Get Updated For Linux 4.12 Kernel

Intel's P-State CPU frequency scaling driver continues getting in shape with the latest mainline Linux Git code and the CPUFreq Schedutil governor also received some tuning, among other power management and APCI changes vetted for Linux 4.12...

http://www.phoronix.com/scan.php?page=news_item&px=Linux-4.12-ACPI-PM-Updates

[Azrael5]

what are all the features of 4.12 kernel release? thanks.

[tildearrow]

Is this a typo? Isn't it "ACPI"?

management and APCI changes vetted for Linux 4.12.

[kurros]

what are all the features of 4.12 kernel release? thanks.

The merge window just opened so stuff is still flowing in. Michael tends to do individual articles like this as notable stuff comes in, and an a round up once the first release candidates start.

[aufkrawall]

Hopefully my problem with schedutil and stuttering in Unigine Valley will be solved.
We desperately need a proper governor for Ryzen, with Intel you can at least rely on pstate performance to be mostly/fully on the safe side (maybe also powersave will work great with 4.11/12).

[aufkrawall]

To my knowledge, there is no difference in acpi-cpufreq governors between AMD and Intel and there is no exclusive solution like Intel's pstate for AMD on Linux.
So you either have to use ondemand, schedutil or manually enable and disable performance, which is not great. The reason why Ryzen looks great in Linux tests might be that those testloads generate a constantly high CPU usage over a longer time which is less problematic in terms of clock governors hurting performance.
Problematic are edge-cases where the governor needs to quickly adjust the clocks, e.g. games with varying load on various cores, or CPU decoding of video with varying bitrate.