Google Posts Patches Allowing AMD Zen/Zen2 CPUs To Expose Power Usage On Linux Via RAPL

[phoronix]

Phoronix: Google Posts Patches Allowing AMD Zen/Zen2 CPUs To Expose Power Usage On Linux Via RAPL

One of the long sought after features for AMD Zen (and Zen 2) processors on Linux has been the ability to monitor the CPU package power consumption on Linux, similar to what's long been available for Intel CPUs on Linux and similarly for older AMD Bulldozer era CPUs with a power monitoring driver. Now on Friday evening a patch series was posted by a Google engineer to provide this long sought after functionality...

http://www.phoronix.com/scan.php?page=news_item&px=Google-RAPLs-AMD-Zen

[caligula]

Huh, only 60 lines of code. How is it possible AMD couldn't contribute any of this?

[nranger]

Huh, only 60 lines of code. How is it possible AMD couldn't contribute any of this?

Good question. Though AMD appears to have implemented the hardware/microcode in such a way to use model specific registers in a sane way that makes the support straightforward.

I'm very thankful AMD hardware is now both popular enough and open enough to have software community supported and reverse engineered. While it would be nice for RyzenMaster/Wattman type utilities to be available directly from AMD, they'd probably be tied up in packages like Radeon Software.

I've been pleasantly surprised my Ryzen 5 3500U laptop has had numerous undervolting/powermod options via open source tools like zenstates and ryzen-controller. And now that I own a Vega 56, radeon-profile seems to be just as well featured as gpu overclocking utilities in Windows.

[fuzz]

Interesting this was contributed by a Google engineer.

[discordian]

Huh, only 60 lines of code. How is it possible AMD couldn't contribute any of this?

Pretty sure Intel is at fault for not detecting and supporting amd CPUs!

[Volta]

Pretty sure Intel is at fault for not detecting and supporting AMD CPUs!

It's AMD. Maybe AMD should fix intel's frequency manager? Furthermore, intel better fix their CPUs which are spyware. Currently, intel performance is at pentium II level.

[Gusar]

zenpower could already read power consumption for Zen CPUs. This could be more accurate though, the zenpower developer reverse engineered formulas to calculate the numbers. I'll have to give this a go and compare the numbers.

[ms178]

Thankfully AMD's Zen series is popular enough that their partners also start to invest into their platform. Even though AMD could have contributed these 60 lines of code themselves, leaving such smaller tasks up to the community to tackle leaves more room for them to work on higher priority code.

[loganj]

AMD would had been so fxcked up if there was no open source community to fix their shit. so far from what i keep reading on phoronix, almost everything is solve by the community, amd fixing only some horrible bugs that prevent their CPU from booting (or was also os commutify that fix that rand bug?)

[PuckPoltergeist]

Huh, only 60 lines of code. How is it possible AMD couldn't contribute any of this?

Because of this: https://www.phoronix.com/scan.php?pa...tem&px=MTIyMzI

Now they haven't enough developers for such work.