6 ms·

With the Intel processors suddenly being hotter with a new kernel, I'd always have a look at the cpu frequency scaling. That's where stuff changed, and the new

• throwaway984393 5y ago
  If you're not running a Thinkpad (I'm not) then there's not much that works for controlling power, fan, etc. I've tried everything I can find that works in this OS and it has almost no effect. Basic cpufreq controls work, but they only slow down the CPU, the fans keep spinning more than on the old OS. And most of the /sys/ settings that exist (like no_turbo or the power governors) simply don't work for whatever reason (and it's a Skylake CPU). I'm not surprised that there's regressions, but I am a little surprised at how poor the hardware compatibility testing is (I guess there isn't any?). The only way to know for sure if a complete system will keep working when the software changes is to test it, send test results in, look for bugs, fix those, etc. It's surprising that Linux has been developed for 30 years and there's no official test suite for hardware compatibility. All of us should be running a test suite that automatically sends reports back to the kernel devs, but for whatever reason Linus's testing model is "put out an alpha release and see if anybody complains". And there's virtually no documentation for 90% of the controls in the kernel; you have to be a kernel hacker to know what values to set on what controls and what they'll even do.
  • onli 5y ago
    I can only echo that sentiment, in a way. I was also surprised when looking at the hardware support with new kernels for my (very old) thinkpad how much just did not work anymore. IIRC, undervolting that processor had been possible before (what I looked at to make the fan quieter), but the API got removed without replacement. And the gpu could not be used for video acceleration in the browser, something that seemed to have worked when the laptop was new in Windows (at least the reviews from that time stated better support for videos with higher resolution than possible when I checked, it might also have been caused by better cpu hardware acceleration). Though some things get better with time, gpu acceleration for videos in the browser is possible now in Linux in general and works well, maybe it even works with that old gpu. For this specific issue: If the fans do not spin down when the processor clocks down the thermal control of the laptop is broken. If that worked better in earlier systems, then it wasn't BIOS controlled then but is now, or the other way around. I'd really look at whether nbfc supports it. And also at what is possible in the BIOS, a Skylake laptop with UEFI bios might have a configurable fan curve. And I'd also check what the temperature sensors output, this issue might be caused by simply more dust in the machine than it had earlier. Or, I once had the effect of my system being louder after a move, until I realized the system was equally noisy, my environment got quieter. It's easy to be wrong with those things.