Many Power Management Updates For The Linux 4.10 Kernel

[Azrael5]

Hi,

Our software is installed on both mid to high-end servers (1/2/4S and above) and high-end demo laptops (running Fedora, that are shipped to our sales people).
While we tested TSC heavily on servers, we usually only verify that the software more-or-less works on laptops.

That said, we rely heavily on TSC for timing calculation and throws a big-fat warning if it encounters any type of major (more than a couple 100ns) TSC clock drifts.
As far as I remember I've yet to see any clock drifts on skylake laptops w/ all the power management options enabled (I would imagine that both C1E and EIST are enabled by default).

- Gilboa

Ok in fact in the hypothesis C1E is enabled in a system where the CPU provides constant TSC, probably some problems happen and HPET should intervene based on what I've red in some web page, otherwise the system should hangs itself. However I hope to have understand wrong.

[gilboa]

Ok in fact in the hypothesis C1E is enabled in a system where the CPU provides constant TSC, probably some problems happen and HPET should intervene based on what I've red in some web page, otherwise the system should hangs itself. However I hope to have understand wrong.

I'm not sure I understand.
HPET and (C)TSC are two different things.

Plus, AFAIK at least in Linux TSC is used instead of HPET as clock source.

- Gilboa