Linux follows Windows and makes a CPU feature requirement mandatory

isnt the tsc at the clockspeed and not a constant time?? i thought the value of the other timers (e.g. lapic?) was u can calibrate them so u can be somewhat sure the timer on 1 system is same speed as timer on the other system, e.g. both 100 or 1000hz or so.

how does this work with TSC are modern ones constant time somehow?

mostly i know timers are weird allround. lapic in bare metal linux behaves vastly different from lapic in linux KVM for example. i can imagine similar stuff for the others timers (no vmx/svm timers that are compatible with virtualization?)