On Wed, Jan 20, 2016 at 08:57:06PM +0100, Thomas Gleixner wrote: > > Here too, ktime_get() is daft. > > What's the problem? ktime_xxx() itself or just the clock monotonic variant? > > On 99.9999% of the platforms ktime_get_mono_fast/raw_fast is not any slower > than sched_clock(). The only case where sched_clock is faster is if your TSC > is buggered and the box switches to HPET for timekeeping.
The HPET thing, I just don't want to have to explain why this is so much more expensive on some random weird machine, esp. since it really doesn't matter.