dtrace users opinion solicited (timestamps)

Andriy Gapon avg at freebsd.org
Fri Jul 10 12:27:20 UTC 2009

on 10/07/2009 01:02 Andrew Brampton said the following:
> According to wikipedia newer Intel processors have a constant rate TSC
> whos freq does not change. If this features is available on most
> processors today, then I am happy to stick with option 1.
> Another problem with this is that on a multicore machine each core may
> have different TSC values. Has anyone thought how to address this
> issue? Could we calculate the offset of each core from core0, and then
> ensure the offset is applied to the tsc value when it is needed?

Yes. The actual code accounts for inter-CPU/core TSC skew.

Andriy Gapon

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