[ntp:questions] NTP + kernel frequency

Jan Ceuleers janspam.ceuleers at skynet.be
Sat Nov 10 08:45:08 UTC 2007

Per Hedeland wrote:
> On Linux, a simpler way can be to look at /proc/interrupts - e.g.
> (probably Linux-version- and possibly config-specific):
> $ (cat /proc/interrupts; sleep 10; cat /proc/interrupts) | \
>   awk '/timer/{prev=now; now=$2} END{printf "%dHz\n", int((now-prev)/10)}'

This yields 41Hz on my Via C7 machine (which has frequency scaling and 
runs a 2.6.22-based kernel) while it's idle, and a higher number (e.g. 
90Hz) while it's doing something. It yields 100Hz on a Soekris 4801 
running 2.4.31.

In other words, this method doesn't seem to be entirely reliable, 
possibly as a side effect of frequency scaling.

Cheers, Jan

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