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I am trying to get a more responsive idea of the system run queue length to see if load balancing based on the one minute load average from sysinfo() is having issues caused by the client processes perhaps looking in lockstep...

I've managed to find /proc/schedstats, and it looks to be what I'm looking for, but...

I want to make sure I base my values on the actual interval between polls of /proc/schedstat, instead of potential processing overhead (it's a shell script).

Now for the question: What is the unit of measurement used for the "timestamp" value at the top of the /proc/schedstats file? It's sure not nanoseconds, because the value is somewhere between 258 and 260 when my script loops through with a sleep 1 between loops.

Marco Bonelli
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Brian Cowan
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1 Answers1

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Inspecting kernel sources sched/stats.c shows that the timestamp field is in jiffies.

What is the unit of measurement used for the "timestamp" value at the top of the /proc/schedstats file?

It's 1/HZ second, typically with HZ=300, the unit would be 3.333 miliseconds if I'm counting right.

KamilCuk
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  • Combined with https://stackoverflow.com/questions/12480486/how-to-check-hz-in-the-terminal I now have it. It's jiffies and it's 250/sec on the hosts I'm using. – Brian Cowan Jul 22 '20 at 21:34