rms@gubba.SPDCC.COM (Rich Sands) (06/14/88)
I'm trying to build some performance monitoring tools under Sys V R2 on
a PC6300 PLUS. I came across the sysinfo data structure found in
/usr/include/sys/sysinfo.h, which has a number of counters that seem to
be incrememted when various interesting kernel events take place.
Questions:
1) Am I right in guessing that at each clock tick one of the eight
counters in the cpu[] array and wait[] array is incremented, depending
on the cpu or wait state at the time of the clock interrupt?
2) What is the event that triggers incrementing of the following
counters: swapin, swapout, bswapin, bswapout, runque, runocc, swpque,
swpocc, dirblk, rcvint, xmtint, mdmint? The others I think I've figured
out. In particular, how can I use the changing values of runque and
runocc to generate the load average?
3) What is the difference between the syswait structure and the wait[]
array in the sysinfo structure?
4) What is getting tallied in the syserr structure?
Thanks in advance,
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