Graphing CPU Usage on Freebsd with SMP.

[gninja]

Having some issues getting my cpu usage graphs to come out right on freebsd boxes (4.10).

Was getting gaps under light load on a 2cpu box, figured that it was reporting '100%' cpu usage as 50% due to the dual cpus, switched my ds max to 200, added a cdef to divide by two, and it worked, sort of. Started getting gaps under heavier load, did some digging, turns out these boxes have hyperthreading enabled, so I figured, 2*2 = 4!

Switched my ds max to 400, changed my cdef to a divide by four.

Today I end up with a box with some runaway processes, pegging the cpu at 100%. Only, my graph shows it stuck around 62%.

I'm not sure what would cause that value. Is this a bug in freebsd or net-snmp? (100% on my linux boxes shows up as 100%)...

[asdfasdf]

freebsd shows 128 ticks per second per cpu, therefore you need to have a ds max value of 4*128=512, and instead of /4 you need to /5.12