top linux command reporting wrong values

Vikneels · 05-21-2009, 03:50 PM

Hi,

I was running some test and i happened to find that even though the cpus are handling the intterupts and the number of interrupts on each cpu is 1000/sec, the top command shows all the cpus are idle. What will be the reason for this?

Also, in NFS time out happens sometime in my machine. Will that be a reason for wrong cpu utilization number.

thanks,
Vikram

syg00 · 05-21-2009, 06:47 PM

Top merely reports what is accumulated in /proc.
If a CPU is in interrupt context, it is not going to be sampled. Hence the usage is "lost" - as is the time for running the sampling code I suspect, but I haven't checked.

I would think the NFS timeouts are unrelated.