From: Kero <kero@...>
Date: 2005-11-11T17:37:14+09:00
Subject: Re: [SORTA OT] Getting CPU usage of a process

>> > I'd like to be able to get the CPU usage of a particular process.
>> > What are my options for doing so from Ruby?
>> >
>> > And would I want to use the elapsed real cpu time?  Or the sum of the
>> > elapsed user and system cpu time?  (and then I believe I divide that
>> > by the elapsed wall clock time)
>>
>> man proc, look for "/proc/[number]/stat"
>> It contains a set of times spent by the process and its children.
>> it also contains the starttime, so this should allow you to compute "Cpu
>> usage of the process".
>
> Would I take the sum of the elapsed user and system cpu time and
> divide that by the elapsed wall clock time to get the current cpu
> percentage?

That's what I would start with.

Then you'll want to remember values of 'some time ago' so you can do the
computation 'over the last some-time', as well as 'from the start of the
process'.

+--- Kero ---------------------------------- kero@chello@nl ---+
|  The last good thing written in C++ was the Pachelbel Canon  |
|  Jerry Olson                                                 |
+--- M38c ------------ http://members.chello.nl/k.vangelder ---+