[LON-CAPA-admin] CPU Limits?

Guy Albertelli II guy at albertelli.com
Wed Aug 11 23:49:40 EDT 2004

HI Todd,

> I just did print the MSU Physics Lib sequence, which is a big
> beastie, and it took about 6 minutes.   At the same time, I was running
> "top" and noticed that none of the cpus was ever more than 50% utilized,
> and they seemed to spend most of their time at 70%+ available.  I would
> have expected at least one of the cpus to be maxed out, which would have
> greatly reduced the processing time.  Unless, of course some kind of cpu
> limits are artificially placed on the processes?

Nope lon-capa does nothing on purpose to make things slow. :-)

top by default samples every 5 seconds.

For highly transisient proccesses (like loncapa web requests, each of
which takes less than 5 seconds) this means the %CPU and overall CPU
state measurments can be incredibly inaccurate or misrepresentative.

For instance it is talking about a 5 second window, how do you
represent a process which has been running only for 1 second so far
but has been using as much CPU as it can get in that time?

Is it using 100% CPU, 20% CPU, something in between?

guy at albertelli.com  LON-CAPA Developer  0-7-3-9-

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