[Coin-discuss] user time vs. system time

[Brady Hunsaker]

I'm teaching a computational optimization class, and I realized I need 
to talk about measuring time correctly.

What I have always done, and what CoinCpuTime does, is to measure only 
the user time.  But I realized that I don't have a good explanation for 
why system time is excluded.  I couldn't find one in a quick web search 
either.

Is the idea that system time depends on kernel code rather than the user 
code, so we should ignore it?  But why is that?  Is it ever appropriate 
to include system time in computational results?  (If so, we should add 
this capability to CoinTime.)

Thanks,
Brady