[gambit-list] Running times: real vs. CPU

Taylor Venable taylor at metasyntax.net
Sun Apr 26 12:09:15 EDT 2009


On Sun, Apr 26, 2009 at 10:10:39AM -0400, Marc Feeley wrote:
> This sounds like more than one UNIX process is running.  Can you try  
> running "top" while you execute ./a.out ?

First of all, I'm on a system that looks like it has two CPUs (I have
one of those Pentium 4 processors with hyper-threading).

Looking at `top` and comparing the three aforementioned Scheme
implementations, I see some interesting results: whereas Chicken and
MzScheme both stay in the process running state (onproc), Gambit
frequently does a nanosleep which forces it to go into the
ready-to-run state (run) before it can execute again.  The Chicken and
MzScheme impls will use the CPU that they're running on 100% but it's
about 40% - 60% idle when running the Gambit version.

-- 
Taylor Christopher Venable
http://real.metasyntax.net:2357/



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