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Date: Wed, 02 Sep 2009 13:22:33 -0500
From: Jeremy Bopp <jeremy AT bopp DOT net>
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Subject: Re: Simple bash script is slow to execute - appears to be time spent   starting commands like ls
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David Tazartes wrote:
> Let's say we focus on the echo | cut slowness I mentioned earlier. This is
> independent of the CWD and doesn't cause the explorer.exe spike but is still
> 200 times slower on my Vista laptop than on a low-powered Linux server. If
> we correct this problem, I'm pretty confident the time per loop will go way
> down.

How about we try to boil this down a little further?  Try running the
following on your various systems and compare the results:

time for n in $(seq 1 10000); do true; done

I'm hopeful that this should help eliminate IO as a bottleneck in your
comparisons.  Maybe someone else has a better suggestion.

If you still see a difference in performance of a similar magnitude as
you do with the echo | cut case, this might argue for fork being your
problem.  I can't say whether or not what you're seeing is really
expected for fork though.  All I know is that fork is fairly slow in
Cygwin.  If it turns out that IO is the issue, I don't think I'll be
much help, not that I'm much help to begin with here. ;-)

It's also possible that you have BLODA on your laptop which could be
interfering in some way.  I think cygcheck is able to identify some of
them for you.  The problem reporting guidelines
(http://cygwin.com/problems.html) contain information for running
cygcheck which may help others identify typical problems.

-Jeremy

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