From: "David Tazartes" <davidt81@earthlink.net>
To: "'Jeremy Bopp'" <jeremy@bopp.net>, <cygwin@cygwin.com>
In-Reply-To: <4A9EB7E9.9030508@bopp.net>
Subject: RE: Simple bash script is slow to execute - appears to be time spent   starting commands like ls
Date: Wed, 2 Sep 2009 14:45:30 -0400
MIME-Version: 1.0
Content-Type: text/plain; 	charset="us-ascii"
Content-Transfer-Encoding: 7bit
Message-ID: <E1Miupq-0000A7-Kk@elasmtp-kukur.atl.sa.earthlink.net>
Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm
Precedence: bulk
Sender: cygwin-owner@cygwin.com
Mail-Followup-To: cygwin@cygwin.com

Jeremy Bopp wrote:

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.

-----

The true loop is only about 3 times slower on Cygwin than Linux. But: "true"
is a bash built-in, so there is no forking going on. So I'd argue this
absolutely shows there is a forking problem. ("time true" and "time echo hi"
both give all 0's.)

I also noticed that running "echo hi | c:\cygwin\bin\wc -l" just from cmd
seems to pause for a second or so. So perhaps I have just a problem starting
processes quickly in Vista.

cygcheck didn't reveal anything. I looked at the BLODA list and I only have
Symantec Antivirus as mentioned earlier, but I already tried disabling it to
no effect.


--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple