[ic] Interchange and threaded Perl

Henry Hartley henryhartley at westat.com
Mon Jun 6 16:18:21 EDT 2005

On: Mon, June 06, 2005 12:48 PM, Mike Heins said:
>> Quoting Kaare Rasmussen (kar at kakidata.dk):
>> > 
>> > > It's a shame not only because of Interchange, but because
>> > > *every* Perl program runs 15-30% slower and because about .01%
>> > > of code uses the features.
>> > 
>> > Where do you have those numbers from?
>> > 
>> > It's not that I doubt them. I just would like to see if they've
>> > tested various applications to see where the penalty is biggest.
>> Just benchmarks of running ab against Interchange and test code
>> against a threaded Perl. I had an email discussion with the Debian
>> Perl port maintainer, and he confirmed the slowdown.
>> The more subroutine calls you have, the worse it will be, so in
>> all liklihood object-oriented packages with lots of method-based
>> accessors will get hit hardest.

Can you give some idea of how big a hit we're talking about?  In my
case, I've got a Fedora Core 3 web server and only use Interchange on
one site.  That site is small and very (VERY) low volume and I'd be
willing to put up with it not being particularly fast.  It would
certainly make my life a lot easier if I had the option to use the
threaded perl that I get with FC3.  Yes, I can (and did) replace the
perl with a non-threaded perl.  Then I had to replace some of the
modules with non-threaded versions.  Keeping track of that is a pain.
Not the end of the world but certainly I'd be willing to put up with a
little slowdown on this one site to avoid that.  Or would a threaded
perl make it really, REALLY slow?  Alternatively, I could switch distros
but that seems like even more work that what I've already done.

Would it be possible, instead of requiring non-threaded perl, to change
the installation of Interchange to warn (even warn strongly and require
a switch) before installing in a threaded perl environment?  Or is that
more trouble than what I go through to manage my Perl?


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