mod_wsgi Daemon Mode: "Enable threads support in APR"?

[Steve Williams]

I'd like to run mod_wsgi in "daemon mode."  I read in the docs:

http://code.google.com/p/modwsgi/

>Daemon mode of mod_wsgi will however only be available on Apache 2.0 
>or 2.2 running on UNIX, and only when the Apache runtime library 
>underlying Apache has been compiled with support for threading.

When I make config in apache-2.2.15_9, I see the option "Enable 
threads support in APR."  Is that what the mod_wsgi doc is referring to?

Can anyone point me to discussion or documentation of the pros and 
cons of that config option?

Thanks!