[Python-Dev] _sre as part of python.dll

Guido van Rossum guido@python.org
Thu, 08 Aug 2002 16:49:12 -0400

> > But is the startup time of apps that use a lot of stuff the most
> > important thing?  I'd say that the startup time of apps that *don't*
> > use a lot of stuff is more important.  I'm not sure that making the
> > binary bigger doesn't slow it down.
> I'm pretty sure that it doesn't. On Unix, the system performs a
> copy-on-write mmap of the executable. No disk access is done until
> page faults trigger a disk read. I believe Windows uses a similar
> mechanism. The size of the executable is irrelevant (if you have no
> relocations); only the part of the executable that is used matters.
> On the other hand, on my Linux installation, importing a module costs
> 35 system calls if the module is not found, and no PYTHONPATH is set;
> every directory in PYTHONPATH adds four additional system calls.
> > Yes, please.  We switched to building almost all extensions as shared
> > libs when we switched away from Modules/Setup to setup.py.
> For modules that require configuration, this was a good thing - now
> setup.py will autoconfigure them. For modules that require no
> additional libraries, I hope that this decision will be reverted some
> day.

If other people feel the same way, I won't stop progress here.  But I
find startup time a rather uninteresting detail, and everything else
being the same I would personally prefer to keep the status quo: not
because it's better, but because it's the status quo.  Why churn?

--Guido van Rossum (home page: http://www.python.org/~guido/)