Using emacs' unexec to speed Python startup (was Re: [Python-Dev] Startup time) (original) (raw)

Jeff Epler jepler@unpythonic.net
Mon, 19 May 2003 07:06:36 -0500

O Sun, May 18, 2003 at 11:28:08PM -0400, Barry Warsaw wrote:

Since it looks like you implemented the meat of it as a module, I wonder if it couldn't be cleaned up (with the interrupt reset either pulled in the extension or exposed to Python) and added to Python 2.3?

First off, I sure doubt that this feature could be truly made "non-experimental" before 2.3 is released. There was one "strange bug" so far (the signal thing), though that was quickly solved (with another change to the core Python source code).

Secondly, forcing all allocations to come from the heap instead of mmap'd space may hurt performance.

Thirdly, the files implementing unexec itself, which come from fsf emacs, are covered by the GNU GPL, which I think makes them unsuitable for compiling into Python. (There's something called "dynodump" in Emacs that appears to apply to ELF binaries which bears this license:

Fourthly, we'd have to duplicate whatever machinery chooses the correct unexec implementation for the platform you're running on---there are lots to choose from: unexaix.c unexconvex.c unexenix.c unexnext.c unexw32.c unexalpha.c unexec.c unexhp9k800.c unexsni.c unexapollo.c unexelf.c unexmips.c unexsunos4.c (Of course, it's well known that only elf and win32 matter in these modern times)

I'd be excited to see "my work" in Python, though the fact of the matter is that I just tried this out because I was bored on a Sunday afternoon.

Jeff