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Posted by f311a 21 hours ago

Python's experimental JIT to be removed(lwn.net)
495 points | 267 commentspage 3
niltecedu 15 hours ago|
ffffffff.... damnit I love python but why is it so difficult like this. JIT would have been so perfect so the language, increasingly overtime with AI code coming through I am not sure not focusing on making the performance better is going to be better for longer term. Even though a lot of the other operations done in python are done faster in libraries I would still like faster startup times, or faster loops.
manvillej 16 hours ago||
This seems to be all about drift from the main implementation of Cpython.

If JIT is different enough in maintenance, security best practices, and consumer use, we don’t have two compilers, we have two different languages.

And that’s the crux of it.

callamdelaney 13 hours ago||
Python needs less features, not more.
O5vYtytb 19 hours ago||
What a shame. The alternative is CinderX? It's slower unless you stick to "Static Python" which is not most python code in the wild.
yje07039 18 hours ago||
Hope the copy-and-patch work gets a proper write-up before it’s removed... The technique is interesting well beyond CPython.
Krishansubudhi 20 hours ago||
I hope it does not lead to performance issues later. Python is already famous for being slower than compiled languages.
FranOntanaya 20 hours ago||
Being slower than a compiled language is not saying much for an interpreted language. But it's slower than PHP which is a closer comparison, and PHP has had JIT for six years now.
pansa2 19 hours ago|||
Ruby has the reputation of being a very slow language, but Python has been slower still since Ruby jumped ahead with version 1.9, almost 20 years ago. Ruby also has had far more success with JIT compilers than Python has.
chao- 19 hours ago||
>Ruby also has had far more success with JIT compilers than Python has.

Ruby is on its third (I think?) JIT now? I'm a little surprised, given Ruby's reputation as a wacky "anything goes" language with a very complex grammar, and it makes me wonder why that is? Does it have to do with the design of the runtime itself more than the language semantics? Or is it more incidental, e.g. many popular ibs are C wrappers, already generates bytecode files, and so on.

byroot 16 hours ago|||
The difference is that Ruby follow the BDFL model, and Ruby's BDFL was willing to allow people to experiment with in-tree development of JITs.

If the Python steering committee isn't willing to do the same, they'll probably won't get a working JIT any time soon. Developing a JIT externally, or even from a branch, is just too hard.

samus 18 hours ago|||
Getting a JIT right is hard work because time spent by the JIT is time not spent doing actual work, and finding the correct tradeoffs is very much an empirical problem.
skeledrew 18 hours ago||||
And PHP is quite the hot mess. Always has been, really. See the security issues over the years, including the most recent for example. Meanwhile I've never seen any serious issues for Python that's triggered mass required fixing. There's something to be said for moving carefully and ensuring things aren't broken to the best of one's ability, which is the SC's purpose.
pjmlp 17 hours ago||
https://app.opencve.io/cve/?product=python&vendor=python
skeledrew 12 hours ago||
Are you helping me to prove my point? I see 156 results, with 1 in 2023 and the rest before that. Meanwhile there are 801 results with at least a dozen in 2026 for PHP[0], and we still have 2 more months to go.

[0] https://app.opencve.io/cve/?vendor=php

pjmlp 11 hours ago||
Hardly, one CVE is enough.
skeledrew 2 hours ago||
Not at all. I specifically stated "serious issues for Python that's triggered mass required fixing", ie. it was so bad that there were public notices for users to update ASAP. The closest thing I can find is CVE-2022-34265, and that's in Django, not Python itself.
pjmlp 56 minutes ago||
Python is hardly used at PHP scale for Web development.
mahboi 9 hours ago|||
and the biggest one, JS
yxhuvud 12 hours ago||
It is also slower than any other interpreted dynamic language in wide use.
pjmlp 18 hours ago||
This is why we cannot have nice things.

Why had Python to succeed to Lisp in the AI wave? (rhetoric question)

Since PyPy and GraalPy will never get the love they deserve, I guess there is hope that Julia, Mojo, and the whole Rewrite in Go/Rust keep pushing along then.

shevy-java 14 hours ago||
Python is no doubt a successful language. But, boy - this level of bureaucracy is annoying to no ends. Do people feel eager to propose a PEP? There are so many more enjoyable things to do in one's short life ...
nromiun 18 hours ago||
I don't know why they don't just adopt Pypy as a faster Python implementation. Just let CPython develop slowly as the reference and give support to Pypy. It is already much faster than CPython.
anthk 20 hours ago|
The Rust based Python3 port can keep it and it can still be far more secure than CPython. Not everything it's JIT'ted on RustPython, it's ondemand per function, you have to enable it explicitly.
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