[Python-Dev] Drop support for old unsupported FreeBSD and Linux kernels?

[Victor Stinner]

I asked if we should drop support for Linux kernel 2.6. I now consider
that no, we should not. It's not worth it.

A colleague proposed to setup a RHEL 6 buildbot which would test
Python on Linux 2.6.


2018-01-19 10:26 GMT+01:00 Antoine Pitrou <solipsis at pitrou.net>:
> What is the problem with supporting Linux 2.6?

It increases the code size base. This compatibility code has to be
maintained. It would even be better to make sure that it's tested ;-)


> Do we need to rely on newer features? (which ones?)

My pull request which removed support for FreeBSD 9 and older was
quite large and so it was interesting to do it:
https://github.com/python/cpython/commit/13ff24582c99dfb439b1af7295b401415e7eb05b

According to reactions on this thread, I'm not sure anymore that
removing a few lines of C code is worth it compared to loosing support
for Linux 2.6 which seems to be important for many users.

Python has some fallback code for "recent" Linux features like
SOCK_CLOEXEC, accept4(), getrandom(), epoll_create1(), open() and
O_CLOEXEC, etc.

The worst part is that Python has to check once per process that
open() doesn't ignore O_CLOEXEC flag. It requires one extra syscall.
But well, compared to the total number of syscalls just for "python3
-c pass", this syscall is likely negligible :-)

Victor