Feature or enhancement

Proposal:

@thesamesam pointed out to me that our GCC LTO configuration builds serially and as a single translation unit IIUC. This is the slowest configuration possible. On GCC 15, the LTO build takes 10m14.972s, in my first PR, it takes 2m28.287s. This is a multiple factor reduction in build times.

Benchmarks show basically no change in performance --- 1.004x slower on one machine, and 1.000x faster on another machine. This is basically in the realm of noise.

https://github.com/faster-cpython/benchmarking-public/tree/main/results/bm-20250407-3.14.0a6+-8891cd2

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-132257: Remove -flto-partition=none for Linux LTO builds #132258