Performance regression with cyclic GC vs 3.13

[nascheme]

Bug report

Bug description:

While working on the free-threaded GC, I noticed this performance regression with the default build GC. Running the attached script (bm_gc_collect.py) with the main branch of Python shows much worse performance vs 3.13. I get 20.8 seconds for the main branch and 3.3 seconds for 3.13. Adding gc.disable() before calling benchmark_collection() seems to fix it.

bm_gc_collect.py.txt

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

[markshannon]

With a default build (.configure -C) I get the following:

Version	Fastest of 10
3.13	3.9s
Main	4.7s

Definitely slower, but not the dramatic slowdown you are seeing.

[nascheme]

Try removing the gc.disable() line on the first line inside benchmark_collection(). That makes "main" a lot slower for me.