Serhiy Storchaka: "I prefer to delay pushing the patch until we prove its usefulness, because the cost of this change is not zero. Is it a stopper for issue29465?"

Ok. No, it's not a blocker for my issue #29465.

About usefulness, I'm curious of the performance impact on this patch on top of the issue #29465. I tried to run a benchmark, but my tooling only works well with a single patch, not with two patches, and one based on the other. Moreover, our patches are in conflict.

So it seems like the issue #29465 makes Python faster and uses less stack memory, I suggest to first focus on that one, and then rebase your patch on top of that. What do you think?