Skip test_highly_nested_objects_decoding during the PGO profile task.#151460
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Since the recursion guard tracks real C-stack bounds (pythongh-91079), this test asserts that 500k nesting levels overflow the stack margin. On a 64 MiB stack (some Nix build envs use one that large), the optimized interpreter uses ~160 bytes/level (raises at ~420k levels) so the assertion holds with only ~16% margin; the PGO *instrumented* stage inlines less, its per-level scanner frames are smaller, and the 500k-deep decode completes -- "RecursionError not raised" fails the profile run and aborts `make profile-opt`. Upstream's skip_if_unlimited_stack_size (pythongh-143460) only covers RLIM_INFINITY, not large-finite stacks like ours. We could also keep playing whack a mole and raise the 500k to a much larger number... but there's little value in PGO training on this test anyways.
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Thanks @gpshead for the PR 🌮🎉.. I'm working now to backport this PR to: 3.14, 3.15. |
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GH-151468 is a backport of this pull request to the 3.15 branch. |
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GH-151469 is a backport of this pull request to the 3.14 branch. |
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One line change to disable test_json.test_highly_nested_objects_decoding during PGO training.
Since the recursion guard tracks real C-stack bounds (gh-91079), this test asserts that 500k nesting levels overflow the stack margin. On a 64 MiB stack (some Nix build envs use one that large), the optimized interpreter uses ~160 bytes/level (raises at ~420k levels) so the assertion holds with only ~16% margin; the PGO instrumented stage inlines less, its per-level scanner frames are smaller, and the 500k-deep decode completes -- "RecursionError not raised" fails the profile run and aborts
make profile-opt. Upstream's skip_if_unlimited_stack_size (gh-143460) only covers RLIM_INFINITY, not large-finite stacks like ours.We could also keep playing whack a mole and raise the 500k to a much larger number... but there's little value in PGO training on this test anyways.