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GeezerVison is showing github.com — GH-126910: Revert "Make `_Py_get_machine_stack_pointer` return the stack pointer (#147945)" by encukou · Pull Request #147994 · python/cpython

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@encukou

@encukou encukou commented Apr 2, 2026 •
edited by bedevere-app Bot
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This reverts commit 255026d.

I suspect this commit broke a tier-1 buildbot; I'll use this PR to confirm.
Per PEP-11, any breakage should be fixed or reverted immediately.

  • Issue: Supporting stack unwinding in the JIT compiler #126910

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@encukou
Revert "pythonGH-126910: Make _Py_get_machine_stack_pointer return …
6803150 
…the stack pointer (python#147945)"

This reverts commit 255026d.
@bedevere-app bedevere-app Bot mentioned this pull request Apr 2, 2026
Supporting stack unwinding in the JIT compiler #126910
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@encukou

encukou commented Apr 2, 2026

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!buildbot AMD64.CentOS9.NoGIL
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@bedevere-bot

bedevere-bot commented Apr 2, 2026

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🤖 New build scheduled with the buildbot fleet by @encukou for commit 6803150 🤖

Results will be shown at:

https://buildbot.python.org/all/#/grid?branch=refs%2Fpull%2F147994%2Fmerge

The command will test the builders whose names match following regular expression: AMD64.CentOS9.NoGIL

The builders matched are:

  • AMD64 CentOS9 NoGIL Refleaks PR
  • AMD64 CentOS9 NoGIL PR
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@encukou
encukou marked this pull request as ready for review April 2, 2026 08:35
@encukou
encukou requested review from FFY00, ZeroIntensity, brandtbucher, diegorusso, ericsnowcurrently, markshannon and savannahostrowski as code owners April 2, 2026 08:35
@bedevere-app bedevere-app Bot added the awaiting core review label Apr 2, 2026
@encukou

encukou commented Apr 2, 2026

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@Fidget-Spinner @markshannon Are you able to investigate/fix this today?
If not, let's revert so the buildbot can catch other issues, and re-apply later.
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@markshannon

markshannon commented Apr 2, 2026 •
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I can't reproduce the failure on either fedora x86-64 or ubuntu Aarch64.

Note, that #147945 doesn't change the way frames are laid out or any aspect of the program, except:

  • How JIT frames are laid out (there is no JIT active on the failing buildbot)
  • How deep the stack can go before a RecursionError is raised.

Does CentOS have a glibc missing a way to tell the stack size?

I want to try increasing the estimated stack size a bit, as I suspect the combination of debug build, no-gil and perf trampolines is causing the stack to grow very fast.
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@markshannon

markshannon commented Apr 2, 2026

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#148002
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@markshannon

markshannon commented Apr 2, 2026

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It doesn't look like it is a stack issue.

It looks like py_trampoline_evaluator isn't calling the generated function for the code object. I don't know why.
It looks like whatever the problem is is being swallowed, not reported:
https://github.com/python/cpython/blob/main/Python/perf_trampoline.c#L452

@pablogsal any idea why py_trampoline_evaluator is not working?
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@markshannon markshannon added the skip news label Apr 2, 2026
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markshannon approved these changes Apr 2, 2026
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@encukou go ahead with the revert. I doubt this will be fixed before the weekend

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@bedevere-app bedevere-app Bot added awaiting merge and removed awaiting core review labels Apr 2, 2026
@encukou
encukou merged commit 9b08f8c into python:main Apr 2, 2026
83 of 84 checks passed

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@bedevere-app bedevere-app Bot removed the awaiting merge label Apr 2, 2026
@encukou

encukou commented Apr 2, 2026

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I also can't reproduce on a centos container (on a Fedora kernel).
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@encukou
encukou deleted the revert-255026d branch April 2, 2026 14:53
@pablogsal pablogsal mentioned this pull request Apr 4, 2026
gh-130273: Fix traceback color output with unicode characters #142529
Merged
ljfp pushed a commit to ljfp/cpython that referenced this pull request Apr 25, 2026
@encukou @ljfp
pythonGH-126910: Revert "Make _Py_get_machine_stack_pointer return …
eb941df 
…the stack pointer (python#147945)" (pythonGH-147994)

Revert "pythonGH-126910: Make `_Py_get_machine_stack_pointer` return the stack pointer (python#147945)"

This reverts commit 255026d,
which broke a tier-1 buildbot.
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@markshannon markshannon markshannon approved these changes
@ericsnowcurrently ericsnowcurrently Awaiting requested review from ericsnowcurrently ericsnowcurrently is a code owner
@ZeroIntensity ZeroIntensity Awaiting requested review from ZeroIntensity ZeroIntensity is a code owner
@FFY00 FFY00 Awaiting requested review from FFY00 FFY00 is a code owner
@brandtbucher brandtbucher Awaiting requested review from brandtbucher brandtbucher is a code owner
@savannahostrowski savannahostrowski Awaiting requested review from savannahostrowski
@diegorusso diegorusso Awaiting requested review from diegorusso diegorusso is a code owner

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@encukou @bedevere-bot @markshannon
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