Improve _Py_yield to use light weight cpu instruction
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@corona10 is already working on this.
Since Feb 8, 2026.
interpreter-core
performance
topic-free-threading
type-feature
- Dominant language
- Python
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- 77.2k
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Description
Proposal:
_Py_yield() currently relies on sched_yield()/SwitchToThread(), which are OS-level syscalls. We can replace these with lightweight CPU pause instructions (x86 PAUSE, AArch64 WFE, etc.) as CPython's bundled mimalloc already does in mi_atomic_yield(): https://github.com/python/cpython/blob/e682141c495c2e52368c4341ae54eea041070356/Include/internal/mimalloc/mimalloc/atomic.h#L323-L389
Has this already been discussed elsewhere?
No response given
Links to previous discussion of this feature:
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Linked PRs
- gh-144587
- gh-149784
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