docs: Correct README claim that OpenMP thread limits are process-wide#210
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mvanhorn wants to merge 1 commit into
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docs: Correct README claim that OpenMP thread limits are process-wide#210mvanhorn wants to merge 1 commit into
mvanhorn wants to merge 1 commit into
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This is already handled by the OP in #209 |
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Also mine has the benefit of not being written by an LLM sniping issues, as this appears to be. So I at least tried to make the PR accurate instead of outputting probabilistic (and in this case somewhat misleading) word salad. |
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Summary
The README's 'Limitations' section states that setting the maximum number of threads for OpenMP and BLAS libraries 'has a global effect and impacts the whole Python process' and that 'there is no thread level isolation as these libraries do not offer thread-local APIs.' Issue author itamarst demonstrated with reproducible programs (libgomp on Ubuntu, libomp via Conda-Forge) that OpenMP limits are in fact thread-specific: a limit set on the main thread does not affect a newly spawned thread's OpenMP thread count, while BLAS/OpenBLAS pthreads limits do remain process-wide. Maintainer ogrisel confirmed on 2026-06-17 that 'the documentation is wrong' and explicitly invited a PR for the fix.
Fixes #207