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gh-121313: multiprocessing: change connection buffer size to 64KiB - #123559
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Really small nitpick. But otherwise LGTM.
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
picnixz
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vstinner
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Co-authored-by: Victor Stinner <vstinner@python.org>
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I tested this PR on Windows but no speedup. It is because Windows can read whole remaining data at once via this function. cpython/Lib/multiprocessing/connection.py Line 350 in 7dc489b |
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Windows:
Current buffer size is 8KiB since multiprocessing is introduced.
It seems small for recent Python usages.
e711caf#diff-2c54a007d7fe1d9ac5ca008fe2d054394c39a4f521eea2cb580101a284d7b7ecR28
macOS/BSD:
They use 64KiB buffer for pipes. Current 16 pages (256KiB) buffer makes ~10% slowdown compared to 64KiB on M1 mac.
Linux:
I don't have 16k/64k page Linux. But when I change the pipe buffer size via fcntl, 256KiB buffer doesn't make notable performance benefit.
64KiB seems good default buffer size.
If it is not suitable, user can try other size by changing
multiprocessing.connection.BUFSIZE.