On Fri, 2020-06-12 at 21:28 +0000, Ryan Rowe wrote: > Hello Alex, > > I’m investigating Python 3 performance issues on a Raspberry Pi Yocto > build; I appreciate any insights you can provide into the problem. > > In my investigation, I noticed that PGO was disabled in all cases due > to a small bug. I fixed it in a patch submitted to OE-Core (#139459). > Even when PGO is indeed enabled, Python 3 runs significantly slower > on Yocto-compiled Python 3.8.3 than the same version compiled on > Raspbian. > > In your patch, 0001-Makefile.pre-use-qemu-wrapper-when-gathering- > profile.patch, I see that you override the default PROFILE_TASK, > which did not explicitly specify test suites, to a command that > explicitly provides test suites. How did you decide on these tests? > The standard PGO command runs 43 tests, while you specify 7. When I > compile Python 3.8.3 on Raspbian, I see no intersection between the > 43 tests run by default and the 7 you specify. Additionally, the > default module for PROFILE is test while you use test.regrtest.
We used to run pybench and then switched to regrtest: https://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=d9f7b9d3ad44195e68b2c1b09e3eb42e623c9a20 The PROFILE_TASK value it looks like was changed recently: https://github.com/python/cpython/commit/2406672984e4c1b18629e615edad52928a72ffcc#diff-45e8b91057f0c5b60efcb5944125b585 If the performance is actually degrading, may be we should change it to something more useful. Do you know much time does the default set of tasks take to run in qemu? Thanks, Anuj > > For reference, here’s the results of a simple CPU-bound test. These > tests were run on the same Raspberry Pi 4 with same SD card. > > python3 -m timeit -r 10 --setup ' > def fib(n): > if n < 2: > return n > if n == 2: > return 1 > return fib(n - 1) + fib(n - 2) > ' '[fib(n) for n in range(20)]' > > # Yocto Python 3.8.3 > # 10 loops, best of 10: 28.9 msec per loop > # 10 loops, best of 10: 29.3 msec per loop > # 10 loops, best of 10: 27.9 msec per loop > # 10 loops, best of 10: 30.4 msec per loop > # Average result: 31.625 msec per loop > > # Raspbian Python 3.8.3 > # 50 loops, best of 10: 7.73 msec per loop > # 50 loops, best of 10: 7.72 msec per loop > # 50 loops, best of 10: 7.67 msec per loop > # 50 loops, best of 10: 7.74 msec per loop > # Average result: 7.715 msec per loop > > # Raspbian speedup: 4.09x > > Best, > Ryan Rowe >
-=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#139480): https://lists.openembedded.org/g/openembedded-core/message/139480 Mute This Topic: https://lists.openembedded.org/mt/74848490/21656 Group Owner: openembedded-core+ow...@lists.openembedded.org Unsubscribe: https://lists.openembedded.org/g/openembedded-core/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
