Add -Xcpu_count=process cmdline mode to redirect os.cpu_count as os.process_cpu_count

[corona10]

Since we add the os. process_cpu_count from #109649 and -Xcpu_count= command from #109595, we can easily redirect os.cpu_count to os. process_cpu_count as we discussed at #109595 (comment)

Linked PRs

• gh-110649: Update -Xcpu_count=<n> cmdline to support process mode #110639

[vstinner]

What's the use case of this option? Would you mind to elaborate?

Why not modifying code to replace os.cpu_count() with os.process_cpu_count()?

I have doubts that this function is really needed.

cc @gpshead

[corona10]

Why not modifying code to replace os.cpu_count() with os.process_cpu_count()?

Support -X cpu_count=process: os.cpu_count() becomes an alias to os.process_cpu_count(). So legacy applications using os.cpu_count() for use case (A) (decide how many worker processes should be run) and run in read-only containers with Python 3.13 can be run with -X cpu_count=process to use the correct number of CPUs. Obviously, -X cpu_count=number would remain available if the sysadmin has a good knowledge of its system or if Python returns the wrong number of CPUs (especially in groups).

Well, I consider the case that if people want to replace it without modifying source code(3rd party library) from os.cpu_count() and os.process_cpu_count() by default.

[vstinner]

You can use export PYTHON_CPU_COUNT=$(python -c "import os; print(os.process_cpu_count())") which does the same, no?

[corona10]

Same! Then let's close it