"jobs = 0" is twice slower than "jobs = 1" when running via "pre-commit"

[simon-liebehenschel]

Bug description

"jobs = 0" is twice slower than "jobs = 1"

(57 seconds VS 30 seconds)

Commands

Set jobs = 0:

# Use multiple processes to speed up Pylint. Specifying 0 will auto-detect the
# number of processors available to use, and will cap the count on Windows to
# avoid hangs.
jobs = 0

Result:

time pre-commit run pylint --all-files
pylint...................................................................Passed

real    0m57,423s
user    3m9,893s
sys     0m5,131s

Set jobs = 1:

# Use multiple processes to speed up Pylint. Specifying 0 will auto-detect the
# number of processors available to use, and will cap the count on Windows to
# avoid hangs.
jobs = 1

Result:

time pre-commit run pylint --all-files
pylint...................................................................Passed

real    0m30,851s
user    1m39,719s
sys     0m2,460s

Expected behavior

"jobs = 0" and "jobs = 1" must have the same execution time when running via "pre-commit"

As the documentation says, jobs can not be < 1, so if I set jobs = 0, then pylint must automatically set jobs amount >=1. In other words, speed with "jobs = 0" can not be lower than "jobs = 1".

Pylint version

pylint 2.14.5
astroid 2.11.7
Python 3.10.4 (main, Jun 29 2022, 12:14:53) [GCC 11.2.0]

OS / Environment

Lubuntu 22.04

[Pierre-Sassoulas]

Duplicate of #2525