Prevent excessive parallel jobs during compilation

The number of job slots should be fewer than the number of available logical CPUs in the system.

Signed-off-by: Jinzhe Zeng <jinzhe.zeng@rutgers.edu>

setup.py

@@ -115,7 +115,7 @@ def build_extensions(self):
                       '-DCMAKE_LIBRARY_OUTPUT_DIRECTORY_{}={}'.format(config.upper(), build_dir),
                       '-DPYTHON_EXECUTABLE:FILEPATH=' + sys.executable]
 
-        make_args = ['-j8'] if not os.environ.get('MAKEFLAGS') else []
+        make_args = ['-j' + str(min(8, len(os.sched_getaffinity(0))))] if not os.environ.get('MAKEFLAGS') else []
         if self.verbose:
             make_args.append('VERBOSE=1')