Allow "-j0" as an argument to regrtest, to automatically select an
appropriate number of parallel workers.
diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py
index 1e72f80..a00f15a 100755
--- a/Lib/test/regrtest.py
+++ b/Lib/test/regrtest.py
@@ -374,6 +374,13 @@
forever = True
elif o in ('-j', '--multiprocess'):
use_mp = int(a)
+ if use_mp <= 0:
+ try:
+ import multiprocessing
+ # Use all cores + extras for tests that like to sleep
+ use_mp = 2 + multiprocessing.cpu_count()
+ except (ImportError, NotImplementedError):
+ use_mp = 3
elif o == '--header':
header = True
elif o == '--slaveargs':