posixworker: avoid creating workers that end up getting no work
If `workers` (the detected or configured number of CPUs) is greater
than the number of work items, then some of the workers end up getting
0 work items. Let's not create such workers.
Differential Revision: https://phab.mercurial-scm.org/D8927
--- a/mercurial/worker.py Mon Aug 10 21:46:47 2020 -0700
+++ b/mercurial/worker.py Thu Aug 13 10:37:25 2020 -0700
@@ -211,7 +211,7 @@
parentpid = os.getpid()
pipes = []
retval = {}
- for pargs in partition(args, workers):
+ for pargs in partition(args, min(workers, len(args))):
# Every worker gets its own pipe to send results on, so we don't have to
# implement atomic writes larger than PIPE_BUF. Each forked process has
# its own pipe's descriptors in the local variables, and the parent