The reuseport_lb_test regression test is consuming a lot of sockets, but once ended the system will kept all those sockets open waiting for the TIME_WAIT.
And if another tests, consuming a lot of sockets too is started just after, this could reach the system limit and fail.
Patch and review here:
A commit references this bug:
Date: Fri Sep 25 16:02:13 UTC 2020
New revision: 366159
Enable SO_LINGER to the so_reuseport_lb_test regression tests, preventing
many sockets in TIME_WAIT state at the end of the test.
Reviewed by: markj
Approved by: markj
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D26549