test-poll: High failure rate on multi-core FreeBSD guest

[Andrea Bolognani]

Hi,

the test-poll test seems to have a very high failure rate on a
multi-core FreeBSD guest:

  $ for i in $(seq 1 10000); do
  >   ./tests/test-poll >/dev/null 2>&1
  >   echo $?
  > done >test-poll.rc
  $ grep -c '.*' test-poll.rc
  10000
  $ grep -c '^0$' test-poll.rc
  5
  $ grep -c '^1$' test-poll.rc
  50
  $ grep -c '^2$' test-poll.rc
  9945

If I configure the guest to only have a single vCPU rather than
two, then the test succeeds every single time.

Daniel recently had to fix one of libvirt's own test cases[1],
which similarly started failing on FreeBSD as soon as you moved
past one vCPU. Maybe the issue with gnulib's test-poll is related.

Note that libvirt is on d6397dde2e12 at the moment, but updating
to 0d10473be6fb (which is the current master) didn't help.


[1] https://www.redhat.com/archives/libvir-list/2018-May/msg00009.html
-- 
Andrea Bolognani / Red Hat / Virtualization