I just found one thing making check-world slower than it ought to be:
src/test/recovery/t/008_fsm_truncation.pl does
$node_primary->append_conf(
'postgresql.conf', qq{
fsync = on
wal_log_hints = on
max_prepared_transactions = 5
autovacuum = off
});
There is no reason for this script to be overriding Cluster.pm's
fsync = off setting. This actually causes parallel check-world to
fail altogether on florican's host, because the initial fsync of
the recovered primary takes more than 3 minutes when there's
conflicting I/O traffic, causing pg_ctl to time out.
This appears to go back to 917dc7d23 of 2016, so I think it just
predates our recognition that we should disable fsync in routine
tests.
regards, tom lane
