pgsql: Allow up to 3 "-P 1" reports per thread in pgbench run of 2 seco

Allow up to 3 "-P 1" reports per thread in pgbench run of 2 seconds.

There seems to be some considerable imprecision in the timing of -P
progress reports. Nominally each thread ought to produce 2 reports
in this test, but about 10% of the time we only get one, and 1% of
the time we get three, as per buildfarm results so far. Pending
further investigation, treat the last case as a "pass". (I, tgl,
am suspicious that this still might not be lax enough, now that it's
obvious that the behavior is load-dependent; but there's not yet
buildfarm evidence to confirm that suspicion.)

Fabien Coelho

Discussion: https://postgr.es/m/26654.1505232433@sss.pgh.pa.us

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/0f574a7afb5c998d19dc3d981e45cb10267286ed

Modified Files
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src/bin/pgbench/t/001_pgbench_with_server.pl | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)