Re: Trivial HugeTLB Benchmark

Ryan Cumming <ryan(dot)cumming(at)neverbluemedia(dot)com> writes:
> I ran each pgbench after a fresh reboot. I used 85 huge pages reserved at boot for the huge page test, and none for the normal shared memory test.

> Normal shared memory:
> -bash-3.00$ pgbench -c 5 -t 10000
> starting vacuum...end.
> transaction type: TPC-B (sort of)
> scaling factor: 1
> number of clients: 5
> number of transactions per client: 10000
> number of transactions actually processed: 50000/50000
> tps = 1669.009344 (including connections establishing)
> tps = 1669.941756 (excluding connections establishing)

If you did this only once, the results are not really trustworthy;
you need to average several similar runs before you can have much
confidence. pgbench's inter-run variation is usually upwards of 10%,
so trying to draw conclusions about half-percentage-point differences
without averaging is a waste of time.

Also, if scaling factor < number of clients then what you're mostly
measuring is update-contention behavior. Try it with -s 10 and -c 5;
and don't forget to reinitialize the database for each run of tests
to be sure it's fair.

regards, tom lane