Re: [HACKERS] LWLock optimization for multicore Power machines

Am Montag, den 06.02.2017, 16:45 +0300 schrieb Alexander Korotkov:
> I tried lwlock-power-2.patch on multicore Power machine we have in
> PostgresPro.
> I realized that using labels in assembly isn't safe.  Thus, I removed
> labels and use relative jumps instead (lwlock-power-2.patch).
> Unfortunately, I didn't manage to make any reasonable benchmarks. 
> This
> machine runs AIX, and there are a lot of problems which prevents
> PostgreSQL
> to show high TPS.  Installing Linux there is not an option too,
> because
> that machine is used for tries to make Postgres work properly on AIX.
> So, benchmarking help is very relevant.  I would very appreciate
> that.

Okay, so here are some results. The bench runs against
current PostgreSQL master, 24 GByte shared_buffers configured (128
GByte physical RAM), max_wal_size=8GB and effective_cache_size=100GB.

1. Have you warm up database?  I.e. could you do "SELECT sum(x.x) FROM (SELECT pg_prewarm(oid) AS x FROM pg_class WHERE relkind IN ('i', 'r') ORDER BY oid) x;" before each run?
   
2. Also could you run each test longer: 3-5 mins, and run them with variety of clients count?