Re: 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.

I've just discovered that max_connections was accidently set to 601,
normally i'd have set something near 110 or so...

<master afcb0c97efc58459bcbbe795f42d8b7be414e076>

transaction type: <builtin: select only>
scaling factor: 1000
query mode: prepared
number of clients: 100
number of threads: 100
duration: 30 s
number of transactions actually processed: 16910687
latency average = 0.177 ms
tps = 563654.968585 (including connections establishing)
tps = 563991.459659 (excluding connections establishing)
transaction type: <builtin: select only>
scaling factor: 1000
query mode: prepared
number of clients: 100
number of threads: 100
duration: 30 s
number of transactions actually processed: 16523247
latency average = 0.182 ms
tps = 550744.748084 (including connections establishing)
tps = 552069.267389 (excluding connections establishing)
transaction type: <builtin: select only>
scaling factor: 1000
query mode: prepared
number of clients: 100
number of threads: 100
duration: 30 s
number of transactions actually processed: 16796056
latency average = 0.179 ms
tps = 559830.986738 (including connections establishing)
tps = 560333.682010 (excluding connections establishing)

<lw-lock-power-1.patch applied>

transaction type: <builtin: select only>
scaling factor: 1000
query mode: prepared
number of clients: 100
number of threads: 100
duration: 30 s
number of transactions actually processed: 14563500
latency average = 0.206 ms
tps = 485420.764515 (including connections establishing)
tps = 485720.606371 (excluding connections establishing)
transaction type: <builtin: select only>
scaling factor: 1000
query mode: prepared
number of clients: 100
number of threads: 100
duration: 30 s
number of transactions actually processed: 14618457
latency average = 0.205 ms
tps = 487246.817758 (including connections establishing)
tps = 488117.718816 (excluding connections establishing)
transaction type: <builtin: select only>
scaling factor: 1000
query mode: prepared
number of clients: 100
number of threads: 100
duration: 30 s
number of transactions actually processed: 14522462
latency average = 0.207 ms
tps = 484052.194063 (including connections establishing)
tps = 485434.771590 (excluding connections establishing)

<lw-lock-power-3.patch applied>

transaction type: <builtin: select only>
scaling factor: 1000
query mode: prepared
number of clients: 100
number of threads: 100
duration: 30 s
number of transactions actually processed: 17946058
latency average = 0.167 ms
tps = 598164.841490 (including connections establishing)
tps = 598582.503248 (excluding connections establishing)
transaction type: <builtin: select only>
scaling factor: 1000
query mode: prepared
number of clients: 100
number of threads: 100
duration: 30 s
number of transactions actually processed: 17719648
latency average = 0.169 ms
tps = 590621.671588 (including connections establishing)
tps = 591093.333153 (excluding connections establishing)
transaction type: <builtin: select only>
scaling factor: 1000
query mode: prepared
number of clients: 100
number of threads: 100
duration: 30 s
number of transactions actually processed: 17722941
latency average = 0.169 ms
tps = 590728.715465 (including connections establishing)
tps = 591619.817043 (excluding connections establishing)