Re: Wait free LW_SHARED acquisition

On 2013-10-01 00:28:55 +0200, Bernd Helmle wrote:
> 
> 
> --On 30. September 2013 19:00:06 +0200 Andres Freund
> <andres@2ndquadrant.com> wrote:
> 
> >>HEAD (default):
> >>
> >>tps = 181738.607247 (including connections establishing)
> >>tps = 182665.993063 (excluding connections establishing)
> >>
> >>HEAD (padding + 16 partitions + your lwlocks patch applied):
> >>
> >>tps = 269328.259833 (including connections establishing)
> >>tps = 270685.666091 (excluding connections establishing)
> >>
> >>So, still an improvement but far away from what you got. Do you have some
> >>other tweaks in your setup?
> >
> >The only relevant setting changed was -c shared_buffers=1GB, no other
> >patches applied. At which scale did you pgbench -i?
> 
> I've used a scale factor of 10 (i recall you've mentioned using the same
> upthread...).
> 
> Okay, i've used 2GB shared buffers, repeating with your setting i get a far
> more noticable speedup:
> 
> tps = 346292.008580 (including connections establishing)
> tps = 347997.073595 (excluding connections establishing)

Could you send hierarchical profiles of both 1 and 2GB? It's curious
that the difference is that big... Even though they will be a bit big,
it'd be helpful if you pasted the output of "perf report --stdio", to
include the callers...

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services