Re: Wait free LW_SHARED acquisition - v0.9

On Sat, Oct 11, 2014 at 6:40 PM, Andres Freund <andres(at)2ndquadrant(dot)com>
wrote:
> On 2014-10-11 07:26:57 +0530, Amit Kapila wrote:
> > On Sat, Oct 11, 2014 at 7:00 AM, Andres Freund <andres(at)2ndquadrant(dot)com>
> > > And since
> > > your general performance numbers are a fair bit lower than what I see
> > > with, hopefully, the same code on the same machine...
> >
> > You have reported numbers at 1000 scale factor and mine were
> > at 3000 scale factor, so I think the difference is expected.
>
> The numbers for 3000 show pretty much the same:
>
> SCALE 128 160 175
> HEAD 352113 339005 336491
> LW_SHARED 365874 347931 342528
>
> Hm. I wonder if you're using pgbench without -M prepared?

No, I use below statement:
./pgbench -c 128 -j 128 -T 300 -S -M prepared postgres

> That'd about
> explain the difference.

Here I think first thing to clarify is why the numbers on HEAD are
different? Another thing is that I generally see difference in
numbers at 1000 and 3000 scale factor (although I have not run
lately), but in your case the numbers are almost same.

I will try once more by cleaning every thing(installation, data_dir, etc..)
but not today...

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com