Re: Wait free LW_SHARED acquisition - v0.9

On Sat, Oct 11, 2014 at 7:02 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> On Sat, Oct 11, 2014 at 6:40 PM, Andres Freund <andres@2ndquadrant.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@2ndquadrant.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?

I have taken the latest code and recreated the database and tried