Re: Move PinBuffer and UnpinBuffer to atomics

Hi, Dilip!

On Fri, Mar 25, 2016 at 8:32 PM, Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:

> On Fri, Mar 25, 2016 at 8:09 PM, Alexander Korotkov <
> a(dot)korotkov(at)postgrespro(dot)ru> wrote:
>
>> Could anybody run benchmarks? Feature freeze is soon, but it would be
>> *very nice* to fit it into 9.6 release cycle, because it greatly improves
>> scalability on large machines. Without this patch PostgreSQL 9.6 will be
>> significantly behind competitors like MySQL 5.7.
>
>
> I have run the performance and here are the results.. With latest patch I
> did not see any regression at lower client count (median of 3 reading).
>
> scale factor 1000 shared buffer 8GB readonly
> *Client Base patch*
> 1 12957 13068
> 2 24931 25816
> 4 46311 48767
> 32 300921 310062
> 64 387623 493843
> 128 249635 583513
> scale factor 300 shared buffer 8GB readonly
> *Client Base patch*
> 1 14537 14586 --> one thread number looks little less, generally I get
> ~18000 (will recheck).
> 2 34703 33929 --> may be run to run variance (once I get time, will
> recheck)
> 4 67744 69069
> 32 312575 336012
> 64 213312 539056
> 128 190139 380122
>
> *Summary:*
>
> Actually with 64 client we have seen ~470,000 TPS with head also, by
> revering commit 6150a1b0.
> refer this thread: (
> http://www.postgresql.org/message-id/CAA4eK1+ZeB8PMwwktf+3bRS0Pt4Ux6Rs6Aom0uip8c6shJWmyg@mail.gmail.com
> )
>
> I haven't tested this patch by reverting commit 6150a1b0, so not sure can
> this patch give even better performance ?
>
> It also points to the case, what Andres has mentioned in this thread.
>
>
> http://www.postgresql.org/message-id/20160226191158.3vidtk3ktcmhimdu@alap3.anarazel.de
>

Thank you very much for testing!
I also got access to 4 x 18 Intel server with 144 threads. I'm going to
post results of tests on this server in next Monday.

------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company