Re: Move PinBuffer and UnpinBuffer to atomics

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

Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com