Re: Possible performance regression in version 10.1 with pgbench read-write tests.

On Thu, Feb 22, 2018 at 7:55 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Wed, Feb 21, 2018 at 10:03 PM, Mithun Cy <mithun.cy@enterprisedb.com> wrote:
>> seeing futex in the call stack andres suggested that following commit could
>> be the reason for regression
>>
>> commit ecb0d20a9d2e09b7112d3b192047f711f9ff7e59
>> Author: Tom Lane <tgl@sss.pgh.pa.us>
>> Date:   2016-10-09 18:03:45 -0400
>>
>>     Use unnamed POSIX semaphores, if available, on Linux and FreeBSD.
>>
>> Commenting out same in src/template/linux I did run the benchmark tests
>> again
>> performance improved from 26871.567326 to 34286.620251 (both median of 3
>> TPS).
>
> Hmm.  So that commit might not have been the greatest idea.
>

It appears so.  I think we should do something about it as the
regression is quite noticeable.

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