Re: Possible performance regression in version 10.1 with pgbench read-write tests.
Robert Haas <robertmhaas@gmail.com>
From: Robert Haas <robertmhaas@gmail.com>
To: Mithun Cy <mithun.cy@enterprisedb.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>,
Amit Kapila <amit.kapila16@gmail.com>
Date: 2018-02-22T14:25:28Z
Lists: pgsql-hackers
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. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
Commits
-
Pad semaphores to avoid false sharing.
- 46201d603f9c 10.5 landed
- f2db5f3bb0b5 11.0 landed
- 2d3067595299 12.0 landed