Horton

Re: Perfomance degradation 9.3 (vs 9.2) for FreeBSD

Tatsuo Ishii <ishii@postgresql.org>

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From: Tatsuo Ishii <ishii@postgresql.org>
To: girgen@FreeBSD.org
Cc: pgsql-hackers@postgresql.org, robertmhaas@gmail.com, ftigeot@wolfpond.org
Date: 2014-04-22T00:34:58Z
Lists: pgsql-hackers

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  1. Add shared_memory_type GUC.

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> I see performance degradation with PostgreSQL 9.3 vs 9.2 on FreeBSD, and I'm wondering who to poke to mitigate the problem. In reference to this thread [1], who where the FreeBSD people that Francois mentioned? If mmap needs to perform well in the kernel, I'd like to know of someone with FreeBSD kernel knowledge who is interested in working with mmap perfocmance. If mmap is indeed the cuplrit, I've just tested 9.2.8 vs 9.3.4, I nevere isolated the mmap patch, although I believe Francois did just that with similar results.

I observe performance degradation with PostgreSQL 9.3 vs 9.2 on Linux
as well.  The hardware is HP DL980G7, 80 cores, 2TB mem, RHEL 6,
pgbench is used (read only query), scale factor is 1,000 (DB size
15GB).

Included is the graph (from PostgreSQL Enterprise Consortium's 2014
report page 13: https://www.pgecons.org/downloads/43). I see up to 14%
degration (at 128 concurrent users) comparing with 9.2.

Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp