Perfomance degradation 9.3 (vs 9.2) for FreeBSD

Palle Girgensohn <girgen@freebsd.org>

From: Palle Girgensohn <girgen@FreeBSD.org>

To: PostgreSQL Hackers <pgsql-hackers@postgresql.org>

Cc: Robert Haas <robertmhaas@gmail.com>, Francois Tigeot <ftigeot@wolfpond.org>

Date: 2014-04-20T09:24:38Z

Lists: pgsql-hackers

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Add shared_memory_type GUC.
- f1bebef60ec8 12.0 landed

Attachments

FreeBSD PostgreSQL mmap performance.pdf (application/pdf)
(unnamed) (text/plain)

Hi!

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.

Enclosed is a report from a simple pgbench check.

Palle

[1] http://www.postgresql.org/message-id/20130126120024.GA21101@sekishi.zefyris.com