Horton

Re: Wierd context-switching issue on Xeon

Robert Creager <robert_creager@logicalchaos.org>

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From: Robert Creager <Robert_Creager@LogicalChaos.org>
To: Josh Berkus <josh@agliodbs.com>
Cc: pg@fastcrypt.com, Dirk_Lutzebäck <lutzeb@aeccom.com>, ohp@pyrenet.fr, Tom Lane <tgl@sss.pgh.pa.us>, Joe Conway <mail@joeconway.com>, "scott.marlowe" <scott.marlowe@ihs.com>, Bruce Momjian <pgman@candle.pha.pa.us>, pgsql-performance@postgresql.org, Neil Conway <neilc@samurai.com>
Date: 2004-04-29T00:57:53Z
Lists: pgsql-performance 
When grilled further on (Wed, 21 Apr 2004 10:29:43 -0700),
Josh Berkus <josh@agliodbs.com> confessed:

> Dave,
> 
> > After some testing if you use the current head code for s_lock.c which
> > has some mods in it to alleviate this situation, and change
> > SPINS_PER_DELAY to 10 you can drastically reduce the cs with tom's test.
> > I am seeing a slight degradation in throughput using pgbench -c 10 -t
> > 1000 but it might be liveable, considering the alternative is unbearable
> > in some situations.
> >
> > Can anyone else replicate my results?
> 
> Can you produce a patch against 7.4.1?   I'd like to test your fix against a 
> real-world database.

I would like to see the same, as I have a system that exhibits the same behavior
on a production db that's running 7.4.1.

Cheers,
Rob


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