Horton

Re: Wierd context-switching issue on Xeon

Matthew T. O'Connor <matthew@zeut.net>

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From: "Matthew T. O'Connor" <matthew@zeut.net>
To: Robert Creager <Robert_Creager@LogicalChaos.org>
Cc: Bruce Momjian <pgman@candle.pha.pa.us>, pg@fastcrypt.com, Josh Berkus <josh@agliodbs.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>, pgsql-performance@postgresql.org, Neil Conway <neilc@samurai.com>
Date: 2004-05-20T05:10:14Z
Lists: pgsql-performance 
On Wed, 2004-05-19 at 21:59, Robert Creager wrote:
> When grilled further on (Wed, 19 May 2004 21:20:20 -0400 (EDT)),
> Bruce Momjian <pgman@candle.pha.pa.us> confessed:
> 
> > 
> > Did we ever come to a conclusion about excessive SMP context switching
> > under load?
> > 
> 
> I just figured out what was causing the problem on my system Monday.  I'm using
> the pg_autovacuum daemon, and it was not vacuuming my db.  I've no idea why and
> didn't get a chance to investigate.

Strange.  There is a known bug in the 7.4.2 version of pg_autovacuum
related to data type mismatches which is fixed in CVS.  But that bug
doesn't cause pg_autovacuum to stop vacuuming but rather to vacuum to
often.  So perhaps this is a different issue?  Please let me know what
you find.

Thanks,

Matthew O'Connor