Wierd context-switching issue on Xeon - Mailing list pgsql-performance

From Josh Berkus
Subject Wierd context-switching issue on Xeon
Date
Msg-id 200311251419.36771.josh@agliodbs.com
Whole thread Raw
Responses Re: Wierd context-switching issue on Xeon
List pgsql-performance
Folks,

We're seeing some odd issues with hyperthreading-capable Xeons, whether or not
hyperthreading is enabled.   Basically, when a small number of really-heavy
duty queries hit the system and push all of the CPUs to more than 70% used
(about 1/2 user & 1/2 kernel), the system goes to 100,000+ context switcthes
per second and performance degrades.

I know that there's other Xeon users on this list ... has anyone else seen
anything like that?   The machines are Dells running Red Hat 7.3.

--
-Josh Berkus
 Aglio Database Solutions
 San Francisco


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