X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 0B145DBA7B for ; Wed, 23 Nov 2005 14:15:05 -0400 (AST) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 50188-07-2 for ; Wed, 23 Nov 2005 18:15:00 +0000 (GMT) X-Greylist: from auto-whitelisted by SQLgrey- Received: from smtp.nildram.co.uk (smtp.nildram.co.uk [195.112.4.54]) by svr1.postgresql.org (Postfix) with ESMTP id 1F8E6DBA81 for ; Wed, 23 Nov 2005 14:14:56 -0400 (AST) Received: from [192.168.0.4] (unknown [84.12.200.148]) by smtp.nildram.co.uk (Postfix) with ESMTP id 8E25825E762; Wed, 23 Nov 2005 18:14:50 +0000 (GMT) Subject: Re: High context switches occurring From: Simon Riggs To: Anjan Dave Cc: Scott Marlowe , Tom Lane , Vivek Khera , Postgresql Performance In-Reply-To: <4BAFBB6B9CC46F41B2AD7D9F4BBAF785098E78@vt-pe2550-001.vantage.vantage.com> References: <4BAFBB6B9CC46F41B2AD7D9F4BBAF785098E78@vt-pe2550-001.vantage.vantage.com> Content-Type: text/plain Date: Wed, 23 Nov 2005 18:13:58 +0000 Message-Id: <1132769638.4347.7.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.2.2 (2.2.2-5) Content-Transfer-Encoding: 7bit X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0 required=5 tests=[AWL=0.000] X-Spam-Score: 0 X-Spam-Level: X-Archive-Number: 200511/472 X-Sequence-Number: 15729 On Tue, 2005-11-22 at 18:17 -0500, Anjan Dave wrote: > It's mostly a 'read' application, I increased the vm.max-readahead to > 2048 from the default 256, after which I've not seen the CS storm, > though it could be incidental. Can you verify this, please? Turn it back down again, try the test, then reset and try the test. If that is a repeatable way of recreating one manifestation of the problem then we will be further ahead than we are now. Thanks, Best Regards, Simon Riggs