Message-ID: <50BFC9D8.4010507@optionshouse.com>
Date: Wed, 5 Dec 2012 16:25:28 -0600
From: Shaun Thomas <sthomas@optionshouse.com>
Reply-To: <sthomas@optionshouse.com>
Organization: Peak6
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To: Daniel Farina <daniel@heroku.com>
CC: "pgsql-performance@postgresql.org" <pgsql-performance@postgresql.org>
Subject: Re: Ubuntu 12.04 / 3.2 Kernel Bad for PostgreSQL Performance
References: <50BF9247.2010800@optionshouse.com>
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On 12/05/2012 04:19 PM, Daniel Farina wrote:

> Is 3.2 a significant regression from previous releases, or is 3.4 just
> faster?  Your wording only indicates that "older kernel is slow," but
> your tone would suggest that you feel this is a regression, cf.

It's definitely a regression. I'm trying to pin it down, but the 
3.2.0-24 kernel didn't do the CPU drain down to single-digits on that 
client load test. I'm working on 3.2.0-30 and going down to figure out 
which patch might have done it.

Older kernels performed better. And by older, I mean 2.6. Still not 3.4 
levels, but that's expected. I haven't checked 3.0, but other threads 
I've read suggest it had less problems. Sorry if I wasn't clear.

-- 
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd. | Suite 500 | Chicago IL, 60604
312-444-8534
sthomas@optionshouse.com

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