Re: Ubuntu 12.04 / 3.2 Kernel Bad for PostgreSQL Performance

On Wed, Dec  5, 2012 at 04:25:28PM -0600, Shaun Thomas wrote:
> 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.

Ah, that is interesting about 2.6.  I had wondered how Debian stable
would have performed, 2.6.32-5.  This relates to a recent discussion
about the appropriateness of Ubuntu for database servers:

    http://archives.postgresql.org/pgsql-performance/2012-11/msg00358.php

Thanks.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +