Re: Strange behavior: pgbench and new Linux kernels

On Thu, Apr 17, 2008 at 12:58 AM, Greg Smith <gsmith@gregsmith.com> wrote:
>  So in the case of this simple benchmark, I see an enormous performance
> regression from the newest Linux kernel compared to a much older one.

This has been discussed recently on linux-kernel.  It's definitely a
regression.  Instead of getting a nice, flat overload behavior when
the # of busy threads exceeds the number of CPUs, you get the
declining performance you noted.

Poor PostgreSQL scaling on Linux 2.6.25-rc5 (vs 2.6.22)
http://marc.info/?l=linux-kernel&m=120521826111587&w=2

-jwb