Jeff wrote:
> I'd done some testing a while ago on the schedulers and at the time
> deadline or noop smashed cfq. Now, it is 100% possible since then
> that they've made vast improvements to cfq and or the VM to get better
> or similar performance. I recall a vintage of 2.6 where they severely
> messed up the VM. Glad I didn't upgrade to that one :)
>
> Here's the old post:
> http://archives.postgresql.org/pgsql-performance/2008-04/msg00155.php
pgiosim doesn't really mix writes into there though, does it? The mixed
read/write situations are the ones where the scheduler stuff gets messy.
--
Greg Smith 2ndQuadrant Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com www.2ndQuadrant.com