Re: Linux I/O tuning: CFQ vs. deadline

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