On Tue, Feb 9, 2010 at 11:37 PM, Greg Smith <g...@2ndquadrant.com> wrote: > 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.
I agree. I think the only way to really test it is by testing it against the system it's got to run under. I'd love to see someone do a comparison of early to mid 2.6 kernels (2.6.18 like RHEL5) to very up to date 2.6 kernels. On fast hardware. What it does on a laptop isn't that interesting and I don't have a big machine idle to test it on. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
