On Feb 8, 2010, at 11:35 PM, david@lang.hm wrote:
>
>> And, yes, the whole I/O scheduling approach in Linux was just
>> completely redesigned for a very recent kernel update. So even
>> what we think we know is already obsolete in some respects.
>>
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
--
Jeff Trout <jeff@jefftrout.com>
http://www.stuarthamm.net/
http://www.dellsmartexitin.com/