Re: high io BUT huge amount of free memory

On 04/24/2013 09:39 PM, Shaun Thomas wrote:
> On 04/24/2013 08:24 AM, Robert Haas wrote:
>
>> Are you referring to the fact that vm.zone_reclaim_mode = 1 is an
>> idiotic default?
> Servers are getting shafted in a lot of cases, and it's actually
> starting to make me angry.
>

A significant part of that problem is that desktop users and people
developing for desktops *test* kernels before or shortly after their
release.

Most server operators won't let a new kernel anywhere near their
machines, so reports of problems on big real-world servers lag severely
behind Linux kernel development.

By the time last years' issues are fixed, there's a whole new crop of
issues that make the new kernel problematic in other ways.

There *are* teams testing new kernels on big hardware, but this takes
money and resources not everyone has. They're also limited in what tests
the have available to them. One of the big things that you can do to
help is *produce automated test cases* that demonstrate performance
problems so they can be incorporated into future kernel testing and
benchmarking processes. You can also help test newer kernels to see if
your issues are fixed.

I know full well how frustrating it can be when you feel your use cases
and problems are ignored or dismissed (I've worked on Java EE) ... but
the only way I've ever found to get genuine progress is to put that
aside and help.

--
Craig Ringer http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services