Re: high io BUT huge amount of free memory

On Wed, Apr 24, 2013 at 08:39:09AM -0500, 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?
>
> Well... it is. But even on systems where it's not the default or is
> explicitly disabled, there's just something hideously wrong with
> NUMA in general. Take a look at our numa distribution on a heavily
> loaded system:
>
> available: 2 nodes (0-1)
> node 0 cpus: 0 2 4 6 8 10 12 14 16 18 20 22
> node 0 size: 36853 MB
> node 0 free: 14315 MB
> node 1 cpus: 1 3 5 7 9 11 13 15 17 19 21 23
> node 1 size: 36863 MB
> node 1 free: 300 MB
> node distances:
> node 0 1
> 0: 10 20
> 1: 20 10
>
> What the hell? Seriously? Using numactl and starting in interleave
> didn't fix this, either. It just... arbitrarily ignores a huge chunk
> of memory for no discernible reason.

Sorry to be dense here, but what is the problem with that output? That
there is a lot of memory marked as "free"? Why would it mark any memory
free?

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +