Re: [PATCH 0/2] Disable zone_reclaim_mode by default

From: Josh Berkus
Date: Tue Apr 08 2014 - 15:57:03 EST


On 04/08/2014 03:53 PM, Robert Haas wrote:
> In an ideal world, the kernel would put the hottest pages on the local
> node and the less-hot pages on remote nodes, moving pages around as
> the workload shifts. In practice, that's probably pretty hard.
> Fortunately, it's not nearly as important as making sure we don't
> unnecessarily hit the disk, which is infinitely slower than any memory
> bank.

Even if the kernel could do this, we would *still* have to disable it
for PostgreSQL, since our double-buffering makes our pages look "cold"
to the kernel ... as discussed.

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com
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