Re: oom_killer

From: Claudio Freire <klaussfreire(at)gmail(dot)com>
To: Cédric Villemain <cedric(dot)villemain(dot)debian(at)gmail(dot)com>
Cc: Tory M Blue <tmblue(at)gmail(dot)com>, Merlin Moncure <mmoncure(at)gmail(dot)com>, pgsql-performance(at)postgresql(dot)org
Subject: Re: oom_killer
Date: 2011-04-22 23:19:19
Message-ID: BANLkTimwYuoq+gKqcjJtgqjEv6kf5zwbZA@mail.gmail.com
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On Fri, Apr 22, 2011 at 6:45 PM, Cédric Villemain
<cedric(dot)villemain(dot)debian(at)gmail(dot)com> wrote:
> Are you sure it is a PAE kernel ? You look limited to 4GB.

If my memory/knowledge serves me right, PAE doesn't remove that limit.
PAE allows more processes, and they can use more memory together, but
one process alone has to live within an addressable range, and that is
still 4GB, mandated by the 32-bit addressable space when operating in
linear addressing mode.

But linux kernels usually reserve 1GB for kernel stuff (buffers and
that kind of stuff), so the addressable portion for processes is 3GB.

Take away 2.5GB of shared buffers, and you only leave 0.5G for general
data and code.

Really, lowering shared_buffers will probably be a solution. Moving to
64 bits would be a better one.

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