Re: linux, memory (mis)accounting/reporting, and the planner/optimizer - Mailing list pgsql-performance

From M. Edward (Ed) Borasky
Subject Re: linux, memory (mis)accounting/reporting, and the planner/optimizer
Date
Msg-id 497810F1.5050309@cesmail.net
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In response to Re: linux, memory (mis)accounting/reporting, and the planner/optimizer  (Greg Smith <gsmith@gregsmith.com>)
Responses Re: linux, memory (mis)accounting/reporting, and the planner/optimizer  (Greg Smith <gsmith@gregsmith.com>)
List pgsql-performance
Greg Smith wrote:
> On Wed, 21 Jan 2009, Dave Youatt wrote:
>
>> Does it just accept the configuration parameters provided (e.g. --
>> shared_buffers, effective_cache_size, etc.)?
>
> That's it.  The only time PostgreSQL gets a report from the OS related
> to memory is if it makes an allocation attempt that fails.  Couldn't
> care less what Linux thinks the rest of the time--unless the OOM killer
> goes on a rampage, counts shared memory badly, and decides to kill a
> database process that is.
>
> --
> * Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD
>

The shared memory accounting in Linux got better in the 2.6.25 kernel,
although I'm not sure the user space tools are fully deployed even today
to track it. And of course, lots of servers still use kernels older than
2.6.25.

Re the OOM killer -- maybe a patch to the kernel could make things
"better"??

--
M. Edward (Ed) Borasky

I've never met a happy clam. In fact, most of them were pretty steamed.

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