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Re: LDM 6.2.1 possible memory issue?

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  • Subject: Re: LDM 6.2.1 possible memory issue?
  • Date: Tue, 08 Mar 2005 16:48:53 -0700
Steven,

>Date: Tue, 08 Mar 2005 16:13:09 -0600
>From: "Steven Danz" <address@hidden>
>Organization: Aviation Weather Center
>To: Steve Emmerson <address@hidden>
>Subject: Re: LDM 6.2.1 possible memory issue?

The above message contained the following:

> I've attached the ps status you asked for.

Thanks.  I plotted the data and didn't see any evidence of a memory-leak.

> Isn't it true that a process that 'touches' all its allocated memory
> will show a larger RSS than one that allocates the memory but only
> accesses small regions of it at a time?

Whether or not that's true depends on the memory-management system of
the operating-system.  I'm afraid I don't know enough details to say one
way or another.

> That is of course within limits of available physical RAM.  I seem
> to remember that the Linux kernel is particularly agressive in
> paging/swapping out unused portions of programs to allow for more
> cache/buffer space.  (Which is why I'm guessing my 600Meg X server
> only has a 64Meg RSS).

I think that Linux uses a least-recently-used algorithm for swapping-out
pages.

> If it was queue size related, shouldn't the VSS be more along the
> lines of 800Meg to start and not ~796Meg?  The queue was created with
> "800M" in the config file, and du -sH shows it as 814Meg.

What does an "ls -l" show for the size?

> Thanks for your time!

You're welcome.

> Steven
> 
> -- 
> Steven Danz
> Senior Software Development Engineer
> Aviation Weather Center (NOAA/NWS/NCEP)
> 7220 NW 101st Terrace, Room 101
> Kansas City, MO 64153-2371
> 
> Email: address@hidden
> Phone: 816.584.7251
> Fax:   816.880.0650
> URL:   http://aviationweather.gov/
> 
> The opinions expressed in this message do not necessarily reflect those 
> of the National Weather Service, or the Aviation Weather Center.

Regards,
Steve Emmerson