Reserved Memory Insight

[Willem Grooters]

It will depend on a number of parameters:
* process-local or global?
* Is memory allocated from reserved adress space or from the general heap?
* Are pages sawapped out, need to be read in to check if data needs to be written first?

Check the virtual-memory- and disk activity.

[Marc Van den Broeck]

Willem,

as far as I know reserved memory is mapped in physical memory and never swapped out. Or am I wrong?

Rgds
Marc

[Willem Grooters]

Reserving memory is always, AFAIK, a matter of virtual address space, and, unless explictly stated otherwise, referring to paged pool. It does not have to mean that memory is already allocated on reservation. That can be done at need.
But this is application dependent, and I don't know how Oracle has implemented this (I know how I did it ;-))

[Hein van den Heuvel]

Willem,

When OpenVMS / Oracle folks talk about 'Reserved Memory' they are talkign PHYSICAL MEMORY. Nothing to do with pool.

Just hit Google with +openvms +"reserved memory"

You will notably find the following article by Karen and Nitin:

http://research.compaq.com/wrl/DECarchives/DTJ/DTJS03/DTJS03PF.PDF


Hein.

[Jack Trachtman]

Thanks to all who've replied.

Some quick notes:

I don't presently have a test system
so I can't try some of the suggestions.

I will read the DEC Journal paper referenced
and the VMS VLM manual to get more background.

Actually, I was hoping that someone from
VMS internals would jump in...