EXEC_MAGIC & available memory for a single process

[Conal O'Kelly]

Hi
I have posted similar questions around this topic before, so I apologise if I am repeating myself but I still need a bit of help understanding this.
I am trying to determine why a particular process is not grabbing more than 950MB (figures from ps - vsz & glance). This is a 32bit oracle application & I know from previous responses that normally these are constrained to ~960MB. However I have since determined it has been compiled with the EXEC_MAGIC flag and hence should potentially have up to 1.9GB of memory available (from quadrants 1 &2??). Previous post's have indicated there is no gaurantee this extra memory will be available. I'm having difficulty understanding why and if there is anything that can be done to give the process a better chance of grabbing the additional memory that should be available (apart from re-compiling as 64bit). The system is an L-3000 with 4GB of phys (there is consistently about 1.5GB of free memory) and was purchased exclusively for this application.

Any help greatly appreciated.

Cheers
Con

[Patrick Wallek]

Here's your previous thread:
http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x57ca94f22a31d6118fff0090279cd0f9,00.html

I think Clays response is about your best explanation. You might have 1.5GB of memory available, but there might be a 940 MB chunk here, a 300 MB chunk over there and another 300 MB chunk somewhere else.

Now since all of those areas are not contiguous, ie. NOT one big 1.5GB free area, you won't get them all.

As Clay said, it's a crap shoot as to how much memory you get.

Can you not convert this application to be a 64-bit application and use 64-bit Oracle?

[Conal O'Kelly]

Thanks Patrick, I'd missed the point about contiguous space being available.

Cheers
Con