MPAS Attributes

[gm200]

In relation with the previous message "Allocation Shared Memory Limit 2.75GB wolkaround" with 32bit executable compiled, I have read on an HP technical white paper ("Adaptative Address Space") the possibility to use all the "4GB, i.e. all the 4 quadrants," [...] "for the process to consume in any manner it chooses" by using the MPAS process attribute (chatr -as mpas). Do someone know if this option work only for ITANIUM or also on PA-RISC (64bit maschine S.O. 11.23)? Can someone provide some information about? Can I use this option in conjuntion with the memory window functionality?

Thanks
GM200

[Arunvijai_4]

Hi,

You can check this thread at DSPP,

http://h21007.www2.hp.com/dspp/ml/showArchiveMessage/1,,4!04!01!0054,00.html

-Arun

[Don Morris_1 · Accepted solution]

MPAS is Itanium only. PA-RISC doesn't support the aliasing features needed to make MPAS work.

Memory Windows can be used at the same time as MPAS from a system-viewpoint, but there's no meaning to having Memory Windows in an MPAS process -- it has the entire address space to work with (for 32-bit, 64-bit actually do include a section of the global shared address space as well... but 64-bit processes don't need memory windows (yet, anyway... when are you folks going to start consuming exabytes? :) ) so that's a moot point). Anything it needs to share gets mapped to a private alias within the MPAS process - doesn't matter how it gets shared to non-MPAS, really.

For 11.23 PA-RISC, if you need more than 2.75Gb of shared address space -- you must go 64-bit. Besides -- if you're hitting 3Gb now - you know you'll be hitting 4Gb soon enough, and nothing's going to save you in 32-bit land at that point.

[gm200]

I cannot solve the problem