Adaptive Address Space Whitepaper

bit process is shown below. This type of layout is called MGAS (for Mostly Global

Address Space). The layout is:

(The diagram shows a 64-bit MGAS process on IPF. Note, the figure is not drawn to scale.

The maximum stack sizes are decided by system tunables and process resource limits at

the time of process start-up).

For a 64-bit process, text can occupy up to 1 octant. This entire octant is not

available to the application for any other use.

64-bit MGAS applications share data among themselves by using the same

mechanism as 32-bit applications (i.e. the data is attached to the shared virtual

address space, and all sharing processes access it using the same virtual

address. This eliminates the need for aliasing of virtual addresses. But shared

virtual address consumed by one process will impact other processes). Shared