Memory Management

Memory management under OS/2 2.0 provides access to larger amounts of physical and virtual memory in a more efficient manner than in previous versions of the OS/2 operating system. It also removes many of the constraints imposed by previous versions. At the same time, the enhanced memory management maintains compatibility with 16-bit applications and resources. OS/2 2.0 introduces a flat memory model with a linear address space of 4GB (GB equals 1024MB). Designed to be used with the Intel (or compatible) 80386SX (or higher) microprocessor, OS/2 2.0 takes full advantage of such 32-bit features as 32-bit register set, 32-bit instructions and addressing, large memory objects (greater than 64KB), and paging.

Paging enables an application to request large memory objects, and access and manipulate those objects as logical entities. Paging also enables a more efficient implementation of virtual memory, because individual pages, rather than entire memory objects, can be swapped in and out of real memory. Paging has good performance, especially when memory objects become very large.