Support for exhaustion recovery in a data processing system with memory mirroring

A memory exhaustion condition is handled in a data processing system having first and second regions of physical memory. The memory exhaustion condition is detected while the second region is mirroring at least part of the first region. In response to the memory exhaustion condition, memory mirroring is at least partially deactivated and at least part of the second region is utilized to augment the first region, such that the memory exhaustion condition is eliminated. In an illustrative embodiment, the data processing system compresses real memory into the first region of physical memory, and the memory exhaustion condition arises when the first region lacks sufficient available capacity to accommodate current requirements for real memory. The memory exhaustion condition is eliminated by compressing at least part of the real memory into the second region.