Illustrative embodiments provide a computer implemented method, an apparatus in the form of a data processing system and a computer program product for cache line reservations. In one embodiment, the computer implemented method comprises, dividing a memory into an unreserved section and a set of reserved sections. The method performs selected allocations of the memory only from the set of reserved sections, and performing un-selected allocations of the memory from the unreserved section. The method further mapping a specified selected allocation of the memory to a same corresponding line of cache memory each time the mapping for the specified selected allocation of the memory occurs, thereby maintaining locality.