1. A system for memory management, the system comprising a tag cache in communication with one or more cache devices in a storage hierarchy, wherein: the tag cache includes tags of recently accessed memory blocks, each tag corresponding to one of the memory blocks and each tag including tag contents; and the tag contents control which memory lines of the corresponding memory block are prefetched into at least one of the cache devices; wherein the tag contents further include a bit to control prefetching of memory lines from a next virtual memory block, said bit referred to as a next virtual memory block bit; wherein the next virtual memory block bit in a preceding memory block in a virtual address space is set to a prefetch status when the preceding memory block tag is in the tag cache; and wherein the next virtual memory block bit is turned to a nonprefetch status with a specified probability on certain events.