Memory Management for Self-stabilizing Operating Systems

This work presents several approaches for designing the memory management component of self-stabilizing operating systems. We state the requirements a memory manager should satisfy. One requirement is eventual memory hierarchy consistency among different copies of data residing in different (level of) memory devices e.g., RAM and Disk. Another requirement is stabilization preservation a condition in which the memory manager ensures that every process that is proven to stabilize independently, stabilizes under the (self-stabilizing scheduler and) memory manager operation too. Three memory managers that satisfy the above requirements are presented. The first allocates the entire physical memory to a single process at every given point in time. The second one uses fixed partition of memory between processes, while the last one uses memory leases for dynamic memory allocations. The use of leases in the scope of memory allocation in the operating system level is a new and important aspect of our self-stabilizing memory management. ∗Partially supported by Rafael, IBM, NSF, Intel, Deutsche Telekom, Rita Altura Trust Chair in Computer Sciences and Lynn and William Frankel Center for Computer Sciences. †Also at: Rafael 3M, POB 2205, Haifa, Israel.