Software DSM

Address space partitioned address equivalence
distributed ownership
contact owner of page to get current copy

application, global virtual memory abstraction, dsm software implementation, local physical memeories

LRC with multi-writer coherence protocol
PI lock(L);
x, y, z pages modified in cs => Xd, Yd, Zd } diffs
unlock(L); fetch at point of access
P3 lock(L); x <- => X’d unlock(L);

Implementation
write(x), twin, original writable
release run-length encoded