SDI Seminar

Speaker: Wayne Sawdon and Matt Zeukauskas

Software Write Detection in DSM Systems

Date: March 3, 1994

Abstract: A unique feature of the Midway distributed shared memory system is that it does not use the virtual memory page protection to detect writes to shared data. Instead, the compiler and runtime system cooperate to maintain reference information. Midway's scheme has a constant overhead for writes, no matter how often the processors synchronize, while virtual memory schemes have a fixed cost per synchronization. Depending on the reference pattern, Midway's scheme can have a lower average write latency than virtual memory schemes. This informal talk will describe work in progress to compare and contrast the current state of the art with Midway's software dirty bits.