An Efficient Lock Protocol for Home-Based Lazy Release Consistency

Home-based Lazy Release Consistency (HLRC) shows poor performance on lock based applications because of two reasons: (1) a whole page is fetched on a page fault while actual modification is much smaller, and (2) a home is at the fixed location while access pattern is migratory. In this paper we present an efficient lock protocol for HLRC. In this protocol, the pages that are expected to be used by acquirer are selectively updated using diffs. The diff accu-mulation problem is minimized by limiting the size of diffs to be sent for each page. Our protocol reduces the number of page faults inside critical sections because pages can be up-dated by applying locally stored diffs. This reduction yields the reduction of average lock waiting time and the reduction of message amount. The experiment with five applications shows that our protocol archives 2 %- 40 % speedup against base HLRC for four applications.