An Analysis of Linux Scalability to Many Cores

This paper analyzes the scalability of seven system applications (Exim, memcached, Apache, PostgreSQL, gmake, Psearchy, and MapReduce) running on Linux on a 48- core computer. Except for gmake, all applications trigger scalability bottlenecks inside a recent Linux kernel. Using mostly standard parallel programming techniques - this paper introduces one new technique, sloppy counters - these bottlenecks can be removed from the kernel or avoided by changing the applications slightly.