Summary: they found bottlenecks in many applications and found that by implementing various code changes to the kernel, about 3000 lines worth, they could grea

Summary: they found bottlenecks in many applications and found that by implementing various code changes to the kernel, about 3000 lines worth, they could greatly improve performance on a 48-core Linux box. For instance, per-core data structures to speed access to commonly used kernel items. They also introduce a concept they call "sloppy counters" which is a per-core, reduced lock contention method of handling certain systemwide counters.