[$] Improving control over transparent huge page use

The use of huge pages can significantly increase the performance of manyworkloads by reducing both memory-management overhead in the kernel andpressure on the system's translation lookaside buffer (TLB). The additionof transparent huge pages (THP) for the 2.6.38 kernel release in 2011caused the kernel to allocate huge pages automatically to make theirbenefits available to all workloads without any effort needed on theuser-space side. But it turns out that use of huge pages can make someworkloads slower as the result of internal memory fragmentation, so the THPfeature is often disabled. Two patch sets aimed at better targeting theuse of transparent huge pages are currently working their way through thereview process.