"Linux enthusiasts like to point out just how scalable the system is; Linux runs on everything from pocket-size devices to supercomputers with several thousand processors. What they talk about a little bit less is that, at the high end, the true scalability of the system is limited by the sort of workload which is run. CPU-intensive scientific computing tasks can make good use of very large systems, but database-heavy workloads do not scale nearly as well. There is a lot of interest in making big database systems work better, but it has been a challenging task. Nick Piggin appears to have come up with a logical next step in that direction, though, with a relatively straightforward set of core memory management changes.
"For some time, Linux has supported direct I/O from user space..."
