Ah, I see your point. Here's the catch: Large buffer sizes only increase efficiency for sequential reads. mmap() is still much faster for random access within

Ah, I see your point. Here's the catch: Large buffer sizes only increase efficiency for sequential reads. mmap() is still much faster for random access within a file. Doubly so, because we need to not just read() but also lseek() for every read. The inefficiencies of read() can be minimized in the sequential case only.