linux kernel hugepages + bigger than 4k standard + page table entry on linux memory + Translation Lookaside Buffer + transparent hugepages
linux kernel stuff: + i/o subsystem stuff arond files: * "generic block layer" * "block device drivers" * i/o scheduler + memory management subsystsem * virtual memory * paging page replacement * page cache + process management subsystem * signal handling * process/thread creation and termination * process scheduler + IRQ (interrupt requests?) and dispatcher