"Programs like SLOCCount can be used to inspect the Linux kernel's source code in more detail. According to this tool, the source code line count is not 9 million but exactly 6,399,191 (Source Lines of Code/SLOC), as the program doesn't count blank lines, comments and several other types of input. More than half of the lines are part of hardware drivers; the second largest chunk is the arch/ directory which contains the source code of the various architectures supported by Linux."
