Seonglae ChoThe main use of clone() is to implement threads
Thread PCB is more sharable PCB by option
확장성을 위해 Process Control Block 변경 최소화하고 구현되었다. Linus decided against extending the Linux kernel with threads.
child return 0, parent get child's pid
clone() flags
CLONE_VM- share Virtual Address space
CLONE_FS- share File System information
CLONE_FILES- share open File Descriptor