Process, Thread

process structure
프로세스의 구조를 알아야 무엇을 공유하고 무엇을 공유하지 않는지 알 수 있다

Process?
Processes carry out tasks within the operating system. A program is a set of machine code instructions and data stored in an executable image on disk and is, as such, a passive entity; a process can be thought of as a computer program in action.

each process is represented by a task_struct data structure


State - running, waiting, zombie, Stopped
Scheduling information
Identifier - pid
Inter-Process Communication - for ipc
Links - pstree | more
Time - cpu time
File system - for VFS
Virtual memory
Context


The child is a copy of the parent. For example, the child gets a copy of the parent's data space, heap, and stack. Note that this is a copy for the child;
the parent and the child do not share these portions of memory.

The parent and the child share the text segment

Advanced Programming in the UNIX Environment
http://tldp.org/LDP/tlk/kernel/processes.html