Linux kernel : process descriptor

Linux kernel : process descriptor

1.To manage processes, the kernel must have a clear picture of what EACH process is doing.

2. it must know, eg., the process's priority, whether it is running on a cpu or blocked on an event, what address space has been assigned ti it, which files it is allowed to address and so on.

3. This is the role of the process descriptor -- a task_struct type structure whose fields contain all the information related to a single process. ( the kernel also defines the task_t data type to be equivalent to struct task_struct.

4. In addition to a large number of fields containing process attributes, the process descriptor contains several pointers to OTHER data structures that, in turn, contain pointers to other structures.

eg.,

i) thread_info :low_level information for the process

ii) mm_struct : pointers to memory area descriptors

iii) tty_struct : tty associated with the process

iv) fs-struct : current directory

v) file_struct : pointers to file descriptors

vi) signal_struct : signals received

source :
ULK3 , page 81-82

丁望
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