Re: Query regarding Linuc Kernel Threads

[Devesh Agrawal <devesh.agrawal@xxxxxxxxx>]

Hi,
So how do you create threads in linux, ie threads that share the same
address space. ?, Does the function kernel_thread do the job ?
-Devesh

On Apr 1, 2005 10:45 AM, lk <linux_kernel@xxxxxxxxx> wrote:
> |I have a query about linux process and thread model.
> |Every process has a 8KB of kernel stack, out of which
> |some 960 bytes are reserved for task_struct. Now,
> |task_struct uniquely identifies a process.
> 
> Correct, for Linux process and threads are identical and every process (or
> thread) has its own task_struct. every process is a child to some other
> process except for init. threads differs only in the sense that the share
> process address space.
> 
> |That means,if any kernel thread of currently running process
> |wants to access task_struct of the process, then it
> |has to retrieve the corresponding task_struct by
> |manipulating esp register, since task_struct lies at
> |the bottom of the stack area allocated to every
> |process. Now, above scenario is only possible if all
> |the kernel threads of currently running process share
> |the same kernel stack area allocated to the process.
> |Is this true that kernel threads share kernel stack
> |area allocated to a process?
> 
> since every process has its own task_strct and hence own kernel stack. if a
> thread wants to access its parent process's task struct it should  make use
> of task_struct->parent.
> 
> regards
> lk
> 
> 
> --
> Kernelnewbies: Help each other learn about the Linux kernel.
> Archive:       http://mail.nl.linux.org/kernelnewbies/
> FAQ:           http://kernelnewbies.org/faq/
> 
> 


-- 
Devesh Agrawal
==============
The program is absolutely right; 
therefore the computer must be wrong.
-----------------
How an engineer writes a program: 
Start by debugging an empty file...
----------------------
Systems programmers are the high priests of a low cult.  - R. S. Barton

--
Kernelnewbies: Help each other learn about the Linux kernel.
Archive:       http://mail.nl.linux.org/kernelnewbies/
FAQ:           http://kernelnewbies.org/faq/