On Fri, Jun 25, 2004 at 17:23:23 +0530, amith wrote:
> Dhiman, Gaurav wrote:
>
> >Hi Amith,
> >
> >Answer for your second question:
> >
> >need_resched is not something specific to a particular process and is
> >not a part of task_struct, its global to kernel and is set by timer
> >interrupt whenever the timer interrupt finds that the time allocated to
> >current process (represented by 'current' pointer) has expired.
> >
> >Your first question is my question also, How the returning code of any
> >interrupt finds whether the control is returning to user space or kernel
> >space? As far as I think, it must be checking if the return address
> >falls in kernel address range or in user address range. Can someone give
> >the detailed insight about this?
> >
> >Regards,
> >Gaurav Dhiman.
> >
> >hi Gaurav,
> >
> but i find :
>
> struct task_struct {
> .....
> ......
> volatile unsigned long need_resched;
> ....
> ....
> ...
> };
>
>
> and where is need_resched which sounds/seems to be global ?? but i
No. It is not global. It is really in task_struct. It seems, that that way
it's easier to work with it from assembly.
-------------------------------------------------------------------------------
Jan 'Bulb' Hudec <bulb@ucw.cz>
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