Re: what is the state of current after an mm_fault occurs?

From: Andrew Morton
Date: Wed Jan 04 2006 - 20:47:41 EST


jeff shia <tshxiayu@xxxxxxxxx> wrote:
>
> In my opinion, the state of current should be TASK_RUNNING
> after an mm_fault occurs.But I donot know why the function of
> handle_mm_fault() set the state of current TASK_RUNNING.

It was a long time ago.. 2.4.early, perhaps.

There was a place (maybe in the select() code) where we were doing
copy_*_user() while in state TASK_INTERRUPTIBLE. And iirc there was a
place in the pagefault code which did schedule(). So we would occasionally
hit schedule() in state TASK_INTERRUPTIBLE, when we expected to be in state
TASK_RUNNING.

So we made handle_mm_fault() set TASK_RUNNING to prevent any further such
things.

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