Re: Why yield in coredump_wait? [was: Re: Resent: BUG in RT 45-01 when RT program dumps core]

[Ingo Molnar <mingo@elte.hu>]

* Steven Rostedt <rostedt@goodmis.org> wrote:

> On Thu, 2005-05-19 at 18:43 +0100, Alan Cox wrote:
> > On Iau, 2005-05-19 at 18:25, Daniel Walker wrote:
> > > I've seen a RT yield warning on this yield while running the FUSYN
> > > tests .. I can't imagine why it's there either.
> > 
> > Would it not make more sense to kick a task out of hard real time at the
> > point it begins dumping core. The core dumping sequence was never
> > something that thread intended to execute at real time priority
> > 
> 
> That's what I recommended in an earlier email.  I figured I'd wait to 
> see Ingo's response before sending him any patches.  The drop from RT 
> should probably be after the zap_threads, that way it can kill those 
> using the same mm right away.  Which also goes to say, we should get 
> rid of that yield.

i think the yield() is bogus - all of coredumping is (or ought to be) 
fully event-driven. I agree that coredumping itself does not need to run 
with RT priorities - but this does not change the fact that no kernel 
code should break if executing with RT priority.

In my tree i removed one yield() from exec.c and changed the other one 
to msleep(1).

	Ingo