Re: [patch] Real-Time Preemption, -RT-2.6.11-rc3-V0.7.38-01

Lee Revell
2005-03-16T18:22:12Z

On Wed, 2005-03-16 at 02:50 -0500, Steven Rostedt wrote:
>
> On Tue, 15 Mar 2005, Lee Revell wrote:
>
> > On Tue, 2005-03-15 at 13:05 -0500, Steven Rostedt wrote:
> > > Damn! The answer was right there in front of my eyes! Here's the cleanest
> > > solution. I forgot about wait_on_bit_lock. I've converted all the locks
> > > to use this instead. We probably need to get priority inheritence working
> > > on this too someday, but for now it's better than wasting memory or
> > > getting into deadlocks.
> > >
> >
> > I am still not clear on why this did not hit with earlier kernels +
> > PREEMPT_DESKTOP. Were the bitlocks introduced recently? Or was another
> > lock-break patch dropped?
> >
>
> When did you start seeing this? This code has been there as far back as
> 2.6.7 (the earliest 2.6 kernel I still have laying around) and as far
> back as Ingo's realtime-preempt-2.6.9-mm1-U10. Maybe the tracing didn't
> start picking this up till later, or that you were just lucky that no
> contention was happening on that lock.

Sometime after the RT preempt patches were rebased to mainline.

I don't see how there could be contention as I am on a UP.

Lee