On Mon, 24 Mar 2008, Steven Rostedt wrote:

On Fri, 21 Mar 2008, Hiroshi Shimamoto wrote:

quoted

quoted

Is this a bug in mainline? The !PREEMPT_RT case should be as close to
mainline as possible, with no actual changes in object code. If this is
not the case, then we need to fix that.

No, this issue is in -rt only.

Hi Hiroshi,

Thanks again for reporting this. I took a deeper look into this today and
came to the conclusion that we need to get rid of both
slab_irq_disable_nort and slab_irq_disable_rt, and simply use
slab_irq_disable ;-)

This is what you patch indirectly does. I'll write up another patch to fix
this.

Actually, I'm going to take your patch.

Seems that the reason Ingo did the two separate, is that the functions
called also call the slab_irq_save, which will retake the locks in
PREEMPT_RT. If we don't release the lock, then we can deadlock.

Thanks,

-- Steve