Re: [RT] bad BUG_ON in rtmutex.c

[Ingo Molnar <mingo@elte.hu>]

* Daniel Walker <dwalker@mvista.com> wrote:

> > But, as PI matures, it seems to be more and more acceptable.
> 
> 	I read an article on priority ceiling as another method of doing 
> this. Priority ceiling doesn't seem better, but at the same time I 
> can't imagine how you'd implement it in Linux, or not in a straight 
> forward way .

it's already implemented and can be done in userspace: userspace can do 
it by doing a sys_setscheduler() call when entering the critical 
section, and another one when exiting it. (PI is obviously faster 
because there the futex fastpath can be pure-userspace.)

	Ingo