A couple of SMP deadlock patches

[Maxim Maximov]

John Baldwin wrote:
> Included below are two patches for two different potential deadlocks on SMP.  
> The first one I have sent to the list before, but it didn't seem to help 
> anyone.  I do believe it is a fix for a possible deadlock though so I'd like 
> some more testing feedback with the aim of committing it.  The second patch 
> works around a lock order reversal introduced with the sleep queue code 
> (since sched_lock's scope was reduced) at the expense of increasing the 
> latency between a swapped out thread becoming runnable and the swapper waking 
> up to swap the process back in.

I'm sorry, but for me PREEMPTION defined in kernel with these patches is 
still causing deadlocks. SMP, HTT enabled.

-- 
Maxim Maximov