Re: robust futex heap support patch

[Ingo Molnar <mingo@elte.hu>]

* david singleton <dsingleton@mvista.com> wrote:

> There is a new patch, patch-2.6.14-rt15-rf1, that adds support for 
> robust and priority inheriting pthread_mutexes on the 'heap'.

we need to go a bit slower. For now i had to remove robust-futexes from 
the -rt17 release because they broke normal (non-robust) futex support 
in -rt15. A simple mozilla startup would hang... Please send fixes 
against -rt16 and i'll try to re-add the robust futexes patch later on.  
You can find -rt16 at:

 http://people.redhat.com/mingo/realtime-preempt/older/patch-2.6.14-rt16

> The previous patches only supported either file based pthread_mutexes 
> or mmapped anonymous memory based pthread_mutexes.  This patch allows 
> pthread_mutexes to be 'malloc'ed while using the 
> PTHREAD_MUTEX_ROBUST_NP attribute or PTHREAD_PRIO_INHERIT attribute.
> 
> The patch can be found at:
> 
> http://source.mvista.com/~dsingleton

this patch looks much cleaner than the earlier one, but there's one more 
step to go: now that we've got the futex_head in every vma, why not hang 
all robust futexes to the vma, and thus get rid of ->robust_list and 
->robust_sem from struct address_space?

	Ingo