RE: [PATCH] Abstracted Priority Inheritance for RT

["Sven Dietrich" <sdietrich@mvista.com>]

> 
> On Thu, Jun 02, 2005 at 01:43:54AM -0400, john cooper wrote:
> > That might have been me.  The last time I looked at this 
> specifically, 
> > full transitive promotion was being done in the RT patch.  However 
> > unlike your attempt at scaling the lock scope, the RT patch had one 
> > lock which coordinated all mutex dependency traversals 
> system wide.  
> > This lock must be speculatively acquired even before we ascertain
> > transitive promotion is required.
> > 
> > So it doesn't scale as well as it could in the case of
> > large count SMP systems.  The response was that of "get
> > it to work first and then we'll get it to scale" which
> > is reasonable.
> 
> Just curious, what do you thinks about the rw-lock comments 
> from Esben in that a real rw-lock can't be deterministic ?
>

I think it can be deterministic if the number of readers is limited (to 1)