[PATCH] ARM: Add PI/robust mutexes support for SMP kernels

[cbouatmailru@gmail.com (Anton Vorontsov)]

On Mon, Jun 07, 2010 at 04:40:01PM -0400, Nicolas Pitre wrote:
> On Tue, 8 Jun 2010, Anton Vorontsov wrote:
> 
> > So, can we solve this by
> > 
> > ldrex
> > ...
> > strt newval
> >    ^ may cause exception, but doesn't clear the tag, so we're still atomic
> > strex <- clears the tag
> 
> No, you're not atomic anymore, as some other ldrex/strex might have come 
> through by the time the strt is executed, and while this strex wouldn't 
> be executed as the tag would be cleared at that point, the strt has no 
> such concerns with atomic tags and would indeed corrupt whatever new 
> value has been stored in the mean time.

Ugh, surely right you are, thanks!

It seems Catalin's "Remove the domain switching" patch comes handy
here.

-- 
Anton Vorontsov
email: cbouatmailru at gmail.com
irc://irc.freenode.net/bd2