Re: blackfin - cmpxchg not atomic ?

[Mike Frysinger]

On 7/21/07, Robert Schwebel <r.schwebel@xxxxxxxxxxxxxx> wrote:
> On Fri, Jul 20, 2007 at 04:36:12PM -0400, Mike Frysinger wrote:
> > > Also, does you assembly stub _really_ modify memory atomically ? If yes,
> > > then there should be no need for disabling interrupts. Else, I see a
> > > major problem with SMP.
> >
> > that isnt the only problem with SMP on Blackfin
>
> Could you ealborate?

i'm pretty sure there's already been a thread on LKML about it ... the
fact that our parts currently lack any sort of cache snooping or
control over any other is a huge issue.

we've contracted a company to do SMP, but it'll have quite a bit of
overhead since it'll need to do a lot of communication/message passing
between cores to account for these hardware deficiencies.
-mike
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