Messages in this thread | | | Date | Fri, 20 Jul 2007 16:45:07 -0400 | From | Mathieu Desnoyers <> | Subject | Re: blackfin - cmpxchg not atomic ? |
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* Mike Frysinger (vapier.adi@gmail.com) wrote: > On 7/20/07, Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote: > >I am currently passing through each architectures adding a > >cmpxchg_local() to each system.h, and I notice that you disable > >interrupts in your cmpxchg() implementation, why are you doing so ? > > because Blackfin lacks any atomic instructions > > >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 > > >I also don't like the comment in asm-blackfin/atomic.h : > > > > * Generally we do not concern about SMP BFIN systems, so we don't have > > * to deal with that. > > > >I have seen on the blackfin website that you actually sell a board with > >SMP. Why aren't you caring about it ? > > just because a processor has more than one core does not make it SMP > -mike
I see, thanks for the reply. Is there a particular reason for implementing system.h/cmpxchg() in assembly rather that in plain C then?
-- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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