On Wed, Jun 16, 2010 at 05:23:15PM -0400, Mathieu Desnoyers wrote:
> * Paul E. McKenney ([email protected]) wrote:
> > Add native support for armv7l. Other variants of ARM will likely require
> > separate ports.
> >
> > Signed-off-by: Paul E. McKenney <[email protected]>
> > ---
> > configure.ac | 4 +++
> > urcu/arch_armv7l.h | 59
> > ++++++++++++++++++++++++++++++++++++++++++++
> > urcu/uatomic_arch_armv7l.h | 48 +++++++++++++++++++++++++++++++++++
[ . . . ]
> > +#ifdef __cplusplus
> > +extern "C" {
> > +#endif
> > +
> > +/* xchg */
> > +#define uatomic_xchg(addr, v) __sync_lock_test_and_set(addr, v)
> > +
> > +/* cmpxchg */
> > +#define uatomic_cmpxchg(addr, old, _new) \
> > + __sync_val_compare_and_swap(addr, old, _new)
> > +
> > +/* uatomic_add_return */
> > +#define uatomic_add_return(addr, v) __sync_add_and_fetch(addr, v)
>
> So, do we end up trusting that gcc got the memory barriers right in the ARM
> __sync_() primitives ? That sounds unlikely.
>
> I'd vote for surrounding these primitives with smp_mb().
On ARM, my current belief is that the primitives other than
__sync_synchronize() and __sync_lock_release() are set up correctly.
However, I must defer to Paolo and Uli on this.
Thanx, Paul
> Thanks,
>
> Mathieu
>
> > +
> > +#ifdef __cplusplus
> > +}
> > +#endif
> > +
> > +#include <urcu/uatomic_generic.h>
> > +
> > +#endif /* _URCU_ARCH_UATOMIC_ARMV7L_H */
> > --
> > 1.7.0.6
> >
>
> --
> Mathieu Desnoyers
> Operating System Efficiency R&D Consultant
> EfficiOS Inc.
> http://www.efficios.com
_______________________________________________
ltt-dev mailing list
[email protected]
http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
