On Wed, Mar 23, 2005 at 08:38:11PM +1100, Herbert Xu wrote: > > > ok. It's enough to put a barrier into the else branch here, because the > > atomic op in the main brain is a barrier by itself. > > Since the else branch is only taken when rcu_read_lock_nesting > 0, do > we need the barrier at all?
Actually, since atomic_inc isn't a barrier, we do need that mb. However, it should only be necessary in the main branch and we can use smp_mb__after_atomic_inc which is optimised away on a number of architectures (i386 in particular). Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} <[EMAIL PROTECTED]> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
