On Wed, May 19, 2010 at 12:54:49PM -0700, David Miller wrote: > From: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> > Date: Wed, 19 May 2010 08:01:32 -0700 > > > On Wed, May 19, 2010 at 11:03:27PM +1000, Nick Piggin wrote: > >> For atomic_read it shouldn't matter unless gcc is *really* bad at it. > >> Ah, for atomic_read, the required semantic is surely ACCESS_ONCE, so > >> that's where the volatile is needed? (maybe it would be clearer to > >> explicitly use ACCESS_ONCE?) > > > > Explicit use of ACCESS_ONCE() where needed makes a lot of sense to me, > > and allows better code to be generated for initialization and cleanup > > code where no other task has access to the atomic_t. > > I agree and I want to see this too, but I think with the tree the size > that it is we have to work backwards at this point. > > Existing behavior by default, and optimized cases get tagged by using > a new interface (atomic_read_light(), test_bit{,s}_light(), etc.) Fair enough! Thanx, Paul -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html