On Tue, Jul 14, 2015 at 03:12:16PM +0100, Will Deacon wrote: > On Tue, Jul 14, 2015 at 03:00:14PM +0100, Paul E. McKenney wrote: > > On Tue, Jul 14, 2015 at 01:51:46PM +0100, Will Deacon wrote: > > > On Tue, Jul 14, 2015 at 01:45:40PM +0100, Paul E. McKenney wrote: > > > > On Tue, Jul 14, 2015 at 11:04:29AM +0100, Will Deacon wrote: > > > > > Given that RCU is currently the only user of this barrier, how would you > > > > > feel about making the barrier local to RCU and not part of the general > > > > > memory-barrier API? > > > > > > > > In theory, no objection. Your thought is to leave the definitions where > > > > they are, mark them as being used only by RCU, and removing mention from > > > > memory-barriers.txt? Or did you have something else in mind? > > > > > > Actually, I was thinking of defining them in an RCU header file with an > > > #ifdef CONFIG_POWERPC for the smb_mb() version. Then you could have a big > > > comment describing the semantics, or put that in an RCU Documentation file > > > instead of memory-barriers.txt. > > > > > > That *should* then mean we notice anybody else trying to use the barrier, > > > because they'd need to send patches to either add something equivalent > > > or move the definition out again. > > > > My concern with this approach is that someone putting together a new > > architecture might miss this. That said, this approach certainly would > > work for the current architectures. > > I don't think they're any more likely to miss it than with the current > situation where the generic code defines the macro as a NOP unless you > explicitly override it. 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
