On Mon, Dec 04, 2017 at 10:52:15AM -0800, Paul E. McKenney wrote: > On Mon, Dec 04, 2017 at 03:38:56PM +0000, David Howells wrote: > > Paul E. McKenney <[email protected]> wrote: > > > > > - Q = READ_ONCE(P); smp_read_barrier_depends(); D = READ_ONCE(*Q); > > > + Q = READ_ONCE(P); D = READ_ONCE(*Q); > > > > > > the CPU will issue the following memory operations: > > > > > > Q = LOAD P, D = LOAD *Q > > > > The CPU may now issue two barriers in addition to the loads, so should we > > show > > this? E.g.: > > > > Q = LOAD P, BARRIER, D = LOAD *Q, BARRIER > > Good point! How about as shown in the updated patch below?
Humm, I thought the idea was to completely remove read_barrier_depends from the lkmm and memory-barriers.txt, making it an Alpha implementation detail.
