On Thu, Aug 13, 2015 at 11:49:28AM +0100, Will Deacon wrote: > On Wed, Aug 12, 2015 at 06:59:38PM +0100, Paul E. McKenney wrote: > > On Wed, Aug 12, 2015 at 08:43:46AM -0700, Paul E. McKenney wrote: > > > On Wed, Aug 12, 2015 at 02:44:15PM +0100, Will Deacon wrote: > > > > The generic relaxed atomics are now queued in -tip, so it would be really > > > > good to see this Documentation update land in 4.3 if at all possible. I > > > > appreciate it's late in the cycle, but it's always worth asking. > > > > > > Can't hurt to give it a try. I have set -rcu's rcu/next branch to this > > > commit, and if it passes a few day's worth of testing, I will see what > > > Ingo has to say about a pull request. > > > > > > This commit also privatizes smp_mb__after_unlock_lock() as well as > > > updating documentation. Looks like we need to strengthen powerpc's > > > locking primitives, then get rid of smp_mb__after_unlock_lock() entirely. > > > Or did that already happen and I just missed it? > > > > And just for completeness, here is the current version of that commit. > > > > Thanx, Paul > > > > ------------------------------------------------------------------------ > > > > b/Documentation/memory-barriers.txt | 71 +--------------------------------- > > b/arch/powerpc/include/asm/spinlock.h | 2 > > b/include/linux/spinlock.h | 10 ---- > > b/kernel/rcu/tree.h | 12 +++++ > > 4 files changed, 16 insertions(+), 79 deletions(-) > > > > commit 12d560f4ea87030667438a169912380be00cea4b > > Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> > > Date: Tue Jul 14 18:35:23 2015 -0700 > > > > rcu,locking: Privatize smp_mb__after_unlock_lock() > > > > RCU is the only thing that uses smp_mb__after_unlock_lock(), and is > > likely the only thing that ever will use it, so this commit makes this > > macro private to RCU. > > > > Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> > > Cc: Will Deacon <will.deacon@xxxxxxx> > > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > > Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> > > Cc: "linux-arch@xxxxxxxxxxxxxxx" <linux-arch@xxxxxxxxxxxxxxx> > > Acked-by: Will Deacon <will.deacon@xxxxxxx> > > I don't think the PowerPC spinlock change is queued anywhere (I sent it > out as a diff for discussion, but that was it). This patch doesn't rely > on that though, right? No, this patch just moves the smp_mb__after_unlock_lock() definition, it does not change the code generated. 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
