* Paul E. McKenney <paul...@linux.vnet.ibm.com> wrote: > On Sun, Jan 15, 2017 at 10:40:58AM +0100, Ingo Molnar wrote: > > > > * Paul E. McKenney <paul...@linux.vnet.ibm.com> wrote: > > > > > > [sounds of rummaging around in the Git tree] > > > > > > > > I found this commit of yours from ancient history (more than a year > > > > ago!): > > > > > > > > commit 12d560f4ea87030667438a169912380be00cea4b > > > > Author: Paul E. McKenney <paul...@linux.vnet.ibm.com> > > > > 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 <paul...@linux.vnet.ibm.com> > > > > Cc: Will Deacon <will.dea...@arm.com> > > > > Cc: Peter Zijlstra <pet...@infradead.org> > > > > Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> > > > > Cc: "linux-a...@vger.kernel.org" <linux-a...@vger.kernel.org> > > > > > > > > So I concur and I'm fine with your patch - or with the status quo code > > > > as well. > > > > > > I already have the patch queued, so how about I keep it if I get an ack > > > from the powerpc guys and drop it otherwise? > > > > Yeah, sounds good! Your patch made me look up 'RelAcq' so it has > > documentation > > value as well ;-) > > ;-) ;-) ;-) > > Looking forward, my guess would be that if some other code needs > smp_mb__after_unlock_lock() or if some other architecture needs > non-smb_mb() special handling, I should consider making it work the > same as smp_mb__after_atomic() and friends. Does that seem like a > reasonable thought?
Yeah, absolutely - it's just that the pattern triggered the 'this looks a bit too specialized' response in me, but after seeing the details (again ...) I agree that this time is different! Thanks, Ingo