Messages in this thread | | | Date | Tue, 26 Jun 2018 11:08:55 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH tip/core/rcu 16/27] rcu: Add comment documenting how rcu_seq_snap works |
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On Tue, Jun 26, 2018 at 07:14:54PM +0200, Peter Zijlstra wrote: > On Mon, Jun 25, 2018 at 05:35:02PM -0700, Paul E. McKenney wrote: > > From: "Joel Fernandes (Google)" <joel@joelfernandes.org> > > > > rcu_seq_snap may be tricky to decipher. Lets document how it works with > > an example to make it easier. > > Since you had me looking at them functions; why isn't rcu_seq_snap() > using smp_load_acquire() and rcu_seq_end() using smp_store_release() ? > Their respective comments seem to suggest that would be sufficent.
I do not believe that this would suffice. Would it make sense to refer to Documentation/RCU/Design/Memory-Ordering in the comment header?
Except that this would invite sprinkling this pathname far and wide...
The key point is that these functions are part of the any-to-any memory-ordering guarantee that RCU grace periods provide.
Thanx, Paul
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