Date: Mon, 4 Dec 2017 23:57:54 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: David Howells <dhowells@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        linux-kernel@vger.kernel.org, mingo@kernel.org, jiangshanlai@gmail.com,
        dipankar@in.ibm.com, akpm@linux-foundation.org,
        mathieu.desnoyers@efficios.com, josh@joshtriplett.org,
        tglx@linutronix.de, rostedt@goodmis.org, edumazet@google.com,
        fweisbec@gmail.com, oleg@redhat.com
Subject: Re: [PATCH tip/core/rcu 01/21] doc: READ_ONCE() now implies
 smp_barrier_depends()
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On Mon, Dec 04, 2017 at 10:39:05PM +0000, David Howells wrote:
> Peter Zijlstra <peterz@infradead.org> wrote:
> 
> > > 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.
> 
> memory-barriers.txt explains how the barriers used by the kernel work, amongst
> other things.

The thing is, read-barrier-depends will no longer be used. read-read
dependencies will henceforth be assumed to 'just work'.

> Don't forget, btw, that Blackfin uses it also.

We should delete that blackfin code, its beyond insane.