Date: Wed, 12 Nov 2014 15:43:41 -0500 (EST)
Message-Id: <20141112.154341.1705628294274955796.davem@davemloft.net>
To: alexander.h.duyck@redhat.com
Cc: will.deacon@arm.com, alexander.duyck@gmail.com, linux-arch@vger.kernel.org,
        linux-kernel@vger.kernel.org, mikey@neuling.org, tony.luck@intel.com,
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        michael@ellerman.id.au, geert@linux-m68k.org, fweisbec@gmail.com,
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Subject: Re: [PATCH] arch: Introduce read_acquire()
From: David Miller <davem@davemloft.net>
In-Reply-To: <54627BC0.4020705@redhat.com>
References: <20141111185510.2181.75347.stgit@ahduyck-workstation.home>
	<20141111194734.GL16265@arm.com>
	<54627BC0.4020705@redhat.com>
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From: Alexander Duyck <alexander.h.duyck@redhat.com>
Date: Tue, 11 Nov 2014 13:12:32 -0800

> The architectures I need to sort out are arm, x86, sparc, ia64, and
> s390 as they are the only ones that tried to make use of the
> smp_load_acquire logic.

On sparc64, you don't have to worry about anything really.

Only mb() does anything.  The cpus execute in a reasonably strict
memory ordering mode, and that's why rmb/wmb and friends are simply
nops with a compiler barrier.
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