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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: Tue, 11 Aug 2015 20:09:16 +1000
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Subject: Re: [Qemu-devel] [RFC PATCH V7 00/19] Multithread TCG.
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To: Peter Maydell <peter.maydell@linaro.org>
Cc: mttcg@greensocs.com, Mark Burton <mark.burton@greensocs.com>, Alvise Rigo <a.rigo@virtualopensystems.com>, QEMU Developers <qemu-devel@nongnu.org>, Guillaume Delbergue <guillaume.delbergue@greensocs.com>, Paolo Bonzini <pbonzini@redhat.com>, Alex =?ISO-8859-1?Q?Benn=E9e?= <alex.bennee@linaro.org>, KONRAD =?ISO-8859-1?Q?Fr=E9d=E9ric?= <fred.konrad@greensocs.com>

On Tue, 2015-08-11 at 10:29 +0100, Peter Maydell wrote:
> Is it possible in some of these combinations to use the load-acquire
> and store-release instructions rather than explicit barriers?
> (ARMv8 has those, which I think should be slightly less heavyweight
> than explicit barriers everywhere, if the semantics line up.)

Possibly though I suppose starting with a simple barrier and then adding
more fine-grained ones to TCG might be a workable path. IE, it shouldn't
be too hard.

The problem of course is that not 2 architecture have exactly the same
semantics :-)

Cheers,
Ben.