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Date: Fri, 24 Mar 2017 21:15:49 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>, Dmitry Vyukov <dvyukov@google.com>,
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        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@kernel.org>,
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Subject: Re: locking/atomic: Introduce atomic_try_cmpxchg()
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On Fri, Mar 24, 2017 at 12:20:37PM -0700, Linus Torvalds wrote:
> I doubt it's a show-stopper, if only because nobody cares about UP any
> more. Not even the embedded world does.

For some obscure reason we recently introduced a variant for virt
people. Where it would need memory barriers against the hypervisor, but
having only a single vCPU not against itself.