From mboxrd@z Thu Jan  1 00:00:00 1970
From: Oleg Nesterov <oleg@redhat.com>
Subject: Re: [PATCHv5 2/2] memory barrier: adding smp_mb__after_lock
Date: Tue, 7 Jul 2009 17:44:40 +0200
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Cc: Jiri Olsa <jolsa@redhat.com>, Ingo Molnar <mingo@elte.hu>,
	Eric Dumazet <eric.dumazet@gmail.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
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	fbl@redhat.com, nhorman@redhat.com, davem@redhat.com,
	htejun@gmail.com, jarkao2@gmail.com, davidel@xmailserver.org
To: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
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On 07/07, Mathieu Desnoyers wrote:
>
> Actually, thinking about it more, to appropriately support x86, as well
> as powerpc, arm and mips, we would need something like:
>
> read_lock_smp_mb()
>
> Which would be a read_lock with an included memory barrier.

Then we need read_lock_irq_smp_mb, read_lock_irqsave__smp_mb, write_lock_xxx,
otherwise it is not clear why only read_lock() has _smp_mb() version.

The same for spin_lock_xxx...

Oleg.