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Date: Thu, 9 Mar 2006 18:41:04 +1100
From: Paul Mackerras <paulus@samba.org>
Subject: Re: [PATCH] Document Linux's memory barriers [try #2]
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To: Jesse Barnes <jbarnes@virtuousgeek.org>
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Jesse Barnes writes:

> Hm, a static checker should be able to find this stuff, shouldn't it?

Good idea.  I wonder if sparse could be extended to do it.

Alternatively, it wouldn't be hard to check dynamically.  Just have a
per-cpu count of outstanding MMIO stores.  Zero it in spin_lock and
mmiowb, increment it in write*, and grizzle if spin_unlock finds it
non-zero.  Should be very little overhead.

Paul.