From: Andi Kleen <andi@firstfloor.org>
To: Havard Skinnemoen <hskinnemoen@google.com>
Cc: Tony Luck <tony.luck@intel.com>, Borislav Petkov <bp@alien8.de>,
        linux-kernel@vger.kernel.org, Ewout van Bekkum <ewout@google.com>
Subject: Re: [PATCH 4/6] x86-mce: Add spinlocks to prevent duplicated MCP and CMCI reports.
References: <1404925766-32253-1-git-send-email-hskinnemoen@google.com>
	<1404925766-32253-5-git-send-email-hskinnemoen@google.com>
Date: Wed, 09 Jul 2014 13:35:28 -0700
In-Reply-To: <1404925766-32253-5-git-send-email-hskinnemoen@google.com>
	(Havard Skinnemoen's message of "Wed, 9 Jul 2014 10:09:24 -0700")
Message-ID: <87a98inucv.fsf@tassilo.jf.intel.com>
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Sender: linux-kernel-owner@vger.kernel.org

Havard Skinnemoen <hskinnemoen@google.com> writes:

> machine_check_poll() was modified to use spin_lock_irqsave independently
> per bank when a valid MCE is found to prevent duplicated MCE reports by
> the CMCI and polling methods. In the common case no MCE will be found,
> so the lock is not acquired until a valid MCE is found. The status is
> reread after the lock is acquired in case the MCE was already handled by
> a different thread. A unique spinlock is used per bank number, so
> contention should be mostly limited to non-shared banks.

This doesn't make sense. Banks are either owned by CMCI or by poll,
not by both. If you have true duplicates the bug must be somewhere else.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only
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