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Date: Thu, 04 May 2006 09:44:27 -0700
From: David Peterson <peterson66@llnl.gov>
Subject: Re: Problems with EDAC coexisting with BIOS
To: Tim Small <tim@buttersideup.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>,
       "Ong, Soo Keong" <soo.keong.ong@intel.com>,
       "Gross, Mark" <mark.gross@intel.com>,
       bluesmoke-devel@lists.sourceforge.net,
       LKML <linux-kernel@vger.kernel.org>,
       "Carbonari, Steven" <steven.carbonari@intel.com>,
       "Wang, Zhenyu Z" <zhenyu.z.wang@intel.com>
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> My first thought was to schedule a tasklet as part of the ECC-
specific 
> NMI handling, or are there any gotchas with doing this from within 
> an NMI handler?

Unfortunately yes.  __tasklet_schedule() uses interrupt disabling
as a synchronization mechanism.  This presents a problem since by
definition, NMIs can occur even when interrupts are disabled. 
However the NMI handling code in bluesmoke has a mechanism similar to
tasklets that is intended specifically for use by NMI handlers.