Subject: Re: PROBLEM: first read of /dev/mcelog fails
From: Jon Masters <jonathan@jonmasters.org>
To: andi@firstfloor.org
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
In-Reply-To: <1289385151.3916.554.camel@constitution.bos.jonmasters.org>
References: <1289385151.3916.554.camel@constitution.bos.jonmasters.org>
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Organization: World Organi[sz]ation of Broken Dreams
Date: Wed, 10 Nov 2010 05:40:06 -0500
Message-ID: <1289385606.3916.555.camel@constitution.bos.jonmasters.org>
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On Wed, 2010-11-10 at 05:32 -0500, Jon Masters wrote:

> I recently took some time to look at the daemon side of mcelog. I found
> a few issues with that[0] that I will detail in a separate mail, but I
> am more concerned that in recent kernels, the first read() of the mcelog
> device performed by mcelog after boot always fails. 100% reproducible on
> several machines - mcelog client always bombs out in process() due to
> getting a "no such device" error from the kernel read attempt.
> The /dev/mcelog device exists, but the first read fails.
> 
> Can you do a fresh boot, run mcelog, and see what I mean?

(most distros won't see this because they still run mcelog in a cron
script - as mentioned in your recent paper - and ignore the error)

Thanks,

Jon.


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