Message-ID: <554A08CF.4000509@acm.org>
Date: Wed, 06 May 2015 07:27:59 -0500
From: Corey Minyard <minyard@acm.org>
Reply-To: minyard@acm.org
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To: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
CC: openipmi-developer@lists.sourceforge.net, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ipmi: Fix a problem that messages are not issued in run_to_completion
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On 04/28/2015 07:41 AM, Hidehiro Kawai wrote:
> Hello,
>
> (2015/04/24 22:00), Corey Minyard wrote:
>> Ah, yes, you are correct.  Queued for 4.1.  Thanks.
> Thank you for the review.
>
> By the way, I'm planning some enhancements of IPMI driver
> in panic context.  Currently, we can call panic notifiers
> before crash_kexec() by specifying crash_kexec_post_notifiers
> as a boot parameter.  By utilizing this feature, we can write
> SEL records before entering kdump process; we can save some
> information even if kdump fails.  Here, notifier calls
> shouldn't prevent the kdump process.  So, the reliability of
> panic notifier calls is very important.

I thought these were called before crash_kexec().  But if not that would
be a good enhancement.

> I noticed that there are possible infinite loops in the
> panic notifier call of IPMI driver (we assume BMC is
> unreliable).  To evict possible infinite loops, I'm considering
> introducing some retry timeout or retry count limit to the
> run_to_completion procedure.
>
> Do you have any opinions?
That's probably a good idea.  My thought was to keep trying in hopes of
getting something out, but you are probably right, a timeout after a few
minutes is probably appropriate.

-corey
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