Messages in this thread | | | Date | Mon, 9 May 2011 22:59:35 +0530 | From | "K.Prasad" <> | Subject | Re: [RFC] Kdump and memory error handling |
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On Wed, May 04, 2011 at 10:39:14PM +0200, Andi Kleen wrote: > > Any thoughts/suggestions? > > My old attempts to solve this are > > Don't dump on MCE: > > http://git.kernel.org/?p=linux/kernel/git/ak/linux-mce-2.6.git;a=shortlog;h=refs/heads/mce/xpanic >
The problem we seen in avoiding a panic->crash_kexec->[coredump capture] is that the user may not have a means to know the reason for crash, unless the serial console is connected to capture and store the panic string.
Alternatively a 'slim' kdump (as described here: https://lkml.org/lkml/2011/5/4/396) would not contain meaningless data from the old memory, but inform the user about the cause of the crash. I'm intending to post some patches with a quick implementation of it soon.
> Handle dumps of corrupted memory regresions: > > http://git.kernel.org/?p=linux/kernel/git/ak/linux-mce-2.6.git;a=shortlog;h=refs/heads/mce/crashdump >
> IMHO these patches are still the right solutions for this. >
Like Vatsa had raised, the processor's behaviour upon reading (or any I/O operation) the faulty memory location isn't clearly defined (to the extent I read through System Programming Guide Part 1, Volume 3A, Chapter 15). In such a scenario, disabling MCE for the kdump kernel (which can potentially read the faulty memory) is making things hazy.
Thanks, K.Prasad
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