Messages in this thread | | | Date | Mon, 02 Mar 2015 11:50:49 -0500 | From | Prarit Bhargava <> | Subject | Re: [PATCH v2 1/2] x86: mce: kexec: turn off MCE in kexec |
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On 03/02/2015 11:32 AM, Borislav Petkov wrote: > On Mon, Mar 02, 2015 at 11:33:33PM +0900, Naoya Horiguchi wrote: >> Yes, CPU offlining is one option to keep other CPUs quiet. I'm not sure why >> current kexec implementation doesn't offline the other CPUs but just doing >> cpu_relax() loop, but my guess is that in some kernel panic situation (like >> soft lockup) we want to keep CPUs' status undisturbed to make sure the bug's >> info is captured in kdump. > > Well either offlining or keeping them in the idle loop is fine - they're > not executing anything else and thus the probability of them causing an > MCE becomes disappearingly small.
Unless entering a deep C state kicks an MCE ... which we've seen with flaky hardware.
P.
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