Re: [PATCH v2] x86/mce: Don't participate in rendezvous process once nmi_shootdown_cpus() was made

From	Xunlei Pang <xpang@redhat.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2] x86/mce: Don't participate in rendezvous process once nmi_shootdown_cpus() was made
Date	2017-02-21 02:30 +0100
Message-ID	<td7rb-3WI-7@gated-at.bofh.it> (permalink)
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On 02/21/2017 at 04:26 AM, Borislav Petkov wrote:
> On Mon, Feb 20, 2017 at 09:29:24PM +0800, Xunlei Pang wrote:
>> There is a small window between crash and kdump kernel boot, so
>> if a SRAO comes within this window it will also cause the mce
>> synchronization problem on the crashing cpu if we don't bail out the
>> crashing cpu.
> You mean, in the window between, kdump kernel starts writing out memory
> and the second, kexec-ed kernel?

Not kdump kernel starts dumping, just during nmi_shootdown_cpus(), if some
MCE comes after crashing_cpu was set and we don't skip crashing_cpu, then
the crashing cpu will enter mce handler and trigger the synchronization issue.

>
> If so, please add that information to the place in do_machine_check()
> where we check crashing_cpu so that we know why we're doing this
> temporary ignore of #MC.

Ok, will add, thanks for the feedback.

Regards,
Xunlei

Thread

[PATCH v2] x86/mce: Don't participate in rendezvous process once nmi_shootdown_cpus() was made Xunlei Pang <xlpang@redhat.com> - 2017-02-20 07:10 +0100
  Re: [PATCH v2] x86/mce: Don't participate in rendezvous process once  nmi_shootdown_cpus() was made Borislav Petkov <bp@alien8.de> - 2017-02-20 12:20 +0100
    Re: [PATCH v2] x86/mce: Don't participate in rendezvous process once  nmi_shootdown_cpus() was made Xunlei Pang <xpang@redhat.com> - 2017-02-20 14:30 +0100
      Re: [PATCH v2] x86/mce: Don't participate in rendezvous process once  nmi_shootdown_cpus() was made Borislav Petkov <bp@alien8.de> - 2017-02-20 21:30 +0100
        Re: [PATCH v2] x86/mce: Don't participate in rendezvous process once  nmi_shootdown_cpus() was made Xunlei Pang <xpang@redhat.com> - 2017-02-21 02:30 +0100
          Re: [PATCH v2] x86/mce: Don't participate in rendezvous process once  nmi_shootdown_cpus() was made Borislav Petkov <bp@alien8.de> - 2017-02-21 09:50 +0100
      Re: [PATCH v2] x86/mce: Don't participate in rendezvous process once  nmi_shootdown_cpus() was made Xunlei Pang <xpang@redhat.com> - 2017-02-21 02:30 +0100
    Re: [PATCH v2] x86/mce: Don't participate in rendezvous process once  nmi_shootdown_cpus() was made Xunlei Pang <xpang@redhat.com> - 2017-02-21 13:40 +0100
      Re: [PATCH v2] x86/mce: Don't participate in rendezvous process once  nmi_shootdown_cpus() was made Borislav Petkov <bp@alien8.de> - 2017-02-21 18:30 +0100

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