Re: Kernel panic from recent build

On Monday, May 02, 2016 05:17:49 PM Eric van Gyzen wrote:
> On 05/02/2016 16:14, Bill O'Hanlon wrote:
> > On Mon, May 2, 2016 at 3:55 PM, John Baldwin <jhb_at_freebsd.org> wrote:
> >
> >> On Monday, May 02, 2016 01:35:54 PM Bill O'Hanlon wrote:
> >>> ​
> >>>  IMG_20160502_130335.jpg
> >>> <
> >> https://drive.google.com/file/d/1dtJxTwWXfhXVUUtn1Vvpzh3laJt7AILyCg/view?usp=drive_web
> >>> ​
> >>> I'm getting the following panic from a recent (May 2, 2016) build.
> >>> panic: Duplicate local APIC ID 0
> >>>
> >>> The system is a Dell Precision T5500 with generic factory BIOS settings.
> >>> It has run previous builds without event for several years.
> >>>
> >>> I'm attaching a link to a photo of the screen for added details.
> >> Try setting 'hint.srat.0.disabled=1' at the loader prompt and then grab
> >> the output of 'acpidump -t' on your next boot.  The SRAT table used by
> >> the NUMA code appears to be corrupted by your BIOS.
> >>
> >> --
> >> John Baldwin
> >>
> >
> > That allowed me to boot.  I'm attaching the output of 'acpidump -t'.
> > Thanks!
> 
> Bill,
> 
> Do you have the time and interest to test this patch?  If so, remove the
> line that you added to /boot/loader.conf so the patch actually gets
> exercised.

This patch looks fine to me.  A shame since the SRAT is mostly correct, but
there are spurious 'enabled' entries in the table.  If we wanted to be more
forgiving, we could perhaps just warn about duplicate entries if they all
agree.  That might work for this system for APIC ID 0, but there are also
some enabled CPUs with APIC ID 1 which I bet don't exist on this system, so
that would probably result in a panic anyway.

You might try updating your BIOS if you are brave.

> Eric
> 
> 
> diff --git a/sys/x86/acpica/srat.c b/sys/x86/acpica/srat.c
> index 85f1922..1d0f73d 100644
> --- a/sys/x86/acpica/srat.c
> +++ b/sys/x86/acpica/srat.c
> _at__at_ -201,8 +201,12 _at__at_ srat_parse_entry(ACPI_SUBTABLE_HEADER *entry, void
> *arg)
>                  "enabled" : "disabled");
>          if (!(cpu->Flags & ACPI_SRAT_CPU_ENABLED))
>              break;
> -        KASSERT(!cpus[cpu->ApicId].enabled,
> -            ("Duplicate local APIC ID %u", cpu->ApicId));
> +        if (cpus[cpu->ApicId].enabled) {
> +            printf("SRAT: Duplicate local APIC ID %u\n",
> +                cpu->ApicId);
> +            *(int *)arg = ENXIO;
> +            break;
> +        }
>          cpus[cpu->ApicId].domain = domain;
>          cpus[cpu->ApicId].enabled = 1;
>          break;
> 


-- 
John Baldwin