kdump: quad core Opteron

[Bob Montgomery]

On Mon, 2008-12-08 at 15:56 +0000, Chandru wrote:

> Hi Bob,
> 
> This problem was recently reported on a LS42 blade and the patch given by you
> also resolved the issue here too.  However I made couple of changes to
> kexec-tools to ignore GART memory region and not have elf headers created to
> it.  This patch also seemed to work on a LS21.
> 
> Thanks,
> Chandru

Hi Chandru,

I tried your patch on kexec-tools, and I'm seeing a zero-length section
in /proc/vmcore (using readelf -e /proc/vmcore) right after the GART
hole:

/proc/iomem in the main kernel shows:
  01000000-08ffffff : Crash kernel 
  20000000-23ffffff : GART
cfe4e000-cfe55fff : ACPI Tables

And readelf -e /proc/vmcore in the kdump kernel shows:

Program Headers:
  Type           Offset             VirtAddr           PhysAddr
                 FileSiz            MemSiz              Flags  Align
...
  LOAD           0x000000000144d99c 0xffff810009000000 0x0000000009000000
                 0x0000000017000000 0x0000000017000000  RWE    0
  LOAD           0x000000001844d99c 0xffff810024000000 0x0000000024000000
                 0x00000000abe4e000 0x00000000abe4e000  RWE    0
  LOAD           0x00000000c429b99c 0xffff810024000000 0x0000000024000000
                 0x0000000000000000 0x0000000000000000  RWE    0
...

The first LOAD shown covers 09000000-20000000, the System RAM between
the Crash kernel and the GART.  
The next LOAD covers 24000000-cfe4e000, which is the System RAM between
the GART and the ACPI Tables.  So that all looks good.

Then the next LOAD is also at 24000000 with a 0 in the size fields.
I haven't had a chance to check the code yet.

Bob Montgomery