On 07/30/2013 04:37 AM, Vijay Kilari wrote:

On Fri, Jul 26, 2013 at 10:38 PM, Stephen Warren [off-list ref] wrote:

...

quoted

Does a kernel that's used as the crash kernel guarantee:

* Never to re-use the memory that was used by the previous kernel, so
that the spin loop code/data won't be corrupted, ever, no matter how
long the crash recovery kernel runs.

* Not use SMP, so there's never a need to re-activate the non-boot CPUs,
which might not work if they aren't truly disabled but rather just
running a pin loop?

From cat /proc/iomem, normal kernel is executed from (0x80xxxxxx) with crash
kernel reserved 64M at 0xa0000000

80000000-bfffffff : System RAM
  80008000-805aeddf : Kernel code
  805e2000-8063e427 : Kernel data
  a0000000-a3ffffff : Crash kernel

crash kernel is loaded to reserved memory location and is executed from there.
I could confirm this from /proc/iomem when crash kernel is running

a0000000-a3efffff : System RAM
  a0008000-a05aeddf : Kernel code
  a05e2000-a063e427 : Kernel data

OK, but in the crash dump kernel, is 80008000..8063e427 reserved as
well, which would guarantee that the spin loop being executed by the
non-crash CPUs won't be corrupted?