Hi,

On 09/07/2016 07:29 AM, AKASHI Takahiro wrote:

     v26-specific note: After a comment from Rob[0], an idea of adding
     "linux,usable-memory-range" was dropped. Instead, an existing
     "reserved-memory" node will be used to limit usable memory ranges
     on crash dump kernel.
     This works not only on UEFI/ACPI systems but also on DT-only systems,
     but if he really insists on using DT-specific "usable-memory" property,
     I will post additional patches for kexec-tools. Those would be
     redundant, though.
     Even in that case, the kernel will not have to be changed.

This patch series adds kdump support on arm64.
There are some prerequisite patches [1],[2].

To load a crash-dump kernel to the systems, a series of patches to
kexec-tools, which have not yet been merged upstream, are needed.
Please always use my latest kdump patches, v3 [3].

To examine vmcore (/proc/vmcore) on a crash-dump kernel, you can use
   - crash utility (coming v7.1.6 or later) [4]
     (Necessary patches have already been queued in the master.)


[0] http://lists.infradead.org/pipermail/linux-arm-kernel/2016-August/452582.html
[1] "arm64: mark reserved memblock regions explicitly in iomem"
     http://lists.infradead.org/pipermail/linux-arm-kernel/2016-August/450433.html
[2] "efi: arm64: treat regions with WT/WC set but WB cleared as memory"
     http://lists.infradead.org/pipermail/linux-arm-kernel/2016-August/451491.html
[3] T.B.D.
[4] https://github.com/crash-utility/crash.git

Are you going to rebase your patch series onto v4.9-rc1 tag soon? I see
that patches [1] and [2] are already in v4.9-rc1, but when tried to apply
this series, I've got conflict on first patch of the series ("arm64: kdump:
reserve memory for crash dump kernel"). I want to try arm64 kdump
patches again on my board, so I'm interested in this. The question is
whether I need to rebase it myself or you will do the same (and address
comments) soon.

Also I see Geoff published v6 of arm64 kexec-tools patches, so same
question is applicable to "(kexec-tools) arm64: add kdump support"
patch series.

Thanks,
Ruslan