[PATCH v24 0/9] arm64: add kdump support
mjaggi at caviumnetworks.com
Fri Sep 2 05:53:25 PDT 2016
On 08/31/2016 11:01 AM, AKASHI Takahiro wrote:
> Thank you for testing my kdump and reporting issues.
> On Wed, Aug 31, 2016 at 09:11:52AM +0530, Manish Jaggi wrote:
>> Hi Akashi,
>> On 08/09/2016 07:22 AM, AKASHI Takahiro wrote:
>>> This patch series adds kdump support on arm64.
>>> 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 use my kdump patches .
>>> To examine vmcore (/proc/vmcore) on a crash-dump kernel, you can use
>>> - crash utility (coming v7.1.6 or later) 
>>> (Necessary patches have already been queued in the master.)
>>>  T.B.D.
>>>  https://github.com/crash-utility/crash.git
>>> Changes for v24 (Aug 9, 2016):
>>> o Rebase to Linux-4.8-rc1
>>> o Update descriptions about newly added DT proerties
>>> Changes for v23 (July 26, 2016):
>>> o Move memblock_reserve() to a single place in reserve_crashkernel()
>>> o Use cpu_park_loop() in ipi_cpu_crash_stop()
>>> o Always enforce ARCH_LOW_ADDRESS_LIMIT to the memory range of crash kernel
>>> o Re-implement fdt_enforce_memory_region() to remove non-reserve regions
>>> (for ACPI) from usable memory at crash kernel
>>> Changes for v22 (July 12, 2016):
>>> o Export "crashkernel-base" and "crashkernel-size" via device-tree,
>>> and add some descriptions about them in chosen.txt
>>> o Rename "usable-memory" to "usable-memory-range" to avoid inconsistency
>>> with powerpc's "usable-memory"
>>> o Make cosmetic changes regarding "ifdef" usage
>>> o Correct some wordings in kdump.txt
>>> Changes for v21 (July 6, 2016):
>>> o Remove kexec patches.
>>> o Rebase to arm64's for-next/core (Linux-4.7-rc4 based).
>>> o Clarify the description about kvm in kdump.txt.
>>> See the following link  for older changes:
>>>  http://lists.infradead.org/pipermail/linux-arm-kernel/2016-June/438780.html
>>> AKASHI Takahiro (8):
>>> arm64: kdump: reserve memory for crash dump kernel
>>> memblock: add memblock_cap_memory_range()
>>> arm64: limit memory regions based on DT property, usable-memory-range
>>> arm64: kdump: implement machine_crash_shutdown()
>>> arm64: kdump: add kdump support
>>> arm64: kdump: add VMCOREINFO's for user-space coredump tools
>>> arm64: kdump: enable kdump in the arm64 defconfig
>>> arm64: kdump: update a kernel doc
>>> James Morse (1):
>>> Documentation: dt: chosen properties for arm64 kdump
>>> Documentation/devicetree/bindings/chosen.txt | 45 ++++++
>>> Documentation/kdump/kdump.txt | 16 ++-
>>> arch/arm64/Kconfig | 11 ++
>>> arch/arm64/configs/defconfig | 1 +
>>> arch/arm64/include/asm/hardirq.h | 2 +-
>>> arch/arm64/include/asm/kexec.h | 41 +++++-
>>> arch/arm64/include/asm/smp.h | 2 +
>>> arch/arm64/kernel/Makefile | 1 +
>>> arch/arm64/kernel/crash_dump.c | 71 ++++++++++
>>> arch/arm64/kernel/machine_kexec.c | 67 ++++++++-
>>> arch/arm64/kernel/setup.c | 7 +-
>>> arch/arm64/kernel/smp.c | 63 +++++++++
>>> arch/arm64/mm/init.c | 202 +++++++++++++++++++++++++++
>>> include/linux/memblock.h | 1 +
>>> mm/memblock.c | 28 ++++
>>> 15 files changed, 551 insertions(+), 7 deletions(-)
>>> create mode 100644 arch/arm64/kernel/crash_dump.c
>> Couple of points
>> a) Just a note, while testing, the crashkernel reserved memory should be less than ARCH_LOW_ADDRESS_LIMIT (=arm64_dma_phys_limit).
> I think that this is a common mistake not only for kdump, but also
> for general kernels.
> Since request_standard_resources() calls alloc_bootmem_low(),
> the kernel will panic if any of usable "System RAM" is located
> above ARCH_LOW_ADDRESS_LIMIT.
> For kdump, using "crashkernel=SS" notation is a convenient way
> to avoid this issue.
>> b) Has anyone tested this on a SoC with Gicv3 ITS ?
>> Should the GICD/R be reset prior to switching to crash kernel ?
>> I am seeing lot of GICv3: RWP timeout, gone fishing while crash kernel boots.
> I've never seen this kind of messages.
> I usually do my testing on a fast model.
> "compatible" of interrupt-controller is "arm,gic-v3."
I suspect gic_cpu_pm_notifier is not being called on any of the cores prior to start of crash kernel.
We might have to call it explicitly.
> -Takahiro AKASHI
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