public inbox for linux-arm-kernel@lists.infradead.org 
 help / color / mirror / Atom feed
From: marc.zyngier@arm•com (Marc Zyngier)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v24 0/9] arm64: add kdump support
Date: Tue, 6 Sep 2016 16:33:57 +0100	[thread overview]
Message-ID: <57CEE1E5.7040206@arm.com> (raw)
In-Reply-To: <976ca1f8-5efb-b45c-19b8-bde7bd06f5b8@caviumnetworks.com>

On 05/09/16 13:42, Manish Jaggi wrote:
> 
> 
> On 09/05/2016 01:45 PM, AKASHI Takahiro wrote:
>> [Cc: Marc]
>>
>> On Fri, Sep 02, 2016 at 06:23:25PM +0530, Manish Jaggi wrote:
>>>
>>>
>>> On 08/31/2016 11:01 AM, AKASHI Takahiro wrote:
>>>> Manish,
>>>>
>>>> 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 [1].
>>>>>>
>>>>>> To examine vmcore (/proc/vmcore) on a crash-dump kernel, you can use
>>>>>>   - crash utility (coming v7.1.6 or later) [2]
>>>>>>     (Necessary patches have already been queued in the master.)
>>>>>>
>>>>>> [1] T.B.D.
>>>>>> [2] 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 [3] for older changes:
>>>>>> [3]  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.
>>
>> I'm not sure that it is the cause, but anyway none of any cpu_pm_notifier's
>> will be called at panic. That is the reason why "maxcpus=1" should be
>> specified (for kdump on arm64).
>>
> What I meant was that since cpu_pm_notifier is not called before
> crash kernel is started, GIC Distributor/re-distributor/ITS is not
> set in quiescent state.

Which is fine, they are not expected to be in a sane state anyway
(that's what a crash is about...). The ITS now has provision to be put
in a disabled state before being reinitialized. As for GICD, it is
disabled before being reprogrammed, which should be enough.

> In my setup the GICD_CTRL[RWP] bit is not cleared in the
> crashkernels' distributor init function.

Which instance is failing? The initial one (just after the initial
disable)? Or the one called from gic_dist_config()?

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

  reply	other threads:[~2016-09-06 15:33 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-09  1:52 [PATCH v24 0/9] arm64: add kdump support AKASHI Takahiro
2016-08-09  1:52 ` [PATCH v24 1/9] arm64: kdump: reserve memory for crash dump kernel AKASHI Takahiro
2016-08-09  1:55   ` [PATCH v24 2/9] memblock: add memblock_cap_memory_range() AKASHI Takahiro
2016-08-10 16:26     ` James Morse
2016-08-09  1:56   ` [PATCH v24 3/9] arm64: limit memory regions based on DT property, usable-memory-range AKASHI Takahiro
2016-08-09  1:56     ` [PATCH v24 4/9] arm64: kdump: implement machine_crash_shutdown() AKASHI Takahiro
2016-08-09  1:56     ` [PATCH v24 5/9] arm64: kdump: add kdump support AKASHI Takahiro
2016-08-10 16:38       ` James Morse
2016-08-10 18:18         ` Pratyush Anand
2016-08-11 10:03           ` Pratyush Anand
2016-08-16 10:13             ` James Morse
2016-08-17 15:33               ` [PATCH] fixup! " James Morse
2016-08-18  7:32                 ` AKASHI Takahiro
2016-08-19  8:00                 ` Pratyush Anand
2016-08-19 13:34                   ` James Morse
2016-08-19 15:19                     ` Pratyush Anand
2016-08-18  7:15         ` [PATCH v24 5/9] " AKASHI Takahiro
2016-08-18  7:19           ` Dave Young
2016-08-19  1:26           ` AKASHI Takahiro
2016-08-19 11:22             ` Pratyush Anand
2016-08-22  1:29               ` AKASHI Takahiro
2016-08-22  7:07                 ` Pratyush Anand
2016-08-22 13:47                 ` James Morse
2016-08-23  0:38                   ` AKASHI Takahiro
2016-08-23 11:23                     ` Pratyush Anand
2016-08-24  8:04                       ` Dave Young
2016-08-24 10:25                         ` James Morse
2016-08-25  1:04                           ` Dave Young
2016-08-19 13:28             ` James Morse
2016-08-22  1:23               ` AKASHI Takahiro
2016-08-24 14:44       ` Ard Biesheuvel
2016-08-26  6:22         ` AKASHI Takahiro
2016-08-09  1:56     ` [PATCH v24 6/9] arm64: kdump: add VMCOREINFO's for user-space coredump tools AKASHI Takahiro
2016-08-09  1:56     ` [PATCH v24 7/9] arm64: kdump: enable kdump in the arm64 defconfig AKASHI Takahiro
2016-08-09  1:56     ` [PATCH v24 8/9] arm64: kdump: update a kernel doc AKASHI Takahiro
2016-08-09  1:57   ` [PATCH v24 9/9] Documentation: dt: chosen properties for arm64 kdump AKASHI Takahiro
2016-08-19 13:26     ` Rob Herring
2016-08-22  4:28       ` AKASHI Takahiro
2016-08-30 16:34         ` Rob Herring
2016-08-30 23:45           ` AKASHI Takahiro
2016-08-31  5:02             ` AKASHI Takahiro
2016-09-02 10:11               ` AKASHI Takahiro
2016-09-27 23:39       ` Mark Rutland
2016-08-09  2:04 ` [PATCH v24 0/9] arm64: add kdump support AKASHI Takahiro
2016-08-31  3:41 ` Manish Jaggi
2016-08-31  5:31   ` AKASHI Takahiro
2016-09-02 12:53     ` Manish Jaggi
2016-09-05  8:15       ` AKASHI Takahiro
2016-09-05 12:42         ` Manish Jaggi
2016-09-06 15:33           ` Marc Zyngier [this message]
2016-09-06 16:15             ` Manish Jaggi
2016-09-06 16:42               ` Marc Zyngier

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=57CEE1E5.7040206@arm.com \
    --to=marc.zyngier@arm$(echo .)com \
    --cc=linux-arm-kernel@lists$(echo .)infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox