Hi--
On 6/29/23 12:21, Eric DeVolder wrote:
>
> Signed-off-by: Eric DeVolder <eric.devolder@xxxxxxxxxx>
> Reviewed-by: Sourabh Jain <sourabhjain@xxxxxxxxxxxxx>
> Acked-by: Hari Bathini <hbathini@xxxxxxxxxxxxx>
> Acked-by: Baoquan He <bhe@xxxxxxxxxx>
> ---
> Documentation/ABI/testing/sysfs-devices-memory | 8 ++++++++
> .../ABI/testing/sysfs-devices-system-cpu | 8 ++++++++
> .../admin-guide/mm/memory-hotplug.rst | 8 ++++++++
> Documentation/core-api/cpu_hotplug.rst | 18 ++++++++++++++++++
> drivers/base/cpu.c | 16 ++++++++++++++--
> drivers/base/memory.c | 13 +++++++++++++
> include/linux/kexec.h | 8 ++++++++
> 7 files changed, 77 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/admin-guide/mm/memory-hotplug.rst b/Documentation/admin-guide/mm/memory-hotplug.rst
> index 1b02fe5807cc..eb99d79223a3 100644
> --- a/Documentation/admin-guide/mm/memory-hotplug.rst
> +++ b/Documentation/admin-guide/mm/memory-hotplug.rst
> @@ -291,6 +291,14 @@ The following files are currently defined:
> Availability depends on the CONFIG_ARCH_MEMORY_PROBE
> kernel configuration option.
> ``uevent`` read-write: generic udev file for device subsystems.
> +``crash_hotplug`` read-only: when changes to the system memory map
> + occur due to hot un/plug of memory, this file contains
> + '1' if the kernel updates the kdump capture kernel memory
> + map itself (via elfcorehdr), or '0' if userspace must update
> + the kdump capture kernel memory map.
> +
> + Availability depends on the CONFIG_MEMORY_HOTPLUG kernel
> + configuration option.
> ====================== =========================================================
Did you test build the documentation?
It looks to me like the end-of-table '=' signs line needs 3 more === to be long
enough for the text above it.
>
> .. note::
> diff --git a/Documentation/core-api/cpu_hotplug.rst b/Documentation/core-api/cpu_hotplug.rst
> index e6f5bc39cf5c..54581c501562 100644
> --- a/Documentation/core-api/cpu_hotplug.rst
> +++ b/Documentation/core-api/cpu_hotplug.rst
> @@ -741,6 +741,24 @@ will receive all events. A script like::
>
> can process the event further.
>
> +When changes to the CPUs in the system occur, the sysfs file
> +/sys/devices/system/cpu/crash_hotplug contains '1' if the kernel
> +updates the kdump capture kernel list of CPUs itself (via elfcorehdr),
> +or '0' if userspace must update the kdump capture kernel list of CPUs.
> +
> +The availability depends on the CONFIG_HOTPLUG_CPU kernel configuration
> +option.
> +
> +To skip userspace processing of CPU hot un/plug events for kdump
> +(ie the unload-then-reload to obtain a current list of CPUs), this sysfs
i.e.
> +file can be used in a udev rule as follows:
> +
> + SUBSYSTEM=="cpu", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end"
> +
> +For a cpu hot un/plug event, if the architecture supports kernel updates
CPU
for consistency
> +of the elfcorehdr (which contains the list of CPUs), then the rule skips
> +the unload-then-reload of the kdump capture kernel.
> +
> Kernel Inline Documentations Reference
> ======================================
>
Thanks.
--
~Randy
