Re: [PATCH 1/2] docs/core-api: rename memory-hotplug-notifier to memory-hotplug

[David Hildenbrand <david@redhat.com>]

On 11/10/2018 06:58, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@linux.vnet.ibm.com>
> 
> to allow additions of new documentation about memory hotplug under the same
> roof.
> 
> Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
> ---
>  Documentation/core-api/index.rst                   |  2 +-
>  Documentation/core-api/memory-hotplug-notifier.rst | 84 ---------------------
>  Documentation/core-api/memory-hotplug.rst          | 87 ++++++++++++++++++++++
>  3 files changed, 88 insertions(+), 85 deletions(-)
>  delete mode 100644 Documentation/core-api/memory-hotplug-notifier.rst
>  create mode 100644 Documentation/core-api/memory-hotplug.rst
> 
> diff --git a/Documentation/core-api/index.rst b/Documentation/core-api/index.rst
> index 4f8a426..29c790f 100644
> --- a/Documentation/core-api/index.rst
> +++ b/Documentation/core-api/index.rst
> @@ -32,7 +32,7 @@ Core utilities
>     gfp_mask-from-fs-io
>     timekeeping
>     boot-time-mm
> -   memory-hotplug-notifier
> +   memory-hotplug
>  
>  
>  Interfaces for kernel debugging
> diff --git a/Documentation/core-api/memory-hotplug-notifier.rst b/Documentation/core-api/memory-hotplug-notifier.rst
> deleted file mode 100644
> index 35347cc..0000000
> --- a/Documentation/core-api/memory-hotplug-notifier.rst
> +++ /dev/null
> @@ -1,84 +0,0 @@
> -.. _memory_hotplug_notifier:
> -
> -=============================
> -Memory hotplug event notifier
> -=============================
> -
> -Hotplugging events are sent to a notification queue.
> -
> -There are six types of notification defined in ``include/linux/memory.h``:
> -
> -MEM_GOING_ONLINE
> -  Generated before new memory becomes available in order to be able to
> -  prepare subsystems to handle memory. The page allocator is still unable
> -  to allocate from the new memory.
> -
> -MEM_CANCEL_ONLINE
> -  Generated if MEM_GOING_ONLINE fails.
> -
> -MEM_ONLINE
> -  Generated when memory has successfully brought online. The callback may
> -  allocate pages from the new memory.
> -
> -MEM_GOING_OFFLINE
> -  Generated to begin the process of offlining memory. Allocations are no
> -  longer possible from the memory but some of the memory to be offlined
> -  is still in use. The callback can be used to free memory known to a
> -  subsystem from the indicated memory block.
> -
> -MEM_CANCEL_OFFLINE
> -  Generated if MEM_GOING_OFFLINE fails. Memory is available again from
> -  the memory block that we attempted to offline.
> -
> -MEM_OFFLINE
> -  Generated after offlining memory is complete.
> -
> -A callback routine can be registered by calling::
> -
> -  hotplug_memory_notifier(callback_func, priority)
> -
> -Callback functions with higher values of priority are called before callback
> -functions with lower values.
> -
> -A callback function must have the following prototype::
> -
> -  int callback_func(
> -    struct notifier_block *self, unsigned long action, void *arg);
> -
> -The first argument of the callback function (self) is a pointer to the block
> -of the notifier chain that points to the callback function itself.
> -The second argument (action) is one of the event types described above.
> -The third argument (arg) passes a pointer of struct memory_notify::
> -
> -	struct memory_notify {
> -		unsigned long start_pfn;
> -		unsigned long nr_pages;
> -		int status_change_nid_normal;
> -		int status_change_nid_high;
> -		int status_change_nid;
> -	}
> -
> -- start_pfn is start_pfn of online/offline memory.
> -- nr_pages is # of pages of online/offline memory.
> -- status_change_nid_normal is set node id when N_NORMAL_MEMORY of nodemask
> -  is (will be) set/clear, if this is -1, then nodemask status is not changed.
> -- status_change_nid_high is set node id when N_HIGH_MEMORY of nodemask
> -  is (will be) set/clear, if this is -1, then nodemask status is not changed.
> -- status_change_nid is set node id when N_MEMORY of nodemask is (will be)
> -  set/clear. It means a new(memoryless) node gets new memory by online and a
> -  node loses all memory. If this is -1, then nodemask status is not changed.
> -
> -  If status_changed_nid* >= 0, callback should create/discard structures for the
> -  node if necessary.
> -
> -The callback routine shall return one of the values
> -NOTIFY_DONE, NOTIFY_OK, NOTIFY_BAD, NOTIFY_STOP
> -defined in ``include/linux/notifier.h``
> -
> -NOTIFY_DONE and NOTIFY_OK have no effect on the further processing.
> -
> -NOTIFY_BAD is used as response to the MEM_GOING_ONLINE, MEM_GOING_OFFLINE,
> -MEM_ONLINE, or MEM_OFFLINE action to cancel hotplugging. It stops
> -further processing of the notification queue.
> -
> -NOTIFY_STOP stops further processing of the notification queue.
> diff --git a/Documentation/core-api/memory-hotplug.rst b/Documentation/core-api/memory-hotplug.rst
> new file mode 100644
> index 0000000..a99f2f2
> --- /dev/null
> +++ b/Documentation/core-api/memory-hotplug.rst
> @@ -0,0 +1,87 @@
> +.. _memory_hotplug:
> +
> +==============
> +Memory hotplug
> +==============
> +
> +Memory hotplug event notifier
> +=============================
> +
> +Hotplugging events are sent to a notification queue.
> +
> +There are six types of notification defined in ``include/linux/memory.h``:
> +
> +MEM_GOING_ONLINE
> +  Generated before new memory becomes available in order to be able to
> +  prepare subsystems to handle memory. The page allocator is still unable
> +  to allocate from the new memory.
> +
> +MEM_CANCEL_ONLINE
> +  Generated if MEM_GOING_ONLINE fails.
> +
> +MEM_ONLINE
> +  Generated when memory has successfully brought online. The callback may
> +  allocate pages from the new memory.
> +
> +MEM_GOING_OFFLINE
> +  Generated to begin the process of offlining memory. Allocations are no
> +  longer possible from the memory but some of the memory to be offlined
> +  is still in use. The callback can be used to free memory known to a
> +  subsystem from the indicated memory block.
> +
> +MEM_CANCEL_OFFLINE
> +  Generated if MEM_GOING_OFFLINE fails. Memory is available again from
> +  the memory block that we attempted to offline.
> +
> +MEM_OFFLINE
> +  Generated after offlining memory is complete.
> +
> +A callback routine can be registered by calling::
> +
> +  hotplug_memory_notifier(callback_func, priority)
> +
> +Callback functions with higher values of priority are called before callback
> +functions with lower values.
> +
> +A callback function must have the following prototype::
> +
> +  int callback_func(
> +    struct notifier_block *self, unsigned long action, void *arg);
> +
> +The first argument of the callback function (self) is a pointer to the block
> +of the notifier chain that points to the callback function itself.
> +The second argument (action) is one of the event types described above.
> +The third argument (arg) passes a pointer of struct memory_notify::
> +
> +	struct memory_notify {
> +		unsigned long start_pfn;
> +		unsigned long nr_pages;
> +		int status_change_nid_normal;
> +		int status_change_nid_high;
> +		int status_change_nid;
> +	}
> +
> +- start_pfn is start_pfn of online/offline memory.
> +- nr_pages is # of pages of online/offline memory.
> +- status_change_nid_normal is set node id when N_NORMAL_MEMORY of nodemask
> +  is (will be) set/clear, if this is -1, then nodemask status is not changed.
> +- status_change_nid_high is set node id when N_HIGH_MEMORY of nodemask
> +  is (will be) set/clear, if this is -1, then nodemask status is not changed.
> +- status_change_nid is set node id when N_MEMORY of nodemask is (will be)
> +  set/clear. It means a new(memoryless) node gets new memory by online and a
> +  node loses all memory. If this is -1, then nodemask status is not changed.
> +
> +  If status_changed_nid* >= 0, callback should create/discard structures for the
> +  node if necessary.
> +
> +The callback routine shall return one of the values
> +NOTIFY_DONE, NOTIFY_OK, NOTIFY_BAD, NOTIFY_STOP
> +defined in ``include/linux/notifier.h``
> +
> +NOTIFY_DONE and NOTIFY_OK have no effect on the further processing.
> +
> +NOTIFY_BAD is used as response to the MEM_GOING_ONLINE, MEM_GOING_OFFLINE,
> +MEM_ONLINE, or MEM_OFFLINE action to cancel hotplugging. It stops
> +further processing of the notification queue.
> +
> +NOTIFY_STOP stops further processing of the notification queue.
> 

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 

Thanks,

David / dhildenb