Commit df429ac0 authored by Reza Arbab's avatar Reza Arbab Committed by Linus Torvalds
Browse files

memory-hotplug: more general validation of zone during online 

When memory is onlined, we are only able to rezone from ZONE_MOVABLE to
ZONE_KERNEL, or from (ZONE_MOVABLE - 1) to ZONE_MOVABLE.

To be more flexible, use the following criteria instead; to online
memory from zone X into zone Y,

* Any zones between X and Y must be unused.
* If X is lower than Y, the onlined memory must lie at the end of X.
* If X is higher than Y, the onlined memory must lie at the start of X.

Add zone_can_shift() to make this determination.

Link: http://lkml.kernel.org/r/1462816419-4479-3-git-send-email-arbab@linux.vnet.ibm.com


Signed-off-by: default avatarReza Arbab <arbab@linux.vnet.ibm.com>
Reviewd-by: default avatarYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrew Banman <abanman@sgi.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Zhang Zhen <zhenzhang.zhang@huawei.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e51e6c8f

include/linux/memory_hotplug.h

+2 −0
Original line number Diff line number Diff line
@@ -284,5 +284,7 @@ extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms, 
		unsigned long map_offset);

extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,

					  unsigned long pnum);

extern int zone_can_shift(unsigned long pfn, unsigned long nr_pages,

			  enum zone_type target);



#endif /* __LINUX_MEMORY_HOTPLUG_H */

mm/memory_hotplug.c

+35 −7
Original line number Diff line number Diff line
@@ -1047,6 +1047,37 @@ static void node_states_set_node(int node, struct memory_notify *arg) 
	node_set_state(node, N_MEMORY);

}



int zone_can_shift(unsigned long pfn, unsigned long nr_pages,

		   enum zone_type target)

{

	struct zone *zone = page_zone(pfn_to_page(pfn));

	enum zone_type idx = zone_idx(zone);

	int i;



	if (idx < target) {

		/* pages must be at end of current zone */

		if (pfn + nr_pages != zone_end_pfn(zone))

			return 0;



		/* no zones in use between current zone and target */

		for (i = idx + 1; i < target; i++)

			if (zone_is_initialized(zone - idx + i))

				return 0;

	}



	if (target < idx) {

		/* pages must be at beginning of current zone */

		if (pfn != zone->zone_start_pfn)

			return 0;



		/* no zones in use between current zone and target */

		for (i = target + 1; i < idx; i++)

			if (zone_is_initialized(zone - idx + i))

				return 0;

	}



	return target - idx;

}



/* Must be protected by mem_hotplug_begin() */

int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type)
@@ -1072,13 +1103,10 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ 
	    !can_online_high_movable(zone))

		return -EINVAL;



	if (online_type == MMOP_ONLINE_KERNEL &&

	    zone_idx(zone) == ZONE_MOVABLE)

		zone_shift = -1;



	if (online_type == MMOP_ONLINE_MOVABLE &&

	    zone_idx(zone) == ZONE_MOVABLE - 1)

		zone_shift = 1;

	if (online_type == MMOP_ONLINE_KERNEL)

		zone_shift = zone_can_shift(pfn, nr_pages, ZONE_NORMAL);

	else if (online_type == MMOP_ONLINE_MOVABLE)

		zone_shift = zone_can_shift(pfn, nr_pages, ZONE_MOVABLE);



	zone = move_pfn_range(zone_shift, pfn, pfn + nr_pages);

	if (!zone)

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