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Commit 511c2aba authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Linus Torvalds
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mm, memory-hotplug: dynamic configure movable memory and portion memory 



Add online_movable and online_kernel for logic memory hotplug.  This is
the dynamic version of "movablecore" & "kernelcore".

We have the same reason to introduce it as to introduce "movablecore" &
"kernelcore".  It has the same motive as "movablecore" & "kernelcore", but
it is dynamic/running-time:

o We can configure memory as kernelcore or movablecore after boot.

  Userspace workload is increased, we need more hugepage, we can't use
  "online_movable" to add memory and allow the system use more
  THP(transparent-huge-page), vice-verse when kernel workload is increase.

  Also help for virtualization to dynamic configure host/guest's memory,
  to save/(reduce waste) memory.

  Memory capacity on Demand

o When a new node is physically online after boot, we need to use
  "online_movable" or "online_kernel" to configure/portion it as we
  expected when we logic-online it.

  This configuration also helps for physically-memory-migrate.

o all benefit as the same as existed "movablecore" & "kernelcore".

o Preparing for movable-node, which is very important for power-saving,
  hardware partitioning and high-available-system(hardware fault
  management).

(Note, we don't introduce movable-node here.)

Action behavior:
When a memoryblock/memorysection is onlined by "online_movable", the kernel
will not have directly reference to the page of the memoryblock,
thus we can remove that memory any time when needed.

When it is online by "online_kernel", the kernel can use it.
When it is online by "online", the zone type doesn't changed.

Current constraints:
Only the memoryblock which is adjacent to the ZONE_MOVABLE
can be online from ZONE_NORMAL to ZONE_MOVABLE.

[akpm@linux-foundation.org: use min_t, cleanups]
Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: default avatarWen Congyang <wency@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent fcf07d22

Documentation/memory-hotplug.txt

+13 −1
Original line number Diff line number Diff line
@@ -161,7 +161,8 @@ a recent addition and not present on older kernels. 
		    in the memory block.

'state'           : read-write

                    at read:  contains online/offline state of memory.

                    at write: user can specify "online", "offline" command

                    at write: user can specify "online_kernel",

                    "online_movable", "online", "offline" command

                    which will be performed on al sections in the block.

'phys_device'     : read-only: designed to show the name of physical memory

                    device.  This is not well implemented now.
@@ -255,6 +256,17 @@ For onlining, you have to write "online" to the section's state file as: 


% echo online > /sys/devices/system/memory/memoryXXX/state



This onlining will not change the ZONE type of the target memory section,

If the memory section is in ZONE_NORMAL, you can change it to ZONE_MOVABLE:



% echo online_movable > /sys/devices/system/memory/memoryXXX/state

(NOTE: current limit: this memory section must be adjacent to ZONE_MOVABLE)



And if the memory section is in ZONE_MOVABLE, you can change it to ZONE_NORMAL:



% echo online_kernel > /sys/devices/system/memory/memoryXXX/state

(NOTE: current limit: this memory section must be adjacent to ZONE_NORMAL)



After this, section memoryXXX's state will be 'online' and the amount of

available memory will be increased.

drivers/base/memory.c

+22 −11
Original line number Diff line number Diff line
@@ -254,7 +254,7 @@ static bool pages_correctly_reserved(unsigned long start_pfn, 
 * OK to have direct references to sparsemem variables in here.

 */

static int

memory_block_action(unsigned long phys_index, unsigned long action)

memory_block_action(unsigned long phys_index, unsigned long action, int online_type)

{

	unsigned long start_pfn;

	unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
@@ -269,7 +269,7 @@ memory_block_action(unsigned long phys_index, unsigned long action) 
			if (!pages_correctly_reserved(start_pfn, nr_pages))

				return -EBUSY;



			ret = online_pages(start_pfn, nr_pages);

			ret = online_pages(start_pfn, nr_pages, online_type);

			break;

		case MEM_OFFLINE:

			ret = offline_pages(start_pfn, nr_pages);
@@ -284,7 +284,8 @@ memory_block_action(unsigned long phys_index, unsigned long action) 
}



static int __memory_block_change_state(struct memory_block *mem,

		unsigned long to_state, unsigned long from_state_req)

		unsigned long to_state, unsigned long from_state_req,

		int online_type)

{

	int ret = 0;
@@ -296,7 +297,7 @@ static int __memory_block_change_state(struct memory_block *mem, 
	if (to_state == MEM_OFFLINE)

		mem->state = MEM_GOING_OFFLINE;



	ret = memory_block_action(mem->start_section_nr, to_state);

	ret = memory_block_action(mem->start_section_nr, to_state, online_type);



	if (ret) {

		mem->state = from_state_req;
@@ -319,12 +320,14 @@ static int __memory_block_change_state(struct memory_block *mem, 
}



static int memory_block_change_state(struct memory_block *mem,

		unsigned long to_state, unsigned long from_state_req)

		unsigned long to_state, unsigned long from_state_req,

		int online_type)

{

	int ret;



	mutex_lock(&mem->state_mutex);

	ret = __memory_block_change_state(mem, to_state, from_state_req);

	ret = __memory_block_change_state(mem, to_state, from_state_req,

					  online_type);

	mutex_unlock(&mem->state_mutex);



	return ret;
@@ -338,10 +341,18 @@ store_mem_state(struct device *dev, 


	mem = container_of(dev, struct memory_block, dev);



	if (!strncmp(buf, "online", min((int)count, 6)))

		ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);

	else if(!strncmp(buf, "offline", min((int)count, 7)))

		ret = memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE);

	if (!strncmp(buf, "online_kernel", min_t(int, count, 13)))

		ret = memory_block_change_state(mem, MEM_ONLINE,

						MEM_OFFLINE, ONLINE_KERNEL);

	else if (!strncmp(buf, "online_movable", min_t(int, count, 14)))

		ret = memory_block_change_state(mem, MEM_ONLINE,

						MEM_OFFLINE, ONLINE_MOVABLE);

	else if (!strncmp(buf, "online", min_t(int, count, 6)))

		ret = memory_block_change_state(mem, MEM_ONLINE,

						MEM_OFFLINE, ONLINE_KEEP);

	else if(!strncmp(buf, "offline", min_t(int, count, 7)))

		ret = memory_block_change_state(mem, MEM_OFFLINE,

						MEM_ONLINE, -1);



	if (ret)

		return ret;
@@ -676,7 +687,7 @@ int offline_memory_block(struct memory_block *mem) 


	mutex_lock(&mem->state_mutex);

	if (mem->state != MEM_OFFLINE)

		ret = __memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE);

		ret = __memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE, -1);

	mutex_unlock(&mem->state_mutex);



	return ret;

include/linux/memory_hotplug.h

+12 −1
Original line number Diff line number Diff line
@@ -26,6 +26,13 @@ enum { 
	MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE = NODE_INFO,

};



/* Types for control the zone type of onlined memory */

enum {

	ONLINE_KEEP,

	ONLINE_KERNEL,

	ONLINE_MOVABLE,

};



/*

 * pgdat resizing functions

 */
@@ -46,6 +53,10 @@ void pgdat_resize_init(struct pglist_data *pgdat) 
}

/*

 * Zone resizing functions

 *

 * Note: any attempt to resize a zone should has pgdat_resize_lock()

 * zone_span_writelock() both held. This ensure the size of a zone

 * can't be changed while pgdat_resize_lock() held.

 */

static inline unsigned zone_span_seqbegin(struct zone *zone)

{
@@ -71,7 +82,7 @@ extern int zone_grow_free_lists(struct zone *zone, unsigned long new_nr_pages); 
extern int zone_grow_waitqueues(struct zone *zone, unsigned long nr_pages);

extern int add_one_highpage(struct page *page, int pfn, int bad_ppro);

/* VM interface that may be used by firmware interface */

extern int online_pages(unsigned long, unsigned long);

extern int online_pages(unsigned long, unsigned long, int);

extern void __offline_isolated_pages(unsigned long, unsigned long);



typedef void (*online_page_callback_t)(struct page *page);

mm/memory_hotplug.c

+99 −1
Original line number Diff line number Diff line
@@ -214,6 +214,88 @@ static void grow_zone_span(struct zone *zone, unsigned long start_pfn, 
	zone_span_writeunlock(zone);

}



static void resize_zone(struct zone *zone, unsigned long start_pfn,

		unsigned long end_pfn)

{

	zone_span_writelock(zone);



	zone->zone_start_pfn = start_pfn;

	zone->spanned_pages = end_pfn - start_pfn;



	zone_span_writeunlock(zone);

}



static void fix_zone_id(struct zone *zone, unsigned long start_pfn,

		unsigned long end_pfn)

{

	enum zone_type zid = zone_idx(zone);

	int nid = zone->zone_pgdat->node_id;

	unsigned long pfn;



	for (pfn = start_pfn; pfn < end_pfn; pfn++)

		set_page_links(pfn_to_page(pfn), zid, nid, pfn);

}



static int move_pfn_range_left(struct zone *z1, struct zone *z2,

		unsigned long start_pfn, unsigned long end_pfn)

{

	unsigned long flags;



	pgdat_resize_lock(z1->zone_pgdat, &flags);



	/* can't move pfns which are higher than @z2 */

	if (end_pfn > z2->zone_start_pfn + z2->spanned_pages)

		goto out_fail;

	/* the move out part mast at the left most of @z2 */

	if (start_pfn > z2->zone_start_pfn)

		goto out_fail;

	/* must included/overlap */

	if (end_pfn <= z2->zone_start_pfn)

		goto out_fail;



	resize_zone(z1, z1->zone_start_pfn, end_pfn);

	resize_zone(z2, end_pfn, z2->zone_start_pfn + z2->spanned_pages);



	pgdat_resize_unlock(z1->zone_pgdat, &flags);



	fix_zone_id(z1, start_pfn, end_pfn);



	return 0;

out_fail:

	pgdat_resize_unlock(z1->zone_pgdat, &flags);

	return -1;

}



static int move_pfn_range_right(struct zone *z1, struct zone *z2,

		unsigned long start_pfn, unsigned long end_pfn)

{

	unsigned long flags;



	pgdat_resize_lock(z1->zone_pgdat, &flags);



	/* can't move pfns which are lower than @z1 */

	if (z1->zone_start_pfn > start_pfn)

		goto out_fail;

	/* the move out part mast at the right most of @z1 */

	if (z1->zone_start_pfn + z1->spanned_pages >  end_pfn)

		goto out_fail;

	/* must included/overlap */

	if (start_pfn >= z1->zone_start_pfn + z1->spanned_pages)

		goto out_fail;



	resize_zone(z1, z1->zone_start_pfn, start_pfn);

	resize_zone(z2, start_pfn, z2->zone_start_pfn + z2->spanned_pages);



	pgdat_resize_unlock(z1->zone_pgdat, &flags);



	fix_zone_id(z2, start_pfn, end_pfn);



	return 0;

out_fail:

	pgdat_resize_unlock(z1->zone_pgdat, &flags);

	return -1;

}



static void grow_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn,

			    unsigned long end_pfn)

{
@@ -508,7 +590,7 @@ static void node_states_set_node(int node, struct memory_notify *arg) 
}





int __ref online_pages(unsigned long pfn, unsigned long nr_pages)

int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type)

{

	unsigned long onlined_pages = 0;

	struct zone *zone;
@@ -525,6 +607,22 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages) 
	 */

	zone = page_zone(pfn_to_page(pfn));



	if (online_type == ONLINE_KERNEL && zone_idx(zone) == ZONE_MOVABLE) {

		if (move_pfn_range_left(zone - 1, zone, pfn, pfn + nr_pages)) {

			unlock_memory_hotplug();

			return -1;

		}

	}

	if (online_type == ONLINE_MOVABLE && zone_idx(zone) == ZONE_MOVABLE - 1) {

		if (move_pfn_range_right(zone, zone + 1, pfn, pfn + nr_pages)) {

			unlock_memory_hotplug();

			return -1;

		}

	}



	/* Previous code may changed the zone of the pfn range */

	zone = page_zone(pfn_to_page(pfn));



	arg.start_pfn = pfn;

	arg.nr_pages = nr_pages;

	node_states_check_changes_online(nr_pages, zone, &arg);