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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: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Wen 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Lai Jiangshan 2012-12-11 16:03:16 -08:00 committed by Linus Torvalds
parent fcf07d22f0
commit 511c2aba8f
4 changed files with 146 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
Documentation/memory-hotplug.txt
View File

@ -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.

33
drivers/base/memory.c
View File

@ -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 @@ out:
}
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;

13
include/linux/memory_hotplug.h
View File

@ -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);

100
mm/memory_hotplug.c
View File

@ -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);