2 * linux/mm/memory_hotplug.c
7 #include <linux/stddef.h>
9 #include <linux/swap.h>
10 #include <linux/interrupt.h>
11 #include <linux/pagemap.h>
12 #include <linux/bootmem.h>
13 #include <linux/compiler.h>
14 #include <linux/export.h>
15 #include <linux/pagevec.h>
16 #include <linux/writeback.h>
17 #include <linux/slab.h>
18 #include <linux/sysctl.h>
19 #include <linux/cpu.h>
20 #include <linux/memory.h>
21 #include <linux/memory_hotplug.h>
22 #include <linux/highmem.h>
23 #include <linux/vmalloc.h>
24 #include <linux/ioport.h>
25 #include <linux/delay.h>
26 #include <linux/migrate.h>
27 #include <linux/page-isolation.h>
28 #include <linux/pfn.h>
29 #include <linux/suspend.h>
30 #include <linux/mm_inline.h>
31 #include <linux/firmware-map.h>
33 #include <asm/tlbflush.h>
38 * online_page_callback contains pointer to current page onlining function.
39 * Initially it is generic_online_page(). If it is required it could be
40 * changed by calling set_online_page_callback() for callback registration
41 * and restore_online_page_callback() for generic callback restore.
44 static void generic_online_page(struct page
*page
);
46 static online_page_callback_t online_page_callback
= generic_online_page
;
48 DEFINE_MUTEX(mem_hotplug_mutex
);
50 void lock_memory_hotplug(void)
52 mutex_lock(&mem_hotplug_mutex
);
54 /* for exclusive hibernation if CONFIG_HIBERNATION=y */
58 void unlock_memory_hotplug(void)
60 unlock_system_sleep();
61 mutex_unlock(&mem_hotplug_mutex
);
65 /* add this memory to iomem resource */
66 static struct resource
*register_memory_resource(u64 start
, u64 size
)
69 res
= kzalloc(sizeof(struct resource
), GFP_KERNEL
);
72 res
->name
= "System RAM";
74 res
->end
= start
+ size
- 1;
75 res
->flags
= IORESOURCE_MEM
| IORESOURCE_BUSY
;
76 if (request_resource(&iomem_resource
, res
) < 0) {
77 printk("System RAM resource %pR cannot be added\n", res
);
84 static void release_memory_resource(struct resource
*res
)
88 release_resource(res
);
93 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
94 #ifndef CONFIG_SPARSEMEM_VMEMMAP
95 static void get_page_bootmem(unsigned long info
, struct page
*page
,
98 page
->lru
.next
= (struct list_head
*) type
;
100 set_page_private(page
, info
);
101 atomic_inc(&page
->_count
);
104 /* reference to __meminit __free_pages_bootmem is valid
105 * so use __ref to tell modpost not to generate a warning */
106 void __ref
put_page_bootmem(struct page
*page
)
109 static DEFINE_MUTEX(ppb_lock
);
111 type
= (unsigned long) page
->lru
.next
;
112 BUG_ON(type
< MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE
||
113 type
> MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE
);
115 if (atomic_dec_return(&page
->_count
) == 1) {
116 ClearPagePrivate(page
);
117 set_page_private(page
, 0);
118 INIT_LIST_HEAD(&page
->lru
);
121 * Please refer to comment for __free_pages_bootmem()
122 * for why we serialize here.
124 mutex_lock(&ppb_lock
);
125 __free_pages_bootmem(page
, 0);
126 mutex_unlock(&ppb_lock
);
131 static void register_page_bootmem_info_section(unsigned long start_pfn
)
133 unsigned long *usemap
, mapsize
, section_nr
, i
;
134 struct mem_section
*ms
;
135 struct page
*page
, *memmap
;
137 section_nr
= pfn_to_section_nr(start_pfn
);
138 ms
= __nr_to_section(section_nr
);
140 /* Get section's memmap address */
141 memmap
= sparse_decode_mem_map(ms
->section_mem_map
, section_nr
);
144 * Get page for the memmap's phys address
145 * XXX: need more consideration for sparse_vmemmap...
147 page
= virt_to_page(memmap
);
148 mapsize
= sizeof(struct page
) * PAGES_PER_SECTION
;
149 mapsize
= PAGE_ALIGN(mapsize
) >> PAGE_SHIFT
;
151 /* remember memmap's page */
152 for (i
= 0; i
< mapsize
; i
++, page
++)
153 get_page_bootmem(section_nr
, page
, SECTION_INFO
);
155 usemap
= __nr_to_section(section_nr
)->pageblock_flags
;
156 page
= virt_to_page(usemap
);
158 mapsize
= PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT
;
160 for (i
= 0; i
< mapsize
; i
++, page
++)
161 get_page_bootmem(section_nr
, page
, MIX_SECTION_INFO
);
165 void register_page_bootmem_info_node(struct pglist_data
*pgdat
)
167 unsigned long i
, pfn
, end_pfn
, nr_pages
;
168 int node
= pgdat
->node_id
;
172 nr_pages
= PAGE_ALIGN(sizeof(struct pglist_data
)) >> PAGE_SHIFT
;
173 page
= virt_to_page(pgdat
);
175 for (i
= 0; i
< nr_pages
; i
++, page
++)
176 get_page_bootmem(node
, page
, NODE_INFO
);
178 zone
= &pgdat
->node_zones
[0];
179 for (; zone
< pgdat
->node_zones
+ MAX_NR_ZONES
- 1; zone
++) {
180 if (zone
->wait_table
) {
181 nr_pages
= zone
->wait_table_hash_nr_entries
182 * sizeof(wait_queue_head_t
);
183 nr_pages
= PAGE_ALIGN(nr_pages
) >> PAGE_SHIFT
;
184 page
= virt_to_page(zone
->wait_table
);
186 for (i
= 0; i
< nr_pages
; i
++, page
++)
187 get_page_bootmem(node
, page
, NODE_INFO
);
191 pfn
= pgdat
->node_start_pfn
;
192 end_pfn
= pfn
+ pgdat
->node_spanned_pages
;
194 /* register_section info */
195 for (; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
197 * Some platforms can assign the same pfn to multiple nodes - on
198 * node0 as well as nodeN. To avoid registering a pfn against
199 * multiple nodes we check that this pfn does not already
200 * reside in some other node.
202 if (pfn_valid(pfn
) && (pfn_to_nid(pfn
) == node
))
203 register_page_bootmem_info_section(pfn
);
206 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
208 static void grow_zone_span(struct zone
*zone
, unsigned long start_pfn
,
209 unsigned long end_pfn
)
211 unsigned long old_zone_end_pfn
;
213 zone_span_writelock(zone
);
215 old_zone_end_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
216 if (!zone
->spanned_pages
|| start_pfn
< zone
->zone_start_pfn
)
217 zone
->zone_start_pfn
= start_pfn
;
219 zone
->spanned_pages
= max(old_zone_end_pfn
, end_pfn
) -
220 zone
->zone_start_pfn
;
222 zone_span_writeunlock(zone
);
225 static void resize_zone(struct zone
*zone
, unsigned long start_pfn
,
226 unsigned long end_pfn
)
228 zone_span_writelock(zone
);
230 if (end_pfn
- start_pfn
) {
231 zone
->zone_start_pfn
= start_pfn
;
232 zone
->spanned_pages
= end_pfn
- start_pfn
;
235 * make it consist as free_area_init_core(),
236 * if spanned_pages = 0, then keep start_pfn = 0
238 zone
->zone_start_pfn
= 0;
239 zone
->spanned_pages
= 0;
242 zone_span_writeunlock(zone
);
245 static void fix_zone_id(struct zone
*zone
, unsigned long start_pfn
,
246 unsigned long end_pfn
)
248 enum zone_type zid
= zone_idx(zone
);
249 int nid
= zone
->zone_pgdat
->node_id
;
252 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
253 set_page_links(pfn_to_page(pfn
), zid
, nid
, pfn
);
256 static int __meminit
move_pfn_range_left(struct zone
*z1
, struct zone
*z2
,
257 unsigned long start_pfn
, unsigned long end_pfn
)
261 unsigned long z1_start_pfn
;
263 if (!z1
->wait_table
) {
264 ret
= init_currently_empty_zone(z1
, start_pfn
,
265 end_pfn
- start_pfn
, MEMMAP_HOTPLUG
);
270 pgdat_resize_lock(z1
->zone_pgdat
, &flags
);
272 /* can't move pfns which are higher than @z2 */
273 if (end_pfn
> z2
->zone_start_pfn
+ z2
->spanned_pages
)
275 /* the move out part mast at the left most of @z2 */
276 if (start_pfn
> z2
->zone_start_pfn
)
278 /* must included/overlap */
279 if (end_pfn
<= z2
->zone_start_pfn
)
282 /* use start_pfn for z1's start_pfn if z1 is empty */
283 if (z1
->spanned_pages
)
284 z1_start_pfn
= z1
->zone_start_pfn
;
286 z1_start_pfn
= start_pfn
;
288 resize_zone(z1
, z1_start_pfn
, end_pfn
);
289 resize_zone(z2
, end_pfn
, z2
->zone_start_pfn
+ z2
->spanned_pages
);
291 pgdat_resize_unlock(z1
->zone_pgdat
, &flags
);
293 fix_zone_id(z1
, start_pfn
, end_pfn
);
297 pgdat_resize_unlock(z1
->zone_pgdat
, &flags
);
301 static int __meminit
move_pfn_range_right(struct zone
*z1
, struct zone
*z2
,
302 unsigned long start_pfn
, unsigned long end_pfn
)
306 unsigned long z2_end_pfn
;
308 if (!z2
->wait_table
) {
309 ret
= init_currently_empty_zone(z2
, start_pfn
,
310 end_pfn
- start_pfn
, MEMMAP_HOTPLUG
);
315 pgdat_resize_lock(z1
->zone_pgdat
, &flags
);
317 /* can't move pfns which are lower than @z1 */
318 if (z1
->zone_start_pfn
> start_pfn
)
320 /* the move out part mast at the right most of @z1 */
321 if (z1
->zone_start_pfn
+ z1
->spanned_pages
> end_pfn
)
323 /* must included/overlap */
324 if (start_pfn
>= z1
->zone_start_pfn
+ z1
->spanned_pages
)
327 /* use end_pfn for z2's end_pfn if z2 is empty */
328 if (z2
->spanned_pages
)
329 z2_end_pfn
= z2
->zone_start_pfn
+ z2
->spanned_pages
;
331 z2_end_pfn
= end_pfn
;
333 resize_zone(z1
, z1
->zone_start_pfn
, start_pfn
);
334 resize_zone(z2
, start_pfn
, z2_end_pfn
);
336 pgdat_resize_unlock(z1
->zone_pgdat
, &flags
);
338 fix_zone_id(z2
, start_pfn
, end_pfn
);
342 pgdat_resize_unlock(z1
->zone_pgdat
, &flags
);
346 static void grow_pgdat_span(struct pglist_data
*pgdat
, unsigned long start_pfn
,
347 unsigned long end_pfn
)
349 unsigned long old_pgdat_end_pfn
=
350 pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
352 if (!pgdat
->node_spanned_pages
|| start_pfn
< pgdat
->node_start_pfn
)
353 pgdat
->node_start_pfn
= start_pfn
;
355 pgdat
->node_spanned_pages
= max(old_pgdat_end_pfn
, end_pfn
) -
356 pgdat
->node_start_pfn
;
359 static int __meminit
__add_zone(struct zone
*zone
, unsigned long phys_start_pfn
)
361 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
362 int nr_pages
= PAGES_PER_SECTION
;
363 int nid
= pgdat
->node_id
;
367 zone_type
= zone
- pgdat
->node_zones
;
368 if (!zone
->wait_table
) {
371 ret
= init_currently_empty_zone(zone
, phys_start_pfn
,
372 nr_pages
, MEMMAP_HOTPLUG
);
376 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
377 grow_zone_span(zone
, phys_start_pfn
, phys_start_pfn
+ nr_pages
);
378 grow_pgdat_span(zone
->zone_pgdat
, phys_start_pfn
,
379 phys_start_pfn
+ nr_pages
);
380 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
381 memmap_init_zone(nr_pages
, nid
, zone_type
,
382 phys_start_pfn
, MEMMAP_HOTPLUG
);
386 static int __meminit
__add_section(int nid
, struct zone
*zone
,
387 unsigned long phys_start_pfn
)
389 int nr_pages
= PAGES_PER_SECTION
;
392 if (pfn_valid(phys_start_pfn
))
395 ret
= sparse_add_one_section(zone
, phys_start_pfn
, nr_pages
);
400 ret
= __add_zone(zone
, phys_start_pfn
);
405 return register_new_memory(nid
, __pfn_to_section(phys_start_pfn
));
408 #ifdef CONFIG_SPARSEMEM_VMEMMAP
409 static int __remove_section(struct zone
*zone
, struct mem_section
*ms
)
412 * XXX: Freeing memmap with vmemmap is not implement yet.
413 * This should be removed later.
418 static int __remove_section(struct zone
*zone
, struct mem_section
*ms
)
421 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
424 if (!valid_section(ms
))
427 ret
= unregister_memory_section(ms
);
431 pgdat_resize_lock(pgdat
, &flags
);
432 sparse_remove_one_section(zone
, ms
);
433 pgdat_resize_unlock(pgdat
, &flags
);
439 * Reasonably generic function for adding memory. It is
440 * expected that archs that support memory hotplug will
441 * call this function after deciding the zone to which to
444 int __ref
__add_pages(int nid
, struct zone
*zone
, unsigned long phys_start_pfn
,
445 unsigned long nr_pages
)
449 int start_sec
, end_sec
;
450 /* during initialize mem_map, align hot-added range to section */
451 start_sec
= pfn_to_section_nr(phys_start_pfn
);
452 end_sec
= pfn_to_section_nr(phys_start_pfn
+ nr_pages
- 1);
454 for (i
= start_sec
; i
<= end_sec
; i
++) {
455 err
= __add_section(nid
, zone
, i
<< PFN_SECTION_SHIFT
);
458 * EEXIST is finally dealt with by ioresource collision
459 * check. see add_memory() => register_memory_resource()
460 * Warning will be printed if there is collision.
462 if (err
&& (err
!= -EEXIST
))
469 EXPORT_SYMBOL_GPL(__add_pages
);
472 * __remove_pages() - remove sections of pages from a zone
473 * @zone: zone from which pages need to be removed
474 * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
475 * @nr_pages: number of pages to remove (must be multiple of section size)
477 * Generic helper function to remove section mappings and sysfs entries
478 * for the section of the memory we are removing. Caller needs to make
479 * sure that pages are marked reserved and zones are adjust properly by
480 * calling offline_pages().
482 int __remove_pages(struct zone
*zone
, unsigned long phys_start_pfn
,
483 unsigned long nr_pages
)
485 unsigned long i
, ret
= 0;
486 int sections_to_remove
;
489 * We can only remove entire sections
491 BUG_ON(phys_start_pfn
& ~PAGE_SECTION_MASK
);
492 BUG_ON(nr_pages
% PAGES_PER_SECTION
);
494 release_mem_region(phys_start_pfn
<< PAGE_SHIFT
, nr_pages
* PAGE_SIZE
);
496 sections_to_remove
= nr_pages
/ PAGES_PER_SECTION
;
497 for (i
= 0; i
< sections_to_remove
; i
++) {
498 unsigned long pfn
= phys_start_pfn
+ i
*PAGES_PER_SECTION
;
499 ret
= __remove_section(zone
, __pfn_to_section(pfn
));
505 EXPORT_SYMBOL_GPL(__remove_pages
);
507 int set_online_page_callback(online_page_callback_t callback
)
511 lock_memory_hotplug();
513 if (online_page_callback
== generic_online_page
) {
514 online_page_callback
= callback
;
518 unlock_memory_hotplug();
522 EXPORT_SYMBOL_GPL(set_online_page_callback
);
524 int restore_online_page_callback(online_page_callback_t callback
)
528 lock_memory_hotplug();
530 if (online_page_callback
== callback
) {
531 online_page_callback
= generic_online_page
;
535 unlock_memory_hotplug();
539 EXPORT_SYMBOL_GPL(restore_online_page_callback
);
541 void __online_page_set_limits(struct page
*page
)
543 unsigned long pfn
= page_to_pfn(page
);
545 if (pfn
>= num_physpages
)
546 num_physpages
= pfn
+ 1;
548 EXPORT_SYMBOL_GPL(__online_page_set_limits
);
550 void __online_page_increment_counters(struct page
*page
)
554 #ifdef CONFIG_HIGHMEM
555 if (PageHighMem(page
))
559 EXPORT_SYMBOL_GPL(__online_page_increment_counters
);
561 void __online_page_free(struct page
*page
)
563 ClearPageReserved(page
);
564 init_page_count(page
);
567 EXPORT_SYMBOL_GPL(__online_page_free
);
569 static void generic_online_page(struct page
*page
)
571 __online_page_set_limits(page
);
572 __online_page_increment_counters(page
);
573 __online_page_free(page
);
576 static int online_pages_range(unsigned long start_pfn
, unsigned long nr_pages
,
580 unsigned long onlined_pages
= *(unsigned long *)arg
;
582 if (PageReserved(pfn_to_page(start_pfn
)))
583 for (i
= 0; i
< nr_pages
; i
++) {
584 page
= pfn_to_page(start_pfn
+ i
);
585 (*online_page_callback
)(page
);
588 *(unsigned long *)arg
= onlined_pages
;
592 #ifdef CONFIG_MOVABLE_NODE
594 * When CONFIG_MOVABLE_NODE, we permit onlining of a node which doesn't have
597 static bool can_online_high_movable(struct zone
*zone
)
601 #else /* CONFIG_MOVABLE_NODE */
602 /* ensure every online node has NORMAL memory */
603 static bool can_online_high_movable(struct zone
*zone
)
605 return node_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
607 #endif /* CONFIG_MOVABLE_NODE */
609 /* check which state of node_states will be changed when online memory */
610 static void node_states_check_changes_online(unsigned long nr_pages
,
611 struct zone
*zone
, struct memory_notify
*arg
)
613 int nid
= zone_to_nid(zone
);
614 enum zone_type zone_last
= ZONE_NORMAL
;
617 * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
618 * contains nodes which have zones of 0...ZONE_NORMAL,
619 * set zone_last to ZONE_NORMAL.
621 * If we don't have HIGHMEM nor movable node,
622 * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
623 * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
625 if (N_MEMORY
== N_NORMAL_MEMORY
)
626 zone_last
= ZONE_MOVABLE
;
629 * if the memory to be online is in a zone of 0...zone_last, and
630 * the zones of 0...zone_last don't have memory before online, we will
631 * need to set the node to node_states[N_NORMAL_MEMORY] after
632 * the memory is online.
634 if (zone_idx(zone
) <= zone_last
&& !node_state(nid
, N_NORMAL_MEMORY
))
635 arg
->status_change_nid_normal
= nid
;
637 arg
->status_change_nid_normal
= -1;
639 #ifdef CONFIG_HIGHMEM
641 * If we have movable node, node_states[N_HIGH_MEMORY]
642 * contains nodes which have zones of 0...ZONE_HIGHMEM,
643 * set zone_last to ZONE_HIGHMEM.
645 * If we don't have movable node, node_states[N_NORMAL_MEMORY]
646 * contains nodes which have zones of 0...ZONE_MOVABLE,
647 * set zone_last to ZONE_MOVABLE.
649 zone_last
= ZONE_HIGHMEM
;
650 if (N_MEMORY
== N_HIGH_MEMORY
)
651 zone_last
= ZONE_MOVABLE
;
653 if (zone_idx(zone
) <= zone_last
&& !node_state(nid
, N_HIGH_MEMORY
))
654 arg
->status_change_nid_high
= nid
;
656 arg
->status_change_nid_high
= -1;
658 arg
->status_change_nid_high
= arg
->status_change_nid_normal
;
662 * if the node don't have memory befor online, we will need to
663 * set the node to node_states[N_MEMORY] after the memory
666 if (!node_state(nid
, N_MEMORY
))
667 arg
->status_change_nid
= nid
;
669 arg
->status_change_nid
= -1;
672 static void node_states_set_node(int node
, struct memory_notify
*arg
)
674 if (arg
->status_change_nid_normal
>= 0)
675 node_set_state(node
, N_NORMAL_MEMORY
);
677 if (arg
->status_change_nid_high
>= 0)
678 node_set_state(node
, N_HIGH_MEMORY
);
680 node_set_state(node
, N_MEMORY
);
684 int __ref
online_pages(unsigned long pfn
, unsigned long nr_pages
, int online_type
)
686 unsigned long onlined_pages
= 0;
688 int need_zonelists_rebuild
= 0;
691 struct memory_notify arg
;
693 lock_memory_hotplug();
695 * This doesn't need a lock to do pfn_to_page().
696 * The section can't be removed here because of the
697 * memory_block->state_mutex.
699 zone
= page_zone(pfn_to_page(pfn
));
701 if ((zone_idx(zone
) > ZONE_NORMAL
|| online_type
== ONLINE_MOVABLE
) &&
702 !can_online_high_movable(zone
)) {
703 unlock_memory_hotplug();
707 if (online_type
== ONLINE_KERNEL
&& zone_idx(zone
) == ZONE_MOVABLE
) {
708 if (move_pfn_range_left(zone
- 1, zone
, pfn
, pfn
+ nr_pages
)) {
709 unlock_memory_hotplug();
713 if (online_type
== ONLINE_MOVABLE
&& zone_idx(zone
) == ZONE_MOVABLE
- 1) {
714 if (move_pfn_range_right(zone
, zone
+ 1, pfn
, pfn
+ nr_pages
)) {
715 unlock_memory_hotplug();
720 /* Previous code may changed the zone of the pfn range */
721 zone
= page_zone(pfn_to_page(pfn
));
724 arg
.nr_pages
= nr_pages
;
725 node_states_check_changes_online(nr_pages
, zone
, &arg
);
727 nid
= page_to_nid(pfn_to_page(pfn
));
729 ret
= memory_notify(MEM_GOING_ONLINE
, &arg
);
730 ret
= notifier_to_errno(ret
);
732 memory_notify(MEM_CANCEL_ONLINE
, &arg
);
733 unlock_memory_hotplug();
737 * If this zone is not populated, then it is not in zonelist.
738 * This means the page allocator ignores this zone.
739 * So, zonelist must be updated after online.
741 mutex_lock(&zonelists_mutex
);
742 if (!populated_zone(zone
)) {
743 need_zonelists_rebuild
= 1;
744 build_all_zonelists(NULL
, zone
);
747 ret
= walk_system_ram_range(pfn
, nr_pages
, &onlined_pages
,
750 if (need_zonelists_rebuild
)
751 zone_pcp_reset(zone
);
752 mutex_unlock(&zonelists_mutex
);
753 printk(KERN_DEBUG
"online_pages [mem %#010llx-%#010llx] failed\n",
754 (unsigned long long) pfn
<< PAGE_SHIFT
,
755 (((unsigned long long) pfn
+ nr_pages
)
757 memory_notify(MEM_CANCEL_ONLINE
, &arg
);
758 unlock_memory_hotplug();
762 zone
->managed_pages
+= onlined_pages
;
763 zone
->present_pages
+= onlined_pages
;
764 zone
->zone_pgdat
->node_present_pages
+= onlined_pages
;
766 node_states_set_node(zone_to_nid(zone
), &arg
);
767 if (need_zonelists_rebuild
)
768 build_all_zonelists(NULL
, NULL
);
770 zone_pcp_update(zone
);
773 mutex_unlock(&zonelists_mutex
);
775 init_per_zone_wmark_min();
778 kswapd_run(zone_to_nid(zone
));
780 vm_total_pages
= nr_free_pagecache_pages();
782 writeback_set_ratelimit();
785 memory_notify(MEM_ONLINE
, &arg
);
786 unlock_memory_hotplug();
790 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
792 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
793 static pg_data_t __ref
*hotadd_new_pgdat(int nid
, u64 start
)
795 struct pglist_data
*pgdat
;
796 unsigned long zones_size
[MAX_NR_ZONES
] = {0};
797 unsigned long zholes_size
[MAX_NR_ZONES
] = {0};
798 unsigned long start_pfn
= start
>> PAGE_SHIFT
;
800 pgdat
= arch_alloc_nodedata(nid
);
804 arch_refresh_nodedata(nid
, pgdat
);
806 /* we can use NODE_DATA(nid) from here */
808 /* init node's zones as empty zones, we don't have any present pages.*/
809 free_area_init_node(nid
, zones_size
, start_pfn
, zholes_size
);
812 * The node we allocated has no zone fallback lists. For avoiding
813 * to access not-initialized zonelist, build here.
815 mutex_lock(&zonelists_mutex
);
816 build_all_zonelists(pgdat
, NULL
);
817 mutex_unlock(&zonelists_mutex
);
822 static void rollback_node_hotadd(int nid
, pg_data_t
*pgdat
)
824 arch_refresh_nodedata(nid
, NULL
);
825 arch_free_nodedata(pgdat
);
831 * called by cpu_up() to online a node without onlined memory.
833 int mem_online_node(int nid
)
838 lock_memory_hotplug();
839 pgdat
= hotadd_new_pgdat(nid
, 0);
844 node_set_online(nid
);
845 ret
= register_one_node(nid
);
849 unlock_memory_hotplug();
853 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
854 int __ref
add_memory(int nid
, u64 start
, u64 size
)
856 pg_data_t
*pgdat
= NULL
;
858 struct resource
*res
;
861 lock_memory_hotplug();
863 res
= register_memory_resource(start
, size
);
868 if (!node_online(nid
)) {
869 pgdat
= hotadd_new_pgdat(nid
, start
);
876 /* call arch's memory hotadd */
877 ret
= arch_add_memory(nid
, start
, size
);
882 /* we online node here. we can't roll back from here. */
883 node_set_online(nid
);
886 ret
= register_one_node(nid
);
888 * If sysfs file of new node can't create, cpu on the node
889 * can't be hot-added. There is no rollback way now.
890 * So, check by BUG_ON() to catch it reluctantly..
895 /* create new memmap entry */
896 firmware_map_add_hotplug(start
, start
+ size
, "System RAM");
901 /* rollback pgdat allocation and others */
903 rollback_node_hotadd(nid
, pgdat
);
905 release_memory_resource(res
);
908 unlock_memory_hotplug();
911 EXPORT_SYMBOL_GPL(add_memory
);
913 #ifdef CONFIG_MEMORY_HOTREMOVE
915 * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
916 * set and the size of the free page is given by page_order(). Using this,
917 * the function determines if the pageblock contains only free pages.
918 * Due to buddy contraints, a free page at least the size of a pageblock will
919 * be located at the start of the pageblock
921 static inline int pageblock_free(struct page
*page
)
923 return PageBuddy(page
) && page_order(page
) >= pageblock_order
;
926 /* Return the start of the next active pageblock after a given page */
927 static struct page
*next_active_pageblock(struct page
*page
)
929 /* Ensure the starting page is pageblock-aligned */
930 BUG_ON(page_to_pfn(page
) & (pageblock_nr_pages
- 1));
932 /* If the entire pageblock is free, move to the end of free page */
933 if (pageblock_free(page
)) {
935 /* be careful. we don't have locks, page_order can be changed.*/
936 order
= page_order(page
);
937 if ((order
< MAX_ORDER
) && (order
>= pageblock_order
))
938 return page
+ (1 << order
);
941 return page
+ pageblock_nr_pages
;
944 /* Checks if this range of memory is likely to be hot-removable. */
945 int is_mem_section_removable(unsigned long start_pfn
, unsigned long nr_pages
)
947 struct page
*page
= pfn_to_page(start_pfn
);
948 struct page
*end_page
= page
+ nr_pages
;
950 /* Check the starting page of each pageblock within the range */
951 for (; page
< end_page
; page
= next_active_pageblock(page
)) {
952 if (!is_pageblock_removable_nolock(page
))
957 /* All pageblocks in the memory block are likely to be hot-removable */
962 * Confirm all pages in a range [start, end) is belongs to the same zone.
964 static int test_pages_in_a_zone(unsigned long start_pfn
, unsigned long end_pfn
)
967 struct zone
*zone
= NULL
;
970 for (pfn
= start_pfn
;
972 pfn
+= MAX_ORDER_NR_PAGES
) {
974 /* This is just a CONFIG_HOLES_IN_ZONE check.*/
975 while ((i
< MAX_ORDER_NR_PAGES
) && !pfn_valid_within(pfn
+ i
))
977 if (i
== MAX_ORDER_NR_PAGES
)
979 page
= pfn_to_page(pfn
+ i
);
980 if (zone
&& page_zone(page
) != zone
)
982 zone
= page_zone(page
);
988 * Scanning pfn is much easier than scanning lru list.
989 * Scan pfn from start to end and Find LRU page.
991 static unsigned long scan_lru_pages(unsigned long start
, unsigned long end
)
995 for (pfn
= start
; pfn
< end
; pfn
++) {
996 if (pfn_valid(pfn
)) {
997 page
= pfn_to_page(pfn
);
1005 #define NR_OFFLINE_AT_ONCE_PAGES (256)
1007 do_migrate_range(unsigned long start_pfn
, unsigned long end_pfn
)
1011 int move_pages
= NR_OFFLINE_AT_ONCE_PAGES
;
1012 int not_managed
= 0;
1016 for (pfn
= start_pfn
; pfn
< end_pfn
&& move_pages
> 0; pfn
++) {
1017 if (!pfn_valid(pfn
))
1019 page
= pfn_to_page(pfn
);
1020 if (!get_page_unless_zero(page
))
1023 * We can skip free pages. And we can only deal with pages on
1026 ret
= isolate_lru_page(page
);
1027 if (!ret
) { /* Success */
1029 list_add_tail(&page
->lru
, &source
);
1031 inc_zone_page_state(page
, NR_ISOLATED_ANON
+
1032 page_is_file_cache(page
));
1035 #ifdef CONFIG_DEBUG_VM
1036 printk(KERN_ALERT
"removing pfn %lx from LRU failed\n",
1041 /* Because we don't have big zone->lock. we should
1042 check this again here. */
1043 if (page_count(page
)) {
1050 if (!list_empty(&source
)) {
1052 putback_lru_pages(&source
);
1057 * alloc_migrate_target should be improooooved!!
1058 * migrate_pages returns # of failed pages.
1060 ret
= migrate_pages(&source
, alloc_migrate_target
, 0,
1064 putback_lru_pages(&source
);
1071 * remove from free_area[] and mark all as Reserved.
1074 offline_isolated_pages_cb(unsigned long start
, unsigned long nr_pages
,
1077 __offline_isolated_pages(start
, start
+ nr_pages
);
1082 offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
1084 walk_system_ram_range(start_pfn
, end_pfn
- start_pfn
, NULL
,
1085 offline_isolated_pages_cb
);
1089 * Check all pages in range, recoreded as memory resource, are isolated.
1092 check_pages_isolated_cb(unsigned long start_pfn
, unsigned long nr_pages
,
1096 long offlined
= *(long *)data
;
1097 ret
= test_pages_isolated(start_pfn
, start_pfn
+ nr_pages
, true);
1098 offlined
= nr_pages
;
1100 *(long *)data
+= offlined
;
1105 check_pages_isolated(unsigned long start_pfn
, unsigned long end_pfn
)
1110 ret
= walk_system_ram_range(start_pfn
, end_pfn
- start_pfn
, &offlined
,
1111 check_pages_isolated_cb
);
1113 offlined
= (long)ret
;
1117 #ifdef CONFIG_MOVABLE_NODE
1119 * When CONFIG_MOVABLE_NODE, we permit offlining of a node which doesn't have
1122 static bool can_offline_normal(struct zone
*zone
, unsigned long nr_pages
)
1126 #else /* CONFIG_MOVABLE_NODE */
1127 /* ensure the node has NORMAL memory if it is still online */
1128 static bool can_offline_normal(struct zone
*zone
, unsigned long nr_pages
)
1130 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
1131 unsigned long present_pages
= 0;
1134 for (zt
= 0; zt
<= ZONE_NORMAL
; zt
++)
1135 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1137 if (present_pages
> nr_pages
)
1141 for (; zt
<= ZONE_MOVABLE
; zt
++)
1142 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1145 * we can't offline the last normal memory until all
1146 * higher memory is offlined.
1148 return present_pages
== 0;
1150 #endif /* CONFIG_MOVABLE_NODE */
1152 /* check which state of node_states will be changed when offline memory */
1153 static void node_states_check_changes_offline(unsigned long nr_pages
,
1154 struct zone
*zone
, struct memory_notify
*arg
)
1156 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
1157 unsigned long present_pages
= 0;
1158 enum zone_type zt
, zone_last
= ZONE_NORMAL
;
1161 * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
1162 * contains nodes which have zones of 0...ZONE_NORMAL,
1163 * set zone_last to ZONE_NORMAL.
1165 * If we don't have HIGHMEM nor movable node,
1166 * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
1167 * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
1169 if (N_MEMORY
== N_NORMAL_MEMORY
)
1170 zone_last
= ZONE_MOVABLE
;
1173 * check whether node_states[N_NORMAL_MEMORY] will be changed.
1174 * If the memory to be offline is in a zone of 0...zone_last,
1175 * and it is the last present memory, 0...zone_last will
1176 * become empty after offline , thus we can determind we will
1177 * need to clear the node from node_states[N_NORMAL_MEMORY].
1179 for (zt
= 0; zt
<= zone_last
; zt
++)
1180 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1181 if (zone_idx(zone
) <= zone_last
&& nr_pages
>= present_pages
)
1182 arg
->status_change_nid_normal
= zone_to_nid(zone
);
1184 arg
->status_change_nid_normal
= -1;
1186 #ifdef CONFIG_HIGHMEM
1188 * If we have movable node, node_states[N_HIGH_MEMORY]
1189 * contains nodes which have zones of 0...ZONE_HIGHMEM,
1190 * set zone_last to ZONE_HIGHMEM.
1192 * If we don't have movable node, node_states[N_NORMAL_MEMORY]
1193 * contains nodes which have zones of 0...ZONE_MOVABLE,
1194 * set zone_last to ZONE_MOVABLE.
1196 zone_last
= ZONE_HIGHMEM
;
1197 if (N_MEMORY
== N_HIGH_MEMORY
)
1198 zone_last
= ZONE_MOVABLE
;
1200 for (; zt
<= zone_last
; zt
++)
1201 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1202 if (zone_idx(zone
) <= zone_last
&& nr_pages
>= present_pages
)
1203 arg
->status_change_nid_high
= zone_to_nid(zone
);
1205 arg
->status_change_nid_high
= -1;
1207 arg
->status_change_nid_high
= arg
->status_change_nid_normal
;
1211 * node_states[N_HIGH_MEMORY] contains nodes which have 0...ZONE_MOVABLE
1213 zone_last
= ZONE_MOVABLE
;
1216 * check whether node_states[N_HIGH_MEMORY] will be changed
1217 * If we try to offline the last present @nr_pages from the node,
1218 * we can determind we will need to clear the node from
1219 * node_states[N_HIGH_MEMORY].
1221 for (; zt
<= zone_last
; zt
++)
1222 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1223 if (nr_pages
>= present_pages
)
1224 arg
->status_change_nid
= zone_to_nid(zone
);
1226 arg
->status_change_nid
= -1;
1229 static void node_states_clear_node(int node
, struct memory_notify
*arg
)
1231 if (arg
->status_change_nid_normal
>= 0)
1232 node_clear_state(node
, N_NORMAL_MEMORY
);
1234 if ((N_MEMORY
!= N_NORMAL_MEMORY
) &&
1235 (arg
->status_change_nid_high
>= 0))
1236 node_clear_state(node
, N_HIGH_MEMORY
);
1238 if ((N_MEMORY
!= N_HIGH_MEMORY
) &&
1239 (arg
->status_change_nid
>= 0))
1240 node_clear_state(node
, N_MEMORY
);
1243 static int __ref
__offline_pages(unsigned long start_pfn
,
1244 unsigned long end_pfn
, unsigned long timeout
)
1246 unsigned long pfn
, nr_pages
, expire
;
1247 long offlined_pages
;
1248 int ret
, drain
, retry_max
, node
;
1250 struct memory_notify arg
;
1252 BUG_ON(start_pfn
>= end_pfn
);
1253 /* at least, alignment against pageblock is necessary */
1254 if (!IS_ALIGNED(start_pfn
, pageblock_nr_pages
))
1256 if (!IS_ALIGNED(end_pfn
, pageblock_nr_pages
))
1258 /* This makes hotplug much easier...and readable.
1259 we assume this for now. .*/
1260 if (!test_pages_in_a_zone(start_pfn
, end_pfn
))
1263 lock_memory_hotplug();
1265 zone
= page_zone(pfn_to_page(start_pfn
));
1266 node
= zone_to_nid(zone
);
1267 nr_pages
= end_pfn
- start_pfn
;
1270 if (zone_idx(zone
) <= ZONE_NORMAL
&& !can_offline_normal(zone
, nr_pages
))
1273 /* set above range as isolated */
1274 ret
= start_isolate_page_range(start_pfn
, end_pfn
,
1275 MIGRATE_MOVABLE
, true);
1279 arg
.start_pfn
= start_pfn
;
1280 arg
.nr_pages
= nr_pages
;
1281 node_states_check_changes_offline(nr_pages
, zone
, &arg
);
1283 ret
= memory_notify(MEM_GOING_OFFLINE
, &arg
);
1284 ret
= notifier_to_errno(ret
);
1286 goto failed_removal
;
1289 expire
= jiffies
+ timeout
;
1293 /* start memory hot removal */
1295 if (time_after(jiffies
, expire
))
1296 goto failed_removal
;
1298 if (signal_pending(current
))
1299 goto failed_removal
;
1302 lru_add_drain_all();
1307 pfn
= scan_lru_pages(start_pfn
, end_pfn
);
1308 if (pfn
) { /* We have page on LRU */
1309 ret
= do_migrate_range(pfn
, end_pfn
);
1315 if (--retry_max
== 0)
1316 goto failed_removal
;
1322 /* drain all zone's lru pagevec, this is asynchronous... */
1323 lru_add_drain_all();
1325 /* drain pcp pages, this is synchronous. */
1328 offlined_pages
= check_pages_isolated(start_pfn
, end_pfn
);
1329 if (offlined_pages
< 0) {
1331 goto failed_removal
;
1333 printk(KERN_INFO
"Offlined Pages %ld\n", offlined_pages
);
1334 /* Ok, all of our target is isolated.
1335 We cannot do rollback at this point. */
1336 offline_isolated_pages(start_pfn
, end_pfn
);
1337 /* reset pagetype flags and makes migrate type to be MOVABLE */
1338 undo_isolate_page_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
);
1339 /* removal success */
1340 zone
->managed_pages
-= offlined_pages
;
1341 zone
->present_pages
-= offlined_pages
;
1342 zone
->zone_pgdat
->node_present_pages
-= offlined_pages
;
1343 totalram_pages
-= offlined_pages
;
1345 init_per_zone_wmark_min();
1347 if (!populated_zone(zone
)) {
1348 zone_pcp_reset(zone
);
1349 mutex_lock(&zonelists_mutex
);
1350 build_all_zonelists(NULL
, NULL
);
1351 mutex_unlock(&zonelists_mutex
);
1353 zone_pcp_update(zone
);
1355 node_states_clear_node(node
, &arg
);
1356 if (arg
.status_change_nid
>= 0)
1359 vm_total_pages
= nr_free_pagecache_pages();
1360 writeback_set_ratelimit();
1362 memory_notify(MEM_OFFLINE
, &arg
);
1363 unlock_memory_hotplug();
1367 printk(KERN_INFO
"memory offlining [mem %#010llx-%#010llx] failed\n",
1368 (unsigned long long) start_pfn
<< PAGE_SHIFT
,
1369 ((unsigned long long) end_pfn
<< PAGE_SHIFT
) - 1);
1370 memory_notify(MEM_CANCEL_OFFLINE
, &arg
);
1371 /* pushback to free area */
1372 undo_isolate_page_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
);
1375 unlock_memory_hotplug();
1379 int offline_pages(unsigned long start_pfn
, unsigned long nr_pages
)
1381 return __offline_pages(start_pfn
, start_pfn
+ nr_pages
, 120 * HZ
);
1384 int remove_memory(u64 start
, u64 size
)
1386 struct memory_block
*mem
= NULL
;
1387 struct mem_section
*section
;
1388 unsigned long start_pfn
, end_pfn
;
1389 unsigned long pfn
, section_nr
;
1392 start_pfn
= PFN_DOWN(start
);
1393 end_pfn
= start_pfn
+ PFN_DOWN(size
);
1395 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
1396 section_nr
= pfn_to_section_nr(pfn
);
1397 if (!present_section_nr(section_nr
))
1400 section
= __nr_to_section(section_nr
);
1401 /* same memblock? */
1403 if ((section_nr
>= mem
->start_section_nr
) &&
1404 (section_nr
<= mem
->end_section_nr
))
1407 mem
= find_memory_block_hinted(section
, mem
);
1411 ret
= offline_memory_block(mem
);
1413 kobject_put(&mem
->dev
.kobj
);
1419 kobject_put(&mem
->dev
.kobj
);
1424 int offline_pages(unsigned long start_pfn
, unsigned long nr_pages
)
1428 int remove_memory(u64 start
, u64 size
)
1432 #endif /* CONFIG_MEMORY_HOTREMOVE */
1433 EXPORT_SYMBOL_GPL(remove_memory
);