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>
32 #include <linux/stop_machine.h>
34 #include <asm/tlbflush.h>
39 * online_page_callback contains pointer to current page onlining function.
40 * Initially it is generic_online_page(). If it is required it could be
41 * changed by calling set_online_page_callback() for callback registration
42 * and restore_online_page_callback() for generic callback restore.
45 static void generic_online_page(struct page
*page
);
47 static online_page_callback_t online_page_callback
= generic_online_page
;
49 DEFINE_MUTEX(mem_hotplug_mutex
);
51 void lock_memory_hotplug(void)
53 mutex_lock(&mem_hotplug_mutex
);
55 /* for exclusive hibernation if CONFIG_HIBERNATION=y */
59 void unlock_memory_hotplug(void)
61 unlock_system_sleep();
62 mutex_unlock(&mem_hotplug_mutex
);
66 /* add this memory to iomem resource */
67 static struct resource
*register_memory_resource(u64 start
, u64 size
)
70 res
= kzalloc(sizeof(struct resource
), GFP_KERNEL
);
73 res
->name
= "System RAM";
75 res
->end
= start
+ size
- 1;
76 res
->flags
= IORESOURCE_MEM
| IORESOURCE_BUSY
;
77 if (request_resource(&iomem_resource
, res
) < 0) {
78 printk("System RAM resource %pR cannot be added\n", res
);
85 static void release_memory_resource(struct resource
*res
)
89 release_resource(res
);
94 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
95 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
);
132 #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
133 #ifndef CONFIG_SPARSEMEM_VMEMMAP
134 static void register_page_bootmem_info_section(unsigned long start_pfn
)
136 unsigned long *usemap
, mapsize
, section_nr
, i
;
137 struct mem_section
*ms
;
138 struct page
*page
, *memmap
;
140 section_nr
= pfn_to_section_nr(start_pfn
);
141 ms
= __nr_to_section(section_nr
);
143 /* Get section's memmap address */
144 memmap
= sparse_decode_mem_map(ms
->section_mem_map
, section_nr
);
147 * Get page for the memmap's phys address
148 * XXX: need more consideration for sparse_vmemmap...
150 page
= virt_to_page(memmap
);
151 mapsize
= sizeof(struct page
) * PAGES_PER_SECTION
;
152 mapsize
= PAGE_ALIGN(mapsize
) >> PAGE_SHIFT
;
154 /* remember memmap's page */
155 for (i
= 0; i
< mapsize
; i
++, page
++)
156 get_page_bootmem(section_nr
, page
, SECTION_INFO
);
158 usemap
= __nr_to_section(section_nr
)->pageblock_flags
;
159 page
= virt_to_page(usemap
);
161 mapsize
= PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT
;
163 for (i
= 0; i
< mapsize
; i
++, page
++)
164 get_page_bootmem(section_nr
, page
, MIX_SECTION_INFO
);
167 #else /* CONFIG_SPARSEMEM_VMEMMAP */
168 static void register_page_bootmem_info_section(unsigned long start_pfn
)
170 unsigned long *usemap
, mapsize
, section_nr
, i
;
171 struct mem_section
*ms
;
172 struct page
*page
, *memmap
;
174 if (!pfn_valid(start_pfn
))
177 section_nr
= pfn_to_section_nr(start_pfn
);
178 ms
= __nr_to_section(section_nr
);
180 memmap
= sparse_decode_mem_map(ms
->section_mem_map
, section_nr
);
182 register_page_bootmem_memmap(section_nr
, memmap
, PAGES_PER_SECTION
);
184 usemap
= __nr_to_section(section_nr
)->pageblock_flags
;
185 page
= virt_to_page(usemap
);
187 mapsize
= PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT
;
189 for (i
= 0; i
< mapsize
; i
++, page
++)
190 get_page_bootmem(section_nr
, page
, MIX_SECTION_INFO
);
192 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
194 void register_page_bootmem_info_node(struct pglist_data
*pgdat
)
196 unsigned long i
, pfn
, end_pfn
, nr_pages
;
197 int node
= pgdat
->node_id
;
201 nr_pages
= PAGE_ALIGN(sizeof(struct pglist_data
)) >> PAGE_SHIFT
;
202 page
= virt_to_page(pgdat
);
204 for (i
= 0; i
< nr_pages
; i
++, page
++)
205 get_page_bootmem(node
, page
, NODE_INFO
);
207 zone
= &pgdat
->node_zones
[0];
208 for (; zone
< pgdat
->node_zones
+ MAX_NR_ZONES
- 1; zone
++) {
209 if (zone
->wait_table
) {
210 nr_pages
= zone
->wait_table_hash_nr_entries
211 * sizeof(wait_queue_head_t
);
212 nr_pages
= PAGE_ALIGN(nr_pages
) >> PAGE_SHIFT
;
213 page
= virt_to_page(zone
->wait_table
);
215 for (i
= 0; i
< nr_pages
; i
++, page
++)
216 get_page_bootmem(node
, page
, NODE_INFO
);
220 pfn
= pgdat
->node_start_pfn
;
221 end_pfn
= pgdat_end_pfn(pgdat
);
223 /* register_section info */
224 for (; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
226 * Some platforms can assign the same pfn to multiple nodes - on
227 * node0 as well as nodeN. To avoid registering a pfn against
228 * multiple nodes we check that this pfn does not already
229 * reside in some other node.
231 if (pfn_valid(pfn
) && (pfn_to_nid(pfn
) == node
))
232 register_page_bootmem_info_section(pfn
);
235 #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */
237 static void grow_zone_span(struct zone
*zone
, unsigned long start_pfn
,
238 unsigned long end_pfn
)
240 unsigned long old_zone_end_pfn
;
242 zone_span_writelock(zone
);
244 old_zone_end_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
245 if (!zone
->spanned_pages
|| start_pfn
< zone
->zone_start_pfn
)
246 zone
->zone_start_pfn
= start_pfn
;
248 zone
->spanned_pages
= max(old_zone_end_pfn
, end_pfn
) -
249 zone
->zone_start_pfn
;
251 zone_span_writeunlock(zone
);
254 static void resize_zone(struct zone
*zone
, unsigned long start_pfn
,
255 unsigned long end_pfn
)
257 zone_span_writelock(zone
);
259 if (end_pfn
- start_pfn
) {
260 zone
->zone_start_pfn
= start_pfn
;
261 zone
->spanned_pages
= end_pfn
- start_pfn
;
264 * make it consist as free_area_init_core(),
265 * if spanned_pages = 0, then keep start_pfn = 0
267 zone
->zone_start_pfn
= 0;
268 zone
->spanned_pages
= 0;
271 zone_span_writeunlock(zone
);
274 static void fix_zone_id(struct zone
*zone
, unsigned long start_pfn
,
275 unsigned long end_pfn
)
277 enum zone_type zid
= zone_idx(zone
);
278 int nid
= zone
->zone_pgdat
->node_id
;
281 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
282 set_page_links(pfn_to_page(pfn
), zid
, nid
, pfn
);
285 /* Can fail with -ENOMEM from allocating a wait table with vmalloc() or
286 * alloc_bootmem_node_nopanic() */
287 static int __ref
ensure_zone_is_initialized(struct zone
*zone
,
288 unsigned long start_pfn
, unsigned long num_pages
)
290 if (!zone_is_initialized(zone
))
291 return init_currently_empty_zone(zone
, start_pfn
, num_pages
,
296 static int __meminit
move_pfn_range_left(struct zone
*z1
, struct zone
*z2
,
297 unsigned long start_pfn
, unsigned long end_pfn
)
301 unsigned long z1_start_pfn
;
303 ret
= ensure_zone_is_initialized(z1
, start_pfn
, end_pfn
- start_pfn
);
307 pgdat_resize_lock(z1
->zone_pgdat
, &flags
);
309 /* can't move pfns which are higher than @z2 */
310 if (end_pfn
> zone_end_pfn(z2
))
312 /* the move out part mast at the left most of @z2 */
313 if (start_pfn
> z2
->zone_start_pfn
)
315 /* must included/overlap */
316 if (end_pfn
<= z2
->zone_start_pfn
)
319 /* use start_pfn for z1's start_pfn if z1 is empty */
320 if (z1
->spanned_pages
)
321 z1_start_pfn
= z1
->zone_start_pfn
;
323 z1_start_pfn
= start_pfn
;
325 resize_zone(z1
, z1_start_pfn
, end_pfn
);
326 resize_zone(z2
, end_pfn
, zone_end_pfn(z2
));
328 pgdat_resize_unlock(z1
->zone_pgdat
, &flags
);
330 fix_zone_id(z1
, start_pfn
, end_pfn
);
334 pgdat_resize_unlock(z1
->zone_pgdat
, &flags
);
338 static int __meminit
move_pfn_range_right(struct zone
*z1
, struct zone
*z2
,
339 unsigned long start_pfn
, unsigned long end_pfn
)
343 unsigned long z2_end_pfn
;
345 ret
= ensure_zone_is_initialized(z2
, start_pfn
, end_pfn
- start_pfn
);
349 pgdat_resize_lock(z1
->zone_pgdat
, &flags
);
351 /* can't move pfns which are lower than @z1 */
352 if (z1
->zone_start_pfn
> start_pfn
)
354 /* the move out part mast at the right most of @z1 */
355 if (zone_end_pfn(z1
) > end_pfn
)
357 /* must included/overlap */
358 if (start_pfn
>= zone_end_pfn(z1
))
361 /* use end_pfn for z2's end_pfn if z2 is empty */
362 if (z2
->spanned_pages
)
363 z2_end_pfn
= zone_end_pfn(z2
);
365 z2_end_pfn
= end_pfn
;
367 resize_zone(z1
, z1
->zone_start_pfn
, start_pfn
);
368 resize_zone(z2
, start_pfn
, z2_end_pfn
);
370 pgdat_resize_unlock(z1
->zone_pgdat
, &flags
);
372 fix_zone_id(z2
, start_pfn
, end_pfn
);
376 pgdat_resize_unlock(z1
->zone_pgdat
, &flags
);
380 static void grow_pgdat_span(struct pglist_data
*pgdat
, unsigned long start_pfn
,
381 unsigned long end_pfn
)
383 unsigned long old_pgdat_end_pfn
=
384 pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
386 if (!pgdat
->node_spanned_pages
|| start_pfn
< pgdat
->node_start_pfn
)
387 pgdat
->node_start_pfn
= start_pfn
;
389 pgdat
->node_spanned_pages
= max(old_pgdat_end_pfn
, end_pfn
) -
390 pgdat
->node_start_pfn
;
393 static int __meminit
__add_zone(struct zone
*zone
, unsigned long phys_start_pfn
)
395 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
396 int nr_pages
= PAGES_PER_SECTION
;
397 int nid
= pgdat
->node_id
;
402 zone_type
= zone
- pgdat
->node_zones
;
403 ret
= ensure_zone_is_initialized(zone
, phys_start_pfn
, nr_pages
);
407 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
408 grow_zone_span(zone
, phys_start_pfn
, phys_start_pfn
+ nr_pages
);
409 grow_pgdat_span(zone
->zone_pgdat
, phys_start_pfn
,
410 phys_start_pfn
+ nr_pages
);
411 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
412 memmap_init_zone(nr_pages
, nid
, zone_type
,
413 phys_start_pfn
, MEMMAP_HOTPLUG
);
417 static int __meminit
__add_section(int nid
, struct zone
*zone
,
418 unsigned long phys_start_pfn
)
420 int nr_pages
= PAGES_PER_SECTION
;
423 if (pfn_valid(phys_start_pfn
))
426 ret
= sparse_add_one_section(zone
, phys_start_pfn
, nr_pages
);
431 ret
= __add_zone(zone
, phys_start_pfn
);
436 return register_new_memory(nid
, __pfn_to_section(phys_start_pfn
));
439 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */
440 static int find_smallest_section_pfn(int nid
, struct zone
*zone
,
441 unsigned long start_pfn
,
442 unsigned long end_pfn
)
444 struct mem_section
*ms
;
446 for (; start_pfn
< end_pfn
; start_pfn
+= PAGES_PER_SECTION
) {
447 ms
= __pfn_to_section(start_pfn
);
449 if (unlikely(!valid_section(ms
)))
452 if (unlikely(pfn_to_nid(start_pfn
) != nid
))
455 if (zone
&& zone
!= page_zone(pfn_to_page(start_pfn
)))
464 /* find the biggest valid pfn in the range [start_pfn, end_pfn). */
465 static int find_biggest_section_pfn(int nid
, struct zone
*zone
,
466 unsigned long start_pfn
,
467 unsigned long end_pfn
)
469 struct mem_section
*ms
;
472 /* pfn is the end pfn of a memory section. */
474 for (; pfn
>= start_pfn
; pfn
-= PAGES_PER_SECTION
) {
475 ms
= __pfn_to_section(pfn
);
477 if (unlikely(!valid_section(ms
)))
480 if (unlikely(pfn_to_nid(pfn
) != nid
))
483 if (zone
&& zone
!= page_zone(pfn_to_page(pfn
)))
492 static void shrink_zone_span(struct zone
*zone
, unsigned long start_pfn
,
493 unsigned long end_pfn
)
495 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
496 unsigned long zone_end_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
498 struct mem_section
*ms
;
499 int nid
= zone_to_nid(zone
);
501 zone_span_writelock(zone
);
502 if (zone_start_pfn
== start_pfn
) {
504 * If the section is smallest section in the zone, it need
505 * shrink zone->zone_start_pfn and zone->zone_spanned_pages.
506 * In this case, we find second smallest valid mem_section
507 * for shrinking zone.
509 pfn
= find_smallest_section_pfn(nid
, zone
, end_pfn
,
512 zone
->zone_start_pfn
= pfn
;
513 zone
->spanned_pages
= zone_end_pfn
- pfn
;
515 } else if (zone_end_pfn
== end_pfn
) {
517 * If the section is biggest section in the zone, it need
518 * shrink zone->spanned_pages.
519 * In this case, we find second biggest valid mem_section for
522 pfn
= find_biggest_section_pfn(nid
, zone
, zone_start_pfn
,
525 zone
->spanned_pages
= pfn
- zone_start_pfn
+ 1;
529 * The section is not biggest or smallest mem_section in the zone, it
530 * only creates a hole in the zone. So in this case, we need not
531 * change the zone. But perhaps, the zone has only hole data. Thus
532 * it check the zone has only hole or not.
534 pfn
= zone_start_pfn
;
535 for (; pfn
< zone_end_pfn
; pfn
+= PAGES_PER_SECTION
) {
536 ms
= __pfn_to_section(pfn
);
538 if (unlikely(!valid_section(ms
)))
541 if (page_zone(pfn_to_page(pfn
)) != zone
)
544 /* If the section is current section, it continues the loop */
545 if (start_pfn
== pfn
)
548 /* If we find valid section, we have nothing to do */
549 zone_span_writeunlock(zone
);
553 /* The zone has no valid section */
554 zone
->zone_start_pfn
= 0;
555 zone
->spanned_pages
= 0;
556 zone_span_writeunlock(zone
);
559 static void shrink_pgdat_span(struct pglist_data
*pgdat
,
560 unsigned long start_pfn
, unsigned long end_pfn
)
562 unsigned long pgdat_start_pfn
= pgdat
->node_start_pfn
;
563 unsigned long pgdat_end_pfn
=
564 pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
566 struct mem_section
*ms
;
567 int nid
= pgdat
->node_id
;
569 if (pgdat_start_pfn
== start_pfn
) {
571 * If the section is smallest section in the pgdat, it need
572 * shrink pgdat->node_start_pfn and pgdat->node_spanned_pages.
573 * In this case, we find second smallest valid mem_section
574 * for shrinking zone.
576 pfn
= find_smallest_section_pfn(nid
, NULL
, end_pfn
,
579 pgdat
->node_start_pfn
= pfn
;
580 pgdat
->node_spanned_pages
= pgdat_end_pfn
- pfn
;
582 } else if (pgdat_end_pfn
== end_pfn
) {
584 * If the section is biggest section in the pgdat, it need
585 * shrink pgdat->node_spanned_pages.
586 * In this case, we find second biggest valid mem_section for
589 pfn
= find_biggest_section_pfn(nid
, NULL
, pgdat_start_pfn
,
592 pgdat
->node_spanned_pages
= pfn
- pgdat_start_pfn
+ 1;
596 * If the section is not biggest or smallest mem_section in the pgdat,
597 * it only creates a hole in the pgdat. So in this case, we need not
599 * But perhaps, the pgdat has only hole data. Thus it check the pgdat
600 * has only hole or not.
602 pfn
= pgdat_start_pfn
;
603 for (; pfn
< pgdat_end_pfn
; pfn
+= PAGES_PER_SECTION
) {
604 ms
= __pfn_to_section(pfn
);
606 if (unlikely(!valid_section(ms
)))
609 if (pfn_to_nid(pfn
) != nid
)
612 /* If the section is current section, it continues the loop */
613 if (start_pfn
== pfn
)
616 /* If we find valid section, we have nothing to do */
620 /* The pgdat has no valid section */
621 pgdat
->node_start_pfn
= 0;
622 pgdat
->node_spanned_pages
= 0;
625 static void __remove_zone(struct zone
*zone
, unsigned long start_pfn
)
627 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
628 int nr_pages
= PAGES_PER_SECTION
;
632 zone_type
= zone
- pgdat
->node_zones
;
634 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
635 shrink_zone_span(zone
, start_pfn
, start_pfn
+ nr_pages
);
636 shrink_pgdat_span(pgdat
, start_pfn
, start_pfn
+ nr_pages
);
637 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
640 static int __remove_section(struct zone
*zone
, struct mem_section
*ms
)
642 unsigned long start_pfn
;
646 if (!valid_section(ms
))
649 ret
= unregister_memory_section(ms
);
653 scn_nr
= __section_nr(ms
);
654 start_pfn
= section_nr_to_pfn(scn_nr
);
655 __remove_zone(zone
, start_pfn
);
657 sparse_remove_one_section(zone
, ms
);
662 * Reasonably generic function for adding memory. It is
663 * expected that archs that support memory hotplug will
664 * call this function after deciding the zone to which to
667 int __ref
__add_pages(int nid
, struct zone
*zone
, unsigned long phys_start_pfn
,
668 unsigned long nr_pages
)
672 int start_sec
, end_sec
;
673 /* during initialize mem_map, align hot-added range to section */
674 start_sec
= pfn_to_section_nr(phys_start_pfn
);
675 end_sec
= pfn_to_section_nr(phys_start_pfn
+ nr_pages
- 1);
677 for (i
= start_sec
; i
<= end_sec
; i
++) {
678 err
= __add_section(nid
, zone
, i
<< PFN_SECTION_SHIFT
);
681 * EEXIST is finally dealt with by ioresource collision
682 * check. see add_memory() => register_memory_resource()
683 * Warning will be printed if there is collision.
685 if (err
&& (err
!= -EEXIST
))
692 EXPORT_SYMBOL_GPL(__add_pages
);
695 * __remove_pages() - remove sections of pages from a zone
696 * @zone: zone from which pages need to be removed
697 * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
698 * @nr_pages: number of pages to remove (must be multiple of section size)
700 * Generic helper function to remove section mappings and sysfs entries
701 * for the section of the memory we are removing. Caller needs to make
702 * sure that pages are marked reserved and zones are adjust properly by
703 * calling offline_pages().
705 int __remove_pages(struct zone
*zone
, unsigned long phys_start_pfn
,
706 unsigned long nr_pages
)
709 int sections_to_remove
;
710 resource_size_t start
, size
;
714 * We can only remove entire sections
716 BUG_ON(phys_start_pfn
& ~PAGE_SECTION_MASK
);
717 BUG_ON(nr_pages
% PAGES_PER_SECTION
);
719 start
= phys_start_pfn
<< PAGE_SHIFT
;
720 size
= nr_pages
* PAGE_SIZE
;
721 ret
= release_mem_region_adjustable(&iomem_resource
, start
, size
);
723 pr_warn("Unable to release resource <%016llx-%016llx> (%d)\n",
724 start
, start
+ size
- 1, ret
);
726 sections_to_remove
= nr_pages
/ PAGES_PER_SECTION
;
727 for (i
= 0; i
< sections_to_remove
; i
++) {
728 unsigned long pfn
= phys_start_pfn
+ i
*PAGES_PER_SECTION
;
729 ret
= __remove_section(zone
, __pfn_to_section(pfn
));
735 EXPORT_SYMBOL_GPL(__remove_pages
);
737 int set_online_page_callback(online_page_callback_t callback
)
741 lock_memory_hotplug();
743 if (online_page_callback
== generic_online_page
) {
744 online_page_callback
= callback
;
748 unlock_memory_hotplug();
752 EXPORT_SYMBOL_GPL(set_online_page_callback
);
754 int restore_online_page_callback(online_page_callback_t callback
)
758 lock_memory_hotplug();
760 if (online_page_callback
== callback
) {
761 online_page_callback
= generic_online_page
;
765 unlock_memory_hotplug();
769 EXPORT_SYMBOL_GPL(restore_online_page_callback
);
771 void __online_page_set_limits(struct page
*page
)
773 unsigned long pfn
= page_to_pfn(page
);
775 if (pfn
>= num_physpages
)
776 num_physpages
= pfn
+ 1;
778 EXPORT_SYMBOL_GPL(__online_page_set_limits
);
780 void __online_page_increment_counters(struct page
*page
)
784 #ifdef CONFIG_HIGHMEM
785 if (PageHighMem(page
))
789 EXPORT_SYMBOL_GPL(__online_page_increment_counters
);
791 void __online_page_free(struct page
*page
)
793 ClearPageReserved(page
);
794 init_page_count(page
);
797 EXPORT_SYMBOL_GPL(__online_page_free
);
799 static void generic_online_page(struct page
*page
)
801 __online_page_set_limits(page
);
802 __online_page_increment_counters(page
);
803 __online_page_free(page
);
806 static int online_pages_range(unsigned long start_pfn
, unsigned long nr_pages
,
810 unsigned long onlined_pages
= *(unsigned long *)arg
;
812 if (PageReserved(pfn_to_page(start_pfn
)))
813 for (i
= 0; i
< nr_pages
; i
++) {
814 page
= pfn_to_page(start_pfn
+ i
);
815 (*online_page_callback
)(page
);
818 *(unsigned long *)arg
= onlined_pages
;
822 #ifdef CONFIG_MOVABLE_NODE
824 * When CONFIG_MOVABLE_NODE, we permit onlining of a node which doesn't have
827 static bool can_online_high_movable(struct zone
*zone
)
831 #else /* CONFIG_MOVABLE_NODE */
832 /* ensure every online node has NORMAL memory */
833 static bool can_online_high_movable(struct zone
*zone
)
835 return node_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
837 #endif /* CONFIG_MOVABLE_NODE */
839 /* check which state of node_states will be changed when online memory */
840 static void node_states_check_changes_online(unsigned long nr_pages
,
841 struct zone
*zone
, struct memory_notify
*arg
)
843 int nid
= zone_to_nid(zone
);
844 enum zone_type zone_last
= ZONE_NORMAL
;
847 * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
848 * contains nodes which have zones of 0...ZONE_NORMAL,
849 * set zone_last to ZONE_NORMAL.
851 * If we don't have HIGHMEM nor movable node,
852 * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
853 * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
855 if (N_MEMORY
== N_NORMAL_MEMORY
)
856 zone_last
= ZONE_MOVABLE
;
859 * if the memory to be online is in a zone of 0...zone_last, and
860 * the zones of 0...zone_last don't have memory before online, we will
861 * need to set the node to node_states[N_NORMAL_MEMORY] after
862 * the memory is online.
864 if (zone_idx(zone
) <= zone_last
&& !node_state(nid
, N_NORMAL_MEMORY
))
865 arg
->status_change_nid_normal
= nid
;
867 arg
->status_change_nid_normal
= -1;
869 #ifdef CONFIG_HIGHMEM
871 * If we have movable node, node_states[N_HIGH_MEMORY]
872 * contains nodes which have zones of 0...ZONE_HIGHMEM,
873 * set zone_last to ZONE_HIGHMEM.
875 * If we don't have movable node, node_states[N_NORMAL_MEMORY]
876 * contains nodes which have zones of 0...ZONE_MOVABLE,
877 * set zone_last to ZONE_MOVABLE.
879 zone_last
= ZONE_HIGHMEM
;
880 if (N_MEMORY
== N_HIGH_MEMORY
)
881 zone_last
= ZONE_MOVABLE
;
883 if (zone_idx(zone
) <= zone_last
&& !node_state(nid
, N_HIGH_MEMORY
))
884 arg
->status_change_nid_high
= nid
;
886 arg
->status_change_nid_high
= -1;
888 arg
->status_change_nid_high
= arg
->status_change_nid_normal
;
892 * if the node don't have memory befor online, we will need to
893 * set the node to node_states[N_MEMORY] after the memory
896 if (!node_state(nid
, N_MEMORY
))
897 arg
->status_change_nid
= nid
;
899 arg
->status_change_nid
= -1;
902 static void node_states_set_node(int node
, struct memory_notify
*arg
)
904 if (arg
->status_change_nid_normal
>= 0)
905 node_set_state(node
, N_NORMAL_MEMORY
);
907 if (arg
->status_change_nid_high
>= 0)
908 node_set_state(node
, N_HIGH_MEMORY
);
910 node_set_state(node
, N_MEMORY
);
914 int __ref
online_pages(unsigned long pfn
, unsigned long nr_pages
, int online_type
)
916 unsigned long onlined_pages
= 0;
918 int need_zonelists_rebuild
= 0;
921 struct memory_notify arg
;
923 lock_memory_hotplug();
925 * This doesn't need a lock to do pfn_to_page().
926 * The section can't be removed here because of the
927 * memory_block->state_mutex.
929 zone
= page_zone(pfn_to_page(pfn
));
931 if ((zone_idx(zone
) > ZONE_NORMAL
|| online_type
== ONLINE_MOVABLE
) &&
932 !can_online_high_movable(zone
)) {
933 unlock_memory_hotplug();
937 if (online_type
== ONLINE_KERNEL
&& zone_idx(zone
) == ZONE_MOVABLE
) {
938 if (move_pfn_range_left(zone
- 1, zone
, pfn
, pfn
+ nr_pages
)) {
939 unlock_memory_hotplug();
943 if (online_type
== ONLINE_MOVABLE
&& zone_idx(zone
) == ZONE_MOVABLE
- 1) {
944 if (move_pfn_range_right(zone
, zone
+ 1, pfn
, pfn
+ nr_pages
)) {
945 unlock_memory_hotplug();
950 /* Previous code may changed the zone of the pfn range */
951 zone
= page_zone(pfn_to_page(pfn
));
954 arg
.nr_pages
= nr_pages
;
955 node_states_check_changes_online(nr_pages
, zone
, &arg
);
957 nid
= page_to_nid(pfn_to_page(pfn
));
959 ret
= memory_notify(MEM_GOING_ONLINE
, &arg
);
960 ret
= notifier_to_errno(ret
);
962 memory_notify(MEM_CANCEL_ONLINE
, &arg
);
963 unlock_memory_hotplug();
967 * If this zone is not populated, then it is not in zonelist.
968 * This means the page allocator ignores this zone.
969 * So, zonelist must be updated after online.
971 mutex_lock(&zonelists_mutex
);
972 if (!populated_zone(zone
)) {
973 need_zonelists_rebuild
= 1;
974 build_all_zonelists(NULL
, zone
);
977 ret
= walk_system_ram_range(pfn
, nr_pages
, &onlined_pages
,
980 if (need_zonelists_rebuild
)
981 zone_pcp_reset(zone
);
982 mutex_unlock(&zonelists_mutex
);
983 printk(KERN_DEBUG
"online_pages [mem %#010llx-%#010llx] failed\n",
984 (unsigned long long) pfn
<< PAGE_SHIFT
,
985 (((unsigned long long) pfn
+ nr_pages
)
987 memory_notify(MEM_CANCEL_ONLINE
, &arg
);
988 unlock_memory_hotplug();
992 zone
->managed_pages
+= onlined_pages
;
993 zone
->present_pages
+= onlined_pages
;
994 zone
->zone_pgdat
->node_present_pages
+= onlined_pages
;
996 node_states_set_node(zone_to_nid(zone
), &arg
);
997 if (need_zonelists_rebuild
)
998 build_all_zonelists(NULL
, NULL
);
1000 zone_pcp_update(zone
);
1003 mutex_unlock(&zonelists_mutex
);
1005 init_per_zone_wmark_min();
1008 kswapd_run(zone_to_nid(zone
));
1010 vm_total_pages
= nr_free_pagecache_pages();
1012 writeback_set_ratelimit();
1015 memory_notify(MEM_ONLINE
, &arg
);
1016 unlock_memory_hotplug();
1020 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
1022 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
1023 static pg_data_t __ref
*hotadd_new_pgdat(int nid
, u64 start
)
1025 struct pglist_data
*pgdat
;
1026 unsigned long zones_size
[MAX_NR_ZONES
] = {0};
1027 unsigned long zholes_size
[MAX_NR_ZONES
] = {0};
1028 unsigned long start_pfn
= start
>> PAGE_SHIFT
;
1030 pgdat
= NODE_DATA(nid
);
1032 pgdat
= arch_alloc_nodedata(nid
);
1036 arch_refresh_nodedata(nid
, pgdat
);
1039 /* we can use NODE_DATA(nid) from here */
1041 /* init node's zones as empty zones, we don't have any present pages.*/
1042 free_area_init_node(nid
, zones_size
, start_pfn
, zholes_size
);
1045 * The node we allocated has no zone fallback lists. For avoiding
1046 * to access not-initialized zonelist, build here.
1048 mutex_lock(&zonelists_mutex
);
1049 build_all_zonelists(pgdat
, NULL
);
1050 mutex_unlock(&zonelists_mutex
);
1055 static void rollback_node_hotadd(int nid
, pg_data_t
*pgdat
)
1057 arch_refresh_nodedata(nid
, NULL
);
1058 arch_free_nodedata(pgdat
);
1064 * called by cpu_up() to online a node without onlined memory.
1066 int mem_online_node(int nid
)
1071 lock_memory_hotplug();
1072 pgdat
= hotadd_new_pgdat(nid
, 0);
1077 node_set_online(nid
);
1078 ret
= register_one_node(nid
);
1082 unlock_memory_hotplug();
1086 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
1087 int __ref
add_memory(int nid
, u64 start
, u64 size
)
1089 pg_data_t
*pgdat
= NULL
;
1092 struct resource
*res
;
1095 lock_memory_hotplug();
1097 res
= register_memory_resource(start
, size
);
1102 { /* Stupid hack to suppress address-never-null warning */
1103 void *p
= NODE_DATA(nid
);
1106 new_node
= !node_online(nid
);
1108 pgdat
= hotadd_new_pgdat(nid
, start
);
1114 /* call arch's memory hotadd */
1115 ret
= arch_add_memory(nid
, start
, size
);
1120 /* we online node here. we can't roll back from here. */
1121 node_set_online(nid
);
1124 ret
= register_one_node(nid
);
1126 * If sysfs file of new node can't create, cpu on the node
1127 * can't be hot-added. There is no rollback way now.
1128 * So, check by BUG_ON() to catch it reluctantly..
1133 /* create new memmap entry */
1134 firmware_map_add_hotplug(start
, start
+ size
, "System RAM");
1139 /* rollback pgdat allocation and others */
1141 rollback_node_hotadd(nid
, pgdat
);
1142 release_memory_resource(res
);
1145 unlock_memory_hotplug();
1148 EXPORT_SYMBOL_GPL(add_memory
);
1150 #ifdef CONFIG_MEMORY_HOTREMOVE
1152 * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
1153 * set and the size of the free page is given by page_order(). Using this,
1154 * the function determines if the pageblock contains only free pages.
1155 * Due to buddy contraints, a free page at least the size of a pageblock will
1156 * be located at the start of the pageblock
1158 static inline int pageblock_free(struct page
*page
)
1160 return PageBuddy(page
) && page_order(page
) >= pageblock_order
;
1163 /* Return the start of the next active pageblock after a given page */
1164 static struct page
*next_active_pageblock(struct page
*page
)
1166 /* Ensure the starting page is pageblock-aligned */
1167 BUG_ON(page_to_pfn(page
) & (pageblock_nr_pages
- 1));
1169 /* If the entire pageblock is free, move to the end of free page */
1170 if (pageblock_free(page
)) {
1172 /* be careful. we don't have locks, page_order can be changed.*/
1173 order
= page_order(page
);
1174 if ((order
< MAX_ORDER
) && (order
>= pageblock_order
))
1175 return page
+ (1 << order
);
1178 return page
+ pageblock_nr_pages
;
1181 /* Checks if this range of memory is likely to be hot-removable. */
1182 int is_mem_section_removable(unsigned long start_pfn
, unsigned long nr_pages
)
1184 struct page
*page
= pfn_to_page(start_pfn
);
1185 struct page
*end_page
= page
+ nr_pages
;
1187 /* Check the starting page of each pageblock within the range */
1188 for (; page
< end_page
; page
= next_active_pageblock(page
)) {
1189 if (!is_pageblock_removable_nolock(page
))
1194 /* All pageblocks in the memory block are likely to be hot-removable */
1199 * Confirm all pages in a range [start, end) is belongs to the same zone.
1201 static int test_pages_in_a_zone(unsigned long start_pfn
, unsigned long end_pfn
)
1204 struct zone
*zone
= NULL
;
1207 for (pfn
= start_pfn
;
1209 pfn
+= MAX_ORDER_NR_PAGES
) {
1211 /* This is just a CONFIG_HOLES_IN_ZONE check.*/
1212 while ((i
< MAX_ORDER_NR_PAGES
) && !pfn_valid_within(pfn
+ i
))
1214 if (i
== MAX_ORDER_NR_PAGES
)
1216 page
= pfn_to_page(pfn
+ i
);
1217 if (zone
&& page_zone(page
) != zone
)
1219 zone
= page_zone(page
);
1225 * Scanning pfn is much easier than scanning lru list.
1226 * Scan pfn from start to end and Find LRU page.
1228 static unsigned long scan_lru_pages(unsigned long start
, unsigned long end
)
1232 for (pfn
= start
; pfn
< end
; pfn
++) {
1233 if (pfn_valid(pfn
)) {
1234 page
= pfn_to_page(pfn
);
1242 #define NR_OFFLINE_AT_ONCE_PAGES (256)
1244 do_migrate_range(unsigned long start_pfn
, unsigned long end_pfn
)
1248 int move_pages
= NR_OFFLINE_AT_ONCE_PAGES
;
1249 int not_managed
= 0;
1253 for (pfn
= start_pfn
; pfn
< end_pfn
&& move_pages
> 0; pfn
++) {
1254 if (!pfn_valid(pfn
))
1256 page
= pfn_to_page(pfn
);
1257 if (!get_page_unless_zero(page
))
1260 * We can skip free pages. And we can only deal with pages on
1263 ret
= isolate_lru_page(page
);
1264 if (!ret
) { /* Success */
1266 list_add_tail(&page
->lru
, &source
);
1268 inc_zone_page_state(page
, NR_ISOLATED_ANON
+
1269 page_is_file_cache(page
));
1272 #ifdef CONFIG_DEBUG_VM
1273 printk(KERN_ALERT
"removing pfn %lx from LRU failed\n",
1278 /* Because we don't have big zone->lock. we should
1279 check this again here. */
1280 if (page_count(page
)) {
1287 if (!list_empty(&source
)) {
1289 putback_lru_pages(&source
);
1294 * alloc_migrate_target should be improooooved!!
1295 * migrate_pages returns # of failed pages.
1297 ret
= migrate_pages(&source
, alloc_migrate_target
, 0,
1298 MIGRATE_SYNC
, MR_MEMORY_HOTPLUG
);
1300 putback_lru_pages(&source
);
1307 * remove from free_area[] and mark all as Reserved.
1310 offline_isolated_pages_cb(unsigned long start
, unsigned long nr_pages
,
1313 __offline_isolated_pages(start
, start
+ nr_pages
);
1318 offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
1320 walk_system_ram_range(start_pfn
, end_pfn
- start_pfn
, NULL
,
1321 offline_isolated_pages_cb
);
1325 * Check all pages in range, recoreded as memory resource, are isolated.
1328 check_pages_isolated_cb(unsigned long start_pfn
, unsigned long nr_pages
,
1332 long offlined
= *(long *)data
;
1333 ret
= test_pages_isolated(start_pfn
, start_pfn
+ nr_pages
, true);
1334 offlined
= nr_pages
;
1336 *(long *)data
+= offlined
;
1341 check_pages_isolated(unsigned long start_pfn
, unsigned long end_pfn
)
1346 ret
= walk_system_ram_range(start_pfn
, end_pfn
- start_pfn
, &offlined
,
1347 check_pages_isolated_cb
);
1349 offlined
= (long)ret
;
1353 #ifdef CONFIG_MOVABLE_NODE
1355 * When CONFIG_MOVABLE_NODE, we permit offlining of a node which doesn't have
1358 static bool can_offline_normal(struct zone
*zone
, unsigned long nr_pages
)
1362 #else /* CONFIG_MOVABLE_NODE */
1363 /* ensure the node has NORMAL memory if it is still online */
1364 static bool can_offline_normal(struct zone
*zone
, unsigned long nr_pages
)
1366 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
1367 unsigned long present_pages
= 0;
1370 for (zt
= 0; zt
<= ZONE_NORMAL
; zt
++)
1371 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1373 if (present_pages
> nr_pages
)
1377 for (; zt
<= ZONE_MOVABLE
; zt
++)
1378 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1381 * we can't offline the last normal memory until all
1382 * higher memory is offlined.
1384 return present_pages
== 0;
1386 #endif /* CONFIG_MOVABLE_NODE */
1388 /* check which state of node_states will be changed when offline memory */
1389 static void node_states_check_changes_offline(unsigned long nr_pages
,
1390 struct zone
*zone
, struct memory_notify
*arg
)
1392 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
1393 unsigned long present_pages
= 0;
1394 enum zone_type zt
, zone_last
= ZONE_NORMAL
;
1397 * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
1398 * contains nodes which have zones of 0...ZONE_NORMAL,
1399 * set zone_last to ZONE_NORMAL.
1401 * If we don't have HIGHMEM nor movable node,
1402 * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
1403 * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
1405 if (N_MEMORY
== N_NORMAL_MEMORY
)
1406 zone_last
= ZONE_MOVABLE
;
1409 * check whether node_states[N_NORMAL_MEMORY] will be changed.
1410 * If the memory to be offline is in a zone of 0...zone_last,
1411 * and it is the last present memory, 0...zone_last will
1412 * become empty after offline , thus we can determind we will
1413 * need to clear the node from node_states[N_NORMAL_MEMORY].
1415 for (zt
= 0; zt
<= zone_last
; zt
++)
1416 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1417 if (zone_idx(zone
) <= zone_last
&& nr_pages
>= present_pages
)
1418 arg
->status_change_nid_normal
= zone_to_nid(zone
);
1420 arg
->status_change_nid_normal
= -1;
1422 #ifdef CONFIG_HIGHMEM
1424 * If we have movable node, node_states[N_HIGH_MEMORY]
1425 * contains nodes which have zones of 0...ZONE_HIGHMEM,
1426 * set zone_last to ZONE_HIGHMEM.
1428 * If we don't have movable node, node_states[N_NORMAL_MEMORY]
1429 * contains nodes which have zones of 0...ZONE_MOVABLE,
1430 * set zone_last to ZONE_MOVABLE.
1432 zone_last
= ZONE_HIGHMEM
;
1433 if (N_MEMORY
== N_HIGH_MEMORY
)
1434 zone_last
= ZONE_MOVABLE
;
1436 for (; zt
<= zone_last
; zt
++)
1437 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1438 if (zone_idx(zone
) <= zone_last
&& nr_pages
>= present_pages
)
1439 arg
->status_change_nid_high
= zone_to_nid(zone
);
1441 arg
->status_change_nid_high
= -1;
1443 arg
->status_change_nid_high
= arg
->status_change_nid_normal
;
1447 * node_states[N_HIGH_MEMORY] contains nodes which have 0...ZONE_MOVABLE
1449 zone_last
= ZONE_MOVABLE
;
1452 * check whether node_states[N_HIGH_MEMORY] will be changed
1453 * If we try to offline the last present @nr_pages from the node,
1454 * we can determind we will need to clear the node from
1455 * node_states[N_HIGH_MEMORY].
1457 for (; zt
<= zone_last
; zt
++)
1458 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1459 if (nr_pages
>= present_pages
)
1460 arg
->status_change_nid
= zone_to_nid(zone
);
1462 arg
->status_change_nid
= -1;
1465 static void node_states_clear_node(int node
, struct memory_notify
*arg
)
1467 if (arg
->status_change_nid_normal
>= 0)
1468 node_clear_state(node
, N_NORMAL_MEMORY
);
1470 if ((N_MEMORY
!= N_NORMAL_MEMORY
) &&
1471 (arg
->status_change_nid_high
>= 0))
1472 node_clear_state(node
, N_HIGH_MEMORY
);
1474 if ((N_MEMORY
!= N_HIGH_MEMORY
) &&
1475 (arg
->status_change_nid
>= 0))
1476 node_clear_state(node
, N_MEMORY
);
1479 static int __ref
__offline_pages(unsigned long start_pfn
,
1480 unsigned long end_pfn
, unsigned long timeout
)
1482 unsigned long pfn
, nr_pages
, expire
;
1483 long offlined_pages
;
1484 int ret
, drain
, retry_max
, node
;
1486 struct memory_notify arg
;
1488 BUG_ON(start_pfn
>= end_pfn
);
1489 /* at least, alignment against pageblock is necessary */
1490 if (!IS_ALIGNED(start_pfn
, pageblock_nr_pages
))
1492 if (!IS_ALIGNED(end_pfn
, pageblock_nr_pages
))
1494 /* This makes hotplug much easier...and readable.
1495 we assume this for now. .*/
1496 if (!test_pages_in_a_zone(start_pfn
, end_pfn
))
1499 lock_memory_hotplug();
1501 zone
= page_zone(pfn_to_page(start_pfn
));
1502 node
= zone_to_nid(zone
);
1503 nr_pages
= end_pfn
- start_pfn
;
1506 if (zone_idx(zone
) <= ZONE_NORMAL
&& !can_offline_normal(zone
, nr_pages
))
1509 /* set above range as isolated */
1510 ret
= start_isolate_page_range(start_pfn
, end_pfn
,
1511 MIGRATE_MOVABLE
, true);
1515 arg
.start_pfn
= start_pfn
;
1516 arg
.nr_pages
= nr_pages
;
1517 node_states_check_changes_offline(nr_pages
, zone
, &arg
);
1519 ret
= memory_notify(MEM_GOING_OFFLINE
, &arg
);
1520 ret
= notifier_to_errno(ret
);
1522 goto failed_removal
;
1525 expire
= jiffies
+ timeout
;
1529 /* start memory hot removal */
1531 if (time_after(jiffies
, expire
))
1532 goto failed_removal
;
1534 if (signal_pending(current
))
1535 goto failed_removal
;
1538 lru_add_drain_all();
1543 pfn
= scan_lru_pages(start_pfn
, end_pfn
);
1544 if (pfn
) { /* We have page on LRU */
1545 ret
= do_migrate_range(pfn
, end_pfn
);
1551 if (--retry_max
== 0)
1552 goto failed_removal
;
1558 /* drain all zone's lru pagevec, this is asynchronous... */
1559 lru_add_drain_all();
1561 /* drain pcp pages, this is synchronous. */
1564 offlined_pages
= check_pages_isolated(start_pfn
, end_pfn
);
1565 if (offlined_pages
< 0) {
1567 goto failed_removal
;
1569 printk(KERN_INFO
"Offlined Pages %ld\n", offlined_pages
);
1570 /* Ok, all of our target is isolated.
1571 We cannot do rollback at this point. */
1572 offline_isolated_pages(start_pfn
, end_pfn
);
1573 /* reset pagetype flags and makes migrate type to be MOVABLE */
1574 undo_isolate_page_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
);
1575 /* removal success */
1576 zone
->managed_pages
-= offlined_pages
;
1577 zone
->present_pages
-= offlined_pages
;
1578 zone
->zone_pgdat
->node_present_pages
-= offlined_pages
;
1579 totalram_pages
-= offlined_pages
;
1581 init_per_zone_wmark_min();
1583 if (!populated_zone(zone
)) {
1584 zone_pcp_reset(zone
);
1585 mutex_lock(&zonelists_mutex
);
1586 build_all_zonelists(NULL
, NULL
);
1587 mutex_unlock(&zonelists_mutex
);
1589 zone_pcp_update(zone
);
1591 node_states_clear_node(node
, &arg
);
1592 if (arg
.status_change_nid
>= 0)
1595 vm_total_pages
= nr_free_pagecache_pages();
1596 writeback_set_ratelimit();
1598 memory_notify(MEM_OFFLINE
, &arg
);
1599 unlock_memory_hotplug();
1603 printk(KERN_INFO
"memory offlining [mem %#010llx-%#010llx] failed\n",
1604 (unsigned long long) start_pfn
<< PAGE_SHIFT
,
1605 ((unsigned long long) end_pfn
<< PAGE_SHIFT
) - 1);
1606 memory_notify(MEM_CANCEL_OFFLINE
, &arg
);
1607 /* pushback to free area */
1608 undo_isolate_page_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
);
1611 unlock_memory_hotplug();
1615 int offline_pages(unsigned long start_pfn
, unsigned long nr_pages
)
1617 return __offline_pages(start_pfn
, start_pfn
+ nr_pages
, 120 * HZ
);
1621 * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn)
1622 * @start_pfn: start pfn of the memory range
1623 * @end_pfn: end pfn of the memory range
1624 * @arg: argument passed to func
1625 * @func: callback for each memory section walked
1627 * This function walks through all present mem sections in range
1628 * [start_pfn, end_pfn) and call func on each mem section.
1630 * Returns the return value of func.
1632 static int walk_memory_range(unsigned long start_pfn
, unsigned long end_pfn
,
1633 void *arg
, int (*func
)(struct memory_block
*, void *))
1635 struct memory_block
*mem
= NULL
;
1636 struct mem_section
*section
;
1637 unsigned long pfn
, section_nr
;
1640 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
1641 section_nr
= pfn_to_section_nr(pfn
);
1642 if (!present_section_nr(section_nr
))
1645 section
= __nr_to_section(section_nr
);
1646 /* same memblock? */
1648 if ((section_nr
>= mem
->start_section_nr
) &&
1649 (section_nr
<= mem
->end_section_nr
))
1652 mem
= find_memory_block_hinted(section
, mem
);
1656 ret
= func(mem
, arg
);
1658 kobject_put(&mem
->dev
.kobj
);
1664 kobject_put(&mem
->dev
.kobj
);
1670 * offline_memory_block_cb - callback function for offlining memory block
1671 * @mem: the memory block to be offlined
1672 * @arg: buffer to hold error msg
1674 * Always return 0, and put the error msg in arg if any.
1676 static int offline_memory_block_cb(struct memory_block
*mem
, void *arg
)
1679 int error
= offline_memory_block(mem
);
1681 if (error
!= 0 && *ret
== 0)
1687 static int is_memblock_offlined_cb(struct memory_block
*mem
, void *arg
)
1689 int ret
= !is_memblock_offlined(mem
);
1692 pr_warn("removing memory fails, because memory "
1693 "[%#010llx-%#010llx] is onlined\n",
1694 PFN_PHYS(section_nr_to_pfn(mem
->start_section_nr
)),
1695 PFN_PHYS(section_nr_to_pfn(mem
->end_section_nr
+ 1))-1);
1700 static int check_cpu_on_node(void *data
)
1702 struct pglist_data
*pgdat
= data
;
1705 for_each_present_cpu(cpu
) {
1706 if (cpu_to_node(cpu
) == pgdat
->node_id
)
1708 * the cpu on this node isn't removed, and we can't
1709 * offline this node.
1717 static void unmap_cpu_on_node(void *data
)
1719 #ifdef CONFIG_ACPI_NUMA
1720 struct pglist_data
*pgdat
= data
;
1723 for_each_possible_cpu(cpu
)
1724 if (cpu_to_node(cpu
) == pgdat
->node_id
)
1725 numa_clear_node(cpu
);
1729 static int check_and_unmap_cpu_on_node(void *data
)
1731 int ret
= check_cpu_on_node(data
);
1737 * the node will be offlined when we come here, so we can clear
1738 * the cpu_to_node() now.
1741 unmap_cpu_on_node(data
);
1745 /* offline the node if all memory sections of this node are removed */
1746 void try_offline_node(int nid
)
1748 pg_data_t
*pgdat
= NODE_DATA(nid
);
1749 unsigned long start_pfn
= pgdat
->node_start_pfn
;
1750 unsigned long end_pfn
= start_pfn
+ pgdat
->node_spanned_pages
;
1752 struct page
*pgdat_page
= virt_to_page(pgdat
);
1755 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
1756 unsigned long section_nr
= pfn_to_section_nr(pfn
);
1758 if (!present_section_nr(section_nr
))
1761 if (pfn_to_nid(pfn
) != nid
)
1765 * some memory sections of this node are not removed, and we
1766 * can't offline node now.
1771 if (stop_machine(check_and_unmap_cpu_on_node
, pgdat
, NULL
))
1775 * all memory/cpu of this node are removed, we can offline this
1778 node_set_offline(nid
);
1779 unregister_one_node(nid
);
1781 if (!PageSlab(pgdat_page
) && !PageCompound(pgdat_page
))
1782 /* node data is allocated from boot memory */
1785 /* free waittable in each zone */
1786 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
1787 struct zone
*zone
= pgdat
->node_zones
+ i
;
1790 * wait_table may be allocated from boot memory,
1791 * here only free if it's allocated by vmalloc.
1793 if (is_vmalloc_addr(zone
->wait_table
))
1794 vfree(zone
->wait_table
);
1798 * Since there is no way to guarentee the address of pgdat/zone is not
1799 * on stack of any kernel threads or used by other kernel objects
1800 * without reference counting or other symchronizing method, do not
1801 * reset node_data and free pgdat here. Just reset it to 0 and reuse
1802 * the memory when the node is online again.
1804 memset(pgdat
, 0, sizeof(*pgdat
));
1806 EXPORT_SYMBOL(try_offline_node
);
1808 int __ref
remove_memory(int nid
, u64 start
, u64 size
)
1810 unsigned long start_pfn
, end_pfn
;
1814 start_pfn
= PFN_DOWN(start
);
1815 end_pfn
= PFN_UP(start
+ size
- 1);
1818 * When CONFIG_MEMCG is on, one memory block may be used by other
1819 * blocks to store page cgroup when onlining pages. But we don't know
1820 * in what order pages are onlined. So we iterate twice to offline
1822 * 1st iterate: offline every non primary memory block.
1823 * 2nd iterate: offline primary (i.e. first added) memory block.
1826 walk_memory_range(start_pfn
, end_pfn
, &ret
,
1827 offline_memory_block_cb
);
1837 lock_memory_hotplug();
1840 * we have offlined all memory blocks like this:
1841 * 1. lock memory hotplug
1842 * 2. offline a memory block
1843 * 3. unlock memory hotplug
1845 * repeat step1-3 to offline the memory block. All memory blocks
1846 * must be offlined before removing memory. But we don't hold the
1847 * lock in the whole operation. So we should check whether all
1848 * memory blocks are offlined.
1851 ret
= walk_memory_range(start_pfn
, end_pfn
, NULL
,
1852 is_memblock_offlined_cb
);
1854 unlock_memory_hotplug();
1858 /* remove memmap entry */
1859 firmware_map_remove(start
, start
+ size
, "System RAM");
1861 arch_remove_memory(start
, size
);
1863 try_offline_node(nid
);
1865 unlock_memory_hotplug();
1870 int offline_pages(unsigned long start_pfn
, unsigned long nr_pages
)
1874 int remove_memory(int nid
, u64 start
, u64 size
)
1878 #endif /* CONFIG_MEMORY_HOTREMOVE */
1879 EXPORT_SYMBOL_GPL(remove_memory
);