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>
33 #include <linux/hugetlb.h>
34 #include <linux/memblock.h>
36 #include <asm/tlbflush.h>
41 * online_page_callback contains pointer to current page onlining function.
42 * Initially it is generic_online_page(). If it is required it could be
43 * changed by calling set_online_page_callback() for callback registration
44 * and restore_online_page_callback() for generic callback restore.
47 static void generic_online_page(struct page
*page
);
49 static online_page_callback_t online_page_callback
= generic_online_page
;
51 DEFINE_MUTEX(mem_hotplug_mutex
);
53 void lock_memory_hotplug(void)
55 mutex_lock(&mem_hotplug_mutex
);
58 void unlock_memory_hotplug(void)
60 mutex_unlock(&mem_hotplug_mutex
);
64 /* add this memory to iomem resource */
65 static struct resource
*register_memory_resource(u64 start
, u64 size
)
68 res
= kzalloc(sizeof(struct resource
), GFP_KERNEL
);
71 res
->name
= "System RAM";
73 res
->end
= start
+ size
- 1;
74 res
->flags
= IORESOURCE_MEM
| IORESOURCE_BUSY
;
75 if (request_resource(&iomem_resource
, res
) < 0) {
76 pr_debug("System RAM resource %pR cannot be added\n", res
);
83 static void release_memory_resource(struct resource
*res
)
87 release_resource(res
);
92 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
93 void get_page_bootmem(unsigned long info
, struct page
*page
,
96 page
->lru
.next
= (struct list_head
*) type
;
98 set_page_private(page
, info
);
99 atomic_inc(&page
->_count
);
102 void put_page_bootmem(struct page
*page
)
106 type
= (unsigned long) page
->lru
.next
;
107 BUG_ON(type
< MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE
||
108 type
> MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE
);
110 if (atomic_dec_return(&page
->_count
) == 1) {
111 ClearPagePrivate(page
);
112 set_page_private(page
, 0);
113 INIT_LIST_HEAD(&page
->lru
);
114 free_reserved_page(page
);
118 #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
119 #ifndef CONFIG_SPARSEMEM_VMEMMAP
120 static void register_page_bootmem_info_section(unsigned long start_pfn
)
122 unsigned long *usemap
, mapsize
, section_nr
, i
;
123 struct mem_section
*ms
;
124 struct page
*page
, *memmap
;
126 section_nr
= pfn_to_section_nr(start_pfn
);
127 ms
= __nr_to_section(section_nr
);
129 /* Get section's memmap address */
130 memmap
= sparse_decode_mem_map(ms
->section_mem_map
, section_nr
);
133 * Get page for the memmap's phys address
134 * XXX: need more consideration for sparse_vmemmap...
136 page
= virt_to_page(memmap
);
137 mapsize
= sizeof(struct page
) * PAGES_PER_SECTION
;
138 mapsize
= PAGE_ALIGN(mapsize
) >> PAGE_SHIFT
;
140 /* remember memmap's page */
141 for (i
= 0; i
< mapsize
; i
++, page
++)
142 get_page_bootmem(section_nr
, page
, SECTION_INFO
);
144 usemap
= __nr_to_section(section_nr
)->pageblock_flags
;
145 page
= virt_to_page(usemap
);
147 mapsize
= PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT
;
149 for (i
= 0; i
< mapsize
; i
++, page
++)
150 get_page_bootmem(section_nr
, page
, MIX_SECTION_INFO
);
153 #else /* CONFIG_SPARSEMEM_VMEMMAP */
154 static void register_page_bootmem_info_section(unsigned long start_pfn
)
156 unsigned long *usemap
, mapsize
, section_nr
, i
;
157 struct mem_section
*ms
;
158 struct page
*page
, *memmap
;
160 if (!pfn_valid(start_pfn
))
163 section_nr
= pfn_to_section_nr(start_pfn
);
164 ms
= __nr_to_section(section_nr
);
166 memmap
= sparse_decode_mem_map(ms
->section_mem_map
, section_nr
);
168 register_page_bootmem_memmap(section_nr
, memmap
, PAGES_PER_SECTION
);
170 usemap
= __nr_to_section(section_nr
)->pageblock_flags
;
171 page
= virt_to_page(usemap
);
173 mapsize
= PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT
;
175 for (i
= 0; i
< mapsize
; i
++, page
++)
176 get_page_bootmem(section_nr
, page
, MIX_SECTION_INFO
);
178 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
180 void register_page_bootmem_info_node(struct pglist_data
*pgdat
)
182 unsigned long i
, pfn
, end_pfn
, nr_pages
;
183 int node
= pgdat
->node_id
;
187 nr_pages
= PAGE_ALIGN(sizeof(struct pglist_data
)) >> PAGE_SHIFT
;
188 page
= virt_to_page(pgdat
);
190 for (i
= 0; i
< nr_pages
; i
++, page
++)
191 get_page_bootmem(node
, page
, NODE_INFO
);
193 zone
= &pgdat
->node_zones
[0];
194 for (; zone
< pgdat
->node_zones
+ MAX_NR_ZONES
- 1; zone
++) {
195 if (zone_is_initialized(zone
)) {
196 nr_pages
= zone
->wait_table_hash_nr_entries
197 * sizeof(wait_queue_head_t
);
198 nr_pages
= PAGE_ALIGN(nr_pages
) >> PAGE_SHIFT
;
199 page
= virt_to_page(zone
->wait_table
);
201 for (i
= 0; i
< nr_pages
; i
++, page
++)
202 get_page_bootmem(node
, page
, NODE_INFO
);
206 pfn
= pgdat
->node_start_pfn
;
207 end_pfn
= pgdat_end_pfn(pgdat
);
209 /* register section info */
210 for (; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
212 * Some platforms can assign the same pfn to multiple nodes - on
213 * node0 as well as nodeN. To avoid registering a pfn against
214 * multiple nodes we check that this pfn does not already
215 * reside in some other nodes.
217 if (pfn_valid(pfn
) && (pfn_to_nid(pfn
) == node
))
218 register_page_bootmem_info_section(pfn
);
221 #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */
223 static void grow_zone_span(struct zone
*zone
, unsigned long start_pfn
,
224 unsigned long end_pfn
)
226 unsigned long old_zone_end_pfn
;
228 zone_span_writelock(zone
);
230 old_zone_end_pfn
= zone_end_pfn(zone
);
231 if (zone_is_empty(zone
) || start_pfn
< zone
->zone_start_pfn
)
232 zone
->zone_start_pfn
= start_pfn
;
234 zone
->spanned_pages
= max(old_zone_end_pfn
, end_pfn
) -
235 zone
->zone_start_pfn
;
237 zone_span_writeunlock(zone
);
240 static void resize_zone(struct zone
*zone
, unsigned long start_pfn
,
241 unsigned long end_pfn
)
243 zone_span_writelock(zone
);
245 if (end_pfn
- start_pfn
) {
246 zone
->zone_start_pfn
= start_pfn
;
247 zone
->spanned_pages
= end_pfn
- start_pfn
;
250 * make it consist as free_area_init_core(),
251 * if spanned_pages = 0, then keep start_pfn = 0
253 zone
->zone_start_pfn
= 0;
254 zone
->spanned_pages
= 0;
257 zone_span_writeunlock(zone
);
260 static void fix_zone_id(struct zone
*zone
, unsigned long start_pfn
,
261 unsigned long end_pfn
)
263 enum zone_type zid
= zone_idx(zone
);
264 int nid
= zone
->zone_pgdat
->node_id
;
267 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
268 set_page_links(pfn_to_page(pfn
), zid
, nid
, pfn
);
271 /* Can fail with -ENOMEM from allocating a wait table with vmalloc() or
272 * alloc_bootmem_node_nopanic() */
273 static int __ref
ensure_zone_is_initialized(struct zone
*zone
,
274 unsigned long start_pfn
, unsigned long num_pages
)
276 if (!zone_is_initialized(zone
))
277 return init_currently_empty_zone(zone
, start_pfn
, num_pages
,
282 static int __meminit
move_pfn_range_left(struct zone
*z1
, struct zone
*z2
,
283 unsigned long start_pfn
, unsigned long end_pfn
)
287 unsigned long z1_start_pfn
;
289 ret
= ensure_zone_is_initialized(z1
, start_pfn
, end_pfn
- start_pfn
);
293 pgdat_resize_lock(z1
->zone_pgdat
, &flags
);
295 /* can't move pfns which are higher than @z2 */
296 if (end_pfn
> zone_end_pfn(z2
))
298 /* the move out part must be at the left most of @z2 */
299 if (start_pfn
> z2
->zone_start_pfn
)
301 /* must included/overlap */
302 if (end_pfn
<= z2
->zone_start_pfn
)
305 /* use start_pfn for z1's start_pfn if z1 is empty */
306 if (!zone_is_empty(z1
))
307 z1_start_pfn
= z1
->zone_start_pfn
;
309 z1_start_pfn
= start_pfn
;
311 resize_zone(z1
, z1_start_pfn
, end_pfn
);
312 resize_zone(z2
, end_pfn
, zone_end_pfn(z2
));
314 pgdat_resize_unlock(z1
->zone_pgdat
, &flags
);
316 fix_zone_id(z1
, start_pfn
, end_pfn
);
320 pgdat_resize_unlock(z1
->zone_pgdat
, &flags
);
324 static int __meminit
move_pfn_range_right(struct zone
*z1
, struct zone
*z2
,
325 unsigned long start_pfn
, unsigned long end_pfn
)
329 unsigned long z2_end_pfn
;
331 ret
= ensure_zone_is_initialized(z2
, start_pfn
, end_pfn
- start_pfn
);
335 pgdat_resize_lock(z1
->zone_pgdat
, &flags
);
337 /* can't move pfns which are lower than @z1 */
338 if (z1
->zone_start_pfn
> start_pfn
)
340 /* the move out part mast at the right most of @z1 */
341 if (zone_end_pfn(z1
) > end_pfn
)
343 /* must included/overlap */
344 if (start_pfn
>= zone_end_pfn(z1
))
347 /* use end_pfn for z2's end_pfn if z2 is empty */
348 if (!zone_is_empty(z2
))
349 z2_end_pfn
= zone_end_pfn(z2
);
351 z2_end_pfn
= end_pfn
;
353 resize_zone(z1
, z1
->zone_start_pfn
, start_pfn
);
354 resize_zone(z2
, start_pfn
, z2_end_pfn
);
356 pgdat_resize_unlock(z1
->zone_pgdat
, &flags
);
358 fix_zone_id(z2
, start_pfn
, end_pfn
);
362 pgdat_resize_unlock(z1
->zone_pgdat
, &flags
);
366 static void grow_pgdat_span(struct pglist_data
*pgdat
, unsigned long start_pfn
,
367 unsigned long end_pfn
)
369 unsigned long old_pgdat_end_pfn
= pgdat_end_pfn(pgdat
);
371 if (!pgdat
->node_spanned_pages
|| start_pfn
< pgdat
->node_start_pfn
)
372 pgdat
->node_start_pfn
= start_pfn
;
374 pgdat
->node_spanned_pages
= max(old_pgdat_end_pfn
, end_pfn
) -
375 pgdat
->node_start_pfn
;
378 static int __meminit
__add_zone(struct zone
*zone
, unsigned long phys_start_pfn
)
380 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
381 int nr_pages
= PAGES_PER_SECTION
;
382 int nid
= pgdat
->node_id
;
387 zone_type
= zone
- pgdat
->node_zones
;
388 ret
= ensure_zone_is_initialized(zone
, phys_start_pfn
, nr_pages
);
392 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
393 grow_zone_span(zone
, phys_start_pfn
, phys_start_pfn
+ nr_pages
);
394 grow_pgdat_span(zone
->zone_pgdat
, phys_start_pfn
,
395 phys_start_pfn
+ nr_pages
);
396 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
397 memmap_init_zone(nr_pages
, nid
, zone_type
,
398 phys_start_pfn
, MEMMAP_HOTPLUG
);
402 static int __meminit
__add_section(int nid
, struct zone
*zone
,
403 unsigned long phys_start_pfn
)
407 if (pfn_valid(phys_start_pfn
))
410 ret
= sparse_add_one_section(zone
, phys_start_pfn
);
415 ret
= __add_zone(zone
, phys_start_pfn
);
420 return register_new_memory(nid
, __pfn_to_section(phys_start_pfn
));
424 * Reasonably generic function for adding memory. It is
425 * expected that archs that support memory hotplug will
426 * call this function after deciding the zone to which to
429 int __ref
__add_pages(int nid
, struct zone
*zone
, unsigned long phys_start_pfn
,
430 unsigned long nr_pages
)
434 int start_sec
, end_sec
;
435 /* during initialize mem_map, align hot-added range to section */
436 start_sec
= pfn_to_section_nr(phys_start_pfn
);
437 end_sec
= pfn_to_section_nr(phys_start_pfn
+ nr_pages
- 1);
439 for (i
= start_sec
; i
<= end_sec
; i
++) {
440 err
= __add_section(nid
, zone
, i
<< PFN_SECTION_SHIFT
);
443 * EEXIST is finally dealt with by ioresource collision
444 * check. see add_memory() => register_memory_resource()
445 * Warning will be printed if there is collision.
447 if (err
&& (err
!= -EEXIST
))
454 EXPORT_SYMBOL_GPL(__add_pages
);
456 #ifdef CONFIG_MEMORY_HOTREMOVE
457 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */
458 static int find_smallest_section_pfn(int nid
, struct zone
*zone
,
459 unsigned long start_pfn
,
460 unsigned long end_pfn
)
462 struct mem_section
*ms
;
464 for (; start_pfn
< end_pfn
; start_pfn
+= PAGES_PER_SECTION
) {
465 ms
= __pfn_to_section(start_pfn
);
467 if (unlikely(!valid_section(ms
)))
470 if (unlikely(pfn_to_nid(start_pfn
) != nid
))
473 if (zone
&& zone
!= page_zone(pfn_to_page(start_pfn
)))
482 /* find the biggest valid pfn in the range [start_pfn, end_pfn). */
483 static int find_biggest_section_pfn(int nid
, struct zone
*zone
,
484 unsigned long start_pfn
,
485 unsigned long end_pfn
)
487 struct mem_section
*ms
;
490 /* pfn is the end pfn of a memory section. */
492 for (; pfn
>= start_pfn
; pfn
-= PAGES_PER_SECTION
) {
493 ms
= __pfn_to_section(pfn
);
495 if (unlikely(!valid_section(ms
)))
498 if (unlikely(pfn_to_nid(pfn
) != nid
))
501 if (zone
&& zone
!= page_zone(pfn_to_page(pfn
)))
510 static void shrink_zone_span(struct zone
*zone
, unsigned long start_pfn
,
511 unsigned long end_pfn
)
513 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
514 unsigned long z
= zone_end_pfn(zone
); /* zone_end_pfn namespace clash */
515 unsigned long zone_end_pfn
= z
;
517 struct mem_section
*ms
;
518 int nid
= zone_to_nid(zone
);
520 zone_span_writelock(zone
);
521 if (zone_start_pfn
== start_pfn
) {
523 * If the section is smallest section in the zone, it need
524 * shrink zone->zone_start_pfn and zone->zone_spanned_pages.
525 * In this case, we find second smallest valid mem_section
526 * for shrinking zone.
528 pfn
= find_smallest_section_pfn(nid
, zone
, end_pfn
,
531 zone
->zone_start_pfn
= pfn
;
532 zone
->spanned_pages
= zone_end_pfn
- pfn
;
534 } else if (zone_end_pfn
== end_pfn
) {
536 * If the section is biggest section in the zone, it need
537 * shrink zone->spanned_pages.
538 * In this case, we find second biggest valid mem_section for
541 pfn
= find_biggest_section_pfn(nid
, zone
, zone_start_pfn
,
544 zone
->spanned_pages
= pfn
- zone_start_pfn
+ 1;
548 * The section is not biggest or smallest mem_section in the zone, it
549 * only creates a hole in the zone. So in this case, we need not
550 * change the zone. But perhaps, the zone has only hole data. Thus
551 * it check the zone has only hole or not.
553 pfn
= zone_start_pfn
;
554 for (; pfn
< zone_end_pfn
; pfn
+= PAGES_PER_SECTION
) {
555 ms
= __pfn_to_section(pfn
);
557 if (unlikely(!valid_section(ms
)))
560 if (page_zone(pfn_to_page(pfn
)) != zone
)
563 /* If the section is current section, it continues the loop */
564 if (start_pfn
== pfn
)
567 /* If we find valid section, we have nothing to do */
568 zone_span_writeunlock(zone
);
572 /* The zone has no valid section */
573 zone
->zone_start_pfn
= 0;
574 zone
->spanned_pages
= 0;
575 zone_span_writeunlock(zone
);
578 static void shrink_pgdat_span(struct pglist_data
*pgdat
,
579 unsigned long start_pfn
, unsigned long end_pfn
)
581 unsigned long pgdat_start_pfn
= pgdat
->node_start_pfn
;
582 unsigned long p
= pgdat_end_pfn(pgdat
); /* pgdat_end_pfn namespace clash */
583 unsigned long pgdat_end_pfn
= p
;
585 struct mem_section
*ms
;
586 int nid
= pgdat
->node_id
;
588 if (pgdat_start_pfn
== start_pfn
) {
590 * If the section is smallest section in the pgdat, it need
591 * shrink pgdat->node_start_pfn and pgdat->node_spanned_pages.
592 * In this case, we find second smallest valid mem_section
593 * for shrinking zone.
595 pfn
= find_smallest_section_pfn(nid
, NULL
, end_pfn
,
598 pgdat
->node_start_pfn
= pfn
;
599 pgdat
->node_spanned_pages
= pgdat_end_pfn
- pfn
;
601 } else if (pgdat_end_pfn
== end_pfn
) {
603 * If the section is biggest section in the pgdat, it need
604 * shrink pgdat->node_spanned_pages.
605 * In this case, we find second biggest valid mem_section for
608 pfn
= find_biggest_section_pfn(nid
, NULL
, pgdat_start_pfn
,
611 pgdat
->node_spanned_pages
= pfn
- pgdat_start_pfn
+ 1;
615 * If the section is not biggest or smallest mem_section in the pgdat,
616 * it only creates a hole in the pgdat. So in this case, we need not
618 * But perhaps, the pgdat has only hole data. Thus it check the pgdat
619 * has only hole or not.
621 pfn
= pgdat_start_pfn
;
622 for (; pfn
< pgdat_end_pfn
; pfn
+= PAGES_PER_SECTION
) {
623 ms
= __pfn_to_section(pfn
);
625 if (unlikely(!valid_section(ms
)))
628 if (pfn_to_nid(pfn
) != nid
)
631 /* If the section is current section, it continues the loop */
632 if (start_pfn
== pfn
)
635 /* If we find valid section, we have nothing to do */
639 /* The pgdat has no valid section */
640 pgdat
->node_start_pfn
= 0;
641 pgdat
->node_spanned_pages
= 0;
644 static void __remove_zone(struct zone
*zone
, unsigned long start_pfn
)
646 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
647 int nr_pages
= PAGES_PER_SECTION
;
651 zone_type
= zone
- pgdat
->node_zones
;
653 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
654 shrink_zone_span(zone
, start_pfn
, start_pfn
+ nr_pages
);
655 shrink_pgdat_span(pgdat
, start_pfn
, start_pfn
+ nr_pages
);
656 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
659 static int __remove_section(struct zone
*zone
, struct mem_section
*ms
)
661 unsigned long start_pfn
;
665 if (!valid_section(ms
))
668 ret
= unregister_memory_section(ms
);
672 scn_nr
= __section_nr(ms
);
673 start_pfn
= section_nr_to_pfn(scn_nr
);
674 __remove_zone(zone
, start_pfn
);
676 sparse_remove_one_section(zone
, ms
);
681 * __remove_pages() - remove sections of pages from a zone
682 * @zone: zone from which pages need to be removed
683 * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
684 * @nr_pages: number of pages to remove (must be multiple of section size)
686 * Generic helper function to remove section mappings and sysfs entries
687 * for the section of the memory we are removing. Caller needs to make
688 * sure that pages are marked reserved and zones are adjust properly by
689 * calling offline_pages().
691 int __remove_pages(struct zone
*zone
, unsigned long phys_start_pfn
,
692 unsigned long nr_pages
)
695 int sections_to_remove
;
696 resource_size_t start
, size
;
700 * We can only remove entire sections
702 BUG_ON(phys_start_pfn
& ~PAGE_SECTION_MASK
);
703 BUG_ON(nr_pages
% PAGES_PER_SECTION
);
705 start
= phys_start_pfn
<< PAGE_SHIFT
;
706 size
= nr_pages
* PAGE_SIZE
;
707 ret
= release_mem_region_adjustable(&iomem_resource
, start
, size
);
709 resource_size_t endres
= start
+ size
- 1;
711 pr_warn("Unable to release resource <%pa-%pa> (%d)\n",
712 &start
, &endres
, ret
);
715 sections_to_remove
= nr_pages
/ PAGES_PER_SECTION
;
716 for (i
= 0; i
< sections_to_remove
; i
++) {
717 unsigned long pfn
= phys_start_pfn
+ i
*PAGES_PER_SECTION
;
718 ret
= __remove_section(zone
, __pfn_to_section(pfn
));
724 EXPORT_SYMBOL_GPL(__remove_pages
);
725 #endif /* CONFIG_MEMORY_HOTREMOVE */
727 int set_online_page_callback(online_page_callback_t callback
)
731 lock_memory_hotplug();
733 if (online_page_callback
== generic_online_page
) {
734 online_page_callback
= callback
;
738 unlock_memory_hotplug();
742 EXPORT_SYMBOL_GPL(set_online_page_callback
);
744 int restore_online_page_callback(online_page_callback_t callback
)
748 lock_memory_hotplug();
750 if (online_page_callback
== callback
) {
751 online_page_callback
= generic_online_page
;
755 unlock_memory_hotplug();
759 EXPORT_SYMBOL_GPL(restore_online_page_callback
);
761 void __online_page_set_limits(struct page
*page
)
764 EXPORT_SYMBOL_GPL(__online_page_set_limits
);
766 void __online_page_increment_counters(struct page
*page
)
768 adjust_managed_page_count(page
, 1);
770 EXPORT_SYMBOL_GPL(__online_page_increment_counters
);
772 void __online_page_free(struct page
*page
)
774 __free_reserved_page(page
);
776 EXPORT_SYMBOL_GPL(__online_page_free
);
778 static void generic_online_page(struct page
*page
)
780 __online_page_set_limits(page
);
781 __online_page_increment_counters(page
);
782 __online_page_free(page
);
785 static int online_pages_range(unsigned long start_pfn
, unsigned long nr_pages
,
789 unsigned long onlined_pages
= *(unsigned long *)arg
;
791 if (PageReserved(pfn_to_page(start_pfn
)))
792 for (i
= 0; i
< nr_pages
; i
++) {
793 page
= pfn_to_page(start_pfn
+ i
);
794 (*online_page_callback
)(page
);
797 *(unsigned long *)arg
= onlined_pages
;
801 #ifdef CONFIG_MOVABLE_NODE
803 * When CONFIG_MOVABLE_NODE, we permit onlining of a node which doesn't have
806 static bool can_online_high_movable(struct zone
*zone
)
810 #else /* CONFIG_MOVABLE_NODE */
811 /* ensure every online node has NORMAL memory */
812 static bool can_online_high_movable(struct zone
*zone
)
814 return node_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
816 #endif /* CONFIG_MOVABLE_NODE */
818 /* check which state of node_states will be changed when online memory */
819 static void node_states_check_changes_online(unsigned long nr_pages
,
820 struct zone
*zone
, struct memory_notify
*arg
)
822 int nid
= zone_to_nid(zone
);
823 enum zone_type zone_last
= ZONE_NORMAL
;
826 * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
827 * contains nodes which have zones of 0...ZONE_NORMAL,
828 * set zone_last to ZONE_NORMAL.
830 * If we don't have HIGHMEM nor movable node,
831 * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
832 * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
834 if (N_MEMORY
== N_NORMAL_MEMORY
)
835 zone_last
= ZONE_MOVABLE
;
838 * if the memory to be online is in a zone of 0...zone_last, and
839 * the zones of 0...zone_last don't have memory before online, we will
840 * need to set the node to node_states[N_NORMAL_MEMORY] after
841 * the memory is online.
843 if (zone_idx(zone
) <= zone_last
&& !node_state(nid
, N_NORMAL_MEMORY
))
844 arg
->status_change_nid_normal
= nid
;
846 arg
->status_change_nid_normal
= -1;
848 #ifdef CONFIG_HIGHMEM
850 * If we have movable node, node_states[N_HIGH_MEMORY]
851 * contains nodes which have zones of 0...ZONE_HIGHMEM,
852 * set zone_last to ZONE_HIGHMEM.
854 * If we don't have movable node, node_states[N_NORMAL_MEMORY]
855 * contains nodes which have zones of 0...ZONE_MOVABLE,
856 * set zone_last to ZONE_MOVABLE.
858 zone_last
= ZONE_HIGHMEM
;
859 if (N_MEMORY
== N_HIGH_MEMORY
)
860 zone_last
= ZONE_MOVABLE
;
862 if (zone_idx(zone
) <= zone_last
&& !node_state(nid
, N_HIGH_MEMORY
))
863 arg
->status_change_nid_high
= nid
;
865 arg
->status_change_nid_high
= -1;
867 arg
->status_change_nid_high
= arg
->status_change_nid_normal
;
871 * if the node don't have memory befor online, we will need to
872 * set the node to node_states[N_MEMORY] after the memory
875 if (!node_state(nid
, N_MEMORY
))
876 arg
->status_change_nid
= nid
;
878 arg
->status_change_nid
= -1;
881 static void node_states_set_node(int node
, struct memory_notify
*arg
)
883 if (arg
->status_change_nid_normal
>= 0)
884 node_set_state(node
, N_NORMAL_MEMORY
);
886 if (arg
->status_change_nid_high
>= 0)
887 node_set_state(node
, N_HIGH_MEMORY
);
889 node_set_state(node
, N_MEMORY
);
893 int __ref
online_pages(unsigned long pfn
, unsigned long nr_pages
, int online_type
)
896 unsigned long onlined_pages
= 0;
898 int need_zonelists_rebuild
= 0;
901 struct memory_notify arg
;
903 lock_memory_hotplug();
905 * This doesn't need a lock to do pfn_to_page().
906 * The section can't be removed here because of the
907 * memory_block->state_mutex.
909 zone
= page_zone(pfn_to_page(pfn
));
911 if ((zone_idx(zone
) > ZONE_NORMAL
|| online_type
== ONLINE_MOVABLE
) &&
912 !can_online_high_movable(zone
)) {
913 unlock_memory_hotplug();
917 if (online_type
== ONLINE_KERNEL
&& zone_idx(zone
) == ZONE_MOVABLE
) {
918 if (move_pfn_range_left(zone
- 1, zone
, pfn
, pfn
+ nr_pages
)) {
919 unlock_memory_hotplug();
923 if (online_type
== ONLINE_MOVABLE
&& zone_idx(zone
) == ZONE_MOVABLE
- 1) {
924 if (move_pfn_range_right(zone
, zone
+ 1, pfn
, pfn
+ nr_pages
)) {
925 unlock_memory_hotplug();
930 /* Previous code may changed the zone of the pfn range */
931 zone
= page_zone(pfn_to_page(pfn
));
934 arg
.nr_pages
= nr_pages
;
935 node_states_check_changes_online(nr_pages
, zone
, &arg
);
937 nid
= pfn_to_nid(pfn
);
939 ret
= memory_notify(MEM_GOING_ONLINE
, &arg
);
940 ret
= notifier_to_errno(ret
);
942 memory_notify(MEM_CANCEL_ONLINE
, &arg
);
943 unlock_memory_hotplug();
947 * If this zone is not populated, then it is not in zonelist.
948 * This means the page allocator ignores this zone.
949 * So, zonelist must be updated after online.
951 mutex_lock(&zonelists_mutex
);
952 if (!populated_zone(zone
)) {
953 need_zonelists_rebuild
= 1;
954 build_all_zonelists(NULL
, zone
);
957 ret
= walk_system_ram_range(pfn
, nr_pages
, &onlined_pages
,
960 if (need_zonelists_rebuild
)
961 zone_pcp_reset(zone
);
962 mutex_unlock(&zonelists_mutex
);
963 printk(KERN_DEBUG
"online_pages [mem %#010llx-%#010llx] failed\n",
964 (unsigned long long) pfn
<< PAGE_SHIFT
,
965 (((unsigned long long) pfn
+ nr_pages
)
967 memory_notify(MEM_CANCEL_ONLINE
, &arg
);
968 unlock_memory_hotplug();
972 zone
->present_pages
+= onlined_pages
;
974 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
975 zone
->zone_pgdat
->node_present_pages
+= onlined_pages
;
976 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
979 node_states_set_node(zone_to_nid(zone
), &arg
);
980 if (need_zonelists_rebuild
)
981 build_all_zonelists(NULL
, NULL
);
983 zone_pcp_update(zone
);
986 mutex_unlock(&zonelists_mutex
);
988 init_per_zone_wmark_min();
991 kswapd_run(zone_to_nid(zone
));
993 vm_total_pages
= nr_free_pagecache_pages();
995 writeback_set_ratelimit();
998 memory_notify(MEM_ONLINE
, &arg
);
999 unlock_memory_hotplug();
1003 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
1005 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
1006 static pg_data_t __ref
*hotadd_new_pgdat(int nid
, u64 start
)
1008 struct pglist_data
*pgdat
;
1009 unsigned long zones_size
[MAX_NR_ZONES
] = {0};
1010 unsigned long zholes_size
[MAX_NR_ZONES
] = {0};
1011 unsigned long start_pfn
= start
>> PAGE_SHIFT
;
1013 pgdat
= NODE_DATA(nid
);
1015 pgdat
= arch_alloc_nodedata(nid
);
1019 arch_refresh_nodedata(nid
, pgdat
);
1022 /* we can use NODE_DATA(nid) from here */
1024 /* init node's zones as empty zones, we don't have any present pages.*/
1025 free_area_init_node(nid
, zones_size
, start_pfn
, zholes_size
);
1028 * The node we allocated has no zone fallback lists. For avoiding
1029 * to access not-initialized zonelist, build here.
1031 mutex_lock(&zonelists_mutex
);
1032 build_all_zonelists(pgdat
, NULL
);
1033 mutex_unlock(&zonelists_mutex
);
1038 static void rollback_node_hotadd(int nid
, pg_data_t
*pgdat
)
1040 arch_refresh_nodedata(nid
, NULL
);
1041 arch_free_nodedata(pgdat
);
1047 * try_online_node - online a node if offlined
1049 * called by cpu_up() to online a node without onlined memory.
1051 int try_online_node(int nid
)
1056 if (node_online(nid
))
1059 lock_memory_hotplug();
1060 pgdat
= hotadd_new_pgdat(nid
, 0);
1062 pr_err("Cannot online node %d due to NULL pgdat\n", nid
);
1066 node_set_online(nid
);
1067 ret
= register_one_node(nid
);
1070 if (pgdat
->node_zonelists
->_zonerefs
->zone
== NULL
) {
1071 mutex_lock(&zonelists_mutex
);
1072 build_all_zonelists(NULL
, NULL
);
1073 mutex_unlock(&zonelists_mutex
);
1077 unlock_memory_hotplug();
1081 static int check_hotplug_memory_range(u64 start
, u64 size
)
1083 u64 start_pfn
= start
>> PAGE_SHIFT
;
1084 u64 nr_pages
= size
>> PAGE_SHIFT
;
1086 /* Memory range must be aligned with section */
1087 if ((start_pfn
& ~PAGE_SECTION_MASK
) ||
1088 (nr_pages
% PAGES_PER_SECTION
) || (!nr_pages
)) {
1089 pr_err("Section-unaligned hotplug range: start 0x%llx, size 0x%llx\n",
1090 (unsigned long long)start
,
1091 (unsigned long long)size
);
1098 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
1099 int __ref
add_memory(int nid
, u64 start
, u64 size
)
1101 pg_data_t
*pgdat
= NULL
;
1104 struct resource
*res
;
1107 ret
= check_hotplug_memory_range(start
, size
);
1111 lock_memory_hotplug();
1113 res
= register_memory_resource(start
, size
);
1118 { /* Stupid hack to suppress address-never-null warning */
1119 void *p
= NODE_DATA(nid
);
1122 new_node
= !node_online(nid
);
1124 pgdat
= hotadd_new_pgdat(nid
, start
);
1130 /* call arch's memory hotadd */
1131 ret
= arch_add_memory(nid
, start
, size
);
1136 /* we online node here. we can't roll back from here. */
1137 node_set_online(nid
);
1140 ret
= register_one_node(nid
);
1142 * If sysfs file of new node can't create, cpu on the node
1143 * can't be hot-added. There is no rollback way now.
1144 * So, check by BUG_ON() to catch it reluctantly..
1149 /* create new memmap entry */
1150 firmware_map_add_hotplug(start
, start
+ size
, "System RAM");
1155 /* rollback pgdat allocation and others */
1157 rollback_node_hotadd(nid
, pgdat
);
1158 release_memory_resource(res
);
1161 unlock_memory_hotplug();
1164 EXPORT_SYMBOL_GPL(add_memory
);
1166 #ifdef CONFIG_MEMORY_HOTREMOVE
1168 * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
1169 * set and the size of the free page is given by page_order(). Using this,
1170 * the function determines if the pageblock contains only free pages.
1171 * Due to buddy contraints, a free page at least the size of a pageblock will
1172 * be located at the start of the pageblock
1174 static inline int pageblock_free(struct page
*page
)
1176 return PageBuddy(page
) && page_order(page
) >= pageblock_order
;
1179 /* Return the start of the next active pageblock after a given page */
1180 static struct page
*next_active_pageblock(struct page
*page
)
1182 /* Ensure the starting page is pageblock-aligned */
1183 BUG_ON(page_to_pfn(page
) & (pageblock_nr_pages
- 1));
1185 /* If the entire pageblock is free, move to the end of free page */
1186 if (pageblock_free(page
)) {
1188 /* be careful. we don't have locks, page_order can be changed.*/
1189 order
= page_order(page
);
1190 if ((order
< MAX_ORDER
) && (order
>= pageblock_order
))
1191 return page
+ (1 << order
);
1194 return page
+ pageblock_nr_pages
;
1197 /* Checks if this range of memory is likely to be hot-removable. */
1198 int is_mem_section_removable(unsigned long start_pfn
, unsigned long nr_pages
)
1200 struct page
*page
= pfn_to_page(start_pfn
);
1201 struct page
*end_page
= page
+ nr_pages
;
1203 /* Check the starting page of each pageblock within the range */
1204 for (; page
< end_page
; page
= next_active_pageblock(page
)) {
1205 if (!is_pageblock_removable_nolock(page
))
1210 /* All pageblocks in the memory block are likely to be hot-removable */
1215 * Confirm all pages in a range [start, end) is belongs to the same zone.
1217 static int test_pages_in_a_zone(unsigned long start_pfn
, unsigned long end_pfn
)
1220 struct zone
*zone
= NULL
;
1223 for (pfn
= start_pfn
;
1225 pfn
+= MAX_ORDER_NR_PAGES
) {
1227 /* This is just a CONFIG_HOLES_IN_ZONE check.*/
1228 while ((i
< MAX_ORDER_NR_PAGES
) && !pfn_valid_within(pfn
+ i
))
1230 if (i
== MAX_ORDER_NR_PAGES
)
1232 page
= pfn_to_page(pfn
+ i
);
1233 if (zone
&& page_zone(page
) != zone
)
1235 zone
= page_zone(page
);
1241 * Scan pfn range [start,end) to find movable/migratable pages (LRU pages
1242 * and hugepages). We scan pfn because it's much easier than scanning over
1243 * linked list. This function returns the pfn of the first found movable
1244 * page if it's found, otherwise 0.
1246 static unsigned long scan_movable_pages(unsigned long start
, unsigned long end
)
1250 for (pfn
= start
; pfn
< end
; pfn
++) {
1251 if (pfn_valid(pfn
)) {
1252 page
= pfn_to_page(pfn
);
1255 if (PageHuge(page
)) {
1256 if (is_hugepage_active(page
))
1259 pfn
= round_up(pfn
+ 1,
1260 1 << compound_order(page
)) - 1;
1267 #define NR_OFFLINE_AT_ONCE_PAGES (256)
1269 do_migrate_range(unsigned long start_pfn
, unsigned long end_pfn
)
1273 int move_pages
= NR_OFFLINE_AT_ONCE_PAGES
;
1274 int not_managed
= 0;
1278 for (pfn
= start_pfn
; pfn
< end_pfn
&& move_pages
> 0; pfn
++) {
1279 if (!pfn_valid(pfn
))
1281 page
= pfn_to_page(pfn
);
1283 if (PageHuge(page
)) {
1284 struct page
*head
= compound_head(page
);
1285 pfn
= page_to_pfn(head
) + (1<<compound_order(head
)) - 1;
1286 if (compound_order(head
) > PFN_SECTION_SHIFT
) {
1290 if (isolate_huge_page(page
, &source
))
1291 move_pages
-= 1 << compound_order(head
);
1295 if (!get_page_unless_zero(page
))
1298 * We can skip free pages. And we can only deal with pages on
1301 ret
= isolate_lru_page(page
);
1302 if (!ret
) { /* Success */
1304 list_add_tail(&page
->lru
, &source
);
1306 inc_zone_page_state(page
, NR_ISOLATED_ANON
+
1307 page_is_file_cache(page
));
1310 #ifdef CONFIG_DEBUG_VM
1311 printk(KERN_ALERT
"removing pfn %lx from LRU failed\n",
1316 /* Because we don't have big zone->lock. we should
1317 check this again here. */
1318 if (page_count(page
)) {
1325 if (!list_empty(&source
)) {
1327 putback_movable_pages(&source
);
1332 * alloc_migrate_target should be improooooved!!
1333 * migrate_pages returns # of failed pages.
1335 ret
= migrate_pages(&source
, alloc_migrate_target
, 0,
1336 MIGRATE_SYNC
, MR_MEMORY_HOTPLUG
);
1338 putback_movable_pages(&source
);
1345 * remove from free_area[] and mark all as Reserved.
1348 offline_isolated_pages_cb(unsigned long start
, unsigned long nr_pages
,
1351 __offline_isolated_pages(start
, start
+ nr_pages
);
1356 offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
1358 walk_system_ram_range(start_pfn
, end_pfn
- start_pfn
, NULL
,
1359 offline_isolated_pages_cb
);
1363 * Check all pages in range, recoreded as memory resource, are isolated.
1366 check_pages_isolated_cb(unsigned long start_pfn
, unsigned long nr_pages
,
1370 long offlined
= *(long *)data
;
1371 ret
= test_pages_isolated(start_pfn
, start_pfn
+ nr_pages
, true);
1372 offlined
= nr_pages
;
1374 *(long *)data
+= offlined
;
1379 check_pages_isolated(unsigned long start_pfn
, unsigned long end_pfn
)
1384 ret
= walk_system_ram_range(start_pfn
, end_pfn
- start_pfn
, &offlined
,
1385 check_pages_isolated_cb
);
1387 offlined
= (long)ret
;
1391 #ifdef CONFIG_MOVABLE_NODE
1393 * When CONFIG_MOVABLE_NODE, we permit offlining of a node which doesn't have
1396 static bool can_offline_normal(struct zone
*zone
, unsigned long nr_pages
)
1400 #else /* CONFIG_MOVABLE_NODE */
1401 /* ensure the node has NORMAL memory if it is still online */
1402 static bool can_offline_normal(struct zone
*zone
, unsigned long nr_pages
)
1404 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
1405 unsigned long present_pages
= 0;
1408 for (zt
= 0; zt
<= ZONE_NORMAL
; zt
++)
1409 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1411 if (present_pages
> nr_pages
)
1415 for (; zt
<= ZONE_MOVABLE
; zt
++)
1416 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1419 * we can't offline the last normal memory until all
1420 * higher memory is offlined.
1422 return present_pages
== 0;
1424 #endif /* CONFIG_MOVABLE_NODE */
1426 static int __init
cmdline_parse_movable_node(char *p
)
1428 #ifdef CONFIG_MOVABLE_NODE
1430 * Memory used by the kernel cannot be hot-removed because Linux
1431 * cannot migrate the kernel pages. When memory hotplug is
1432 * enabled, we should prevent memblock from allocating memory
1435 * ACPI SRAT records all hotpluggable memory ranges. But before
1436 * SRAT is parsed, we don't know about it.
1438 * The kernel image is loaded into memory at very early time. We
1439 * cannot prevent this anyway. So on NUMA system, we set any
1440 * node the kernel resides in as un-hotpluggable.
1442 * Since on modern servers, one node could have double-digit
1443 * gigabytes memory, we can assume the memory around the kernel
1444 * image is also un-hotpluggable. So before SRAT is parsed, just
1445 * allocate memory near the kernel image to try the best to keep
1446 * the kernel away from hotpluggable memory.
1448 memblock_set_bottom_up(true);
1450 pr_warn("movable_node option not supported\n");
1454 early_param("movable_node", cmdline_parse_movable_node
);
1456 /* check which state of node_states will be changed when offline memory */
1457 static void node_states_check_changes_offline(unsigned long nr_pages
,
1458 struct zone
*zone
, struct memory_notify
*arg
)
1460 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
1461 unsigned long present_pages
= 0;
1462 enum zone_type zt
, zone_last
= ZONE_NORMAL
;
1465 * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
1466 * contains nodes which have zones of 0...ZONE_NORMAL,
1467 * set zone_last to ZONE_NORMAL.
1469 * If we don't have HIGHMEM nor movable node,
1470 * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
1471 * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
1473 if (N_MEMORY
== N_NORMAL_MEMORY
)
1474 zone_last
= ZONE_MOVABLE
;
1477 * check whether node_states[N_NORMAL_MEMORY] will be changed.
1478 * If the memory to be offline is in a zone of 0...zone_last,
1479 * and it is the last present memory, 0...zone_last will
1480 * become empty after offline , thus we can determind we will
1481 * need to clear the node from node_states[N_NORMAL_MEMORY].
1483 for (zt
= 0; zt
<= zone_last
; zt
++)
1484 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1485 if (zone_idx(zone
) <= zone_last
&& nr_pages
>= present_pages
)
1486 arg
->status_change_nid_normal
= zone_to_nid(zone
);
1488 arg
->status_change_nid_normal
= -1;
1490 #ifdef CONFIG_HIGHMEM
1492 * If we have movable node, node_states[N_HIGH_MEMORY]
1493 * contains nodes which have zones of 0...ZONE_HIGHMEM,
1494 * set zone_last to ZONE_HIGHMEM.
1496 * If we don't have movable node, node_states[N_NORMAL_MEMORY]
1497 * contains nodes which have zones of 0...ZONE_MOVABLE,
1498 * set zone_last to ZONE_MOVABLE.
1500 zone_last
= ZONE_HIGHMEM
;
1501 if (N_MEMORY
== N_HIGH_MEMORY
)
1502 zone_last
= ZONE_MOVABLE
;
1504 for (; zt
<= zone_last
; zt
++)
1505 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1506 if (zone_idx(zone
) <= zone_last
&& nr_pages
>= present_pages
)
1507 arg
->status_change_nid_high
= zone_to_nid(zone
);
1509 arg
->status_change_nid_high
= -1;
1511 arg
->status_change_nid_high
= arg
->status_change_nid_normal
;
1515 * node_states[N_HIGH_MEMORY] contains nodes which have 0...ZONE_MOVABLE
1517 zone_last
= ZONE_MOVABLE
;
1520 * check whether node_states[N_HIGH_MEMORY] will be changed
1521 * If we try to offline the last present @nr_pages from the node,
1522 * we can determind we will need to clear the node from
1523 * node_states[N_HIGH_MEMORY].
1525 for (; zt
<= zone_last
; zt
++)
1526 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1527 if (nr_pages
>= present_pages
)
1528 arg
->status_change_nid
= zone_to_nid(zone
);
1530 arg
->status_change_nid
= -1;
1533 static void node_states_clear_node(int node
, struct memory_notify
*arg
)
1535 if (arg
->status_change_nid_normal
>= 0)
1536 node_clear_state(node
, N_NORMAL_MEMORY
);
1538 if ((N_MEMORY
!= N_NORMAL_MEMORY
) &&
1539 (arg
->status_change_nid_high
>= 0))
1540 node_clear_state(node
, N_HIGH_MEMORY
);
1542 if ((N_MEMORY
!= N_HIGH_MEMORY
) &&
1543 (arg
->status_change_nid
>= 0))
1544 node_clear_state(node
, N_MEMORY
);
1547 static int __ref
__offline_pages(unsigned long start_pfn
,
1548 unsigned long end_pfn
, unsigned long timeout
)
1550 unsigned long pfn
, nr_pages
, expire
;
1551 long offlined_pages
;
1552 int ret
, drain
, retry_max
, node
;
1553 unsigned long flags
;
1555 struct memory_notify arg
;
1557 /* at least, alignment against pageblock is necessary */
1558 if (!IS_ALIGNED(start_pfn
, pageblock_nr_pages
))
1560 if (!IS_ALIGNED(end_pfn
, pageblock_nr_pages
))
1562 /* This makes hotplug much easier...and readable.
1563 we assume this for now. .*/
1564 if (!test_pages_in_a_zone(start_pfn
, end_pfn
))
1567 lock_memory_hotplug();
1569 zone
= page_zone(pfn_to_page(start_pfn
));
1570 node
= zone_to_nid(zone
);
1571 nr_pages
= end_pfn
- start_pfn
;
1574 if (zone_idx(zone
) <= ZONE_NORMAL
&& !can_offline_normal(zone
, nr_pages
))
1577 /* set above range as isolated */
1578 ret
= start_isolate_page_range(start_pfn
, end_pfn
,
1579 MIGRATE_MOVABLE
, true);
1583 arg
.start_pfn
= start_pfn
;
1584 arg
.nr_pages
= nr_pages
;
1585 node_states_check_changes_offline(nr_pages
, zone
, &arg
);
1587 ret
= memory_notify(MEM_GOING_OFFLINE
, &arg
);
1588 ret
= notifier_to_errno(ret
);
1590 goto failed_removal
;
1593 expire
= jiffies
+ timeout
;
1597 /* start memory hot removal */
1599 if (time_after(jiffies
, expire
))
1600 goto failed_removal
;
1602 if (signal_pending(current
))
1603 goto failed_removal
;
1606 lru_add_drain_all();
1611 pfn
= scan_movable_pages(start_pfn
, end_pfn
);
1612 if (pfn
) { /* We have movable pages */
1613 ret
= do_migrate_range(pfn
, end_pfn
);
1619 if (--retry_max
== 0)
1620 goto failed_removal
;
1626 /* drain all zone's lru pagevec, this is asynchronous... */
1627 lru_add_drain_all();
1629 /* drain pcp pages, this is synchronous. */
1632 * dissolve free hugepages in the memory block before doing offlining
1633 * actually in order to make hugetlbfs's object counting consistent.
1635 dissolve_free_huge_pages(start_pfn
, end_pfn
);
1637 offlined_pages
= check_pages_isolated(start_pfn
, end_pfn
);
1638 if (offlined_pages
< 0) {
1640 goto failed_removal
;
1642 printk(KERN_INFO
"Offlined Pages %ld\n", offlined_pages
);
1643 /* Ok, all of our target is isolated.
1644 We cannot do rollback at this point. */
1645 offline_isolated_pages(start_pfn
, end_pfn
);
1646 /* reset pagetype flags and makes migrate type to be MOVABLE */
1647 undo_isolate_page_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
);
1648 /* removal success */
1649 adjust_managed_page_count(pfn_to_page(start_pfn
), -offlined_pages
);
1650 zone
->present_pages
-= offlined_pages
;
1652 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
1653 zone
->zone_pgdat
->node_present_pages
-= offlined_pages
;
1654 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
1656 init_per_zone_wmark_min();
1658 if (!populated_zone(zone
)) {
1659 zone_pcp_reset(zone
);
1660 mutex_lock(&zonelists_mutex
);
1661 build_all_zonelists(NULL
, NULL
);
1662 mutex_unlock(&zonelists_mutex
);
1664 zone_pcp_update(zone
);
1666 node_states_clear_node(node
, &arg
);
1667 if (arg
.status_change_nid
>= 0)
1670 vm_total_pages
= nr_free_pagecache_pages();
1671 writeback_set_ratelimit();
1673 memory_notify(MEM_OFFLINE
, &arg
);
1674 unlock_memory_hotplug();
1678 printk(KERN_INFO
"memory offlining [mem %#010llx-%#010llx] failed\n",
1679 (unsigned long long) start_pfn
<< PAGE_SHIFT
,
1680 ((unsigned long long) end_pfn
<< PAGE_SHIFT
) - 1);
1681 memory_notify(MEM_CANCEL_OFFLINE
, &arg
);
1682 /* pushback to free area */
1683 undo_isolate_page_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
);
1686 unlock_memory_hotplug();
1690 int offline_pages(unsigned long start_pfn
, unsigned long nr_pages
)
1692 return __offline_pages(start_pfn
, start_pfn
+ nr_pages
, 120 * HZ
);
1694 #endif /* CONFIG_MEMORY_HOTREMOVE */
1697 * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn)
1698 * @start_pfn: start pfn of the memory range
1699 * @end_pfn: end pfn of the memory range
1700 * @arg: argument passed to func
1701 * @func: callback for each memory section walked
1703 * This function walks through all present mem sections in range
1704 * [start_pfn, end_pfn) and call func on each mem section.
1706 * Returns the return value of func.
1708 int walk_memory_range(unsigned long start_pfn
, unsigned long end_pfn
,
1709 void *arg
, int (*func
)(struct memory_block
*, void *))
1711 struct memory_block
*mem
= NULL
;
1712 struct mem_section
*section
;
1713 unsigned long pfn
, section_nr
;
1716 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
1717 section_nr
= pfn_to_section_nr(pfn
);
1718 if (!present_section_nr(section_nr
))
1721 section
= __nr_to_section(section_nr
);
1722 /* same memblock? */
1724 if ((section_nr
>= mem
->start_section_nr
) &&
1725 (section_nr
<= mem
->end_section_nr
))
1728 mem
= find_memory_block_hinted(section
, mem
);
1732 ret
= func(mem
, arg
);
1734 kobject_put(&mem
->dev
.kobj
);
1740 kobject_put(&mem
->dev
.kobj
);
1745 #ifdef CONFIG_MEMORY_HOTREMOVE
1746 static int check_memblock_offlined_cb(struct memory_block
*mem
, void *arg
)
1748 int ret
= !is_memblock_offlined(mem
);
1750 if (unlikely(ret
)) {
1751 phys_addr_t beginpa
, endpa
;
1753 beginpa
= PFN_PHYS(section_nr_to_pfn(mem
->start_section_nr
));
1754 endpa
= PFN_PHYS(section_nr_to_pfn(mem
->end_section_nr
+ 1))-1;
1755 pr_warn("removing memory fails, because memory "
1756 "[%pa-%pa] is onlined\n",
1763 static int check_cpu_on_node(pg_data_t
*pgdat
)
1767 for_each_present_cpu(cpu
) {
1768 if (cpu_to_node(cpu
) == pgdat
->node_id
)
1770 * the cpu on this node isn't removed, and we can't
1771 * offline this node.
1779 static void unmap_cpu_on_node(pg_data_t
*pgdat
)
1781 #ifdef CONFIG_ACPI_NUMA
1784 for_each_possible_cpu(cpu
)
1785 if (cpu_to_node(cpu
) == pgdat
->node_id
)
1786 numa_clear_node(cpu
);
1790 static int check_and_unmap_cpu_on_node(pg_data_t
*pgdat
)
1794 ret
= check_cpu_on_node(pgdat
);
1799 * the node will be offlined when we come here, so we can clear
1800 * the cpu_to_node() now.
1803 unmap_cpu_on_node(pgdat
);
1810 * Offline a node if all memory sections and cpus of the node are removed.
1812 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
1813 * and online/offline operations before this call.
1815 void try_offline_node(int nid
)
1817 pg_data_t
*pgdat
= NODE_DATA(nid
);
1818 unsigned long start_pfn
= pgdat
->node_start_pfn
;
1819 unsigned long end_pfn
= start_pfn
+ pgdat
->node_spanned_pages
;
1821 struct page
*pgdat_page
= virt_to_page(pgdat
);
1824 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
1825 unsigned long section_nr
= pfn_to_section_nr(pfn
);
1827 if (!present_section_nr(section_nr
))
1830 if (pfn_to_nid(pfn
) != nid
)
1834 * some memory sections of this node are not removed, and we
1835 * can't offline node now.
1840 if (check_and_unmap_cpu_on_node(pgdat
))
1844 * all memory/cpu of this node are removed, we can offline this
1847 node_set_offline(nid
);
1848 unregister_one_node(nid
);
1850 if (!PageSlab(pgdat_page
) && !PageCompound(pgdat_page
))
1851 /* node data is allocated from boot memory */
1854 /* free waittable in each zone */
1855 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
1856 struct zone
*zone
= pgdat
->node_zones
+ i
;
1859 * wait_table may be allocated from boot memory,
1860 * here only free if it's allocated by vmalloc.
1862 if (is_vmalloc_addr(zone
->wait_table
))
1863 vfree(zone
->wait_table
);
1867 * Since there is no way to guarentee the address of pgdat/zone is not
1868 * on stack of any kernel threads or used by other kernel objects
1869 * without reference counting or other symchronizing method, do not
1870 * reset node_data and free pgdat here. Just reset it to 0 and reuse
1871 * the memory when the node is online again.
1873 memset(pgdat
, 0, sizeof(*pgdat
));
1875 EXPORT_SYMBOL(try_offline_node
);
1880 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
1881 * and online/offline operations before this call, as required by
1882 * try_offline_node().
1884 void __ref
remove_memory(int nid
, u64 start
, u64 size
)
1888 BUG_ON(check_hotplug_memory_range(start
, size
));
1890 lock_memory_hotplug();
1893 * All memory blocks must be offlined before removing memory. Check
1894 * whether all memory blocks in question are offline and trigger a BUG()
1895 * if this is not the case.
1897 ret
= walk_memory_range(PFN_DOWN(start
), PFN_UP(start
+ size
- 1), NULL
,
1898 check_memblock_offlined_cb
);
1900 unlock_memory_hotplug();
1904 /* remove memmap entry */
1905 firmware_map_remove(start
, start
+ size
, "System RAM");
1907 arch_remove_memory(start
, size
);
1909 try_offline_node(nid
);
1911 unlock_memory_hotplug();
1913 EXPORT_SYMBOL_GPL(remove_memory
);
1914 #endif /* CONFIG_MEMORY_HOTREMOVE */