2 * linux/mm/memory_hotplug.c
7 #include <linux/stddef.h>
9 #include <linux/sched/signal.h>
10 #include <linux/swap.h>
11 #include <linux/interrupt.h>
12 #include <linux/pagemap.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/memremap.h>
22 #include <linux/memory_hotplug.h>
23 #include <linux/highmem.h>
24 #include <linux/vmalloc.h>
25 #include <linux/ioport.h>
26 #include <linux/delay.h>
27 #include <linux/migrate.h>
28 #include <linux/page-isolation.h>
29 #include <linux/pfn.h>
30 #include <linux/suspend.h>
31 #include <linux/mm_inline.h>
32 #include <linux/firmware-map.h>
33 #include <linux/stop_machine.h>
34 #include <linux/hugetlb.h>
35 #include <linux/memblock.h>
36 #include <linux/compaction.h>
38 #include <asm/tlbflush.h>
43 * online_page_callback contains pointer to current page onlining function.
44 * Initially it is generic_online_page(). If it is required it could be
45 * changed by calling set_online_page_callback() for callback registration
46 * and restore_online_page_callback() for generic callback restore.
49 static void generic_online_page(struct page
*page
);
51 static online_page_callback_t online_page_callback
= generic_online_page
;
52 static DEFINE_MUTEX(online_page_callback_lock
);
54 DEFINE_STATIC_PERCPU_RWSEM(mem_hotplug_lock
);
56 void get_online_mems(void)
58 percpu_down_read(&mem_hotplug_lock
);
61 void put_online_mems(void)
63 percpu_up_read(&mem_hotplug_lock
);
66 bool movable_node_enabled
= false;
68 #ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE
69 bool memhp_auto_online
;
71 bool memhp_auto_online
= true;
73 EXPORT_SYMBOL_GPL(memhp_auto_online
);
75 static int __init
setup_memhp_default_state(char *str
)
77 if (!strcmp(str
, "online"))
78 memhp_auto_online
= true;
79 else if (!strcmp(str
, "offline"))
80 memhp_auto_online
= false;
84 __setup("memhp_default_state=", setup_memhp_default_state
);
86 void mem_hotplug_begin(void)
89 percpu_down_write(&mem_hotplug_lock
);
92 void mem_hotplug_done(void)
94 percpu_up_write(&mem_hotplug_lock
);
98 /* add this memory to iomem resource */
99 static struct resource
*register_memory_resource(u64 start
, u64 size
)
101 struct resource
*res
, *conflict
;
102 res
= kzalloc(sizeof(struct resource
), GFP_KERNEL
);
104 return ERR_PTR(-ENOMEM
);
106 res
->name
= "System RAM";
108 res
->end
= start
+ size
- 1;
109 res
->flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
110 conflict
= request_resource_conflict(&iomem_resource
, res
);
112 if (conflict
->desc
== IORES_DESC_DEVICE_PRIVATE_MEMORY
) {
113 pr_debug("Device unaddressable memory block "
114 "memory hotplug at %#010llx !\n",
115 (unsigned long long)start
);
117 pr_debug("System RAM resource %pR cannot be added\n", res
);
119 return ERR_PTR(-EEXIST
);
124 static void release_memory_resource(struct resource
*res
)
128 release_resource(res
);
133 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
134 void get_page_bootmem(unsigned long info
, struct page
*page
,
137 page
->freelist
= (void *)type
;
138 SetPagePrivate(page
);
139 set_page_private(page
, info
);
143 void put_page_bootmem(struct page
*page
)
147 type
= (unsigned long) page
->freelist
;
148 BUG_ON(type
< MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE
||
149 type
> MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE
);
151 if (page_ref_dec_return(page
) == 1) {
152 page
->freelist
= NULL
;
153 ClearPagePrivate(page
);
154 set_page_private(page
, 0);
155 INIT_LIST_HEAD(&page
->lru
);
156 free_reserved_page(page
);
160 #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
161 #ifndef CONFIG_SPARSEMEM_VMEMMAP
162 static void register_page_bootmem_info_section(unsigned long start_pfn
)
164 unsigned long *usemap
, mapsize
, section_nr
, i
;
165 struct mem_section
*ms
;
166 struct page
*page
, *memmap
;
168 section_nr
= pfn_to_section_nr(start_pfn
);
169 ms
= __nr_to_section(section_nr
);
171 /* Get section's memmap address */
172 memmap
= sparse_decode_mem_map(ms
->section_mem_map
, section_nr
);
175 * Get page for the memmap's phys address
176 * XXX: need more consideration for sparse_vmemmap...
178 page
= virt_to_page(memmap
);
179 mapsize
= sizeof(struct page
) * PAGES_PER_SECTION
;
180 mapsize
= PAGE_ALIGN(mapsize
) >> PAGE_SHIFT
;
182 /* remember memmap's page */
183 for (i
= 0; i
< mapsize
; i
++, page
++)
184 get_page_bootmem(section_nr
, page
, SECTION_INFO
);
186 usemap
= ms
->pageblock_flags
;
187 page
= virt_to_page(usemap
);
189 mapsize
= PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT
;
191 for (i
= 0; i
< mapsize
; i
++, page
++)
192 get_page_bootmem(section_nr
, page
, MIX_SECTION_INFO
);
195 #else /* CONFIG_SPARSEMEM_VMEMMAP */
196 static void register_page_bootmem_info_section(unsigned long start_pfn
)
198 unsigned long *usemap
, mapsize
, section_nr
, i
;
199 struct mem_section
*ms
;
200 struct page
*page
, *memmap
;
202 section_nr
= pfn_to_section_nr(start_pfn
);
203 ms
= __nr_to_section(section_nr
);
205 memmap
= sparse_decode_mem_map(ms
->section_mem_map
, section_nr
);
207 register_page_bootmem_memmap(section_nr
, memmap
, PAGES_PER_SECTION
);
209 usemap
= ms
->pageblock_flags
;
210 page
= virt_to_page(usemap
);
212 mapsize
= PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT
;
214 for (i
= 0; i
< mapsize
; i
++, page
++)
215 get_page_bootmem(section_nr
, page
, MIX_SECTION_INFO
);
217 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
219 void __init
register_page_bootmem_info_node(struct pglist_data
*pgdat
)
221 unsigned long i
, pfn
, end_pfn
, nr_pages
;
222 int node
= pgdat
->node_id
;
225 nr_pages
= PAGE_ALIGN(sizeof(struct pglist_data
)) >> PAGE_SHIFT
;
226 page
= virt_to_page(pgdat
);
228 for (i
= 0; i
< nr_pages
; i
++, page
++)
229 get_page_bootmem(node
, page
, NODE_INFO
);
231 pfn
= pgdat
->node_start_pfn
;
232 end_pfn
= pgdat_end_pfn(pgdat
);
234 /* register section info */
235 for (; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
237 * Some platforms can assign the same pfn to multiple nodes - on
238 * node0 as well as nodeN. To avoid registering a pfn against
239 * multiple nodes we check that this pfn does not already
240 * reside in some other nodes.
242 if (pfn_valid(pfn
) && (early_pfn_to_nid(pfn
) == node
))
243 register_page_bootmem_info_section(pfn
);
246 #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */
248 static int __meminit
__add_section(int nid
, unsigned long phys_start_pfn
,
249 struct vmem_altmap
*altmap
, bool want_memblock
)
253 if (pfn_valid(phys_start_pfn
))
256 ret
= sparse_add_one_section(NODE_DATA(nid
), phys_start_pfn
, altmap
);
263 return hotplug_memory_register(nid
, __pfn_to_section(phys_start_pfn
));
267 * Reasonably generic function for adding memory. It is
268 * expected that archs that support memory hotplug will
269 * call this function after deciding the zone to which to
272 int __ref
__add_pages(int nid
, unsigned long phys_start_pfn
,
273 unsigned long nr_pages
, struct vmem_altmap
*altmap
,
278 int start_sec
, end_sec
;
280 /* during initialize mem_map, align hot-added range to section */
281 start_sec
= pfn_to_section_nr(phys_start_pfn
);
282 end_sec
= pfn_to_section_nr(phys_start_pfn
+ nr_pages
- 1);
286 * Validate altmap is within bounds of the total request
288 if (altmap
->base_pfn
!= phys_start_pfn
289 || vmem_altmap_offset(altmap
) > nr_pages
) {
290 pr_warn_once("memory add fail, invalid altmap\n");
297 for (i
= start_sec
; i
<= end_sec
; i
++) {
298 err
= __add_section(nid
, section_nr_to_pfn(i
), altmap
,
302 * EEXIST is finally dealt with by ioresource collision
303 * check. see add_memory() => register_memory_resource()
304 * Warning will be printed if there is collision.
306 if (err
&& (err
!= -EEXIST
))
311 vmemmap_populate_print_last();
316 #ifdef CONFIG_MEMORY_HOTREMOVE
317 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */
318 static unsigned long find_smallest_section_pfn(int nid
, struct zone
*zone
,
319 unsigned long start_pfn
,
320 unsigned long end_pfn
)
322 struct mem_section
*ms
;
324 for (; start_pfn
< end_pfn
; start_pfn
+= PAGES_PER_SECTION
) {
325 ms
= __pfn_to_section(start_pfn
);
327 if (unlikely(!valid_section(ms
)))
330 if (unlikely(pfn_to_nid(start_pfn
) != nid
))
333 if (zone
&& zone
!= page_zone(pfn_to_page(start_pfn
)))
342 /* find the biggest valid pfn in the range [start_pfn, end_pfn). */
343 static unsigned long find_biggest_section_pfn(int nid
, struct zone
*zone
,
344 unsigned long start_pfn
,
345 unsigned long end_pfn
)
347 struct mem_section
*ms
;
350 /* pfn is the end pfn of a memory section. */
352 for (; pfn
>= start_pfn
; pfn
-= PAGES_PER_SECTION
) {
353 ms
= __pfn_to_section(pfn
);
355 if (unlikely(!valid_section(ms
)))
358 if (unlikely(pfn_to_nid(pfn
) != nid
))
361 if (zone
&& zone
!= page_zone(pfn_to_page(pfn
)))
370 static void shrink_zone_span(struct zone
*zone
, unsigned long start_pfn
,
371 unsigned long end_pfn
)
373 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
374 unsigned long z
= zone_end_pfn(zone
); /* zone_end_pfn namespace clash */
375 unsigned long zone_end_pfn
= z
;
377 struct mem_section
*ms
;
378 int nid
= zone_to_nid(zone
);
380 zone_span_writelock(zone
);
381 if (zone_start_pfn
== start_pfn
) {
383 * If the section is smallest section in the zone, it need
384 * shrink zone->zone_start_pfn and zone->zone_spanned_pages.
385 * In this case, we find second smallest valid mem_section
386 * for shrinking zone.
388 pfn
= find_smallest_section_pfn(nid
, zone
, end_pfn
,
391 zone
->zone_start_pfn
= pfn
;
392 zone
->spanned_pages
= zone_end_pfn
- pfn
;
394 } else if (zone_end_pfn
== end_pfn
) {
396 * If the section is biggest section in the zone, it need
397 * shrink zone->spanned_pages.
398 * In this case, we find second biggest valid mem_section for
401 pfn
= find_biggest_section_pfn(nid
, zone
, zone_start_pfn
,
404 zone
->spanned_pages
= pfn
- zone_start_pfn
+ 1;
408 * The section is not biggest or smallest mem_section in the zone, it
409 * only creates a hole in the zone. So in this case, we need not
410 * change the zone. But perhaps, the zone has only hole data. Thus
411 * it check the zone has only hole or not.
413 pfn
= zone_start_pfn
;
414 for (; pfn
< zone_end_pfn
; pfn
+= PAGES_PER_SECTION
) {
415 ms
= __pfn_to_section(pfn
);
417 if (unlikely(!valid_section(ms
)))
420 if (page_zone(pfn_to_page(pfn
)) != zone
)
423 /* If the section is current section, it continues the loop */
424 if (start_pfn
== pfn
)
427 /* If we find valid section, we have nothing to do */
428 zone_span_writeunlock(zone
);
432 /* The zone has no valid section */
433 zone
->zone_start_pfn
= 0;
434 zone
->spanned_pages
= 0;
435 zone_span_writeunlock(zone
);
438 static void shrink_pgdat_span(struct pglist_data
*pgdat
,
439 unsigned long start_pfn
, unsigned long end_pfn
)
441 unsigned long pgdat_start_pfn
= pgdat
->node_start_pfn
;
442 unsigned long p
= pgdat_end_pfn(pgdat
); /* pgdat_end_pfn namespace clash */
443 unsigned long pgdat_end_pfn
= p
;
445 struct mem_section
*ms
;
446 int nid
= pgdat
->node_id
;
448 if (pgdat_start_pfn
== start_pfn
) {
450 * If the section is smallest section in the pgdat, it need
451 * shrink pgdat->node_start_pfn and pgdat->node_spanned_pages.
452 * In this case, we find second smallest valid mem_section
453 * for shrinking zone.
455 pfn
= find_smallest_section_pfn(nid
, NULL
, end_pfn
,
458 pgdat
->node_start_pfn
= pfn
;
459 pgdat
->node_spanned_pages
= pgdat_end_pfn
- pfn
;
461 } else if (pgdat_end_pfn
== end_pfn
) {
463 * If the section is biggest section in the pgdat, it need
464 * shrink pgdat->node_spanned_pages.
465 * In this case, we find second biggest valid mem_section for
468 pfn
= find_biggest_section_pfn(nid
, NULL
, pgdat_start_pfn
,
471 pgdat
->node_spanned_pages
= pfn
- pgdat_start_pfn
+ 1;
475 * If the section is not biggest or smallest mem_section in the pgdat,
476 * it only creates a hole in the pgdat. So in this case, we need not
478 * But perhaps, the pgdat has only hole data. Thus it check the pgdat
479 * has only hole or not.
481 pfn
= pgdat_start_pfn
;
482 for (; pfn
< pgdat_end_pfn
; pfn
+= PAGES_PER_SECTION
) {
483 ms
= __pfn_to_section(pfn
);
485 if (unlikely(!valid_section(ms
)))
488 if (pfn_to_nid(pfn
) != nid
)
491 /* If the section is current section, it continues the loop */
492 if (start_pfn
== pfn
)
495 /* If we find valid section, we have nothing to do */
499 /* The pgdat has no valid section */
500 pgdat
->node_start_pfn
= 0;
501 pgdat
->node_spanned_pages
= 0;
504 static void __remove_zone(struct zone
*zone
, unsigned long start_pfn
)
506 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
507 int nr_pages
= PAGES_PER_SECTION
;
510 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
511 shrink_zone_span(zone
, start_pfn
, start_pfn
+ nr_pages
);
512 shrink_pgdat_span(pgdat
, start_pfn
, start_pfn
+ nr_pages
);
513 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
516 static int __remove_section(struct zone
*zone
, struct mem_section
*ms
,
517 unsigned long map_offset
, struct vmem_altmap
*altmap
)
519 unsigned long start_pfn
;
523 if (!valid_section(ms
))
526 ret
= unregister_memory_section(ms
);
530 scn_nr
= __section_nr(ms
);
531 start_pfn
= section_nr_to_pfn((unsigned long)scn_nr
);
532 __remove_zone(zone
, start_pfn
);
534 sparse_remove_one_section(zone
, ms
, map_offset
, altmap
);
539 * __remove_pages() - remove sections of pages from a zone
540 * @zone: zone from which pages need to be removed
541 * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
542 * @nr_pages: number of pages to remove (must be multiple of section size)
543 * @altmap: alternative device page map or %NULL if default memmap is used
545 * Generic helper function to remove section mappings and sysfs entries
546 * for the section of the memory we are removing. Caller needs to make
547 * sure that pages are marked reserved and zones are adjust properly by
548 * calling offline_pages().
550 int __remove_pages(struct zone
*zone
, unsigned long phys_start_pfn
,
551 unsigned long nr_pages
, struct vmem_altmap
*altmap
)
554 unsigned long map_offset
= 0;
555 int sections_to_remove
, ret
= 0;
557 /* In the ZONE_DEVICE case device driver owns the memory region */
558 if (is_dev_zone(zone
)) {
560 map_offset
= vmem_altmap_offset(altmap
);
562 resource_size_t start
, size
;
564 start
= phys_start_pfn
<< PAGE_SHIFT
;
565 size
= nr_pages
* PAGE_SIZE
;
567 ret
= release_mem_region_adjustable(&iomem_resource
, start
,
570 resource_size_t endres
= start
+ size
- 1;
572 pr_warn("Unable to release resource <%pa-%pa> (%d)\n",
573 &start
, &endres
, ret
);
577 clear_zone_contiguous(zone
);
580 * We can only remove entire sections
582 BUG_ON(phys_start_pfn
& ~PAGE_SECTION_MASK
);
583 BUG_ON(nr_pages
% PAGES_PER_SECTION
);
585 sections_to_remove
= nr_pages
/ PAGES_PER_SECTION
;
586 for (i
= 0; i
< sections_to_remove
; i
++) {
587 unsigned long pfn
= phys_start_pfn
+ i
*PAGES_PER_SECTION
;
589 ret
= __remove_section(zone
, __pfn_to_section(pfn
), map_offset
,
596 set_zone_contiguous(zone
);
600 #endif /* CONFIG_MEMORY_HOTREMOVE */
602 int set_online_page_callback(online_page_callback_t callback
)
607 mutex_lock(&online_page_callback_lock
);
609 if (online_page_callback
== generic_online_page
) {
610 online_page_callback
= callback
;
614 mutex_unlock(&online_page_callback_lock
);
619 EXPORT_SYMBOL_GPL(set_online_page_callback
);
621 int restore_online_page_callback(online_page_callback_t callback
)
626 mutex_lock(&online_page_callback_lock
);
628 if (online_page_callback
== callback
) {
629 online_page_callback
= generic_online_page
;
633 mutex_unlock(&online_page_callback_lock
);
638 EXPORT_SYMBOL_GPL(restore_online_page_callback
);
640 void __online_page_set_limits(struct page
*page
)
643 EXPORT_SYMBOL_GPL(__online_page_set_limits
);
645 void __online_page_increment_counters(struct page
*page
)
647 adjust_managed_page_count(page
, 1);
649 EXPORT_SYMBOL_GPL(__online_page_increment_counters
);
651 void __online_page_free(struct page
*page
)
653 __free_reserved_page(page
);
655 EXPORT_SYMBOL_GPL(__online_page_free
);
657 static void generic_online_page(struct page
*page
)
659 __online_page_set_limits(page
);
660 __online_page_increment_counters(page
);
661 __online_page_free(page
);
664 static int online_pages_range(unsigned long start_pfn
, unsigned long nr_pages
,
668 unsigned long onlined_pages
= *(unsigned long *)arg
;
671 if (PageReserved(pfn_to_page(start_pfn
)))
672 for (i
= 0; i
< nr_pages
; i
++) {
673 page
= pfn_to_page(start_pfn
+ i
);
674 (*online_page_callback
)(page
);
678 online_mem_sections(start_pfn
, start_pfn
+ nr_pages
);
680 *(unsigned long *)arg
= onlined_pages
;
684 /* check which state of node_states will be changed when online memory */
685 static void node_states_check_changes_online(unsigned long nr_pages
,
686 struct zone
*zone
, struct memory_notify
*arg
)
688 int nid
= zone_to_nid(zone
);
690 arg
->status_change_nid
= -1;
691 arg
->status_change_nid_normal
= -1;
692 arg
->status_change_nid_high
= -1;
694 if (!node_state(nid
, N_MEMORY
))
695 arg
->status_change_nid
= nid
;
696 if (zone_idx(zone
) <= ZONE_NORMAL
&& !node_state(nid
, N_NORMAL_MEMORY
))
697 arg
->status_change_nid_normal
= nid
;
698 #ifdef CONFIG_HIGHMEM
699 if (zone_idx(zone
) <= N_HIGH_MEMORY
&& !node_state(nid
, N_HIGH_MEMORY
))
700 arg
->status_change_nid_high
= nid
;
704 static void node_states_set_node(int node
, struct memory_notify
*arg
)
706 if (arg
->status_change_nid_normal
>= 0)
707 node_set_state(node
, N_NORMAL_MEMORY
);
709 if (arg
->status_change_nid_high
>= 0)
710 node_set_state(node
, N_HIGH_MEMORY
);
712 if (arg
->status_change_nid
>= 0)
713 node_set_state(node
, N_MEMORY
);
716 static void __meminit
resize_zone_range(struct zone
*zone
, unsigned long start_pfn
,
717 unsigned long nr_pages
)
719 unsigned long old_end_pfn
= zone_end_pfn(zone
);
721 if (zone_is_empty(zone
) || start_pfn
< zone
->zone_start_pfn
)
722 zone
->zone_start_pfn
= start_pfn
;
724 zone
->spanned_pages
= max(start_pfn
+ nr_pages
, old_end_pfn
) - zone
->zone_start_pfn
;
727 static void __meminit
resize_pgdat_range(struct pglist_data
*pgdat
, unsigned long start_pfn
,
728 unsigned long nr_pages
)
730 unsigned long old_end_pfn
= pgdat_end_pfn(pgdat
);
732 if (!pgdat
->node_spanned_pages
|| start_pfn
< pgdat
->node_start_pfn
)
733 pgdat
->node_start_pfn
= start_pfn
;
735 pgdat
->node_spanned_pages
= max(start_pfn
+ nr_pages
, old_end_pfn
) - pgdat
->node_start_pfn
;
738 void __ref
move_pfn_range_to_zone(struct zone
*zone
, unsigned long start_pfn
,
739 unsigned long nr_pages
, struct vmem_altmap
*altmap
)
741 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
742 int nid
= pgdat
->node_id
;
745 if (zone_is_empty(zone
))
746 init_currently_empty_zone(zone
, start_pfn
, nr_pages
);
748 clear_zone_contiguous(zone
);
750 /* TODO Huh pgdat is irqsave while zone is not. It used to be like that before */
751 pgdat_resize_lock(pgdat
, &flags
);
752 zone_span_writelock(zone
);
753 resize_zone_range(zone
, start_pfn
, nr_pages
);
754 zone_span_writeunlock(zone
);
755 resize_pgdat_range(pgdat
, start_pfn
, nr_pages
);
756 pgdat_resize_unlock(pgdat
, &flags
);
759 * TODO now we have a visible range of pages which are not associated
760 * with their zone properly. Not nice but set_pfnblock_flags_mask
761 * expects the zone spans the pfn range. All the pages in the range
762 * are reserved so nobody should be touching them so we should be safe
764 memmap_init_zone(nr_pages
, nid
, zone_idx(zone
), start_pfn
,
765 MEMMAP_HOTPLUG
, altmap
);
767 set_zone_contiguous(zone
);
771 * Returns a default kernel memory zone for the given pfn range.
772 * If no kernel zone covers this pfn range it will automatically go
773 * to the ZONE_NORMAL.
775 static struct zone
*default_kernel_zone_for_pfn(int nid
, unsigned long start_pfn
,
776 unsigned long nr_pages
)
778 struct pglist_data
*pgdat
= NODE_DATA(nid
);
781 for (zid
= 0; zid
<= ZONE_NORMAL
; zid
++) {
782 struct zone
*zone
= &pgdat
->node_zones
[zid
];
784 if (zone_intersects(zone
, start_pfn
, nr_pages
))
788 return &pgdat
->node_zones
[ZONE_NORMAL
];
791 static inline struct zone
*default_zone_for_pfn(int nid
, unsigned long start_pfn
,
792 unsigned long nr_pages
)
794 struct zone
*kernel_zone
= default_kernel_zone_for_pfn(nid
, start_pfn
,
796 struct zone
*movable_zone
= &NODE_DATA(nid
)->node_zones
[ZONE_MOVABLE
];
797 bool in_kernel
= zone_intersects(kernel_zone
, start_pfn
, nr_pages
);
798 bool in_movable
= zone_intersects(movable_zone
, start_pfn
, nr_pages
);
801 * We inherit the existing zone in a simple case where zones do not
802 * overlap in the given range
804 if (in_kernel
^ in_movable
)
805 return (in_kernel
) ? kernel_zone
: movable_zone
;
808 * If the range doesn't belong to any zone or two zones overlap in the
809 * given range then we use movable zone only if movable_node is
810 * enabled because we always online to a kernel zone by default.
812 return movable_node_enabled
? movable_zone
: kernel_zone
;
815 struct zone
* zone_for_pfn_range(int online_type
, int nid
, unsigned start_pfn
,
816 unsigned long nr_pages
)
818 if (online_type
== MMOP_ONLINE_KERNEL
)
819 return default_kernel_zone_for_pfn(nid
, start_pfn
, nr_pages
);
821 if (online_type
== MMOP_ONLINE_MOVABLE
)
822 return &NODE_DATA(nid
)->node_zones
[ZONE_MOVABLE
];
824 return default_zone_for_pfn(nid
, start_pfn
, nr_pages
);
828 * Associates the given pfn range with the given node and the zone appropriate
829 * for the given online type.
831 static struct zone
* __meminit
move_pfn_range(int online_type
, int nid
,
832 unsigned long start_pfn
, unsigned long nr_pages
)
836 zone
= zone_for_pfn_range(online_type
, nid
, start_pfn
, nr_pages
);
837 move_pfn_range_to_zone(zone
, start_pfn
, nr_pages
, NULL
);
841 /* Must be protected by mem_hotplug_begin() or a device_lock */
842 int __ref
online_pages(unsigned long pfn
, unsigned long nr_pages
, int online_type
)
845 unsigned long onlined_pages
= 0;
847 int need_zonelists_rebuild
= 0;
850 struct memory_notify arg
;
851 struct memory_block
*mem
;
854 * We can't use pfn_to_nid() because nid might be stored in struct page
855 * which is not yet initialized. Instead, we find nid from memory block.
857 mem
= find_memory_block(__pfn_to_section(pfn
));
860 /* associate pfn range with the zone */
861 zone
= move_pfn_range(online_type
, nid
, pfn
, nr_pages
);
864 arg
.nr_pages
= nr_pages
;
865 node_states_check_changes_online(nr_pages
, zone
, &arg
);
867 ret
= memory_notify(MEM_GOING_ONLINE
, &arg
);
868 ret
= notifier_to_errno(ret
);
870 goto failed_addition
;
873 * If this zone is not populated, then it is not in zonelist.
874 * This means the page allocator ignores this zone.
875 * So, zonelist must be updated after online.
877 if (!populated_zone(zone
)) {
878 need_zonelists_rebuild
= 1;
879 setup_zone_pageset(zone
);
882 ret
= walk_system_ram_range(pfn
, nr_pages
, &onlined_pages
,
885 if (need_zonelists_rebuild
)
886 zone_pcp_reset(zone
);
887 goto failed_addition
;
890 zone
->present_pages
+= onlined_pages
;
892 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
893 zone
->zone_pgdat
->node_present_pages
+= onlined_pages
;
894 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
897 node_states_set_node(nid
, &arg
);
898 if (need_zonelists_rebuild
)
899 build_all_zonelists(NULL
);
901 zone_pcp_update(zone
);
904 init_per_zone_wmark_min();
911 vm_total_pages
= nr_free_pagecache_pages();
913 writeback_set_ratelimit();
916 memory_notify(MEM_ONLINE
, &arg
);
920 pr_debug("online_pages [mem %#010llx-%#010llx] failed\n",
921 (unsigned long long) pfn
<< PAGE_SHIFT
,
922 (((unsigned long long) pfn
+ nr_pages
) << PAGE_SHIFT
) - 1);
923 memory_notify(MEM_CANCEL_ONLINE
, &arg
);
926 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
928 static void reset_node_present_pages(pg_data_t
*pgdat
)
932 for (z
= pgdat
->node_zones
; z
< pgdat
->node_zones
+ MAX_NR_ZONES
; z
++)
933 z
->present_pages
= 0;
935 pgdat
->node_present_pages
= 0;
938 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
939 static pg_data_t __ref
*hotadd_new_pgdat(int nid
, u64 start
)
941 struct pglist_data
*pgdat
;
942 unsigned long start_pfn
= PFN_DOWN(start
);
944 pgdat
= NODE_DATA(nid
);
946 pgdat
= arch_alloc_nodedata(nid
);
950 arch_refresh_nodedata(nid
, pgdat
);
953 * Reset the nr_zones, order and classzone_idx before reuse.
954 * Note that kswapd will init kswapd_classzone_idx properly
955 * when it starts in the near future.
958 pgdat
->kswapd_order
= 0;
959 pgdat
->kswapd_classzone_idx
= 0;
962 /* we can use NODE_DATA(nid) from here */
964 pgdat
->node_id
= nid
;
965 pgdat
->node_start_pfn
= start_pfn
;
967 /* init node's zones as empty zones, we don't have any present pages.*/
968 free_area_init_core_hotplug(nid
);
969 pgdat
->per_cpu_nodestats
= alloc_percpu(struct per_cpu_nodestat
);
972 * The node we allocated has no zone fallback lists. For avoiding
973 * to access not-initialized zonelist, build here.
975 build_all_zonelists(pgdat
);
978 * When memory is hot-added, all the memory is in offline state. So
979 * clear all zones' present_pages because they will be updated in
980 * online_pages() and offline_pages().
982 reset_node_managed_pages(pgdat
);
983 reset_node_present_pages(pgdat
);
988 static void rollback_node_hotadd(int nid
)
990 pg_data_t
*pgdat
= NODE_DATA(nid
);
992 arch_refresh_nodedata(nid
, NULL
);
993 free_percpu(pgdat
->per_cpu_nodestats
);
994 arch_free_nodedata(pgdat
);
1000 * try_online_node - online a node if offlined
1002 * @start: start addr of the node
1003 * @set_node_online: Whether we want to online the node
1004 * called by cpu_up() to online a node without onlined memory.
1007 * 1 -> a new node has been allocated
1008 * 0 -> the node is already online
1009 * -ENOMEM -> the node could not be allocated
1011 static int __try_online_node(int nid
, u64 start
, bool set_node_online
)
1016 if (node_online(nid
))
1019 pgdat
= hotadd_new_pgdat(nid
, start
);
1021 pr_err("Cannot online node %d due to NULL pgdat\n", nid
);
1026 if (set_node_online
) {
1027 node_set_online(nid
);
1028 ret
= register_one_node(nid
);
1036 * Users of this function always want to online/register the node
1038 int try_online_node(int nid
)
1042 mem_hotplug_begin();
1043 ret
= __try_online_node(nid
, 0, true);
1048 static int check_hotplug_memory_range(u64 start
, u64 size
)
1050 unsigned long block_sz
= memory_block_size_bytes();
1051 u64 block_nr_pages
= block_sz
>> PAGE_SHIFT
;
1052 u64 nr_pages
= size
>> PAGE_SHIFT
;
1053 u64 start_pfn
= PFN_DOWN(start
);
1055 /* memory range must be block size aligned */
1056 if (!nr_pages
|| !IS_ALIGNED(start_pfn
, block_nr_pages
) ||
1057 !IS_ALIGNED(nr_pages
, block_nr_pages
)) {
1058 pr_err("Block size [%#lx] unaligned hotplug range: start %#llx, size %#llx",
1059 block_sz
, start
, size
);
1066 static int online_memory_block(struct memory_block
*mem
, void *arg
)
1068 return device_online(&mem
->dev
);
1071 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
1072 int __ref
add_memory_resource(int nid
, struct resource
*res
, bool online
)
1075 bool new_node
= false;
1079 size
= resource_size(res
);
1081 ret
= check_hotplug_memory_range(start
, size
);
1085 mem_hotplug_begin();
1088 * Add new range to memblock so that when hotadd_new_pgdat() is called
1089 * to allocate new pgdat, get_pfn_range_for_nid() will be able to find
1090 * this new range and calculate total pages correctly. The range will
1091 * be removed at hot-remove time.
1093 memblock_add_node(start
, size
, nid
);
1095 ret
= __try_online_node(nid
, start
, false);
1100 /* call arch's memory hotadd */
1101 ret
= arch_add_memory(nid
, start
, size
, NULL
, true);
1106 /* If sysfs file of new node can't be created, cpu on the node
1107 * can't be hot-added. There is no rollback way now.
1108 * So, check by BUG_ON() to catch it reluctantly..
1109 * We online node here. We can't roll back from here.
1111 node_set_online(nid
);
1112 ret
= __register_one_node(nid
);
1116 /* link memory sections under this node.*/
1117 ret
= link_mem_sections(nid
, PFN_DOWN(start
), PFN_UP(start
+ size
- 1));
1120 /* create new memmap entry */
1121 firmware_map_add_hotplug(start
, start
+ size
, "System RAM");
1123 /* online pages if requested */
1125 walk_memory_range(PFN_DOWN(start
), PFN_UP(start
+ size
- 1),
1126 NULL
, online_memory_block
);
1131 /* rollback pgdat allocation and others */
1133 rollback_node_hotadd(nid
);
1134 memblock_remove(start
, size
);
1140 EXPORT_SYMBOL_GPL(add_memory_resource
);
1142 int __ref
add_memory(int nid
, u64 start
, u64 size
)
1144 struct resource
*res
;
1147 res
= register_memory_resource(start
, size
);
1149 return PTR_ERR(res
);
1151 ret
= add_memory_resource(nid
, res
, memhp_auto_online
);
1153 release_memory_resource(res
);
1156 EXPORT_SYMBOL_GPL(add_memory
);
1158 #ifdef CONFIG_MEMORY_HOTREMOVE
1160 * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
1161 * set and the size of the free page is given by page_order(). Using this,
1162 * the function determines if the pageblock contains only free pages.
1163 * Due to buddy contraints, a free page at least the size of a pageblock will
1164 * be located at the start of the pageblock
1166 static inline int pageblock_free(struct page
*page
)
1168 return PageBuddy(page
) && page_order(page
) >= pageblock_order
;
1171 /* Return the start of the next active pageblock after a given page */
1172 static struct page
*next_active_pageblock(struct page
*page
)
1174 /* Ensure the starting page is pageblock-aligned */
1175 BUG_ON(page_to_pfn(page
) & (pageblock_nr_pages
- 1));
1177 /* If the entire pageblock is free, move to the end of free page */
1178 if (pageblock_free(page
)) {
1180 /* be careful. we don't have locks, page_order can be changed.*/
1181 order
= page_order(page
);
1182 if ((order
< MAX_ORDER
) && (order
>= pageblock_order
))
1183 return page
+ (1 << order
);
1186 return page
+ pageblock_nr_pages
;
1189 static bool is_pageblock_removable_nolock(struct page
*page
)
1195 * We have to be careful here because we are iterating over memory
1196 * sections which are not zone aware so we might end up outside of
1197 * the zone but still within the section.
1198 * We have to take care about the node as well. If the node is offline
1199 * its NODE_DATA will be NULL - see page_zone.
1201 if (!node_online(page_to_nid(page
)))
1204 zone
= page_zone(page
);
1205 pfn
= page_to_pfn(page
);
1206 if (!zone_spans_pfn(zone
, pfn
))
1209 return !has_unmovable_pages(zone
, page
, 0, MIGRATE_MOVABLE
, true);
1212 /* Checks if this range of memory is likely to be hot-removable. */
1213 bool is_mem_section_removable(unsigned long start_pfn
, unsigned long nr_pages
)
1215 struct page
*page
= pfn_to_page(start_pfn
);
1216 struct page
*end_page
= page
+ nr_pages
;
1218 /* Check the starting page of each pageblock within the range */
1219 for (; page
< end_page
; page
= next_active_pageblock(page
)) {
1220 if (!is_pageblock_removable_nolock(page
))
1225 /* All pageblocks in the memory block are likely to be hot-removable */
1230 * Confirm all pages in a range [start, end) belong to the same zone.
1231 * When true, return its valid [start, end).
1233 int test_pages_in_a_zone(unsigned long start_pfn
, unsigned long end_pfn
,
1234 unsigned long *valid_start
, unsigned long *valid_end
)
1236 unsigned long pfn
, sec_end_pfn
;
1237 unsigned long start
, end
;
1238 struct zone
*zone
= NULL
;
1241 for (pfn
= start_pfn
, sec_end_pfn
= SECTION_ALIGN_UP(start_pfn
+ 1);
1243 pfn
= sec_end_pfn
, sec_end_pfn
+= PAGES_PER_SECTION
) {
1244 /* Make sure the memory section is present first */
1245 if (!present_section_nr(pfn_to_section_nr(pfn
)))
1247 for (; pfn
< sec_end_pfn
&& pfn
< end_pfn
;
1248 pfn
+= MAX_ORDER_NR_PAGES
) {
1250 /* This is just a CONFIG_HOLES_IN_ZONE check.*/
1251 while ((i
< MAX_ORDER_NR_PAGES
) &&
1252 !pfn_valid_within(pfn
+ i
))
1254 if (i
== MAX_ORDER_NR_PAGES
|| pfn
+ i
>= end_pfn
)
1256 page
= pfn_to_page(pfn
+ i
);
1257 if (zone
&& page_zone(page
) != zone
)
1261 zone
= page_zone(page
);
1262 end
= pfn
+ MAX_ORDER_NR_PAGES
;
1267 *valid_start
= start
;
1268 *valid_end
= min(end
, end_pfn
);
1276 * Scan pfn range [start,end) to find movable/migratable pages (LRU pages,
1277 * non-lru movable pages and hugepages). We scan pfn because it's much
1278 * easier than scanning over linked list. This function returns the pfn
1279 * of the first found movable page if it's found, otherwise 0.
1281 static unsigned long scan_movable_pages(unsigned long start
, unsigned long end
)
1285 for (pfn
= start
; pfn
< end
; pfn
++) {
1286 if (pfn_valid(pfn
)) {
1287 page
= pfn_to_page(pfn
);
1290 if (__PageMovable(page
))
1292 if (PageHuge(page
)) {
1293 if (hugepage_migration_supported(page_hstate(page
)) &&
1294 page_huge_active(page
))
1297 pfn
= round_up(pfn
+ 1,
1298 1 << compound_order(page
)) - 1;
1305 static struct page
*new_node_page(struct page
*page
, unsigned long private)
1307 int nid
= page_to_nid(page
);
1308 nodemask_t nmask
= node_states
[N_MEMORY
];
1311 * try to allocate from a different node but reuse this node if there
1312 * are no other online nodes to be used (e.g. we are offlining a part
1313 * of the only existing node)
1315 node_clear(nid
, nmask
);
1316 if (nodes_empty(nmask
))
1317 node_set(nid
, nmask
);
1319 return new_page_nodemask(page
, nid
, &nmask
);
1322 #define NR_OFFLINE_AT_ONCE_PAGES (256)
1324 do_migrate_range(unsigned long start_pfn
, unsigned long end_pfn
)
1328 int move_pages
= NR_OFFLINE_AT_ONCE_PAGES
;
1329 int not_managed
= 0;
1333 for (pfn
= start_pfn
; pfn
< end_pfn
&& move_pages
> 0; pfn
++) {
1334 if (!pfn_valid(pfn
))
1336 page
= pfn_to_page(pfn
);
1338 if (PageHuge(page
)) {
1339 struct page
*head
= compound_head(page
);
1340 pfn
= page_to_pfn(head
) + (1<<compound_order(head
)) - 1;
1341 if (compound_order(head
) > PFN_SECTION_SHIFT
) {
1345 if (isolate_huge_page(page
, &source
))
1346 move_pages
-= 1 << compound_order(head
);
1348 } else if (PageTransHuge(page
))
1349 pfn
= page_to_pfn(compound_head(page
))
1350 + hpage_nr_pages(page
) - 1;
1352 if (!get_page_unless_zero(page
))
1355 * We can skip free pages. And we can deal with pages on
1356 * LRU and non-lru movable pages.
1359 ret
= isolate_lru_page(page
);
1361 ret
= isolate_movable_page(page
, ISOLATE_UNEVICTABLE
);
1362 if (!ret
) { /* Success */
1364 list_add_tail(&page
->lru
, &source
);
1366 if (!__PageMovable(page
))
1367 inc_node_page_state(page
, NR_ISOLATED_ANON
+
1368 page_is_file_cache(page
));
1371 #ifdef CONFIG_DEBUG_VM
1372 pr_alert("failed to isolate pfn %lx\n", pfn
);
1373 dump_page(page
, "isolation failed");
1376 /* Because we don't have big zone->lock. we should
1377 check this again here. */
1378 if (page_count(page
)) {
1385 if (!list_empty(&source
)) {
1387 putback_movable_pages(&source
);
1391 /* Allocate a new page from the nearest neighbor node */
1392 ret
= migrate_pages(&source
, new_node_page
, NULL
, 0,
1393 MIGRATE_SYNC
, MR_MEMORY_HOTPLUG
);
1395 putback_movable_pages(&source
);
1402 * remove from free_area[] and mark all as Reserved.
1405 offline_isolated_pages_cb(unsigned long start
, unsigned long nr_pages
,
1408 __offline_isolated_pages(start
, start
+ nr_pages
);
1413 offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
1415 walk_system_ram_range(start_pfn
, end_pfn
- start_pfn
, NULL
,
1416 offline_isolated_pages_cb
);
1420 * Check all pages in range, recoreded as memory resource, are isolated.
1423 check_pages_isolated_cb(unsigned long start_pfn
, unsigned long nr_pages
,
1427 long offlined
= *(long *)data
;
1428 ret
= test_pages_isolated(start_pfn
, start_pfn
+ nr_pages
, true);
1429 offlined
= nr_pages
;
1431 *(long *)data
+= offlined
;
1436 check_pages_isolated(unsigned long start_pfn
, unsigned long end_pfn
)
1441 ret
= walk_system_ram_range(start_pfn
, end_pfn
- start_pfn
, &offlined
,
1442 check_pages_isolated_cb
);
1444 offlined
= (long)ret
;
1448 static int __init
cmdline_parse_movable_node(char *p
)
1450 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
1451 movable_node_enabled
= true;
1453 pr_warn("movable_node parameter depends on CONFIG_HAVE_MEMBLOCK_NODE_MAP to work properly\n");
1457 early_param("movable_node", cmdline_parse_movable_node
);
1459 /* check which state of node_states will be changed when offline memory */
1460 static void node_states_check_changes_offline(unsigned long nr_pages
,
1461 struct zone
*zone
, struct memory_notify
*arg
)
1463 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
1464 unsigned long present_pages
= 0;
1467 arg
->status_change_nid
= -1;
1468 arg
->status_change_nid_normal
= -1;
1469 arg
->status_change_nid_high
= -1;
1472 * Check whether node_states[N_NORMAL_MEMORY] will be changed.
1473 * If the memory to be offline is within the range
1474 * [0..ZONE_NORMAL], and it is the last present memory there,
1475 * the zones in that range will become empty after the offlining,
1476 * thus we can determine that we need to clear the node from
1477 * node_states[N_NORMAL_MEMORY].
1479 for (zt
= 0; zt
<= ZONE_NORMAL
; zt
++)
1480 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1481 if (zone_idx(zone
) <= ZONE_NORMAL
&& nr_pages
>= present_pages
)
1482 arg
->status_change_nid_normal
= zone_to_nid(zone
);
1484 #ifdef CONFIG_HIGHMEM
1486 * node_states[N_HIGH_MEMORY] contains nodes which
1487 * have normal memory or high memory.
1488 * Here we add the present_pages belonging to ZONE_HIGHMEM.
1489 * If the zone is within the range of [0..ZONE_HIGHMEM), and
1490 * we determine that the zones in that range become empty,
1491 * we need to clear the node for N_HIGH_MEMORY.
1493 present_pages
+= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
1494 if (zone_idx(zone
) <= ZONE_HIGHMEM
&& nr_pages
>= present_pages
)
1495 arg
->status_change_nid_high
= zone_to_nid(zone
);
1499 * We have accounted the pages from [0..ZONE_NORMAL), and
1500 * in case of CONFIG_HIGHMEM the pages from ZONE_HIGHMEM
1502 * Here we count the possible pages from ZONE_MOVABLE.
1503 * If after having accounted all the pages, we see that the nr_pages
1504 * to be offlined is over or equal to the accounted pages,
1505 * we know that the node will become empty, and so, we can clear
1506 * it for N_MEMORY as well.
1508 present_pages
+= pgdat
->node_zones
[ZONE_MOVABLE
].present_pages
;
1510 if (nr_pages
>= present_pages
)
1511 arg
->status_change_nid
= zone_to_nid(zone
);
1514 static void node_states_clear_node(int node
, struct memory_notify
*arg
)
1516 if (arg
->status_change_nid_normal
>= 0)
1517 node_clear_state(node
, N_NORMAL_MEMORY
);
1519 if (arg
->status_change_nid_high
>= 0)
1520 node_clear_state(node
, N_HIGH_MEMORY
);
1522 if (arg
->status_change_nid
>= 0)
1523 node_clear_state(node
, N_MEMORY
);
1526 static int __ref
__offline_pages(unsigned long start_pfn
,
1527 unsigned long end_pfn
)
1529 unsigned long pfn
, nr_pages
;
1530 long offlined_pages
;
1532 unsigned long flags
;
1533 unsigned long valid_start
, valid_end
;
1535 struct memory_notify arg
;
1537 /* at least, alignment against pageblock is necessary */
1538 if (!IS_ALIGNED(start_pfn
, pageblock_nr_pages
))
1540 if (!IS_ALIGNED(end_pfn
, pageblock_nr_pages
))
1542 /* This makes hotplug much easier...and readable.
1543 we assume this for now. .*/
1544 if (!test_pages_in_a_zone(start_pfn
, end_pfn
, &valid_start
, &valid_end
))
1547 zone
= page_zone(pfn_to_page(valid_start
));
1548 node
= zone_to_nid(zone
);
1549 nr_pages
= end_pfn
- start_pfn
;
1551 /* set above range as isolated */
1552 ret
= start_isolate_page_range(start_pfn
, end_pfn
,
1553 MIGRATE_MOVABLE
, true);
1557 arg
.start_pfn
= start_pfn
;
1558 arg
.nr_pages
= nr_pages
;
1559 node_states_check_changes_offline(nr_pages
, zone
, &arg
);
1561 ret
= memory_notify(MEM_GOING_OFFLINE
, &arg
);
1562 ret
= notifier_to_errno(ret
);
1564 goto failed_removal
;
1568 /* start memory hot removal */
1570 if (signal_pending(current
))
1571 goto failed_removal
;
1574 lru_add_drain_all();
1575 drain_all_pages(zone
);
1577 pfn
= scan_movable_pages(start_pfn
, end_pfn
);
1578 if (pfn
) { /* We have movable pages */
1579 ret
= do_migrate_range(pfn
, end_pfn
);
1584 * dissolve free hugepages in the memory block before doing offlining
1585 * actually in order to make hugetlbfs's object counting consistent.
1587 ret
= dissolve_free_huge_pages(start_pfn
, end_pfn
);
1589 goto failed_removal
;
1591 offlined_pages
= check_pages_isolated(start_pfn
, end_pfn
);
1592 if (offlined_pages
< 0)
1594 pr_info("Offlined Pages %ld\n", offlined_pages
);
1595 /* Ok, all of our target is isolated.
1596 We cannot do rollback at this point. */
1597 offline_isolated_pages(start_pfn
, end_pfn
);
1598 /* reset pagetype flags and makes migrate type to be MOVABLE */
1599 undo_isolate_page_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
);
1600 /* removal success */
1601 adjust_managed_page_count(pfn_to_page(start_pfn
), -offlined_pages
);
1602 zone
->present_pages
-= offlined_pages
;
1604 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
1605 zone
->zone_pgdat
->node_present_pages
-= offlined_pages
;
1606 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
1608 init_per_zone_wmark_min();
1610 if (!populated_zone(zone
)) {
1611 zone_pcp_reset(zone
);
1612 build_all_zonelists(NULL
);
1614 zone_pcp_update(zone
);
1616 node_states_clear_node(node
, &arg
);
1617 if (arg
.status_change_nid
>= 0) {
1619 kcompactd_stop(node
);
1622 vm_total_pages
= nr_free_pagecache_pages();
1623 writeback_set_ratelimit();
1625 memory_notify(MEM_OFFLINE
, &arg
);
1629 pr_debug("memory offlining [mem %#010llx-%#010llx] failed\n",
1630 (unsigned long long) start_pfn
<< PAGE_SHIFT
,
1631 ((unsigned long long) end_pfn
<< PAGE_SHIFT
) - 1);
1632 memory_notify(MEM_CANCEL_OFFLINE
, &arg
);
1633 /* pushback to free area */
1634 undo_isolate_page_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
);
1638 /* Must be protected by mem_hotplug_begin() or a device_lock */
1639 int offline_pages(unsigned long start_pfn
, unsigned long nr_pages
)
1641 return __offline_pages(start_pfn
, start_pfn
+ nr_pages
);
1643 #endif /* CONFIG_MEMORY_HOTREMOVE */
1646 * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn)
1647 * @start_pfn: start pfn of the memory range
1648 * @end_pfn: end pfn of the memory range
1649 * @arg: argument passed to func
1650 * @func: callback for each memory section walked
1652 * This function walks through all present mem sections in range
1653 * [start_pfn, end_pfn) and call func on each mem section.
1655 * Returns the return value of func.
1657 int walk_memory_range(unsigned long start_pfn
, unsigned long end_pfn
,
1658 void *arg
, int (*func
)(struct memory_block
*, void *))
1660 struct memory_block
*mem
= NULL
;
1661 struct mem_section
*section
;
1662 unsigned long pfn
, section_nr
;
1665 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
1666 section_nr
= pfn_to_section_nr(pfn
);
1667 if (!present_section_nr(section_nr
))
1670 section
= __nr_to_section(section_nr
);
1671 /* same memblock? */
1673 if ((section_nr
>= mem
->start_section_nr
) &&
1674 (section_nr
<= mem
->end_section_nr
))
1677 mem
= find_memory_block_hinted(section
, mem
);
1681 ret
= func(mem
, arg
);
1683 kobject_put(&mem
->dev
.kobj
);
1689 kobject_put(&mem
->dev
.kobj
);
1694 #ifdef CONFIG_MEMORY_HOTREMOVE
1695 static int check_memblock_offlined_cb(struct memory_block
*mem
, void *arg
)
1697 int ret
= !is_memblock_offlined(mem
);
1699 if (unlikely(ret
)) {
1700 phys_addr_t beginpa
, endpa
;
1702 beginpa
= PFN_PHYS(section_nr_to_pfn(mem
->start_section_nr
));
1703 endpa
= PFN_PHYS(section_nr_to_pfn(mem
->end_section_nr
+ 1))-1;
1704 pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n",
1711 static int check_cpu_on_node(pg_data_t
*pgdat
)
1715 for_each_present_cpu(cpu
) {
1716 if (cpu_to_node(cpu
) == pgdat
->node_id
)
1718 * the cpu on this node isn't removed, and we can't
1719 * offline this node.
1727 static void unmap_cpu_on_node(pg_data_t
*pgdat
)
1729 #ifdef CONFIG_ACPI_NUMA
1732 for_each_possible_cpu(cpu
)
1733 if (cpu_to_node(cpu
) == pgdat
->node_id
)
1734 numa_clear_node(cpu
);
1738 static int check_and_unmap_cpu_on_node(pg_data_t
*pgdat
)
1742 ret
= check_cpu_on_node(pgdat
);
1747 * the node will be offlined when we come here, so we can clear
1748 * the cpu_to_node() now.
1751 unmap_cpu_on_node(pgdat
);
1759 * Offline a node if all memory sections and cpus of the node are removed.
1761 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
1762 * and online/offline operations before this call.
1764 void try_offline_node(int nid
)
1766 pg_data_t
*pgdat
= NODE_DATA(nid
);
1767 unsigned long start_pfn
= pgdat
->node_start_pfn
;
1768 unsigned long end_pfn
= start_pfn
+ pgdat
->node_spanned_pages
;
1771 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
1772 unsigned long section_nr
= pfn_to_section_nr(pfn
);
1774 if (!present_section_nr(section_nr
))
1777 if (pfn_to_nid(pfn
) != nid
)
1781 * some memory sections of this node are not removed, and we
1782 * can't offline node now.
1787 if (check_and_unmap_cpu_on_node(pgdat
))
1791 * all memory/cpu of this node are removed, we can offline this
1794 node_set_offline(nid
);
1795 unregister_one_node(nid
);
1797 EXPORT_SYMBOL(try_offline_node
);
1802 * @start: physical address of the region to remove
1803 * @size: size of the region to remove
1805 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
1806 * and online/offline operations before this call, as required by
1807 * try_offline_node().
1809 void __ref
remove_memory(int nid
, u64 start
, u64 size
)
1813 BUG_ON(check_hotplug_memory_range(start
, size
));
1815 mem_hotplug_begin();
1818 * All memory blocks must be offlined before removing memory. Check
1819 * whether all memory blocks in question are offline and trigger a BUG()
1820 * if this is not the case.
1822 ret
= walk_memory_range(PFN_DOWN(start
), PFN_UP(start
+ size
- 1), NULL
,
1823 check_memblock_offlined_cb
);
1827 /* remove memmap entry */
1828 firmware_map_remove(start
, start
+ size
, "System RAM");
1829 memblock_free(start
, size
);
1830 memblock_remove(start
, size
);
1832 arch_remove_memory(start
, size
, NULL
);
1834 try_offline_node(nid
);
1838 EXPORT_SYMBOL_GPL(remove_memory
);
1839 #endif /* CONFIG_MEMORY_HOTREMOVE */