2 * linux/mm/memory_hotplug.c
7 #include <linux/stddef.h>
9 #include <linux/swap.h>
10 #include <linux/interrupt.h>
11 #include <linux/pagemap.h>
12 #include <linux/bootmem.h>
13 #include <linux/compiler.h>
14 #include <linux/export.h>
15 #include <linux/pagevec.h>
16 #include <linux/writeback.h>
17 #include <linux/slab.h>
18 #include <linux/sysctl.h>
19 #include <linux/cpu.h>
20 #include <linux/memory.h>
21 #include <linux/memory_hotplug.h>
22 #include <linux/highmem.h>
23 #include <linux/vmalloc.h>
24 #include <linux/ioport.h>
25 #include <linux/delay.h>
26 #include <linux/migrate.h>
27 #include <linux/page-isolation.h>
28 #include <linux/pfn.h>
29 #include <linux/suspend.h>
30 #include <linux/mm_inline.h>
31 #include <linux/firmware-map.h>
32 #include <linux/stop_machine.h>
34 #include <asm/tlbflush.h>
39 * online_page_callback contains pointer to current page onlining function.
40 * Initially it is generic_online_page(). If it is required it could be
41 * changed by calling set_online_page_callback() for callback registration
42 * and restore_online_page_callback() for generic callback restore.
45 static void generic_online_page(struct page *page);
47 static online_page_callback_t online_page_callback = generic_online_page;
49 DEFINE_MUTEX(mem_hotplug_mutex);
51 void lock_memory_hotplug(void)
53 mutex_lock(&mem_hotplug_mutex);
55 /* for exclusive hibernation if CONFIG_HIBERNATION=y */
59 void unlock_memory_hotplug(void)
61 unlock_system_sleep();
62 mutex_unlock(&mem_hotplug_mutex);
66 /* add this memory to iomem resource */
67 static struct resource *register_memory_resource(u64 start, u64 size)
70 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
73 res->name = "System RAM";
75 res->end = start + size - 1;
76 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
77 if (request_resource(&iomem_resource, res) < 0) {
78 printk("System RAM resource %pR cannot be added\n", res);
85 static void release_memory_resource(struct resource *res)
89 release_resource(res);
94 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
95 void get_page_bootmem(unsigned long info, struct page *page,
98 page->lru.next = (struct list_head *) type;
100 set_page_private(page, info);
101 atomic_inc(&page->_count);
104 /* reference to __meminit __free_pages_bootmem is valid
105 * so use __ref to tell modpost not to generate a warning */
106 void __ref put_page_bootmem(struct page *page)
109 static DEFINE_MUTEX(ppb_lock);
111 type = (unsigned long) page->lru.next;
112 BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
113 type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE);
115 if (atomic_dec_return(&page->_count) == 1) {
116 ClearPagePrivate(page);
117 set_page_private(page, 0);
118 INIT_LIST_HEAD(&page->lru);
121 * Please refer to comment for __free_pages_bootmem()
122 * for why we serialize here.
124 mutex_lock(&ppb_lock);
125 __free_pages_bootmem(page, 0);
126 mutex_unlock(&ppb_lock);
132 #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
133 #ifndef CONFIG_SPARSEMEM_VMEMMAP
134 static void register_page_bootmem_info_section(unsigned long start_pfn)
136 unsigned long *usemap, mapsize, section_nr, i;
137 struct mem_section *ms;
138 struct page *page, *memmap;
140 section_nr = pfn_to_section_nr(start_pfn);
141 ms = __nr_to_section(section_nr);
143 /* Get section's memmap address */
144 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
147 * Get page for the memmap's phys address
148 * XXX: need more consideration for sparse_vmemmap...
150 page = virt_to_page(memmap);
151 mapsize = sizeof(struct page) * PAGES_PER_SECTION;
152 mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT;
154 /* remember memmap's page */
155 for (i = 0; i < mapsize; i++, page++)
156 get_page_bootmem(section_nr, page, SECTION_INFO);
158 usemap = __nr_to_section(section_nr)->pageblock_flags;
159 page = virt_to_page(usemap);
161 mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT;
163 for (i = 0; i < mapsize; i++, page++)
164 get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
167 #else /* CONFIG_SPARSEMEM_VMEMMAP */
168 static void register_page_bootmem_info_section(unsigned long start_pfn)
170 unsigned long *usemap, mapsize, section_nr, i;
171 struct mem_section *ms;
172 struct page *page, *memmap;
174 if (!pfn_valid(start_pfn))
177 section_nr = pfn_to_section_nr(start_pfn);
178 ms = __nr_to_section(section_nr);
180 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
182 register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION);
184 usemap = __nr_to_section(section_nr)->pageblock_flags;
185 page = virt_to_page(usemap);
187 mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT;
189 for (i = 0; i < mapsize; i++, page++)
190 get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
192 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
194 void register_page_bootmem_info_node(struct pglist_data *pgdat)
196 unsigned long i, pfn, end_pfn, nr_pages;
197 int node = pgdat->node_id;
201 nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT;
202 page = virt_to_page(pgdat);
204 for (i = 0; i < nr_pages; i++, page++)
205 get_page_bootmem(node, page, NODE_INFO);
207 zone = &pgdat->node_zones[0];
208 for (; zone < pgdat->node_zones + MAX_NR_ZONES - 1; zone++) {
209 if (zone->wait_table) {
210 nr_pages = zone->wait_table_hash_nr_entries
211 * sizeof(wait_queue_head_t);
212 nr_pages = PAGE_ALIGN(nr_pages) >> PAGE_SHIFT;
213 page = virt_to_page(zone->wait_table);
215 for (i = 0; i < nr_pages; i++, page++)
216 get_page_bootmem(node, page, NODE_INFO);
220 pfn = pgdat->node_start_pfn;
221 end_pfn = pfn + pgdat->node_spanned_pages;
223 /* register_section info */
224 for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
226 * Some platforms can assign the same pfn to multiple nodes - on
227 * node0 as well as nodeN. To avoid registering a pfn against
228 * multiple nodes we check that this pfn does not already
229 * reside in some other node.
231 if (pfn_valid(pfn) && (pfn_to_nid(pfn) == node))
232 register_page_bootmem_info_section(pfn);
235 #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */
237 static void grow_zone_span(struct zone *zone, unsigned long start_pfn,
238 unsigned long end_pfn)
240 unsigned long old_zone_end_pfn;
242 zone_span_writelock(zone);
244 old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
245 if (!zone->spanned_pages || start_pfn < zone->zone_start_pfn)
246 zone->zone_start_pfn = start_pfn;
248 zone->spanned_pages = max(old_zone_end_pfn, end_pfn) -
249 zone->zone_start_pfn;
251 zone_span_writeunlock(zone);
254 static void resize_zone(struct zone *zone, unsigned long start_pfn,
255 unsigned long end_pfn)
257 zone_span_writelock(zone);
259 if (end_pfn - start_pfn) {
260 zone->zone_start_pfn = start_pfn;
261 zone->spanned_pages = end_pfn - start_pfn;
264 * make it consist as free_area_init_core(),
265 * if spanned_pages = 0, then keep start_pfn = 0
267 zone->zone_start_pfn = 0;
268 zone->spanned_pages = 0;
271 zone_span_writeunlock(zone);
274 static void fix_zone_id(struct zone *zone, unsigned long start_pfn,
275 unsigned long end_pfn)
277 enum zone_type zid = zone_idx(zone);
278 int nid = zone->zone_pgdat->node_id;
281 for (pfn = start_pfn; pfn < end_pfn; pfn++)
282 set_page_links(pfn_to_page(pfn), zid, nid, pfn);
285 static int __meminit move_pfn_range_left(struct zone *z1, struct zone *z2,
286 unsigned long start_pfn, unsigned long end_pfn)
290 unsigned long z1_start_pfn;
292 if (!z1->wait_table) {
293 ret = init_currently_empty_zone(z1, start_pfn,
294 end_pfn - start_pfn, MEMMAP_HOTPLUG);
299 pgdat_resize_lock(z1->zone_pgdat, &flags);
301 /* can't move pfns which are higher than @z2 */
302 if (end_pfn > z2->zone_start_pfn + z2->spanned_pages)
304 /* the move out part mast at the left most of @z2 */
305 if (start_pfn > z2->zone_start_pfn)
307 /* must included/overlap */
308 if (end_pfn <= z2->zone_start_pfn)
311 /* use start_pfn for z1's start_pfn if z1 is empty */
312 if (z1->spanned_pages)
313 z1_start_pfn = z1->zone_start_pfn;
315 z1_start_pfn = start_pfn;
317 resize_zone(z1, z1_start_pfn, end_pfn);
318 resize_zone(z2, end_pfn, z2->zone_start_pfn + z2->spanned_pages);
320 pgdat_resize_unlock(z1->zone_pgdat, &flags);
322 fix_zone_id(z1, start_pfn, end_pfn);
326 pgdat_resize_unlock(z1->zone_pgdat, &flags);
330 static int __meminit move_pfn_range_right(struct zone *z1, struct zone *z2,
331 unsigned long start_pfn, unsigned long end_pfn)
335 unsigned long z2_end_pfn;
337 if (!z2->wait_table) {
338 ret = init_currently_empty_zone(z2, start_pfn,
339 end_pfn - start_pfn, MEMMAP_HOTPLUG);
344 pgdat_resize_lock(z1->zone_pgdat, &flags);
346 /* can't move pfns which are lower than @z1 */
347 if (z1->zone_start_pfn > start_pfn)
349 /* the move out part mast at the right most of @z1 */
350 if (z1->zone_start_pfn + z1->spanned_pages > end_pfn)
352 /* must included/overlap */
353 if (start_pfn >= z1->zone_start_pfn + z1->spanned_pages)
356 /* use end_pfn for z2's end_pfn if z2 is empty */
357 if (z2->spanned_pages)
358 z2_end_pfn = z2->zone_start_pfn + z2->spanned_pages;
360 z2_end_pfn = end_pfn;
362 resize_zone(z1, z1->zone_start_pfn, start_pfn);
363 resize_zone(z2, start_pfn, z2_end_pfn);
365 pgdat_resize_unlock(z1->zone_pgdat, &flags);
367 fix_zone_id(z2, start_pfn, end_pfn);
371 pgdat_resize_unlock(z1->zone_pgdat, &flags);
375 static void grow_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn,
376 unsigned long end_pfn)
378 unsigned long old_pgdat_end_pfn =
379 pgdat->node_start_pfn + pgdat->node_spanned_pages;
381 if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn)
382 pgdat->node_start_pfn = start_pfn;
384 pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) -
385 pgdat->node_start_pfn;
388 static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn)
390 struct pglist_data *pgdat = zone->zone_pgdat;
391 int nr_pages = PAGES_PER_SECTION;
392 int nid = pgdat->node_id;
396 zone_type = zone - pgdat->node_zones;
397 if (!zone->wait_table) {
400 ret = init_currently_empty_zone(zone, phys_start_pfn,
401 nr_pages, MEMMAP_HOTPLUG);
405 pgdat_resize_lock(zone->zone_pgdat, &flags);
406 grow_zone_span(zone, phys_start_pfn, phys_start_pfn + nr_pages);
407 grow_pgdat_span(zone->zone_pgdat, phys_start_pfn,
408 phys_start_pfn + nr_pages);
409 pgdat_resize_unlock(zone->zone_pgdat, &flags);
410 memmap_init_zone(nr_pages, nid, zone_type,
411 phys_start_pfn, MEMMAP_HOTPLUG);
415 static int __meminit __add_section(int nid, struct zone *zone,
416 unsigned long phys_start_pfn)
418 int nr_pages = PAGES_PER_SECTION;
421 if (pfn_valid(phys_start_pfn))
424 ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
429 ret = __add_zone(zone, phys_start_pfn);
434 return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
437 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */
438 static int find_smallest_section_pfn(int nid, struct zone *zone,
439 unsigned long start_pfn,
440 unsigned long end_pfn)
442 struct mem_section *ms;
444 for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SECTION) {
445 ms = __pfn_to_section(start_pfn);
447 if (unlikely(!valid_section(ms)))
450 if (unlikely(pfn_to_nid(start_pfn) != nid))
453 if (zone && zone != page_zone(pfn_to_page(start_pfn)))
462 /* find the biggest valid pfn in the range [start_pfn, end_pfn). */
463 static int find_biggest_section_pfn(int nid, struct zone *zone,
464 unsigned long start_pfn,
465 unsigned long end_pfn)
467 struct mem_section *ms;
470 /* pfn is the end pfn of a memory section. */
472 for (; pfn >= start_pfn; pfn -= PAGES_PER_SECTION) {
473 ms = __pfn_to_section(pfn);
475 if (unlikely(!valid_section(ms)))
478 if (unlikely(pfn_to_nid(pfn) != nid))
481 if (zone && zone != page_zone(pfn_to_page(pfn)))
490 static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
491 unsigned long end_pfn)
493 unsigned long zone_start_pfn = zone->zone_start_pfn;
494 unsigned long zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
496 struct mem_section *ms;
497 int nid = zone_to_nid(zone);
499 zone_span_writelock(zone);
500 if (zone_start_pfn == start_pfn) {
502 * If the section is smallest section in the zone, it need
503 * shrink zone->zone_start_pfn and zone->zone_spanned_pages.
504 * In this case, we find second smallest valid mem_section
505 * for shrinking zone.
507 pfn = find_smallest_section_pfn(nid, zone, end_pfn,
510 zone->zone_start_pfn = pfn;
511 zone->spanned_pages = zone_end_pfn - pfn;
513 } else if (zone_end_pfn == end_pfn) {
515 * If the section is biggest section in the zone, it need
516 * shrink zone->spanned_pages.
517 * In this case, we find second biggest valid mem_section for
520 pfn = find_biggest_section_pfn(nid, zone, zone_start_pfn,
523 zone->spanned_pages = pfn - zone_start_pfn + 1;
527 * The section is not biggest or smallest mem_section in the zone, it
528 * only creates a hole in the zone. So in this case, we need not
529 * change the zone. But perhaps, the zone has only hole data. Thus
530 * it check the zone has only hole or not.
532 pfn = zone_start_pfn;
533 for (; pfn < zone_end_pfn; pfn += PAGES_PER_SECTION) {
534 ms = __pfn_to_section(pfn);
536 if (unlikely(!valid_section(ms)))
539 if (page_zone(pfn_to_page(pfn)) != zone)
542 /* If the section is current section, it continues the loop */
543 if (start_pfn == pfn)
546 /* If we find valid section, we have nothing to do */
547 zone_span_writeunlock(zone);
551 /* The zone has no valid section */
552 zone->zone_start_pfn = 0;
553 zone->spanned_pages = 0;
554 zone_span_writeunlock(zone);
557 static void shrink_pgdat_span(struct pglist_data *pgdat,
558 unsigned long start_pfn, unsigned long end_pfn)
560 unsigned long pgdat_start_pfn = pgdat->node_start_pfn;
561 unsigned long pgdat_end_pfn =
562 pgdat->node_start_pfn + pgdat->node_spanned_pages;
564 struct mem_section *ms;
565 int nid = pgdat->node_id;
567 if (pgdat_start_pfn == start_pfn) {
569 * If the section is smallest section in the pgdat, it need
570 * shrink pgdat->node_start_pfn and pgdat->node_spanned_pages.
571 * In this case, we find second smallest valid mem_section
572 * for shrinking zone.
574 pfn = find_smallest_section_pfn(nid, NULL, end_pfn,
577 pgdat->node_start_pfn = pfn;
578 pgdat->node_spanned_pages = pgdat_end_pfn - pfn;
580 } else if (pgdat_end_pfn == end_pfn) {
582 * If the section is biggest section in the pgdat, it need
583 * shrink pgdat->node_spanned_pages.
584 * In this case, we find second biggest valid mem_section for
587 pfn = find_biggest_section_pfn(nid, NULL, pgdat_start_pfn,
590 pgdat->node_spanned_pages = pfn - pgdat_start_pfn + 1;
594 * If the section is not biggest or smallest mem_section in the pgdat,
595 * it only creates a hole in the pgdat. So in this case, we need not
597 * But perhaps, the pgdat has only hole data. Thus it check the pgdat
598 * has only hole or not.
600 pfn = pgdat_start_pfn;
601 for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SECTION) {
602 ms = __pfn_to_section(pfn);
604 if (unlikely(!valid_section(ms)))
607 if (pfn_to_nid(pfn) != nid)
610 /* If the section is current section, it continues the loop */
611 if (start_pfn == pfn)
614 /* If we find valid section, we have nothing to do */
618 /* The pgdat has no valid section */
619 pgdat->node_start_pfn = 0;
620 pgdat->node_spanned_pages = 0;
623 static void __remove_zone(struct zone *zone, unsigned long start_pfn)
625 struct pglist_data *pgdat = zone->zone_pgdat;
626 int nr_pages = PAGES_PER_SECTION;
630 zone_type = zone - pgdat->node_zones;
632 pgdat_resize_lock(zone->zone_pgdat, &flags);
633 shrink_zone_span(zone, start_pfn, start_pfn + nr_pages);
634 shrink_pgdat_span(pgdat, start_pfn, start_pfn + nr_pages);
635 pgdat_resize_unlock(zone->zone_pgdat, &flags);
638 static int __remove_section(struct zone *zone, struct mem_section *ms)
640 unsigned long start_pfn;
644 if (!valid_section(ms))
647 ret = unregister_memory_section(ms);
651 scn_nr = __section_nr(ms);
652 start_pfn = section_nr_to_pfn(scn_nr);
653 __remove_zone(zone, start_pfn);
655 sparse_remove_one_section(zone, ms);
660 * Reasonably generic function for adding memory. It is
661 * expected that archs that support memory hotplug will
662 * call this function after deciding the zone to which to
665 int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,
666 unsigned long nr_pages)
670 int start_sec, end_sec;
671 /* during initialize mem_map, align hot-added range to section */
672 start_sec = pfn_to_section_nr(phys_start_pfn);
673 end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
675 for (i = start_sec; i <= end_sec; i++) {
676 err = __add_section(nid, zone, i << PFN_SECTION_SHIFT);
679 * EEXIST is finally dealt with by ioresource collision
680 * check. see add_memory() => register_memory_resource()
681 * Warning will be printed if there is collision.
683 if (err && (err != -EEXIST))
690 EXPORT_SYMBOL_GPL(__add_pages);
693 * __remove_pages() - remove sections of pages from a zone
694 * @zone: zone from which pages need to be removed
695 * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
696 * @nr_pages: number of pages to remove (must be multiple of section size)
698 * Generic helper function to remove section mappings and sysfs entries
699 * for the section of the memory we are removing. Caller needs to make
700 * sure that pages are marked reserved and zones are adjust properly by
701 * calling offline_pages().
703 int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
704 unsigned long nr_pages)
706 unsigned long i, ret = 0;
707 int sections_to_remove;
710 * We can only remove entire sections
712 BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK);
713 BUG_ON(nr_pages % PAGES_PER_SECTION);
715 release_mem_region(phys_start_pfn << PAGE_SHIFT, nr_pages * PAGE_SIZE);
717 sections_to_remove = nr_pages / PAGES_PER_SECTION;
718 for (i = 0; i < sections_to_remove; i++) {
719 unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
720 ret = __remove_section(zone, __pfn_to_section(pfn));
726 EXPORT_SYMBOL_GPL(__remove_pages);
728 int set_online_page_callback(online_page_callback_t callback)
732 lock_memory_hotplug();
734 if (online_page_callback == generic_online_page) {
735 online_page_callback = callback;
739 unlock_memory_hotplug();
743 EXPORT_SYMBOL_GPL(set_online_page_callback);
745 int restore_online_page_callback(online_page_callback_t callback)
749 lock_memory_hotplug();
751 if (online_page_callback == callback) {
752 online_page_callback = generic_online_page;
756 unlock_memory_hotplug();
760 EXPORT_SYMBOL_GPL(restore_online_page_callback);
762 void __online_page_set_limits(struct page *page)
764 unsigned long pfn = page_to_pfn(page);
766 if (pfn >= num_physpages)
767 num_physpages = pfn + 1;
769 EXPORT_SYMBOL_GPL(__online_page_set_limits);
771 void __online_page_increment_counters(struct page *page)
775 #ifdef CONFIG_HIGHMEM
776 if (PageHighMem(page))
780 EXPORT_SYMBOL_GPL(__online_page_increment_counters);
782 void __online_page_free(struct page *page)
784 ClearPageReserved(page);
785 init_page_count(page);
788 EXPORT_SYMBOL_GPL(__online_page_free);
790 static void generic_online_page(struct page *page)
792 __online_page_set_limits(page);
793 __online_page_increment_counters(page);
794 __online_page_free(page);
797 static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
801 unsigned long onlined_pages = *(unsigned long *)arg;
803 if (PageReserved(pfn_to_page(start_pfn)))
804 for (i = 0; i < nr_pages; i++) {
805 page = pfn_to_page(start_pfn + i);
806 (*online_page_callback)(page);
809 *(unsigned long *)arg = onlined_pages;
813 #ifdef CONFIG_MOVABLE_NODE
815 * When CONFIG_MOVABLE_NODE, we permit onlining of a node which doesn't have
818 static bool can_online_high_movable(struct zone *zone)
822 #else /* CONFIG_MOVABLE_NODE */
823 /* ensure every online node has NORMAL memory */
824 static bool can_online_high_movable(struct zone *zone)
826 return node_state(zone_to_nid(zone), N_NORMAL_MEMORY);
828 #endif /* CONFIG_MOVABLE_NODE */
830 /* check which state of node_states will be changed when online memory */
831 static void node_states_check_changes_online(unsigned long nr_pages,
832 struct zone *zone, struct memory_notify *arg)
834 int nid = zone_to_nid(zone);
835 enum zone_type zone_last = ZONE_NORMAL;
838 * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
839 * contains nodes which have zones of 0...ZONE_NORMAL,
840 * set zone_last to ZONE_NORMAL.
842 * If we don't have HIGHMEM nor movable node,
843 * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
844 * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
846 if (N_MEMORY == N_NORMAL_MEMORY)
847 zone_last = ZONE_MOVABLE;
850 * if the memory to be online is in a zone of 0...zone_last, and
851 * the zones of 0...zone_last don't have memory before online, we will
852 * need to set the node to node_states[N_NORMAL_MEMORY] after
853 * the memory is online.
855 if (zone_idx(zone) <= zone_last && !node_state(nid, N_NORMAL_MEMORY))
856 arg->status_change_nid_normal = nid;
858 arg->status_change_nid_normal = -1;
860 #ifdef CONFIG_HIGHMEM
862 * If we have movable node, node_states[N_HIGH_MEMORY]
863 * contains nodes which have zones of 0...ZONE_HIGHMEM,
864 * set zone_last to ZONE_HIGHMEM.
866 * If we don't have movable node, node_states[N_NORMAL_MEMORY]
867 * contains nodes which have zones of 0...ZONE_MOVABLE,
868 * set zone_last to ZONE_MOVABLE.
870 zone_last = ZONE_HIGHMEM;
871 if (N_MEMORY == N_HIGH_MEMORY)
872 zone_last = ZONE_MOVABLE;
874 if (zone_idx(zone) <= zone_last && !node_state(nid, N_HIGH_MEMORY))
875 arg->status_change_nid_high = nid;
877 arg->status_change_nid_high = -1;
879 arg->status_change_nid_high = arg->status_change_nid_normal;
883 * if the node don't have memory befor online, we will need to
884 * set the node to node_states[N_MEMORY] after the memory
887 if (!node_state(nid, N_MEMORY))
888 arg->status_change_nid = nid;
890 arg->status_change_nid = -1;
893 static void node_states_set_node(int node, struct memory_notify *arg)
895 if (arg->status_change_nid_normal >= 0)
896 node_set_state(node, N_NORMAL_MEMORY);
898 if (arg->status_change_nid_high >= 0)
899 node_set_state(node, N_HIGH_MEMORY);
901 node_set_state(node, N_MEMORY);
905 int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type)
907 unsigned long onlined_pages = 0;
909 int need_zonelists_rebuild = 0;
912 struct memory_notify arg;
914 lock_memory_hotplug();
916 * This doesn't need a lock to do pfn_to_page().
917 * The section can't be removed here because of the
918 * memory_block->state_mutex.
920 zone = page_zone(pfn_to_page(pfn));
922 if ((zone_idx(zone) > ZONE_NORMAL || online_type == ONLINE_MOVABLE) &&
923 !can_online_high_movable(zone)) {
924 unlock_memory_hotplug();
928 if (online_type == ONLINE_KERNEL && zone_idx(zone) == ZONE_MOVABLE) {
929 if (move_pfn_range_left(zone - 1, zone, pfn, pfn + nr_pages)) {
930 unlock_memory_hotplug();
934 if (online_type == ONLINE_MOVABLE && zone_idx(zone) == ZONE_MOVABLE - 1) {
935 if (move_pfn_range_right(zone, zone + 1, pfn, pfn + nr_pages)) {
936 unlock_memory_hotplug();
941 /* Previous code may changed the zone of the pfn range */
942 zone = page_zone(pfn_to_page(pfn));
945 arg.nr_pages = nr_pages;
946 node_states_check_changes_online(nr_pages, zone, &arg);
948 nid = page_to_nid(pfn_to_page(pfn));
950 ret = memory_notify(MEM_GOING_ONLINE, &arg);
951 ret = notifier_to_errno(ret);
953 memory_notify(MEM_CANCEL_ONLINE, &arg);
954 unlock_memory_hotplug();
958 * If this zone is not populated, then it is not in zonelist.
959 * This means the page allocator ignores this zone.
960 * So, zonelist must be updated after online.
962 mutex_lock(&zonelists_mutex);
963 if (!populated_zone(zone)) {
964 need_zonelists_rebuild = 1;
965 build_all_zonelists(NULL, zone);
968 ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages,
971 if (need_zonelists_rebuild)
972 zone_pcp_reset(zone);
973 mutex_unlock(&zonelists_mutex);
974 printk(KERN_DEBUG "online_pages [mem %#010llx-%#010llx] failed\n",
975 (unsigned long long) pfn << PAGE_SHIFT,
976 (((unsigned long long) pfn + nr_pages)
978 memory_notify(MEM_CANCEL_ONLINE, &arg);
979 unlock_memory_hotplug();
983 zone->managed_pages += onlined_pages;
984 zone->present_pages += onlined_pages;
985 zone->zone_pgdat->node_present_pages += onlined_pages;
987 node_states_set_node(zone_to_nid(zone), &arg);
988 if (need_zonelists_rebuild)
989 build_all_zonelists(NULL, NULL);
991 zone_pcp_update(zone);
994 mutex_unlock(&zonelists_mutex);
996 init_per_zone_wmark_min();
999 kswapd_run(zone_to_nid(zone));
1001 vm_total_pages = nr_free_pagecache_pages();
1003 writeback_set_ratelimit();
1006 memory_notify(MEM_ONLINE, &arg);
1007 unlock_memory_hotplug();
1011 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
1013 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
1014 static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
1016 struct pglist_data *pgdat;
1017 unsigned long zones_size[MAX_NR_ZONES] = {0};
1018 unsigned long zholes_size[MAX_NR_ZONES] = {0};
1019 unsigned long start_pfn = start >> PAGE_SHIFT;
1021 pgdat = NODE_DATA(nid);
1023 pgdat = arch_alloc_nodedata(nid);
1027 arch_refresh_nodedata(nid, pgdat);
1030 /* we can use NODE_DATA(nid) from here */
1032 /* init node's zones as empty zones, we don't have any present pages.*/
1033 free_area_init_node(nid, zones_size, start_pfn, zholes_size);
1036 * The node we allocated has no zone fallback lists. For avoiding
1037 * to access not-initialized zonelist, build here.
1039 mutex_lock(&zonelists_mutex);
1040 build_all_zonelists(pgdat, NULL);
1041 mutex_unlock(&zonelists_mutex);
1046 static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
1048 arch_refresh_nodedata(nid, NULL);
1049 arch_free_nodedata(pgdat);
1055 * called by cpu_up() to online a node without onlined memory.
1057 int mem_online_node(int nid)
1062 lock_memory_hotplug();
1063 pgdat = hotadd_new_pgdat(nid, 0);
1068 node_set_online(nid);
1069 ret = register_one_node(nid);
1073 unlock_memory_hotplug();
1077 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
1078 int __ref add_memory(int nid, u64 start, u64 size)
1080 pg_data_t *pgdat = NULL;
1083 struct resource *res;
1086 lock_memory_hotplug();
1088 res = register_memory_resource(start, size);
1093 { /* Stupid hack to suppress address-never-null warning */
1094 void *p = NODE_DATA(nid);
1097 new_node = !node_online(nid);
1099 pgdat = hotadd_new_pgdat(nid, start);
1105 /* call arch's memory hotadd */
1106 ret = arch_add_memory(nid, start, size);
1111 /* we online node here. we can't roll back from here. */
1112 node_set_online(nid);
1115 ret = register_one_node(nid);
1117 * If sysfs file of new node can't create, cpu on the node
1118 * can't be hot-added. There is no rollback way now.
1119 * So, check by BUG_ON() to catch it reluctantly..
1124 /* create new memmap entry */
1125 firmware_map_add_hotplug(start, start + size, "System RAM");
1130 /* rollback pgdat allocation and others */
1132 rollback_node_hotadd(nid, pgdat);
1133 release_memory_resource(res);
1136 unlock_memory_hotplug();
1139 EXPORT_SYMBOL_GPL(add_memory);
1141 #ifdef CONFIG_MEMORY_HOTREMOVE
1143 * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
1144 * set and the size of the free page is given by page_order(). Using this,
1145 * the function determines if the pageblock contains only free pages.
1146 * Due to buddy contraints, a free page at least the size of a pageblock will
1147 * be located at the start of the pageblock
1149 static inline int pageblock_free(struct page *page)
1151 return PageBuddy(page) && page_order(page) >= pageblock_order;
1154 /* Return the start of the next active pageblock after a given page */
1155 static struct page *next_active_pageblock(struct page *page)
1157 /* Ensure the starting page is pageblock-aligned */
1158 BUG_ON(page_to_pfn(page) & (pageblock_nr_pages - 1));
1160 /* If the entire pageblock is free, move to the end of free page */
1161 if (pageblock_free(page)) {
1163 /* be careful. we don't have locks, page_order can be changed.*/
1164 order = page_order(page);
1165 if ((order < MAX_ORDER) && (order >= pageblock_order))
1166 return page + (1 << order);
1169 return page + pageblock_nr_pages;
1172 /* Checks if this range of memory is likely to be hot-removable. */
1173 int is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages)
1175 struct page *page = pfn_to_page(start_pfn);
1176 struct page *end_page = page + nr_pages;
1178 /* Check the starting page of each pageblock within the range */
1179 for (; page < end_page; page = next_active_pageblock(page)) {
1180 if (!is_pageblock_removable_nolock(page))
1185 /* All pageblocks in the memory block are likely to be hot-removable */
1190 * Confirm all pages in a range [start, end) is belongs to the same zone.
1192 static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn)
1195 struct zone *zone = NULL;
1198 for (pfn = start_pfn;
1200 pfn += MAX_ORDER_NR_PAGES) {
1202 /* This is just a CONFIG_HOLES_IN_ZONE check.*/
1203 while ((i < MAX_ORDER_NR_PAGES) && !pfn_valid_within(pfn + i))
1205 if (i == MAX_ORDER_NR_PAGES)
1207 page = pfn_to_page(pfn + i);
1208 if (zone && page_zone(page) != zone)
1210 zone = page_zone(page);
1216 * Scanning pfn is much easier than scanning lru list.
1217 * Scan pfn from start to end and Find LRU page.
1219 static unsigned long scan_lru_pages(unsigned long start, unsigned long end)
1223 for (pfn = start; pfn < end; pfn++) {
1224 if (pfn_valid(pfn)) {
1225 page = pfn_to_page(pfn);
1233 #define NR_OFFLINE_AT_ONCE_PAGES (256)
1235 do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
1239 int move_pages = NR_OFFLINE_AT_ONCE_PAGES;
1240 int not_managed = 0;
1244 for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) {
1245 if (!pfn_valid(pfn))
1247 page = pfn_to_page(pfn);
1248 if (!get_page_unless_zero(page))
1251 * We can skip free pages. And we can only deal with pages on
1254 ret = isolate_lru_page(page);
1255 if (!ret) { /* Success */
1257 list_add_tail(&page->lru, &source);
1259 inc_zone_page_state(page, NR_ISOLATED_ANON +
1260 page_is_file_cache(page));
1263 #ifdef CONFIG_DEBUG_VM
1264 printk(KERN_ALERT "removing pfn %lx from LRU failed\n",
1269 /* Because we don't have big zone->lock. we should
1270 check this again here. */
1271 if (page_count(page)) {
1278 if (!list_empty(&source)) {
1280 putback_lru_pages(&source);
1285 * alloc_migrate_target should be improooooved!!
1286 * migrate_pages returns # of failed pages.
1288 ret = migrate_pages(&source, alloc_migrate_target, 0,
1292 putback_lru_pages(&source);
1299 * remove from free_area[] and mark all as Reserved.
1302 offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
1305 __offline_isolated_pages(start, start + nr_pages);
1310 offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
1312 walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL,
1313 offline_isolated_pages_cb);
1317 * Check all pages in range, recoreded as memory resource, are isolated.
1320 check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
1324 long offlined = *(long *)data;
1325 ret = test_pages_isolated(start_pfn, start_pfn + nr_pages, true);
1326 offlined = nr_pages;
1328 *(long *)data += offlined;
1333 check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
1338 ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined,
1339 check_pages_isolated_cb);
1341 offlined = (long)ret;
1345 #ifdef CONFIG_MOVABLE_NODE
1347 * When CONFIG_MOVABLE_NODE, we permit offlining of a node which doesn't have
1350 static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)
1354 #else /* CONFIG_MOVABLE_NODE */
1355 /* ensure the node has NORMAL memory if it is still online */
1356 static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)
1358 struct pglist_data *pgdat = zone->zone_pgdat;
1359 unsigned long present_pages = 0;
1362 for (zt = 0; zt <= ZONE_NORMAL; zt++)
1363 present_pages += pgdat->node_zones[zt].present_pages;
1365 if (present_pages > nr_pages)
1369 for (; zt <= ZONE_MOVABLE; zt++)
1370 present_pages += pgdat->node_zones[zt].present_pages;
1373 * we can't offline the last normal memory until all
1374 * higher memory is offlined.
1376 return present_pages == 0;
1378 #endif /* CONFIG_MOVABLE_NODE */
1380 /* check which state of node_states will be changed when offline memory */
1381 static void node_states_check_changes_offline(unsigned long nr_pages,
1382 struct zone *zone, struct memory_notify *arg)
1384 struct pglist_data *pgdat = zone->zone_pgdat;
1385 unsigned long present_pages = 0;
1386 enum zone_type zt, zone_last = ZONE_NORMAL;
1389 * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
1390 * contains nodes which have zones of 0...ZONE_NORMAL,
1391 * set zone_last to ZONE_NORMAL.
1393 * If we don't have HIGHMEM nor movable node,
1394 * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
1395 * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
1397 if (N_MEMORY == N_NORMAL_MEMORY)
1398 zone_last = ZONE_MOVABLE;
1401 * check whether node_states[N_NORMAL_MEMORY] will be changed.
1402 * If the memory to be offline is in a zone of 0...zone_last,
1403 * and it is the last present memory, 0...zone_last will
1404 * become empty after offline , thus we can determind we will
1405 * need to clear the node from node_states[N_NORMAL_MEMORY].
1407 for (zt = 0; zt <= zone_last; zt++)
1408 present_pages += pgdat->node_zones[zt].present_pages;
1409 if (zone_idx(zone) <= zone_last && nr_pages >= present_pages)
1410 arg->status_change_nid_normal = zone_to_nid(zone);
1412 arg->status_change_nid_normal = -1;
1414 #ifdef CONFIG_HIGHMEM
1416 * If we have movable node, node_states[N_HIGH_MEMORY]
1417 * contains nodes which have zones of 0...ZONE_HIGHMEM,
1418 * set zone_last to ZONE_HIGHMEM.
1420 * If we don't have movable node, node_states[N_NORMAL_MEMORY]
1421 * contains nodes which have zones of 0...ZONE_MOVABLE,
1422 * set zone_last to ZONE_MOVABLE.
1424 zone_last = ZONE_HIGHMEM;
1425 if (N_MEMORY == N_HIGH_MEMORY)
1426 zone_last = ZONE_MOVABLE;
1428 for (; zt <= zone_last; zt++)
1429 present_pages += pgdat->node_zones[zt].present_pages;
1430 if (zone_idx(zone) <= zone_last && nr_pages >= present_pages)
1431 arg->status_change_nid_high = zone_to_nid(zone);
1433 arg->status_change_nid_high = -1;
1435 arg->status_change_nid_high = arg->status_change_nid_normal;
1439 * node_states[N_HIGH_MEMORY] contains nodes which have 0...ZONE_MOVABLE
1441 zone_last = ZONE_MOVABLE;
1444 * check whether node_states[N_HIGH_MEMORY] will be changed
1445 * If we try to offline the last present @nr_pages from the node,
1446 * we can determind we will need to clear the node from
1447 * node_states[N_HIGH_MEMORY].
1449 for (; zt <= zone_last; zt++)
1450 present_pages += pgdat->node_zones[zt].present_pages;
1451 if (nr_pages >= present_pages)
1452 arg->status_change_nid = zone_to_nid(zone);
1454 arg->status_change_nid = -1;
1457 static void node_states_clear_node(int node, struct memory_notify *arg)
1459 if (arg->status_change_nid_normal >= 0)
1460 node_clear_state(node, N_NORMAL_MEMORY);
1462 if ((N_MEMORY != N_NORMAL_MEMORY) &&
1463 (arg->status_change_nid_high >= 0))
1464 node_clear_state(node, N_HIGH_MEMORY);
1466 if ((N_MEMORY != N_HIGH_MEMORY) &&
1467 (arg->status_change_nid >= 0))
1468 node_clear_state(node, N_MEMORY);
1471 static int __ref __offline_pages(unsigned long start_pfn,
1472 unsigned long end_pfn, unsigned long timeout)
1474 unsigned long pfn, nr_pages, expire;
1475 long offlined_pages;
1476 int ret, drain, retry_max, node;
1478 struct memory_notify arg;
1480 BUG_ON(start_pfn >= end_pfn);
1481 /* at least, alignment against pageblock is necessary */
1482 if (!IS_ALIGNED(start_pfn, pageblock_nr_pages))
1484 if (!IS_ALIGNED(end_pfn, pageblock_nr_pages))
1486 /* This makes hotplug much easier...and readable.
1487 we assume this for now. .*/
1488 if (!test_pages_in_a_zone(start_pfn, end_pfn))
1491 lock_memory_hotplug();
1493 zone = page_zone(pfn_to_page(start_pfn));
1494 node = zone_to_nid(zone);
1495 nr_pages = end_pfn - start_pfn;
1498 if (zone_idx(zone) <= ZONE_NORMAL && !can_offline_normal(zone, nr_pages))
1501 /* set above range as isolated */
1502 ret = start_isolate_page_range(start_pfn, end_pfn,
1503 MIGRATE_MOVABLE, true);
1507 arg.start_pfn = start_pfn;
1508 arg.nr_pages = nr_pages;
1509 node_states_check_changes_offline(nr_pages, zone, &arg);
1511 ret = memory_notify(MEM_GOING_OFFLINE, &arg);
1512 ret = notifier_to_errno(ret);
1514 goto failed_removal;
1517 expire = jiffies + timeout;
1521 /* start memory hot removal */
1523 if (time_after(jiffies, expire))
1524 goto failed_removal;
1526 if (signal_pending(current))
1527 goto failed_removal;
1530 lru_add_drain_all();
1535 pfn = scan_lru_pages(start_pfn, end_pfn);
1536 if (pfn) { /* We have page on LRU */
1537 ret = do_migrate_range(pfn, end_pfn);
1543 if (--retry_max == 0)
1544 goto failed_removal;
1550 /* drain all zone's lru pagevec, this is asynchronous... */
1551 lru_add_drain_all();
1553 /* drain pcp pages, this is synchronous. */
1556 offlined_pages = check_pages_isolated(start_pfn, end_pfn);
1557 if (offlined_pages < 0) {
1559 goto failed_removal;
1561 printk(KERN_INFO "Offlined Pages %ld\n", offlined_pages);
1562 /* Ok, all of our target is isolated.
1563 We cannot do rollback at this point. */
1564 offline_isolated_pages(start_pfn, end_pfn);
1565 /* reset pagetype flags and makes migrate type to be MOVABLE */
1566 undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
1567 /* removal success */
1568 zone->managed_pages -= offlined_pages;
1569 zone->present_pages -= offlined_pages;
1570 zone->zone_pgdat->node_present_pages -= offlined_pages;
1571 totalram_pages -= offlined_pages;
1573 init_per_zone_wmark_min();
1575 if (!populated_zone(zone)) {
1576 zone_pcp_reset(zone);
1577 mutex_lock(&zonelists_mutex);
1578 build_all_zonelists(NULL, NULL);
1579 mutex_unlock(&zonelists_mutex);
1581 zone_pcp_update(zone);
1583 node_states_clear_node(node, &arg);
1584 if (arg.status_change_nid >= 0)
1587 vm_total_pages = nr_free_pagecache_pages();
1588 writeback_set_ratelimit();
1590 memory_notify(MEM_OFFLINE, &arg);
1591 unlock_memory_hotplug();
1595 printk(KERN_INFO "memory offlining [mem %#010llx-%#010llx] failed\n",
1596 (unsigned long long) start_pfn << PAGE_SHIFT,
1597 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1);
1598 memory_notify(MEM_CANCEL_OFFLINE, &arg);
1599 /* pushback to free area */
1600 undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
1603 unlock_memory_hotplug();
1607 int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
1609 return __offline_pages(start_pfn, start_pfn + nr_pages, 120 * HZ);
1613 * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn)
1614 * @start_pfn: start pfn of the memory range
1615 * @end_pfn: end pft of the memory range
1616 * @arg: argument passed to func
1617 * @func: callback for each memory section walked
1619 * This function walks through all present mem sections in range
1620 * [start_pfn, end_pfn) and call func on each mem section.
1622 * Returns the return value of func.
1624 static int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
1625 void *arg, int (*func)(struct memory_block *, void *))
1627 struct memory_block *mem = NULL;
1628 struct mem_section *section;
1629 unsigned long pfn, section_nr;
1632 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
1633 section_nr = pfn_to_section_nr(pfn);
1634 if (!present_section_nr(section_nr))
1637 section = __nr_to_section(section_nr);
1638 /* same memblock? */
1640 if ((section_nr >= mem->start_section_nr) &&
1641 (section_nr <= mem->end_section_nr))
1644 mem = find_memory_block_hinted(section, mem);
1648 ret = func(mem, arg);
1650 kobject_put(&mem->dev.kobj);
1656 kobject_put(&mem->dev.kobj);
1662 * offline_memory_block_cb - callback function for offlining memory block
1663 * @mem: the memory block to be offlined
1664 * @arg: buffer to hold error msg
1666 * Always return 0, and put the error msg in arg if any.
1668 static int offline_memory_block_cb(struct memory_block *mem, void *arg)
1671 int error = offline_memory_block(mem);
1673 if (error != 0 && *ret == 0)
1679 static int is_memblock_offlined_cb(struct memory_block *mem, void *arg)
1681 int ret = !is_memblock_offlined(mem);
1684 pr_warn("removing memory fails, because memory "
1685 "[%#010llx-%#010llx] is onlined\n",
1686 PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)),
1687 PFN_PHYS(section_nr_to_pfn(mem->end_section_nr + 1))-1);
1692 static int check_cpu_on_node(void *data)
1694 struct pglist_data *pgdat = data;
1697 for_each_present_cpu(cpu) {
1698 if (cpu_to_node(cpu) == pgdat->node_id)
1700 * the cpu on this node isn't removed, and we can't
1701 * offline this node.
1709 static void unmap_cpu_on_node(void *data)
1711 #ifdef CONFIG_ACPI_NUMA
1712 struct pglist_data *pgdat = data;
1715 for_each_possible_cpu(cpu)
1716 if (cpu_to_node(cpu) == pgdat->node_id)
1717 numa_clear_node(cpu);
1721 static int check_and_unmap_cpu_on_node(void *data)
1723 int ret = check_cpu_on_node(data);
1729 * the node will be offlined when we come here, so we can clear
1730 * the cpu_to_node() now.
1733 unmap_cpu_on_node(data);
1737 /* offline the node if all memory sections of this node are removed */
1738 void try_offline_node(int nid)
1740 pg_data_t *pgdat = NODE_DATA(nid);
1741 unsigned long start_pfn = pgdat->node_start_pfn;
1742 unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages;
1744 struct page *pgdat_page = virt_to_page(pgdat);
1747 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
1748 unsigned long section_nr = pfn_to_section_nr(pfn);
1750 if (!present_section_nr(section_nr))
1753 if (pfn_to_nid(pfn) != nid)
1757 * some memory sections of this node are not removed, and we
1758 * can't offline node now.
1763 if (stop_machine(check_and_unmap_cpu_on_node, pgdat, NULL))
1767 * all memory/cpu of this node are removed, we can offline this
1770 node_set_offline(nid);
1771 unregister_one_node(nid);
1773 if (!PageSlab(pgdat_page) && !PageCompound(pgdat_page))
1774 /* node data is allocated from boot memory */
1777 /* free waittable in each zone */
1778 for (i = 0; i < MAX_NR_ZONES; i++) {
1779 struct zone *zone = pgdat->node_zones + i;
1781 if (zone->wait_table)
1782 vfree(zone->wait_table);
1786 * Since there is no way to guarentee the address of pgdat/zone is not
1787 * on stack of any kernel threads or used by other kernel objects
1788 * without reference counting or other symchronizing method, do not
1789 * reset node_data and free pgdat here. Just reset it to 0 and reuse
1790 * the memory when the node is online again.
1792 memset(pgdat, 0, sizeof(*pgdat));
1794 EXPORT_SYMBOL(try_offline_node);
1796 int __ref remove_memory(int nid, u64 start, u64 size)
1798 unsigned long start_pfn, end_pfn;
1802 start_pfn = PFN_DOWN(start);
1803 end_pfn = start_pfn + PFN_DOWN(size);
1806 * When CONFIG_MEMCG is on, one memory block may be used by other
1807 * blocks to store page cgroup when onlining pages. But we don't know
1808 * in what order pages are onlined. So we iterate twice to offline
1810 * 1st iterate: offline every non primary memory block.
1811 * 2nd iterate: offline primary (i.e. first added) memory block.
1814 walk_memory_range(start_pfn, end_pfn, &ret,
1815 offline_memory_block_cb);
1825 lock_memory_hotplug();
1828 * we have offlined all memory blocks like this:
1829 * 1. lock memory hotplug
1830 * 2. offline a memory block
1831 * 3. unlock memory hotplug
1833 * repeat step1-3 to offline the memory block. All memory blocks
1834 * must be offlined before removing memory. But we don't hold the
1835 * lock in the whole operation. So we should check whether all
1836 * memory blocks are offlined.
1839 ret = walk_memory_range(start_pfn, end_pfn, NULL,
1840 is_memblock_offlined_cb);
1842 unlock_memory_hotplug();
1846 /* remove memmap entry */
1847 firmware_map_remove(start, start + size, "System RAM");
1849 arch_remove_memory(start, size);
1851 try_offline_node(nid);
1853 unlock_memory_hotplug();
1858 int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
1862 int remove_memory(int nid, u64 start, u64 size)
1866 #endif /* CONFIG_MEMORY_HOTREMOVE */
1867 EXPORT_SYMBOL_GPL(remove_memory);