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/bootmem.h>
37 #include <linux/compaction.h>
39 #include <asm/tlbflush.h>
44 * online_page_callback contains pointer to current page onlining function.
45 * Initially it is generic_online_page(). If it is required it could be
46 * changed by calling set_online_page_callback() for callback registration
47 * and restore_online_page_callback() for generic callback restore.
50 static void generic_online_page(struct page *page);
52 static online_page_callback_t online_page_callback = generic_online_page;
53 static DEFINE_MUTEX(online_page_callback_lock);
55 /* The same as the cpu_hotplug lock, but for memory hotplug. */
57 struct task_struct *active_writer;
58 struct mutex lock; /* Synchronizes accesses to refcount, */
60 * Also blocks the new readers during
61 * an ongoing mem hotplug operation.
65 #ifdef CONFIG_DEBUG_LOCK_ALLOC
66 struct lockdep_map dep_map;
69 .active_writer = NULL,
70 .lock = __MUTEX_INITIALIZER(mem_hotplug.lock),
72 #ifdef CONFIG_DEBUG_LOCK_ALLOC
73 .dep_map = {.name = "mem_hotplug.lock" },
77 /* Lockdep annotations for get/put_online_mems() and mem_hotplug_begin/end() */
78 #define memhp_lock_acquire_read() lock_map_acquire_read(&mem_hotplug.dep_map)
79 #define memhp_lock_acquire() lock_map_acquire(&mem_hotplug.dep_map)
80 #define memhp_lock_release() lock_map_release(&mem_hotplug.dep_map)
82 bool movable_node_enabled = false;
84 #ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE
85 bool memhp_auto_online;
87 bool memhp_auto_online = true;
89 EXPORT_SYMBOL_GPL(memhp_auto_online);
91 static int __init setup_memhp_default_state(char *str)
93 if (!strcmp(str, "online"))
94 memhp_auto_online = true;
95 else if (!strcmp(str, "offline"))
96 memhp_auto_online = false;
100 __setup("memhp_default_state=", setup_memhp_default_state);
102 void get_online_mems(void)
105 if (mem_hotplug.active_writer == current)
107 memhp_lock_acquire_read();
108 mutex_lock(&mem_hotplug.lock);
109 mem_hotplug.refcount++;
110 mutex_unlock(&mem_hotplug.lock);
114 void put_online_mems(void)
116 if (mem_hotplug.active_writer == current)
118 mutex_lock(&mem_hotplug.lock);
120 if (WARN_ON(!mem_hotplug.refcount))
121 mem_hotplug.refcount++; /* try to fix things up */
123 if (!--mem_hotplug.refcount && unlikely(mem_hotplug.active_writer))
124 wake_up_process(mem_hotplug.active_writer);
125 mutex_unlock(&mem_hotplug.lock);
126 memhp_lock_release();
130 /* Serializes write accesses to mem_hotplug.active_writer. */
131 static DEFINE_MUTEX(memory_add_remove_lock);
133 void mem_hotplug_begin(void)
135 mutex_lock(&memory_add_remove_lock);
137 mem_hotplug.active_writer = current;
139 memhp_lock_acquire();
141 mutex_lock(&mem_hotplug.lock);
142 if (likely(!mem_hotplug.refcount))
144 __set_current_state(TASK_UNINTERRUPTIBLE);
145 mutex_unlock(&mem_hotplug.lock);
150 void mem_hotplug_done(void)
152 mem_hotplug.active_writer = NULL;
153 mutex_unlock(&mem_hotplug.lock);
154 memhp_lock_release();
155 mutex_unlock(&memory_add_remove_lock);
158 /* add this memory to iomem resource */
159 static struct resource *register_memory_resource(u64 start, u64 size)
161 struct resource *res;
162 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
164 return ERR_PTR(-ENOMEM);
166 res->name = "System RAM";
168 res->end = start + size - 1;
169 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
170 if (request_resource(&iomem_resource, res) < 0) {
171 pr_debug("System RAM resource %pR cannot be added\n", res);
173 return ERR_PTR(-EEXIST);
178 static void release_memory_resource(struct resource *res)
182 release_resource(res);
187 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
188 void get_page_bootmem(unsigned long info, struct page *page,
191 page->freelist = (void *)type;
192 SetPagePrivate(page);
193 set_page_private(page, info);
197 void put_page_bootmem(struct page *page)
201 type = (unsigned long) page->freelist;
202 BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
203 type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE);
205 if (page_ref_dec_return(page) == 1) {
206 page->freelist = NULL;
207 ClearPagePrivate(page);
208 set_page_private(page, 0);
209 INIT_LIST_HEAD(&page->lru);
210 free_reserved_page(page);
214 #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
215 #ifndef CONFIG_SPARSEMEM_VMEMMAP
216 static void register_page_bootmem_info_section(unsigned long start_pfn)
218 unsigned long *usemap, mapsize, section_nr, i;
219 struct mem_section *ms;
220 struct page *page, *memmap;
222 section_nr = pfn_to_section_nr(start_pfn);
223 ms = __nr_to_section(section_nr);
225 /* Get section's memmap address */
226 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
229 * Get page for the memmap's phys address
230 * XXX: need more consideration for sparse_vmemmap...
232 page = virt_to_page(memmap);
233 mapsize = sizeof(struct page) * PAGES_PER_SECTION;
234 mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT;
236 /* remember memmap's page */
237 for (i = 0; i < mapsize; i++, page++)
238 get_page_bootmem(section_nr, page, SECTION_INFO);
240 usemap = __nr_to_section(section_nr)->pageblock_flags;
241 page = virt_to_page(usemap);
243 mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT;
245 for (i = 0; i < mapsize; i++, page++)
246 get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
249 #else /* CONFIG_SPARSEMEM_VMEMMAP */
250 static void register_page_bootmem_info_section(unsigned long start_pfn)
252 unsigned long *usemap, mapsize, section_nr, i;
253 struct mem_section *ms;
254 struct page *page, *memmap;
256 if (!pfn_valid(start_pfn))
259 section_nr = pfn_to_section_nr(start_pfn);
260 ms = __nr_to_section(section_nr);
262 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
264 register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION);
266 usemap = __nr_to_section(section_nr)->pageblock_flags;
267 page = virt_to_page(usemap);
269 mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT;
271 for (i = 0; i < mapsize; i++, page++)
272 get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
274 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
276 void __init register_page_bootmem_info_node(struct pglist_data *pgdat)
278 unsigned long i, pfn, end_pfn, nr_pages;
279 int node = pgdat->node_id;
282 nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT;
283 page = virt_to_page(pgdat);
285 for (i = 0; i < nr_pages; i++, page++)
286 get_page_bootmem(node, page, NODE_INFO);
288 pfn = pgdat->node_start_pfn;
289 end_pfn = pgdat_end_pfn(pgdat);
291 /* register section info */
292 for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
294 * Some platforms can assign the same pfn to multiple nodes - on
295 * node0 as well as nodeN. To avoid registering a pfn against
296 * multiple nodes we check that this pfn does not already
297 * reside in some other nodes.
299 if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node))
300 register_page_bootmem_info_section(pfn);
303 #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */
305 static int __meminit __add_section(int nid, unsigned long phys_start_pfn,
311 if (pfn_valid(phys_start_pfn))
314 ret = sparse_add_one_section(NODE_DATA(nid), phys_start_pfn);
319 * Make all the pages reserved so that nobody will stumble over half
321 * FIXME: We also have to associate it with a node because pfn_to_node
322 * relies on having page with the proper node.
324 for (i = 0; i < PAGES_PER_SECTION; i++) {
325 unsigned long pfn = phys_start_pfn + i;
330 page = pfn_to_page(pfn);
331 set_page_node(page, nid);
332 SetPageReserved(page);
338 return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
342 * Reasonably generic function for adding memory. It is
343 * expected that archs that support memory hotplug will
344 * call this function after deciding the zone to which to
347 int __ref __add_pages(int nid, unsigned long phys_start_pfn,
348 unsigned long nr_pages, bool want_memblock)
352 int start_sec, end_sec;
353 struct vmem_altmap *altmap;
355 /* during initialize mem_map, align hot-added range to section */
356 start_sec = pfn_to_section_nr(phys_start_pfn);
357 end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
359 altmap = to_vmem_altmap((unsigned long) pfn_to_page(phys_start_pfn));
362 * Validate altmap is within bounds of the total request
364 if (altmap->base_pfn != phys_start_pfn
365 || vmem_altmap_offset(altmap) > nr_pages) {
366 pr_warn_once("memory add fail, invalid altmap\n");
373 for (i = start_sec; i <= end_sec; i++) {
374 err = __add_section(nid, section_nr_to_pfn(i), want_memblock);
377 * EEXIST is finally dealt with by ioresource collision
378 * check. see add_memory() => register_memory_resource()
379 * Warning will be printed if there is collision.
381 if (err && (err != -EEXIST))
385 vmemmap_populate_print_last();
389 EXPORT_SYMBOL_GPL(__add_pages);
391 #ifdef CONFIG_MEMORY_HOTREMOVE
392 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */
393 static int find_smallest_section_pfn(int nid, struct zone *zone,
394 unsigned long start_pfn,
395 unsigned long end_pfn)
397 struct mem_section *ms;
399 for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SECTION) {
400 ms = __pfn_to_section(start_pfn);
402 if (unlikely(!valid_section(ms)))
405 if (unlikely(pfn_to_nid(start_pfn) != nid))
408 if (zone && zone != page_zone(pfn_to_page(start_pfn)))
417 /* find the biggest valid pfn in the range [start_pfn, end_pfn). */
418 static int find_biggest_section_pfn(int nid, struct zone *zone,
419 unsigned long start_pfn,
420 unsigned long end_pfn)
422 struct mem_section *ms;
425 /* pfn is the end pfn of a memory section. */
427 for (; pfn >= start_pfn; pfn -= PAGES_PER_SECTION) {
428 ms = __pfn_to_section(pfn);
430 if (unlikely(!valid_section(ms)))
433 if (unlikely(pfn_to_nid(pfn) != nid))
436 if (zone && zone != page_zone(pfn_to_page(pfn)))
445 static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
446 unsigned long end_pfn)
448 unsigned long zone_start_pfn = zone->zone_start_pfn;
449 unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */
450 unsigned long zone_end_pfn = z;
452 struct mem_section *ms;
453 int nid = zone_to_nid(zone);
455 zone_span_writelock(zone);
456 if (zone_start_pfn == start_pfn) {
458 * If the section is smallest section in the zone, it need
459 * shrink zone->zone_start_pfn and zone->zone_spanned_pages.
460 * In this case, we find second smallest valid mem_section
461 * for shrinking zone.
463 pfn = find_smallest_section_pfn(nid, zone, end_pfn,
466 zone->zone_start_pfn = pfn;
467 zone->spanned_pages = zone_end_pfn - pfn;
469 } else if (zone_end_pfn == end_pfn) {
471 * If the section is biggest section in the zone, it need
472 * shrink zone->spanned_pages.
473 * In this case, we find second biggest valid mem_section for
476 pfn = find_biggest_section_pfn(nid, zone, zone_start_pfn,
479 zone->spanned_pages = pfn - zone_start_pfn + 1;
483 * The section is not biggest or smallest mem_section in the zone, it
484 * only creates a hole in the zone. So in this case, we need not
485 * change the zone. But perhaps, the zone has only hole data. Thus
486 * it check the zone has only hole or not.
488 pfn = zone_start_pfn;
489 for (; pfn < zone_end_pfn; pfn += PAGES_PER_SECTION) {
490 ms = __pfn_to_section(pfn);
492 if (unlikely(!valid_section(ms)))
495 if (page_zone(pfn_to_page(pfn)) != zone)
498 /* If the section is current section, it continues the loop */
499 if (start_pfn == pfn)
502 /* If we find valid section, we have nothing to do */
503 zone_span_writeunlock(zone);
507 /* The zone has no valid section */
508 zone->zone_start_pfn = 0;
509 zone->spanned_pages = 0;
510 zone_span_writeunlock(zone);
513 static void shrink_pgdat_span(struct pglist_data *pgdat,
514 unsigned long start_pfn, unsigned long end_pfn)
516 unsigned long pgdat_start_pfn = pgdat->node_start_pfn;
517 unsigned long p = pgdat_end_pfn(pgdat); /* pgdat_end_pfn namespace clash */
518 unsigned long pgdat_end_pfn = p;
520 struct mem_section *ms;
521 int nid = pgdat->node_id;
523 if (pgdat_start_pfn == start_pfn) {
525 * If the section is smallest section in the pgdat, it need
526 * shrink pgdat->node_start_pfn and pgdat->node_spanned_pages.
527 * In this case, we find second smallest valid mem_section
528 * for shrinking zone.
530 pfn = find_smallest_section_pfn(nid, NULL, end_pfn,
533 pgdat->node_start_pfn = pfn;
534 pgdat->node_spanned_pages = pgdat_end_pfn - pfn;
536 } else if (pgdat_end_pfn == end_pfn) {
538 * If the section is biggest section in the pgdat, it need
539 * shrink pgdat->node_spanned_pages.
540 * In this case, we find second biggest valid mem_section for
543 pfn = find_biggest_section_pfn(nid, NULL, pgdat_start_pfn,
546 pgdat->node_spanned_pages = pfn - pgdat_start_pfn + 1;
550 * If the section is not biggest or smallest mem_section in the pgdat,
551 * it only creates a hole in the pgdat. So in this case, we need not
553 * But perhaps, the pgdat has only hole data. Thus it check the pgdat
554 * has only hole or not.
556 pfn = pgdat_start_pfn;
557 for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SECTION) {
558 ms = __pfn_to_section(pfn);
560 if (unlikely(!valid_section(ms)))
563 if (pfn_to_nid(pfn) != nid)
566 /* If the section is current section, it continues the loop */
567 if (start_pfn == pfn)
570 /* If we find valid section, we have nothing to do */
574 /* The pgdat has no valid section */
575 pgdat->node_start_pfn = 0;
576 pgdat->node_spanned_pages = 0;
579 static void __remove_zone(struct zone *zone, unsigned long start_pfn)
581 struct pglist_data *pgdat = zone->zone_pgdat;
582 int nr_pages = PAGES_PER_SECTION;
586 zone_type = zone - pgdat->node_zones;
588 pgdat_resize_lock(zone->zone_pgdat, &flags);
589 shrink_zone_span(zone, start_pfn, start_pfn + nr_pages);
590 shrink_pgdat_span(pgdat, start_pfn, start_pfn + nr_pages);
591 pgdat_resize_unlock(zone->zone_pgdat, &flags);
594 static int __remove_section(struct zone *zone, struct mem_section *ms,
595 unsigned long map_offset)
597 unsigned long start_pfn;
601 if (!valid_section(ms))
604 ret = unregister_memory_section(ms);
608 scn_nr = __section_nr(ms);
609 start_pfn = section_nr_to_pfn(scn_nr);
610 __remove_zone(zone, start_pfn);
612 sparse_remove_one_section(zone, ms, map_offset);
617 * __remove_pages() - remove sections of pages from a zone
618 * @zone: zone from which pages need to be removed
619 * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
620 * @nr_pages: number of pages to remove (must be multiple of section size)
622 * Generic helper function to remove section mappings and sysfs entries
623 * for the section of the memory we are removing. Caller needs to make
624 * sure that pages are marked reserved and zones are adjust properly by
625 * calling offline_pages().
627 int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
628 unsigned long nr_pages)
631 unsigned long map_offset = 0;
632 int sections_to_remove, ret = 0;
634 /* In the ZONE_DEVICE case device driver owns the memory region */
635 if (is_dev_zone(zone)) {
636 struct page *page = pfn_to_page(phys_start_pfn);
637 struct vmem_altmap *altmap;
639 altmap = to_vmem_altmap((unsigned long) page);
641 map_offset = vmem_altmap_offset(altmap);
643 resource_size_t start, size;
645 start = phys_start_pfn << PAGE_SHIFT;
646 size = nr_pages * PAGE_SIZE;
648 ret = release_mem_region_adjustable(&iomem_resource, start,
651 resource_size_t endres = start + size - 1;
653 pr_warn("Unable to release resource <%pa-%pa> (%d)\n",
654 &start, &endres, ret);
658 clear_zone_contiguous(zone);
661 * We can only remove entire sections
663 BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK);
664 BUG_ON(nr_pages % PAGES_PER_SECTION);
666 sections_to_remove = nr_pages / PAGES_PER_SECTION;
667 for (i = 0; i < sections_to_remove; i++) {
668 unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
670 ret = __remove_section(zone, __pfn_to_section(pfn), map_offset);
676 set_zone_contiguous(zone);
680 #endif /* CONFIG_MEMORY_HOTREMOVE */
682 int set_online_page_callback(online_page_callback_t callback)
687 mutex_lock(&online_page_callback_lock);
689 if (online_page_callback == generic_online_page) {
690 online_page_callback = callback;
694 mutex_unlock(&online_page_callback_lock);
699 EXPORT_SYMBOL_GPL(set_online_page_callback);
701 int restore_online_page_callback(online_page_callback_t callback)
706 mutex_lock(&online_page_callback_lock);
708 if (online_page_callback == callback) {
709 online_page_callback = generic_online_page;
713 mutex_unlock(&online_page_callback_lock);
718 EXPORT_SYMBOL_GPL(restore_online_page_callback);
720 void __online_page_set_limits(struct page *page)
723 EXPORT_SYMBOL_GPL(__online_page_set_limits);
725 void __online_page_increment_counters(struct page *page)
727 adjust_managed_page_count(page, 1);
729 EXPORT_SYMBOL_GPL(__online_page_increment_counters);
731 void __online_page_free(struct page *page)
733 __free_reserved_page(page);
735 EXPORT_SYMBOL_GPL(__online_page_free);
737 static void generic_online_page(struct page *page)
739 __online_page_set_limits(page);
740 __online_page_increment_counters(page);
741 __online_page_free(page);
744 static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
748 unsigned long onlined_pages = *(unsigned long *)arg;
751 if (PageReserved(pfn_to_page(start_pfn)))
752 for (i = 0; i < nr_pages; i++) {
753 page = pfn_to_page(start_pfn + i);
754 (*online_page_callback)(page);
758 online_mem_sections(start_pfn, start_pfn + nr_pages);
760 *(unsigned long *)arg = onlined_pages;
764 /* check which state of node_states will be changed when online memory */
765 static void node_states_check_changes_online(unsigned long nr_pages,
766 struct zone *zone, struct memory_notify *arg)
768 int nid = zone_to_nid(zone);
769 enum zone_type zone_last = ZONE_NORMAL;
772 * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
773 * contains nodes which have zones of 0...ZONE_NORMAL,
774 * set zone_last to ZONE_NORMAL.
776 * If we don't have HIGHMEM nor movable node,
777 * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
778 * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
780 if (N_MEMORY == N_NORMAL_MEMORY)
781 zone_last = ZONE_MOVABLE;
784 * if the memory to be online is in a zone of 0...zone_last, and
785 * the zones of 0...zone_last don't have memory before online, we will
786 * need to set the node to node_states[N_NORMAL_MEMORY] after
787 * the memory is online.
789 if (zone_idx(zone) <= zone_last && !node_state(nid, N_NORMAL_MEMORY))
790 arg->status_change_nid_normal = nid;
792 arg->status_change_nid_normal = -1;
794 #ifdef CONFIG_HIGHMEM
796 * If we have movable node, node_states[N_HIGH_MEMORY]
797 * contains nodes which have zones of 0...ZONE_HIGHMEM,
798 * set zone_last to ZONE_HIGHMEM.
800 * If we don't have movable node, node_states[N_NORMAL_MEMORY]
801 * contains nodes which have zones of 0...ZONE_MOVABLE,
802 * set zone_last to ZONE_MOVABLE.
804 zone_last = ZONE_HIGHMEM;
805 if (N_MEMORY == N_HIGH_MEMORY)
806 zone_last = ZONE_MOVABLE;
808 if (zone_idx(zone) <= zone_last && !node_state(nid, N_HIGH_MEMORY))
809 arg->status_change_nid_high = nid;
811 arg->status_change_nid_high = -1;
813 arg->status_change_nid_high = arg->status_change_nid_normal;
817 * if the node don't have memory befor online, we will need to
818 * set the node to node_states[N_MEMORY] after the memory
821 if (!node_state(nid, N_MEMORY))
822 arg->status_change_nid = nid;
824 arg->status_change_nid = -1;
827 static void node_states_set_node(int node, struct memory_notify *arg)
829 if (arg->status_change_nid_normal >= 0)
830 node_set_state(node, N_NORMAL_MEMORY);
832 if (arg->status_change_nid_high >= 0)
833 node_set_state(node, N_HIGH_MEMORY);
835 node_set_state(node, N_MEMORY);
838 bool allow_online_pfn_range(int nid, unsigned long pfn, unsigned long nr_pages, int online_type)
840 struct pglist_data *pgdat = NODE_DATA(nid);
841 struct zone *movable_zone = &pgdat->node_zones[ZONE_MOVABLE];
842 struct zone *default_zone = default_zone_for_pfn(nid, pfn, nr_pages);
845 * TODO there shouldn't be any inherent reason to have ZONE_NORMAL
846 * physically before ZONE_MOVABLE. All we need is they do not
847 * overlap. Historically we didn't allow ZONE_NORMAL after ZONE_MOVABLE
848 * though so let's stick with it for simplicity for now.
849 * TODO make sure we do not overlap with ZONE_DEVICE
851 if (online_type == MMOP_ONLINE_KERNEL) {
852 if (zone_is_empty(movable_zone))
854 return movable_zone->zone_start_pfn >= pfn + nr_pages;
855 } else if (online_type == MMOP_ONLINE_MOVABLE) {
856 return zone_end_pfn(default_zone) <= pfn;
859 /* MMOP_ONLINE_KEEP will always succeed and inherits the current zone */
860 return online_type == MMOP_ONLINE_KEEP;
863 static void __meminit resize_zone_range(struct zone *zone, unsigned long start_pfn,
864 unsigned long nr_pages)
866 unsigned long old_end_pfn = zone_end_pfn(zone);
868 if (zone_is_empty(zone) || start_pfn < zone->zone_start_pfn)
869 zone->zone_start_pfn = start_pfn;
871 zone->spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - zone->zone_start_pfn;
874 static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned long start_pfn,
875 unsigned long nr_pages)
877 unsigned long old_end_pfn = pgdat_end_pfn(pgdat);
879 if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn)
880 pgdat->node_start_pfn = start_pfn;
882 pgdat->node_spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - pgdat->node_start_pfn;
885 void __ref move_pfn_range_to_zone(struct zone *zone,
886 unsigned long start_pfn, unsigned long nr_pages)
888 struct pglist_data *pgdat = zone->zone_pgdat;
889 int nid = pgdat->node_id;
892 if (zone_is_empty(zone))
893 init_currently_empty_zone(zone, start_pfn, nr_pages);
895 clear_zone_contiguous(zone);
897 /* TODO Huh pgdat is irqsave while zone is not. It used to be like that before */
898 pgdat_resize_lock(pgdat, &flags);
899 zone_span_writelock(zone);
900 resize_zone_range(zone, start_pfn, nr_pages);
901 zone_span_writeunlock(zone);
902 resize_pgdat_range(pgdat, start_pfn, nr_pages);
903 pgdat_resize_unlock(pgdat, &flags);
906 * TODO now we have a visible range of pages which are not associated
907 * with their zone properly. Not nice but set_pfnblock_flags_mask
908 * expects the zone spans the pfn range. All the pages in the range
909 * are reserved so nobody should be touching them so we should be safe
911 memmap_init_zone(nr_pages, nid, zone_idx(zone), start_pfn, MEMMAP_HOTPLUG);
913 set_zone_contiguous(zone);
917 * Returns a default kernel memory zone for the given pfn range.
918 * If no kernel zone covers this pfn range it will automatically go
919 * to the ZONE_NORMAL.
921 struct zone *default_zone_for_pfn(int nid, unsigned long start_pfn,
922 unsigned long nr_pages)
924 struct pglist_data *pgdat = NODE_DATA(nid);
927 for (zid = 0; zid <= ZONE_NORMAL; zid++) {
928 struct zone *zone = &pgdat->node_zones[zid];
930 if (zone_intersects(zone, start_pfn, nr_pages))
934 return &pgdat->node_zones[ZONE_NORMAL];
938 * Associates the given pfn range with the given node and the zone appropriate
939 * for the given online type.
941 static struct zone * __meminit move_pfn_range(int online_type, int nid,
942 unsigned long start_pfn, unsigned long nr_pages)
944 struct pglist_data *pgdat = NODE_DATA(nid);
945 struct zone *zone = default_zone_for_pfn(nid, start_pfn, nr_pages);
947 if (online_type == MMOP_ONLINE_KEEP) {
948 struct zone *movable_zone = &pgdat->node_zones[ZONE_MOVABLE];
950 * MMOP_ONLINE_KEEP defaults to MMOP_ONLINE_KERNEL but use
951 * movable zone if that is not possible (e.g. we are within
952 * or past the existing movable zone)
954 if (!allow_online_pfn_range(nid, start_pfn, nr_pages,
957 } else if (online_type == MMOP_ONLINE_MOVABLE) {
958 zone = &pgdat->node_zones[ZONE_MOVABLE];
961 move_pfn_range_to_zone(zone, start_pfn, nr_pages);
965 /* Must be protected by mem_hotplug_begin() */
966 int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type)
969 unsigned long onlined_pages = 0;
971 int need_zonelists_rebuild = 0;
974 struct memory_notify arg;
976 nid = pfn_to_nid(pfn);
977 if (!allow_online_pfn_range(nid, pfn, nr_pages, online_type))
980 /* associate pfn range with the zone */
981 zone = move_pfn_range(online_type, nid, pfn, nr_pages);
984 arg.nr_pages = nr_pages;
985 node_states_check_changes_online(nr_pages, zone, &arg);
987 ret = memory_notify(MEM_GOING_ONLINE, &arg);
988 ret = notifier_to_errno(ret);
990 goto failed_addition;
993 * If this zone is not populated, then it is not in zonelist.
994 * This means the page allocator ignores this zone.
995 * So, zonelist must be updated after online.
997 mutex_lock(&zonelists_mutex);
998 if (!populated_zone(zone)) {
999 need_zonelists_rebuild = 1;
1000 build_all_zonelists(NULL, zone);
1003 ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages,
1004 online_pages_range);
1006 if (need_zonelists_rebuild)
1007 zone_pcp_reset(zone);
1008 mutex_unlock(&zonelists_mutex);
1009 goto failed_addition;
1012 zone->present_pages += onlined_pages;
1014 pgdat_resize_lock(zone->zone_pgdat, &flags);
1015 zone->zone_pgdat->node_present_pages += onlined_pages;
1016 pgdat_resize_unlock(zone->zone_pgdat, &flags);
1018 if (onlined_pages) {
1019 node_states_set_node(nid, &arg);
1020 if (need_zonelists_rebuild)
1021 build_all_zonelists(NULL, NULL);
1023 zone_pcp_update(zone);
1026 mutex_unlock(&zonelists_mutex);
1028 init_per_zone_wmark_min();
1030 if (onlined_pages) {
1035 vm_total_pages = nr_free_pagecache_pages();
1037 writeback_set_ratelimit();
1040 memory_notify(MEM_ONLINE, &arg);
1044 pr_debug("online_pages [mem %#010llx-%#010llx] failed\n",
1045 (unsigned long long) pfn << PAGE_SHIFT,
1046 (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1);
1047 memory_notify(MEM_CANCEL_ONLINE, &arg);
1050 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
1052 static void reset_node_present_pages(pg_data_t *pgdat)
1056 for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
1057 z->present_pages = 0;
1059 pgdat->node_present_pages = 0;
1062 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
1063 static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
1065 struct pglist_data *pgdat;
1066 unsigned long zones_size[MAX_NR_ZONES] = {0};
1067 unsigned long zholes_size[MAX_NR_ZONES] = {0};
1068 unsigned long start_pfn = PFN_DOWN(start);
1070 pgdat = NODE_DATA(nid);
1072 pgdat = arch_alloc_nodedata(nid);
1076 arch_refresh_nodedata(nid, pgdat);
1079 * Reset the nr_zones, order and classzone_idx before reuse.
1080 * Note that kswapd will init kswapd_classzone_idx properly
1081 * when it starts in the near future.
1083 pgdat->nr_zones = 0;
1084 pgdat->kswapd_order = 0;
1085 pgdat->kswapd_classzone_idx = 0;
1088 /* we can use NODE_DATA(nid) from here */
1090 /* init node's zones as empty zones, we don't have any present pages.*/
1091 free_area_init_node(nid, zones_size, start_pfn, zholes_size);
1092 pgdat->per_cpu_nodestats = alloc_percpu(struct per_cpu_nodestat);
1095 * The node we allocated has no zone fallback lists. For avoiding
1096 * to access not-initialized zonelist, build here.
1098 mutex_lock(&zonelists_mutex);
1099 build_all_zonelists(pgdat, NULL);
1100 mutex_unlock(&zonelists_mutex);
1103 * zone->managed_pages is set to an approximate value in
1104 * free_area_init_core(), which will cause
1105 * /sys/device/system/node/nodeX/meminfo has wrong data.
1106 * So reset it to 0 before any memory is onlined.
1108 reset_node_managed_pages(pgdat);
1111 * When memory is hot-added, all the memory is in offline state. So
1112 * clear all zones' present_pages because they will be updated in
1113 * online_pages() and offline_pages().
1115 reset_node_present_pages(pgdat);
1120 static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
1122 arch_refresh_nodedata(nid, NULL);
1123 free_percpu(pgdat->per_cpu_nodestats);
1124 arch_free_nodedata(pgdat);
1130 * try_online_node - online a node if offlined
1132 * called by cpu_up() to online a node without onlined memory.
1134 int try_online_node(int nid)
1139 if (node_online(nid))
1142 mem_hotplug_begin();
1143 pgdat = hotadd_new_pgdat(nid, 0);
1145 pr_err("Cannot online node %d due to NULL pgdat\n", nid);
1149 node_set_online(nid);
1150 ret = register_one_node(nid);
1153 if (pgdat->node_zonelists->_zonerefs->zone == NULL) {
1154 mutex_lock(&zonelists_mutex);
1155 build_all_zonelists(NULL, NULL);
1156 mutex_unlock(&zonelists_mutex);
1164 static int check_hotplug_memory_range(u64 start, u64 size)
1166 u64 start_pfn = PFN_DOWN(start);
1167 u64 nr_pages = size >> PAGE_SHIFT;
1169 /* Memory range must be aligned with section */
1170 if ((start_pfn & ~PAGE_SECTION_MASK) ||
1171 (nr_pages % PAGES_PER_SECTION) || (!nr_pages)) {
1172 pr_err("Section-unaligned hotplug range: start 0x%llx, size 0x%llx\n",
1173 (unsigned long long)start,
1174 (unsigned long long)size);
1181 static int online_memory_block(struct memory_block *mem, void *arg)
1183 return device_online(&mem->dev);
1186 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
1187 int __ref add_memory_resource(int nid, struct resource *res, bool online)
1190 pg_data_t *pgdat = NULL;
1196 size = resource_size(res);
1198 ret = check_hotplug_memory_range(start, size);
1202 { /* Stupid hack to suppress address-never-null warning */
1203 void *p = NODE_DATA(nid);
1207 mem_hotplug_begin();
1210 * Add new range to memblock so that when hotadd_new_pgdat() is called
1211 * to allocate new pgdat, get_pfn_range_for_nid() will be able to find
1212 * this new range and calculate total pages correctly. The range will
1213 * be removed at hot-remove time.
1215 memblock_add_node(start, size, nid);
1217 new_node = !node_online(nid);
1219 pgdat = hotadd_new_pgdat(nid, start);
1225 /* call arch's memory hotadd */
1226 ret = arch_add_memory(nid, start, size, true);
1231 /* we online node here. we can't roll back from here. */
1232 node_set_online(nid);
1235 unsigned long start_pfn = start >> PAGE_SHIFT;
1236 unsigned long nr_pages = size >> PAGE_SHIFT;
1238 ret = __register_one_node(nid);
1243 * link memory sections under this node. This is already
1244 * done when creatig memory section in register_new_memory
1245 * but that depends to have the node registered so offline
1246 * nodes have to go through register_node.
1247 * TODO clean up this mess.
1249 ret = link_mem_sections(nid, start_pfn, nr_pages);
1252 * If sysfs file of new node can't create, cpu on the node
1253 * can't be hot-added. There is no rollback way now.
1254 * So, check by BUG_ON() to catch it reluctantly..
1259 /* create new memmap entry */
1260 firmware_map_add_hotplug(start, start + size, "System RAM");
1262 /* online pages if requested */
1264 walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1),
1265 NULL, online_memory_block);
1270 /* rollback pgdat allocation and others */
1272 rollback_node_hotadd(nid, pgdat);
1273 memblock_remove(start, size);
1279 EXPORT_SYMBOL_GPL(add_memory_resource);
1281 int __ref add_memory(int nid, u64 start, u64 size)
1283 struct resource *res;
1286 res = register_memory_resource(start, size);
1288 return PTR_ERR(res);
1290 ret = add_memory_resource(nid, res, memhp_auto_online);
1292 release_memory_resource(res);
1295 EXPORT_SYMBOL_GPL(add_memory);
1297 #ifdef CONFIG_MEMORY_HOTREMOVE
1299 * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
1300 * set and the size of the free page is given by page_order(). Using this,
1301 * the function determines if the pageblock contains only free pages.
1302 * Due to buddy contraints, a free page at least the size of a pageblock will
1303 * be located at the start of the pageblock
1305 static inline int pageblock_free(struct page *page)
1307 return PageBuddy(page) && page_order(page) >= pageblock_order;
1310 /* Return the start of the next active pageblock after a given page */
1311 static struct page *next_active_pageblock(struct page *page)
1313 /* Ensure the starting page is pageblock-aligned */
1314 BUG_ON(page_to_pfn(page) & (pageblock_nr_pages - 1));
1316 /* If the entire pageblock is free, move to the end of free page */
1317 if (pageblock_free(page)) {
1319 /* be careful. we don't have locks, page_order can be changed.*/
1320 order = page_order(page);
1321 if ((order < MAX_ORDER) && (order >= pageblock_order))
1322 return page + (1 << order);
1325 return page + pageblock_nr_pages;
1328 /* Checks if this range of memory is likely to be hot-removable. */
1329 bool is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages)
1331 struct page *page = pfn_to_page(start_pfn);
1332 struct page *end_page = page + nr_pages;
1334 /* Check the starting page of each pageblock within the range */
1335 for (; page < end_page; page = next_active_pageblock(page)) {
1336 if (!is_pageblock_removable_nolock(page))
1341 /* All pageblocks in the memory block are likely to be hot-removable */
1346 * Confirm all pages in a range [start, end) belong to the same zone.
1347 * When true, return its valid [start, end).
1349 int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn,
1350 unsigned long *valid_start, unsigned long *valid_end)
1352 unsigned long pfn, sec_end_pfn;
1353 unsigned long start, end;
1354 struct zone *zone = NULL;
1357 for (pfn = start_pfn, sec_end_pfn = SECTION_ALIGN_UP(start_pfn + 1);
1359 pfn = sec_end_pfn, sec_end_pfn += PAGES_PER_SECTION) {
1360 /* Make sure the memory section is present first */
1361 if (!present_section_nr(pfn_to_section_nr(pfn)))
1363 for (; pfn < sec_end_pfn && pfn < end_pfn;
1364 pfn += MAX_ORDER_NR_PAGES) {
1366 /* This is just a CONFIG_HOLES_IN_ZONE check.*/
1367 while ((i < MAX_ORDER_NR_PAGES) &&
1368 !pfn_valid_within(pfn + i))
1370 if (i == MAX_ORDER_NR_PAGES || pfn + i >= end_pfn)
1372 page = pfn_to_page(pfn + i);
1373 if (zone && page_zone(page) != zone)
1377 zone = page_zone(page);
1378 end = pfn + MAX_ORDER_NR_PAGES;
1383 *valid_start = start;
1384 *valid_end = min(end, end_pfn);
1392 * Scan pfn range [start,end) to find movable/migratable pages (LRU pages,
1393 * non-lru movable pages and hugepages). We scan pfn because it's much
1394 * easier than scanning over linked list. This function returns the pfn
1395 * of the first found movable page if it's found, otherwise 0.
1397 static unsigned long scan_movable_pages(unsigned long start, unsigned long end)
1401 for (pfn = start; pfn < end; pfn++) {
1402 if (pfn_valid(pfn)) {
1403 page = pfn_to_page(pfn);
1406 if (__PageMovable(page))
1408 if (PageHuge(page)) {
1409 if (page_huge_active(page))
1412 pfn = round_up(pfn + 1,
1413 1 << compound_order(page)) - 1;
1420 static struct page *new_node_page(struct page *page, unsigned long private,
1423 gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE;
1424 int nid = page_to_nid(page);
1425 nodemask_t nmask = node_states[N_MEMORY];
1426 struct page *new_page = NULL;
1429 * TODO: allocate a destination hugepage from a nearest neighbor node,
1430 * accordance with memory policy of the user process if possible. For
1431 * now as a simple work-around, we use the next node for destination.
1434 return alloc_huge_page_node(page_hstate(compound_head(page)),
1435 next_node_in(nid, nmask));
1437 node_clear(nid, nmask);
1439 if (PageHighMem(page)
1440 || (zone_idx(page_zone(page)) == ZONE_MOVABLE))
1441 gfp_mask |= __GFP_HIGHMEM;
1443 if (!nodes_empty(nmask))
1444 new_page = __alloc_pages_nodemask(gfp_mask, 0, nid, &nmask);
1446 new_page = __alloc_pages(gfp_mask, 0, nid);
1451 #define NR_OFFLINE_AT_ONCE_PAGES (256)
1453 do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
1457 int move_pages = NR_OFFLINE_AT_ONCE_PAGES;
1458 int not_managed = 0;
1462 for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) {
1463 if (!pfn_valid(pfn))
1465 page = pfn_to_page(pfn);
1467 if (PageHuge(page)) {
1468 struct page *head = compound_head(page);
1469 pfn = page_to_pfn(head) + (1<<compound_order(head)) - 1;
1470 if (compound_order(head) > PFN_SECTION_SHIFT) {
1474 if (isolate_huge_page(page, &source))
1475 move_pages -= 1 << compound_order(head);
1479 if (!get_page_unless_zero(page))
1482 * We can skip free pages. And we can deal with pages on
1483 * LRU and non-lru movable pages.
1486 ret = isolate_lru_page(page);
1488 ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE);
1489 if (!ret) { /* Success */
1491 list_add_tail(&page->lru, &source);
1493 if (!__PageMovable(page))
1494 inc_node_page_state(page, NR_ISOLATED_ANON +
1495 page_is_file_cache(page));
1498 #ifdef CONFIG_DEBUG_VM
1499 pr_alert("failed to isolate pfn %lx\n", pfn);
1500 dump_page(page, "isolation failed");
1503 /* Because we don't have big zone->lock. we should
1504 check this again here. */
1505 if (page_count(page)) {
1512 if (!list_empty(&source)) {
1514 putback_movable_pages(&source);
1518 /* Allocate a new page from the nearest neighbor node */
1519 ret = migrate_pages(&source, new_node_page, NULL, 0,
1520 MIGRATE_SYNC, MR_MEMORY_HOTPLUG);
1522 putback_movable_pages(&source);
1529 * remove from free_area[] and mark all as Reserved.
1532 offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
1535 __offline_isolated_pages(start, start + nr_pages);
1540 offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
1542 walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL,
1543 offline_isolated_pages_cb);
1547 * Check all pages in range, recoreded as memory resource, are isolated.
1550 check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
1554 long offlined = *(long *)data;
1555 ret = test_pages_isolated(start_pfn, start_pfn + nr_pages, true);
1556 offlined = nr_pages;
1558 *(long *)data += offlined;
1563 check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
1568 ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined,
1569 check_pages_isolated_cb);
1571 offlined = (long)ret;
1575 static int __init cmdline_parse_movable_node(char *p)
1577 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
1578 movable_node_enabled = true;
1580 pr_warn("movable_node parameter depends on CONFIG_HAVE_MEMBLOCK_NODE_MAP to work properly\n");
1584 early_param("movable_node", cmdline_parse_movable_node);
1586 /* check which state of node_states will be changed when offline memory */
1587 static void node_states_check_changes_offline(unsigned long nr_pages,
1588 struct zone *zone, struct memory_notify *arg)
1590 struct pglist_data *pgdat = zone->zone_pgdat;
1591 unsigned long present_pages = 0;
1592 enum zone_type zt, zone_last = ZONE_NORMAL;
1595 * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
1596 * contains nodes which have zones of 0...ZONE_NORMAL,
1597 * set zone_last to ZONE_NORMAL.
1599 * If we don't have HIGHMEM nor movable node,
1600 * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
1601 * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
1603 if (N_MEMORY == N_NORMAL_MEMORY)
1604 zone_last = ZONE_MOVABLE;
1607 * check whether node_states[N_NORMAL_MEMORY] will be changed.
1608 * If the memory to be offline is in a zone of 0...zone_last,
1609 * and it is the last present memory, 0...zone_last will
1610 * become empty after offline , thus we can determind we will
1611 * need to clear the node from node_states[N_NORMAL_MEMORY].
1613 for (zt = 0; zt <= zone_last; zt++)
1614 present_pages += pgdat->node_zones[zt].present_pages;
1615 if (zone_idx(zone) <= zone_last && nr_pages >= present_pages)
1616 arg->status_change_nid_normal = zone_to_nid(zone);
1618 arg->status_change_nid_normal = -1;
1620 #ifdef CONFIG_HIGHMEM
1622 * If we have movable node, node_states[N_HIGH_MEMORY]
1623 * contains nodes which have zones of 0...ZONE_HIGHMEM,
1624 * set zone_last to ZONE_HIGHMEM.
1626 * If we don't have movable node, node_states[N_NORMAL_MEMORY]
1627 * contains nodes which have zones of 0...ZONE_MOVABLE,
1628 * set zone_last to ZONE_MOVABLE.
1630 zone_last = ZONE_HIGHMEM;
1631 if (N_MEMORY == N_HIGH_MEMORY)
1632 zone_last = ZONE_MOVABLE;
1634 for (; zt <= zone_last; zt++)
1635 present_pages += pgdat->node_zones[zt].present_pages;
1636 if (zone_idx(zone) <= zone_last && nr_pages >= present_pages)
1637 arg->status_change_nid_high = zone_to_nid(zone);
1639 arg->status_change_nid_high = -1;
1641 arg->status_change_nid_high = arg->status_change_nid_normal;
1645 * node_states[N_HIGH_MEMORY] contains nodes which have 0...ZONE_MOVABLE
1647 zone_last = ZONE_MOVABLE;
1650 * check whether node_states[N_HIGH_MEMORY] will be changed
1651 * If we try to offline the last present @nr_pages from the node,
1652 * we can determind we will need to clear the node from
1653 * node_states[N_HIGH_MEMORY].
1655 for (; zt <= zone_last; zt++)
1656 present_pages += pgdat->node_zones[zt].present_pages;
1657 if (nr_pages >= present_pages)
1658 arg->status_change_nid = zone_to_nid(zone);
1660 arg->status_change_nid = -1;
1663 static void node_states_clear_node(int node, struct memory_notify *arg)
1665 if (arg->status_change_nid_normal >= 0)
1666 node_clear_state(node, N_NORMAL_MEMORY);
1668 if ((N_MEMORY != N_NORMAL_MEMORY) &&
1669 (arg->status_change_nid_high >= 0))
1670 node_clear_state(node, N_HIGH_MEMORY);
1672 if ((N_MEMORY != N_HIGH_MEMORY) &&
1673 (arg->status_change_nid >= 0))
1674 node_clear_state(node, N_MEMORY);
1677 static int __ref __offline_pages(unsigned long start_pfn,
1678 unsigned long end_pfn, unsigned long timeout)
1680 unsigned long pfn, nr_pages, expire;
1681 long offlined_pages;
1682 int ret, drain, retry_max, node;
1683 unsigned long flags;
1684 unsigned long valid_start, valid_end;
1686 struct memory_notify arg;
1688 /* at least, alignment against pageblock is necessary */
1689 if (!IS_ALIGNED(start_pfn, pageblock_nr_pages))
1691 if (!IS_ALIGNED(end_pfn, pageblock_nr_pages))
1693 /* This makes hotplug much easier...and readable.
1694 we assume this for now. .*/
1695 if (!test_pages_in_a_zone(start_pfn, end_pfn, &valid_start, &valid_end))
1698 zone = page_zone(pfn_to_page(valid_start));
1699 node = zone_to_nid(zone);
1700 nr_pages = end_pfn - start_pfn;
1702 /* set above range as isolated */
1703 ret = start_isolate_page_range(start_pfn, end_pfn,
1704 MIGRATE_MOVABLE, true);
1708 arg.start_pfn = start_pfn;
1709 arg.nr_pages = nr_pages;
1710 node_states_check_changes_offline(nr_pages, zone, &arg);
1712 ret = memory_notify(MEM_GOING_OFFLINE, &arg);
1713 ret = notifier_to_errno(ret);
1715 goto failed_removal;
1718 expire = jiffies + timeout;
1722 /* start memory hot removal */
1724 if (time_after(jiffies, expire))
1725 goto failed_removal;
1727 if (signal_pending(current))
1728 goto failed_removal;
1731 lru_add_drain_all();
1733 drain_all_pages(zone);
1736 pfn = scan_movable_pages(start_pfn, end_pfn);
1737 if (pfn) { /* We have movable pages */
1738 ret = do_migrate_range(pfn, end_pfn);
1744 if (--retry_max == 0)
1745 goto failed_removal;
1751 /* drain all zone's lru pagevec, this is asynchronous... */
1752 lru_add_drain_all();
1754 /* drain pcp pages, this is synchronous. */
1755 drain_all_pages(zone);
1757 * dissolve free hugepages in the memory block before doing offlining
1758 * actually in order to make hugetlbfs's object counting consistent.
1760 ret = dissolve_free_huge_pages(start_pfn, end_pfn);
1762 goto failed_removal;
1764 offlined_pages = check_pages_isolated(start_pfn, end_pfn);
1765 if (offlined_pages < 0) {
1767 goto failed_removal;
1769 pr_info("Offlined Pages %ld\n", offlined_pages);
1770 /* Ok, all of our target is isolated.
1771 We cannot do rollback at this point. */
1772 offline_isolated_pages(start_pfn, end_pfn);
1773 /* reset pagetype flags and makes migrate type to be MOVABLE */
1774 undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
1775 /* removal success */
1776 adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages);
1777 zone->present_pages -= offlined_pages;
1779 pgdat_resize_lock(zone->zone_pgdat, &flags);
1780 zone->zone_pgdat->node_present_pages -= offlined_pages;
1781 pgdat_resize_unlock(zone->zone_pgdat, &flags);
1783 init_per_zone_wmark_min();
1785 if (!populated_zone(zone)) {
1786 zone_pcp_reset(zone);
1787 mutex_lock(&zonelists_mutex);
1788 build_all_zonelists(NULL, NULL);
1789 mutex_unlock(&zonelists_mutex);
1791 zone_pcp_update(zone);
1793 node_states_clear_node(node, &arg);
1794 if (arg.status_change_nid >= 0) {
1796 kcompactd_stop(node);
1799 vm_total_pages = nr_free_pagecache_pages();
1800 writeback_set_ratelimit();
1802 memory_notify(MEM_OFFLINE, &arg);
1806 pr_debug("memory offlining [mem %#010llx-%#010llx] failed\n",
1807 (unsigned long long) start_pfn << PAGE_SHIFT,
1808 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1);
1809 memory_notify(MEM_CANCEL_OFFLINE, &arg);
1810 /* pushback to free area */
1811 undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
1815 /* Must be protected by mem_hotplug_begin() */
1816 int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
1818 return __offline_pages(start_pfn, start_pfn + nr_pages, 120 * HZ);
1820 #endif /* CONFIG_MEMORY_HOTREMOVE */
1823 * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn)
1824 * @start_pfn: start pfn of the memory range
1825 * @end_pfn: end pfn of the memory range
1826 * @arg: argument passed to func
1827 * @func: callback for each memory section walked
1829 * This function walks through all present mem sections in range
1830 * [start_pfn, end_pfn) and call func on each mem section.
1832 * Returns the return value of func.
1834 int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
1835 void *arg, int (*func)(struct memory_block *, void *))
1837 struct memory_block *mem = NULL;
1838 struct mem_section *section;
1839 unsigned long pfn, section_nr;
1842 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
1843 section_nr = pfn_to_section_nr(pfn);
1844 if (!present_section_nr(section_nr))
1847 section = __nr_to_section(section_nr);
1848 /* same memblock? */
1850 if ((section_nr >= mem->start_section_nr) &&
1851 (section_nr <= mem->end_section_nr))
1854 mem = find_memory_block_hinted(section, mem);
1858 ret = func(mem, arg);
1860 kobject_put(&mem->dev.kobj);
1866 kobject_put(&mem->dev.kobj);
1871 #ifdef CONFIG_MEMORY_HOTREMOVE
1872 static int check_memblock_offlined_cb(struct memory_block *mem, void *arg)
1874 int ret = !is_memblock_offlined(mem);
1876 if (unlikely(ret)) {
1877 phys_addr_t beginpa, endpa;
1879 beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr));
1880 endpa = PFN_PHYS(section_nr_to_pfn(mem->end_section_nr + 1))-1;
1881 pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n",
1888 static int check_cpu_on_node(pg_data_t *pgdat)
1892 for_each_present_cpu(cpu) {
1893 if (cpu_to_node(cpu) == pgdat->node_id)
1895 * the cpu on this node isn't removed, and we can't
1896 * offline this node.
1904 static void unmap_cpu_on_node(pg_data_t *pgdat)
1906 #ifdef CONFIG_ACPI_NUMA
1909 for_each_possible_cpu(cpu)
1910 if (cpu_to_node(cpu) == pgdat->node_id)
1911 numa_clear_node(cpu);
1915 static int check_and_unmap_cpu_on_node(pg_data_t *pgdat)
1919 ret = check_cpu_on_node(pgdat);
1924 * the node will be offlined when we come here, so we can clear
1925 * the cpu_to_node() now.
1928 unmap_cpu_on_node(pgdat);
1935 * Offline a node if all memory sections and cpus of the node are removed.
1937 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
1938 * and online/offline operations before this call.
1940 void try_offline_node(int nid)
1942 pg_data_t *pgdat = NODE_DATA(nid);
1943 unsigned long start_pfn = pgdat->node_start_pfn;
1944 unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages;
1947 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
1948 unsigned long section_nr = pfn_to_section_nr(pfn);
1950 if (!present_section_nr(section_nr))
1953 if (pfn_to_nid(pfn) != nid)
1957 * some memory sections of this node are not removed, and we
1958 * can't offline node now.
1963 if (check_and_unmap_cpu_on_node(pgdat))
1967 * all memory/cpu of this node are removed, we can offline this
1970 node_set_offline(nid);
1971 unregister_one_node(nid);
1973 EXPORT_SYMBOL(try_offline_node);
1978 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
1979 * and online/offline operations before this call, as required by
1980 * try_offline_node().
1982 void __ref remove_memory(int nid, u64 start, u64 size)
1986 BUG_ON(check_hotplug_memory_range(start, size));
1988 mem_hotplug_begin();
1991 * All memory blocks must be offlined before removing memory. Check
1992 * whether all memory blocks in question are offline and trigger a BUG()
1993 * if this is not the case.
1995 ret = walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), NULL,
1996 check_memblock_offlined_cb);
2000 /* remove memmap entry */
2001 firmware_map_remove(start, start + size, "System RAM");
2002 memblock_free(start, size);
2003 memblock_remove(start, size);
2005 arch_remove_memory(start, size);
2007 try_offline_node(nid);
2011 EXPORT_SYMBOL_GPL(remove_memory);
2012 #endif /* CONFIG_MEMORY_HOTREMOVE */