1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/mm/memory_hotplug.c
8 #include <linux/stddef.h>
10 #include <linux/sched/signal.h>
11 #include <linux/swap.h>
12 #include <linux/interrupt.h>
13 #include <linux/pagemap.h>
14 #include <linux/compiler.h>
15 #include <linux/export.h>
16 #include <linux/pagevec.h>
17 #include <linux/writeback.h>
18 #include <linux/slab.h>
19 #include <linux/sysctl.h>
20 #include <linux/cpu.h>
21 #include <linux/memory.h>
22 #include <linux/memremap.h>
23 #include <linux/memory_hotplug.h>
24 #include <linux/highmem.h>
25 #include <linux/vmalloc.h>
26 #include <linux/ioport.h>
27 #include <linux/delay.h>
28 #include <linux/migrate.h>
29 #include <linux/page-isolation.h>
30 #include <linux/pfn.h>
31 #include <linux/suspend.h>
32 #include <linux/mm_inline.h>
33 #include <linux/firmware-map.h>
34 #include <linux/stop_machine.h>
35 #include <linux/hugetlb.h>
36 #include <linux/memblock.h>
37 #include <linux/compaction.h>
38 #include <linux/rmap.h>
40 #include <asm/tlbflush.h>
46 * online_page_callback contains pointer to current page onlining function.
47 * Initially it is generic_online_page(). If it is required it could be
48 * changed by calling set_online_page_callback() for callback registration
49 * and restore_online_page_callback() for generic callback restore.
52 static online_page_callback_t online_page_callback
= generic_online_page
;
53 static DEFINE_MUTEX(online_page_callback_lock
);
55 DEFINE_STATIC_PERCPU_RWSEM(mem_hotplug_lock
);
57 void get_online_mems(void)
59 percpu_down_read(&mem_hotplug_lock
);
62 void put_online_mems(void)
64 percpu_up_read(&mem_hotplug_lock
);
67 bool movable_node_enabled
= false;
69 #ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE
70 int memhp_default_online_type
= MMOP_OFFLINE
;
72 int memhp_default_online_type
= MMOP_ONLINE
;
75 static int __init
setup_memhp_default_state(char *str
)
77 const int online_type
= memhp_online_type_from_str(str
);
80 memhp_default_online_type
= online_type
;
84 __setup("memhp_default_state=", setup_memhp_default_state
);
86 void mem_hotplug_begin(void)
89 percpu_down_write(&mem_hotplug_lock
);
92 void mem_hotplug_done(void)
94 percpu_up_write(&mem_hotplug_lock
);
98 u64 max_mem_size
= U64_MAX
;
100 /* add this memory to iomem resource */
101 static struct resource
*register_memory_resource(u64 start
, u64 size
,
102 const char *resource_name
)
104 struct resource
*res
;
105 unsigned long flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
107 if (strcmp(resource_name
, "System RAM"))
108 flags
|= IORESOURCE_MEM_DRIVER_MANAGED
;
111 * Make sure value parsed from 'mem=' only restricts memory adding
112 * while booting, so that memory hotplug won't be impacted. Please
113 * refer to document of 'mem=' in kernel-parameters.txt for more
116 if (start
+ size
> max_mem_size
&& system_state
< SYSTEM_RUNNING
)
117 return ERR_PTR(-E2BIG
);
120 * Request ownership of the new memory range. This might be
121 * a child of an existing resource that was present but
122 * not marked as busy.
124 res
= __request_region(&iomem_resource
, start
, size
,
125 resource_name
, flags
);
128 pr_debug("Unable to reserve System RAM region: %016llx->%016llx\n",
129 start
, start
+ size
);
130 return ERR_PTR(-EEXIST
);
135 static void release_memory_resource(struct resource
*res
)
139 release_resource(res
);
143 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
144 void get_page_bootmem(unsigned long info
, struct page
*page
,
147 page
->freelist
= (void *)type
;
148 SetPagePrivate(page
);
149 set_page_private(page
, info
);
153 void put_page_bootmem(struct page
*page
)
157 type
= (unsigned long) page
->freelist
;
158 BUG_ON(type
< MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE
||
159 type
> MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE
);
161 if (page_ref_dec_return(page
) == 1) {
162 page
->freelist
= NULL
;
163 ClearPagePrivate(page
);
164 set_page_private(page
, 0);
165 INIT_LIST_HEAD(&page
->lru
);
166 free_reserved_page(page
);
170 #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
171 #ifndef CONFIG_SPARSEMEM_VMEMMAP
172 static void register_page_bootmem_info_section(unsigned long start_pfn
)
174 unsigned long mapsize
, section_nr
, i
;
175 struct mem_section
*ms
;
176 struct page
*page
, *memmap
;
177 struct mem_section_usage
*usage
;
179 section_nr
= pfn_to_section_nr(start_pfn
);
180 ms
= __nr_to_section(section_nr
);
182 /* Get section's memmap address */
183 memmap
= sparse_decode_mem_map(ms
->section_mem_map
, section_nr
);
186 * Get page for the memmap's phys address
187 * XXX: need more consideration for sparse_vmemmap...
189 page
= virt_to_page(memmap
);
190 mapsize
= sizeof(struct page
) * PAGES_PER_SECTION
;
191 mapsize
= PAGE_ALIGN(mapsize
) >> PAGE_SHIFT
;
193 /* remember memmap's page */
194 for (i
= 0; i
< mapsize
; i
++, page
++)
195 get_page_bootmem(section_nr
, page
, SECTION_INFO
);
198 page
= virt_to_page(usage
);
200 mapsize
= PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT
;
202 for (i
= 0; i
< mapsize
; i
++, page
++)
203 get_page_bootmem(section_nr
, page
, MIX_SECTION_INFO
);
206 #else /* CONFIG_SPARSEMEM_VMEMMAP */
207 static void register_page_bootmem_info_section(unsigned long start_pfn
)
209 unsigned long mapsize
, section_nr
, i
;
210 struct mem_section
*ms
;
211 struct page
*page
, *memmap
;
212 struct mem_section_usage
*usage
;
214 section_nr
= pfn_to_section_nr(start_pfn
);
215 ms
= __nr_to_section(section_nr
);
217 memmap
= sparse_decode_mem_map(ms
->section_mem_map
, section_nr
);
219 register_page_bootmem_memmap(section_nr
, memmap
, PAGES_PER_SECTION
);
222 page
= virt_to_page(usage
);
224 mapsize
= PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT
;
226 for (i
= 0; i
< mapsize
; i
++, page
++)
227 get_page_bootmem(section_nr
, page
, MIX_SECTION_INFO
);
229 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
231 void __init
register_page_bootmem_info_node(struct pglist_data
*pgdat
)
233 unsigned long i
, pfn
, end_pfn
, nr_pages
;
234 int node
= pgdat
->node_id
;
237 nr_pages
= PAGE_ALIGN(sizeof(struct pglist_data
)) >> PAGE_SHIFT
;
238 page
= virt_to_page(pgdat
);
240 for (i
= 0; i
< nr_pages
; i
++, page
++)
241 get_page_bootmem(node
, page
, NODE_INFO
);
243 pfn
= pgdat
->node_start_pfn
;
244 end_pfn
= pgdat_end_pfn(pgdat
);
246 /* register section info */
247 for (; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
249 * Some platforms can assign the same pfn to multiple nodes - on
250 * node0 as well as nodeN. To avoid registering a pfn against
251 * multiple nodes we check that this pfn does not already
252 * reside in some other nodes.
254 if (pfn_valid(pfn
) && (early_pfn_to_nid(pfn
) == node
))
255 register_page_bootmem_info_section(pfn
);
258 #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */
260 static int check_pfn_span(unsigned long pfn
, unsigned long nr_pages
,
264 * Disallow all operations smaller than a sub-section and only
265 * allow operations smaller than a section for
266 * SPARSEMEM_VMEMMAP. Note that check_hotplug_memory_range()
267 * enforces a larger memory_block_size_bytes() granularity for
268 * memory that will be marked online, so this check should only
269 * fire for direct arch_{add,remove}_memory() users outside of
270 * add_memory_resource().
272 unsigned long min_align
;
274 if (IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP
))
275 min_align
= PAGES_PER_SUBSECTION
;
277 min_align
= PAGES_PER_SECTION
;
278 if (!IS_ALIGNED(pfn
, min_align
)
279 || !IS_ALIGNED(nr_pages
, min_align
)) {
280 WARN(1, "Misaligned __%s_pages start: %#lx end: #%lx\n",
281 reason
, pfn
, pfn
+ nr_pages
- 1);
287 static int check_hotplug_memory_addressable(unsigned long pfn
,
288 unsigned long nr_pages
)
290 const u64 max_addr
= PFN_PHYS(pfn
+ nr_pages
) - 1;
292 if (max_addr
>> MAX_PHYSMEM_BITS
) {
293 const u64 max_allowed
= (1ull << (MAX_PHYSMEM_BITS
+ 1)) - 1;
295 "Hotplugged memory exceeds maximum addressable address, range=%#llx-%#llx, maximum=%#llx\n",
296 (u64
)PFN_PHYS(pfn
), max_addr
, max_allowed
);
304 * Reasonably generic function for adding memory. It is
305 * expected that archs that support memory hotplug will
306 * call this function after deciding the zone to which to
309 int __ref
__add_pages(int nid
, unsigned long pfn
, unsigned long nr_pages
,
310 struct mhp_params
*params
)
312 const unsigned long end_pfn
= pfn
+ nr_pages
;
313 unsigned long cur_nr_pages
;
315 struct vmem_altmap
*altmap
= params
->altmap
;
317 if (WARN_ON_ONCE(!params
->pgprot
.pgprot
))
320 err
= check_hotplug_memory_addressable(pfn
, nr_pages
);
326 * Validate altmap is within bounds of the total request
328 if (altmap
->base_pfn
!= pfn
329 || vmem_altmap_offset(altmap
) > nr_pages
) {
330 pr_warn_once("memory add fail, invalid altmap\n");
336 err
= check_pfn_span(pfn
, nr_pages
, "add");
340 for (; pfn
< end_pfn
; pfn
+= cur_nr_pages
) {
341 /* Select all remaining pages up to the next section boundary */
342 cur_nr_pages
= min(end_pfn
- pfn
,
343 SECTION_ALIGN_UP(pfn
+ 1) - pfn
);
344 err
= sparse_add_section(nid
, pfn
, cur_nr_pages
, altmap
);
349 vmemmap_populate_print_last();
353 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */
354 static unsigned long find_smallest_section_pfn(int nid
, struct zone
*zone
,
355 unsigned long start_pfn
,
356 unsigned long end_pfn
)
358 for (; start_pfn
< end_pfn
; start_pfn
+= PAGES_PER_SUBSECTION
) {
359 if (unlikely(!pfn_to_online_page(start_pfn
)))
362 if (unlikely(pfn_to_nid(start_pfn
) != nid
))
365 if (zone
!= page_zone(pfn_to_page(start_pfn
)))
374 /* find the biggest valid pfn in the range [start_pfn, end_pfn). */
375 static unsigned long find_biggest_section_pfn(int nid
, struct zone
*zone
,
376 unsigned long start_pfn
,
377 unsigned long end_pfn
)
381 /* pfn is the end pfn of a memory section. */
383 for (; pfn
>= start_pfn
; pfn
-= PAGES_PER_SUBSECTION
) {
384 if (unlikely(!pfn_to_online_page(pfn
)))
387 if (unlikely(pfn_to_nid(pfn
) != nid
))
390 if (zone
!= page_zone(pfn_to_page(pfn
)))
399 static void shrink_zone_span(struct zone
*zone
, unsigned long start_pfn
,
400 unsigned long end_pfn
)
403 int nid
= zone_to_nid(zone
);
405 zone_span_writelock(zone
);
406 if (zone
->zone_start_pfn
== start_pfn
) {
408 * If the section is smallest section in the zone, it need
409 * shrink zone->zone_start_pfn and zone->zone_spanned_pages.
410 * In this case, we find second smallest valid mem_section
411 * for shrinking zone.
413 pfn
= find_smallest_section_pfn(nid
, zone
, end_pfn
,
416 zone
->spanned_pages
= zone_end_pfn(zone
) - pfn
;
417 zone
->zone_start_pfn
= pfn
;
419 zone
->zone_start_pfn
= 0;
420 zone
->spanned_pages
= 0;
422 } else if (zone_end_pfn(zone
) == end_pfn
) {
424 * If the section is biggest section in the zone, it need
425 * shrink zone->spanned_pages.
426 * In this case, we find second biggest valid mem_section for
429 pfn
= find_biggest_section_pfn(nid
, zone
, zone
->zone_start_pfn
,
432 zone
->spanned_pages
= pfn
- zone
->zone_start_pfn
+ 1;
434 zone
->zone_start_pfn
= 0;
435 zone
->spanned_pages
= 0;
438 zone_span_writeunlock(zone
);
441 static void update_pgdat_span(struct pglist_data
*pgdat
)
443 unsigned long node_start_pfn
= 0, node_end_pfn
= 0;
446 for (zone
= pgdat
->node_zones
;
447 zone
< pgdat
->node_zones
+ MAX_NR_ZONES
; zone
++) {
448 unsigned long zone_end_pfn
= zone
->zone_start_pfn
+
451 /* No need to lock the zones, they can't change. */
452 if (!zone
->spanned_pages
)
455 node_start_pfn
= zone
->zone_start_pfn
;
456 node_end_pfn
= zone_end_pfn
;
460 if (zone_end_pfn
> node_end_pfn
)
461 node_end_pfn
= zone_end_pfn
;
462 if (zone
->zone_start_pfn
< node_start_pfn
)
463 node_start_pfn
= zone
->zone_start_pfn
;
466 pgdat
->node_start_pfn
= node_start_pfn
;
467 pgdat
->node_spanned_pages
= node_end_pfn
- node_start_pfn
;
470 void __ref
remove_pfn_range_from_zone(struct zone
*zone
,
471 unsigned long start_pfn
,
472 unsigned long nr_pages
)
474 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
477 /* Poison struct pages because they are now uninitialized again. */
478 page_init_poison(pfn_to_page(start_pfn
), sizeof(struct page
) * nr_pages
);
480 #ifdef CONFIG_ZONE_DEVICE
482 * Zone shrinking code cannot properly deal with ZONE_DEVICE. So
483 * we will not try to shrink the zones - which is okay as
484 * set_zone_contiguous() cannot deal with ZONE_DEVICE either way.
486 if (zone_idx(zone
) == ZONE_DEVICE
)
490 clear_zone_contiguous(zone
);
492 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
493 shrink_zone_span(zone
, start_pfn
, start_pfn
+ nr_pages
);
494 update_pgdat_span(pgdat
);
495 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
497 set_zone_contiguous(zone
);
500 static void __remove_section(unsigned long pfn
, unsigned long nr_pages
,
501 unsigned long map_offset
,
502 struct vmem_altmap
*altmap
)
504 struct mem_section
*ms
= __pfn_to_section(pfn
);
506 if (WARN_ON_ONCE(!valid_section(ms
)))
509 sparse_remove_section(ms
, pfn
, nr_pages
, map_offset
, altmap
);
513 * __remove_pages() - remove sections of pages
514 * @pfn: starting pageframe (must be aligned to start of a section)
515 * @nr_pages: number of pages to remove (must be multiple of section size)
516 * @altmap: alternative device page map or %NULL if default memmap is used
518 * Generic helper function to remove section mappings and sysfs entries
519 * for the section of the memory we are removing. Caller needs to make
520 * sure that pages are marked reserved and zones are adjust properly by
521 * calling offline_pages().
523 void __remove_pages(unsigned long pfn
, unsigned long nr_pages
,
524 struct vmem_altmap
*altmap
)
526 const unsigned long end_pfn
= pfn
+ nr_pages
;
527 unsigned long cur_nr_pages
;
528 unsigned long map_offset
= 0;
530 map_offset
= vmem_altmap_offset(altmap
);
532 if (check_pfn_span(pfn
, nr_pages
, "remove"))
535 for (; pfn
< end_pfn
; pfn
+= cur_nr_pages
) {
537 /* Select all remaining pages up to the next section boundary */
538 cur_nr_pages
= min(end_pfn
- pfn
,
539 SECTION_ALIGN_UP(pfn
+ 1) - pfn
);
540 __remove_section(pfn
, cur_nr_pages
, map_offset
, altmap
);
545 int set_online_page_callback(online_page_callback_t callback
)
550 mutex_lock(&online_page_callback_lock
);
552 if (online_page_callback
== generic_online_page
) {
553 online_page_callback
= callback
;
557 mutex_unlock(&online_page_callback_lock
);
562 EXPORT_SYMBOL_GPL(set_online_page_callback
);
564 int restore_online_page_callback(online_page_callback_t callback
)
569 mutex_lock(&online_page_callback_lock
);
571 if (online_page_callback
== callback
) {
572 online_page_callback
= generic_online_page
;
576 mutex_unlock(&online_page_callback_lock
);
581 EXPORT_SYMBOL_GPL(restore_online_page_callback
);
583 void generic_online_page(struct page
*page
, unsigned int order
)
586 * Freeing the page with debug_pagealloc enabled will try to unmap it,
587 * so we should map it first. This is better than introducing a special
588 * case in page freeing fast path.
590 if (debug_pagealloc_enabled_static())
591 kernel_map_pages(page
, 1 << order
, 1);
592 __free_pages_core(page
, order
);
593 totalram_pages_add(1UL << order
);
594 #ifdef CONFIG_HIGHMEM
595 if (PageHighMem(page
))
596 totalhigh_pages_add(1UL << order
);
599 EXPORT_SYMBOL_GPL(generic_online_page
);
601 static int online_pages_range(unsigned long start_pfn
, unsigned long nr_pages
,
604 const unsigned long end_pfn
= start_pfn
+ nr_pages
;
609 * Online the pages. The callback might decide to keep some pages
610 * PG_reserved (to add them to the buddy later), but we still account
611 * them as being online/belonging to this zone ("present").
613 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= 1ul << order
) {
614 order
= min(MAX_ORDER
- 1, get_order(PFN_PHYS(end_pfn
- pfn
)));
615 /* __free_pages_core() wants pfns to be aligned to the order */
616 if (WARN_ON_ONCE(!IS_ALIGNED(pfn
, 1ul << order
)))
618 (*online_page_callback
)(pfn_to_page(pfn
), order
);
621 /* mark all involved sections as online */
622 online_mem_sections(start_pfn
, end_pfn
);
624 *(unsigned long *)arg
+= nr_pages
;
628 /* check which state of node_states will be changed when online memory */
629 static void node_states_check_changes_online(unsigned long nr_pages
,
630 struct zone
*zone
, struct memory_notify
*arg
)
632 int nid
= zone_to_nid(zone
);
634 arg
->status_change_nid
= NUMA_NO_NODE
;
635 arg
->status_change_nid_normal
= NUMA_NO_NODE
;
636 arg
->status_change_nid_high
= NUMA_NO_NODE
;
638 if (!node_state(nid
, N_MEMORY
))
639 arg
->status_change_nid
= nid
;
640 if (zone_idx(zone
) <= ZONE_NORMAL
&& !node_state(nid
, N_NORMAL_MEMORY
))
641 arg
->status_change_nid_normal
= nid
;
642 #ifdef CONFIG_HIGHMEM
643 if (zone_idx(zone
) <= ZONE_HIGHMEM
&& !node_state(nid
, N_HIGH_MEMORY
))
644 arg
->status_change_nid_high
= nid
;
648 static void node_states_set_node(int node
, struct memory_notify
*arg
)
650 if (arg
->status_change_nid_normal
>= 0)
651 node_set_state(node
, N_NORMAL_MEMORY
);
653 if (arg
->status_change_nid_high
>= 0)
654 node_set_state(node
, N_HIGH_MEMORY
);
656 if (arg
->status_change_nid
>= 0)
657 node_set_state(node
, N_MEMORY
);
660 static void __meminit
resize_zone_range(struct zone
*zone
, unsigned long start_pfn
,
661 unsigned long nr_pages
)
663 unsigned long old_end_pfn
= zone_end_pfn(zone
);
665 if (zone_is_empty(zone
) || start_pfn
< zone
->zone_start_pfn
)
666 zone
->zone_start_pfn
= start_pfn
;
668 zone
->spanned_pages
= max(start_pfn
+ nr_pages
, old_end_pfn
) - zone
->zone_start_pfn
;
671 static void __meminit
resize_pgdat_range(struct pglist_data
*pgdat
, unsigned long start_pfn
,
672 unsigned long nr_pages
)
674 unsigned long old_end_pfn
= pgdat_end_pfn(pgdat
);
676 if (!pgdat
->node_spanned_pages
|| start_pfn
< pgdat
->node_start_pfn
)
677 pgdat
->node_start_pfn
= start_pfn
;
679 pgdat
->node_spanned_pages
= max(start_pfn
+ nr_pages
, old_end_pfn
) - pgdat
->node_start_pfn
;
683 * Associate the pfn range with the given zone, initializing the memmaps
684 * and resizing the pgdat/zone data to span the added pages. After this
685 * call, all affected pages are PG_reserved.
687 void __ref
move_pfn_range_to_zone(struct zone
*zone
, unsigned long start_pfn
,
688 unsigned long nr_pages
, struct vmem_altmap
*altmap
)
690 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
691 int nid
= pgdat
->node_id
;
694 clear_zone_contiguous(zone
);
696 /* TODO Huh pgdat is irqsave while zone is not. It used to be like that before */
697 pgdat_resize_lock(pgdat
, &flags
);
698 zone_span_writelock(zone
);
699 if (zone_is_empty(zone
))
700 init_currently_empty_zone(zone
, start_pfn
, nr_pages
);
701 resize_zone_range(zone
, start_pfn
, nr_pages
);
702 zone_span_writeunlock(zone
);
703 resize_pgdat_range(pgdat
, start_pfn
, nr_pages
);
704 pgdat_resize_unlock(pgdat
, &flags
);
707 * TODO now we have a visible range of pages which are not associated
708 * with their zone properly. Not nice but set_pfnblock_flags_mask
709 * expects the zone spans the pfn range. All the pages in the range
710 * are reserved so nobody should be touching them so we should be safe
712 memmap_init_zone(nr_pages
, nid
, zone_idx(zone
), start_pfn
,
713 MEMMAP_HOTPLUG
, altmap
);
715 set_zone_contiguous(zone
);
719 * Returns a default kernel memory zone for the given pfn range.
720 * If no kernel zone covers this pfn range it will automatically go
721 * to the ZONE_NORMAL.
723 static struct zone
*default_kernel_zone_for_pfn(int nid
, unsigned long start_pfn
,
724 unsigned long nr_pages
)
726 struct pglist_data
*pgdat
= NODE_DATA(nid
);
729 for (zid
= 0; zid
<= ZONE_NORMAL
; zid
++) {
730 struct zone
*zone
= &pgdat
->node_zones
[zid
];
732 if (zone_intersects(zone
, start_pfn
, nr_pages
))
736 return &pgdat
->node_zones
[ZONE_NORMAL
];
739 static inline struct zone
*default_zone_for_pfn(int nid
, unsigned long start_pfn
,
740 unsigned long nr_pages
)
742 struct zone
*kernel_zone
= default_kernel_zone_for_pfn(nid
, start_pfn
,
744 struct zone
*movable_zone
= &NODE_DATA(nid
)->node_zones
[ZONE_MOVABLE
];
745 bool in_kernel
= zone_intersects(kernel_zone
, start_pfn
, nr_pages
);
746 bool in_movable
= zone_intersects(movable_zone
, start_pfn
, nr_pages
);
749 * We inherit the existing zone in a simple case where zones do not
750 * overlap in the given range
752 if (in_kernel
^ in_movable
)
753 return (in_kernel
) ? kernel_zone
: movable_zone
;
756 * If the range doesn't belong to any zone or two zones overlap in the
757 * given range then we use movable zone only if movable_node is
758 * enabled because we always online to a kernel zone by default.
760 return movable_node_enabled
? movable_zone
: kernel_zone
;
763 struct zone
* zone_for_pfn_range(int online_type
, int nid
, unsigned start_pfn
,
764 unsigned long nr_pages
)
766 if (online_type
== MMOP_ONLINE_KERNEL
)
767 return default_kernel_zone_for_pfn(nid
, start_pfn
, nr_pages
);
769 if (online_type
== MMOP_ONLINE_MOVABLE
)
770 return &NODE_DATA(nid
)->node_zones
[ZONE_MOVABLE
];
772 return default_zone_for_pfn(nid
, start_pfn
, nr_pages
);
775 int __ref
online_pages(unsigned long pfn
, unsigned long nr_pages
,
776 int online_type
, int nid
)
779 unsigned long onlined_pages
= 0;
781 int need_zonelists_rebuild
= 0;
783 struct memory_notify arg
;
787 /* associate pfn range with the zone */
788 zone
= zone_for_pfn_range(online_type
, nid
, pfn
, nr_pages
);
789 move_pfn_range_to_zone(zone
, pfn
, nr_pages
, NULL
);
792 arg
.nr_pages
= nr_pages
;
793 node_states_check_changes_online(nr_pages
, zone
, &arg
);
795 ret
= memory_notify(MEM_GOING_ONLINE
, &arg
);
796 ret
= notifier_to_errno(ret
);
798 goto failed_addition
;
801 * If this zone is not populated, then it is not in zonelist.
802 * This means the page allocator ignores this zone.
803 * So, zonelist must be updated after online.
805 if (!populated_zone(zone
)) {
806 need_zonelists_rebuild
= 1;
807 setup_zone_pageset(zone
);
810 ret
= walk_system_ram_range(pfn
, nr_pages
, &onlined_pages
,
813 /* not a single memory resource was applicable */
814 if (need_zonelists_rebuild
)
815 zone_pcp_reset(zone
);
816 goto failed_addition
;
819 zone
->present_pages
+= onlined_pages
;
821 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
822 zone
->zone_pgdat
->node_present_pages
+= onlined_pages
;
823 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
827 node_states_set_node(nid
, &arg
);
828 if (need_zonelists_rebuild
)
829 build_all_zonelists(NULL
);
831 zone_pcp_update(zone
);
833 init_per_zone_wmark_min();
838 vm_total_pages
= nr_free_pagecache_pages();
840 writeback_set_ratelimit();
842 memory_notify(MEM_ONLINE
, &arg
);
847 pr_debug("online_pages [mem %#010llx-%#010llx] failed\n",
848 (unsigned long long) pfn
<< PAGE_SHIFT
,
849 (((unsigned long long) pfn
+ nr_pages
) << PAGE_SHIFT
) - 1);
850 memory_notify(MEM_CANCEL_ONLINE
, &arg
);
851 remove_pfn_range_from_zone(zone
, pfn
, nr_pages
);
855 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
857 static void reset_node_present_pages(pg_data_t
*pgdat
)
861 for (z
= pgdat
->node_zones
; z
< pgdat
->node_zones
+ MAX_NR_ZONES
; z
++)
862 z
->present_pages
= 0;
864 pgdat
->node_present_pages
= 0;
867 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
868 static pg_data_t __ref
*hotadd_new_pgdat(int nid
)
870 struct pglist_data
*pgdat
;
872 pgdat
= NODE_DATA(nid
);
874 pgdat
= arch_alloc_nodedata(nid
);
878 pgdat
->per_cpu_nodestats
=
879 alloc_percpu(struct per_cpu_nodestat
);
880 arch_refresh_nodedata(nid
, pgdat
);
884 * Reset the nr_zones, order and highest_zoneidx before reuse.
885 * Note that kswapd will init kswapd_highest_zoneidx properly
886 * when it starts in the near future.
889 pgdat
->kswapd_order
= 0;
890 pgdat
->kswapd_highest_zoneidx
= 0;
891 for_each_online_cpu(cpu
) {
892 struct per_cpu_nodestat
*p
;
894 p
= per_cpu_ptr(pgdat
->per_cpu_nodestats
, cpu
);
895 memset(p
, 0, sizeof(*p
));
899 /* we can use NODE_DATA(nid) from here */
900 pgdat
->node_id
= nid
;
901 pgdat
->node_start_pfn
= 0;
903 /* init node's zones as empty zones, we don't have any present pages.*/
904 free_area_init_core_hotplug(nid
);
907 * The node we allocated has no zone fallback lists. For avoiding
908 * to access not-initialized zonelist, build here.
910 build_all_zonelists(pgdat
);
913 * When memory is hot-added, all the memory is in offline state. So
914 * clear all zones' present_pages because they will be updated in
915 * online_pages() and offline_pages().
917 reset_node_managed_pages(pgdat
);
918 reset_node_present_pages(pgdat
);
923 static void rollback_node_hotadd(int nid
)
925 pg_data_t
*pgdat
= NODE_DATA(nid
);
927 arch_refresh_nodedata(nid
, NULL
);
928 free_percpu(pgdat
->per_cpu_nodestats
);
929 arch_free_nodedata(pgdat
);
934 * try_online_node - online a node if offlined
936 * @set_node_online: Whether we want to online the node
937 * called by cpu_up() to online a node without onlined memory.
940 * 1 -> a new node has been allocated
941 * 0 -> the node is already online
942 * -ENOMEM -> the node could not be allocated
944 static int __try_online_node(int nid
, bool set_node_online
)
949 if (node_online(nid
))
952 pgdat
= hotadd_new_pgdat(nid
);
954 pr_err("Cannot online node %d due to NULL pgdat\n", nid
);
959 if (set_node_online
) {
960 node_set_online(nid
);
961 ret
= register_one_node(nid
);
969 * Users of this function always want to online/register the node
971 int try_online_node(int nid
)
976 ret
= __try_online_node(nid
, true);
981 static int check_hotplug_memory_range(u64 start
, u64 size
)
983 /* memory range must be block size aligned */
984 if (!size
|| !IS_ALIGNED(start
, memory_block_size_bytes()) ||
985 !IS_ALIGNED(size
, memory_block_size_bytes())) {
986 pr_err("Block size [%#lx] unaligned hotplug range: start %#llx, size %#llx",
987 memory_block_size_bytes(), start
, size
);
994 static int online_memory_block(struct memory_block
*mem
, void *arg
)
996 mem
->online_type
= memhp_default_online_type
;
997 return device_online(&mem
->dev
);
1001 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
1002 * and online/offline operations (triggered e.g. by sysfs).
1004 * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG
1006 int __ref
add_memory_resource(int nid
, struct resource
*res
)
1008 struct mhp_params params
= { .pgprot
= PAGE_KERNEL
};
1010 bool new_node
= false;
1014 size
= resource_size(res
);
1016 ret
= check_hotplug_memory_range(start
, size
);
1020 if (!node_possible(nid
)) {
1021 WARN(1, "node %d was absent from the node_possible_map\n", nid
);
1025 mem_hotplug_begin();
1027 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK
))
1028 memblock_add_node(start
, size
, nid
);
1030 ret
= __try_online_node(nid
, false);
1035 /* call arch's memory hotadd */
1036 ret
= arch_add_memory(nid
, start
, size
, ¶ms
);
1040 /* create memory block devices after memory was added */
1041 ret
= create_memory_block_devices(start
, size
);
1043 arch_remove_memory(nid
, start
, size
, NULL
);
1048 /* If sysfs file of new node can't be created, cpu on the node
1049 * can't be hot-added. There is no rollback way now.
1050 * So, check by BUG_ON() to catch it reluctantly..
1051 * We online node here. We can't roll back from here.
1053 node_set_online(nid
);
1054 ret
= __register_one_node(nid
);
1058 /* link memory sections under this node.*/
1059 ret
= link_mem_sections(nid
, PFN_DOWN(start
), PFN_UP(start
+ size
- 1));
1062 /* create new memmap entry */
1063 if (!strcmp(res
->name
, "System RAM"))
1064 firmware_map_add_hotplug(start
, start
+ size
, "System RAM");
1066 /* device_online() will take the lock when calling online_pages() */
1069 /* online pages if requested */
1070 if (memhp_default_online_type
!= MMOP_OFFLINE
)
1071 walk_memory_blocks(start
, size
, NULL
, online_memory_block
);
1075 /* rollback pgdat allocation and others */
1077 rollback_node_hotadd(nid
);
1078 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK
))
1079 memblock_remove(start
, size
);
1084 /* requires device_hotplug_lock, see add_memory_resource() */
1085 int __ref
__add_memory(int nid
, u64 start
, u64 size
)
1087 struct resource
*res
;
1090 res
= register_memory_resource(start
, size
, "System RAM");
1092 return PTR_ERR(res
);
1094 ret
= add_memory_resource(nid
, res
);
1096 release_memory_resource(res
);
1100 int add_memory(int nid
, u64 start
, u64 size
)
1104 lock_device_hotplug();
1105 rc
= __add_memory(nid
, start
, size
);
1106 unlock_device_hotplug();
1110 EXPORT_SYMBOL_GPL(add_memory
);
1113 * Add special, driver-managed memory to the system as system RAM. Such
1114 * memory is not exposed via the raw firmware-provided memmap as system
1115 * RAM, instead, it is detected and added by a driver - during cold boot,
1116 * after a reboot, and after kexec.
1118 * Reasons why this memory should not be used for the initial memmap of a
1119 * kexec kernel or for placing kexec images:
1120 * - The booting kernel is in charge of determining how this memory will be
1121 * used (e.g., use persistent memory as system RAM)
1122 * - Coordination with a hypervisor is required before this memory
1123 * can be used (e.g., inaccessible parts).
1125 * For this memory, no entries in /sys/firmware/memmap ("raw firmware-provided
1126 * memory map") are created. Also, the created memory resource is flagged
1127 * with IORESOURCE_MEM_DRIVER_MANAGED, so in-kernel users can special-case
1128 * this memory as well (esp., not place kexec images onto it).
1130 * The resource_name (visible via /proc/iomem) has to have the format
1131 * "System RAM ($DRIVER)".
1133 int add_memory_driver_managed(int nid
, u64 start
, u64 size
,
1134 const char *resource_name
)
1136 struct resource
*res
;
1139 if (!resource_name
||
1140 strstr(resource_name
, "System RAM (") != resource_name
||
1141 resource_name
[strlen(resource_name
) - 1] != ')')
1144 lock_device_hotplug();
1146 res
= register_memory_resource(start
, size
, resource_name
);
1152 rc
= add_memory_resource(nid
, res
);
1154 release_memory_resource(res
);
1157 unlock_device_hotplug();
1160 EXPORT_SYMBOL_GPL(add_memory_driver_managed
);
1162 #ifdef CONFIG_MEMORY_HOTREMOVE
1164 * Confirm all pages in a range [start, end) belong to the same zone (skipping
1165 * memory holes). When true, return the zone.
1167 struct zone
*test_pages_in_a_zone(unsigned long start_pfn
,
1168 unsigned long end_pfn
)
1170 unsigned long pfn
, sec_end_pfn
;
1171 struct zone
*zone
= NULL
;
1174 for (pfn
= start_pfn
, sec_end_pfn
= SECTION_ALIGN_UP(start_pfn
+ 1);
1176 pfn
= sec_end_pfn
, sec_end_pfn
+= PAGES_PER_SECTION
) {
1177 /* Make sure the memory section is present first */
1178 if (!present_section_nr(pfn_to_section_nr(pfn
)))
1180 for (; pfn
< sec_end_pfn
&& pfn
< end_pfn
;
1181 pfn
+= MAX_ORDER_NR_PAGES
) {
1183 /* This is just a CONFIG_HOLES_IN_ZONE check.*/
1184 while ((i
< MAX_ORDER_NR_PAGES
) &&
1185 !pfn_valid_within(pfn
+ i
))
1187 if (i
== MAX_ORDER_NR_PAGES
|| pfn
+ i
>= end_pfn
)
1189 /* Check if we got outside of the zone */
1190 if (zone
&& !zone_spans_pfn(zone
, pfn
+ i
))
1192 page
= pfn_to_page(pfn
+ i
);
1193 if (zone
&& page_zone(page
) != zone
)
1195 zone
= page_zone(page
);
1203 * Scan pfn range [start,end) to find movable/migratable pages (LRU pages,
1204 * non-lru movable pages and hugepages). Will skip over most unmovable
1205 * pages (esp., pages that can be skipped when offlining), but bail out on
1206 * definitely unmovable pages.
1209 * 0 in case a movable page is found and movable_pfn was updated.
1210 * -ENOENT in case no movable page was found.
1211 * -EBUSY in case a definitely unmovable page was found.
1213 static int scan_movable_pages(unsigned long start
, unsigned long end
,
1214 unsigned long *movable_pfn
)
1218 for (pfn
= start
; pfn
< end
; pfn
++) {
1219 struct page
*page
, *head
;
1222 if (!pfn_valid(pfn
))
1224 page
= pfn_to_page(pfn
);
1227 if (__PageMovable(page
))
1231 * PageOffline() pages that are not marked __PageMovable() and
1232 * have a reference count > 0 (after MEM_GOING_OFFLINE) are
1233 * definitely unmovable. If their reference count would be 0,
1234 * they could at least be skipped when offlining memory.
1236 if (PageOffline(page
) && page_count(page
))
1239 if (!PageHuge(page
))
1241 head
= compound_head(page
);
1242 if (page_huge_active(head
))
1244 skip
= compound_nr(head
) - (page
- head
);
1253 static struct page
*new_node_page(struct page
*page
, unsigned long private)
1255 int nid
= page_to_nid(page
);
1256 nodemask_t nmask
= node_states
[N_MEMORY
];
1259 * try to allocate from a different node but reuse this node if there
1260 * are no other online nodes to be used (e.g. we are offlining a part
1261 * of the only existing node)
1263 node_clear(nid
, nmask
);
1264 if (nodes_empty(nmask
))
1265 node_set(nid
, nmask
);
1267 return new_page_nodemask(page
, nid
, &nmask
);
1271 do_migrate_range(unsigned long start_pfn
, unsigned long end_pfn
)
1278 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
1279 if (!pfn_valid(pfn
))
1281 page
= pfn_to_page(pfn
);
1283 if (PageHuge(page
)) {
1284 struct page
*head
= compound_head(page
);
1285 pfn
= page_to_pfn(head
) + compound_nr(head
) - 1;
1286 isolate_huge_page(head
, &source
);
1288 } else if (PageTransHuge(page
))
1289 pfn
= page_to_pfn(compound_head(page
))
1290 + hpage_nr_pages(page
) - 1;
1293 * HWPoison pages have elevated reference counts so the migration would
1294 * fail on them. It also doesn't make any sense to migrate them in the
1295 * first place. Still try to unmap such a page in case it is still mapped
1296 * (e.g. current hwpoison implementation doesn't unmap KSM pages but keep
1297 * the unmap as the catch all safety net).
1299 if (PageHWPoison(page
)) {
1300 if (WARN_ON(PageLRU(page
)))
1301 isolate_lru_page(page
);
1302 if (page_mapped(page
))
1303 try_to_unmap(page
, TTU_IGNORE_MLOCK
| TTU_IGNORE_ACCESS
);
1307 if (!get_page_unless_zero(page
))
1310 * We can skip free pages. And we can deal with pages on
1311 * LRU and non-lru movable pages.
1314 ret
= isolate_lru_page(page
);
1316 ret
= isolate_movable_page(page
, ISOLATE_UNEVICTABLE
);
1317 if (!ret
) { /* Success */
1318 list_add_tail(&page
->lru
, &source
);
1319 if (!__PageMovable(page
))
1320 inc_node_page_state(page
, NR_ISOLATED_ANON
+
1321 page_is_file_lru(page
));
1324 pr_warn("failed to isolate pfn %lx\n", pfn
);
1325 dump_page(page
, "isolation failed");
1329 if (!list_empty(&source
)) {
1330 /* Allocate a new page from the nearest neighbor node */
1331 ret
= migrate_pages(&source
, new_node_page
, NULL
, 0,
1332 MIGRATE_SYNC
, MR_MEMORY_HOTPLUG
);
1334 list_for_each_entry(page
, &source
, lru
) {
1335 pr_warn("migrating pfn %lx failed ret:%d ",
1336 page_to_pfn(page
), ret
);
1337 dump_page(page
, "migration failure");
1339 putback_movable_pages(&source
);
1346 /* Mark all sections offline and remove all free pages from the buddy. */
1348 offline_isolated_pages_cb(unsigned long start
, unsigned long nr_pages
,
1351 unsigned long *offlined_pages
= (unsigned long *)data
;
1353 *offlined_pages
+= __offline_isolated_pages(start
, start
+ nr_pages
);
1358 * Check all pages in range, recorded as memory resource, are isolated.
1361 check_pages_isolated_cb(unsigned long start_pfn
, unsigned long nr_pages
,
1364 return test_pages_isolated(start_pfn
, start_pfn
+ nr_pages
,
1368 static int __init
cmdline_parse_movable_node(char *p
)
1370 movable_node_enabled
= true;
1373 early_param("movable_node", cmdline_parse_movable_node
);
1375 /* check which state of node_states will be changed when offline memory */
1376 static void node_states_check_changes_offline(unsigned long nr_pages
,
1377 struct zone
*zone
, struct memory_notify
*arg
)
1379 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
1380 unsigned long present_pages
= 0;
1383 arg
->status_change_nid
= NUMA_NO_NODE
;
1384 arg
->status_change_nid_normal
= NUMA_NO_NODE
;
1385 arg
->status_change_nid_high
= NUMA_NO_NODE
;
1388 * Check whether node_states[N_NORMAL_MEMORY] will be changed.
1389 * If the memory to be offline is within the range
1390 * [0..ZONE_NORMAL], and it is the last present memory there,
1391 * the zones in that range will become empty after the offlining,
1392 * thus we can determine that we need to clear the node from
1393 * node_states[N_NORMAL_MEMORY].
1395 for (zt
= 0; zt
<= ZONE_NORMAL
; zt
++)
1396 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1397 if (zone_idx(zone
) <= ZONE_NORMAL
&& nr_pages
>= present_pages
)
1398 arg
->status_change_nid_normal
= zone_to_nid(zone
);
1400 #ifdef CONFIG_HIGHMEM
1402 * node_states[N_HIGH_MEMORY] contains nodes which
1403 * have normal memory or high memory.
1404 * Here we add the present_pages belonging to ZONE_HIGHMEM.
1405 * If the zone is within the range of [0..ZONE_HIGHMEM), and
1406 * we determine that the zones in that range become empty,
1407 * we need to clear the node for N_HIGH_MEMORY.
1409 present_pages
+= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
1410 if (zone_idx(zone
) <= ZONE_HIGHMEM
&& nr_pages
>= present_pages
)
1411 arg
->status_change_nid_high
= zone_to_nid(zone
);
1415 * We have accounted the pages from [0..ZONE_NORMAL), and
1416 * in case of CONFIG_HIGHMEM the pages from ZONE_HIGHMEM
1418 * Here we count the possible pages from ZONE_MOVABLE.
1419 * If after having accounted all the pages, we see that the nr_pages
1420 * to be offlined is over or equal to the accounted pages,
1421 * we know that the node will become empty, and so, we can clear
1422 * it for N_MEMORY as well.
1424 present_pages
+= pgdat
->node_zones
[ZONE_MOVABLE
].present_pages
;
1426 if (nr_pages
>= present_pages
)
1427 arg
->status_change_nid
= zone_to_nid(zone
);
1430 static void node_states_clear_node(int node
, struct memory_notify
*arg
)
1432 if (arg
->status_change_nid_normal
>= 0)
1433 node_clear_state(node
, N_NORMAL_MEMORY
);
1435 if (arg
->status_change_nid_high
>= 0)
1436 node_clear_state(node
, N_HIGH_MEMORY
);
1438 if (arg
->status_change_nid
>= 0)
1439 node_clear_state(node
, N_MEMORY
);
1442 static int count_system_ram_pages_cb(unsigned long start_pfn
,
1443 unsigned long nr_pages
, void *data
)
1445 unsigned long *nr_system_ram_pages
= data
;
1447 *nr_system_ram_pages
+= nr_pages
;
1451 static int __ref
__offline_pages(unsigned long start_pfn
,
1452 unsigned long end_pfn
)
1454 unsigned long pfn
, nr_pages
= 0;
1455 unsigned long offlined_pages
= 0;
1456 int ret
, node
, nr_isolate_pageblock
;
1457 unsigned long flags
;
1459 struct memory_notify arg
;
1462 mem_hotplug_begin();
1465 * Don't allow to offline memory blocks that contain holes.
1466 * Consequently, memory blocks with holes can never get onlined
1467 * via the hotplug path - online_pages() - as hotplugged memory has
1468 * no holes. This way, we e.g., don't have to worry about marking
1469 * memory holes PG_reserved, don't need pfn_valid() checks, and can
1470 * avoid using walk_system_ram_range() later.
1472 walk_system_ram_range(start_pfn
, end_pfn
- start_pfn
, &nr_pages
,
1473 count_system_ram_pages_cb
);
1474 if (nr_pages
!= end_pfn
- start_pfn
) {
1476 reason
= "memory holes";
1477 goto failed_removal
;
1480 /* This makes hotplug much easier...and readable.
1481 we assume this for now. .*/
1482 zone
= test_pages_in_a_zone(start_pfn
, end_pfn
);
1485 reason
= "multizone range";
1486 goto failed_removal
;
1488 node
= zone_to_nid(zone
);
1490 /* set above range as isolated */
1491 ret
= start_isolate_page_range(start_pfn
, end_pfn
,
1493 MEMORY_OFFLINE
| REPORT_FAILURE
);
1495 reason
= "failure to isolate range";
1496 goto failed_removal
;
1498 nr_isolate_pageblock
= ret
;
1500 arg
.start_pfn
= start_pfn
;
1501 arg
.nr_pages
= nr_pages
;
1502 node_states_check_changes_offline(nr_pages
, zone
, &arg
);
1504 ret
= memory_notify(MEM_GOING_OFFLINE
, &arg
);
1505 ret
= notifier_to_errno(ret
);
1507 reason
= "notifier failure";
1508 goto failed_removal_isolated
;
1514 if (signal_pending(current
)) {
1516 reason
= "signal backoff";
1517 goto failed_removal_isolated
;
1521 lru_add_drain_all();
1523 ret
= scan_movable_pages(pfn
, end_pfn
, &pfn
);
1526 * TODO: fatal migration failures should bail
1529 do_migrate_range(pfn
, end_pfn
);
1533 if (ret
!= -ENOENT
) {
1534 reason
= "unmovable page";
1535 goto failed_removal_isolated
;
1539 * Dissolve free hugepages in the memory block before doing
1540 * offlining actually in order to make hugetlbfs's object
1541 * counting consistent.
1543 ret
= dissolve_free_huge_pages(start_pfn
, end_pfn
);
1545 reason
= "failure to dissolve huge pages";
1546 goto failed_removal_isolated
;
1549 ret
= walk_system_ram_range(start_pfn
, end_pfn
- start_pfn
,
1550 NULL
, check_pages_isolated_cb
);
1553 /* Ok, all of our target is isolated.
1554 We cannot do rollback at this point. */
1555 walk_system_ram_range(start_pfn
, end_pfn
- start_pfn
,
1556 &offlined_pages
, offline_isolated_pages_cb
);
1557 pr_info("Offlined Pages %ld\n", offlined_pages
);
1559 * Onlining will reset pagetype flags and makes migrate type
1560 * MOVABLE, so just need to decrease the number of isolated
1561 * pageblocks zone counter here.
1563 spin_lock_irqsave(&zone
->lock
, flags
);
1564 zone
->nr_isolate_pageblock
-= nr_isolate_pageblock
;
1565 spin_unlock_irqrestore(&zone
->lock
, flags
);
1567 /* removal success */
1568 adjust_managed_page_count(pfn_to_page(start_pfn
), -offlined_pages
);
1569 zone
->present_pages
-= offlined_pages
;
1571 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
1572 zone
->zone_pgdat
->node_present_pages
-= offlined_pages
;
1573 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
1575 init_per_zone_wmark_min();
1577 if (!populated_zone(zone
)) {
1578 zone_pcp_reset(zone
);
1579 build_all_zonelists(NULL
);
1581 zone_pcp_update(zone
);
1583 node_states_clear_node(node
, &arg
);
1584 if (arg
.status_change_nid
>= 0) {
1586 kcompactd_stop(node
);
1589 vm_total_pages
= nr_free_pagecache_pages();
1590 writeback_set_ratelimit();
1592 memory_notify(MEM_OFFLINE
, &arg
);
1593 remove_pfn_range_from_zone(zone
, start_pfn
, nr_pages
);
1597 failed_removal_isolated
:
1598 undo_isolate_page_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
);
1599 memory_notify(MEM_CANCEL_OFFLINE
, &arg
);
1601 pr_debug("memory offlining [mem %#010llx-%#010llx] failed due to %s\n",
1602 (unsigned long long) start_pfn
<< PAGE_SHIFT
,
1603 ((unsigned long long) end_pfn
<< PAGE_SHIFT
) - 1,
1605 /* pushback to free area */
1610 int offline_pages(unsigned long start_pfn
, unsigned long nr_pages
)
1612 return __offline_pages(start_pfn
, start_pfn
+ nr_pages
);
1615 static int check_memblock_offlined_cb(struct memory_block
*mem
, void *arg
)
1617 int ret
= !is_memblock_offlined(mem
);
1619 if (unlikely(ret
)) {
1620 phys_addr_t beginpa
, endpa
;
1622 beginpa
= PFN_PHYS(section_nr_to_pfn(mem
->start_section_nr
));
1623 endpa
= beginpa
+ memory_block_size_bytes() - 1;
1624 pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n",
1632 static int check_cpu_on_node(pg_data_t
*pgdat
)
1636 for_each_present_cpu(cpu
) {
1637 if (cpu_to_node(cpu
) == pgdat
->node_id
)
1639 * the cpu on this node isn't removed, and we can't
1640 * offline this node.
1648 static int check_no_memblock_for_node_cb(struct memory_block
*mem
, void *arg
)
1650 int nid
= *(int *)arg
;
1653 * If a memory block belongs to multiple nodes, the stored nid is not
1654 * reliable. However, such blocks are always online (e.g., cannot get
1655 * offlined) and, therefore, are still spanned by the node.
1657 return mem
->nid
== nid
? -EEXIST
: 0;
1664 * Offline a node if all memory sections and cpus of the node are removed.
1666 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
1667 * and online/offline operations before this call.
1669 void try_offline_node(int nid
)
1671 pg_data_t
*pgdat
= NODE_DATA(nid
);
1675 * If the node still spans pages (especially ZONE_DEVICE), don't
1676 * offline it. A node spans memory after move_pfn_range_to_zone(),
1677 * e.g., after the memory block was onlined.
1679 if (pgdat
->node_spanned_pages
)
1683 * Especially offline memory blocks might not be spanned by the
1684 * node. They will get spanned by the node once they get onlined.
1685 * However, they link to the node in sysfs and can get onlined later.
1687 rc
= for_each_memory_block(&nid
, check_no_memblock_for_node_cb
);
1691 if (check_cpu_on_node(pgdat
))
1695 * all memory/cpu of this node are removed, we can offline this
1698 node_set_offline(nid
);
1699 unregister_one_node(nid
);
1701 EXPORT_SYMBOL(try_offline_node
);
1703 static void __release_memory_resource(resource_size_t start
,
1704 resource_size_t size
)
1709 * When removing memory in the same granularity as it was added,
1710 * this function never fails. It might only fail if resources
1711 * have to be adjusted or split. We'll ignore the error, as
1712 * removing of memory cannot fail.
1714 ret
= release_mem_region_adjustable(&iomem_resource
, start
, size
);
1716 resource_size_t endres
= start
+ size
- 1;
1718 pr_warn("Unable to release resource <%pa-%pa> (%d)\n",
1719 &start
, &endres
, ret
);
1723 static int __ref
try_remove_memory(int nid
, u64 start
, u64 size
)
1727 BUG_ON(check_hotplug_memory_range(start
, size
));
1730 * All memory blocks must be offlined before removing memory. Check
1731 * whether all memory blocks in question are offline and return error
1732 * if this is not the case.
1734 rc
= walk_memory_blocks(start
, size
, NULL
, check_memblock_offlined_cb
);
1738 /* remove memmap entry */
1739 firmware_map_remove(start
, start
+ size
, "System RAM");
1742 * Memory block device removal under the device_hotplug_lock is
1743 * a barrier against racing online attempts.
1745 remove_memory_block_devices(start
, size
);
1747 mem_hotplug_begin();
1749 arch_remove_memory(nid
, start
, size
, NULL
);
1751 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK
)) {
1752 memblock_free(start
, size
);
1753 memblock_remove(start
, size
);
1756 __release_memory_resource(start
, size
);
1758 try_offline_node(nid
);
1768 * @start: physical address of the region to remove
1769 * @size: size of the region to remove
1771 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
1772 * and online/offline operations before this call, as required by
1773 * try_offline_node().
1775 void __remove_memory(int nid
, u64 start
, u64 size
)
1779 * trigger BUG() if some memory is not offlined prior to calling this
1782 if (try_remove_memory(nid
, start
, size
))
1787 * Remove memory if every memory block is offline, otherwise return -EBUSY is
1788 * some memory is not offline
1790 int remove_memory(int nid
, u64 start
, u64 size
)
1794 lock_device_hotplug();
1795 rc
= try_remove_memory(nid
, start
, size
);
1796 unlock_device_hotplug();
1800 EXPORT_SYMBOL_GPL(remove_memory
);
1803 * Try to offline and remove a memory block. Might take a long time to
1804 * finish in case memory is still in use. Primarily useful for memory devices
1805 * that logically unplugged all memory (so it's no longer in use) and want to
1806 * offline + remove the memory block.
1808 int offline_and_remove_memory(int nid
, u64 start
, u64 size
)
1810 struct memory_block
*mem
;
1813 if (!IS_ALIGNED(start
, memory_block_size_bytes()) ||
1814 size
!= memory_block_size_bytes())
1817 lock_device_hotplug();
1818 mem
= find_memory_block(__pfn_to_section(PFN_DOWN(start
)));
1820 rc
= device_offline(&mem
->dev
);
1821 /* Ignore if the device is already offline. */
1826 * In case we succeeded to offline the memory block, remove it.
1827 * This cannot fail as it cannot get onlined in the meantime.
1830 rc
= try_remove_memory(nid
, start
, size
);
1833 unlock_device_hotplug();
1837 EXPORT_SYMBOL_GPL(offline_and_remove_memory
);
1838 #endif /* CONFIG_MEMORY_HOTREMOVE */