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 #ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE
83 bool memhp_auto_online
;
85 bool memhp_auto_online
= true;
87 EXPORT_SYMBOL_GPL(memhp_auto_online
);
89 static int __init
setup_memhp_default_state(char *str
)
91 if (!strcmp(str
, "online"))
92 memhp_auto_online
= true;
93 else if (!strcmp(str
, "offline"))
94 memhp_auto_online
= false;
98 __setup("memhp_default_state=", setup_memhp_default_state
);
100 void get_online_mems(void)
103 if (mem_hotplug
.active_writer
== current
)
105 memhp_lock_acquire_read();
106 mutex_lock(&mem_hotplug
.lock
);
107 mem_hotplug
.refcount
++;
108 mutex_unlock(&mem_hotplug
.lock
);
112 void put_online_mems(void)
114 if (mem_hotplug
.active_writer
== current
)
116 mutex_lock(&mem_hotplug
.lock
);
118 if (WARN_ON(!mem_hotplug
.refcount
))
119 mem_hotplug
.refcount
++; /* try to fix things up */
121 if (!--mem_hotplug
.refcount
&& unlikely(mem_hotplug
.active_writer
))
122 wake_up_process(mem_hotplug
.active_writer
);
123 mutex_unlock(&mem_hotplug
.lock
);
124 memhp_lock_release();
128 /* Serializes write accesses to mem_hotplug.active_writer. */
129 static DEFINE_MUTEX(memory_add_remove_lock
);
131 void mem_hotplug_begin(void)
133 mutex_lock(&memory_add_remove_lock
);
135 mem_hotplug
.active_writer
= current
;
137 memhp_lock_acquire();
139 mutex_lock(&mem_hotplug
.lock
);
140 if (likely(!mem_hotplug
.refcount
))
142 __set_current_state(TASK_UNINTERRUPTIBLE
);
143 mutex_unlock(&mem_hotplug
.lock
);
148 void mem_hotplug_done(void)
150 mem_hotplug
.active_writer
= NULL
;
151 mutex_unlock(&mem_hotplug
.lock
);
152 memhp_lock_release();
153 mutex_unlock(&memory_add_remove_lock
);
156 /* add this memory to iomem resource */
157 static struct resource
*register_memory_resource(u64 start
, u64 size
)
159 struct resource
*res
;
160 res
= kzalloc(sizeof(struct resource
), GFP_KERNEL
);
162 return ERR_PTR(-ENOMEM
);
164 res
->name
= "System RAM";
166 res
->end
= start
+ size
- 1;
167 res
->flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
168 if (request_resource(&iomem_resource
, res
) < 0) {
169 pr_debug("System RAM resource %pR cannot be added\n", res
);
171 return ERR_PTR(-EEXIST
);
176 static void release_memory_resource(struct resource
*res
)
180 release_resource(res
);
185 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
186 void get_page_bootmem(unsigned long info
, struct page
*page
,
189 page
->freelist
= (void *)type
;
190 SetPagePrivate(page
);
191 set_page_private(page
, info
);
195 void put_page_bootmem(struct page
*page
)
199 type
= (unsigned long) page
->freelist
;
200 BUG_ON(type
< MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE
||
201 type
> MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE
);
203 if (page_ref_dec_return(page
) == 1) {
204 page
->freelist
= NULL
;
205 ClearPagePrivate(page
);
206 set_page_private(page
, 0);
207 INIT_LIST_HEAD(&page
->lru
);
208 free_reserved_page(page
);
212 #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
213 #ifndef CONFIG_SPARSEMEM_VMEMMAP
214 static void register_page_bootmem_info_section(unsigned long start_pfn
)
216 unsigned long *usemap
, mapsize
, section_nr
, i
;
217 struct mem_section
*ms
;
218 struct page
*page
, *memmap
;
220 section_nr
= pfn_to_section_nr(start_pfn
);
221 ms
= __nr_to_section(section_nr
);
223 /* Get section's memmap address */
224 memmap
= sparse_decode_mem_map(ms
->section_mem_map
, section_nr
);
227 * Get page for the memmap's phys address
228 * XXX: need more consideration for sparse_vmemmap...
230 page
= virt_to_page(memmap
);
231 mapsize
= sizeof(struct page
) * PAGES_PER_SECTION
;
232 mapsize
= PAGE_ALIGN(mapsize
) >> PAGE_SHIFT
;
234 /* remember memmap's page */
235 for (i
= 0; i
< mapsize
; i
++, page
++)
236 get_page_bootmem(section_nr
, page
, SECTION_INFO
);
238 usemap
= __nr_to_section(section_nr
)->pageblock_flags
;
239 page
= virt_to_page(usemap
);
241 mapsize
= PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT
;
243 for (i
= 0; i
< mapsize
; i
++, page
++)
244 get_page_bootmem(section_nr
, page
, MIX_SECTION_INFO
);
247 #else /* CONFIG_SPARSEMEM_VMEMMAP */
248 static void register_page_bootmem_info_section(unsigned long start_pfn
)
250 unsigned long *usemap
, mapsize
, section_nr
, i
;
251 struct mem_section
*ms
;
252 struct page
*page
, *memmap
;
254 if (!pfn_valid(start_pfn
))
257 section_nr
= pfn_to_section_nr(start_pfn
);
258 ms
= __nr_to_section(section_nr
);
260 memmap
= sparse_decode_mem_map(ms
->section_mem_map
, section_nr
);
262 register_page_bootmem_memmap(section_nr
, memmap
, PAGES_PER_SECTION
);
264 usemap
= __nr_to_section(section_nr
)->pageblock_flags
;
265 page
= virt_to_page(usemap
);
267 mapsize
= PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT
;
269 for (i
= 0; i
< mapsize
; i
++, page
++)
270 get_page_bootmem(section_nr
, page
, MIX_SECTION_INFO
);
272 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
274 void __init
register_page_bootmem_info_node(struct pglist_data
*pgdat
)
276 unsigned long i
, pfn
, end_pfn
, nr_pages
;
277 int node
= pgdat
->node_id
;
280 nr_pages
= PAGE_ALIGN(sizeof(struct pglist_data
)) >> PAGE_SHIFT
;
281 page
= virt_to_page(pgdat
);
283 for (i
= 0; i
< nr_pages
; i
++, page
++)
284 get_page_bootmem(node
, page
, NODE_INFO
);
286 pfn
= pgdat
->node_start_pfn
;
287 end_pfn
= pgdat_end_pfn(pgdat
);
289 /* register section info */
290 for (; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
292 * Some platforms can assign the same pfn to multiple nodes - on
293 * node0 as well as nodeN. To avoid registering a pfn against
294 * multiple nodes we check that this pfn does not already
295 * reside in some other nodes.
297 if (pfn_valid(pfn
) && (early_pfn_to_nid(pfn
) == node
))
298 register_page_bootmem_info_section(pfn
);
301 #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */
303 static int __meminit
__add_section(int nid
, unsigned long phys_start_pfn
,
309 if (pfn_valid(phys_start_pfn
))
312 ret
= sparse_add_one_section(NODE_DATA(nid
), phys_start_pfn
);
317 * Make all the pages reserved so that nobody will stumble over half
319 * FIXME: We also have to associate it with a node because pfn_to_node
320 * relies on having page with the proper node.
322 for (i
= 0; i
< PAGES_PER_SECTION
; i
++) {
323 unsigned long pfn
= phys_start_pfn
+ i
;
328 page
= pfn_to_page(pfn
);
329 set_page_node(page
, nid
);
330 SetPageReserved(page
);
336 return register_new_memory(nid
, __pfn_to_section(phys_start_pfn
));
340 * Reasonably generic function for adding memory. It is
341 * expected that archs that support memory hotplug will
342 * call this function after deciding the zone to which to
345 int __ref
__add_pages(int nid
, unsigned long phys_start_pfn
,
346 unsigned long nr_pages
, bool want_memblock
)
350 int start_sec
, end_sec
;
351 struct vmem_altmap
*altmap
;
353 /* during initialize mem_map, align hot-added range to section */
354 start_sec
= pfn_to_section_nr(phys_start_pfn
);
355 end_sec
= pfn_to_section_nr(phys_start_pfn
+ nr_pages
- 1);
357 altmap
= to_vmem_altmap((unsigned long) pfn_to_page(phys_start_pfn
));
360 * Validate altmap is within bounds of the total request
362 if (altmap
->base_pfn
!= phys_start_pfn
363 || vmem_altmap_offset(altmap
) > nr_pages
) {
364 pr_warn_once("memory add fail, invalid altmap\n");
371 for (i
= start_sec
; i
<= end_sec
; i
++) {
372 err
= __add_section(nid
, section_nr_to_pfn(i
), want_memblock
);
375 * EEXIST is finally dealt with by ioresource collision
376 * check. see add_memory() => register_memory_resource()
377 * Warning will be printed if there is collision.
379 if (err
&& (err
!= -EEXIST
))
383 vmemmap_populate_print_last();
387 EXPORT_SYMBOL_GPL(__add_pages
);
389 #ifdef CONFIG_MEMORY_HOTREMOVE
390 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */
391 static int find_smallest_section_pfn(int nid
, struct zone
*zone
,
392 unsigned long start_pfn
,
393 unsigned long end_pfn
)
395 struct mem_section
*ms
;
397 for (; start_pfn
< end_pfn
; start_pfn
+= PAGES_PER_SECTION
) {
398 ms
= __pfn_to_section(start_pfn
);
400 if (unlikely(!valid_section(ms
)))
403 if (unlikely(pfn_to_nid(start_pfn
) != nid
))
406 if (zone
&& zone
!= page_zone(pfn_to_page(start_pfn
)))
415 /* find the biggest valid pfn in the range [start_pfn, end_pfn). */
416 static int find_biggest_section_pfn(int nid
, struct zone
*zone
,
417 unsigned long start_pfn
,
418 unsigned long end_pfn
)
420 struct mem_section
*ms
;
423 /* pfn is the end pfn of a memory section. */
425 for (; pfn
>= start_pfn
; pfn
-= PAGES_PER_SECTION
) {
426 ms
= __pfn_to_section(pfn
);
428 if (unlikely(!valid_section(ms
)))
431 if (unlikely(pfn_to_nid(pfn
) != nid
))
434 if (zone
&& zone
!= page_zone(pfn_to_page(pfn
)))
443 static void shrink_zone_span(struct zone
*zone
, unsigned long start_pfn
,
444 unsigned long end_pfn
)
446 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
447 unsigned long z
= zone_end_pfn(zone
); /* zone_end_pfn namespace clash */
448 unsigned long zone_end_pfn
= z
;
450 struct mem_section
*ms
;
451 int nid
= zone_to_nid(zone
);
453 zone_span_writelock(zone
);
454 if (zone_start_pfn
== start_pfn
) {
456 * If the section is smallest section in the zone, it need
457 * shrink zone->zone_start_pfn and zone->zone_spanned_pages.
458 * In this case, we find second smallest valid mem_section
459 * for shrinking zone.
461 pfn
= find_smallest_section_pfn(nid
, zone
, end_pfn
,
464 zone
->zone_start_pfn
= pfn
;
465 zone
->spanned_pages
= zone_end_pfn
- pfn
;
467 } else if (zone_end_pfn
== end_pfn
) {
469 * If the section is biggest section in the zone, it need
470 * shrink zone->spanned_pages.
471 * In this case, we find second biggest valid mem_section for
474 pfn
= find_biggest_section_pfn(nid
, zone
, zone_start_pfn
,
477 zone
->spanned_pages
= pfn
- zone_start_pfn
+ 1;
481 * The section is not biggest or smallest mem_section in the zone, it
482 * only creates a hole in the zone. So in this case, we need not
483 * change the zone. But perhaps, the zone has only hole data. Thus
484 * it check the zone has only hole or not.
486 pfn
= zone_start_pfn
;
487 for (; pfn
< zone_end_pfn
; pfn
+= PAGES_PER_SECTION
) {
488 ms
= __pfn_to_section(pfn
);
490 if (unlikely(!valid_section(ms
)))
493 if (page_zone(pfn_to_page(pfn
)) != zone
)
496 /* If the section is current section, it continues the loop */
497 if (start_pfn
== pfn
)
500 /* If we find valid section, we have nothing to do */
501 zone_span_writeunlock(zone
);
505 /* The zone has no valid section */
506 zone
->zone_start_pfn
= 0;
507 zone
->spanned_pages
= 0;
508 zone_span_writeunlock(zone
);
511 static void shrink_pgdat_span(struct pglist_data
*pgdat
,
512 unsigned long start_pfn
, unsigned long end_pfn
)
514 unsigned long pgdat_start_pfn
= pgdat
->node_start_pfn
;
515 unsigned long p
= pgdat_end_pfn(pgdat
); /* pgdat_end_pfn namespace clash */
516 unsigned long pgdat_end_pfn
= p
;
518 struct mem_section
*ms
;
519 int nid
= pgdat
->node_id
;
521 if (pgdat_start_pfn
== start_pfn
) {
523 * If the section is smallest section in the pgdat, it need
524 * shrink pgdat->node_start_pfn and pgdat->node_spanned_pages.
525 * In this case, we find second smallest valid mem_section
526 * for shrinking zone.
528 pfn
= find_smallest_section_pfn(nid
, NULL
, end_pfn
,
531 pgdat
->node_start_pfn
= pfn
;
532 pgdat
->node_spanned_pages
= pgdat_end_pfn
- pfn
;
534 } else if (pgdat_end_pfn
== end_pfn
) {
536 * If the section is biggest section in the pgdat, it need
537 * shrink pgdat->node_spanned_pages.
538 * In this case, we find second biggest valid mem_section for
541 pfn
= find_biggest_section_pfn(nid
, NULL
, pgdat_start_pfn
,
544 pgdat
->node_spanned_pages
= pfn
- pgdat_start_pfn
+ 1;
548 * If the section is not biggest or smallest mem_section in the pgdat,
549 * it only creates a hole in the pgdat. So in this case, we need not
551 * But perhaps, the pgdat has only hole data. Thus it check the pgdat
552 * has only hole or not.
554 pfn
= pgdat_start_pfn
;
555 for (; pfn
< pgdat_end_pfn
; pfn
+= PAGES_PER_SECTION
) {
556 ms
= __pfn_to_section(pfn
);
558 if (unlikely(!valid_section(ms
)))
561 if (pfn_to_nid(pfn
) != nid
)
564 /* If the section is current section, it continues the loop */
565 if (start_pfn
== pfn
)
568 /* If we find valid section, we have nothing to do */
572 /* The pgdat has no valid section */
573 pgdat
->node_start_pfn
= 0;
574 pgdat
->node_spanned_pages
= 0;
577 static void __remove_zone(struct zone
*zone
, unsigned long start_pfn
)
579 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
580 int nr_pages
= PAGES_PER_SECTION
;
584 zone_type
= zone
- pgdat
->node_zones
;
586 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
587 shrink_zone_span(zone
, start_pfn
, start_pfn
+ nr_pages
);
588 shrink_pgdat_span(pgdat
, start_pfn
, start_pfn
+ nr_pages
);
589 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
592 static int __remove_section(struct zone
*zone
, struct mem_section
*ms
,
593 unsigned long map_offset
)
595 unsigned long start_pfn
;
599 if (!valid_section(ms
))
602 ret
= unregister_memory_section(ms
);
606 scn_nr
= __section_nr(ms
);
607 start_pfn
= section_nr_to_pfn(scn_nr
);
608 __remove_zone(zone
, start_pfn
);
610 sparse_remove_one_section(zone
, ms
, map_offset
);
615 * __remove_pages() - remove sections of pages from a zone
616 * @zone: zone from which pages need to be removed
617 * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
618 * @nr_pages: number of pages to remove (must be multiple of section size)
620 * Generic helper function to remove section mappings and sysfs entries
621 * for the section of the memory we are removing. Caller needs to make
622 * sure that pages are marked reserved and zones are adjust properly by
623 * calling offline_pages().
625 int __remove_pages(struct zone
*zone
, unsigned long phys_start_pfn
,
626 unsigned long nr_pages
)
629 unsigned long map_offset
= 0;
630 int sections_to_remove
, ret
= 0;
632 /* In the ZONE_DEVICE case device driver owns the memory region */
633 if (is_dev_zone(zone
)) {
634 struct page
*page
= pfn_to_page(phys_start_pfn
);
635 struct vmem_altmap
*altmap
;
637 altmap
= to_vmem_altmap((unsigned long) page
);
639 map_offset
= vmem_altmap_offset(altmap
);
641 resource_size_t start
, size
;
643 start
= phys_start_pfn
<< PAGE_SHIFT
;
644 size
= nr_pages
* PAGE_SIZE
;
646 ret
= release_mem_region_adjustable(&iomem_resource
, start
,
649 resource_size_t endres
= start
+ size
- 1;
651 pr_warn("Unable to release resource <%pa-%pa> (%d)\n",
652 &start
, &endres
, ret
);
656 clear_zone_contiguous(zone
);
659 * We can only remove entire sections
661 BUG_ON(phys_start_pfn
& ~PAGE_SECTION_MASK
);
662 BUG_ON(nr_pages
% PAGES_PER_SECTION
);
664 sections_to_remove
= nr_pages
/ PAGES_PER_SECTION
;
665 for (i
= 0; i
< sections_to_remove
; i
++) {
666 unsigned long pfn
= phys_start_pfn
+ i
*PAGES_PER_SECTION
;
668 ret
= __remove_section(zone
, __pfn_to_section(pfn
), map_offset
);
674 set_zone_contiguous(zone
);
678 #endif /* CONFIG_MEMORY_HOTREMOVE */
680 int set_online_page_callback(online_page_callback_t callback
)
685 mutex_lock(&online_page_callback_lock
);
687 if (online_page_callback
== generic_online_page
) {
688 online_page_callback
= callback
;
692 mutex_unlock(&online_page_callback_lock
);
697 EXPORT_SYMBOL_GPL(set_online_page_callback
);
699 int restore_online_page_callback(online_page_callback_t callback
)
704 mutex_lock(&online_page_callback_lock
);
706 if (online_page_callback
== callback
) {
707 online_page_callback
= generic_online_page
;
711 mutex_unlock(&online_page_callback_lock
);
716 EXPORT_SYMBOL_GPL(restore_online_page_callback
);
718 void __online_page_set_limits(struct page
*page
)
721 EXPORT_SYMBOL_GPL(__online_page_set_limits
);
723 void __online_page_increment_counters(struct page
*page
)
725 adjust_managed_page_count(page
, 1);
727 EXPORT_SYMBOL_GPL(__online_page_increment_counters
);
729 void __online_page_free(struct page
*page
)
731 __free_reserved_page(page
);
733 EXPORT_SYMBOL_GPL(__online_page_free
);
735 static void generic_online_page(struct page
*page
)
737 __online_page_set_limits(page
);
738 __online_page_increment_counters(page
);
739 __online_page_free(page
);
742 static int online_pages_range(unsigned long start_pfn
, unsigned long nr_pages
,
746 unsigned long onlined_pages
= *(unsigned long *)arg
;
749 if (PageReserved(pfn_to_page(start_pfn
)))
750 for (i
= 0; i
< nr_pages
; i
++) {
751 page
= pfn_to_page(start_pfn
+ i
);
752 (*online_page_callback
)(page
);
756 online_mem_sections(start_pfn
, start_pfn
+ nr_pages
);
758 *(unsigned long *)arg
= onlined_pages
;
762 /* check which state of node_states will be changed when online memory */
763 static void node_states_check_changes_online(unsigned long nr_pages
,
764 struct zone
*zone
, struct memory_notify
*arg
)
766 int nid
= zone_to_nid(zone
);
767 enum zone_type zone_last
= ZONE_NORMAL
;
770 * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
771 * contains nodes which have zones of 0...ZONE_NORMAL,
772 * set zone_last to ZONE_NORMAL.
774 * If we don't have HIGHMEM nor movable node,
775 * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
776 * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
778 if (N_MEMORY
== N_NORMAL_MEMORY
)
779 zone_last
= ZONE_MOVABLE
;
782 * if the memory to be online is in a zone of 0...zone_last, and
783 * the zones of 0...zone_last don't have memory before online, we will
784 * need to set the node to node_states[N_NORMAL_MEMORY] after
785 * the memory is online.
787 if (zone_idx(zone
) <= zone_last
&& !node_state(nid
, N_NORMAL_MEMORY
))
788 arg
->status_change_nid_normal
= nid
;
790 arg
->status_change_nid_normal
= -1;
792 #ifdef CONFIG_HIGHMEM
794 * If we have movable node, node_states[N_HIGH_MEMORY]
795 * contains nodes which have zones of 0...ZONE_HIGHMEM,
796 * set zone_last to ZONE_HIGHMEM.
798 * If we don't have movable node, node_states[N_NORMAL_MEMORY]
799 * contains nodes which have zones of 0...ZONE_MOVABLE,
800 * set zone_last to ZONE_MOVABLE.
802 zone_last
= ZONE_HIGHMEM
;
803 if (N_MEMORY
== N_HIGH_MEMORY
)
804 zone_last
= ZONE_MOVABLE
;
806 if (zone_idx(zone
) <= zone_last
&& !node_state(nid
, N_HIGH_MEMORY
))
807 arg
->status_change_nid_high
= nid
;
809 arg
->status_change_nid_high
= -1;
811 arg
->status_change_nid_high
= arg
->status_change_nid_normal
;
815 * if the node don't have memory befor online, we will need to
816 * set the node to node_states[N_MEMORY] after the memory
819 if (!node_state(nid
, N_MEMORY
))
820 arg
->status_change_nid
= nid
;
822 arg
->status_change_nid
= -1;
825 static void node_states_set_node(int node
, struct memory_notify
*arg
)
827 if (arg
->status_change_nid_normal
>= 0)
828 node_set_state(node
, N_NORMAL_MEMORY
);
830 if (arg
->status_change_nid_high
>= 0)
831 node_set_state(node
, N_HIGH_MEMORY
);
833 node_set_state(node
, N_MEMORY
);
836 bool allow_online_pfn_range(int nid
, unsigned long pfn
, unsigned long nr_pages
, int online_type
)
838 struct pglist_data
*pgdat
= NODE_DATA(nid
);
839 struct zone
*movable_zone
= &pgdat
->node_zones
[ZONE_MOVABLE
];
840 struct zone
*default_zone
= default_zone_for_pfn(nid
, pfn
, nr_pages
);
843 * TODO there shouldn't be any inherent reason to have ZONE_NORMAL
844 * physically before ZONE_MOVABLE. All we need is they do not
845 * overlap. Historically we didn't allow ZONE_NORMAL after ZONE_MOVABLE
846 * though so let's stick with it for simplicity for now.
847 * TODO make sure we do not overlap with ZONE_DEVICE
849 if (online_type
== MMOP_ONLINE_KERNEL
) {
850 if (zone_is_empty(movable_zone
))
852 return movable_zone
->zone_start_pfn
>= pfn
+ nr_pages
;
853 } else if (online_type
== MMOP_ONLINE_MOVABLE
) {
854 return zone_end_pfn(default_zone
) <= pfn
;
857 /* MMOP_ONLINE_KEEP will always succeed and inherits the current zone */
858 return online_type
== MMOP_ONLINE_KEEP
;
861 static void __meminit
resize_zone_range(struct zone
*zone
, unsigned long start_pfn
,
862 unsigned long nr_pages
)
864 unsigned long old_end_pfn
= zone_end_pfn(zone
);
866 if (zone_is_empty(zone
) || start_pfn
< zone
->zone_start_pfn
)
867 zone
->zone_start_pfn
= start_pfn
;
869 zone
->spanned_pages
= max(start_pfn
+ nr_pages
, old_end_pfn
) - zone
->zone_start_pfn
;
872 static void __meminit
resize_pgdat_range(struct pglist_data
*pgdat
, unsigned long start_pfn
,
873 unsigned long nr_pages
)
875 unsigned long old_end_pfn
= pgdat_end_pfn(pgdat
);
877 if (!pgdat
->node_spanned_pages
|| start_pfn
< pgdat
->node_start_pfn
)
878 pgdat
->node_start_pfn
= start_pfn
;
880 pgdat
->node_spanned_pages
= max(start_pfn
+ nr_pages
, old_end_pfn
) - pgdat
->node_start_pfn
;
883 void __ref
move_pfn_range_to_zone(struct zone
*zone
,
884 unsigned long start_pfn
, unsigned long nr_pages
)
886 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
887 int nid
= pgdat
->node_id
;
890 if (zone_is_empty(zone
))
891 init_currently_empty_zone(zone
, start_pfn
, nr_pages
);
893 clear_zone_contiguous(zone
);
895 /* TODO Huh pgdat is irqsave while zone is not. It used to be like that before */
896 pgdat_resize_lock(pgdat
, &flags
);
897 zone_span_writelock(zone
);
898 resize_zone_range(zone
, start_pfn
, nr_pages
);
899 zone_span_writeunlock(zone
);
900 resize_pgdat_range(pgdat
, start_pfn
, nr_pages
);
901 pgdat_resize_unlock(pgdat
, &flags
);
904 * TODO now we have a visible range of pages which are not associated
905 * with their zone properly. Not nice but set_pfnblock_flags_mask
906 * expects the zone spans the pfn range. All the pages in the range
907 * are reserved so nobody should be touching them so we should be safe
909 memmap_init_zone(nr_pages
, nid
, zone_idx(zone
), start_pfn
, MEMMAP_HOTPLUG
);
911 set_zone_contiguous(zone
);
915 * Returns a default kernel memory zone for the given pfn range.
916 * If no kernel zone covers this pfn range it will automatically go
917 * to the ZONE_NORMAL.
919 struct zone
*default_zone_for_pfn(int nid
, unsigned long start_pfn
,
920 unsigned long nr_pages
)
922 struct pglist_data
*pgdat
= NODE_DATA(nid
);
925 for (zid
= 0; zid
<= ZONE_NORMAL
; zid
++) {
926 struct zone
*zone
= &pgdat
->node_zones
[zid
];
928 if (zone_intersects(zone
, start_pfn
, nr_pages
))
932 return &pgdat
->node_zones
[ZONE_NORMAL
];
936 * Associates the given pfn range with the given node and the zone appropriate
937 * for the given online type.
939 static struct zone
* __meminit
move_pfn_range(int online_type
, int nid
,
940 unsigned long start_pfn
, unsigned long nr_pages
)
942 struct pglist_data
*pgdat
= NODE_DATA(nid
);
943 struct zone
*zone
= default_zone_for_pfn(nid
, start_pfn
, nr_pages
);
945 if (online_type
== MMOP_ONLINE_KEEP
) {
946 struct zone
*movable_zone
= &pgdat
->node_zones
[ZONE_MOVABLE
];
948 * MMOP_ONLINE_KEEP defaults to MMOP_ONLINE_KERNEL but use
949 * movable zone if that is not possible (e.g. we are within
950 * or past the existing movable zone)
952 if (!allow_online_pfn_range(nid
, start_pfn
, nr_pages
,
955 } else if (online_type
== MMOP_ONLINE_MOVABLE
) {
956 zone
= &pgdat
->node_zones
[ZONE_MOVABLE
];
959 move_pfn_range_to_zone(zone
, start_pfn
, nr_pages
);
963 /* Must be protected by mem_hotplug_begin() */
964 int __ref
online_pages(unsigned long pfn
, unsigned long nr_pages
, int online_type
)
967 unsigned long onlined_pages
= 0;
969 int need_zonelists_rebuild
= 0;
972 struct memory_notify arg
;
974 nid
= pfn_to_nid(pfn
);
975 if (!allow_online_pfn_range(nid
, pfn
, nr_pages
, online_type
))
978 /* associate pfn range with the zone */
979 zone
= move_pfn_range(online_type
, nid
, pfn
, nr_pages
);
982 arg
.nr_pages
= nr_pages
;
983 node_states_check_changes_online(nr_pages
, zone
, &arg
);
985 ret
= memory_notify(MEM_GOING_ONLINE
, &arg
);
986 ret
= notifier_to_errno(ret
);
988 goto failed_addition
;
991 * If this zone is not populated, then it is not in zonelist.
992 * This means the page allocator ignores this zone.
993 * So, zonelist must be updated after online.
995 mutex_lock(&zonelists_mutex
);
996 if (!populated_zone(zone
)) {
997 need_zonelists_rebuild
= 1;
998 build_all_zonelists(NULL
, zone
);
1001 ret
= walk_system_ram_range(pfn
, nr_pages
, &onlined_pages
,
1002 online_pages_range
);
1004 if (need_zonelists_rebuild
)
1005 zone_pcp_reset(zone
);
1006 mutex_unlock(&zonelists_mutex
);
1007 goto failed_addition
;
1010 zone
->present_pages
+= onlined_pages
;
1012 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
1013 zone
->zone_pgdat
->node_present_pages
+= onlined_pages
;
1014 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
1016 if (onlined_pages
) {
1017 node_states_set_node(nid
, &arg
);
1018 if (need_zonelists_rebuild
)
1019 build_all_zonelists(NULL
, NULL
);
1021 zone_pcp_update(zone
);
1024 mutex_unlock(&zonelists_mutex
);
1026 init_per_zone_wmark_min();
1028 if (onlined_pages
) {
1033 vm_total_pages
= nr_free_pagecache_pages();
1035 writeback_set_ratelimit();
1038 memory_notify(MEM_ONLINE
, &arg
);
1042 pr_debug("online_pages [mem %#010llx-%#010llx] failed\n",
1043 (unsigned long long) pfn
<< PAGE_SHIFT
,
1044 (((unsigned long long) pfn
+ nr_pages
) << PAGE_SHIFT
) - 1);
1045 memory_notify(MEM_CANCEL_ONLINE
, &arg
);
1048 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
1050 static void reset_node_present_pages(pg_data_t
*pgdat
)
1054 for (z
= pgdat
->node_zones
; z
< pgdat
->node_zones
+ MAX_NR_ZONES
; z
++)
1055 z
->present_pages
= 0;
1057 pgdat
->node_present_pages
= 0;
1060 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
1061 static pg_data_t __ref
*hotadd_new_pgdat(int nid
, u64 start
)
1063 struct pglist_data
*pgdat
;
1064 unsigned long zones_size
[MAX_NR_ZONES
] = {0};
1065 unsigned long zholes_size
[MAX_NR_ZONES
] = {0};
1066 unsigned long start_pfn
= PFN_DOWN(start
);
1068 pgdat
= NODE_DATA(nid
);
1070 pgdat
= arch_alloc_nodedata(nid
);
1074 arch_refresh_nodedata(nid
, pgdat
);
1077 * Reset the nr_zones, order and classzone_idx before reuse.
1078 * Note that kswapd will init kswapd_classzone_idx properly
1079 * when it starts in the near future.
1081 pgdat
->nr_zones
= 0;
1082 pgdat
->kswapd_order
= 0;
1083 pgdat
->kswapd_classzone_idx
= 0;
1086 /* we can use NODE_DATA(nid) from here */
1088 /* init node's zones as empty zones, we don't have any present pages.*/
1089 free_area_init_node(nid
, zones_size
, start_pfn
, zholes_size
);
1090 pgdat
->per_cpu_nodestats
= alloc_percpu(struct per_cpu_nodestat
);
1093 * The node we allocated has no zone fallback lists. For avoiding
1094 * to access not-initialized zonelist, build here.
1096 mutex_lock(&zonelists_mutex
);
1097 build_all_zonelists(pgdat
, NULL
);
1098 mutex_unlock(&zonelists_mutex
);
1101 * zone->managed_pages is set to an approximate value in
1102 * free_area_init_core(), which will cause
1103 * /sys/device/system/node/nodeX/meminfo has wrong data.
1104 * So reset it to 0 before any memory is onlined.
1106 reset_node_managed_pages(pgdat
);
1109 * When memory is hot-added, all the memory is in offline state. So
1110 * clear all zones' present_pages because they will be updated in
1111 * online_pages() and offline_pages().
1113 reset_node_present_pages(pgdat
);
1118 static void rollback_node_hotadd(int nid
, pg_data_t
*pgdat
)
1120 arch_refresh_nodedata(nid
, NULL
);
1121 free_percpu(pgdat
->per_cpu_nodestats
);
1122 arch_free_nodedata(pgdat
);
1128 * try_online_node - online a node if offlined
1130 * called by cpu_up() to online a node without onlined memory.
1132 int try_online_node(int nid
)
1137 if (node_online(nid
))
1140 mem_hotplug_begin();
1141 pgdat
= hotadd_new_pgdat(nid
, 0);
1143 pr_err("Cannot online node %d due to NULL pgdat\n", nid
);
1147 node_set_online(nid
);
1148 ret
= register_one_node(nid
);
1151 if (pgdat
->node_zonelists
->_zonerefs
->zone
== NULL
) {
1152 mutex_lock(&zonelists_mutex
);
1153 build_all_zonelists(NULL
, NULL
);
1154 mutex_unlock(&zonelists_mutex
);
1162 static int check_hotplug_memory_range(u64 start
, u64 size
)
1164 u64 start_pfn
= PFN_DOWN(start
);
1165 u64 nr_pages
= size
>> PAGE_SHIFT
;
1167 /* Memory range must be aligned with section */
1168 if ((start_pfn
& ~PAGE_SECTION_MASK
) ||
1169 (nr_pages
% PAGES_PER_SECTION
) || (!nr_pages
)) {
1170 pr_err("Section-unaligned hotplug range: start 0x%llx, size 0x%llx\n",
1171 (unsigned long long)start
,
1172 (unsigned long long)size
);
1179 static int online_memory_block(struct memory_block
*mem
, void *arg
)
1181 return device_online(&mem
->dev
);
1184 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
1185 int __ref
add_memory_resource(int nid
, struct resource
*res
, bool online
)
1188 pg_data_t
*pgdat
= NULL
;
1194 size
= resource_size(res
);
1196 ret
= check_hotplug_memory_range(start
, size
);
1200 { /* Stupid hack to suppress address-never-null warning */
1201 void *p
= NODE_DATA(nid
);
1205 mem_hotplug_begin();
1208 * Add new range to memblock so that when hotadd_new_pgdat() is called
1209 * to allocate new pgdat, get_pfn_range_for_nid() will be able to find
1210 * this new range and calculate total pages correctly. The range will
1211 * be removed at hot-remove time.
1213 memblock_add_node(start
, size
, nid
);
1215 new_node
= !node_online(nid
);
1217 pgdat
= hotadd_new_pgdat(nid
, start
);
1223 /* call arch's memory hotadd */
1224 ret
= arch_add_memory(nid
, start
, size
, true);
1229 /* we online node here. we can't roll back from here. */
1230 node_set_online(nid
);
1233 unsigned long start_pfn
= start
>> PAGE_SHIFT
;
1234 unsigned long nr_pages
= size
>> PAGE_SHIFT
;
1236 ret
= __register_one_node(nid
);
1241 * link memory sections under this node. This is already
1242 * done when creatig memory section in register_new_memory
1243 * but that depends to have the node registered so offline
1244 * nodes have to go through register_node.
1245 * TODO clean up this mess.
1247 ret
= link_mem_sections(nid
, start_pfn
, nr_pages
);
1250 * If sysfs file of new node can't create, cpu on the node
1251 * can't be hot-added. There is no rollback way now.
1252 * So, check by BUG_ON() to catch it reluctantly..
1257 /* create new memmap entry */
1258 firmware_map_add_hotplug(start
, start
+ size
, "System RAM");
1260 /* online pages if requested */
1262 walk_memory_range(PFN_DOWN(start
), PFN_UP(start
+ size
- 1),
1263 NULL
, online_memory_block
);
1268 /* rollback pgdat allocation and others */
1270 rollback_node_hotadd(nid
, pgdat
);
1271 memblock_remove(start
, size
);
1277 EXPORT_SYMBOL_GPL(add_memory_resource
);
1279 int __ref
add_memory(int nid
, u64 start
, u64 size
)
1281 struct resource
*res
;
1284 res
= register_memory_resource(start
, size
);
1286 return PTR_ERR(res
);
1288 ret
= add_memory_resource(nid
, res
, memhp_auto_online
);
1290 release_memory_resource(res
);
1293 EXPORT_SYMBOL_GPL(add_memory
);
1295 #ifdef CONFIG_MEMORY_HOTREMOVE
1297 * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
1298 * set and the size of the free page is given by page_order(). Using this,
1299 * the function determines if the pageblock contains only free pages.
1300 * Due to buddy contraints, a free page at least the size of a pageblock will
1301 * be located at the start of the pageblock
1303 static inline int pageblock_free(struct page
*page
)
1305 return PageBuddy(page
) && page_order(page
) >= pageblock_order
;
1308 /* Return the start of the next active pageblock after a given page */
1309 static struct page
*next_active_pageblock(struct page
*page
)
1311 /* Ensure the starting page is pageblock-aligned */
1312 BUG_ON(page_to_pfn(page
) & (pageblock_nr_pages
- 1));
1314 /* If the entire pageblock is free, move to the end of free page */
1315 if (pageblock_free(page
)) {
1317 /* be careful. we don't have locks, page_order can be changed.*/
1318 order
= page_order(page
);
1319 if ((order
< MAX_ORDER
) && (order
>= pageblock_order
))
1320 return page
+ (1 << order
);
1323 return page
+ pageblock_nr_pages
;
1326 /* Checks if this range of memory is likely to be hot-removable. */
1327 bool is_mem_section_removable(unsigned long start_pfn
, unsigned long nr_pages
)
1329 struct page
*page
= pfn_to_page(start_pfn
);
1330 struct page
*end_page
= page
+ nr_pages
;
1332 /* Check the starting page of each pageblock within the range */
1333 for (; page
< end_page
; page
= next_active_pageblock(page
)) {
1334 if (!is_pageblock_removable_nolock(page
))
1339 /* All pageblocks in the memory block are likely to be hot-removable */
1344 * Confirm all pages in a range [start, end) belong to the same zone.
1345 * When true, return its valid [start, end).
1347 int test_pages_in_a_zone(unsigned long start_pfn
, unsigned long end_pfn
,
1348 unsigned long *valid_start
, unsigned long *valid_end
)
1350 unsigned long pfn
, sec_end_pfn
;
1351 unsigned long start
, end
;
1352 struct zone
*zone
= NULL
;
1355 for (pfn
= start_pfn
, sec_end_pfn
= SECTION_ALIGN_UP(start_pfn
+ 1);
1357 pfn
= sec_end_pfn
, sec_end_pfn
+= PAGES_PER_SECTION
) {
1358 /* Make sure the memory section is present first */
1359 if (!present_section_nr(pfn_to_section_nr(pfn
)))
1361 for (; pfn
< sec_end_pfn
&& pfn
< end_pfn
;
1362 pfn
+= MAX_ORDER_NR_PAGES
) {
1364 /* This is just a CONFIG_HOLES_IN_ZONE check.*/
1365 while ((i
< MAX_ORDER_NR_PAGES
) &&
1366 !pfn_valid_within(pfn
+ i
))
1368 if (i
== MAX_ORDER_NR_PAGES
|| pfn
+ i
>= end_pfn
)
1370 page
= pfn_to_page(pfn
+ i
);
1371 if (zone
&& page_zone(page
) != zone
)
1375 zone
= page_zone(page
);
1376 end
= pfn
+ MAX_ORDER_NR_PAGES
;
1381 *valid_start
= start
;
1382 *valid_end
= min(end
, end_pfn
);
1390 * Scan pfn range [start,end) to find movable/migratable pages (LRU pages,
1391 * non-lru movable pages and hugepages). We scan pfn because it's much
1392 * easier than scanning over linked list. This function returns the pfn
1393 * of the first found movable page if it's found, otherwise 0.
1395 static unsigned long scan_movable_pages(unsigned long start
, unsigned long end
)
1399 for (pfn
= start
; pfn
< end
; pfn
++) {
1400 if (pfn_valid(pfn
)) {
1401 page
= pfn_to_page(pfn
);
1404 if (__PageMovable(page
))
1406 if (PageHuge(page
)) {
1407 if (page_huge_active(page
))
1410 pfn
= round_up(pfn
+ 1,
1411 1 << compound_order(page
)) - 1;
1418 static struct page
*new_node_page(struct page
*page
, unsigned long private,
1421 gfp_t gfp_mask
= GFP_USER
| __GFP_MOVABLE
;
1422 int nid
= page_to_nid(page
);
1423 nodemask_t nmask
= node_states
[N_MEMORY
];
1424 struct page
*new_page
= NULL
;
1427 * TODO: allocate a destination hugepage from a nearest neighbor node,
1428 * accordance with memory policy of the user process if possible. For
1429 * now as a simple work-around, we use the next node for destination.
1432 return alloc_huge_page_node(page_hstate(compound_head(page
)),
1433 next_node_in(nid
, nmask
));
1435 node_clear(nid
, nmask
);
1437 if (PageHighMem(page
)
1438 || (zone_idx(page_zone(page
)) == ZONE_MOVABLE
))
1439 gfp_mask
|= __GFP_HIGHMEM
;
1441 if (!nodes_empty(nmask
))
1442 new_page
= __alloc_pages_nodemask(gfp_mask
, 0, nid
, &nmask
);
1444 new_page
= __alloc_pages(gfp_mask
, 0, nid
);
1449 #define NR_OFFLINE_AT_ONCE_PAGES (256)
1451 do_migrate_range(unsigned long start_pfn
, unsigned long end_pfn
)
1455 int move_pages
= NR_OFFLINE_AT_ONCE_PAGES
;
1456 int not_managed
= 0;
1460 for (pfn
= start_pfn
; pfn
< end_pfn
&& move_pages
> 0; pfn
++) {
1461 if (!pfn_valid(pfn
))
1463 page
= pfn_to_page(pfn
);
1465 if (PageHuge(page
)) {
1466 struct page
*head
= compound_head(page
);
1467 pfn
= page_to_pfn(head
) + (1<<compound_order(head
)) - 1;
1468 if (compound_order(head
) > PFN_SECTION_SHIFT
) {
1472 if (isolate_huge_page(page
, &source
))
1473 move_pages
-= 1 << compound_order(head
);
1477 if (!get_page_unless_zero(page
))
1480 * We can skip free pages. And we can deal with pages on
1481 * LRU and non-lru movable pages.
1484 ret
= isolate_lru_page(page
);
1486 ret
= isolate_movable_page(page
, ISOLATE_UNEVICTABLE
);
1487 if (!ret
) { /* Success */
1489 list_add_tail(&page
->lru
, &source
);
1491 if (!__PageMovable(page
))
1492 inc_node_page_state(page
, NR_ISOLATED_ANON
+
1493 page_is_file_cache(page
));
1496 #ifdef CONFIG_DEBUG_VM
1497 pr_alert("failed to isolate pfn %lx\n", pfn
);
1498 dump_page(page
, "isolation failed");
1501 /* Because we don't have big zone->lock. we should
1502 check this again here. */
1503 if (page_count(page
)) {
1510 if (!list_empty(&source
)) {
1512 putback_movable_pages(&source
);
1516 /* Allocate a new page from the nearest neighbor node */
1517 ret
= migrate_pages(&source
, new_node_page
, NULL
, 0,
1518 MIGRATE_SYNC
, MR_MEMORY_HOTPLUG
);
1520 putback_movable_pages(&source
);
1527 * remove from free_area[] and mark all as Reserved.
1530 offline_isolated_pages_cb(unsigned long start
, unsigned long nr_pages
,
1533 __offline_isolated_pages(start
, start
+ nr_pages
);
1538 offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
1540 walk_system_ram_range(start_pfn
, end_pfn
- start_pfn
, NULL
,
1541 offline_isolated_pages_cb
);
1545 * Check all pages in range, recoreded as memory resource, are isolated.
1548 check_pages_isolated_cb(unsigned long start_pfn
, unsigned long nr_pages
,
1552 long offlined
= *(long *)data
;
1553 ret
= test_pages_isolated(start_pfn
, start_pfn
+ nr_pages
, true);
1554 offlined
= nr_pages
;
1556 *(long *)data
+= offlined
;
1561 check_pages_isolated(unsigned long start_pfn
, unsigned long end_pfn
)
1566 ret
= walk_system_ram_range(start_pfn
, end_pfn
- start_pfn
, &offlined
,
1567 check_pages_isolated_cb
);
1569 offlined
= (long)ret
;
1573 static int __init
cmdline_parse_movable_node(char *p
)
1575 movable_node_enabled
= true;
1578 early_param("movable_node", cmdline_parse_movable_node
);
1580 /* check which state of node_states will be changed when offline memory */
1581 static void node_states_check_changes_offline(unsigned long nr_pages
,
1582 struct zone
*zone
, struct memory_notify
*arg
)
1584 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
1585 unsigned long present_pages
= 0;
1586 enum zone_type zt
, zone_last
= ZONE_NORMAL
;
1589 * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
1590 * contains nodes which have zones of 0...ZONE_NORMAL,
1591 * set zone_last to ZONE_NORMAL.
1593 * If we don't have HIGHMEM nor movable node,
1594 * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
1595 * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
1597 if (N_MEMORY
== N_NORMAL_MEMORY
)
1598 zone_last
= ZONE_MOVABLE
;
1601 * check whether node_states[N_NORMAL_MEMORY] will be changed.
1602 * If the memory to be offline is in a zone of 0...zone_last,
1603 * and it is the last present memory, 0...zone_last will
1604 * become empty after offline , thus we can determind we will
1605 * need to clear the node from node_states[N_NORMAL_MEMORY].
1607 for (zt
= 0; zt
<= zone_last
; zt
++)
1608 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1609 if (zone_idx(zone
) <= zone_last
&& nr_pages
>= present_pages
)
1610 arg
->status_change_nid_normal
= zone_to_nid(zone
);
1612 arg
->status_change_nid_normal
= -1;
1614 #ifdef CONFIG_HIGHMEM
1616 * If we have movable node, node_states[N_HIGH_MEMORY]
1617 * contains nodes which have zones of 0...ZONE_HIGHMEM,
1618 * set zone_last to ZONE_HIGHMEM.
1620 * If we don't have movable node, node_states[N_NORMAL_MEMORY]
1621 * contains nodes which have zones of 0...ZONE_MOVABLE,
1622 * set zone_last to ZONE_MOVABLE.
1624 zone_last
= ZONE_HIGHMEM
;
1625 if (N_MEMORY
== N_HIGH_MEMORY
)
1626 zone_last
= ZONE_MOVABLE
;
1628 for (; zt
<= zone_last
; zt
++)
1629 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1630 if (zone_idx(zone
) <= zone_last
&& nr_pages
>= present_pages
)
1631 arg
->status_change_nid_high
= zone_to_nid(zone
);
1633 arg
->status_change_nid_high
= -1;
1635 arg
->status_change_nid_high
= arg
->status_change_nid_normal
;
1639 * node_states[N_HIGH_MEMORY] contains nodes which have 0...ZONE_MOVABLE
1641 zone_last
= ZONE_MOVABLE
;
1644 * check whether node_states[N_HIGH_MEMORY] will be changed
1645 * If we try to offline the last present @nr_pages from the node,
1646 * we can determind we will need to clear the node from
1647 * node_states[N_HIGH_MEMORY].
1649 for (; zt
<= zone_last
; zt
++)
1650 present_pages
+= pgdat
->node_zones
[zt
].present_pages
;
1651 if (nr_pages
>= present_pages
)
1652 arg
->status_change_nid
= zone_to_nid(zone
);
1654 arg
->status_change_nid
= -1;
1657 static void node_states_clear_node(int node
, struct memory_notify
*arg
)
1659 if (arg
->status_change_nid_normal
>= 0)
1660 node_clear_state(node
, N_NORMAL_MEMORY
);
1662 if ((N_MEMORY
!= N_NORMAL_MEMORY
) &&
1663 (arg
->status_change_nid_high
>= 0))
1664 node_clear_state(node
, N_HIGH_MEMORY
);
1666 if ((N_MEMORY
!= N_HIGH_MEMORY
) &&
1667 (arg
->status_change_nid
>= 0))
1668 node_clear_state(node
, N_MEMORY
);
1671 static int __ref
__offline_pages(unsigned long start_pfn
,
1672 unsigned long end_pfn
, unsigned long timeout
)
1674 unsigned long pfn
, nr_pages
, expire
;
1675 long offlined_pages
;
1676 int ret
, drain
, retry_max
, node
;
1677 unsigned long flags
;
1678 unsigned long valid_start
, valid_end
;
1680 struct memory_notify arg
;
1682 /* at least, alignment against pageblock is necessary */
1683 if (!IS_ALIGNED(start_pfn
, pageblock_nr_pages
))
1685 if (!IS_ALIGNED(end_pfn
, pageblock_nr_pages
))
1687 /* This makes hotplug much easier...and readable.
1688 we assume this for now. .*/
1689 if (!test_pages_in_a_zone(start_pfn
, end_pfn
, &valid_start
, &valid_end
))
1692 zone
= page_zone(pfn_to_page(valid_start
));
1693 node
= zone_to_nid(zone
);
1694 nr_pages
= end_pfn
- start_pfn
;
1696 /* set above range as isolated */
1697 ret
= start_isolate_page_range(start_pfn
, end_pfn
,
1698 MIGRATE_MOVABLE
, true);
1702 arg
.start_pfn
= start_pfn
;
1703 arg
.nr_pages
= nr_pages
;
1704 node_states_check_changes_offline(nr_pages
, zone
, &arg
);
1706 ret
= memory_notify(MEM_GOING_OFFLINE
, &arg
);
1707 ret
= notifier_to_errno(ret
);
1709 goto failed_removal
;
1712 expire
= jiffies
+ timeout
;
1716 /* start memory hot removal */
1718 if (time_after(jiffies
, expire
))
1719 goto failed_removal
;
1721 if (signal_pending(current
))
1722 goto failed_removal
;
1725 lru_add_drain_all();
1727 drain_all_pages(zone
);
1730 pfn
= scan_movable_pages(start_pfn
, end_pfn
);
1731 if (pfn
) { /* We have movable pages */
1732 ret
= do_migrate_range(pfn
, end_pfn
);
1738 if (--retry_max
== 0)
1739 goto failed_removal
;
1745 /* drain all zone's lru pagevec, this is asynchronous... */
1746 lru_add_drain_all();
1748 /* drain pcp pages, this is synchronous. */
1749 drain_all_pages(zone
);
1751 * dissolve free hugepages in the memory block before doing offlining
1752 * actually in order to make hugetlbfs's object counting consistent.
1754 ret
= dissolve_free_huge_pages(start_pfn
, end_pfn
);
1756 goto failed_removal
;
1758 offlined_pages
= check_pages_isolated(start_pfn
, end_pfn
);
1759 if (offlined_pages
< 0) {
1761 goto failed_removal
;
1763 pr_info("Offlined Pages %ld\n", offlined_pages
);
1764 /* Ok, all of our target is isolated.
1765 We cannot do rollback at this point. */
1766 offline_isolated_pages(start_pfn
, end_pfn
);
1767 /* reset pagetype flags and makes migrate type to be MOVABLE */
1768 undo_isolate_page_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
);
1769 /* removal success */
1770 adjust_managed_page_count(pfn_to_page(start_pfn
), -offlined_pages
);
1771 zone
->present_pages
-= offlined_pages
;
1773 pgdat_resize_lock(zone
->zone_pgdat
, &flags
);
1774 zone
->zone_pgdat
->node_present_pages
-= offlined_pages
;
1775 pgdat_resize_unlock(zone
->zone_pgdat
, &flags
);
1777 init_per_zone_wmark_min();
1779 if (!populated_zone(zone
)) {
1780 zone_pcp_reset(zone
);
1781 mutex_lock(&zonelists_mutex
);
1782 build_all_zonelists(NULL
, NULL
);
1783 mutex_unlock(&zonelists_mutex
);
1785 zone_pcp_update(zone
);
1787 node_states_clear_node(node
, &arg
);
1788 if (arg
.status_change_nid
>= 0) {
1790 kcompactd_stop(node
);
1793 vm_total_pages
= nr_free_pagecache_pages();
1794 writeback_set_ratelimit();
1796 memory_notify(MEM_OFFLINE
, &arg
);
1800 pr_debug("memory offlining [mem %#010llx-%#010llx] failed\n",
1801 (unsigned long long) start_pfn
<< PAGE_SHIFT
,
1802 ((unsigned long long) end_pfn
<< PAGE_SHIFT
) - 1);
1803 memory_notify(MEM_CANCEL_OFFLINE
, &arg
);
1804 /* pushback to free area */
1805 undo_isolate_page_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
);
1809 /* Must be protected by mem_hotplug_begin() */
1810 int offline_pages(unsigned long start_pfn
, unsigned long nr_pages
)
1812 return __offline_pages(start_pfn
, start_pfn
+ nr_pages
, 120 * HZ
);
1814 #endif /* CONFIG_MEMORY_HOTREMOVE */
1817 * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn)
1818 * @start_pfn: start pfn of the memory range
1819 * @end_pfn: end pfn of the memory range
1820 * @arg: argument passed to func
1821 * @func: callback for each memory section walked
1823 * This function walks through all present mem sections in range
1824 * [start_pfn, end_pfn) and call func on each mem section.
1826 * Returns the return value of func.
1828 int walk_memory_range(unsigned long start_pfn
, unsigned long end_pfn
,
1829 void *arg
, int (*func
)(struct memory_block
*, void *))
1831 struct memory_block
*mem
= NULL
;
1832 struct mem_section
*section
;
1833 unsigned long pfn
, section_nr
;
1836 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
1837 section_nr
= pfn_to_section_nr(pfn
);
1838 if (!present_section_nr(section_nr
))
1841 section
= __nr_to_section(section_nr
);
1842 /* same memblock? */
1844 if ((section_nr
>= mem
->start_section_nr
) &&
1845 (section_nr
<= mem
->end_section_nr
))
1848 mem
= find_memory_block_hinted(section
, mem
);
1852 ret
= func(mem
, arg
);
1854 kobject_put(&mem
->dev
.kobj
);
1860 kobject_put(&mem
->dev
.kobj
);
1865 #ifdef CONFIG_MEMORY_HOTREMOVE
1866 static int check_memblock_offlined_cb(struct memory_block
*mem
, void *arg
)
1868 int ret
= !is_memblock_offlined(mem
);
1870 if (unlikely(ret
)) {
1871 phys_addr_t beginpa
, endpa
;
1873 beginpa
= PFN_PHYS(section_nr_to_pfn(mem
->start_section_nr
));
1874 endpa
= PFN_PHYS(section_nr_to_pfn(mem
->end_section_nr
+ 1))-1;
1875 pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n",
1882 static int check_cpu_on_node(pg_data_t
*pgdat
)
1886 for_each_present_cpu(cpu
) {
1887 if (cpu_to_node(cpu
) == pgdat
->node_id
)
1889 * the cpu on this node isn't removed, and we can't
1890 * offline this node.
1898 static void unmap_cpu_on_node(pg_data_t
*pgdat
)
1900 #ifdef CONFIG_ACPI_NUMA
1903 for_each_possible_cpu(cpu
)
1904 if (cpu_to_node(cpu
) == pgdat
->node_id
)
1905 numa_clear_node(cpu
);
1909 static int check_and_unmap_cpu_on_node(pg_data_t
*pgdat
)
1913 ret
= check_cpu_on_node(pgdat
);
1918 * the node will be offlined when we come here, so we can clear
1919 * the cpu_to_node() now.
1922 unmap_cpu_on_node(pgdat
);
1929 * Offline a node if all memory sections and cpus of the node are removed.
1931 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
1932 * and online/offline operations before this call.
1934 void try_offline_node(int nid
)
1936 pg_data_t
*pgdat
= NODE_DATA(nid
);
1937 unsigned long start_pfn
= pgdat
->node_start_pfn
;
1938 unsigned long end_pfn
= start_pfn
+ pgdat
->node_spanned_pages
;
1941 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
1942 unsigned long section_nr
= pfn_to_section_nr(pfn
);
1944 if (!present_section_nr(section_nr
))
1947 if (pfn_to_nid(pfn
) != nid
)
1951 * some memory sections of this node are not removed, and we
1952 * can't offline node now.
1957 if (check_and_unmap_cpu_on_node(pgdat
))
1961 * all memory/cpu of this node are removed, we can offline this
1964 node_set_offline(nid
);
1965 unregister_one_node(nid
);
1967 EXPORT_SYMBOL(try_offline_node
);
1972 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
1973 * and online/offline operations before this call, as required by
1974 * try_offline_node().
1976 void __ref
remove_memory(int nid
, u64 start
, u64 size
)
1980 BUG_ON(check_hotplug_memory_range(start
, size
));
1982 mem_hotplug_begin();
1985 * All memory blocks must be offlined before removing memory. Check
1986 * whether all memory blocks in question are offline and trigger a BUG()
1987 * if this is not the case.
1989 ret
= walk_memory_range(PFN_DOWN(start
), PFN_UP(start
+ size
- 1), NULL
,
1990 check_memblock_offlined_cb
);
1994 /* remove memmap entry */
1995 firmware_map_remove(start
, start
+ size
, "System RAM");
1996 memblock_free(start
, size
);
1997 memblock_remove(start
, size
);
1999 arch_remove_memory(start
, size
);
2001 try_offline_node(nid
);
2005 EXPORT_SYMBOL_GPL(remove_memory
);
2006 #endif /* CONFIG_MEMORY_HOTREMOVE */