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1 | /* |
2 | * linux/mm/memory_hotplug.c |
3 | * |
4 | * Copyright (C) |
5 | */ |
6 | |
7 | #include <linux/stddef.h> |
8 | #include <linux/mm.h> |
9 | #include <linux/swap.h> |
10 | #include <linux/interrupt.h> |
11 | #include <linux/pagemap.h> |
12 | #include <linux/compiler.h> |
13 | #include <linux/export.h> |
14 | #include <linux/pagevec.h> |
15 | #include <linux/writeback.h> |
16 | #include <linux/slab.h> |
17 | #include <linux/sysctl.h> |
18 | #include <linux/cpu.h> |
19 | #include <linux/memory.h> |
20 | #include <linux/memory_hotplug.h> |
21 | #include <linux/highmem.h> |
22 | #include <linux/vmalloc.h> |
23 | #include <linux/ioport.h> |
24 | #include <linux/delay.h> |
25 | #include <linux/migrate.h> |
26 | #include <linux/page-isolation.h> |
27 | #include <linux/pfn.h> |
28 | #include <linux/suspend.h> |
29 | #include <linux/mm_inline.h> |
30 | #include <linux/firmware-map.h> |
31 | #include <linux/stop_machine.h> |
32 | #include <linux/hugetlb.h> |
33 | #include <linux/memblock.h> |
34 | |
35 | #include <asm/tlbflush.h> |
36 | |
37 | #include "internal.h" |
38 | |
39 | /* |
40 | * online_page_callback contains pointer to current page onlining function. |
41 | * Initially it is generic_online_page(). If it is required it could be |
42 | * changed by calling set_online_page_callback() for callback registration |
43 | * and restore_online_page_callback() for generic callback restore. |
44 | */ |
45 | |
46 | static void generic_online_page(struct page *page); |
47 | |
48 | static online_page_callback_t online_page_callback = generic_online_page; |
49 | static DEFINE_MUTEX(online_page_callback_lock); |
50 | |
51 | /* The same as the cpu_hotplug lock, but for memory hotplug. */ |
52 | static struct { |
53 | struct task_struct *active_writer; |
54 | struct mutex lock; /* Synchronizes accesses to refcount, */ |
55 | /* |
56 | * Also blocks the new readers during |
57 | * an ongoing mem hotplug operation. |
58 | */ |
59 | int refcount; |
60 | |
61 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
62 | struct lockdep_map dep_map; |
63 | #endif |
64 | } mem_hotplug = { |
65 | .active_writer = NULL, |
66 | .lock = __MUTEX_INITIALIZER(mem_hotplug.lock), |
67 | .refcount = 0, |
68 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
69 | .dep_map = {.name = "mem_hotplug.lock" }, |
70 | #endif |
71 | }; |
72 | |
73 | /* Lockdep annotations for get/put_online_mems() and mem_hotplug_begin/end() */ |
74 | #define memhp_lock_acquire_read() lock_map_acquire_read(&mem_hotplug.dep_map) |
75 | #define memhp_lock_acquire() lock_map_acquire(&mem_hotplug.dep_map) |
76 | #define memhp_lock_release() lock_map_release(&mem_hotplug.dep_map) |
77 | |
78 | void get_online_mems(void) |
79 | { |
80 | might_sleep(); |
81 | if (mem_hotplug.active_writer == current) |
82 | return; |
83 | memhp_lock_acquire_read(); |
84 | mutex_lock(&mem_hotplug.lock); |
85 | mem_hotplug.refcount++; |
86 | mutex_unlock(&mem_hotplug.lock); |
87 | |
88 | } |
89 | |
90 | void put_online_mems(void) |
91 | { |
92 | if (mem_hotplug.active_writer == current) |
93 | return; |
94 | mutex_lock(&mem_hotplug.lock); |
95 | |
96 | if (WARN_ON(!mem_hotplug.refcount)) |
97 | mem_hotplug.refcount++; /* try to fix things up */ |
98 | |
99 | if (!--mem_hotplug.refcount && unlikely(mem_hotplug.active_writer)) |
100 | wake_up_process(mem_hotplug.active_writer); |
101 | mutex_unlock(&mem_hotplug.lock); |
102 | memhp_lock_release(); |
103 | |
104 | } |
105 | |
106 | static void mem_hotplug_begin(void) |
107 | { |
108 | mem_hotplug.active_writer = current; |
109 | |
110 | memhp_lock_acquire(); |
111 | for (;;) { |
112 | mutex_lock(&mem_hotplug.lock); |
113 | if (likely(!mem_hotplug.refcount)) |
114 | break; |
115 | __set_current_state(TASK_UNINTERRUPTIBLE); |
116 | mutex_unlock(&mem_hotplug.lock); |
117 | schedule(); |
118 | } |
119 | } |
120 | |
121 | static void mem_hotplug_done(void) |
122 | { |
123 | mem_hotplug.active_writer = NULL; |
124 | mutex_unlock(&mem_hotplug.lock); |
125 | memhp_lock_release(); |
126 | } |
127 | |
128 | /* add this memory to iomem resource */ |
129 | static struct resource *register_memory_resource(u64 start, u64 size) |
130 | { |
131 | struct resource *res; |
132 | res = kzalloc(sizeof(struct resource), GFP_KERNEL); |
133 | BUG_ON(!res); |
134 | |
135 | res->name = "System RAM"; |
136 | res->start = start; |
137 | res->end = start + size - 1; |
138 | res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; |
139 | if (request_resource(&iomem_resource, res) < 0) { |
140 | pr_debug("System RAM resource %pR cannot be added\n", res); |
141 | kfree(res); |
142 | res = NULL; |
143 | } |
144 | return res; |
145 | } |
146 | |
147 | static void release_memory_resource(struct resource *res) |
148 | { |
149 | if (!res) |
150 | return; |
151 | release_resource(res); |
152 | kfree(res); |
153 | return; |
154 | } |
155 | |
156 | #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE |
157 | void get_page_bootmem(unsigned long info, struct page *page, |
158 | unsigned long type) |
159 | { |
160 | page->lru.next = (struct list_head *) type; |
161 | SetPagePrivate(page); |
162 | set_page_private(page, info); |
163 | atomic_inc(&page->_count); |
164 | } |
165 | |
166 | void put_page_bootmem(struct page *page) |
167 | { |
168 | unsigned long type; |
169 | |
170 | type = (unsigned long) page->lru.next; |
171 | BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || |
172 | type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE); |
173 | |
174 | if (atomic_dec_return(&page->_count) == 1) { |
175 | ClearPagePrivate(page); |
176 | set_page_private(page, 0); |
177 | INIT_LIST_HEAD(&page->lru); |
178 | free_reserved_page(page); |
179 | } |
180 | } |
181 | |
182 | #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE |
183 | #ifndef CONFIG_SPARSEMEM_VMEMMAP |
184 | static void register_page_bootmem_info_section(unsigned long start_pfn) |
185 | { |
186 | unsigned long *usemap, mapsize, section_nr, i; |
187 | struct mem_section *ms; |
188 | struct page *page, *memmap; |
189 | |
190 | section_nr = pfn_to_section_nr(start_pfn); |
191 | ms = __nr_to_section(section_nr); |
192 | |
193 | /* Get section's memmap address */ |
194 | memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); |
195 | |
196 | /* |
197 | * Get page for the memmap's phys address |
198 | * XXX: need more consideration for sparse_vmemmap... |
199 | */ |
200 | page = virt_to_page(memmap); |
201 | mapsize = sizeof(struct page) * PAGES_PER_SECTION; |
202 | mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT; |
203 | |
204 | /* remember memmap's page */ |
205 | for (i = 0; i < mapsize; i++, page++) |
206 | get_page_bootmem(section_nr, page, SECTION_INFO); |
207 | |
208 | usemap = __nr_to_section(section_nr)->pageblock_flags; |
209 | page = virt_to_page(usemap); |
210 | |
211 | mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT; |
212 | |
213 | for (i = 0; i < mapsize; i++, page++) |
214 | get_page_bootmem(section_nr, page, MIX_SECTION_INFO); |
215 | |
216 | } |
217 | #else /* CONFIG_SPARSEMEM_VMEMMAP */ |
218 | static void register_page_bootmem_info_section(unsigned long start_pfn) |
219 | { |
220 | unsigned long *usemap, mapsize, section_nr, i; |
221 | struct mem_section *ms; |
222 | struct page *page, *memmap; |
223 | |
224 | if (!pfn_valid(start_pfn)) |
225 | return; |
226 | |
227 | section_nr = pfn_to_section_nr(start_pfn); |
228 | ms = __nr_to_section(section_nr); |
229 | |
230 | memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); |
231 | |
232 | register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION); |
233 | |
234 | usemap = __nr_to_section(section_nr)->pageblock_flags; |
235 | page = virt_to_page(usemap); |
236 | |
237 | mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT; |
238 | |
239 | for (i = 0; i < mapsize; i++, page++) |
240 | get_page_bootmem(section_nr, page, MIX_SECTION_INFO); |
241 | } |
242 | #endif /* !CONFIG_SPARSEMEM_VMEMMAP */ |
243 | |
244 | void register_page_bootmem_info_node(struct pglist_data *pgdat) |
245 | { |
246 | unsigned long i, pfn, end_pfn, nr_pages; |
247 | int node = pgdat->node_id; |
248 | struct page *page; |
249 | struct zone *zone; |
250 | |
251 | nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT; |
252 | page = virt_to_page(pgdat); |
253 | |
254 | for (i = 0; i < nr_pages; i++, page++) |
255 | get_page_bootmem(node, page, NODE_INFO); |
256 | |
257 | zone = &pgdat->node_zones[0]; |
258 | for (; zone < pgdat->node_zones + MAX_NR_ZONES - 1; zone++) { |
259 | if (zone_is_initialized(zone)) { |
260 | nr_pages = zone->wait_table_hash_nr_entries |
261 | * sizeof(wait_queue_head_t); |
262 | nr_pages = PAGE_ALIGN(nr_pages) >> PAGE_SHIFT; |
263 | page = virt_to_page(zone->wait_table); |
264 | |
265 | for (i = 0; i < nr_pages; i++, page++) |
266 | get_page_bootmem(node, page, NODE_INFO); |
267 | } |
268 | } |
269 | |
270 | pfn = pgdat->node_start_pfn; |
271 | end_pfn = pgdat_end_pfn(pgdat); |
272 | |
273 | /* register section info */ |
274 | for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { |
275 | /* |
276 | * Some platforms can assign the same pfn to multiple nodes - on |
277 | * node0 as well as nodeN. To avoid registering a pfn against |
278 | * multiple nodes we check that this pfn does not already |
279 | * reside in some other nodes. |
280 | */ |
281 | if (pfn_valid(pfn) && (pfn_to_nid(pfn) == node)) |
282 | register_page_bootmem_info_section(pfn); |
283 | } |
284 | } |
285 | #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */ |
286 | |
287 | static void grow_zone_span(struct zone *zone, unsigned long start_pfn, |
288 | unsigned long end_pfn) |
289 | { |
290 | unsigned long old_zone_end_pfn; |
291 | |
292 | zone_span_writelock(zone); |
293 | |
294 | old_zone_end_pfn = zone_end_pfn(zone); |
295 | if (zone_is_empty(zone) || start_pfn < zone->zone_start_pfn) |
296 | zone->zone_start_pfn = start_pfn; |
297 | |
298 | zone->spanned_pages = max(old_zone_end_pfn, end_pfn) - |
299 | zone->zone_start_pfn; |
300 | |
301 | zone_span_writeunlock(zone); |
302 | } |
303 | |
304 | static void resize_zone(struct zone *zone, unsigned long start_pfn, |
305 | unsigned long end_pfn) |
306 | { |
307 | zone_span_writelock(zone); |
308 | |
309 | if (end_pfn - start_pfn) { |
310 | zone->zone_start_pfn = start_pfn; |
311 | zone->spanned_pages = end_pfn - start_pfn; |
312 | } else { |
313 | /* |
314 | * make it consist as free_area_init_core(), |
315 | * if spanned_pages = 0, then keep start_pfn = 0 |
316 | */ |
317 | zone->zone_start_pfn = 0; |
318 | zone->spanned_pages = 0; |
319 | } |
320 | |
321 | zone_span_writeunlock(zone); |
322 | } |
323 | |
324 | static void fix_zone_id(struct zone *zone, unsigned long start_pfn, |
325 | unsigned long end_pfn) |
326 | { |
327 | enum zone_type zid = zone_idx(zone); |
328 | int nid = zone->zone_pgdat->node_id; |
329 | unsigned long pfn; |
330 | |
331 | for (pfn = start_pfn; pfn < end_pfn; pfn++) |
332 | set_page_links(pfn_to_page(pfn), zid, nid, pfn); |
333 | } |
334 | |
335 | /* Can fail with -ENOMEM from allocating a wait table with vmalloc() or |
336 | * alloc_bootmem_node_nopanic()/memblock_virt_alloc_node_nopanic() */ |
337 | static int __ref ensure_zone_is_initialized(struct zone *zone, |
338 | unsigned long start_pfn, unsigned long num_pages) |
339 | { |
340 | if (!zone_is_initialized(zone)) |
341 | return init_currently_empty_zone(zone, start_pfn, num_pages, |
342 | MEMMAP_HOTPLUG); |
343 | return 0; |
344 | } |
345 | |
346 | static int __meminit move_pfn_range_left(struct zone *z1, struct zone *z2, |
347 | unsigned long start_pfn, unsigned long end_pfn) |
348 | { |
349 | int ret; |
350 | unsigned long flags; |
351 | unsigned long z1_start_pfn; |
352 | |
353 | ret = ensure_zone_is_initialized(z1, start_pfn, end_pfn - start_pfn); |
354 | if (ret) |
355 | return ret; |
356 | |
357 | pgdat_resize_lock(z1->zone_pgdat, &flags); |
358 | |
359 | /* can't move pfns which are higher than @z2 */ |
360 | if (end_pfn > zone_end_pfn(z2)) |
361 | goto out_fail; |
362 | /* the move out part must be at the left most of @z2 */ |
363 | if (start_pfn > z2->zone_start_pfn) |
364 | goto out_fail; |
365 | /* must included/overlap */ |
366 | if (end_pfn <= z2->zone_start_pfn) |
367 | goto out_fail; |
368 | |
369 | /* use start_pfn for z1's start_pfn if z1 is empty */ |
370 | if (!zone_is_empty(z1)) |
371 | z1_start_pfn = z1->zone_start_pfn; |
372 | else |
373 | z1_start_pfn = start_pfn; |
374 | |
375 | resize_zone(z1, z1_start_pfn, end_pfn); |
376 | resize_zone(z2, end_pfn, zone_end_pfn(z2)); |
377 | |
378 | pgdat_resize_unlock(z1->zone_pgdat, &flags); |
379 | |
380 | fix_zone_id(z1, start_pfn, end_pfn); |
381 | |
382 | return 0; |
383 | out_fail: |
384 | pgdat_resize_unlock(z1->zone_pgdat, &flags); |
385 | return -1; |
386 | } |
387 | |
388 | static int __meminit move_pfn_range_right(struct zone *z1, struct zone *z2, |
389 | unsigned long start_pfn, unsigned long end_pfn) |
390 | { |
391 | int ret; |
392 | unsigned long flags; |
393 | unsigned long z2_end_pfn; |
394 | |
395 | ret = ensure_zone_is_initialized(z2, start_pfn, end_pfn - start_pfn); |
396 | if (ret) |
397 | return ret; |
398 | |
399 | pgdat_resize_lock(z1->zone_pgdat, &flags); |
400 | |
401 | /* can't move pfns which are lower than @z1 */ |
402 | if (z1->zone_start_pfn > start_pfn) |
403 | goto out_fail; |
404 | /* the move out part mast at the right most of @z1 */ |
405 | if (zone_end_pfn(z1) > end_pfn) |
406 | goto out_fail; |
407 | /* must included/overlap */ |
408 | if (start_pfn >= zone_end_pfn(z1)) |
409 | goto out_fail; |
410 | |
411 | /* use end_pfn for z2's end_pfn if z2 is empty */ |
412 | if (!zone_is_empty(z2)) |
413 | z2_end_pfn = zone_end_pfn(z2); |
414 | else |
415 | z2_end_pfn = end_pfn; |
416 | |
417 | resize_zone(z1, z1->zone_start_pfn, start_pfn); |
418 | resize_zone(z2, start_pfn, z2_end_pfn); |
419 | |
420 | pgdat_resize_unlock(z1->zone_pgdat, &flags); |
421 | |
422 | fix_zone_id(z2, start_pfn, end_pfn); |
423 | |
424 | return 0; |
425 | out_fail: |
426 | pgdat_resize_unlock(z1->zone_pgdat, &flags); |
427 | return -1; |
428 | } |
429 | |
430 | static void grow_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn, |
431 | unsigned long end_pfn) |
432 | { |
433 | unsigned long old_pgdat_end_pfn = pgdat_end_pfn(pgdat); |
434 | |
435 | if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn) |
436 | pgdat->node_start_pfn = start_pfn; |
437 | |
438 | pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) - |
439 | pgdat->node_start_pfn; |
440 | } |
441 | |
442 | static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn) |
443 | { |
444 | struct pglist_data *pgdat = zone->zone_pgdat; |
445 | int nr_pages = PAGES_PER_SECTION; |
446 | int nid = pgdat->node_id; |
447 | int zone_type; |
448 | unsigned long flags; |
449 | int ret; |
450 | |
451 | zone_type = zone - pgdat->node_zones; |
452 | ret = ensure_zone_is_initialized(zone, phys_start_pfn, nr_pages); |
453 | if (ret) |
454 | return ret; |
455 | |
456 | pgdat_resize_lock(zone->zone_pgdat, &flags); |
457 | grow_zone_span(zone, phys_start_pfn, phys_start_pfn + nr_pages); |
458 | grow_pgdat_span(zone->zone_pgdat, phys_start_pfn, |
459 | phys_start_pfn + nr_pages); |
460 | pgdat_resize_unlock(zone->zone_pgdat, &flags); |
461 | memmap_init_zone(nr_pages, nid, zone_type, |
462 | phys_start_pfn, MEMMAP_HOTPLUG); |
463 | return 0; |
464 | } |
465 | |
466 | static int __meminit __add_section(int nid, struct zone *zone, |
467 | unsigned long phys_start_pfn) |
468 | { |
469 | int ret; |
470 | |
471 | if (pfn_valid(phys_start_pfn)) |
472 | return -EEXIST; |
473 | |
474 | ret = sparse_add_one_section(zone, phys_start_pfn); |
475 | |
476 | if (ret < 0) |
477 | return ret; |
478 | |
479 | ret = __add_zone(zone, phys_start_pfn); |
480 | |
481 | if (ret < 0) |
482 | return ret; |
483 | |
484 | return register_new_memory(nid, __pfn_to_section(phys_start_pfn)); |
485 | } |
486 | |
487 | /* |
488 | * Reasonably generic function for adding memory. It is |
489 | * expected that archs that support memory hotplug will |
490 | * call this function after deciding the zone to which to |
491 | * add the new pages. |
492 | */ |
493 | int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn, |
494 | unsigned long nr_pages) |
495 | { |
496 | unsigned long i; |
497 | int err = 0; |
498 | int start_sec, end_sec; |
499 | /* during initialize mem_map, align hot-added range to section */ |
500 | start_sec = pfn_to_section_nr(phys_start_pfn); |
501 | end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1); |
502 | |
503 | for (i = start_sec; i <= end_sec; i++) { |
504 | err = __add_section(nid, zone, i << PFN_SECTION_SHIFT); |
505 | |
506 | /* |
507 | * EEXIST is finally dealt with by ioresource collision |
508 | * check. see add_memory() => register_memory_resource() |
509 | * Warning will be printed if there is collision. |
510 | */ |
511 | if (err && (err != -EEXIST)) |
512 | break; |
513 | err = 0; |
514 | } |
515 | |
516 | return err; |
517 | } |
518 | EXPORT_SYMBOL_GPL(__add_pages); |
519 | |
520 | #ifdef CONFIG_MEMORY_HOTREMOVE |
521 | /* find the smallest valid pfn in the range [start_pfn, end_pfn) */ |
522 | static int find_smallest_section_pfn(int nid, struct zone *zone, |
523 | unsigned long start_pfn, |
524 | unsigned long end_pfn) |
525 | { |
526 | struct mem_section *ms; |
527 | |
528 | for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SECTION) { |
529 | ms = __pfn_to_section(start_pfn); |
530 | |
531 | if (unlikely(!valid_section(ms))) |
532 | continue; |
533 | |
534 | if (unlikely(pfn_to_nid(start_pfn) != nid)) |
535 | continue; |
536 | |
537 | if (zone && zone != page_zone(pfn_to_page(start_pfn))) |
538 | continue; |
539 | |
540 | return start_pfn; |
541 | } |
542 | |
543 | return 0; |
544 | } |
545 | |
546 | /* find the biggest valid pfn in the range [start_pfn, end_pfn). */ |
547 | static int find_biggest_section_pfn(int nid, struct zone *zone, |
548 | unsigned long start_pfn, |
549 | unsigned long end_pfn) |
550 | { |
551 | struct mem_section *ms; |
552 | unsigned long pfn; |
553 | |
554 | /* pfn is the end pfn of a memory section. */ |
555 | pfn = end_pfn - 1; |
556 | for (; pfn >= start_pfn; pfn -= PAGES_PER_SECTION) { |
557 | ms = __pfn_to_section(pfn); |
558 | |
559 | if (unlikely(!valid_section(ms))) |
560 | continue; |
561 | |
562 | if (unlikely(pfn_to_nid(pfn) != nid)) |
563 | continue; |
564 | |
565 | if (zone && zone != page_zone(pfn_to_page(pfn))) |
566 | continue; |
567 | |
568 | return pfn; |
569 | } |
570 | |
571 | return 0; |
572 | } |
573 | |
574 | static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, |
575 | unsigned long end_pfn) |
576 | { |
577 | unsigned long zone_start_pfn = zone->zone_start_pfn; |
578 | unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */ |
579 | unsigned long zone_end_pfn = z; |
580 | unsigned long pfn; |
581 | struct mem_section *ms; |
582 | int nid = zone_to_nid(zone); |
583 | |
584 | zone_span_writelock(zone); |
585 | if (zone_start_pfn == start_pfn) { |
586 | /* |
587 | * If the section is smallest section in the zone, it need |
588 | * shrink zone->zone_start_pfn and zone->zone_spanned_pages. |
589 | * In this case, we find second smallest valid mem_section |
590 | * for shrinking zone. |
591 | */ |
592 | pfn = find_smallest_section_pfn(nid, zone, end_pfn, |
593 | zone_end_pfn); |
594 | if (pfn) { |
595 | zone->zone_start_pfn = pfn; |
596 | zone->spanned_pages = zone_end_pfn - pfn; |
597 | } |
598 | } else if (zone_end_pfn == end_pfn) { |
599 | /* |
600 | * If the section is biggest section in the zone, it need |
601 | * shrink zone->spanned_pages. |
602 | * In this case, we find second biggest valid mem_section for |
603 | * shrinking zone. |
604 | */ |
605 | pfn = find_biggest_section_pfn(nid, zone, zone_start_pfn, |
606 | start_pfn); |
607 | if (pfn) |
608 | zone->spanned_pages = pfn - zone_start_pfn + 1; |
609 | } |
610 | |
611 | /* |
612 | * The section is not biggest or smallest mem_section in the zone, it |
613 | * only creates a hole in the zone. So in this case, we need not |
614 | * change the zone. But perhaps, the zone has only hole data. Thus |
615 | * it check the zone has only hole or not. |
616 | */ |
617 | pfn = zone_start_pfn; |
618 | for (; pfn < zone_end_pfn; pfn += PAGES_PER_SECTION) { |
619 | ms = __pfn_to_section(pfn); |
620 | |
621 | if (unlikely(!valid_section(ms))) |
622 | continue; |
623 | |
624 | if (page_zone(pfn_to_page(pfn)) != zone) |
625 | continue; |
626 | |
627 | /* If the section is current section, it continues the loop */ |
628 | if (start_pfn == pfn) |
629 | continue; |
630 | |
631 | /* If we find valid section, we have nothing to do */ |
632 | zone_span_writeunlock(zone); |
633 | return; |
634 | } |
635 | |
636 | /* The zone has no valid section */ |
637 | zone->zone_start_pfn = 0; |
638 | zone->spanned_pages = 0; |
639 | zone_span_writeunlock(zone); |
640 | } |
641 | |
642 | static void shrink_pgdat_span(struct pglist_data *pgdat, |
643 | unsigned long start_pfn, unsigned long end_pfn) |
644 | { |
645 | unsigned long pgdat_start_pfn = pgdat->node_start_pfn; |
646 | unsigned long p = pgdat_end_pfn(pgdat); /* pgdat_end_pfn namespace clash */ |
647 | unsigned long pgdat_end_pfn = p; |
648 | unsigned long pfn; |
649 | struct mem_section *ms; |
650 | int nid = pgdat->node_id; |
651 | |
652 | if (pgdat_start_pfn == start_pfn) { |
653 | /* |
654 | * If the section is smallest section in the pgdat, it need |
655 | * shrink pgdat->node_start_pfn and pgdat->node_spanned_pages. |
656 | * In this case, we find second smallest valid mem_section |
657 | * for shrinking zone. |
658 | */ |
659 | pfn = find_smallest_section_pfn(nid, NULL, end_pfn, |
660 | pgdat_end_pfn); |
661 | if (pfn) { |
662 | pgdat->node_start_pfn = pfn; |
663 | pgdat->node_spanned_pages = pgdat_end_pfn - pfn; |
664 | } |
665 | } else if (pgdat_end_pfn == end_pfn) { |
666 | /* |
667 | * If the section is biggest section in the pgdat, it need |
668 | * shrink pgdat->node_spanned_pages. |
669 | * In this case, we find second biggest valid mem_section for |
670 | * shrinking zone. |
671 | */ |
672 | pfn = find_biggest_section_pfn(nid, NULL, pgdat_start_pfn, |
673 | start_pfn); |
674 | if (pfn) |
675 | pgdat->node_spanned_pages = pfn - pgdat_start_pfn + 1; |
676 | } |
677 | |
678 | /* |
679 | * If the section is not biggest or smallest mem_section in the pgdat, |
680 | * it only creates a hole in the pgdat. So in this case, we need not |
681 | * change the pgdat. |
682 | * But perhaps, the pgdat has only hole data. Thus it check the pgdat |
683 | * has only hole or not. |
684 | */ |
685 | pfn = pgdat_start_pfn; |
686 | for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SECTION) { |
687 | ms = __pfn_to_section(pfn); |
688 | |
689 | if (unlikely(!valid_section(ms))) |
690 | continue; |
691 | |
692 | if (pfn_to_nid(pfn) != nid) |
693 | continue; |
694 | |
695 | /* If the section is current section, it continues the loop */ |
696 | if (start_pfn == pfn) |
697 | continue; |
698 | |
699 | /* If we find valid section, we have nothing to do */ |
700 | return; |
701 | } |
702 | |
703 | /* The pgdat has no valid section */ |
704 | pgdat->node_start_pfn = 0; |
705 | pgdat->node_spanned_pages = 0; |
706 | } |
707 | |
708 | static void __remove_zone(struct zone *zone, unsigned long start_pfn) |
709 | { |
710 | struct pglist_data *pgdat = zone->zone_pgdat; |
711 | int nr_pages = PAGES_PER_SECTION; |
712 | int zone_type; |
713 | unsigned long flags; |
714 | |
715 | zone_type = zone - pgdat->node_zones; |
716 | |
717 | pgdat_resize_lock(zone->zone_pgdat, &flags); |
718 | shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); |
719 | shrink_pgdat_span(pgdat, start_pfn, start_pfn + nr_pages); |
720 | pgdat_resize_unlock(zone->zone_pgdat, &flags); |
721 | } |
722 | |
723 | static int __remove_section(struct zone *zone, struct mem_section *ms) |
724 | { |
725 | unsigned long start_pfn; |
726 | int scn_nr; |
727 | int ret = -EINVAL; |
728 | |
729 | if (!valid_section(ms)) |
730 | return ret; |
731 | |
732 | ret = unregister_memory_section(ms); |
733 | if (ret) |
734 | return ret; |
735 | |
736 | scn_nr = __section_nr(ms); |
737 | start_pfn = section_nr_to_pfn(scn_nr); |
738 | __remove_zone(zone, start_pfn); |
739 | |
740 | sparse_remove_one_section(zone, ms); |
741 | return 0; |
742 | } |
743 | |
744 | /** |
745 | * __remove_pages() - remove sections of pages from a zone |
746 | * @zone: zone from which pages need to be removed |
747 | * @phys_start_pfn: starting pageframe (must be aligned to start of a section) |
748 | * @nr_pages: number of pages to remove (must be multiple of section size) |
749 | * |
750 | * Generic helper function to remove section mappings and sysfs entries |
751 | * for the section of the memory we are removing. Caller needs to make |
752 | * sure that pages are marked reserved and zones are adjust properly by |
753 | * calling offline_pages(). |
754 | */ |
755 | int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, |
756 | unsigned long nr_pages) |
757 | { |
758 | unsigned long i; |
759 | int sections_to_remove; |
760 | resource_size_t start, size; |
761 | int ret = 0; |
762 | |
763 | /* |
764 | * We can only remove entire sections |
765 | */ |
766 | BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK); |
767 | BUG_ON(nr_pages % PAGES_PER_SECTION); |
768 | |
769 | start = phys_start_pfn << PAGE_SHIFT; |
770 | size = nr_pages * PAGE_SIZE; |
771 | ret = release_mem_region_adjustable(&iomem_resource, start, size); |
772 | if (ret) { |
773 | resource_size_t endres = start + size - 1; |
774 | |
775 | pr_warn("Unable to release resource <%pa-%pa> (%d)\n", |
776 | &start, &endres, ret); |
777 | } |
778 | |
779 | sections_to_remove = nr_pages / PAGES_PER_SECTION; |
780 | for (i = 0; i < sections_to_remove; i++) { |
781 | unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION; |
782 | ret = __remove_section(zone, __pfn_to_section(pfn)); |
783 | if (ret) |
784 | break; |
785 | } |
786 | return ret; |
787 | } |
788 | EXPORT_SYMBOL_GPL(__remove_pages); |
789 | #endif /* CONFIG_MEMORY_HOTREMOVE */ |
790 | |
791 | int set_online_page_callback(online_page_callback_t callback) |
792 | { |
793 | int rc = -EINVAL; |
794 | |
795 | get_online_mems(); |
796 | mutex_lock(&online_page_callback_lock); |
797 | |
798 | if (online_page_callback == generic_online_page) { |
799 | online_page_callback = callback; |
800 | rc = 0; |
801 | } |
802 | |
803 | mutex_unlock(&online_page_callback_lock); |
804 | put_online_mems(); |
805 | |
806 | return rc; |
807 | } |
808 | EXPORT_SYMBOL_GPL(set_online_page_callback); |
809 | |
810 | int restore_online_page_callback(online_page_callback_t callback) |
811 | { |
812 | int rc = -EINVAL; |
813 | |
814 | get_online_mems(); |
815 | mutex_lock(&online_page_callback_lock); |
816 | |
817 | if (online_page_callback == callback) { |
818 | online_page_callback = generic_online_page; |
819 | rc = 0; |
820 | } |
821 | |
822 | mutex_unlock(&online_page_callback_lock); |
823 | put_online_mems(); |
824 | |
825 | return rc; |
826 | } |
827 | EXPORT_SYMBOL_GPL(restore_online_page_callback); |
828 | |
829 | void __online_page_set_limits(struct page *page) |
830 | { |
831 | } |
832 | EXPORT_SYMBOL_GPL(__online_page_set_limits); |
833 | |
834 | void __online_page_increment_counters(struct page *page) |
835 | { |
836 | adjust_managed_page_count(page, 1); |
837 | } |
838 | EXPORT_SYMBOL_GPL(__online_page_increment_counters); |
839 | |
840 | void __online_page_free(struct page *page) |
841 | { |
842 | __free_reserved_page(page); |
843 | } |
844 | EXPORT_SYMBOL_GPL(__online_page_free); |
845 | |
846 | static void generic_online_page(struct page *page) |
847 | { |
848 | __online_page_set_limits(page); |
849 | __online_page_increment_counters(page); |
850 | __online_page_free(page); |
851 | } |
852 | |
853 | static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, |
854 | void *arg) |
855 | { |
856 | unsigned long i; |
857 | unsigned long onlined_pages = *(unsigned long *)arg; |
858 | struct page *page; |
859 | if (PageReserved(pfn_to_page(start_pfn))) |
860 | for (i = 0; i < nr_pages; i++) { |
861 | page = pfn_to_page(start_pfn + i); |
862 | (*online_page_callback)(page); |
863 | onlined_pages++; |
864 | } |
865 | *(unsigned long *)arg = onlined_pages; |
866 | return 0; |
867 | } |
868 | |
869 | #ifdef CONFIG_MOVABLE_NODE |
870 | /* |
871 | * When CONFIG_MOVABLE_NODE, we permit onlining of a node which doesn't have |
872 | * normal memory. |
873 | */ |
874 | static bool can_online_high_movable(struct zone *zone) |
875 | { |
876 | return true; |
877 | } |
878 | #else /* CONFIG_MOVABLE_NODE */ |
879 | /* ensure every online node has NORMAL memory */ |
880 | static bool can_online_high_movable(struct zone *zone) |
881 | { |
882 | return node_state(zone_to_nid(zone), N_NORMAL_MEMORY); |
883 | } |
884 | #endif /* CONFIG_MOVABLE_NODE */ |
885 | |
886 | /* check which state of node_states will be changed when online memory */ |
887 | static void node_states_check_changes_online(unsigned long nr_pages, |
888 | struct zone *zone, struct memory_notify *arg) |
889 | { |
890 | int nid = zone_to_nid(zone); |
891 | enum zone_type zone_last = ZONE_NORMAL; |
892 | |
893 | /* |
894 | * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY] |
895 | * contains nodes which have zones of 0...ZONE_NORMAL, |
896 | * set zone_last to ZONE_NORMAL. |
897 | * |
898 | * If we don't have HIGHMEM nor movable node, |
899 | * node_states[N_NORMAL_MEMORY] contains nodes which have zones of |
900 | * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE. |
901 | */ |
902 | if (N_MEMORY == N_NORMAL_MEMORY) |
903 | zone_last = ZONE_MOVABLE; |
904 | |
905 | /* |
906 | * if the memory to be online is in a zone of 0...zone_last, and |
907 | * the zones of 0...zone_last don't have memory before online, we will |
908 | * need to set the node to node_states[N_NORMAL_MEMORY] after |
909 | * the memory is online. |
910 | */ |
911 | if (zone_idx(zone) <= zone_last && !node_state(nid, N_NORMAL_MEMORY)) |
912 | arg->status_change_nid_normal = nid; |
913 | else |
914 | arg->status_change_nid_normal = -1; |
915 | |
916 | #ifdef CONFIG_HIGHMEM |
917 | /* |
918 | * If we have movable node, node_states[N_HIGH_MEMORY] |
919 | * contains nodes which have zones of 0...ZONE_HIGHMEM, |
920 | * set zone_last to ZONE_HIGHMEM. |
921 | * |
922 | * If we don't have movable node, node_states[N_NORMAL_MEMORY] |
923 | * contains nodes which have zones of 0...ZONE_MOVABLE, |
924 | * set zone_last to ZONE_MOVABLE. |
925 | */ |
926 | zone_last = ZONE_HIGHMEM; |
927 | if (N_MEMORY == N_HIGH_MEMORY) |
928 | zone_last = ZONE_MOVABLE; |
929 | |
930 | if (zone_idx(zone) <= zone_last && !node_state(nid, N_HIGH_MEMORY)) |
931 | arg->status_change_nid_high = nid; |
932 | else |
933 | arg->status_change_nid_high = -1; |
934 | #else |
935 | arg->status_change_nid_high = arg->status_change_nid_normal; |
936 | #endif |
937 | |
938 | /* |
939 | * if the node don't have memory befor online, we will need to |
940 | * set the node to node_states[N_MEMORY] after the memory |
941 | * is online. |
942 | */ |
943 | if (!node_state(nid, N_MEMORY)) |
944 | arg->status_change_nid = nid; |
945 | else |
946 | arg->status_change_nid = -1; |
947 | } |
948 | |
949 | static void node_states_set_node(int node, struct memory_notify *arg) |
950 | { |
951 | if (arg->status_change_nid_normal >= 0) |
952 | node_set_state(node, N_NORMAL_MEMORY); |
953 | |
954 | if (arg->status_change_nid_high >= 0) |
955 | node_set_state(node, N_HIGH_MEMORY); |
956 | |
957 | node_set_state(node, N_MEMORY); |
958 | } |
959 | |
960 | |
961 | int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type) |
962 | { |
963 | unsigned long flags; |
964 | unsigned long onlined_pages = 0; |
965 | struct zone *zone; |
966 | int need_zonelists_rebuild = 0; |
967 | int nid; |
968 | int ret; |
969 | struct memory_notify arg; |
970 | |
971 | mem_hotplug_begin(); |
972 | /* |
973 | * This doesn't need a lock to do pfn_to_page(). |
974 | * The section can't be removed here because of the |
975 | * memory_block->state_mutex. |
976 | */ |
977 | zone = page_zone(pfn_to_page(pfn)); |
978 | |
979 | ret = -EINVAL; |
980 | if ((zone_idx(zone) > ZONE_NORMAL || online_type == ONLINE_MOVABLE) && |
981 | !can_online_high_movable(zone)) |
982 | goto out; |
983 | |
984 | if (online_type == ONLINE_KERNEL && zone_idx(zone) == ZONE_MOVABLE) { |
985 | if (move_pfn_range_left(zone - 1, zone, pfn, pfn + nr_pages)) |
986 | goto out; |
987 | } |
988 | if (online_type == ONLINE_MOVABLE && zone_idx(zone) == ZONE_MOVABLE - 1) { |
989 | if (move_pfn_range_right(zone, zone + 1, pfn, pfn + nr_pages)) |
990 | goto out; |
991 | } |
992 | |
993 | /* Previous code may changed the zone of the pfn range */ |
994 | zone = page_zone(pfn_to_page(pfn)); |
995 | |
996 | arg.start_pfn = pfn; |
997 | arg.nr_pages = nr_pages; |
998 | node_states_check_changes_online(nr_pages, zone, &arg); |
999 | |
1000 | nid = pfn_to_nid(pfn); |
1001 | |
1002 | ret = memory_notify(MEM_GOING_ONLINE, &arg); |
1003 | ret = notifier_to_errno(ret); |
1004 | if (ret) { |
1005 | memory_notify(MEM_CANCEL_ONLINE, &arg); |
1006 | goto out; |
1007 | } |
1008 | /* |
1009 | * If this zone is not populated, then it is not in zonelist. |
1010 | * This means the page allocator ignores this zone. |
1011 | * So, zonelist must be updated after online. |
1012 | */ |
1013 | mutex_lock(&zonelists_mutex); |
1014 | if (!populated_zone(zone)) { |
1015 | need_zonelists_rebuild = 1; |
1016 | build_all_zonelists(NULL, zone); |
1017 | } |
1018 | |
1019 | ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages, |
1020 | online_pages_range); |
1021 | if (ret) { |
1022 | if (need_zonelists_rebuild) |
1023 | zone_pcp_reset(zone); |
1024 | mutex_unlock(&zonelists_mutex); |
1025 | printk(KERN_DEBUG "online_pages [mem %#010llx-%#010llx] failed\n", |
1026 | (unsigned long long) pfn << PAGE_SHIFT, |
1027 | (((unsigned long long) pfn + nr_pages) |
1028 | << PAGE_SHIFT) - 1); |
1029 | memory_notify(MEM_CANCEL_ONLINE, &arg); |
1030 | goto out; |
1031 | } |
1032 | |
1033 | zone->present_pages += onlined_pages; |
1034 | |
1035 | pgdat_resize_lock(zone->zone_pgdat, &flags); |
1036 | zone->zone_pgdat->node_present_pages += onlined_pages; |
1037 | pgdat_resize_unlock(zone->zone_pgdat, &flags); |
1038 | |
1039 | if (onlined_pages) { |
1040 | node_states_set_node(zone_to_nid(zone), &arg); |
1041 | if (need_zonelists_rebuild) |
1042 | build_all_zonelists(NULL, NULL); |
1043 | else |
1044 | zone_pcp_update(zone); |
1045 | } |
1046 | |
1047 | mutex_unlock(&zonelists_mutex); |
1048 | |
1049 | init_per_zone_wmark_min(); |
1050 | |
1051 | if (onlined_pages) |
1052 | kswapd_run(zone_to_nid(zone)); |
1053 | |
1054 | vm_total_pages = nr_free_pagecache_pages(); |
1055 | |
1056 | writeback_set_ratelimit(); |
1057 | |
1058 | if (onlined_pages) |
1059 | memory_notify(MEM_ONLINE, &arg); |
1060 | out: |
1061 | mem_hotplug_done(); |
1062 | return ret; |
1063 | } |
1064 | #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ |
1065 | |
1066 | /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ |
1067 | static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) |
1068 | { |
1069 | struct pglist_data *pgdat; |
1070 | unsigned long zones_size[MAX_NR_ZONES] = {0}; |
1071 | unsigned long zholes_size[MAX_NR_ZONES] = {0}; |
1072 | unsigned long start_pfn = PFN_DOWN(start); |
1073 | |
1074 | pgdat = NODE_DATA(nid); |
1075 | if (!pgdat) { |
1076 | pgdat = arch_alloc_nodedata(nid); |
1077 | if (!pgdat) |
1078 | return NULL; |
1079 | |
1080 | arch_refresh_nodedata(nid, pgdat); |
1081 | } |
1082 | |
1083 | /* we can use NODE_DATA(nid) from here */ |
1084 | |
1085 | /* init node's zones as empty zones, we don't have any present pages.*/ |
1086 | free_area_init_node(nid, zones_size, start_pfn, zholes_size); |
1087 | |
1088 | /* |
1089 | * The node we allocated has no zone fallback lists. For avoiding |
1090 | * to access not-initialized zonelist, build here. |
1091 | */ |
1092 | mutex_lock(&zonelists_mutex); |
1093 | build_all_zonelists(pgdat, NULL); |
1094 | mutex_unlock(&zonelists_mutex); |
1095 | |
1096 | return pgdat; |
1097 | } |
1098 | |
1099 | static void rollback_node_hotadd(int nid, pg_data_t *pgdat) |
1100 | { |
1101 | arch_refresh_nodedata(nid, NULL); |
1102 | arch_free_nodedata(pgdat); |
1103 | return; |
1104 | } |
1105 | |
1106 | |
1107 | /** |
1108 | * try_online_node - online a node if offlined |
1109 | * |
1110 | * called by cpu_up() to online a node without onlined memory. |
1111 | */ |
1112 | int try_online_node(int nid) |
1113 | { |
1114 | pg_data_t *pgdat; |
1115 | int ret; |
1116 | |
1117 | if (node_online(nid)) |
1118 | return 0; |
1119 | |
1120 | mem_hotplug_begin(); |
1121 | pgdat = hotadd_new_pgdat(nid, 0); |
1122 | if (!pgdat) { |
1123 | pr_err("Cannot online node %d due to NULL pgdat\n", nid); |
1124 | ret = -ENOMEM; |
1125 | goto out; |
1126 | } |
1127 | node_set_online(nid); |
1128 | ret = register_one_node(nid); |
1129 | BUG_ON(ret); |
1130 | |
1131 | if (pgdat->node_zonelists->_zonerefs->zone == NULL) { |
1132 | mutex_lock(&zonelists_mutex); |
1133 | build_all_zonelists(NULL, NULL); |
1134 | mutex_unlock(&zonelists_mutex); |
1135 | } |
1136 | |
1137 | out: |
1138 | mem_hotplug_done(); |
1139 | return ret; |
1140 | } |
1141 | |
1142 | static int check_hotplug_memory_range(u64 start, u64 size) |
1143 | { |
1144 | u64 start_pfn = PFN_DOWN(start); |
1145 | u64 nr_pages = size >> PAGE_SHIFT; |
1146 | |
1147 | /* Memory range must be aligned with section */ |
1148 | if ((start_pfn & ~PAGE_SECTION_MASK) || |
1149 | (nr_pages % PAGES_PER_SECTION) || (!nr_pages)) { |
1150 | pr_err("Section-unaligned hotplug range: start 0x%llx, size 0x%llx\n", |
1151 | (unsigned long long)start, |
1152 | (unsigned long long)size); |
1153 | return -EINVAL; |
1154 | } |
1155 | |
1156 | return 0; |
1157 | } |
1158 | |
1159 | /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ |
1160 | int __ref add_memory(int nid, u64 start, u64 size) |
1161 | { |
1162 | pg_data_t *pgdat = NULL; |
1163 | bool new_pgdat; |
1164 | bool new_node; |
1165 | struct resource *res; |
1166 | int ret; |
1167 | |
1168 | ret = check_hotplug_memory_range(start, size); |
1169 | if (ret) |
1170 | return ret; |
1171 | |
1172 | res = register_memory_resource(start, size); |
1173 | ret = -EEXIST; |
1174 | if (!res) |
1175 | return ret; |
1176 | |
1177 | { /* Stupid hack to suppress address-never-null warning */ |
1178 | void *p = NODE_DATA(nid); |
1179 | new_pgdat = !p; |
1180 | } |
1181 | |
1182 | mem_hotplug_begin(); |
1183 | |
1184 | new_node = !node_online(nid); |
1185 | if (new_node) { |
1186 | pgdat = hotadd_new_pgdat(nid, start); |
1187 | ret = -ENOMEM; |
1188 | if (!pgdat) |
1189 | goto error; |
1190 | } |
1191 | |
1192 | /* call arch's memory hotadd */ |
1193 | ret = arch_add_memory(nid, start, size); |
1194 | |
1195 | if (ret < 0) |
1196 | goto error; |
1197 | |
1198 | /* we online node here. we can't roll back from here. */ |
1199 | node_set_online(nid); |
1200 | |
1201 | if (new_node) { |
1202 | ret = register_one_node(nid); |
1203 | /* |
1204 | * If sysfs file of new node can't create, cpu on the node |
1205 | * can't be hot-added. There is no rollback way now. |
1206 | * So, check by BUG_ON() to catch it reluctantly.. |
1207 | */ |
1208 | BUG_ON(ret); |
1209 | } |
1210 | |
1211 | /* create new memmap entry */ |
1212 | firmware_map_add_hotplug(start, start + size, "System RAM"); |
1213 | |
1214 | goto out; |
1215 | |
1216 | error: |
1217 | /* rollback pgdat allocation and others */ |
1218 | if (new_pgdat) |
1219 | rollback_node_hotadd(nid, pgdat); |
1220 | release_memory_resource(res); |
1221 | |
1222 | out: |
1223 | mem_hotplug_done(); |
1224 | return ret; |
1225 | } |
1226 | EXPORT_SYMBOL_GPL(add_memory); |
1227 | |
1228 | #ifdef CONFIG_MEMORY_HOTREMOVE |
1229 | /* |
1230 | * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy |
1231 | * set and the size of the free page is given by page_order(). Using this, |
1232 | * the function determines if the pageblock contains only free pages. |
1233 | * Due to buddy contraints, a free page at least the size of a pageblock will |
1234 | * be located at the start of the pageblock |
1235 | */ |
1236 | static inline int pageblock_free(struct page *page) |
1237 | { |
1238 | return PageBuddy(page) && page_order(page) >= pageblock_order; |
1239 | } |
1240 | |
1241 | /* Return the start of the next active pageblock after a given page */ |
1242 | static struct page *next_active_pageblock(struct page *page) |
1243 | { |
1244 | /* Ensure the starting page is pageblock-aligned */ |
1245 | BUG_ON(page_to_pfn(page) & (pageblock_nr_pages - 1)); |
1246 | |
1247 | /* If the entire pageblock is free, move to the end of free page */ |
1248 | if (pageblock_free(page)) { |
1249 | int order; |
1250 | /* be careful. we don't have locks, page_order can be changed.*/ |
1251 | order = page_order(page); |
1252 | if ((order < MAX_ORDER) && (order >= pageblock_order)) |
1253 | return page + (1 << order); |
1254 | } |
1255 | |
1256 | return page + pageblock_nr_pages; |
1257 | } |
1258 | |
1259 | /* Checks if this range of memory is likely to be hot-removable. */ |
1260 | int is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages) |
1261 | { |
1262 | struct page *page = pfn_to_page(start_pfn); |
1263 | struct page *end_page = page + nr_pages; |
1264 | |
1265 | /* Check the starting page of each pageblock within the range */ |
1266 | for (; page < end_page; page = next_active_pageblock(page)) { |
1267 | if (!is_pageblock_removable_nolock(page)) |
1268 | return 0; |
1269 | cond_resched(); |
1270 | } |
1271 | |
1272 | /* All pageblocks in the memory block are likely to be hot-removable */ |
1273 | return 1; |
1274 | } |
1275 | |
1276 | /* |
1277 | * Confirm all pages in a range [start, end) is belongs to the same zone. |
1278 | */ |
1279 | static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn) |
1280 | { |
1281 | unsigned long pfn; |
1282 | struct zone *zone = NULL; |
1283 | struct page *page; |
1284 | int i; |
1285 | for (pfn = start_pfn; |
1286 | pfn < end_pfn; |
1287 | pfn += MAX_ORDER_NR_PAGES) { |
1288 | i = 0; |
1289 | /* This is just a CONFIG_HOLES_IN_ZONE check.*/ |
1290 | while ((i < MAX_ORDER_NR_PAGES) && !pfn_valid_within(pfn + i)) |
1291 | i++; |
1292 | if (i == MAX_ORDER_NR_PAGES) |
1293 | continue; |
1294 | page = pfn_to_page(pfn + i); |
1295 | if (zone && page_zone(page) != zone) |
1296 | return 0; |
1297 | zone = page_zone(page); |
1298 | } |
1299 | return 1; |
1300 | } |
1301 | |
1302 | /* |
1303 | * Scan pfn range [start,end) to find movable/migratable pages (LRU pages |
1304 | * and hugepages). We scan pfn because it's much easier than scanning over |
1305 | * linked list. This function returns the pfn of the first found movable |
1306 | * page if it's found, otherwise 0. |
1307 | */ |
1308 | static unsigned long scan_movable_pages(unsigned long start, unsigned long end) |
1309 | { |
1310 | unsigned long pfn; |
1311 | struct page *page; |
1312 | for (pfn = start; pfn < end; pfn++) { |
1313 | if (pfn_valid(pfn)) { |
1314 | page = pfn_to_page(pfn); |
1315 | if (PageLRU(page)) |
1316 | return pfn; |
1317 | if (PageHuge(page)) { |
1318 | if (is_hugepage_active(page)) |
1319 | return pfn; |
1320 | else |
1321 | pfn = round_up(pfn + 1, |
1322 | 1 << compound_order(page)) - 1; |
1323 | } |
1324 | } |
1325 | } |
1326 | return 0; |
1327 | } |
1328 | |
1329 | #define NR_OFFLINE_AT_ONCE_PAGES (256) |
1330 | static int |
1331 | do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) |
1332 | { |
1333 | unsigned long pfn; |
1334 | struct page *page; |
1335 | int move_pages = NR_OFFLINE_AT_ONCE_PAGES; |
1336 | int not_managed = 0; |
1337 | int ret = 0; |
1338 | LIST_HEAD(source); |
1339 | |
1340 | for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) { |
1341 | if (!pfn_valid(pfn)) |
1342 | continue; |
1343 | page = pfn_to_page(pfn); |
1344 | |
1345 | if (PageHuge(page)) { |
1346 | struct page *head = compound_head(page); |
1347 | pfn = page_to_pfn(head) + (1<<compound_order(head)) - 1; |
1348 | if (compound_order(head) > PFN_SECTION_SHIFT) { |
1349 | ret = -EBUSY; |
1350 | break; |
1351 | } |
1352 | if (isolate_huge_page(page, &source)) |
1353 | move_pages -= 1 << compound_order(head); |
1354 | continue; |
1355 | } |
1356 | |
1357 | if (!get_page_unless_zero(page)) |
1358 | continue; |
1359 | /* |
1360 | * We can skip free pages. And we can only deal with pages on |
1361 | * LRU. |
1362 | */ |
1363 | ret = isolate_lru_page(page); |
1364 | if (!ret) { /* Success */ |
1365 | put_page(page); |
1366 | list_add_tail(&page->lru, &source); |
1367 | move_pages--; |
1368 | inc_zone_page_state(page, NR_ISOLATED_ANON + |
1369 | page_is_file_cache(page)); |
1370 | |
1371 | } else { |
1372 | #ifdef CONFIG_DEBUG_VM |
1373 | printk(KERN_ALERT "removing pfn %lx from LRU failed\n", |
1374 | pfn); |
1375 | dump_page(page, "failed to remove from LRU"); |
1376 | #endif |
1377 | put_page(page); |
1378 | /* Because we don't have big zone->lock. we should |
1379 | check this again here. */ |
1380 | if (page_count(page)) { |
1381 | not_managed++; |
1382 | ret = -EBUSY; |
1383 | break; |
1384 | } |
1385 | } |
1386 | } |
1387 | if (!list_empty(&source)) { |
1388 | if (not_managed) { |
1389 | putback_movable_pages(&source); |
1390 | goto out; |
1391 | } |
1392 | |
1393 | /* |
1394 | * alloc_migrate_target should be improooooved!! |
1395 | * migrate_pages returns # of failed pages. |
1396 | */ |
1397 | ret = migrate_pages(&source, alloc_migrate_target, NULL, 0, |
1398 | MIGRATE_SYNC, MR_MEMORY_HOTPLUG); |
1399 | if (ret) |
1400 | putback_movable_pages(&source); |
1401 | } |
1402 | out: |
1403 | return ret; |
1404 | } |
1405 | |
1406 | /* |
1407 | * remove from free_area[] and mark all as Reserved. |
1408 | */ |
1409 | static int |
1410 | offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages, |
1411 | void *data) |
1412 | { |
1413 | __offline_isolated_pages(start, start + nr_pages); |
1414 | return 0; |
1415 | } |
1416 | |
1417 | static void |
1418 | offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) |
1419 | { |
1420 | walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL, |
1421 | offline_isolated_pages_cb); |
1422 | } |
1423 | |
1424 | /* |
1425 | * Check all pages in range, recoreded as memory resource, are isolated. |
1426 | */ |
1427 | static int |
1428 | check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages, |
1429 | void *data) |
1430 | { |
1431 | int ret; |
1432 | long offlined = *(long *)data; |
1433 | ret = test_pages_isolated(start_pfn, start_pfn + nr_pages, true); |
1434 | offlined = nr_pages; |
1435 | if (!ret) |
1436 | *(long *)data += offlined; |
1437 | return ret; |
1438 | } |
1439 | |
1440 | static long |
1441 | check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn) |
1442 | { |
1443 | long offlined = 0; |
1444 | int ret; |
1445 | |
1446 | ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined, |
1447 | check_pages_isolated_cb); |
1448 | if (ret < 0) |
1449 | offlined = (long)ret; |
1450 | return offlined; |
1451 | } |
1452 | |
1453 | #ifdef CONFIG_MOVABLE_NODE |
1454 | /* |
1455 | * When CONFIG_MOVABLE_NODE, we permit offlining of a node which doesn't have |
1456 | * normal memory. |
1457 | */ |
1458 | static bool can_offline_normal(struct zone *zone, unsigned long nr_pages) |
1459 | { |
1460 | return true; |
1461 | } |
1462 | #else /* CONFIG_MOVABLE_NODE */ |
1463 | /* ensure the node has NORMAL memory if it is still online */ |
1464 | static bool can_offline_normal(struct zone *zone, unsigned long nr_pages) |
1465 | { |
1466 | struct pglist_data *pgdat = zone->zone_pgdat; |
1467 | unsigned long present_pages = 0; |
1468 | enum zone_type zt; |
1469 | |
1470 | for (zt = 0; zt <= ZONE_NORMAL; zt++) |
1471 | present_pages += pgdat->node_zones[zt].present_pages; |
1472 | |
1473 | if (present_pages > nr_pages) |
1474 | return true; |
1475 | |
1476 | present_pages = 0; |
1477 | for (; zt <= ZONE_MOVABLE; zt++) |
1478 | present_pages += pgdat->node_zones[zt].present_pages; |
1479 | |
1480 | /* |
1481 | * we can't offline the last normal memory until all |
1482 | * higher memory is offlined. |
1483 | */ |
1484 | return present_pages == 0; |
1485 | } |
1486 | #endif /* CONFIG_MOVABLE_NODE */ |
1487 | |
1488 | static int __init cmdline_parse_movable_node(char *p) |
1489 | { |
1490 | #ifdef CONFIG_MOVABLE_NODE |
1491 | /* |
1492 | * Memory used by the kernel cannot be hot-removed because Linux |
1493 | * cannot migrate the kernel pages. When memory hotplug is |
1494 | * enabled, we should prevent memblock from allocating memory |
1495 | * for the kernel. |
1496 | * |
1497 | * ACPI SRAT records all hotpluggable memory ranges. But before |
1498 | * SRAT is parsed, we don't know about it. |
1499 | * |
1500 | * The kernel image is loaded into memory at very early time. We |
1501 | * cannot prevent this anyway. So on NUMA system, we set any |
1502 | * node the kernel resides in as un-hotpluggable. |
1503 | * |
1504 | * Since on modern servers, one node could have double-digit |
1505 | * gigabytes memory, we can assume the memory around the kernel |
1506 | * image is also un-hotpluggable. So before SRAT is parsed, just |
1507 | * allocate memory near the kernel image to try the best to keep |
1508 | * the kernel away from hotpluggable memory. |
1509 | */ |
1510 | memblock_set_bottom_up(true); |
1511 | movable_node_enabled = true; |
1512 | #else |
1513 | pr_warn("movable_node option not supported\n"); |
1514 | #endif |
1515 | return 0; |
1516 | } |
1517 | early_param("movable_node", cmdline_parse_movable_node); |
1518 | |
1519 | /* check which state of node_states will be changed when offline memory */ |
1520 | static void node_states_check_changes_offline(unsigned long nr_pages, |
1521 | struct zone *zone, struct memory_notify *arg) |
1522 | { |
1523 | struct pglist_data *pgdat = zone->zone_pgdat; |
1524 | unsigned long present_pages = 0; |
1525 | enum zone_type zt, zone_last = ZONE_NORMAL; |
1526 | |
1527 | /* |
1528 | * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY] |
1529 | * contains nodes which have zones of 0...ZONE_NORMAL, |
1530 | * set zone_last to ZONE_NORMAL. |
1531 | * |
1532 | * If we don't have HIGHMEM nor movable node, |
1533 | * node_states[N_NORMAL_MEMORY] contains nodes which have zones of |
1534 | * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE. |
1535 | */ |
1536 | if (N_MEMORY == N_NORMAL_MEMORY) |
1537 | zone_last = ZONE_MOVABLE; |
1538 | |
1539 | /* |
1540 | * check whether node_states[N_NORMAL_MEMORY] will be changed. |
1541 | * If the memory to be offline is in a zone of 0...zone_last, |
1542 | * and it is the last present memory, 0...zone_last will |
1543 | * become empty after offline , thus we can determind we will |
1544 | * need to clear the node from node_states[N_NORMAL_MEMORY]. |
1545 | */ |
1546 | for (zt = 0; zt <= zone_last; zt++) |
1547 | present_pages += pgdat->node_zones[zt].present_pages; |
1548 | if (zone_idx(zone) <= zone_last && nr_pages >= present_pages) |
1549 | arg->status_change_nid_normal = zone_to_nid(zone); |
1550 | else |
1551 | arg->status_change_nid_normal = -1; |
1552 | |
1553 | #ifdef CONFIG_HIGHMEM |
1554 | /* |
1555 | * If we have movable node, node_states[N_HIGH_MEMORY] |
1556 | * contains nodes which have zones of 0...ZONE_HIGHMEM, |
1557 | * set zone_last to ZONE_HIGHMEM. |
1558 | * |
1559 | * If we don't have movable node, node_states[N_NORMAL_MEMORY] |
1560 | * contains nodes which have zones of 0...ZONE_MOVABLE, |
1561 | * set zone_last to ZONE_MOVABLE. |
1562 | */ |
1563 | zone_last = ZONE_HIGHMEM; |
1564 | if (N_MEMORY == N_HIGH_MEMORY) |
1565 | zone_last = ZONE_MOVABLE; |
1566 | |
1567 | for (; zt <= zone_last; zt++) |
1568 | present_pages += pgdat->node_zones[zt].present_pages; |
1569 | if (zone_idx(zone) <= zone_last && nr_pages >= present_pages) |
1570 | arg->status_change_nid_high = zone_to_nid(zone); |
1571 | else |
1572 | arg->status_change_nid_high = -1; |
1573 | #else |
1574 | arg->status_change_nid_high = arg->status_change_nid_normal; |
1575 | #endif |
1576 | |
1577 | /* |
1578 | * node_states[N_HIGH_MEMORY] contains nodes which have 0...ZONE_MOVABLE |
1579 | */ |
1580 | zone_last = ZONE_MOVABLE; |
1581 | |
1582 | /* |
1583 | * check whether node_states[N_HIGH_MEMORY] will be changed |
1584 | * If we try to offline the last present @nr_pages from the node, |
1585 | * we can determind we will need to clear the node from |
1586 | * node_states[N_HIGH_MEMORY]. |
1587 | */ |
1588 | for (; zt <= zone_last; zt++) |
1589 | present_pages += pgdat->node_zones[zt].present_pages; |
1590 | if (nr_pages >= present_pages) |
1591 | arg->status_change_nid = zone_to_nid(zone); |
1592 | else |
1593 | arg->status_change_nid = -1; |
1594 | } |
1595 | |
1596 | static void node_states_clear_node(int node, struct memory_notify *arg) |
1597 | { |
1598 | if (arg->status_change_nid_normal >= 0) |
1599 | node_clear_state(node, N_NORMAL_MEMORY); |
1600 | |
1601 | if ((N_MEMORY != N_NORMAL_MEMORY) && |
1602 | (arg->status_change_nid_high >= 0)) |
1603 | node_clear_state(node, N_HIGH_MEMORY); |
1604 | |
1605 | if ((N_MEMORY != N_HIGH_MEMORY) && |
1606 | (arg->status_change_nid >= 0)) |
1607 | node_clear_state(node, N_MEMORY); |
1608 | } |
1609 | |
1610 | static int __ref __offline_pages(unsigned long start_pfn, |
1611 | unsigned long end_pfn, unsigned long timeout) |
1612 | { |
1613 | unsigned long pfn, nr_pages, expire; |
1614 | long offlined_pages; |
1615 | int ret, drain, retry_max, node; |
1616 | unsigned long flags; |
1617 | struct zone *zone; |
1618 | struct memory_notify arg; |
1619 | |
1620 | /* at least, alignment against pageblock is necessary */ |
1621 | if (!IS_ALIGNED(start_pfn, pageblock_nr_pages)) |
1622 | return -EINVAL; |
1623 | if (!IS_ALIGNED(end_pfn, pageblock_nr_pages)) |
1624 | return -EINVAL; |
1625 | /* This makes hotplug much easier...and readable. |
1626 | we assume this for now. .*/ |
1627 | if (!test_pages_in_a_zone(start_pfn, end_pfn)) |
1628 | return -EINVAL; |
1629 | |
1630 | mem_hotplug_begin(); |
1631 | |
1632 | zone = page_zone(pfn_to_page(start_pfn)); |
1633 | node = zone_to_nid(zone); |
1634 | nr_pages = end_pfn - start_pfn; |
1635 | |
1636 | ret = -EINVAL; |
1637 | if (zone_idx(zone) <= ZONE_NORMAL && !can_offline_normal(zone, nr_pages)) |
1638 | goto out; |
1639 | |
1640 | /* set above range as isolated */ |
1641 | ret = start_isolate_page_range(start_pfn, end_pfn, |
1642 | MIGRATE_MOVABLE, true); |
1643 | if (ret) |
1644 | goto out; |
1645 | |
1646 | arg.start_pfn = start_pfn; |
1647 | arg.nr_pages = nr_pages; |
1648 | node_states_check_changes_offline(nr_pages, zone, &arg); |
1649 | |
1650 | ret = memory_notify(MEM_GOING_OFFLINE, &arg); |
1651 | ret = notifier_to_errno(ret); |
1652 | if (ret) |
1653 | goto failed_removal; |
1654 | |
1655 | pfn = start_pfn; |
1656 | expire = jiffies + timeout; |
1657 | drain = 0; |
1658 | retry_max = 5; |
1659 | repeat: |
1660 | /* start memory hot removal */ |
1661 | ret = -EAGAIN; |
1662 | if (time_after(jiffies, expire)) |
1663 | goto failed_removal; |
1664 | ret = -EINTR; |
1665 | if (signal_pending(current)) |
1666 | goto failed_removal; |
1667 | ret = 0; |
1668 | if (drain) { |
1669 | lru_add_drain_all(); |
1670 | cond_resched(); |
1671 | drain_all_pages(); |
1672 | } |
1673 | |
1674 | pfn = scan_movable_pages(start_pfn, end_pfn); |
1675 | if (pfn) { /* We have movable pages */ |
1676 | ret = do_migrate_range(pfn, end_pfn); |
1677 | if (!ret) { |
1678 | drain = 1; |
1679 | goto repeat; |
1680 | } else { |
1681 | if (ret < 0) |
1682 | if (--retry_max == 0) |
1683 | goto failed_removal; |
1684 | yield(); |
1685 | drain = 1; |
1686 | goto repeat; |
1687 | } |
1688 | } |
1689 | /* drain all zone's lru pagevec, this is asynchronous... */ |
1690 | lru_add_drain_all(); |
1691 | yield(); |
1692 | /* drain pcp pages, this is synchronous. */ |
1693 | drain_all_pages(); |
1694 | /* |
1695 | * dissolve free hugepages in the memory block before doing offlining |
1696 | * actually in order to make hugetlbfs's object counting consistent. |
1697 | */ |
1698 | dissolve_free_huge_pages(start_pfn, end_pfn); |
1699 | /* check again */ |
1700 | offlined_pages = check_pages_isolated(start_pfn, end_pfn); |
1701 | if (offlined_pages < 0) { |
1702 | ret = -EBUSY; |
1703 | goto failed_removal; |
1704 | } |
1705 | printk(KERN_INFO "Offlined Pages %ld\n", offlined_pages); |
1706 | /* Ok, all of our target is isolated. |
1707 | We cannot do rollback at this point. */ |
1708 | offline_isolated_pages(start_pfn, end_pfn); |
1709 | /* reset pagetype flags and makes migrate type to be MOVABLE */ |
1710 | undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); |
1711 | /* removal success */ |
1712 | adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages); |
1713 | zone->present_pages -= offlined_pages; |
1714 | |
1715 | pgdat_resize_lock(zone->zone_pgdat, &flags); |
1716 | zone->zone_pgdat->node_present_pages -= offlined_pages; |
1717 | pgdat_resize_unlock(zone->zone_pgdat, &flags); |
1718 | |
1719 | init_per_zone_wmark_min(); |
1720 | |
1721 | if (!populated_zone(zone)) { |
1722 | zone_pcp_reset(zone); |
1723 | mutex_lock(&zonelists_mutex); |
1724 | build_all_zonelists(NULL, NULL); |
1725 | mutex_unlock(&zonelists_mutex); |
1726 | } else |
1727 | zone_pcp_update(zone); |
1728 | |
1729 | node_states_clear_node(node, &arg); |
1730 | if (arg.status_change_nid >= 0) |
1731 | kswapd_stop(node); |
1732 | |
1733 | vm_total_pages = nr_free_pagecache_pages(); |
1734 | writeback_set_ratelimit(); |
1735 | |
1736 | memory_notify(MEM_OFFLINE, &arg); |
1737 | mem_hotplug_done(); |
1738 | return 0; |
1739 | |
1740 | failed_removal: |
1741 | printk(KERN_INFO "memory offlining [mem %#010llx-%#010llx] failed\n", |
1742 | (unsigned long long) start_pfn << PAGE_SHIFT, |
1743 | ((unsigned long long) end_pfn << PAGE_SHIFT) - 1); |
1744 | memory_notify(MEM_CANCEL_OFFLINE, &arg); |
1745 | /* pushback to free area */ |
1746 | undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); |
1747 | |
1748 | out: |
1749 | mem_hotplug_done(); |
1750 | return ret; |
1751 | } |
1752 | |
1753 | int offline_pages(unsigned long start_pfn, unsigned long nr_pages) |
1754 | { |
1755 | return __offline_pages(start_pfn, start_pfn + nr_pages, 120 * HZ); |
1756 | } |
1757 | #endif /* CONFIG_MEMORY_HOTREMOVE */ |
1758 | |
1759 | /** |
1760 | * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn) |
1761 | * @start_pfn: start pfn of the memory range |
1762 | * @end_pfn: end pfn of the memory range |
1763 | * @arg: argument passed to func |
1764 | * @func: callback for each memory section walked |
1765 | * |
1766 | * This function walks through all present mem sections in range |
1767 | * [start_pfn, end_pfn) and call func on each mem section. |
1768 | * |
1769 | * Returns the return value of func. |
1770 | */ |
1771 | int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, |
1772 | void *arg, int (*func)(struct memory_block *, void *)) |
1773 | { |
1774 | struct memory_block *mem = NULL; |
1775 | struct mem_section *section; |
1776 | unsigned long pfn, section_nr; |
1777 | int ret; |
1778 | |
1779 | for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { |
1780 | section_nr = pfn_to_section_nr(pfn); |
1781 | if (!present_section_nr(section_nr)) |
1782 | continue; |
1783 | |
1784 | section = __nr_to_section(section_nr); |
1785 | /* same memblock? */ |
1786 | if (mem) |
1787 | if ((section_nr >= mem->start_section_nr) && |
1788 | (section_nr <= mem->end_section_nr)) |
1789 | continue; |
1790 | |
1791 | mem = find_memory_block_hinted(section, mem); |
1792 | if (!mem) |
1793 | continue; |
1794 | |
1795 | ret = func(mem, arg); |
1796 | if (ret) { |
1797 | kobject_put(&mem->dev.kobj); |
1798 | return ret; |
1799 | } |
1800 | } |
1801 | |
1802 | if (mem) |
1803 | kobject_put(&mem->dev.kobj); |
1804 | |
1805 | return 0; |
1806 | } |
1807 | |
1808 | #ifdef CONFIG_MEMORY_HOTREMOVE |
1809 | static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) |
1810 | { |
1811 | int ret = !is_memblock_offlined(mem); |
1812 | |
1813 | if (unlikely(ret)) { |
1814 | phys_addr_t beginpa, endpa; |
1815 | |
1816 | beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)); |
1817 | endpa = PFN_PHYS(section_nr_to_pfn(mem->end_section_nr + 1))-1; |
1818 | pr_warn("removing memory fails, because memory " |
1819 | "[%pa-%pa] is onlined\n", |
1820 | &beginpa, &endpa); |
1821 | } |
1822 | |
1823 | return ret; |
1824 | } |
1825 | |
1826 | static int check_cpu_on_node(pg_data_t *pgdat) |
1827 | { |
1828 | int cpu; |
1829 | |
1830 | for_each_present_cpu(cpu) { |
1831 | if (cpu_to_node(cpu) == pgdat->node_id) |
1832 | /* |
1833 | * the cpu on this node isn't removed, and we can't |
1834 | * offline this node. |
1835 | */ |
1836 | return -EBUSY; |
1837 | } |
1838 | |
1839 | return 0; |
1840 | } |
1841 | |
1842 | static void unmap_cpu_on_node(pg_data_t *pgdat) |
1843 | { |
1844 | #ifdef CONFIG_ACPI_NUMA |
1845 | int cpu; |
1846 | |
1847 | for_each_possible_cpu(cpu) |
1848 | if (cpu_to_node(cpu) == pgdat->node_id) |
1849 | numa_clear_node(cpu); |
1850 | #endif |
1851 | } |
1852 | |
1853 | static int check_and_unmap_cpu_on_node(pg_data_t *pgdat) |
1854 | { |
1855 | int ret; |
1856 | |
1857 | ret = check_cpu_on_node(pgdat); |
1858 | if (ret) |
1859 | return ret; |
1860 | |
1861 | /* |
1862 | * the node will be offlined when we come here, so we can clear |
1863 | * the cpu_to_node() now. |
1864 | */ |
1865 | |
1866 | unmap_cpu_on_node(pgdat); |
1867 | return 0; |
1868 | } |
1869 | |
1870 | /** |
1871 | * try_offline_node |
1872 | * |
1873 | * Offline a node if all memory sections and cpus of the node are removed. |
1874 | * |
1875 | * NOTE: The caller must call lock_device_hotplug() to serialize hotplug |
1876 | * and online/offline operations before this call. |
1877 | */ |
1878 | void try_offline_node(int nid) |
1879 | { |
1880 | pg_data_t *pgdat = NODE_DATA(nid); |
1881 | unsigned long start_pfn = pgdat->node_start_pfn; |
1882 | unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages; |
1883 | unsigned long pfn; |
1884 | struct page *pgdat_page = virt_to_page(pgdat); |
1885 | int i; |
1886 | |
1887 | for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { |
1888 | unsigned long section_nr = pfn_to_section_nr(pfn); |
1889 | |
1890 | if (!present_section_nr(section_nr)) |
1891 | continue; |
1892 | |
1893 | if (pfn_to_nid(pfn) != nid) |
1894 | continue; |
1895 | |
1896 | /* |
1897 | * some memory sections of this node are not removed, and we |
1898 | * can't offline node now. |
1899 | */ |
1900 | return; |
1901 | } |
1902 | |
1903 | if (check_and_unmap_cpu_on_node(pgdat)) |
1904 | return; |
1905 | |
1906 | /* |
1907 | * all memory/cpu of this node are removed, we can offline this |
1908 | * node now. |
1909 | */ |
1910 | node_set_offline(nid); |
1911 | unregister_one_node(nid); |
1912 | |
1913 | if (!PageSlab(pgdat_page) && !PageCompound(pgdat_page)) |
1914 | /* node data is allocated from boot memory */ |
1915 | return; |
1916 | |
1917 | /* free waittable in each zone */ |
1918 | for (i = 0; i < MAX_NR_ZONES; i++) { |
1919 | struct zone *zone = pgdat->node_zones + i; |
1920 | |
1921 | /* |
1922 | * wait_table may be allocated from boot memory, |
1923 | * here only free if it's allocated by vmalloc. |
1924 | */ |
1925 | if (is_vmalloc_addr(zone->wait_table)) |
1926 | vfree(zone->wait_table); |
1927 | } |
1928 | |
1929 | /* |
1930 | * Since there is no way to guarentee the address of pgdat/zone is not |
1931 | * on stack of any kernel threads or used by other kernel objects |
1932 | * without reference counting or other symchronizing method, do not |
1933 | * reset node_data and free pgdat here. Just reset it to 0 and reuse |
1934 | * the memory when the node is online again. |
1935 | */ |
1936 | memset(pgdat, 0, sizeof(*pgdat)); |
1937 | } |
1938 | EXPORT_SYMBOL(try_offline_node); |
1939 | |
1940 | /** |
1941 | * remove_memory |
1942 | * |
1943 | * NOTE: The caller must call lock_device_hotplug() to serialize hotplug |
1944 | * and online/offline operations before this call, as required by |
1945 | * try_offline_node(). |
1946 | */ |
1947 | void __ref remove_memory(int nid, u64 start, u64 size) |
1948 | { |
1949 | int ret; |
1950 | |
1951 | BUG_ON(check_hotplug_memory_range(start, size)); |
1952 | |
1953 | mem_hotplug_begin(); |
1954 | |
1955 | /* |
1956 | * All memory blocks must be offlined before removing memory. Check |
1957 | * whether all memory blocks in question are offline and trigger a BUG() |
1958 | * if this is not the case. |
1959 | */ |
1960 | ret = walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), NULL, |
1961 | check_memblock_offlined_cb); |
1962 | if (ret) |
1963 | BUG(); |
1964 | |
1965 | /* remove memmap entry */ |
1966 | firmware_map_remove(start, start + size, "System RAM"); |
1967 | |
1968 | arch_remove_memory(start, size); |
1969 | |
1970 | try_offline_node(nid); |
1971 | |
1972 | mem_hotplug_done(); |
1973 | } |
1974 | EXPORT_SYMBOL_GPL(remove_memory); |
1975 | #endif /* CONFIG_MEMORY_HOTREMOVE */ |
1976 |
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