Commit | Line | Data |
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3947be19 DH |
1 | /* |
2 | * linux/mm/memory_hotplug.c | |
3 | * | |
4 | * Copyright (C) | |
5 | */ | |
6 | ||
3947be19 DH |
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/bootmem.h> | |
13 | #include <linux/compiler.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/pagevec.h> | |
2d1d43f6 | 16 | #include <linux/writeback.h> |
3947be19 DH |
17 | #include <linux/slab.h> |
18 | #include <linux/sysctl.h> | |
19 | #include <linux/cpu.h> | |
20 | #include <linux/memory.h> | |
21 | #include <linux/memory_hotplug.h> | |
22 | #include <linux/highmem.h> | |
23 | #include <linux/vmalloc.h> | |
0a547039 | 24 | #include <linux/ioport.h> |
38837fc7 | 25 | #include <linux/cpuset.h> |
0c0e6195 KH |
26 | #include <linux/delay.h> |
27 | #include <linux/migrate.h> | |
28 | #include <linux/page-isolation.h> | |
3947be19 DH |
29 | |
30 | #include <asm/tlbflush.h> | |
31 | ||
45e0b78b KM |
32 | /* add this memory to iomem resource */ |
33 | static struct resource *register_memory_resource(u64 start, u64 size) | |
34 | { | |
35 | struct resource *res; | |
36 | res = kzalloc(sizeof(struct resource), GFP_KERNEL); | |
37 | BUG_ON(!res); | |
38 | ||
39 | res->name = "System RAM"; | |
40 | res->start = start; | |
41 | res->end = start + size - 1; | |
887c3cb1 | 42 | res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; |
45e0b78b KM |
43 | if (request_resource(&iomem_resource, res) < 0) { |
44 | printk("System RAM resource %llx - %llx cannot be added\n", | |
45 | (unsigned long long)res->start, (unsigned long long)res->end); | |
46 | kfree(res); | |
47 | res = NULL; | |
48 | } | |
49 | return res; | |
50 | } | |
51 | ||
52 | static void release_memory_resource(struct resource *res) | |
53 | { | |
54 | if (!res) | |
55 | return; | |
56 | release_resource(res); | |
57 | kfree(res); | |
58 | return; | |
59 | } | |
60 | ||
61 | ||
53947027 | 62 | #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE |
718127cc | 63 | static int __add_zone(struct zone *zone, unsigned long phys_start_pfn) |
3947be19 DH |
64 | { |
65 | struct pglist_data *pgdat = zone->zone_pgdat; | |
66 | int nr_pages = PAGES_PER_SECTION; | |
67 | int nid = pgdat->node_id; | |
68 | int zone_type; | |
69 | ||
70 | zone_type = zone - pgdat->node_zones; | |
13466c84 | 71 | if (!zone->wait_table) { |
718127cc | 72 | int ret = 0; |
a2f3aa02 DH |
73 | ret = init_currently_empty_zone(zone, phys_start_pfn, |
74 | nr_pages, MEMMAP_HOTPLUG); | |
718127cc YG |
75 | if (ret < 0) |
76 | return ret; | |
77 | } | |
a2f3aa02 DH |
78 | memmap_init_zone(nr_pages, nid, zone_type, |
79 | phys_start_pfn, MEMMAP_HOTPLUG); | |
718127cc | 80 | return 0; |
3947be19 DH |
81 | } |
82 | ||
3947be19 DH |
83 | static int __add_section(struct zone *zone, unsigned long phys_start_pfn) |
84 | { | |
3947be19 | 85 | int nr_pages = PAGES_PER_SECTION; |
3947be19 DH |
86 | int ret; |
87 | ||
ebd15302 KH |
88 | if (pfn_valid(phys_start_pfn)) |
89 | return -EEXIST; | |
90 | ||
0b0acbec | 91 | ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages); |
3947be19 DH |
92 | |
93 | if (ret < 0) | |
94 | return ret; | |
95 | ||
718127cc YG |
96 | ret = __add_zone(zone, phys_start_pfn); |
97 | ||
98 | if (ret < 0) | |
99 | return ret; | |
100 | ||
3947be19 DH |
101 | return register_new_memory(__pfn_to_section(phys_start_pfn)); |
102 | } | |
103 | ||
ea01ea93 BP |
104 | static int __remove_section(struct zone *zone, struct mem_section *ms) |
105 | { | |
106 | unsigned long flags; | |
107 | struct pglist_data *pgdat = zone->zone_pgdat; | |
108 | int ret = -EINVAL; | |
109 | ||
110 | if (!valid_section(ms)) | |
111 | return ret; | |
112 | ||
113 | ret = unregister_memory_section(ms); | |
114 | if (ret) | |
115 | return ret; | |
116 | ||
117 | pgdat_resize_lock(pgdat, &flags); | |
118 | sparse_remove_one_section(zone, ms); | |
119 | pgdat_resize_unlock(pgdat, &flags); | |
120 | return 0; | |
121 | } | |
122 | ||
3947be19 DH |
123 | /* |
124 | * Reasonably generic function for adding memory. It is | |
125 | * expected that archs that support memory hotplug will | |
126 | * call this function after deciding the zone to which to | |
127 | * add the new pages. | |
128 | */ | |
129 | int __add_pages(struct zone *zone, unsigned long phys_start_pfn, | |
130 | unsigned long nr_pages) | |
131 | { | |
132 | unsigned long i; | |
133 | int err = 0; | |
6f712711 KH |
134 | int start_sec, end_sec; |
135 | /* during initialize mem_map, align hot-added range to section */ | |
136 | start_sec = pfn_to_section_nr(phys_start_pfn); | |
137 | end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1); | |
3947be19 | 138 | |
6f712711 KH |
139 | for (i = start_sec; i <= end_sec; i++) { |
140 | err = __add_section(zone, i << PFN_SECTION_SHIFT); | |
3947be19 | 141 | |
6f712711 | 142 | /* |
183ff22b | 143 | * EEXIST is finally dealt with by ioresource collision |
6f712711 KH |
144 | * check. see add_memory() => register_memory_resource() |
145 | * Warning will be printed if there is collision. | |
bed120c6 JS |
146 | */ |
147 | if (err && (err != -EEXIST)) | |
3947be19 | 148 | break; |
6f712711 | 149 | err = 0; |
3947be19 DH |
150 | } |
151 | ||
152 | return err; | |
153 | } | |
bed120c6 | 154 | EXPORT_SYMBOL_GPL(__add_pages); |
3947be19 | 155 | |
ea01ea93 BP |
156 | /** |
157 | * __remove_pages() - remove sections of pages from a zone | |
158 | * @zone: zone from which pages need to be removed | |
159 | * @phys_start_pfn: starting pageframe (must be aligned to start of a section) | |
160 | * @nr_pages: number of pages to remove (must be multiple of section size) | |
161 | * | |
162 | * Generic helper function to remove section mappings and sysfs entries | |
163 | * for the section of the memory we are removing. Caller needs to make | |
164 | * sure that pages are marked reserved and zones are adjust properly by | |
165 | * calling offline_pages(). | |
166 | */ | |
167 | int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, | |
168 | unsigned long nr_pages) | |
169 | { | |
170 | unsigned long i, ret = 0; | |
171 | int sections_to_remove; | |
172 | ||
173 | /* | |
174 | * We can only remove entire sections | |
175 | */ | |
176 | BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK); | |
177 | BUG_ON(nr_pages % PAGES_PER_SECTION); | |
178 | ||
179 | release_mem_region(phys_start_pfn << PAGE_SHIFT, nr_pages * PAGE_SIZE); | |
180 | ||
181 | sections_to_remove = nr_pages / PAGES_PER_SECTION; | |
182 | for (i = 0; i < sections_to_remove; i++) { | |
183 | unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION; | |
184 | ret = __remove_section(zone, __pfn_to_section(pfn)); | |
185 | if (ret) | |
186 | break; | |
187 | } | |
188 | return ret; | |
189 | } | |
190 | EXPORT_SYMBOL_GPL(__remove_pages); | |
191 | ||
3947be19 DH |
192 | static void grow_zone_span(struct zone *zone, |
193 | unsigned long start_pfn, unsigned long end_pfn) | |
194 | { | |
195 | unsigned long old_zone_end_pfn; | |
196 | ||
197 | zone_span_writelock(zone); | |
198 | ||
199 | old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages; | |
200 | if (start_pfn < zone->zone_start_pfn) | |
201 | zone->zone_start_pfn = start_pfn; | |
202 | ||
25a6df95 YG |
203 | zone->spanned_pages = max(old_zone_end_pfn, end_pfn) - |
204 | zone->zone_start_pfn; | |
3947be19 DH |
205 | |
206 | zone_span_writeunlock(zone); | |
207 | } | |
208 | ||
209 | static void grow_pgdat_span(struct pglist_data *pgdat, | |
210 | unsigned long start_pfn, unsigned long end_pfn) | |
211 | { | |
212 | unsigned long old_pgdat_end_pfn = | |
213 | pgdat->node_start_pfn + pgdat->node_spanned_pages; | |
214 | ||
215 | if (start_pfn < pgdat->node_start_pfn) | |
216 | pgdat->node_start_pfn = start_pfn; | |
217 | ||
25a6df95 YG |
218 | pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) - |
219 | pgdat->node_start_pfn; | |
3947be19 DH |
220 | } |
221 | ||
180c06ef JF |
222 | void online_page(struct page *page) |
223 | { | |
224 | totalram_pages++; | |
225 | num_physpages++; | |
226 | ||
227 | #ifdef CONFIG_HIGHMEM | |
228 | if (PageHighMem(page)) | |
229 | totalhigh_pages++; | |
230 | #endif | |
231 | ||
232 | #ifdef CONFIG_FLATMEM | |
233 | max_mapnr = max(page_to_pfn(page), max_mapnr); | |
234 | #endif | |
235 | ||
236 | ClearPageReserved(page); | |
237 | init_page_count(page); | |
238 | __free_page(page); | |
239 | } | |
240 | ||
75884fb1 KH |
241 | static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, |
242 | void *arg) | |
3947be19 DH |
243 | { |
244 | unsigned long i; | |
75884fb1 KH |
245 | unsigned long onlined_pages = *(unsigned long *)arg; |
246 | struct page *page; | |
247 | if (PageReserved(pfn_to_page(start_pfn))) | |
248 | for (i = 0; i < nr_pages; i++) { | |
249 | page = pfn_to_page(start_pfn + i); | |
250 | online_page(page); | |
251 | onlined_pages++; | |
252 | } | |
253 | *(unsigned long *)arg = onlined_pages; | |
254 | return 0; | |
255 | } | |
256 | ||
257 | ||
258 | int online_pages(unsigned long pfn, unsigned long nr_pages) | |
259 | { | |
3947be19 DH |
260 | unsigned long flags; |
261 | unsigned long onlined_pages = 0; | |
262 | struct zone *zone; | |
6811378e | 263 | int need_zonelists_rebuild = 0; |
7b78d335 YG |
264 | int nid; |
265 | int ret; | |
266 | struct memory_notify arg; | |
267 | ||
268 | arg.start_pfn = pfn; | |
269 | arg.nr_pages = nr_pages; | |
270 | arg.status_change_nid = -1; | |
271 | ||
272 | nid = page_to_nid(pfn_to_page(pfn)); | |
273 | if (node_present_pages(nid) == 0) | |
274 | arg.status_change_nid = nid; | |
3947be19 | 275 | |
7b78d335 YG |
276 | ret = memory_notify(MEM_GOING_ONLINE, &arg); |
277 | ret = notifier_to_errno(ret); | |
278 | if (ret) { | |
279 | memory_notify(MEM_CANCEL_ONLINE, &arg); | |
280 | return ret; | |
281 | } | |
3947be19 DH |
282 | /* |
283 | * This doesn't need a lock to do pfn_to_page(). | |
284 | * The section can't be removed here because of the | |
da19cbcf | 285 | * memory_block->state_mutex. |
3947be19 DH |
286 | */ |
287 | zone = page_zone(pfn_to_page(pfn)); | |
288 | pgdat_resize_lock(zone->zone_pgdat, &flags); | |
289 | grow_zone_span(zone, pfn, pfn + nr_pages); | |
290 | grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages); | |
291 | pgdat_resize_unlock(zone->zone_pgdat, &flags); | |
292 | ||
6811378e YG |
293 | /* |
294 | * If this zone is not populated, then it is not in zonelist. | |
295 | * This means the page allocator ignores this zone. | |
296 | * So, zonelist must be updated after online. | |
297 | */ | |
298 | if (!populated_zone(zone)) | |
299 | need_zonelists_rebuild = 1; | |
300 | ||
75884fb1 KH |
301 | walk_memory_resource(pfn, nr_pages, &onlined_pages, |
302 | online_pages_range); | |
3947be19 | 303 | zone->present_pages += onlined_pages; |
f2937be5 | 304 | zone->zone_pgdat->node_present_pages += onlined_pages; |
3947be19 | 305 | |
61b13993 | 306 | setup_per_zone_pages_min(); |
7ea1530a CL |
307 | if (onlined_pages) { |
308 | kswapd_run(zone_to_nid(zone)); | |
309 | node_set_state(zone_to_nid(zone), N_HIGH_MEMORY); | |
310 | } | |
61b13993 | 311 | |
6811378e YG |
312 | if (need_zonelists_rebuild) |
313 | build_all_zonelists(); | |
5a4d4361 | 314 | vm_total_pages = nr_free_pagecache_pages(); |
2d1d43f6 | 315 | writeback_set_ratelimit(); |
7b78d335 YG |
316 | |
317 | if (onlined_pages) | |
318 | memory_notify(MEM_ONLINE, &arg); | |
319 | ||
3947be19 DH |
320 | return 0; |
321 | } | |
53947027 | 322 | #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ |
bc02af93 | 323 | |
9af3c2de YG |
324 | static pg_data_t *hotadd_new_pgdat(int nid, u64 start) |
325 | { | |
326 | struct pglist_data *pgdat; | |
327 | unsigned long zones_size[MAX_NR_ZONES] = {0}; | |
328 | unsigned long zholes_size[MAX_NR_ZONES] = {0}; | |
329 | unsigned long start_pfn = start >> PAGE_SHIFT; | |
330 | ||
331 | pgdat = arch_alloc_nodedata(nid); | |
332 | if (!pgdat) | |
333 | return NULL; | |
334 | ||
335 | arch_refresh_nodedata(nid, pgdat); | |
336 | ||
337 | /* we can use NODE_DATA(nid) from here */ | |
338 | ||
339 | /* init node's zones as empty zones, we don't have any present pages.*/ | |
340 | free_area_init_node(nid, pgdat, zones_size, start_pfn, zholes_size); | |
341 | ||
342 | return pgdat; | |
343 | } | |
344 | ||
345 | static void rollback_node_hotadd(int nid, pg_data_t *pgdat) | |
346 | { | |
347 | arch_refresh_nodedata(nid, NULL); | |
348 | arch_free_nodedata(pgdat); | |
349 | return; | |
350 | } | |
351 | ||
0a547039 | 352 | |
bc02af93 YG |
353 | int add_memory(int nid, u64 start, u64 size) |
354 | { | |
9af3c2de YG |
355 | pg_data_t *pgdat = NULL; |
356 | int new_pgdat = 0; | |
ebd15302 | 357 | struct resource *res; |
bc02af93 YG |
358 | int ret; |
359 | ||
ebd15302 KH |
360 | res = register_memory_resource(start, size); |
361 | if (!res) | |
362 | return -EEXIST; | |
363 | ||
9af3c2de YG |
364 | if (!node_online(nid)) { |
365 | pgdat = hotadd_new_pgdat(nid, start); | |
366 | if (!pgdat) | |
367 | return -ENOMEM; | |
368 | new_pgdat = 1; | |
9af3c2de YG |
369 | } |
370 | ||
bc02af93 YG |
371 | /* call arch's memory hotadd */ |
372 | ret = arch_add_memory(nid, start, size); | |
373 | ||
9af3c2de YG |
374 | if (ret < 0) |
375 | goto error; | |
376 | ||
0fc44159 | 377 | /* we online node here. we can't roll back from here. */ |
9af3c2de YG |
378 | node_set_online(nid); |
379 | ||
38837fc7 PJ |
380 | cpuset_track_online_nodes(); |
381 | ||
0fc44159 YG |
382 | if (new_pgdat) { |
383 | ret = register_one_node(nid); | |
384 | /* | |
385 | * If sysfs file of new node can't create, cpu on the node | |
386 | * can't be hot-added. There is no rollback way now. | |
387 | * So, check by BUG_ON() to catch it reluctantly.. | |
388 | */ | |
389 | BUG_ON(ret); | |
390 | } | |
391 | ||
9af3c2de YG |
392 | return ret; |
393 | error: | |
394 | /* rollback pgdat allocation and others */ | |
395 | if (new_pgdat) | |
396 | rollback_node_hotadd(nid, pgdat); | |
ebd15302 KH |
397 | if (res) |
398 | release_memory_resource(res); | |
9af3c2de | 399 | |
bc02af93 YG |
400 | return ret; |
401 | } | |
402 | EXPORT_SYMBOL_GPL(add_memory); | |
0c0e6195 KH |
403 | |
404 | #ifdef CONFIG_MEMORY_HOTREMOVE | |
405 | /* | |
406 | * Confirm all pages in a range [start, end) is belongs to the same zone. | |
407 | */ | |
408 | static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn) | |
409 | { | |
410 | unsigned long pfn; | |
411 | struct zone *zone = NULL; | |
412 | struct page *page; | |
413 | int i; | |
414 | for (pfn = start_pfn; | |
415 | pfn < end_pfn; | |
416 | pfn += MAX_ORDER_NR_PAGES) { | |
417 | i = 0; | |
418 | /* This is just a CONFIG_HOLES_IN_ZONE check.*/ | |
419 | while ((i < MAX_ORDER_NR_PAGES) && !pfn_valid_within(pfn + i)) | |
420 | i++; | |
421 | if (i == MAX_ORDER_NR_PAGES) | |
422 | continue; | |
423 | page = pfn_to_page(pfn + i); | |
424 | if (zone && page_zone(page) != zone) | |
425 | return 0; | |
426 | zone = page_zone(page); | |
427 | } | |
428 | return 1; | |
429 | } | |
430 | ||
431 | /* | |
432 | * Scanning pfn is much easier than scanning lru list. | |
433 | * Scan pfn from start to end and Find LRU page. | |
434 | */ | |
435 | int scan_lru_pages(unsigned long start, unsigned long end) | |
436 | { | |
437 | unsigned long pfn; | |
438 | struct page *page; | |
439 | for (pfn = start; pfn < end; pfn++) { | |
440 | if (pfn_valid(pfn)) { | |
441 | page = pfn_to_page(pfn); | |
442 | if (PageLRU(page)) | |
443 | return pfn; | |
444 | } | |
445 | } | |
446 | return 0; | |
447 | } | |
448 | ||
449 | static struct page * | |
450 | hotremove_migrate_alloc(struct page *page, | |
451 | unsigned long private, | |
452 | int **x) | |
453 | { | |
454 | /* This should be improoooooved!! */ | |
455 | return alloc_page(GFP_HIGHUSER_PAGECACHE); | |
456 | } | |
457 | ||
458 | ||
459 | #define NR_OFFLINE_AT_ONCE_PAGES (256) | |
460 | static int | |
461 | do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) | |
462 | { | |
463 | unsigned long pfn; | |
464 | struct page *page; | |
465 | int move_pages = NR_OFFLINE_AT_ONCE_PAGES; | |
466 | int not_managed = 0; | |
467 | int ret = 0; | |
468 | LIST_HEAD(source); | |
469 | ||
470 | for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) { | |
471 | if (!pfn_valid(pfn)) | |
472 | continue; | |
473 | page = pfn_to_page(pfn); | |
474 | if (!page_count(page)) | |
475 | continue; | |
476 | /* | |
477 | * We can skip free pages. And we can only deal with pages on | |
478 | * LRU. | |
479 | */ | |
480 | ret = isolate_lru_page(page, &source); | |
481 | if (!ret) { /* Success */ | |
482 | move_pages--; | |
483 | } else { | |
484 | /* Becasue we don't have big zone->lock. we should | |
485 | check this again here. */ | |
486 | if (page_count(page)) | |
487 | not_managed++; | |
488 | #ifdef CONFIG_DEBUG_VM | |
489 | printk(KERN_INFO "removing from LRU failed" | |
490 | " %lx/%d/%lx\n", | |
491 | pfn, page_count(page), page->flags); | |
492 | #endif | |
493 | } | |
494 | } | |
495 | ret = -EBUSY; | |
496 | if (not_managed) { | |
497 | if (!list_empty(&source)) | |
498 | putback_lru_pages(&source); | |
499 | goto out; | |
500 | } | |
501 | ret = 0; | |
502 | if (list_empty(&source)) | |
503 | goto out; | |
504 | /* this function returns # of failed pages */ | |
505 | ret = migrate_pages(&source, hotremove_migrate_alloc, 0); | |
506 | ||
507 | out: | |
508 | return ret; | |
509 | } | |
510 | ||
511 | /* | |
512 | * remove from free_area[] and mark all as Reserved. | |
513 | */ | |
514 | static int | |
515 | offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages, | |
516 | void *data) | |
517 | { | |
518 | __offline_isolated_pages(start, start + nr_pages); | |
519 | return 0; | |
520 | } | |
521 | ||
522 | static void | |
523 | offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) | |
524 | { | |
525 | walk_memory_resource(start_pfn, end_pfn - start_pfn, NULL, | |
526 | offline_isolated_pages_cb); | |
527 | } | |
528 | ||
529 | /* | |
530 | * Check all pages in range, recoreded as memory resource, are isolated. | |
531 | */ | |
532 | static int | |
533 | check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages, | |
534 | void *data) | |
535 | { | |
536 | int ret; | |
537 | long offlined = *(long *)data; | |
538 | ret = test_pages_isolated(start_pfn, start_pfn + nr_pages); | |
539 | offlined = nr_pages; | |
540 | if (!ret) | |
541 | *(long *)data += offlined; | |
542 | return ret; | |
543 | } | |
544 | ||
545 | static long | |
546 | check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn) | |
547 | { | |
548 | long offlined = 0; | |
549 | int ret; | |
550 | ||
551 | ret = walk_memory_resource(start_pfn, end_pfn - start_pfn, &offlined, | |
552 | check_pages_isolated_cb); | |
553 | if (ret < 0) | |
554 | offlined = (long)ret; | |
555 | return offlined; | |
556 | } | |
557 | ||
0c0e6195 KH |
558 | int offline_pages(unsigned long start_pfn, |
559 | unsigned long end_pfn, unsigned long timeout) | |
560 | { | |
561 | unsigned long pfn, nr_pages, expire; | |
562 | long offlined_pages; | |
7b78d335 | 563 | int ret, drain, retry_max, node; |
0c0e6195 | 564 | struct zone *zone; |
7b78d335 | 565 | struct memory_notify arg; |
0c0e6195 KH |
566 | |
567 | BUG_ON(start_pfn >= end_pfn); | |
568 | /* at least, alignment against pageblock is necessary */ | |
569 | if (!IS_ALIGNED(start_pfn, pageblock_nr_pages)) | |
570 | return -EINVAL; | |
571 | if (!IS_ALIGNED(end_pfn, pageblock_nr_pages)) | |
572 | return -EINVAL; | |
573 | /* This makes hotplug much easier...and readable. | |
574 | we assume this for now. .*/ | |
575 | if (!test_pages_in_a_zone(start_pfn, end_pfn)) | |
576 | return -EINVAL; | |
7b78d335 YG |
577 | |
578 | zone = page_zone(pfn_to_page(start_pfn)); | |
579 | node = zone_to_nid(zone); | |
580 | nr_pages = end_pfn - start_pfn; | |
581 | ||
0c0e6195 KH |
582 | /* set above range as isolated */ |
583 | ret = start_isolate_page_range(start_pfn, end_pfn); | |
584 | if (ret) | |
585 | return ret; | |
7b78d335 YG |
586 | |
587 | arg.start_pfn = start_pfn; | |
588 | arg.nr_pages = nr_pages; | |
589 | arg.status_change_nid = -1; | |
590 | if (nr_pages >= node_present_pages(node)) | |
591 | arg.status_change_nid = node; | |
592 | ||
593 | ret = memory_notify(MEM_GOING_OFFLINE, &arg); | |
594 | ret = notifier_to_errno(ret); | |
595 | if (ret) | |
596 | goto failed_removal; | |
597 | ||
0c0e6195 KH |
598 | pfn = start_pfn; |
599 | expire = jiffies + timeout; | |
600 | drain = 0; | |
601 | retry_max = 5; | |
602 | repeat: | |
603 | /* start memory hot removal */ | |
604 | ret = -EAGAIN; | |
605 | if (time_after(jiffies, expire)) | |
606 | goto failed_removal; | |
607 | ret = -EINTR; | |
608 | if (signal_pending(current)) | |
609 | goto failed_removal; | |
610 | ret = 0; | |
611 | if (drain) { | |
612 | lru_add_drain_all(); | |
613 | flush_scheduled_work(); | |
614 | cond_resched(); | |
9f8f2172 | 615 | drain_all_pages(); |
0c0e6195 KH |
616 | } |
617 | ||
618 | pfn = scan_lru_pages(start_pfn, end_pfn); | |
619 | if (pfn) { /* We have page on LRU */ | |
620 | ret = do_migrate_range(pfn, end_pfn); | |
621 | if (!ret) { | |
622 | drain = 1; | |
623 | goto repeat; | |
624 | } else { | |
625 | if (ret < 0) | |
626 | if (--retry_max == 0) | |
627 | goto failed_removal; | |
628 | yield(); | |
629 | drain = 1; | |
630 | goto repeat; | |
631 | } | |
632 | } | |
633 | /* drain all zone's lru pagevec, this is asyncronous... */ | |
634 | lru_add_drain_all(); | |
635 | flush_scheduled_work(); | |
636 | yield(); | |
637 | /* drain pcp pages , this is synchrouns. */ | |
9f8f2172 | 638 | drain_all_pages(); |
0c0e6195 KH |
639 | /* check again */ |
640 | offlined_pages = check_pages_isolated(start_pfn, end_pfn); | |
641 | if (offlined_pages < 0) { | |
642 | ret = -EBUSY; | |
643 | goto failed_removal; | |
644 | } | |
645 | printk(KERN_INFO "Offlined Pages %ld\n", offlined_pages); | |
646 | /* Ok, all of our target is islaoted. | |
647 | We cannot do rollback at this point. */ | |
648 | offline_isolated_pages(start_pfn, end_pfn); | |
dbc0e4ce KH |
649 | /* reset pagetype flags and makes migrate type to be MOVABLE */ |
650 | undo_isolate_page_range(start_pfn, end_pfn); | |
0c0e6195 | 651 | /* removal success */ |
0c0e6195 KH |
652 | zone->present_pages -= offlined_pages; |
653 | zone->zone_pgdat->node_present_pages -= offlined_pages; | |
654 | totalram_pages -= offlined_pages; | |
655 | num_physpages -= offlined_pages; | |
7b78d335 | 656 | |
0c0e6195 KH |
657 | vm_total_pages = nr_free_pagecache_pages(); |
658 | writeback_set_ratelimit(); | |
7b78d335 YG |
659 | |
660 | memory_notify(MEM_OFFLINE, &arg); | |
0c0e6195 KH |
661 | return 0; |
662 | ||
663 | failed_removal: | |
664 | printk(KERN_INFO "memory offlining %lx to %lx failed\n", | |
665 | start_pfn, end_pfn); | |
7b78d335 | 666 | memory_notify(MEM_CANCEL_OFFLINE, &arg); |
0c0e6195 KH |
667 | /* pushback to free area */ |
668 | undo_isolate_page_range(start_pfn, end_pfn); | |
7b78d335 | 669 | |
0c0e6195 KH |
670 | return ret; |
671 | } | |
48e94196 KH |
672 | #else |
673 | int remove_memory(u64 start, u64 size) | |
674 | { | |
675 | return -EINVAL; | |
676 | } | |
677 | EXPORT_SYMBOL_GPL(remove_memory); | |
0c0e6195 | 678 | #endif /* CONFIG_MEMORY_HOTREMOVE */ |