Commit | Line | Data |
---|---|---|
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> |
0c0e6195 KH |
25 | #include <linux/delay.h> |
26 | #include <linux/migrate.h> | |
27 | #include <linux/page-isolation.h> | |
71088785 | 28 | #include <linux/pfn.h> |
6ad696d2 | 29 | #include <linux/suspend.h> |
3947be19 DH |
30 | |
31 | #include <asm/tlbflush.h> | |
32 | ||
1e5ad9a3 AB |
33 | #include "internal.h" |
34 | ||
45e0b78b KM |
35 | /* add this memory to iomem resource */ |
36 | static struct resource *register_memory_resource(u64 start, u64 size) | |
37 | { | |
38 | struct resource *res; | |
39 | res = kzalloc(sizeof(struct resource), GFP_KERNEL); | |
40 | BUG_ON(!res); | |
41 | ||
42 | res->name = "System RAM"; | |
43 | res->start = start; | |
44 | res->end = start + size - 1; | |
887c3cb1 | 45 | res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; |
45e0b78b KM |
46 | if (request_resource(&iomem_resource, res) < 0) { |
47 | printk("System RAM resource %llx - %llx cannot be added\n", | |
48 | (unsigned long long)res->start, (unsigned long long)res->end); | |
49 | kfree(res); | |
50 | res = NULL; | |
51 | } | |
52 | return res; | |
53 | } | |
54 | ||
55 | static void release_memory_resource(struct resource *res) | |
56 | { | |
57 | if (!res) | |
58 | return; | |
59 | release_resource(res); | |
60 | kfree(res); | |
61 | return; | |
62 | } | |
63 | ||
53947027 | 64 | #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE |
04753278 | 65 | #ifndef CONFIG_SPARSEMEM_VMEMMAP |
af370fb8 | 66 | static void get_page_bootmem(unsigned long info, struct page *page, int type) |
04753278 | 67 | { |
af370fb8 | 68 | atomic_set(&page->_mapcount, type); |
04753278 YG |
69 | SetPagePrivate(page); |
70 | set_page_private(page, info); | |
71 | atomic_inc(&page->_count); | |
72 | } | |
73 | ||
74 | void put_page_bootmem(struct page *page) | |
75 | { | |
af370fb8 | 76 | int type; |
04753278 | 77 | |
af370fb8 YG |
78 | type = atomic_read(&page->_mapcount); |
79 | BUG_ON(type >= -1); | |
04753278 YG |
80 | |
81 | if (atomic_dec_return(&page->_count) == 1) { | |
82 | ClearPagePrivate(page); | |
83 | set_page_private(page, 0); | |
84 | reset_page_mapcount(page); | |
85 | __free_pages_bootmem(page, 0); | |
86 | } | |
87 | ||
88 | } | |
89 | ||
d92bc318 | 90 | static void register_page_bootmem_info_section(unsigned long start_pfn) |
04753278 YG |
91 | { |
92 | unsigned long *usemap, mapsize, section_nr, i; | |
93 | struct mem_section *ms; | |
94 | struct page *page, *memmap; | |
95 | ||
96 | if (!pfn_valid(start_pfn)) | |
97 | return; | |
98 | ||
99 | section_nr = pfn_to_section_nr(start_pfn); | |
100 | ms = __nr_to_section(section_nr); | |
101 | ||
102 | /* Get section's memmap address */ | |
103 | memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); | |
104 | ||
105 | /* | |
106 | * Get page for the memmap's phys address | |
107 | * XXX: need more consideration for sparse_vmemmap... | |
108 | */ | |
109 | page = virt_to_page(memmap); | |
110 | mapsize = sizeof(struct page) * PAGES_PER_SECTION; | |
111 | mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT; | |
112 | ||
113 | /* remember memmap's page */ | |
114 | for (i = 0; i < mapsize; i++, page++) | |
115 | get_page_bootmem(section_nr, page, SECTION_INFO); | |
116 | ||
117 | usemap = __nr_to_section(section_nr)->pageblock_flags; | |
118 | page = virt_to_page(usemap); | |
119 | ||
120 | mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT; | |
121 | ||
122 | for (i = 0; i < mapsize; i++, page++) | |
af370fb8 | 123 | get_page_bootmem(section_nr, page, MIX_SECTION_INFO); |
04753278 YG |
124 | |
125 | } | |
126 | ||
127 | void register_page_bootmem_info_node(struct pglist_data *pgdat) | |
128 | { | |
129 | unsigned long i, pfn, end_pfn, nr_pages; | |
130 | int node = pgdat->node_id; | |
131 | struct page *page; | |
132 | struct zone *zone; | |
133 | ||
134 | nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT; | |
135 | page = virt_to_page(pgdat); | |
136 | ||
137 | for (i = 0; i < nr_pages; i++, page++) | |
138 | get_page_bootmem(node, page, NODE_INFO); | |
139 | ||
140 | zone = &pgdat->node_zones[0]; | |
141 | for (; zone < pgdat->node_zones + MAX_NR_ZONES - 1; zone++) { | |
142 | if (zone->wait_table) { | |
143 | nr_pages = zone->wait_table_hash_nr_entries | |
144 | * sizeof(wait_queue_head_t); | |
145 | nr_pages = PAGE_ALIGN(nr_pages) >> PAGE_SHIFT; | |
146 | page = virt_to_page(zone->wait_table); | |
147 | ||
148 | for (i = 0; i < nr_pages; i++, page++) | |
149 | get_page_bootmem(node, page, NODE_INFO); | |
150 | } | |
151 | } | |
152 | ||
153 | pfn = pgdat->node_start_pfn; | |
154 | end_pfn = pfn + pgdat->node_spanned_pages; | |
155 | ||
156 | /* register_section info */ | |
157 | for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) | |
158 | register_page_bootmem_info_section(pfn); | |
159 | ||
160 | } | |
161 | #endif /* !CONFIG_SPARSEMEM_VMEMMAP */ | |
162 | ||
76cdd58e HC |
163 | static void grow_zone_span(struct zone *zone, unsigned long start_pfn, |
164 | unsigned long end_pfn) | |
165 | { | |
166 | unsigned long old_zone_end_pfn; | |
167 | ||
168 | zone_span_writelock(zone); | |
169 | ||
170 | old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages; | |
171 | if (start_pfn < zone->zone_start_pfn) | |
172 | zone->zone_start_pfn = start_pfn; | |
173 | ||
174 | zone->spanned_pages = max(old_zone_end_pfn, end_pfn) - | |
175 | zone->zone_start_pfn; | |
176 | ||
177 | zone_span_writeunlock(zone); | |
178 | } | |
179 | ||
180 | static void grow_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn, | |
181 | unsigned long end_pfn) | |
182 | { | |
183 | unsigned long old_pgdat_end_pfn = | |
184 | pgdat->node_start_pfn + pgdat->node_spanned_pages; | |
185 | ||
186 | if (start_pfn < pgdat->node_start_pfn) | |
187 | pgdat->node_start_pfn = start_pfn; | |
188 | ||
189 | pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) - | |
190 | pgdat->node_start_pfn; | |
191 | } | |
192 | ||
31168481 | 193 | static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn) |
3947be19 DH |
194 | { |
195 | struct pglist_data *pgdat = zone->zone_pgdat; | |
196 | int nr_pages = PAGES_PER_SECTION; | |
197 | int nid = pgdat->node_id; | |
198 | int zone_type; | |
76cdd58e | 199 | unsigned long flags; |
3947be19 DH |
200 | |
201 | zone_type = zone - pgdat->node_zones; | |
76cdd58e HC |
202 | if (!zone->wait_table) { |
203 | int ret; | |
204 | ||
205 | ret = init_currently_empty_zone(zone, phys_start_pfn, | |
206 | nr_pages, MEMMAP_HOTPLUG); | |
207 | if (ret) | |
208 | return ret; | |
209 | } | |
210 | pgdat_resize_lock(zone->zone_pgdat, &flags); | |
211 | grow_zone_span(zone, phys_start_pfn, phys_start_pfn + nr_pages); | |
212 | grow_pgdat_span(zone->zone_pgdat, phys_start_pfn, | |
213 | phys_start_pfn + nr_pages); | |
214 | pgdat_resize_unlock(zone->zone_pgdat, &flags); | |
a2f3aa02 DH |
215 | memmap_init_zone(nr_pages, nid, zone_type, |
216 | phys_start_pfn, MEMMAP_HOTPLUG); | |
718127cc | 217 | return 0; |
3947be19 DH |
218 | } |
219 | ||
c04fc586 GH |
220 | static int __meminit __add_section(int nid, struct zone *zone, |
221 | unsigned long phys_start_pfn) | |
3947be19 | 222 | { |
3947be19 | 223 | int nr_pages = PAGES_PER_SECTION; |
3947be19 DH |
224 | int ret; |
225 | ||
ebd15302 KH |
226 | if (pfn_valid(phys_start_pfn)) |
227 | return -EEXIST; | |
228 | ||
0b0acbec | 229 | ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages); |
3947be19 DH |
230 | |
231 | if (ret < 0) | |
232 | return ret; | |
233 | ||
718127cc YG |
234 | ret = __add_zone(zone, phys_start_pfn); |
235 | ||
236 | if (ret < 0) | |
237 | return ret; | |
238 | ||
c04fc586 | 239 | return register_new_memory(nid, __pfn_to_section(phys_start_pfn)); |
3947be19 DH |
240 | } |
241 | ||
0c0a4a51 YG |
242 | #ifdef CONFIG_SPARSEMEM_VMEMMAP |
243 | static int __remove_section(struct zone *zone, struct mem_section *ms) | |
244 | { | |
245 | /* | |
246 | * XXX: Freeing memmap with vmemmap is not implement yet. | |
247 | * This should be removed later. | |
248 | */ | |
249 | return -EBUSY; | |
250 | } | |
251 | #else | |
ea01ea93 BP |
252 | static int __remove_section(struct zone *zone, struct mem_section *ms) |
253 | { | |
254 | unsigned long flags; | |
255 | struct pglist_data *pgdat = zone->zone_pgdat; | |
256 | int ret = -EINVAL; | |
257 | ||
258 | if (!valid_section(ms)) | |
259 | return ret; | |
260 | ||
261 | ret = unregister_memory_section(ms); | |
262 | if (ret) | |
263 | return ret; | |
264 | ||
265 | pgdat_resize_lock(pgdat, &flags); | |
266 | sparse_remove_one_section(zone, ms); | |
267 | pgdat_resize_unlock(pgdat, &flags); | |
268 | return 0; | |
269 | } | |
0c0a4a51 | 270 | #endif |
ea01ea93 | 271 | |
3947be19 DH |
272 | /* |
273 | * Reasonably generic function for adding memory. It is | |
274 | * expected that archs that support memory hotplug will | |
275 | * call this function after deciding the zone to which to | |
276 | * add the new pages. | |
277 | */ | |
c04fc586 GH |
278 | int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn, |
279 | unsigned long nr_pages) | |
3947be19 DH |
280 | { |
281 | unsigned long i; | |
282 | int err = 0; | |
6f712711 KH |
283 | int start_sec, end_sec; |
284 | /* during initialize mem_map, align hot-added range to section */ | |
285 | start_sec = pfn_to_section_nr(phys_start_pfn); | |
286 | end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1); | |
3947be19 | 287 | |
6f712711 | 288 | for (i = start_sec; i <= end_sec; i++) { |
c04fc586 | 289 | err = __add_section(nid, zone, i << PFN_SECTION_SHIFT); |
3947be19 | 290 | |
6f712711 | 291 | /* |
183ff22b | 292 | * EEXIST is finally dealt with by ioresource collision |
6f712711 KH |
293 | * check. see add_memory() => register_memory_resource() |
294 | * Warning will be printed if there is collision. | |
bed120c6 JS |
295 | */ |
296 | if (err && (err != -EEXIST)) | |
3947be19 | 297 | break; |
6f712711 | 298 | err = 0; |
3947be19 DH |
299 | } |
300 | ||
301 | return err; | |
302 | } | |
bed120c6 | 303 | EXPORT_SYMBOL_GPL(__add_pages); |
3947be19 | 304 | |
ea01ea93 BP |
305 | /** |
306 | * __remove_pages() - remove sections of pages from a zone | |
307 | * @zone: zone from which pages need to be removed | |
308 | * @phys_start_pfn: starting pageframe (must be aligned to start of a section) | |
309 | * @nr_pages: number of pages to remove (must be multiple of section size) | |
310 | * | |
311 | * Generic helper function to remove section mappings and sysfs entries | |
312 | * for the section of the memory we are removing. Caller needs to make | |
313 | * sure that pages are marked reserved and zones are adjust properly by | |
314 | * calling offline_pages(). | |
315 | */ | |
316 | int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, | |
317 | unsigned long nr_pages) | |
318 | { | |
319 | unsigned long i, ret = 0; | |
320 | int sections_to_remove; | |
321 | ||
322 | /* | |
323 | * We can only remove entire sections | |
324 | */ | |
325 | BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK); | |
326 | BUG_ON(nr_pages % PAGES_PER_SECTION); | |
327 | ||
ea01ea93 BP |
328 | sections_to_remove = nr_pages / PAGES_PER_SECTION; |
329 | for (i = 0; i < sections_to_remove; i++) { | |
330 | unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION; | |
de7f0cba NF |
331 | release_mem_region(pfn << PAGE_SHIFT, |
332 | PAGES_PER_SECTION << PAGE_SHIFT); | |
ea01ea93 BP |
333 | ret = __remove_section(zone, __pfn_to_section(pfn)); |
334 | if (ret) | |
335 | break; | |
336 | } | |
337 | return ret; | |
338 | } | |
339 | EXPORT_SYMBOL_GPL(__remove_pages); | |
340 | ||
180c06ef JF |
341 | void online_page(struct page *page) |
342 | { | |
4738e1b9 JB |
343 | unsigned long pfn = page_to_pfn(page); |
344 | ||
180c06ef | 345 | totalram_pages++; |
4738e1b9 JB |
346 | if (pfn >= num_physpages) |
347 | num_physpages = pfn + 1; | |
180c06ef JF |
348 | |
349 | #ifdef CONFIG_HIGHMEM | |
350 | if (PageHighMem(page)) | |
351 | totalhigh_pages++; | |
352 | #endif | |
353 | ||
354 | #ifdef CONFIG_FLATMEM | |
355 | max_mapnr = max(page_to_pfn(page), max_mapnr); | |
356 | #endif | |
357 | ||
358 | ClearPageReserved(page); | |
359 | init_page_count(page); | |
360 | __free_page(page); | |
361 | } | |
362 | ||
75884fb1 KH |
363 | static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, |
364 | void *arg) | |
3947be19 DH |
365 | { |
366 | unsigned long i; | |
75884fb1 KH |
367 | unsigned long onlined_pages = *(unsigned long *)arg; |
368 | struct page *page; | |
369 | if (PageReserved(pfn_to_page(start_pfn))) | |
370 | for (i = 0; i < nr_pages; i++) { | |
371 | page = pfn_to_page(start_pfn + i); | |
372 | online_page(page); | |
373 | onlined_pages++; | |
374 | } | |
375 | *(unsigned long *)arg = onlined_pages; | |
376 | return 0; | |
377 | } | |
378 | ||
379 | ||
380 | int online_pages(unsigned long pfn, unsigned long nr_pages) | |
381 | { | |
3947be19 DH |
382 | unsigned long onlined_pages = 0; |
383 | struct zone *zone; | |
6811378e | 384 | int need_zonelists_rebuild = 0; |
7b78d335 YG |
385 | int nid; |
386 | int ret; | |
387 | struct memory_notify arg; | |
388 | ||
389 | arg.start_pfn = pfn; | |
390 | arg.nr_pages = nr_pages; | |
391 | arg.status_change_nid = -1; | |
392 | ||
393 | nid = page_to_nid(pfn_to_page(pfn)); | |
394 | if (node_present_pages(nid) == 0) | |
395 | arg.status_change_nid = nid; | |
3947be19 | 396 | |
7b78d335 YG |
397 | ret = memory_notify(MEM_GOING_ONLINE, &arg); |
398 | ret = notifier_to_errno(ret); | |
399 | if (ret) { | |
400 | memory_notify(MEM_CANCEL_ONLINE, &arg); | |
401 | return ret; | |
402 | } | |
3947be19 DH |
403 | /* |
404 | * This doesn't need a lock to do pfn_to_page(). | |
405 | * The section can't be removed here because of the | |
da19cbcf | 406 | * memory_block->state_mutex. |
3947be19 DH |
407 | */ |
408 | zone = page_zone(pfn_to_page(pfn)); | |
6811378e YG |
409 | /* |
410 | * If this zone is not populated, then it is not in zonelist. | |
411 | * This means the page allocator ignores this zone. | |
412 | * So, zonelist must be updated after online. | |
413 | */ | |
414 | if (!populated_zone(zone)) | |
415 | need_zonelists_rebuild = 1; | |
416 | ||
908eedc6 | 417 | ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages, |
75884fb1 | 418 | online_pages_range); |
fd8a4221 GL |
419 | if (ret) { |
420 | printk(KERN_DEBUG "online_pages %lx at %lx failed\n", | |
421 | nr_pages, pfn); | |
422 | memory_notify(MEM_CANCEL_ONLINE, &arg); | |
423 | return ret; | |
424 | } | |
425 | ||
3947be19 | 426 | zone->present_pages += onlined_pages; |
f2937be5 | 427 | zone->zone_pgdat->node_present_pages += onlined_pages; |
3947be19 | 428 | |
112067f0 | 429 | zone_pcp_update(zone); |
bc75d33f | 430 | setup_per_zone_wmarks(); |
bce7394a | 431 | calculate_zone_inactive_ratio(zone); |
7ea1530a CL |
432 | if (onlined_pages) { |
433 | kswapd_run(zone_to_nid(zone)); | |
434 | node_set_state(zone_to_nid(zone), N_HIGH_MEMORY); | |
435 | } | |
61b13993 | 436 | |
6811378e YG |
437 | if (need_zonelists_rebuild) |
438 | build_all_zonelists(); | |
2f7f24ec KL |
439 | else |
440 | vm_total_pages = nr_free_pagecache_pages(); | |
441 | ||
2d1d43f6 | 442 | writeback_set_ratelimit(); |
7b78d335 YG |
443 | |
444 | if (onlined_pages) | |
445 | memory_notify(MEM_ONLINE, &arg); | |
446 | ||
3947be19 DH |
447 | return 0; |
448 | } | |
53947027 | 449 | #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ |
bc02af93 | 450 | |
e1319331 HS |
451 | /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ |
452 | static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) | |
9af3c2de YG |
453 | { |
454 | struct pglist_data *pgdat; | |
455 | unsigned long zones_size[MAX_NR_ZONES] = {0}; | |
456 | unsigned long zholes_size[MAX_NR_ZONES] = {0}; | |
457 | unsigned long start_pfn = start >> PAGE_SHIFT; | |
458 | ||
459 | pgdat = arch_alloc_nodedata(nid); | |
460 | if (!pgdat) | |
461 | return NULL; | |
462 | ||
463 | arch_refresh_nodedata(nid, pgdat); | |
464 | ||
465 | /* we can use NODE_DATA(nid) from here */ | |
466 | ||
467 | /* init node's zones as empty zones, we don't have any present pages.*/ | |
9109fb7b | 468 | free_area_init_node(nid, zones_size, start_pfn, zholes_size); |
9af3c2de YG |
469 | |
470 | return pgdat; | |
471 | } | |
472 | ||
473 | static void rollback_node_hotadd(int nid, pg_data_t *pgdat) | |
474 | { | |
475 | arch_refresh_nodedata(nid, NULL); | |
476 | arch_free_nodedata(pgdat); | |
477 | return; | |
478 | } | |
479 | ||
0a547039 | 480 | |
31168481 AV |
481 | /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ |
482 | int __ref add_memory(int nid, u64 start, u64 size) | |
bc02af93 | 483 | { |
9af3c2de YG |
484 | pg_data_t *pgdat = NULL; |
485 | int new_pgdat = 0; | |
ebd15302 | 486 | struct resource *res; |
bc02af93 YG |
487 | int ret; |
488 | ||
6ad696d2 AK |
489 | lock_system_sleep(); |
490 | ||
ebd15302 | 491 | res = register_memory_resource(start, size); |
6ad696d2 | 492 | ret = -EEXIST; |
ebd15302 | 493 | if (!res) |
6ad696d2 | 494 | goto out; |
ebd15302 | 495 | |
9af3c2de YG |
496 | if (!node_online(nid)) { |
497 | pgdat = hotadd_new_pgdat(nid, start); | |
6ad696d2 | 498 | ret = -ENOMEM; |
9af3c2de | 499 | if (!pgdat) |
6ad696d2 | 500 | goto out; |
9af3c2de | 501 | new_pgdat = 1; |
9af3c2de YG |
502 | } |
503 | ||
bc02af93 YG |
504 | /* call arch's memory hotadd */ |
505 | ret = arch_add_memory(nid, start, size); | |
506 | ||
9af3c2de YG |
507 | if (ret < 0) |
508 | goto error; | |
509 | ||
0fc44159 | 510 | /* we online node here. we can't roll back from here. */ |
9af3c2de YG |
511 | node_set_online(nid); |
512 | ||
0fc44159 YG |
513 | if (new_pgdat) { |
514 | ret = register_one_node(nid); | |
515 | /* | |
516 | * If sysfs file of new node can't create, cpu on the node | |
517 | * can't be hot-added. There is no rollback way now. | |
518 | * So, check by BUG_ON() to catch it reluctantly.. | |
519 | */ | |
520 | BUG_ON(ret); | |
521 | } | |
522 | ||
6ad696d2 AK |
523 | goto out; |
524 | ||
9af3c2de YG |
525 | error: |
526 | /* rollback pgdat allocation and others */ | |
527 | if (new_pgdat) | |
528 | rollback_node_hotadd(nid, pgdat); | |
ebd15302 KH |
529 | if (res) |
530 | release_memory_resource(res); | |
9af3c2de | 531 | |
6ad696d2 AK |
532 | out: |
533 | unlock_system_sleep(); | |
bc02af93 YG |
534 | return ret; |
535 | } | |
536 | EXPORT_SYMBOL_GPL(add_memory); | |
0c0e6195 KH |
537 | |
538 | #ifdef CONFIG_MEMORY_HOTREMOVE | |
5c755e9f BP |
539 | /* |
540 | * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy | |
541 | * set and the size of the free page is given by page_order(). Using this, | |
542 | * the function determines if the pageblock contains only free pages. | |
543 | * Due to buddy contraints, a free page at least the size of a pageblock will | |
544 | * be located at the start of the pageblock | |
545 | */ | |
546 | static inline int pageblock_free(struct page *page) | |
547 | { | |
548 | return PageBuddy(page) && page_order(page) >= pageblock_order; | |
549 | } | |
550 | ||
551 | /* Return the start of the next active pageblock after a given page */ | |
552 | static struct page *next_active_pageblock(struct page *page) | |
553 | { | |
554 | int pageblocks_stride; | |
555 | ||
556 | /* Ensure the starting page is pageblock-aligned */ | |
557 | BUG_ON(page_to_pfn(page) & (pageblock_nr_pages - 1)); | |
558 | ||
559 | /* Move forward by at least 1 * pageblock_nr_pages */ | |
560 | pageblocks_stride = 1; | |
561 | ||
562 | /* If the entire pageblock is free, move to the end of free page */ | |
563 | if (pageblock_free(page)) | |
564 | pageblocks_stride += page_order(page) - pageblock_order; | |
565 | ||
566 | return page + (pageblocks_stride * pageblock_nr_pages); | |
567 | } | |
568 | ||
569 | /* Checks if this range of memory is likely to be hot-removable. */ | |
570 | int is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages) | |
571 | { | |
572 | int type; | |
573 | struct page *page = pfn_to_page(start_pfn); | |
574 | struct page *end_page = page + nr_pages; | |
575 | ||
576 | /* Check the starting page of each pageblock within the range */ | |
577 | for (; page < end_page; page = next_active_pageblock(page)) { | |
578 | type = get_pageblock_migratetype(page); | |
579 | ||
580 | /* | |
581 | * A pageblock containing MOVABLE or free pages is considered | |
582 | * removable | |
583 | */ | |
584 | if (type != MIGRATE_MOVABLE && !pageblock_free(page)) | |
585 | return 0; | |
586 | ||
587 | /* | |
588 | * A pageblock starting with a PageReserved page is not | |
589 | * considered removable. | |
590 | */ | |
591 | if (PageReserved(page)) | |
592 | return 0; | |
593 | } | |
594 | ||
595 | /* All pageblocks in the memory block are likely to be hot-removable */ | |
596 | return 1; | |
597 | } | |
598 | ||
0c0e6195 KH |
599 | /* |
600 | * Confirm all pages in a range [start, end) is belongs to the same zone. | |
601 | */ | |
602 | static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn) | |
603 | { | |
604 | unsigned long pfn; | |
605 | struct zone *zone = NULL; | |
606 | struct page *page; | |
607 | int i; | |
608 | for (pfn = start_pfn; | |
609 | pfn < end_pfn; | |
610 | pfn += MAX_ORDER_NR_PAGES) { | |
611 | i = 0; | |
612 | /* This is just a CONFIG_HOLES_IN_ZONE check.*/ | |
613 | while ((i < MAX_ORDER_NR_PAGES) && !pfn_valid_within(pfn + i)) | |
614 | i++; | |
615 | if (i == MAX_ORDER_NR_PAGES) | |
616 | continue; | |
617 | page = pfn_to_page(pfn + i); | |
618 | if (zone && page_zone(page) != zone) | |
619 | return 0; | |
620 | zone = page_zone(page); | |
621 | } | |
622 | return 1; | |
623 | } | |
624 | ||
625 | /* | |
626 | * Scanning pfn is much easier than scanning lru list. | |
627 | * Scan pfn from start to end and Find LRU page. | |
628 | */ | |
629 | int scan_lru_pages(unsigned long start, unsigned long end) | |
630 | { | |
631 | unsigned long pfn; | |
632 | struct page *page; | |
633 | for (pfn = start; pfn < end; pfn++) { | |
634 | if (pfn_valid(pfn)) { | |
635 | page = pfn_to_page(pfn); | |
636 | if (PageLRU(page)) | |
637 | return pfn; | |
638 | } | |
639 | } | |
640 | return 0; | |
641 | } | |
642 | ||
643 | static struct page * | |
3c1d4378 | 644 | hotremove_migrate_alloc(struct page *page, unsigned long private, int **x) |
0c0e6195 | 645 | { |
3c1d4378 HD |
646 | /* This should be improooooved!! */ |
647 | return alloc_page(GFP_HIGHUSER_MOVABLE); | |
0c0e6195 KH |
648 | } |
649 | ||
0c0e6195 KH |
650 | #define NR_OFFLINE_AT_ONCE_PAGES (256) |
651 | static int | |
652 | do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) | |
653 | { | |
654 | unsigned long pfn; | |
655 | struct page *page; | |
656 | int move_pages = NR_OFFLINE_AT_ONCE_PAGES; | |
657 | int not_managed = 0; | |
658 | int ret = 0; | |
659 | LIST_HEAD(source); | |
660 | ||
661 | for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) { | |
662 | if (!pfn_valid(pfn)) | |
663 | continue; | |
664 | page = pfn_to_page(pfn); | |
665 | if (!page_count(page)) | |
666 | continue; | |
667 | /* | |
668 | * We can skip free pages. And we can only deal with pages on | |
669 | * LRU. | |
670 | */ | |
62695a84 | 671 | ret = isolate_lru_page(page); |
0c0e6195 | 672 | if (!ret) { /* Success */ |
62695a84 | 673 | list_add_tail(&page->lru, &source); |
0c0e6195 KH |
674 | move_pages--; |
675 | } else { | |
676 | /* Becasue we don't have big zone->lock. we should | |
677 | check this again here. */ | |
678 | if (page_count(page)) | |
679 | not_managed++; | |
680 | #ifdef CONFIG_DEBUG_VM | |
681 | printk(KERN_INFO "removing from LRU failed" | |
682 | " %lx/%d/%lx\n", | |
683 | pfn, page_count(page), page->flags); | |
684 | #endif | |
685 | } | |
686 | } | |
687 | ret = -EBUSY; | |
688 | if (not_managed) { | |
689 | if (!list_empty(&source)) | |
690 | putback_lru_pages(&source); | |
691 | goto out; | |
692 | } | |
693 | ret = 0; | |
694 | if (list_empty(&source)) | |
695 | goto out; | |
696 | /* this function returns # of failed pages */ | |
697 | ret = migrate_pages(&source, hotremove_migrate_alloc, 0); | |
698 | ||
699 | out: | |
700 | return ret; | |
701 | } | |
702 | ||
703 | /* | |
704 | * remove from free_area[] and mark all as Reserved. | |
705 | */ | |
706 | static int | |
707 | offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages, | |
708 | void *data) | |
709 | { | |
710 | __offline_isolated_pages(start, start + nr_pages); | |
711 | return 0; | |
712 | } | |
713 | ||
714 | static void | |
715 | offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) | |
716 | { | |
908eedc6 | 717 | walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL, |
0c0e6195 KH |
718 | offline_isolated_pages_cb); |
719 | } | |
720 | ||
721 | /* | |
722 | * Check all pages in range, recoreded as memory resource, are isolated. | |
723 | */ | |
724 | static int | |
725 | check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages, | |
726 | void *data) | |
727 | { | |
728 | int ret; | |
729 | long offlined = *(long *)data; | |
730 | ret = test_pages_isolated(start_pfn, start_pfn + nr_pages); | |
731 | offlined = nr_pages; | |
732 | if (!ret) | |
733 | *(long *)data += offlined; | |
734 | return ret; | |
735 | } | |
736 | ||
737 | static long | |
738 | check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn) | |
739 | { | |
740 | long offlined = 0; | |
741 | int ret; | |
742 | ||
908eedc6 | 743 | ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined, |
0c0e6195 KH |
744 | check_pages_isolated_cb); |
745 | if (ret < 0) | |
746 | offlined = (long)ret; | |
747 | return offlined; | |
748 | } | |
749 | ||
0c0e6195 KH |
750 | int offline_pages(unsigned long start_pfn, |
751 | unsigned long end_pfn, unsigned long timeout) | |
752 | { | |
753 | unsigned long pfn, nr_pages, expire; | |
754 | long offlined_pages; | |
7b78d335 | 755 | int ret, drain, retry_max, node; |
0c0e6195 | 756 | struct zone *zone; |
7b78d335 | 757 | struct memory_notify arg; |
0c0e6195 KH |
758 | |
759 | BUG_ON(start_pfn >= end_pfn); | |
760 | /* at least, alignment against pageblock is necessary */ | |
761 | if (!IS_ALIGNED(start_pfn, pageblock_nr_pages)) | |
762 | return -EINVAL; | |
763 | if (!IS_ALIGNED(end_pfn, pageblock_nr_pages)) | |
764 | return -EINVAL; | |
765 | /* This makes hotplug much easier...and readable. | |
766 | we assume this for now. .*/ | |
767 | if (!test_pages_in_a_zone(start_pfn, end_pfn)) | |
768 | return -EINVAL; | |
7b78d335 | 769 | |
6ad696d2 AK |
770 | lock_system_sleep(); |
771 | ||
7b78d335 YG |
772 | zone = page_zone(pfn_to_page(start_pfn)); |
773 | node = zone_to_nid(zone); | |
774 | nr_pages = end_pfn - start_pfn; | |
775 | ||
0c0e6195 KH |
776 | /* set above range as isolated */ |
777 | ret = start_isolate_page_range(start_pfn, end_pfn); | |
778 | if (ret) | |
6ad696d2 | 779 | goto out; |
7b78d335 YG |
780 | |
781 | arg.start_pfn = start_pfn; | |
782 | arg.nr_pages = nr_pages; | |
783 | arg.status_change_nid = -1; | |
784 | if (nr_pages >= node_present_pages(node)) | |
785 | arg.status_change_nid = node; | |
786 | ||
787 | ret = memory_notify(MEM_GOING_OFFLINE, &arg); | |
788 | ret = notifier_to_errno(ret); | |
789 | if (ret) | |
790 | goto failed_removal; | |
791 | ||
0c0e6195 KH |
792 | pfn = start_pfn; |
793 | expire = jiffies + timeout; | |
794 | drain = 0; | |
795 | retry_max = 5; | |
796 | repeat: | |
797 | /* start memory hot removal */ | |
798 | ret = -EAGAIN; | |
799 | if (time_after(jiffies, expire)) | |
800 | goto failed_removal; | |
801 | ret = -EINTR; | |
802 | if (signal_pending(current)) | |
803 | goto failed_removal; | |
804 | ret = 0; | |
805 | if (drain) { | |
806 | lru_add_drain_all(); | |
807 | flush_scheduled_work(); | |
808 | cond_resched(); | |
9f8f2172 | 809 | drain_all_pages(); |
0c0e6195 KH |
810 | } |
811 | ||
812 | pfn = scan_lru_pages(start_pfn, end_pfn); | |
813 | if (pfn) { /* We have page on LRU */ | |
814 | ret = do_migrate_range(pfn, end_pfn); | |
815 | if (!ret) { | |
816 | drain = 1; | |
817 | goto repeat; | |
818 | } else { | |
819 | if (ret < 0) | |
820 | if (--retry_max == 0) | |
821 | goto failed_removal; | |
822 | yield(); | |
823 | drain = 1; | |
824 | goto repeat; | |
825 | } | |
826 | } | |
827 | /* drain all zone's lru pagevec, this is asyncronous... */ | |
828 | lru_add_drain_all(); | |
829 | flush_scheduled_work(); | |
830 | yield(); | |
831 | /* drain pcp pages , this is synchrouns. */ | |
9f8f2172 | 832 | drain_all_pages(); |
0c0e6195 KH |
833 | /* check again */ |
834 | offlined_pages = check_pages_isolated(start_pfn, end_pfn); | |
835 | if (offlined_pages < 0) { | |
836 | ret = -EBUSY; | |
837 | goto failed_removal; | |
838 | } | |
839 | printk(KERN_INFO "Offlined Pages %ld\n", offlined_pages); | |
840 | /* Ok, all of our target is islaoted. | |
841 | We cannot do rollback at this point. */ | |
842 | offline_isolated_pages(start_pfn, end_pfn); | |
dbc0e4ce KH |
843 | /* reset pagetype flags and makes migrate type to be MOVABLE */ |
844 | undo_isolate_page_range(start_pfn, end_pfn); | |
0c0e6195 | 845 | /* removal success */ |
0c0e6195 KH |
846 | zone->present_pages -= offlined_pages; |
847 | zone->zone_pgdat->node_present_pages -= offlined_pages; | |
848 | totalram_pages -= offlined_pages; | |
7b78d335 | 849 | |
bce7394a MK |
850 | setup_per_zone_wmarks(); |
851 | calculate_zone_inactive_ratio(zone); | |
852 | ||
0c0e6195 KH |
853 | vm_total_pages = nr_free_pagecache_pages(); |
854 | writeback_set_ratelimit(); | |
7b78d335 YG |
855 | |
856 | memory_notify(MEM_OFFLINE, &arg); | |
6ad696d2 | 857 | unlock_system_sleep(); |
0c0e6195 KH |
858 | return 0; |
859 | ||
860 | failed_removal: | |
861 | printk(KERN_INFO "memory offlining %lx to %lx failed\n", | |
862 | start_pfn, end_pfn); | |
7b78d335 | 863 | memory_notify(MEM_CANCEL_OFFLINE, &arg); |
0c0e6195 KH |
864 | /* pushback to free area */ |
865 | undo_isolate_page_range(start_pfn, end_pfn); | |
7b78d335 | 866 | |
6ad696d2 AK |
867 | out: |
868 | unlock_system_sleep(); | |
0c0e6195 KH |
869 | return ret; |
870 | } | |
71088785 BP |
871 | |
872 | int remove_memory(u64 start, u64 size) | |
873 | { | |
874 | unsigned long start_pfn, end_pfn; | |
875 | ||
876 | start_pfn = PFN_DOWN(start); | |
877 | end_pfn = start_pfn + PFN_DOWN(size); | |
878 | return offline_pages(start_pfn, end_pfn, 120 * HZ); | |
879 | } | |
48e94196 KH |
880 | #else |
881 | int remove_memory(u64 start, u64 size) | |
882 | { | |
883 | return -EINVAL; | |
884 | } | |
0c0e6195 | 885 | #endif /* CONFIG_MEMORY_HOTREMOVE */ |
71088785 | 886 | EXPORT_SYMBOL_GPL(remove_memory); |