blob: 0fb33027127120460a05ddc2bb827d7b26d31aaa [file] [log] [blame]
Dave Hansen3947be12005-10-29 18:16:54 -07001/*
2 * linux/mm/memory_hotplug.c
3 *
4 * Copyright (C)
5 */
6
Dave Hansen3947be12005-10-29 18:16:54 -07007#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>
Chandra Seetharaman2d1d43f2006-09-29 02:01:25 -070016#include <linux/writeback.h>
Dave Hansen3947be12005-10-29 18:16:54 -070017#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>
KAMEZAWA Hiroyuki0a547032006-06-27 02:53:35 -070024#include <linux/ioport.h>
Paul Jackson38837fc2006-09-29 02:01:16 -070025#include <linux/cpuset.h>
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -070026#include <linux/delay.h>
27#include <linux/migrate.h>
28#include <linux/page-isolation.h>
Dave Hansen3947be12005-10-29 18:16:54 -070029
30#include <asm/tlbflush.h>
31
Keith Mannthey45e0b782006-09-30 23:27:09 -070032/* add this memory to iomem resource */
33static 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;
Yasunori Goto887c3cb2007-11-14 16:59:20 -080042 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
Keith Mannthey45e0b782006-09-30 23:27:09 -070043 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
52static 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
Keith Mannthey53947022006-09-30 23:27:08 -070062#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
Yasunori Goto718127c2006-06-23 02:03:10 -070063static int __add_zone(struct zone *zone, unsigned long phys_start_pfn)
Dave Hansen3947be12005-10-29 18:16:54 -070064{
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;
Yasunori Goto13466c82007-06-01 00:46:53 -070071 if (!zone->wait_table) {
Yasunori Goto718127c2006-06-23 02:03:10 -070072 int ret = 0;
Dave Hansena2f3aa022007-01-10 23:15:30 -080073 ret = init_currently_empty_zone(zone, phys_start_pfn,
74 nr_pages, MEMMAP_HOTPLUG);
Yasunori Goto718127c2006-06-23 02:03:10 -070075 if (ret < 0)
76 return ret;
77 }
Dave Hansena2f3aa022007-01-10 23:15:30 -080078 memmap_init_zone(nr_pages, nid, zone_type,
79 phys_start_pfn, MEMMAP_HOTPLUG);
Yasunori Goto718127c2006-06-23 02:03:10 -070080 return 0;
Dave Hansen3947be12005-10-29 18:16:54 -070081}
82
Dave Hansen3947be12005-10-29 18:16:54 -070083static int __add_section(struct zone *zone, unsigned long phys_start_pfn)
84{
Dave Hansen3947be12005-10-29 18:16:54 -070085 int nr_pages = PAGES_PER_SECTION;
Dave Hansen3947be12005-10-29 18:16:54 -070086 int ret;
87
KAMEZAWA Hiroyukiebd15302006-08-05 12:15:06 -070088 if (pfn_valid(phys_start_pfn))
89 return -EEXIST;
90
Dave Hansen0b0acbe2005-10-29 18:16:55 -070091 ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
Dave Hansen3947be12005-10-29 18:16:54 -070092
93 if (ret < 0)
94 return ret;
95
Yasunori Goto718127c2006-06-23 02:03:10 -070096 ret = __add_zone(zone, phys_start_pfn);
97
98 if (ret < 0)
99 return ret;
100
Dave Hansen3947be12005-10-29 18:16:54 -0700101 return register_new_memory(__pfn_to_section(phys_start_pfn));
102}
103
104/*
105 * Reasonably generic function for adding memory. It is
106 * expected that archs that support memory hotplug will
107 * call this function after deciding the zone to which to
108 * add the new pages.
109 */
110int __add_pages(struct zone *zone, unsigned long phys_start_pfn,
111 unsigned long nr_pages)
112{
113 unsigned long i;
114 int err = 0;
KAMEZAWA Hiroyuki6f712712006-08-05 12:14:58 -0700115 int start_sec, end_sec;
116 /* during initialize mem_map, align hot-added range to section */
117 start_sec = pfn_to_section_nr(phys_start_pfn);
118 end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
Dave Hansen3947be12005-10-29 18:16:54 -0700119
KAMEZAWA Hiroyuki6f712712006-08-05 12:14:58 -0700120 for (i = start_sec; i <= end_sec; i++) {
121 err = __add_section(zone, i << PFN_SECTION_SHIFT);
Dave Hansen3947be12005-10-29 18:16:54 -0700122
KAMEZAWA Hiroyuki6f712712006-08-05 12:14:58 -0700123 /*
Simon Arlott183ff222007-10-20 01:27:18 +0200124 * EEXIST is finally dealt with by ioresource collision
KAMEZAWA Hiroyuki6f712712006-08-05 12:14:58 -0700125 * check. see add_memory() => register_memory_resource()
126 * Warning will be printed if there is collision.
Joel H Schoppbed120c2006-05-01 12:16:11 -0700127 */
128 if (err && (err != -EEXIST))
Dave Hansen3947be12005-10-29 18:16:54 -0700129 break;
KAMEZAWA Hiroyuki6f712712006-08-05 12:14:58 -0700130 err = 0;
Dave Hansen3947be12005-10-29 18:16:54 -0700131 }
132
133 return err;
134}
Joel H Schoppbed120c2006-05-01 12:16:11 -0700135EXPORT_SYMBOL_GPL(__add_pages);
Dave Hansen3947be12005-10-29 18:16:54 -0700136
137static void grow_zone_span(struct zone *zone,
138 unsigned long start_pfn, unsigned long end_pfn)
139{
140 unsigned long old_zone_end_pfn;
141
142 zone_span_writelock(zone);
143
144 old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
145 if (start_pfn < zone->zone_start_pfn)
146 zone->zone_start_pfn = start_pfn;
147
Yasunori Goto25a6df92006-05-30 21:25:42 -0700148 zone->spanned_pages = max(old_zone_end_pfn, end_pfn) -
149 zone->zone_start_pfn;
Dave Hansen3947be12005-10-29 18:16:54 -0700150
151 zone_span_writeunlock(zone);
152}
153
154static void grow_pgdat_span(struct pglist_data *pgdat,
155 unsigned long start_pfn, unsigned long end_pfn)
156{
157 unsigned long old_pgdat_end_pfn =
158 pgdat->node_start_pfn + pgdat->node_spanned_pages;
159
160 if (start_pfn < pgdat->node_start_pfn)
161 pgdat->node_start_pfn = start_pfn;
162
Yasunori Goto25a6df92006-05-30 21:25:42 -0700163 pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) -
164 pgdat->node_start_pfn;
Dave Hansen3947be12005-10-29 18:16:54 -0700165}
166
KAMEZAWA Hiroyuki75884fb2007-10-16 01:26:10 -0700167static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
168 void *arg)
Dave Hansen3947be12005-10-29 18:16:54 -0700169{
170 unsigned long i;
KAMEZAWA Hiroyuki75884fb2007-10-16 01:26:10 -0700171 unsigned long onlined_pages = *(unsigned long *)arg;
172 struct page *page;
173 if (PageReserved(pfn_to_page(start_pfn)))
174 for (i = 0; i < nr_pages; i++) {
175 page = pfn_to_page(start_pfn + i);
176 online_page(page);
177 onlined_pages++;
178 }
179 *(unsigned long *)arg = onlined_pages;
180 return 0;
181}
182
183
184int online_pages(unsigned long pfn, unsigned long nr_pages)
185{
Dave Hansen3947be12005-10-29 18:16:54 -0700186 unsigned long flags;
187 unsigned long onlined_pages = 0;
188 struct zone *zone;
Yasunori Goto68113782006-06-23 02:03:11 -0700189 int need_zonelists_rebuild = 0;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700190 int nid;
191 int ret;
192 struct memory_notify arg;
Dave Hansen3947be12005-10-29 18:16:54 -0700193
Yasunori Goto7b78d332007-10-21 16:41:36 -0700194 arg.start_pfn = pfn;
195 arg.nr_pages = nr_pages;
196 arg.status_change_nid = -1;
197
198 nid = page_to_nid(pfn_to_page(pfn));
199 if (node_present_pages(nid) == 0)
200 arg.status_change_nid = nid;
201
202 ret = memory_notify(MEM_GOING_ONLINE, &arg);
203 ret = notifier_to_errno(ret);
204 if (ret) {
205 memory_notify(MEM_CANCEL_ONLINE, &arg);
206 return ret;
207 }
Dave Hansen3947be12005-10-29 18:16:54 -0700208 /*
209 * This doesn't need a lock to do pfn_to_page().
210 * The section can't be removed here because of the
Daniel Walkerda19cbc2008-02-04 23:35:47 -0800211 * memory_block->state_mutex.
Dave Hansen3947be12005-10-29 18:16:54 -0700212 */
213 zone = page_zone(pfn_to_page(pfn));
214 pgdat_resize_lock(zone->zone_pgdat, &flags);
215 grow_zone_span(zone, pfn, pfn + nr_pages);
216 grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages);
217 pgdat_resize_unlock(zone->zone_pgdat, &flags);
218
Yasunori Goto68113782006-06-23 02:03:11 -0700219 /*
220 * If this zone is not populated, then it is not in zonelist.
221 * This means the page allocator ignores this zone.
222 * So, zonelist must be updated after online.
223 */
224 if (!populated_zone(zone))
225 need_zonelists_rebuild = 1;
226
KAMEZAWA Hiroyuki75884fb2007-10-16 01:26:10 -0700227 walk_memory_resource(pfn, nr_pages, &onlined_pages,
228 online_pages_range);
Dave Hansen3947be12005-10-29 18:16:54 -0700229 zone->present_pages += onlined_pages;
Yasunori Gotof2937be2006-03-09 17:33:51 -0800230 zone->zone_pgdat->node_present_pages += onlined_pages;
Dave Hansen3947be12005-10-29 18:16:54 -0700231
Dave Hansen61b13992005-10-29 18:16:56 -0700232 setup_per_zone_pages_min();
Christoph Lameter7ea15302007-10-16 01:25:29 -0700233 if (onlined_pages) {
234 kswapd_run(zone_to_nid(zone));
235 node_set_state(zone_to_nid(zone), N_HIGH_MEMORY);
236 }
Dave Hansen61b13992005-10-29 18:16:56 -0700237
Yasunori Goto68113782006-06-23 02:03:11 -0700238 if (need_zonelists_rebuild)
239 build_all_zonelists();
KAMEZAWA Hiroyuki5a4d4362006-06-23 02:03:47 -0700240 vm_total_pages = nr_free_pagecache_pages();
Chandra Seetharaman2d1d43f2006-09-29 02:01:25 -0700241 writeback_set_ratelimit();
Yasunori Goto7b78d332007-10-21 16:41:36 -0700242
243 if (onlined_pages)
244 memory_notify(MEM_ONLINE, &arg);
245
Dave Hansen3947be12005-10-29 18:16:54 -0700246 return 0;
247}
Keith Mannthey53947022006-09-30 23:27:08 -0700248#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
Yasunori Gotobc02af92006-06-27 02:53:30 -0700249
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700250static pg_data_t *hotadd_new_pgdat(int nid, u64 start)
251{
252 struct pglist_data *pgdat;
253 unsigned long zones_size[MAX_NR_ZONES] = {0};
254 unsigned long zholes_size[MAX_NR_ZONES] = {0};
255 unsigned long start_pfn = start >> PAGE_SHIFT;
256
257 pgdat = arch_alloc_nodedata(nid);
258 if (!pgdat)
259 return NULL;
260
261 arch_refresh_nodedata(nid, pgdat);
262
263 /* we can use NODE_DATA(nid) from here */
264
265 /* init node's zones as empty zones, we don't have any present pages.*/
266 free_area_init_node(nid, pgdat, zones_size, start_pfn, zholes_size);
267
268 return pgdat;
269}
270
271static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
272{
273 arch_refresh_nodedata(nid, NULL);
274 arch_free_nodedata(pgdat);
275 return;
276}
277
KAMEZAWA Hiroyuki0a547032006-06-27 02:53:35 -0700278
Yasunori Gotobc02af92006-06-27 02:53:30 -0700279int add_memory(int nid, u64 start, u64 size)
280{
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700281 pg_data_t *pgdat = NULL;
282 int new_pgdat = 0;
KAMEZAWA Hiroyukiebd15302006-08-05 12:15:06 -0700283 struct resource *res;
Yasunori Gotobc02af92006-06-27 02:53:30 -0700284 int ret;
285
KAMEZAWA Hiroyukiebd15302006-08-05 12:15:06 -0700286 res = register_memory_resource(start, size);
287 if (!res)
288 return -EEXIST;
289
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700290 if (!node_online(nid)) {
291 pgdat = hotadd_new_pgdat(nid, start);
292 if (!pgdat)
293 return -ENOMEM;
294 new_pgdat = 1;
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700295 }
296
Yasunori Gotobc02af92006-06-27 02:53:30 -0700297 /* call arch's memory hotadd */
298 ret = arch_add_memory(nid, start, size);
299
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700300 if (ret < 0)
301 goto error;
302
Yasunori Goto0fc44152006-06-27 02:53:38 -0700303 /* we online node here. we can't roll back from here. */
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700304 node_set_online(nid);
305
Paul Jackson38837fc2006-09-29 02:01:16 -0700306 cpuset_track_online_nodes();
307
Yasunori Goto0fc44152006-06-27 02:53:38 -0700308 if (new_pgdat) {
309 ret = register_one_node(nid);
310 /*
311 * If sysfs file of new node can't create, cpu on the node
312 * can't be hot-added. There is no rollback way now.
313 * So, check by BUG_ON() to catch it reluctantly..
314 */
315 BUG_ON(ret);
316 }
317
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700318 return ret;
319error:
320 /* rollback pgdat allocation and others */
321 if (new_pgdat)
322 rollback_node_hotadd(nid, pgdat);
KAMEZAWA Hiroyukiebd15302006-08-05 12:15:06 -0700323 if (res)
324 release_memory_resource(res);
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700325
Yasunori Gotobc02af92006-06-27 02:53:30 -0700326 return ret;
327}
328EXPORT_SYMBOL_GPL(add_memory);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700329
330#ifdef CONFIG_MEMORY_HOTREMOVE
331/*
332 * Confirm all pages in a range [start, end) is belongs to the same zone.
333 */
334static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn)
335{
336 unsigned long pfn;
337 struct zone *zone = NULL;
338 struct page *page;
339 int i;
340 for (pfn = start_pfn;
341 pfn < end_pfn;
342 pfn += MAX_ORDER_NR_PAGES) {
343 i = 0;
344 /* This is just a CONFIG_HOLES_IN_ZONE check.*/
345 while ((i < MAX_ORDER_NR_PAGES) && !pfn_valid_within(pfn + i))
346 i++;
347 if (i == MAX_ORDER_NR_PAGES)
348 continue;
349 page = pfn_to_page(pfn + i);
350 if (zone && page_zone(page) != zone)
351 return 0;
352 zone = page_zone(page);
353 }
354 return 1;
355}
356
357/*
358 * Scanning pfn is much easier than scanning lru list.
359 * Scan pfn from start to end and Find LRU page.
360 */
361int scan_lru_pages(unsigned long start, unsigned long end)
362{
363 unsigned long pfn;
364 struct page *page;
365 for (pfn = start; pfn < end; pfn++) {
366 if (pfn_valid(pfn)) {
367 page = pfn_to_page(pfn);
368 if (PageLRU(page))
369 return pfn;
370 }
371 }
372 return 0;
373}
374
375static struct page *
376hotremove_migrate_alloc(struct page *page,
377 unsigned long private,
378 int **x)
379{
380 /* This should be improoooooved!! */
381 return alloc_page(GFP_HIGHUSER_PAGECACHE);
382}
383
384
385#define NR_OFFLINE_AT_ONCE_PAGES (256)
386static int
387do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
388{
389 unsigned long pfn;
390 struct page *page;
391 int move_pages = NR_OFFLINE_AT_ONCE_PAGES;
392 int not_managed = 0;
393 int ret = 0;
394 LIST_HEAD(source);
395
396 for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) {
397 if (!pfn_valid(pfn))
398 continue;
399 page = pfn_to_page(pfn);
400 if (!page_count(page))
401 continue;
402 /*
403 * We can skip free pages. And we can only deal with pages on
404 * LRU.
405 */
406 ret = isolate_lru_page(page, &source);
407 if (!ret) { /* Success */
408 move_pages--;
409 } else {
410 /* Becasue we don't have big zone->lock. we should
411 check this again here. */
412 if (page_count(page))
413 not_managed++;
414#ifdef CONFIG_DEBUG_VM
415 printk(KERN_INFO "removing from LRU failed"
416 " %lx/%d/%lx\n",
417 pfn, page_count(page), page->flags);
418#endif
419 }
420 }
421 ret = -EBUSY;
422 if (not_managed) {
423 if (!list_empty(&source))
424 putback_lru_pages(&source);
425 goto out;
426 }
427 ret = 0;
428 if (list_empty(&source))
429 goto out;
430 /* this function returns # of failed pages */
431 ret = migrate_pages(&source, hotremove_migrate_alloc, 0);
432
433out:
434 return ret;
435}
436
437/*
438 * remove from free_area[] and mark all as Reserved.
439 */
440static int
441offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
442 void *data)
443{
444 __offline_isolated_pages(start, start + nr_pages);
445 return 0;
446}
447
448static void
449offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
450{
451 walk_memory_resource(start_pfn, end_pfn - start_pfn, NULL,
452 offline_isolated_pages_cb);
453}
454
455/*
456 * Check all pages in range, recoreded as memory resource, are isolated.
457 */
458static int
459check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
460 void *data)
461{
462 int ret;
463 long offlined = *(long *)data;
464 ret = test_pages_isolated(start_pfn, start_pfn + nr_pages);
465 offlined = nr_pages;
466 if (!ret)
467 *(long *)data += offlined;
468 return ret;
469}
470
471static long
472check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
473{
474 long offlined = 0;
475 int ret;
476
477 ret = walk_memory_resource(start_pfn, end_pfn - start_pfn, &offlined,
478 check_pages_isolated_cb);
479 if (ret < 0)
480 offlined = (long)ret;
481 return offlined;
482}
483
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700484int offline_pages(unsigned long start_pfn,
485 unsigned long end_pfn, unsigned long timeout)
486{
487 unsigned long pfn, nr_pages, expire;
488 long offlined_pages;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700489 int ret, drain, retry_max, node;
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700490 struct zone *zone;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700491 struct memory_notify arg;
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700492
493 BUG_ON(start_pfn >= end_pfn);
494 /* at least, alignment against pageblock is necessary */
495 if (!IS_ALIGNED(start_pfn, pageblock_nr_pages))
496 return -EINVAL;
497 if (!IS_ALIGNED(end_pfn, pageblock_nr_pages))
498 return -EINVAL;
499 /* This makes hotplug much easier...and readable.
500 we assume this for now. .*/
501 if (!test_pages_in_a_zone(start_pfn, end_pfn))
502 return -EINVAL;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700503
504 zone = page_zone(pfn_to_page(start_pfn));
505 node = zone_to_nid(zone);
506 nr_pages = end_pfn - start_pfn;
507
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700508 /* set above range as isolated */
509 ret = start_isolate_page_range(start_pfn, end_pfn);
510 if (ret)
511 return ret;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700512
513 arg.start_pfn = start_pfn;
514 arg.nr_pages = nr_pages;
515 arg.status_change_nid = -1;
516 if (nr_pages >= node_present_pages(node))
517 arg.status_change_nid = node;
518
519 ret = memory_notify(MEM_GOING_OFFLINE, &arg);
520 ret = notifier_to_errno(ret);
521 if (ret)
522 goto failed_removal;
523
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700524 pfn = start_pfn;
525 expire = jiffies + timeout;
526 drain = 0;
527 retry_max = 5;
528repeat:
529 /* start memory hot removal */
530 ret = -EAGAIN;
531 if (time_after(jiffies, expire))
532 goto failed_removal;
533 ret = -EINTR;
534 if (signal_pending(current))
535 goto failed_removal;
536 ret = 0;
537 if (drain) {
538 lru_add_drain_all();
539 flush_scheduled_work();
540 cond_resched();
Christoph Lameter9f8f2172008-02-04 22:29:11 -0800541 drain_all_pages();
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700542 }
543
544 pfn = scan_lru_pages(start_pfn, end_pfn);
545 if (pfn) { /* We have page on LRU */
546 ret = do_migrate_range(pfn, end_pfn);
547 if (!ret) {
548 drain = 1;
549 goto repeat;
550 } else {
551 if (ret < 0)
552 if (--retry_max == 0)
553 goto failed_removal;
554 yield();
555 drain = 1;
556 goto repeat;
557 }
558 }
559 /* drain all zone's lru pagevec, this is asyncronous... */
560 lru_add_drain_all();
561 flush_scheduled_work();
562 yield();
563 /* drain pcp pages , this is synchrouns. */
Christoph Lameter9f8f2172008-02-04 22:29:11 -0800564 drain_all_pages();
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700565 /* check again */
566 offlined_pages = check_pages_isolated(start_pfn, end_pfn);
567 if (offlined_pages < 0) {
568 ret = -EBUSY;
569 goto failed_removal;
570 }
571 printk(KERN_INFO "Offlined Pages %ld\n", offlined_pages);
572 /* Ok, all of our target is islaoted.
573 We cannot do rollback at this point. */
574 offline_isolated_pages(start_pfn, end_pfn);
KAMEZAWA Hiroyukidbc0e4c2007-11-14 16:59:12 -0800575 /* reset pagetype flags and makes migrate type to be MOVABLE */
576 undo_isolate_page_range(start_pfn, end_pfn);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700577 /* removal success */
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700578 zone->present_pages -= offlined_pages;
579 zone->zone_pgdat->node_present_pages -= offlined_pages;
580 totalram_pages -= offlined_pages;
581 num_physpages -= offlined_pages;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700582
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700583 vm_total_pages = nr_free_pagecache_pages();
584 writeback_set_ratelimit();
Yasunori Goto7b78d332007-10-21 16:41:36 -0700585
586 memory_notify(MEM_OFFLINE, &arg);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700587 return 0;
588
589failed_removal:
590 printk(KERN_INFO "memory offlining %lx to %lx failed\n",
591 start_pfn, end_pfn);
Yasunori Goto7b78d332007-10-21 16:41:36 -0700592 memory_notify(MEM_CANCEL_OFFLINE, &arg);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700593 /* pushback to free area */
594 undo_isolate_page_range(start_pfn, end_pfn);
Yasunori Goto7b78d332007-10-21 16:41:36 -0700595
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700596 return ret;
597}
KAMEZAWA Hiroyuki48e94192007-10-16 01:26:14 -0700598#else
599int remove_memory(u64 start, u64 size)
600{
601 return -EINVAL;
602}
603EXPORT_SYMBOL_GPL(remove_memory);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700604#endif /* CONFIG_MEMORY_HOTREMOVE */