blob: 6837a1014372556c7dd78d66d9ba9ea9cb931832 [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>
Badari Pulavarty71088782008-10-18 20:25:58 -070029#include <linux/pfn.h>
Dave Hansen3947be12005-10-29 18:16:54 -070030
31#include <asm/tlbflush.h>
32
Adrian Bunk1e5ad9a2008-04-28 20:40:08 +030033#include "internal.h"
34
Keith Mannthey45e0b782006-09-30 23:27:09 -070035/* add this memory to iomem resource */
36static 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;
Yasunori Goto887c3cb2007-11-14 16:59:20 -080045 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
Keith Mannthey45e0b782006-09-30 23:27:09 -070046 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
55static void release_memory_resource(struct resource *res)
56{
57 if (!res)
58 return;
59 release_resource(res);
60 kfree(res);
61 return;
62}
63
Keith Mannthey53947022006-09-30 23:27:08 -070064#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
Yasunori Goto04753272008-04-28 02:13:31 -070065#ifndef CONFIG_SPARSEMEM_VMEMMAP
Yasunori Gotoaf370fb2008-07-23 21:28:17 -070066static void get_page_bootmem(unsigned long info, struct page *page, int type)
Yasunori Goto04753272008-04-28 02:13:31 -070067{
Yasunori Gotoaf370fb2008-07-23 21:28:17 -070068 atomic_set(&page->_mapcount, type);
Yasunori Goto04753272008-04-28 02:13:31 -070069 SetPagePrivate(page);
70 set_page_private(page, info);
71 atomic_inc(&page->_count);
72}
73
74void put_page_bootmem(struct page *page)
75{
Yasunori Gotoaf370fb2008-07-23 21:28:17 -070076 int type;
Yasunori Goto04753272008-04-28 02:13:31 -070077
Yasunori Gotoaf370fb2008-07-23 21:28:17 -070078 type = atomic_read(&page->_mapcount);
79 BUG_ON(type >= -1);
Yasunori Goto04753272008-04-28 02:13:31 -070080
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
Adrian Bunkd92bc312008-07-23 21:28:12 -070090static void register_page_bootmem_info_section(unsigned long start_pfn)
Yasunori Goto04753272008-04-28 02:13:31 -070091{
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++)
Yasunori Gotoaf370fb2008-07-23 21:28:17 -0700123 get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
Yasunori Goto04753272008-04-28 02:13:31 -0700124
125}
126
127void 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
Heiko Carstens76cdd582008-05-14 16:05:52 -0700163static 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
180static 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
Yasunori Goto718127c2006-06-23 02:03:10 -0700193static int __add_zone(struct zone *zone, unsigned long phys_start_pfn)
Dave Hansen3947be12005-10-29 18:16:54 -0700194{
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;
Heiko Carstens76cdd582008-05-14 16:05:52 -0700199 unsigned long flags;
Dave Hansen3947be12005-10-29 18:16:54 -0700200
201 zone_type = zone - pgdat->node_zones;
Heiko Carstens76cdd582008-05-14 16:05:52 -0700202 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);
Dave Hansena2f3aa022007-01-10 23:15:30 -0800215 memmap_init_zone(nr_pages, nid, zone_type,
216 phys_start_pfn, MEMMAP_HOTPLUG);
Yasunori Goto718127c2006-06-23 02:03:10 -0700217 return 0;
Dave Hansen3947be12005-10-29 18:16:54 -0700218}
219
Dave Hansen3947be12005-10-29 18:16:54 -0700220static int __add_section(struct zone *zone, unsigned long phys_start_pfn)
221{
Dave Hansen3947be12005-10-29 18:16:54 -0700222 int nr_pages = PAGES_PER_SECTION;
Dave Hansen3947be12005-10-29 18:16:54 -0700223 int ret;
224
KAMEZAWA Hiroyukiebd15302006-08-05 12:15:06 -0700225 if (pfn_valid(phys_start_pfn))
226 return -EEXIST;
227
Dave Hansen0b0acbe2005-10-29 18:16:55 -0700228 ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
Dave Hansen3947be12005-10-29 18:16:54 -0700229
230 if (ret < 0)
231 return ret;
232
Yasunori Goto718127c2006-06-23 02:03:10 -0700233 ret = __add_zone(zone, phys_start_pfn);
234
235 if (ret < 0)
236 return ret;
237
Dave Hansen3947be12005-10-29 18:16:54 -0700238 return register_new_memory(__pfn_to_section(phys_start_pfn));
239}
240
Yasunori Goto0c0a4a52008-04-28 02:13:34 -0700241#ifdef CONFIG_SPARSEMEM_VMEMMAP
242static int __remove_section(struct zone *zone, struct mem_section *ms)
243{
244 /*
245 * XXX: Freeing memmap with vmemmap is not implement yet.
246 * This should be removed later.
247 */
248 return -EBUSY;
249}
250#else
Badari Pulavartyea01ea92008-04-28 02:12:01 -0700251static int __remove_section(struct zone *zone, struct mem_section *ms)
252{
253 unsigned long flags;
254 struct pglist_data *pgdat = zone->zone_pgdat;
255 int ret = -EINVAL;
256
257 if (!valid_section(ms))
258 return ret;
259
260 ret = unregister_memory_section(ms);
261 if (ret)
262 return ret;
263
264 pgdat_resize_lock(pgdat, &flags);
265 sparse_remove_one_section(zone, ms);
266 pgdat_resize_unlock(pgdat, &flags);
267 return 0;
268}
Yasunori Goto0c0a4a52008-04-28 02:13:34 -0700269#endif
Badari Pulavartyea01ea92008-04-28 02:12:01 -0700270
Dave Hansen3947be12005-10-29 18:16:54 -0700271/*
272 * Reasonably generic function for adding memory. It is
273 * expected that archs that support memory hotplug will
274 * call this function after deciding the zone to which to
275 * add the new pages.
276 */
277int __add_pages(struct zone *zone, unsigned long phys_start_pfn,
278 unsigned long nr_pages)
279{
280 unsigned long i;
281 int err = 0;
KAMEZAWA Hiroyuki6f712712006-08-05 12:14:58 -0700282 int start_sec, end_sec;
283 /* during initialize mem_map, align hot-added range to section */
284 start_sec = pfn_to_section_nr(phys_start_pfn);
285 end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
Dave Hansen3947be12005-10-29 18:16:54 -0700286
KAMEZAWA Hiroyuki6f712712006-08-05 12:14:58 -0700287 for (i = start_sec; i <= end_sec; i++) {
288 err = __add_section(zone, i << PFN_SECTION_SHIFT);
Dave Hansen3947be12005-10-29 18:16:54 -0700289
KAMEZAWA Hiroyuki6f712712006-08-05 12:14:58 -0700290 /*
Simon Arlott183ff222007-10-20 01:27:18 +0200291 * EEXIST is finally dealt with by ioresource collision
KAMEZAWA Hiroyuki6f712712006-08-05 12:14:58 -0700292 * check. see add_memory() => register_memory_resource()
293 * Warning will be printed if there is collision.
Joel H Schoppbed120c2006-05-01 12:16:11 -0700294 */
295 if (err && (err != -EEXIST))
Dave Hansen3947be12005-10-29 18:16:54 -0700296 break;
KAMEZAWA Hiroyuki6f712712006-08-05 12:14:58 -0700297 err = 0;
Dave Hansen3947be12005-10-29 18:16:54 -0700298 }
299
300 return err;
301}
Joel H Schoppbed120c2006-05-01 12:16:11 -0700302EXPORT_SYMBOL_GPL(__add_pages);
Dave Hansen3947be12005-10-29 18:16:54 -0700303
Badari Pulavartyea01ea92008-04-28 02:12:01 -0700304/**
305 * __remove_pages() - remove sections of pages from a zone
306 * @zone: zone from which pages need to be removed
307 * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
308 * @nr_pages: number of pages to remove (must be multiple of section size)
309 *
310 * Generic helper function to remove section mappings and sysfs entries
311 * for the section of the memory we are removing. Caller needs to make
312 * sure that pages are marked reserved and zones are adjust properly by
313 * calling offline_pages().
314 */
315int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
316 unsigned long nr_pages)
317{
318 unsigned long i, ret = 0;
319 int sections_to_remove;
320
321 /*
322 * We can only remove entire sections
323 */
324 BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK);
325 BUG_ON(nr_pages % PAGES_PER_SECTION);
326
Badari Pulavartyea01ea92008-04-28 02:12:01 -0700327 sections_to_remove = nr_pages / PAGES_PER_SECTION;
328 for (i = 0; i < sections_to_remove; i++) {
329 unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
Nathan Fontenotde7f0cb2008-10-18 20:27:14 -0700330 release_mem_region(pfn << PAGE_SHIFT,
331 PAGES_PER_SECTION << PAGE_SHIFT);
Badari Pulavartyea01ea92008-04-28 02:12:01 -0700332 ret = __remove_section(zone, __pfn_to_section(pfn));
333 if (ret)
334 break;
335 }
336 return ret;
337}
338EXPORT_SYMBOL_GPL(__remove_pages);
339
Jeremy Fitzhardinge180c06e2008-04-28 02:12:03 -0700340void online_page(struct page *page)
341{
342 totalram_pages++;
343 num_physpages++;
344
345#ifdef CONFIG_HIGHMEM
346 if (PageHighMem(page))
347 totalhigh_pages++;
348#endif
349
350#ifdef CONFIG_FLATMEM
351 max_mapnr = max(page_to_pfn(page), max_mapnr);
352#endif
353
354 ClearPageReserved(page);
355 init_page_count(page);
356 __free_page(page);
357}
358
KAMEZAWA Hiroyuki75884fb2007-10-16 01:26:10 -0700359static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
360 void *arg)
Dave Hansen3947be12005-10-29 18:16:54 -0700361{
362 unsigned long i;
KAMEZAWA Hiroyuki75884fb2007-10-16 01:26:10 -0700363 unsigned long onlined_pages = *(unsigned long *)arg;
364 struct page *page;
365 if (PageReserved(pfn_to_page(start_pfn)))
366 for (i = 0; i < nr_pages; i++) {
367 page = pfn_to_page(start_pfn + i);
368 online_page(page);
369 onlined_pages++;
370 }
371 *(unsigned long *)arg = onlined_pages;
372 return 0;
373}
374
375
376int online_pages(unsigned long pfn, unsigned long nr_pages)
377{
Dave Hansen3947be12005-10-29 18:16:54 -0700378 unsigned long onlined_pages = 0;
379 struct zone *zone;
Yasunori Goto68113782006-06-23 02:03:11 -0700380 int need_zonelists_rebuild = 0;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700381 int nid;
382 int ret;
383 struct memory_notify arg;
Dave Hansen3947be12005-10-29 18:16:54 -0700384
Yasunori Goto7b78d332007-10-21 16:41:36 -0700385 arg.start_pfn = pfn;
386 arg.nr_pages = nr_pages;
387 arg.status_change_nid = -1;
388
389 nid = page_to_nid(pfn_to_page(pfn));
390 if (node_present_pages(nid) == 0)
391 arg.status_change_nid = nid;
392
393 ret = memory_notify(MEM_GOING_ONLINE, &arg);
394 ret = notifier_to_errno(ret);
395 if (ret) {
396 memory_notify(MEM_CANCEL_ONLINE, &arg);
397 return ret;
398 }
Dave Hansen3947be12005-10-29 18:16:54 -0700399 /*
400 * This doesn't need a lock to do pfn_to_page().
401 * The section can't be removed here because of the
Daniel Walkerda19cbc2008-02-04 23:35:47 -0800402 * memory_block->state_mutex.
Dave Hansen3947be12005-10-29 18:16:54 -0700403 */
404 zone = page_zone(pfn_to_page(pfn));
Yasunori Goto68113782006-06-23 02:03:11 -0700405 /*
406 * If this zone is not populated, then it is not in zonelist.
407 * This means the page allocator ignores this zone.
408 * So, zonelist must be updated after online.
409 */
410 if (!populated_zone(zone))
411 need_zonelists_rebuild = 1;
412
Geoff Levandfd8a4222008-05-14 16:05:50 -0700413 ret = walk_memory_resource(pfn, nr_pages, &onlined_pages,
KAMEZAWA Hiroyuki75884fb2007-10-16 01:26:10 -0700414 online_pages_range);
Geoff Levandfd8a4222008-05-14 16:05:50 -0700415 if (ret) {
416 printk(KERN_DEBUG "online_pages %lx at %lx failed\n",
417 nr_pages, pfn);
418 memory_notify(MEM_CANCEL_ONLINE, &arg);
419 return ret;
420 }
421
Dave Hansen3947be12005-10-29 18:16:54 -0700422 zone->present_pages += onlined_pages;
Yasunori Gotof2937be2006-03-09 17:33:51 -0800423 zone->zone_pgdat->node_present_pages += onlined_pages;
Dave Hansen3947be12005-10-29 18:16:54 -0700424
Dave Hansen61b13992005-10-29 18:16:56 -0700425 setup_per_zone_pages_min();
Christoph Lameter7ea15302007-10-16 01:25:29 -0700426 if (onlined_pages) {
427 kswapd_run(zone_to_nid(zone));
428 node_set_state(zone_to_nid(zone), N_HIGH_MEMORY);
429 }
Dave Hansen61b13992005-10-29 18:16:56 -0700430
Yasunori Goto68113782006-06-23 02:03:11 -0700431 if (need_zonelists_rebuild)
432 build_all_zonelists();
Kent Liu2f7f24e2008-07-23 21:28:18 -0700433 else
434 vm_total_pages = nr_free_pagecache_pages();
435
Chandra Seetharaman2d1d43f2006-09-29 02:01:25 -0700436 writeback_set_ratelimit();
Yasunori Goto7b78d332007-10-21 16:41:36 -0700437
438 if (onlined_pages)
439 memory_notify(MEM_ONLINE, &arg);
440
Dave Hansen3947be12005-10-29 18:16:54 -0700441 return 0;
442}
Keith Mannthey53947022006-09-30 23:27:08 -0700443#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
Yasunori Gotobc02af92006-06-27 02:53:30 -0700444
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700445static pg_data_t *hotadd_new_pgdat(int nid, u64 start)
446{
447 struct pglist_data *pgdat;
448 unsigned long zones_size[MAX_NR_ZONES] = {0};
449 unsigned long zholes_size[MAX_NR_ZONES] = {0};
450 unsigned long start_pfn = start >> PAGE_SHIFT;
451
452 pgdat = arch_alloc_nodedata(nid);
453 if (!pgdat)
454 return NULL;
455
456 arch_refresh_nodedata(nid, pgdat);
457
458 /* we can use NODE_DATA(nid) from here */
459
460 /* init node's zones as empty zones, we don't have any present pages.*/
Johannes Weiner9109fb72008-07-23 21:27:20 -0700461 free_area_init_node(nid, zones_size, start_pfn, zholes_size);
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700462
463 return pgdat;
464}
465
466static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
467{
468 arch_refresh_nodedata(nid, NULL);
469 arch_free_nodedata(pgdat);
470 return;
471}
472
KAMEZAWA Hiroyuki0a547032006-06-27 02:53:35 -0700473
Yasunori Gotobc02af92006-06-27 02:53:30 -0700474int add_memory(int nid, u64 start, u64 size)
475{
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700476 pg_data_t *pgdat = NULL;
477 int new_pgdat = 0;
KAMEZAWA Hiroyukiebd15302006-08-05 12:15:06 -0700478 struct resource *res;
Yasunori Gotobc02af92006-06-27 02:53:30 -0700479 int ret;
480
KAMEZAWA Hiroyukiebd15302006-08-05 12:15:06 -0700481 res = register_memory_resource(start, size);
482 if (!res)
483 return -EEXIST;
484
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700485 if (!node_online(nid)) {
486 pgdat = hotadd_new_pgdat(nid, start);
487 if (!pgdat)
488 return -ENOMEM;
489 new_pgdat = 1;
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700490 }
491
Yasunori Gotobc02af92006-06-27 02:53:30 -0700492 /* call arch's memory hotadd */
493 ret = arch_add_memory(nid, start, size);
494
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700495 if (ret < 0)
496 goto error;
497
Yasunori Goto0fc44152006-06-27 02:53:38 -0700498 /* we online node here. we can't roll back from here. */
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700499 node_set_online(nid);
500
Paul Jackson38837fc2006-09-29 02:01:16 -0700501 cpuset_track_online_nodes();
502
Yasunori Goto0fc44152006-06-27 02:53:38 -0700503 if (new_pgdat) {
504 ret = register_one_node(nid);
505 /*
506 * If sysfs file of new node can't create, cpu on the node
507 * can't be hot-added. There is no rollback way now.
508 * So, check by BUG_ON() to catch it reluctantly..
509 */
510 BUG_ON(ret);
511 }
512
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700513 return ret;
514error:
515 /* rollback pgdat allocation and others */
516 if (new_pgdat)
517 rollback_node_hotadd(nid, pgdat);
KAMEZAWA Hiroyukiebd15302006-08-05 12:15:06 -0700518 if (res)
519 release_memory_resource(res);
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700520
Yasunori Gotobc02af92006-06-27 02:53:30 -0700521 return ret;
522}
523EXPORT_SYMBOL_GPL(add_memory);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700524
525#ifdef CONFIG_MEMORY_HOTREMOVE
526/*
Badari Pulavarty5c755e92008-07-23 21:28:19 -0700527 * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
528 * set and the size of the free page is given by page_order(). Using this,
529 * the function determines if the pageblock contains only free pages.
530 * Due to buddy contraints, a free page at least the size of a pageblock will
531 * be located at the start of the pageblock
532 */
533static inline int pageblock_free(struct page *page)
534{
535 return PageBuddy(page) && page_order(page) >= pageblock_order;
536}
537
538/* Return the start of the next active pageblock after a given page */
539static struct page *next_active_pageblock(struct page *page)
540{
541 int pageblocks_stride;
542
543 /* Ensure the starting page is pageblock-aligned */
544 BUG_ON(page_to_pfn(page) & (pageblock_nr_pages - 1));
545
546 /* Move forward by at least 1 * pageblock_nr_pages */
547 pageblocks_stride = 1;
548
549 /* If the entire pageblock is free, move to the end of free page */
550 if (pageblock_free(page))
551 pageblocks_stride += page_order(page) - pageblock_order;
552
553 return page + (pageblocks_stride * pageblock_nr_pages);
554}
555
556/* Checks if this range of memory is likely to be hot-removable. */
557int is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages)
558{
559 int type;
560 struct page *page = pfn_to_page(start_pfn);
561 struct page *end_page = page + nr_pages;
562
563 /* Check the starting page of each pageblock within the range */
564 for (; page < end_page; page = next_active_pageblock(page)) {
565 type = get_pageblock_migratetype(page);
566
567 /*
568 * A pageblock containing MOVABLE or free pages is considered
569 * removable
570 */
571 if (type != MIGRATE_MOVABLE && !pageblock_free(page))
572 return 0;
573
574 /*
575 * A pageblock starting with a PageReserved page is not
576 * considered removable.
577 */
578 if (PageReserved(page))
579 return 0;
580 }
581
582 /* All pageblocks in the memory block are likely to be hot-removable */
583 return 1;
584}
585
586/*
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700587 * Confirm all pages in a range [start, end) is belongs to the same zone.
588 */
589static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn)
590{
591 unsigned long pfn;
592 struct zone *zone = NULL;
593 struct page *page;
594 int i;
595 for (pfn = start_pfn;
596 pfn < end_pfn;
597 pfn += MAX_ORDER_NR_PAGES) {
598 i = 0;
599 /* This is just a CONFIG_HOLES_IN_ZONE check.*/
600 while ((i < MAX_ORDER_NR_PAGES) && !pfn_valid_within(pfn + i))
601 i++;
602 if (i == MAX_ORDER_NR_PAGES)
603 continue;
604 page = pfn_to_page(pfn + i);
605 if (zone && page_zone(page) != zone)
606 return 0;
607 zone = page_zone(page);
608 }
609 return 1;
610}
611
612/*
613 * Scanning pfn is much easier than scanning lru list.
614 * Scan pfn from start to end and Find LRU page.
615 */
616int scan_lru_pages(unsigned long start, unsigned long end)
617{
618 unsigned long pfn;
619 struct page *page;
620 for (pfn = start; pfn < end; pfn++) {
621 if (pfn_valid(pfn)) {
622 page = pfn_to_page(pfn);
623 if (PageLRU(page))
624 return pfn;
625 }
626 }
627 return 0;
628}
629
630static struct page *
631hotremove_migrate_alloc(struct page *page,
632 unsigned long private,
633 int **x)
634{
635 /* This should be improoooooved!! */
636 return alloc_page(GFP_HIGHUSER_PAGECACHE);
637}
638
639
640#define NR_OFFLINE_AT_ONCE_PAGES (256)
641static int
642do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
643{
644 unsigned long pfn;
645 struct page *page;
646 int move_pages = NR_OFFLINE_AT_ONCE_PAGES;
647 int not_managed = 0;
648 int ret = 0;
649 LIST_HEAD(source);
650
651 for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) {
652 if (!pfn_valid(pfn))
653 continue;
654 page = pfn_to_page(pfn);
655 if (!page_count(page))
656 continue;
657 /*
658 * We can skip free pages. And we can only deal with pages on
659 * LRU.
660 */
Nick Piggin62695a82008-10-18 20:26:09 -0700661 ret = isolate_lru_page(page);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700662 if (!ret) { /* Success */
Nick Piggin62695a82008-10-18 20:26:09 -0700663 list_add_tail(&page->lru, &source);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700664 move_pages--;
665 } else {
666 /* Becasue we don't have big zone->lock. we should
667 check this again here. */
668 if (page_count(page))
669 not_managed++;
670#ifdef CONFIG_DEBUG_VM
671 printk(KERN_INFO "removing from LRU failed"
672 " %lx/%d/%lx\n",
673 pfn, page_count(page), page->flags);
674#endif
675 }
676 }
677 ret = -EBUSY;
678 if (not_managed) {
679 if (!list_empty(&source))
680 putback_lru_pages(&source);
681 goto out;
682 }
683 ret = 0;
684 if (list_empty(&source))
685 goto out;
686 /* this function returns # of failed pages */
687 ret = migrate_pages(&source, hotremove_migrate_alloc, 0);
688
689out:
690 return ret;
691}
692
693/*
694 * remove from free_area[] and mark all as Reserved.
695 */
696static int
697offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
698 void *data)
699{
700 __offline_isolated_pages(start, start + nr_pages);
701 return 0;
702}
703
704static void
705offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
706{
707 walk_memory_resource(start_pfn, end_pfn - start_pfn, NULL,
708 offline_isolated_pages_cb);
709}
710
711/*
712 * Check all pages in range, recoreded as memory resource, are isolated.
713 */
714static int
715check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
716 void *data)
717{
718 int ret;
719 long offlined = *(long *)data;
720 ret = test_pages_isolated(start_pfn, start_pfn + nr_pages);
721 offlined = nr_pages;
722 if (!ret)
723 *(long *)data += offlined;
724 return ret;
725}
726
727static long
728check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
729{
730 long offlined = 0;
731 int ret;
732
733 ret = walk_memory_resource(start_pfn, end_pfn - start_pfn, &offlined,
734 check_pages_isolated_cb);
735 if (ret < 0)
736 offlined = (long)ret;
737 return offlined;
738}
739
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700740int offline_pages(unsigned long start_pfn,
741 unsigned long end_pfn, unsigned long timeout)
742{
743 unsigned long pfn, nr_pages, expire;
744 long offlined_pages;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700745 int ret, drain, retry_max, node;
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700746 struct zone *zone;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700747 struct memory_notify arg;
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700748
749 BUG_ON(start_pfn >= end_pfn);
750 /* at least, alignment against pageblock is necessary */
751 if (!IS_ALIGNED(start_pfn, pageblock_nr_pages))
752 return -EINVAL;
753 if (!IS_ALIGNED(end_pfn, pageblock_nr_pages))
754 return -EINVAL;
755 /* This makes hotplug much easier...and readable.
756 we assume this for now. .*/
757 if (!test_pages_in_a_zone(start_pfn, end_pfn))
758 return -EINVAL;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700759
760 zone = page_zone(pfn_to_page(start_pfn));
761 node = zone_to_nid(zone);
762 nr_pages = end_pfn - start_pfn;
763
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700764 /* set above range as isolated */
765 ret = start_isolate_page_range(start_pfn, end_pfn);
766 if (ret)
767 return ret;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700768
769 arg.start_pfn = start_pfn;
770 arg.nr_pages = nr_pages;
771 arg.status_change_nid = -1;
772 if (nr_pages >= node_present_pages(node))
773 arg.status_change_nid = node;
774
775 ret = memory_notify(MEM_GOING_OFFLINE, &arg);
776 ret = notifier_to_errno(ret);
777 if (ret)
778 goto failed_removal;
779
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700780 pfn = start_pfn;
781 expire = jiffies + timeout;
782 drain = 0;
783 retry_max = 5;
784repeat:
785 /* start memory hot removal */
786 ret = -EAGAIN;
787 if (time_after(jiffies, expire))
788 goto failed_removal;
789 ret = -EINTR;
790 if (signal_pending(current))
791 goto failed_removal;
792 ret = 0;
793 if (drain) {
794 lru_add_drain_all();
795 flush_scheduled_work();
796 cond_resched();
Christoph Lameter9f8f2172008-02-04 22:29:11 -0800797 drain_all_pages();
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700798 }
799
800 pfn = scan_lru_pages(start_pfn, end_pfn);
801 if (pfn) { /* We have page on LRU */
802 ret = do_migrate_range(pfn, end_pfn);
803 if (!ret) {
804 drain = 1;
805 goto repeat;
806 } else {
807 if (ret < 0)
808 if (--retry_max == 0)
809 goto failed_removal;
810 yield();
811 drain = 1;
812 goto repeat;
813 }
814 }
815 /* drain all zone's lru pagevec, this is asyncronous... */
816 lru_add_drain_all();
817 flush_scheduled_work();
818 yield();
819 /* drain pcp pages , this is synchrouns. */
Christoph Lameter9f8f2172008-02-04 22:29:11 -0800820 drain_all_pages();
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700821 /* check again */
822 offlined_pages = check_pages_isolated(start_pfn, end_pfn);
823 if (offlined_pages < 0) {
824 ret = -EBUSY;
825 goto failed_removal;
826 }
827 printk(KERN_INFO "Offlined Pages %ld\n", offlined_pages);
828 /* Ok, all of our target is islaoted.
829 We cannot do rollback at this point. */
830 offline_isolated_pages(start_pfn, end_pfn);
KAMEZAWA Hiroyukidbc0e4c2007-11-14 16:59:12 -0800831 /* reset pagetype flags and makes migrate type to be MOVABLE */
832 undo_isolate_page_range(start_pfn, end_pfn);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700833 /* removal success */
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700834 zone->present_pages -= offlined_pages;
835 zone->zone_pgdat->node_present_pages -= offlined_pages;
836 totalram_pages -= offlined_pages;
837 num_physpages -= offlined_pages;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700838
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700839 vm_total_pages = nr_free_pagecache_pages();
840 writeback_set_ratelimit();
Yasunori Goto7b78d332007-10-21 16:41:36 -0700841
842 memory_notify(MEM_OFFLINE, &arg);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700843 return 0;
844
845failed_removal:
846 printk(KERN_INFO "memory offlining %lx to %lx failed\n",
847 start_pfn, end_pfn);
Yasunori Goto7b78d332007-10-21 16:41:36 -0700848 memory_notify(MEM_CANCEL_OFFLINE, &arg);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700849 /* pushback to free area */
850 undo_isolate_page_range(start_pfn, end_pfn);
Yasunori Goto7b78d332007-10-21 16:41:36 -0700851
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700852 return ret;
853}
Badari Pulavarty71088782008-10-18 20:25:58 -0700854
855int remove_memory(u64 start, u64 size)
856{
857 unsigned long start_pfn, end_pfn;
858
859 start_pfn = PFN_DOWN(start);
860 end_pfn = start_pfn + PFN_DOWN(size);
861 return offline_pages(start_pfn, end_pfn, 120 * HZ);
862}
KAMEZAWA Hiroyuki48e94192007-10-16 01:26:14 -0700863#else
864int remove_memory(u64 start, u64 size)
865{
866 return -EINVAL;
867}
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700868#endif /* CONFIG_MEMORY_HOTREMOVE */
Badari Pulavarty71088782008-10-18 20:25:58 -0700869EXPORT_SYMBOL_GPL(remove_memory);