blob: 821dee596377fadcd93e2116e117eea0a0340e97 [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>
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -070025#include <linux/delay.h>
26#include <linux/migrate.h>
27#include <linux/page-isolation.h>
Badari Pulavarty71088782008-10-18 20:25:58 -070028#include <linux/pfn.h>
Dave Hansen3947be12005-10-29 18:16:54 -070029
30#include <asm/tlbflush.h>
31
Adrian Bunk1e5ad9a2008-04-28 20:40:08 +030032#include "internal.h"
33
Keith Mannthey45e0b782006-09-30 23:27:09 -070034/* add this memory to iomem resource */
35static struct resource *register_memory_resource(u64 start, u64 size)
36{
37 struct resource *res;
38 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
39 BUG_ON(!res);
40
41 res->name = "System RAM";
42 res->start = start;
43 res->end = start + size - 1;
Yasunori Goto887c3cb2007-11-14 16:59:20 -080044 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
Keith Mannthey45e0b782006-09-30 23:27:09 -070045 if (request_resource(&iomem_resource, res) < 0) {
46 printk("System RAM resource %llx - %llx cannot be added\n",
47 (unsigned long long)res->start, (unsigned long long)res->end);
48 kfree(res);
49 res = NULL;
50 }
51 return res;
52}
53
54static void release_memory_resource(struct resource *res)
55{
56 if (!res)
57 return;
58 release_resource(res);
59 kfree(res);
60 return;
61}
62
Keith Mannthey53947022006-09-30 23:27:08 -070063#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
Yasunori Goto04753272008-04-28 02:13:31 -070064#ifndef CONFIG_SPARSEMEM_VMEMMAP
Yasunori Gotoaf370fb2008-07-23 21:28:17 -070065static void get_page_bootmem(unsigned long info, struct page *page, int type)
Yasunori Goto04753272008-04-28 02:13:31 -070066{
Yasunori Gotoaf370fb2008-07-23 21:28:17 -070067 atomic_set(&page->_mapcount, type);
Yasunori Goto04753272008-04-28 02:13:31 -070068 SetPagePrivate(page);
69 set_page_private(page, info);
70 atomic_inc(&page->_count);
71}
72
73void put_page_bootmem(struct page *page)
74{
Yasunori Gotoaf370fb2008-07-23 21:28:17 -070075 int type;
Yasunori Goto04753272008-04-28 02:13:31 -070076
Yasunori Gotoaf370fb2008-07-23 21:28:17 -070077 type = atomic_read(&page->_mapcount);
78 BUG_ON(type >= -1);
Yasunori Goto04753272008-04-28 02:13:31 -070079
80 if (atomic_dec_return(&page->_count) == 1) {
81 ClearPagePrivate(page);
82 set_page_private(page, 0);
83 reset_page_mapcount(page);
84 __free_pages_bootmem(page, 0);
85 }
86
87}
88
Adrian Bunkd92bc312008-07-23 21:28:12 -070089static void register_page_bootmem_info_section(unsigned long start_pfn)
Yasunori Goto04753272008-04-28 02:13:31 -070090{
91 unsigned long *usemap, mapsize, section_nr, i;
92 struct mem_section *ms;
93 struct page *page, *memmap;
94
95 if (!pfn_valid(start_pfn))
96 return;
97
98 section_nr = pfn_to_section_nr(start_pfn);
99 ms = __nr_to_section(section_nr);
100
101 /* Get section's memmap address */
102 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
103
104 /*
105 * Get page for the memmap's phys address
106 * XXX: need more consideration for sparse_vmemmap...
107 */
108 page = virt_to_page(memmap);
109 mapsize = sizeof(struct page) * PAGES_PER_SECTION;
110 mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT;
111
112 /* remember memmap's page */
113 for (i = 0; i < mapsize; i++, page++)
114 get_page_bootmem(section_nr, page, SECTION_INFO);
115
116 usemap = __nr_to_section(section_nr)->pageblock_flags;
117 page = virt_to_page(usemap);
118
119 mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT;
120
121 for (i = 0; i < mapsize; i++, page++)
Yasunori Gotoaf370fb2008-07-23 21:28:17 -0700122 get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
Yasunori Goto04753272008-04-28 02:13:31 -0700123
124}
125
126void register_page_bootmem_info_node(struct pglist_data *pgdat)
127{
128 unsigned long i, pfn, end_pfn, nr_pages;
129 int node = pgdat->node_id;
130 struct page *page;
131 struct zone *zone;
132
133 nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT;
134 page = virt_to_page(pgdat);
135
136 for (i = 0; i < nr_pages; i++, page++)
137 get_page_bootmem(node, page, NODE_INFO);
138
139 zone = &pgdat->node_zones[0];
140 for (; zone < pgdat->node_zones + MAX_NR_ZONES - 1; zone++) {
141 if (zone->wait_table) {
142 nr_pages = zone->wait_table_hash_nr_entries
143 * sizeof(wait_queue_head_t);
144 nr_pages = PAGE_ALIGN(nr_pages) >> PAGE_SHIFT;
145 page = virt_to_page(zone->wait_table);
146
147 for (i = 0; i < nr_pages; i++, page++)
148 get_page_bootmem(node, page, NODE_INFO);
149 }
150 }
151
152 pfn = pgdat->node_start_pfn;
153 end_pfn = pfn + pgdat->node_spanned_pages;
154
155 /* register_section info */
156 for (; pfn < end_pfn; pfn += PAGES_PER_SECTION)
157 register_page_bootmem_info_section(pfn);
158
159}
160#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
161
Heiko Carstens76cdd582008-05-14 16:05:52 -0700162static void grow_zone_span(struct zone *zone, unsigned long start_pfn,
163 unsigned long end_pfn)
164{
165 unsigned long old_zone_end_pfn;
166
167 zone_span_writelock(zone);
168
169 old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
170 if (start_pfn < zone->zone_start_pfn)
171 zone->zone_start_pfn = start_pfn;
172
173 zone->spanned_pages = max(old_zone_end_pfn, end_pfn) -
174 zone->zone_start_pfn;
175
176 zone_span_writeunlock(zone);
177}
178
179static void grow_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn,
180 unsigned long end_pfn)
181{
182 unsigned long old_pgdat_end_pfn =
183 pgdat->node_start_pfn + pgdat->node_spanned_pages;
184
185 if (start_pfn < pgdat->node_start_pfn)
186 pgdat->node_start_pfn = start_pfn;
187
188 pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) -
189 pgdat->node_start_pfn;
190}
191
Al Viro31168482008-11-22 17:33:24 +0000192static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn)
Dave Hansen3947be12005-10-29 18:16:54 -0700193{
194 struct pglist_data *pgdat = zone->zone_pgdat;
195 int nr_pages = PAGES_PER_SECTION;
196 int nid = pgdat->node_id;
197 int zone_type;
Heiko Carstens76cdd582008-05-14 16:05:52 -0700198 unsigned long flags;
Dave Hansen3947be12005-10-29 18:16:54 -0700199
200 zone_type = zone - pgdat->node_zones;
Heiko Carstens76cdd582008-05-14 16:05:52 -0700201 if (!zone->wait_table) {
202 int ret;
203
204 ret = init_currently_empty_zone(zone, phys_start_pfn,
205 nr_pages, MEMMAP_HOTPLUG);
206 if (ret)
207 return ret;
208 }
209 pgdat_resize_lock(zone->zone_pgdat, &flags);
210 grow_zone_span(zone, phys_start_pfn, phys_start_pfn + nr_pages);
211 grow_pgdat_span(zone->zone_pgdat, phys_start_pfn,
212 phys_start_pfn + nr_pages);
213 pgdat_resize_unlock(zone->zone_pgdat, &flags);
Dave Hansena2f3aa02007-01-10 23:15:30 -0800214 memmap_init_zone(nr_pages, nid, zone_type,
215 phys_start_pfn, MEMMAP_HOTPLUG);
Yasunori Goto718127c2006-06-23 02:03:10 -0700216 return 0;
Dave Hansen3947be12005-10-29 18:16:54 -0700217}
218
Gary Hadec04fc582009-01-06 14:39:14 -0800219static int __meminit __add_section(int nid, struct zone *zone,
220 unsigned long phys_start_pfn)
Dave Hansen3947be12005-10-29 18:16:54 -0700221{
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
Gary Hadec04fc582009-01-06 14:39:14 -0800238 return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
Dave Hansen3947be12005-10-29 18:16:54 -0700239}
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 */
Gary Hadec04fc582009-01-06 14:39:14 -0800277int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,
278 unsigned long nr_pages)
Dave Hansen3947be12005-10-29 18:16:54 -0700279{
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++) {
Gary Hadec04fc582009-01-06 14:39:14 -0800288 err = __add_section(nid, 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{
Jan Beulich4738e1b2009-09-21 17:03:03 -0700342 unsigned long pfn = page_to_pfn(page);
343
Jeremy Fitzhardinge180c06e2008-04-28 02:12:03 -0700344 totalram_pages++;
Jan Beulich4738e1b2009-09-21 17:03:03 -0700345 if (pfn >= num_physpages)
346 num_physpages = pfn + 1;
Jeremy Fitzhardinge180c06e2008-04-28 02:12:03 -0700347
348#ifdef CONFIG_HIGHMEM
349 if (PageHighMem(page))
350 totalhigh_pages++;
351#endif
352
353#ifdef CONFIG_FLATMEM
354 max_mapnr = max(page_to_pfn(page), max_mapnr);
355#endif
356
357 ClearPageReserved(page);
358 init_page_count(page);
359 __free_page(page);
360}
361
KAMEZAWA Hiroyuki75884fb2007-10-16 01:26:10 -0700362static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
363 void *arg)
Dave Hansen3947be12005-10-29 18:16:54 -0700364{
365 unsigned long i;
KAMEZAWA Hiroyuki75884fb2007-10-16 01:26:10 -0700366 unsigned long onlined_pages = *(unsigned long *)arg;
367 struct page *page;
368 if (PageReserved(pfn_to_page(start_pfn)))
369 for (i = 0; i < nr_pages; i++) {
370 page = pfn_to_page(start_pfn + i);
371 online_page(page);
372 onlined_pages++;
373 }
374 *(unsigned long *)arg = onlined_pages;
375 return 0;
376}
377
378
379int online_pages(unsigned long pfn, unsigned long nr_pages)
380{
Dave Hansen3947be12005-10-29 18:16:54 -0700381 unsigned long onlined_pages = 0;
382 struct zone *zone;
Yasunori Goto68113782006-06-23 02:03:11 -0700383 int need_zonelists_rebuild = 0;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700384 int nid;
385 int ret;
386 struct memory_notify arg;
Dave Hansen3947be12005-10-29 18:16:54 -0700387
Yasunori Goto7b78d332007-10-21 16:41:36 -0700388 arg.start_pfn = pfn;
389 arg.nr_pages = nr_pages;
390 arg.status_change_nid = -1;
391
392 nid = page_to_nid(pfn_to_page(pfn));
393 if (node_present_pages(nid) == 0)
394 arg.status_change_nid = nid;
395
396 ret = memory_notify(MEM_GOING_ONLINE, &arg);
397 ret = notifier_to_errno(ret);
398 if (ret) {
399 memory_notify(MEM_CANCEL_ONLINE, &arg);
400 return ret;
401 }
Dave Hansen3947be12005-10-29 18:16:54 -0700402 /*
403 * This doesn't need a lock to do pfn_to_page().
404 * The section can't be removed here because of the
Daniel Walkerda19cbc2008-02-04 23:35:47 -0800405 * memory_block->state_mutex.
Dave Hansen3947be12005-10-29 18:16:54 -0700406 */
407 zone = page_zone(pfn_to_page(pfn));
Yasunori Goto68113782006-06-23 02:03:11 -0700408 /*
409 * If this zone is not populated, then it is not in zonelist.
410 * This means the page allocator ignores this zone.
411 * So, zonelist must be updated after online.
412 */
413 if (!populated_zone(zone))
414 need_zonelists_rebuild = 1;
415
KAMEZAWA Hiroyuki908eedc2009-09-22 16:45:46 -0700416 ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages,
KAMEZAWA Hiroyuki75884fb2007-10-16 01:26:10 -0700417 online_pages_range);
Geoff Levandfd8a4222008-05-14 16:05:50 -0700418 if (ret) {
419 printk(KERN_DEBUG "online_pages %lx at %lx failed\n",
420 nr_pages, pfn);
421 memory_notify(MEM_CANCEL_ONLINE, &arg);
422 return ret;
423 }
424
Dave Hansen3947be12005-10-29 18:16:54 -0700425 zone->present_pages += onlined_pages;
Yasunori Gotof2937be2006-03-09 17:33:51 -0800426 zone->zone_pgdat->node_present_pages += onlined_pages;
Dave Hansen3947be12005-10-29 18:16:54 -0700427
Shaohua Li112067f2009-09-21 17:01:16 -0700428 zone_pcp_update(zone);
Minchan Kimbc75d332009-06-16 15:32:48 -0700429 setup_per_zone_wmarks();
Minchan Kimbce73942009-06-16 15:32:50 -0700430 calculate_zone_inactive_ratio(zone);
Christoph Lameter7ea15302007-10-16 01:25:29 -0700431 if (onlined_pages) {
432 kswapd_run(zone_to_nid(zone));
433 node_set_state(zone_to_nid(zone), N_HIGH_MEMORY);
434 }
Dave Hansen61b13992005-10-29 18:16:56 -0700435
Yasunori Goto68113782006-06-23 02:03:11 -0700436 if (need_zonelists_rebuild)
437 build_all_zonelists();
Kent Liu2f7f24e2008-07-23 21:28:18 -0700438 else
439 vm_total_pages = nr_free_pagecache_pages();
440
Chandra Seetharaman2d1d43f2006-09-29 02:01:25 -0700441 writeback_set_ratelimit();
Yasunori Goto7b78d332007-10-21 16:41:36 -0700442
443 if (onlined_pages)
444 memory_notify(MEM_ONLINE, &arg);
445
Dave Hansen3947be12005-10-29 18:16:54 -0700446 return 0;
447}
Keith Mannthey53947022006-09-30 23:27:08 -0700448#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
Yasunori Gotobc02af92006-06-27 02:53:30 -0700449
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700450static pg_data_t *hotadd_new_pgdat(int nid, u64 start)
451{
452 struct pglist_data *pgdat;
453 unsigned long zones_size[MAX_NR_ZONES] = {0};
454 unsigned long zholes_size[MAX_NR_ZONES] = {0};
455 unsigned long start_pfn = start >> PAGE_SHIFT;
456
457 pgdat = arch_alloc_nodedata(nid);
458 if (!pgdat)
459 return NULL;
460
461 arch_refresh_nodedata(nid, pgdat);
462
463 /* we can use NODE_DATA(nid) from here */
464
465 /* init node's zones as empty zones, we don't have any present pages.*/
Johannes Weiner9109fb72008-07-23 21:27:20 -0700466 free_area_init_node(nid, zones_size, start_pfn, zholes_size);
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700467
468 return pgdat;
469}
470
471static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
472{
473 arch_refresh_nodedata(nid, NULL);
474 arch_free_nodedata(pgdat);
475 return;
476}
477
KAMEZAWA Hiroyuki0a547032006-06-27 02:53:35 -0700478
Al Viro31168482008-11-22 17:33:24 +0000479/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
480int __ref add_memory(int nid, u64 start, u64 size)
Yasunori Gotobc02af92006-06-27 02:53:30 -0700481{
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700482 pg_data_t *pgdat = NULL;
483 int new_pgdat = 0;
KAMEZAWA Hiroyukiebd15302006-08-05 12:15:06 -0700484 struct resource *res;
Yasunori Gotobc02af92006-06-27 02:53:30 -0700485 int ret;
486
KAMEZAWA Hiroyukiebd15302006-08-05 12:15:06 -0700487 res = register_memory_resource(start, size);
488 if (!res)
489 return -EEXIST;
490
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700491 if (!node_online(nid)) {
492 pgdat = hotadd_new_pgdat(nid, start);
493 if (!pgdat)
494 return -ENOMEM;
495 new_pgdat = 1;
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700496 }
497
Yasunori Gotobc02af92006-06-27 02:53:30 -0700498 /* call arch's memory hotadd */
499 ret = arch_add_memory(nid, start, size);
500
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700501 if (ret < 0)
502 goto error;
503
Yasunori Goto0fc44152006-06-27 02:53:38 -0700504 /* we online node here. we can't roll back from here. */
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700505 node_set_online(nid);
506
Yasunori Goto0fc44152006-06-27 02:53:38 -0700507 if (new_pgdat) {
508 ret = register_one_node(nid);
509 /*
510 * If sysfs file of new node can't create, cpu on the node
511 * can't be hot-added. There is no rollback way now.
512 * So, check by BUG_ON() to catch it reluctantly..
513 */
514 BUG_ON(ret);
515 }
516
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700517 return ret;
518error:
519 /* rollback pgdat allocation and others */
520 if (new_pgdat)
521 rollback_node_hotadd(nid, pgdat);
KAMEZAWA Hiroyukiebd15302006-08-05 12:15:06 -0700522 if (res)
523 release_memory_resource(res);
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700524
Yasunori Gotobc02af92006-06-27 02:53:30 -0700525 return ret;
526}
527EXPORT_SYMBOL_GPL(add_memory);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700528
529#ifdef CONFIG_MEMORY_HOTREMOVE
530/*
Badari Pulavarty5c755e92008-07-23 21:28:19 -0700531 * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
532 * set and the size of the free page is given by page_order(). Using this,
533 * the function determines if the pageblock contains only free pages.
534 * Due to buddy contraints, a free page at least the size of a pageblock will
535 * be located at the start of the pageblock
536 */
537static inline int pageblock_free(struct page *page)
538{
539 return PageBuddy(page) && page_order(page) >= pageblock_order;
540}
541
542/* Return the start of the next active pageblock after a given page */
543static struct page *next_active_pageblock(struct page *page)
544{
545 int pageblocks_stride;
546
547 /* Ensure the starting page is pageblock-aligned */
548 BUG_ON(page_to_pfn(page) & (pageblock_nr_pages - 1));
549
550 /* Move forward by at least 1 * pageblock_nr_pages */
551 pageblocks_stride = 1;
552
553 /* If the entire pageblock is free, move to the end of free page */
554 if (pageblock_free(page))
555 pageblocks_stride += page_order(page) - pageblock_order;
556
557 return page + (pageblocks_stride * pageblock_nr_pages);
558}
559
560/* Checks if this range of memory is likely to be hot-removable. */
561int is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages)
562{
563 int type;
564 struct page *page = pfn_to_page(start_pfn);
565 struct page *end_page = page + nr_pages;
566
567 /* Check the starting page of each pageblock within the range */
568 for (; page < end_page; page = next_active_pageblock(page)) {
569 type = get_pageblock_migratetype(page);
570
571 /*
572 * A pageblock containing MOVABLE or free pages is considered
573 * removable
574 */
575 if (type != MIGRATE_MOVABLE && !pageblock_free(page))
576 return 0;
577
578 /*
579 * A pageblock starting with a PageReserved page is not
580 * considered removable.
581 */
582 if (PageReserved(page))
583 return 0;
584 }
585
586 /* All pageblocks in the memory block are likely to be hot-removable */
587 return 1;
588}
589
590/*
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700591 * Confirm all pages in a range [start, end) is belongs to the same zone.
592 */
593static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn)
594{
595 unsigned long pfn;
596 struct zone *zone = NULL;
597 struct page *page;
598 int i;
599 for (pfn = start_pfn;
600 pfn < end_pfn;
601 pfn += MAX_ORDER_NR_PAGES) {
602 i = 0;
603 /* This is just a CONFIG_HOLES_IN_ZONE check.*/
604 while ((i < MAX_ORDER_NR_PAGES) && !pfn_valid_within(pfn + i))
605 i++;
606 if (i == MAX_ORDER_NR_PAGES)
607 continue;
608 page = pfn_to_page(pfn + i);
609 if (zone && page_zone(page) != zone)
610 return 0;
611 zone = page_zone(page);
612 }
613 return 1;
614}
615
616/*
617 * Scanning pfn is much easier than scanning lru list.
618 * Scan pfn from start to end and Find LRU page.
619 */
620int scan_lru_pages(unsigned long start, unsigned long end)
621{
622 unsigned long pfn;
623 struct page *page;
624 for (pfn = start; pfn < end; pfn++) {
625 if (pfn_valid(pfn)) {
626 page = pfn_to_page(pfn);
627 if (PageLRU(page))
628 return pfn;
629 }
630 }
631 return 0;
632}
633
634static struct page *
Hugh Dickins3c1d4372009-01-06 14:39:23 -0800635hotremove_migrate_alloc(struct page *page, unsigned long private, int **x)
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700636{
Hugh Dickins3c1d4372009-01-06 14:39:23 -0800637 /* This should be improooooved!! */
638 return alloc_page(GFP_HIGHUSER_MOVABLE);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700639}
640
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700641#define NR_OFFLINE_AT_ONCE_PAGES (256)
642static int
643do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
644{
645 unsigned long pfn;
646 struct page *page;
647 int move_pages = NR_OFFLINE_AT_ONCE_PAGES;
648 int not_managed = 0;
649 int ret = 0;
650 LIST_HEAD(source);
651
652 for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) {
653 if (!pfn_valid(pfn))
654 continue;
655 page = pfn_to_page(pfn);
656 if (!page_count(page))
657 continue;
658 /*
659 * We can skip free pages. And we can only deal with pages on
660 * LRU.
661 */
Nick Piggin62695a82008-10-18 20:26:09 -0700662 ret = isolate_lru_page(page);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700663 if (!ret) { /* Success */
Nick Piggin62695a82008-10-18 20:26:09 -0700664 list_add_tail(&page->lru, &source);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700665 move_pages--;
666 } else {
667 /* Becasue we don't have big zone->lock. we should
668 check this again here. */
669 if (page_count(page))
670 not_managed++;
671#ifdef CONFIG_DEBUG_VM
672 printk(KERN_INFO "removing from LRU failed"
673 " %lx/%d/%lx\n",
674 pfn, page_count(page), page->flags);
675#endif
676 }
677 }
678 ret = -EBUSY;
679 if (not_managed) {
680 if (!list_empty(&source))
681 putback_lru_pages(&source);
682 goto out;
683 }
684 ret = 0;
685 if (list_empty(&source))
686 goto out;
687 /* this function returns # of failed pages */
688 ret = migrate_pages(&source, hotremove_migrate_alloc, 0);
689
690out:
691 return ret;
692}
693
694/*
695 * remove from free_area[] and mark all as Reserved.
696 */
697static int
698offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
699 void *data)
700{
701 __offline_isolated_pages(start, start + nr_pages);
702 return 0;
703}
704
705static void
706offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
707{
KAMEZAWA Hiroyuki908eedc2009-09-22 16:45:46 -0700708 walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL,
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700709 offline_isolated_pages_cb);
710}
711
712/*
713 * Check all pages in range, recoreded as memory resource, are isolated.
714 */
715static int
716check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
717 void *data)
718{
719 int ret;
720 long offlined = *(long *)data;
721 ret = test_pages_isolated(start_pfn, start_pfn + nr_pages);
722 offlined = nr_pages;
723 if (!ret)
724 *(long *)data += offlined;
725 return ret;
726}
727
728static long
729check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
730{
731 long offlined = 0;
732 int ret;
733
KAMEZAWA Hiroyuki908eedc2009-09-22 16:45:46 -0700734 ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined,
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700735 check_pages_isolated_cb);
736 if (ret < 0)
737 offlined = (long)ret;
738 return offlined;
739}
740
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700741int offline_pages(unsigned long start_pfn,
742 unsigned long end_pfn, unsigned long timeout)
743{
744 unsigned long pfn, nr_pages, expire;
745 long offlined_pages;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700746 int ret, drain, retry_max, node;
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700747 struct zone *zone;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700748 struct memory_notify arg;
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700749
750 BUG_ON(start_pfn >= end_pfn);
751 /* at least, alignment against pageblock is necessary */
752 if (!IS_ALIGNED(start_pfn, pageblock_nr_pages))
753 return -EINVAL;
754 if (!IS_ALIGNED(end_pfn, pageblock_nr_pages))
755 return -EINVAL;
756 /* This makes hotplug much easier...and readable.
757 we assume this for now. .*/
758 if (!test_pages_in_a_zone(start_pfn, end_pfn))
759 return -EINVAL;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700760
761 zone = page_zone(pfn_to_page(start_pfn));
762 node = zone_to_nid(zone);
763 nr_pages = end_pfn - start_pfn;
764
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700765 /* set above range as isolated */
766 ret = start_isolate_page_range(start_pfn, end_pfn);
767 if (ret)
768 return ret;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700769
770 arg.start_pfn = start_pfn;
771 arg.nr_pages = nr_pages;
772 arg.status_change_nid = -1;
773 if (nr_pages >= node_present_pages(node))
774 arg.status_change_nid = node;
775
776 ret = memory_notify(MEM_GOING_OFFLINE, &arg);
777 ret = notifier_to_errno(ret);
778 if (ret)
779 goto failed_removal;
780
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700781 pfn = start_pfn;
782 expire = jiffies + timeout;
783 drain = 0;
784 retry_max = 5;
785repeat:
786 /* start memory hot removal */
787 ret = -EAGAIN;
788 if (time_after(jiffies, expire))
789 goto failed_removal;
790 ret = -EINTR;
791 if (signal_pending(current))
792 goto failed_removal;
793 ret = 0;
794 if (drain) {
795 lru_add_drain_all();
796 flush_scheduled_work();
797 cond_resched();
Christoph Lameter9f8f2172008-02-04 22:29:11 -0800798 drain_all_pages();
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700799 }
800
801 pfn = scan_lru_pages(start_pfn, end_pfn);
802 if (pfn) { /* We have page on LRU */
803 ret = do_migrate_range(pfn, end_pfn);
804 if (!ret) {
805 drain = 1;
806 goto repeat;
807 } else {
808 if (ret < 0)
809 if (--retry_max == 0)
810 goto failed_removal;
811 yield();
812 drain = 1;
813 goto repeat;
814 }
815 }
816 /* drain all zone's lru pagevec, this is asyncronous... */
817 lru_add_drain_all();
818 flush_scheduled_work();
819 yield();
820 /* drain pcp pages , this is synchrouns. */
Christoph Lameter9f8f2172008-02-04 22:29:11 -0800821 drain_all_pages();
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700822 /* check again */
823 offlined_pages = check_pages_isolated(start_pfn, end_pfn);
824 if (offlined_pages < 0) {
825 ret = -EBUSY;
826 goto failed_removal;
827 }
828 printk(KERN_INFO "Offlined Pages %ld\n", offlined_pages);
829 /* Ok, all of our target is islaoted.
830 We cannot do rollback at this point. */
831 offline_isolated_pages(start_pfn, end_pfn);
KAMEZAWA Hiroyukidbc0e4c2007-11-14 16:59:12 -0800832 /* reset pagetype flags and makes migrate type to be MOVABLE */
833 undo_isolate_page_range(start_pfn, end_pfn);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700834 /* removal success */
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700835 zone->present_pages -= offlined_pages;
836 zone->zone_pgdat->node_present_pages -= offlined_pages;
837 totalram_pages -= offlined_pages;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700838
Minchan Kimbce73942009-06-16 15:32:50 -0700839 setup_per_zone_wmarks();
840 calculate_zone_inactive_ratio(zone);
841
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700842 vm_total_pages = nr_free_pagecache_pages();
843 writeback_set_ratelimit();
Yasunori Goto7b78d332007-10-21 16:41:36 -0700844
845 memory_notify(MEM_OFFLINE, &arg);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700846 return 0;
847
848failed_removal:
849 printk(KERN_INFO "memory offlining %lx to %lx failed\n",
850 start_pfn, end_pfn);
Yasunori Goto7b78d332007-10-21 16:41:36 -0700851 memory_notify(MEM_CANCEL_OFFLINE, &arg);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700852 /* pushback to free area */
853 undo_isolate_page_range(start_pfn, end_pfn);
Yasunori Goto7b78d332007-10-21 16:41:36 -0700854
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700855 return ret;
856}
Badari Pulavarty71088782008-10-18 20:25:58 -0700857
858int remove_memory(u64 start, u64 size)
859{
860 unsigned long start_pfn, end_pfn;
861
862 start_pfn = PFN_DOWN(start);
863 end_pfn = start_pfn + PFN_DOWN(size);
864 return offline_pages(start_pfn, end_pfn, 120 * HZ);
865}
KAMEZAWA Hiroyuki48e94192007-10-16 01:26:14 -0700866#else
867int remove_memory(u64 start, u64 size)
868{
869 return -EINVAL;
870}
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700871#endif /* CONFIG_MEMORY_HOTREMOVE */
Badari Pulavarty71088782008-10-18 20:25:58 -0700872EXPORT_SYMBOL_GPL(remove_memory);