blob: 833f854eabe50ad226696667db7e49d332840bb6 [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
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
65static void get_page_bootmem(unsigned long info, struct page *page, int magic)
66{
67 atomic_set(&page->_mapcount, magic);
68 SetPagePrivate(page);
69 set_page_private(page, info);
70 atomic_inc(&page->_count);
71}
72
73void put_page_bootmem(struct page *page)
74{
75 int magic;
76
77 magic = atomic_read(&page->_mapcount);
78 BUG_ON(magic >= -1);
79
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
89void register_page_bootmem_info_section(unsigned long start_pfn)
90{
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++)
122 get_page_bootmem(section_nr, page, MIX_INFO);
123
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
Yasunori Goto718127c2006-06-23 02:03:10 -0700192static int __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 Hansena2f3aa022007-01-10 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
Dave Hansen3947be12005-10-29 18:16:54 -0700219static int __add_section(struct zone *zone, unsigned long phys_start_pfn)
220{
Dave Hansen3947be12005-10-29 18:16:54 -0700221 int nr_pages = PAGES_PER_SECTION;
Dave Hansen3947be12005-10-29 18:16:54 -0700222 int ret;
223
KAMEZAWA Hiroyukiebd15302006-08-05 12:15:06 -0700224 if (pfn_valid(phys_start_pfn))
225 return -EEXIST;
226
Dave Hansen0b0acbe2005-10-29 18:16:55 -0700227 ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
Dave Hansen3947be12005-10-29 18:16:54 -0700228
229 if (ret < 0)
230 return ret;
231
Yasunori Goto718127c2006-06-23 02:03:10 -0700232 ret = __add_zone(zone, phys_start_pfn);
233
234 if (ret < 0)
235 return ret;
236
Dave Hansen3947be12005-10-29 18:16:54 -0700237 return register_new_memory(__pfn_to_section(phys_start_pfn));
238}
239
Yasunori Goto0c0a4a52008-04-28 02:13:34 -0700240#ifdef CONFIG_SPARSEMEM_VMEMMAP
241static int __remove_section(struct zone *zone, struct mem_section *ms)
242{
243 /*
244 * XXX: Freeing memmap with vmemmap is not implement yet.
245 * This should be removed later.
246 */
247 return -EBUSY;
248}
249#else
Badari Pulavartyea01ea92008-04-28 02:12:01 -0700250static int __remove_section(struct zone *zone, struct mem_section *ms)
251{
252 unsigned long flags;
253 struct pglist_data *pgdat = zone->zone_pgdat;
254 int ret = -EINVAL;
255
256 if (!valid_section(ms))
257 return ret;
258
259 ret = unregister_memory_section(ms);
260 if (ret)
261 return ret;
262
263 pgdat_resize_lock(pgdat, &flags);
264 sparse_remove_one_section(zone, ms);
265 pgdat_resize_unlock(pgdat, &flags);
266 return 0;
267}
Yasunori Goto0c0a4a52008-04-28 02:13:34 -0700268#endif
Badari Pulavartyea01ea92008-04-28 02:12:01 -0700269
Dave Hansen3947be12005-10-29 18:16:54 -0700270/*
271 * Reasonably generic function for adding memory. It is
272 * expected that archs that support memory hotplug will
273 * call this function after deciding the zone to which to
274 * add the new pages.
275 */
276int __add_pages(struct zone *zone, unsigned long phys_start_pfn,
277 unsigned long nr_pages)
278{
279 unsigned long i;
280 int err = 0;
KAMEZAWA Hiroyuki6f712712006-08-05 12:14:58 -0700281 int start_sec, end_sec;
282 /* during initialize mem_map, align hot-added range to section */
283 start_sec = pfn_to_section_nr(phys_start_pfn);
284 end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
Dave Hansen3947be12005-10-29 18:16:54 -0700285
KAMEZAWA Hiroyuki6f712712006-08-05 12:14:58 -0700286 for (i = start_sec; i <= end_sec; i++) {
287 err = __add_section(zone, i << PFN_SECTION_SHIFT);
Dave Hansen3947be12005-10-29 18:16:54 -0700288
KAMEZAWA Hiroyuki6f712712006-08-05 12:14:58 -0700289 /*
Simon Arlott183ff222007-10-20 01:27:18 +0200290 * EEXIST is finally dealt with by ioresource collision
KAMEZAWA Hiroyuki6f712712006-08-05 12:14:58 -0700291 * check. see add_memory() => register_memory_resource()
292 * Warning will be printed if there is collision.
Joel H Schoppbed120c2006-05-01 12:16:11 -0700293 */
294 if (err && (err != -EEXIST))
Dave Hansen3947be12005-10-29 18:16:54 -0700295 break;
KAMEZAWA Hiroyuki6f712712006-08-05 12:14:58 -0700296 err = 0;
Dave Hansen3947be12005-10-29 18:16:54 -0700297 }
298
299 return err;
300}
Joel H Schoppbed120c2006-05-01 12:16:11 -0700301EXPORT_SYMBOL_GPL(__add_pages);
Dave Hansen3947be12005-10-29 18:16:54 -0700302
Badari Pulavartyea01ea92008-04-28 02:12:01 -0700303/**
304 * __remove_pages() - remove sections of pages from a zone
305 * @zone: zone from which pages need to be removed
306 * @phys_start_pfn: starting pageframe (must be aligned to start of a section)
307 * @nr_pages: number of pages to remove (must be multiple of section size)
308 *
309 * Generic helper function to remove section mappings and sysfs entries
310 * for the section of the memory we are removing. Caller needs to make
311 * sure that pages are marked reserved and zones are adjust properly by
312 * calling offline_pages().
313 */
314int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
315 unsigned long nr_pages)
316{
317 unsigned long i, ret = 0;
318 int sections_to_remove;
319
320 /*
321 * We can only remove entire sections
322 */
323 BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK);
324 BUG_ON(nr_pages % PAGES_PER_SECTION);
325
326 release_mem_region(phys_start_pfn << PAGE_SHIFT, nr_pages * PAGE_SIZE);
327
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;
331 ret = __remove_section(zone, __pfn_to_section(pfn));
332 if (ret)
333 break;
334 }
335 return ret;
336}
337EXPORT_SYMBOL_GPL(__remove_pages);
338
Jeremy Fitzhardinge180c06e2008-04-28 02:12:03 -0700339void online_page(struct page *page)
340{
341 totalram_pages++;
342 num_physpages++;
343
344#ifdef CONFIG_HIGHMEM
345 if (PageHighMem(page))
346 totalhigh_pages++;
347#endif
348
349#ifdef CONFIG_FLATMEM
350 max_mapnr = max(page_to_pfn(page), max_mapnr);
351#endif
352
353 ClearPageReserved(page);
354 init_page_count(page);
355 __free_page(page);
356}
357
KAMEZAWA Hiroyuki75884fb2007-10-16 01:26:10 -0700358static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
359 void *arg)
Dave Hansen3947be12005-10-29 18:16:54 -0700360{
361 unsigned long i;
KAMEZAWA Hiroyuki75884fb2007-10-16 01:26:10 -0700362 unsigned long onlined_pages = *(unsigned long *)arg;
363 struct page *page;
364 if (PageReserved(pfn_to_page(start_pfn)))
365 for (i = 0; i < nr_pages; i++) {
366 page = pfn_to_page(start_pfn + i);
367 online_page(page);
368 onlined_pages++;
369 }
370 *(unsigned long *)arg = onlined_pages;
371 return 0;
372}
373
374
375int online_pages(unsigned long pfn, unsigned long nr_pages)
376{
Dave Hansen3947be12005-10-29 18:16:54 -0700377 unsigned long onlined_pages = 0;
378 struct zone *zone;
Yasunori Goto68113782006-06-23 02:03:11 -0700379 int need_zonelists_rebuild = 0;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700380 int nid;
381 int ret;
382 struct memory_notify arg;
Dave Hansen3947be12005-10-29 18:16:54 -0700383
Yasunori Goto7b78d332007-10-21 16:41:36 -0700384 arg.start_pfn = pfn;
385 arg.nr_pages = nr_pages;
386 arg.status_change_nid = -1;
387
388 nid = page_to_nid(pfn_to_page(pfn));
389 if (node_present_pages(nid) == 0)
390 arg.status_change_nid = nid;
391
392 ret = memory_notify(MEM_GOING_ONLINE, &arg);
393 ret = notifier_to_errno(ret);
394 if (ret) {
395 memory_notify(MEM_CANCEL_ONLINE, &arg);
396 return ret;
397 }
Dave Hansen3947be12005-10-29 18:16:54 -0700398 /*
399 * This doesn't need a lock to do pfn_to_page().
400 * The section can't be removed here because of the
Daniel Walkerda19cbc2008-02-04 23:35:47 -0800401 * memory_block->state_mutex.
Dave Hansen3947be12005-10-29 18:16:54 -0700402 */
403 zone = page_zone(pfn_to_page(pfn));
Yasunori Goto68113782006-06-23 02:03:11 -0700404 /*
405 * If this zone is not populated, then it is not in zonelist.
406 * This means the page allocator ignores this zone.
407 * So, zonelist must be updated after online.
408 */
409 if (!populated_zone(zone))
410 need_zonelists_rebuild = 1;
411
Geoff Levandfd8a4222008-05-14 16:05:50 -0700412 ret = walk_memory_resource(pfn, nr_pages, &onlined_pages,
KAMEZAWA Hiroyuki75884fb2007-10-16 01:26:10 -0700413 online_pages_range);
Geoff Levandfd8a4222008-05-14 16:05:50 -0700414 if (ret) {
415 printk(KERN_DEBUG "online_pages %lx at %lx failed\n",
416 nr_pages, pfn);
417 memory_notify(MEM_CANCEL_ONLINE, &arg);
418 return ret;
419 }
420
Dave Hansen3947be12005-10-29 18:16:54 -0700421 zone->present_pages += onlined_pages;
Yasunori Gotof2937be2006-03-09 17:33:51 -0800422 zone->zone_pgdat->node_present_pages += onlined_pages;
Dave Hansen3947be12005-10-29 18:16:54 -0700423
Dave Hansen61b13992005-10-29 18:16:56 -0700424 setup_per_zone_pages_min();
Christoph Lameter7ea15302007-10-16 01:25:29 -0700425 if (onlined_pages) {
426 kswapd_run(zone_to_nid(zone));
427 node_set_state(zone_to_nid(zone), N_HIGH_MEMORY);
428 }
Dave Hansen61b13992005-10-29 18:16:56 -0700429
Yasunori Goto68113782006-06-23 02:03:11 -0700430 if (need_zonelists_rebuild)
431 build_all_zonelists();
KAMEZAWA Hiroyuki5a4d4362006-06-23 02:03:47 -0700432 vm_total_pages = nr_free_pagecache_pages();
Chandra Seetharaman2d1d43f2006-09-29 02:01:25 -0700433 writeback_set_ratelimit();
Yasunori Goto7b78d332007-10-21 16:41:36 -0700434
435 if (onlined_pages)
436 memory_notify(MEM_ONLINE, &arg);
437
Dave Hansen3947be12005-10-29 18:16:54 -0700438 return 0;
439}
Keith Mannthey53947022006-09-30 23:27:08 -0700440#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
Yasunori Gotobc02af92006-06-27 02:53:30 -0700441
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700442static pg_data_t *hotadd_new_pgdat(int nid, u64 start)
443{
444 struct pglist_data *pgdat;
445 unsigned long zones_size[MAX_NR_ZONES] = {0};
446 unsigned long zholes_size[MAX_NR_ZONES] = {0};
447 unsigned long start_pfn = start >> PAGE_SHIFT;
448
449 pgdat = arch_alloc_nodedata(nid);
450 if (!pgdat)
451 return NULL;
452
453 arch_refresh_nodedata(nid, pgdat);
454
455 /* we can use NODE_DATA(nid) from here */
456
457 /* init node's zones as empty zones, we don't have any present pages.*/
458 free_area_init_node(nid, pgdat, zones_size, start_pfn, zholes_size);
459
460 return pgdat;
461}
462
463static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
464{
465 arch_refresh_nodedata(nid, NULL);
466 arch_free_nodedata(pgdat);
467 return;
468}
469
KAMEZAWA Hiroyuki0a547032006-06-27 02:53:35 -0700470
Yasunori Gotobc02af92006-06-27 02:53:30 -0700471int add_memory(int nid, u64 start, u64 size)
472{
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700473 pg_data_t *pgdat = NULL;
474 int new_pgdat = 0;
KAMEZAWA Hiroyukiebd15302006-08-05 12:15:06 -0700475 struct resource *res;
Yasunori Gotobc02af92006-06-27 02:53:30 -0700476 int ret;
477
KAMEZAWA Hiroyukiebd15302006-08-05 12:15:06 -0700478 res = register_memory_resource(start, size);
479 if (!res)
480 return -EEXIST;
481
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700482 if (!node_online(nid)) {
483 pgdat = hotadd_new_pgdat(nid, start);
484 if (!pgdat)
485 return -ENOMEM;
486 new_pgdat = 1;
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700487 }
488
Yasunori Gotobc02af92006-06-27 02:53:30 -0700489 /* call arch's memory hotadd */
490 ret = arch_add_memory(nid, start, size);
491
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700492 if (ret < 0)
493 goto error;
494
Yasunori Goto0fc44152006-06-27 02:53:38 -0700495 /* we online node here. we can't roll back from here. */
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700496 node_set_online(nid);
497
Paul Jackson38837fc2006-09-29 02:01:16 -0700498 cpuset_track_online_nodes();
499
Yasunori Goto0fc44152006-06-27 02:53:38 -0700500 if (new_pgdat) {
501 ret = register_one_node(nid);
502 /*
503 * If sysfs file of new node can't create, cpu on the node
504 * can't be hot-added. There is no rollback way now.
505 * So, check by BUG_ON() to catch it reluctantly..
506 */
507 BUG_ON(ret);
508 }
509
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700510 return ret;
511error:
512 /* rollback pgdat allocation and others */
513 if (new_pgdat)
514 rollback_node_hotadd(nid, pgdat);
KAMEZAWA Hiroyukiebd15302006-08-05 12:15:06 -0700515 if (res)
516 release_memory_resource(res);
Yasunori Goto9af3c2d2006-06-27 02:53:34 -0700517
Yasunori Gotobc02af92006-06-27 02:53:30 -0700518 return ret;
519}
520EXPORT_SYMBOL_GPL(add_memory);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700521
522#ifdef CONFIG_MEMORY_HOTREMOVE
523/*
524 * Confirm all pages in a range [start, end) is belongs to the same zone.
525 */
526static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn)
527{
528 unsigned long pfn;
529 struct zone *zone = NULL;
530 struct page *page;
531 int i;
532 for (pfn = start_pfn;
533 pfn < end_pfn;
534 pfn += MAX_ORDER_NR_PAGES) {
535 i = 0;
536 /* This is just a CONFIG_HOLES_IN_ZONE check.*/
537 while ((i < MAX_ORDER_NR_PAGES) && !pfn_valid_within(pfn + i))
538 i++;
539 if (i == MAX_ORDER_NR_PAGES)
540 continue;
541 page = pfn_to_page(pfn + i);
542 if (zone && page_zone(page) != zone)
543 return 0;
544 zone = page_zone(page);
545 }
546 return 1;
547}
548
549/*
550 * Scanning pfn is much easier than scanning lru list.
551 * Scan pfn from start to end and Find LRU page.
552 */
553int scan_lru_pages(unsigned long start, unsigned long end)
554{
555 unsigned long pfn;
556 struct page *page;
557 for (pfn = start; pfn < end; pfn++) {
558 if (pfn_valid(pfn)) {
559 page = pfn_to_page(pfn);
560 if (PageLRU(page))
561 return pfn;
562 }
563 }
564 return 0;
565}
566
567static struct page *
568hotremove_migrate_alloc(struct page *page,
569 unsigned long private,
570 int **x)
571{
572 /* This should be improoooooved!! */
573 return alloc_page(GFP_HIGHUSER_PAGECACHE);
574}
575
576
577#define NR_OFFLINE_AT_ONCE_PAGES (256)
578static int
579do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
580{
581 unsigned long pfn;
582 struct page *page;
583 int move_pages = NR_OFFLINE_AT_ONCE_PAGES;
584 int not_managed = 0;
585 int ret = 0;
586 LIST_HEAD(source);
587
588 for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) {
589 if (!pfn_valid(pfn))
590 continue;
591 page = pfn_to_page(pfn);
592 if (!page_count(page))
593 continue;
594 /*
595 * We can skip free pages. And we can only deal with pages on
596 * LRU.
597 */
598 ret = isolate_lru_page(page, &source);
599 if (!ret) { /* Success */
600 move_pages--;
601 } else {
602 /* Becasue we don't have big zone->lock. we should
603 check this again here. */
604 if (page_count(page))
605 not_managed++;
606#ifdef CONFIG_DEBUG_VM
607 printk(KERN_INFO "removing from LRU failed"
608 " %lx/%d/%lx\n",
609 pfn, page_count(page), page->flags);
610#endif
611 }
612 }
613 ret = -EBUSY;
614 if (not_managed) {
615 if (!list_empty(&source))
616 putback_lru_pages(&source);
617 goto out;
618 }
619 ret = 0;
620 if (list_empty(&source))
621 goto out;
622 /* this function returns # of failed pages */
623 ret = migrate_pages(&source, hotremove_migrate_alloc, 0);
624
625out:
626 return ret;
627}
628
629/*
630 * remove from free_area[] and mark all as Reserved.
631 */
632static int
633offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
634 void *data)
635{
636 __offline_isolated_pages(start, start + nr_pages);
637 return 0;
638}
639
640static void
641offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
642{
643 walk_memory_resource(start_pfn, end_pfn - start_pfn, NULL,
644 offline_isolated_pages_cb);
645}
646
647/*
648 * Check all pages in range, recoreded as memory resource, are isolated.
649 */
650static int
651check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
652 void *data)
653{
654 int ret;
655 long offlined = *(long *)data;
656 ret = test_pages_isolated(start_pfn, start_pfn + nr_pages);
657 offlined = nr_pages;
658 if (!ret)
659 *(long *)data += offlined;
660 return ret;
661}
662
663static long
664check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
665{
666 long offlined = 0;
667 int ret;
668
669 ret = walk_memory_resource(start_pfn, end_pfn - start_pfn, &offlined,
670 check_pages_isolated_cb);
671 if (ret < 0)
672 offlined = (long)ret;
673 return offlined;
674}
675
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700676int offline_pages(unsigned long start_pfn,
677 unsigned long end_pfn, unsigned long timeout)
678{
679 unsigned long pfn, nr_pages, expire;
680 long offlined_pages;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700681 int ret, drain, retry_max, node;
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700682 struct zone *zone;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700683 struct memory_notify arg;
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700684
685 BUG_ON(start_pfn >= end_pfn);
686 /* at least, alignment against pageblock is necessary */
687 if (!IS_ALIGNED(start_pfn, pageblock_nr_pages))
688 return -EINVAL;
689 if (!IS_ALIGNED(end_pfn, pageblock_nr_pages))
690 return -EINVAL;
691 /* This makes hotplug much easier...and readable.
692 we assume this for now. .*/
693 if (!test_pages_in_a_zone(start_pfn, end_pfn))
694 return -EINVAL;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700695
696 zone = page_zone(pfn_to_page(start_pfn));
697 node = zone_to_nid(zone);
698 nr_pages = end_pfn - start_pfn;
699
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700700 /* set above range as isolated */
701 ret = start_isolate_page_range(start_pfn, end_pfn);
702 if (ret)
703 return ret;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700704
705 arg.start_pfn = start_pfn;
706 arg.nr_pages = nr_pages;
707 arg.status_change_nid = -1;
708 if (nr_pages >= node_present_pages(node))
709 arg.status_change_nid = node;
710
711 ret = memory_notify(MEM_GOING_OFFLINE, &arg);
712 ret = notifier_to_errno(ret);
713 if (ret)
714 goto failed_removal;
715
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700716 pfn = start_pfn;
717 expire = jiffies + timeout;
718 drain = 0;
719 retry_max = 5;
720repeat:
721 /* start memory hot removal */
722 ret = -EAGAIN;
723 if (time_after(jiffies, expire))
724 goto failed_removal;
725 ret = -EINTR;
726 if (signal_pending(current))
727 goto failed_removal;
728 ret = 0;
729 if (drain) {
730 lru_add_drain_all();
731 flush_scheduled_work();
732 cond_resched();
Christoph Lameter9f8f2172008-02-04 22:29:11 -0800733 drain_all_pages();
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700734 }
735
736 pfn = scan_lru_pages(start_pfn, end_pfn);
737 if (pfn) { /* We have page on LRU */
738 ret = do_migrate_range(pfn, end_pfn);
739 if (!ret) {
740 drain = 1;
741 goto repeat;
742 } else {
743 if (ret < 0)
744 if (--retry_max == 0)
745 goto failed_removal;
746 yield();
747 drain = 1;
748 goto repeat;
749 }
750 }
751 /* drain all zone's lru pagevec, this is asyncronous... */
752 lru_add_drain_all();
753 flush_scheduled_work();
754 yield();
755 /* drain pcp pages , this is synchrouns. */
Christoph Lameter9f8f2172008-02-04 22:29:11 -0800756 drain_all_pages();
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700757 /* check again */
758 offlined_pages = check_pages_isolated(start_pfn, end_pfn);
759 if (offlined_pages < 0) {
760 ret = -EBUSY;
761 goto failed_removal;
762 }
763 printk(KERN_INFO "Offlined Pages %ld\n", offlined_pages);
764 /* Ok, all of our target is islaoted.
765 We cannot do rollback at this point. */
766 offline_isolated_pages(start_pfn, end_pfn);
KAMEZAWA Hiroyukidbc0e4c2007-11-14 16:59:12 -0800767 /* reset pagetype flags and makes migrate type to be MOVABLE */
768 undo_isolate_page_range(start_pfn, end_pfn);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700769 /* removal success */
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700770 zone->present_pages -= offlined_pages;
771 zone->zone_pgdat->node_present_pages -= offlined_pages;
772 totalram_pages -= offlined_pages;
773 num_physpages -= offlined_pages;
Yasunori Goto7b78d332007-10-21 16:41:36 -0700774
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700775 vm_total_pages = nr_free_pagecache_pages();
776 writeback_set_ratelimit();
Yasunori Goto7b78d332007-10-21 16:41:36 -0700777
778 memory_notify(MEM_OFFLINE, &arg);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700779 return 0;
780
781failed_removal:
782 printk(KERN_INFO "memory offlining %lx to %lx failed\n",
783 start_pfn, end_pfn);
Yasunori Goto7b78d332007-10-21 16:41:36 -0700784 memory_notify(MEM_CANCEL_OFFLINE, &arg);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700785 /* pushback to free area */
786 undo_isolate_page_range(start_pfn, end_pfn);
Yasunori Goto7b78d332007-10-21 16:41:36 -0700787
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700788 return ret;
789}
KAMEZAWA Hiroyuki48e94192007-10-16 01:26:14 -0700790#else
791int remove_memory(u64 start, u64 size)
792{
793 return -EINVAL;
794}
795EXPORT_SYMBOL_GPL(remove_memory);
KAMEZAWA Hiroyuki0c0e6192007-10-16 01:26:12 -0700796#endif /* CONFIG_MEMORY_HOTREMOVE */