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KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -07001/*
2 * linux/mm/page_isolation.c
3 */
4
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -07005#include <linux/mm.h>
6#include <linux/page-isolation.h>
7#include <linux/pageblock-flags.h>
Minchan Kimee6f5092012-07-31 16:43:50 -07008#include <linux/memory.h>
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -07009#include "internal.h"
10
Wen Congyangb023f462012-12-11 16:00:45 -080011int set_migratetype_isolate(struct page *page, bool skip_hwpoisoned_pages)
Minchan Kimee6f5092012-07-31 16:43:50 -070012{
13 struct zone *zone;
14 unsigned long flags, pfn;
15 struct memory_isolate_notify arg;
16 int notifier_ret;
17 int ret = -EBUSY;
18
19 zone = page_zone(page);
20
21 spin_lock_irqsave(&zone->lock, flags);
22
23 pfn = page_to_pfn(page);
24 arg.start_pfn = pfn;
25 arg.nr_pages = pageblock_nr_pages;
26 arg.pages_found = 0;
27
28 /*
29 * It may be possible to isolate a pageblock even if the
30 * migratetype is not MIGRATE_MOVABLE. The memory isolation
31 * notifier chain is used by balloon drivers to return the
32 * number of pages in a range that are held by the balloon
33 * driver to shrink memory. If all the pages are accounted for
34 * by balloons, are free, or on the LRU, isolation can continue.
35 * Later, for example, when memory hotplug notifier runs, these
36 * pages reported as "can be isolated" should be isolated(freed)
37 * by the balloon driver through the memory notifier chain.
38 */
39 notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg);
40 notifier_ret = notifier_to_errno(notifier_ret);
41 if (notifier_ret)
42 goto out;
43 /*
44 * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.
45 * We just check MOVABLE pages.
46 */
Wen Congyangb023f462012-12-11 16:00:45 -080047 if (!has_unmovable_pages(zone, page, arg.pages_found,
48 skip_hwpoisoned_pages))
Minchan Kimee6f5092012-07-31 16:43:50 -070049 ret = 0;
50
51 /*
52 * immobile means "not-on-lru" paes. If immobile is larger than
53 * removable-by-driver pages reported by notifier, we'll fail.
54 */
55
56out:
57 if (!ret) {
Bartlomiej Zolnierkiewicz2139cbe2012-10-08 16:32:00 -070058 unsigned long nr_pages;
Bartlomiej Zolnierkiewiczd1ce7492012-10-08 16:32:02 -070059 int migratetype = get_pageblock_migratetype(page);
Bartlomiej Zolnierkiewicz2139cbe2012-10-08 16:32:00 -070060
Bartlomiej Zolnierkiewicza4584312013-01-04 15:35:08 -080061 set_pageblock_migratetype(page, MIGRATE_ISOLATE);
Bartlomiej Zolnierkiewicz2139cbe2012-10-08 16:32:00 -070062 nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE);
63
Bartlomiej Zolnierkiewiczd1ce7492012-10-08 16:32:02 -070064 __mod_zone_freepage_state(zone, -nr_pages, migratetype);
Minchan Kimee6f5092012-07-31 16:43:50 -070065 }
66
67 spin_unlock_irqrestore(&zone->lock, flags);
68 if (!ret)
69 drain_all_pages();
70 return ret;
71}
72
73void unset_migratetype_isolate(struct page *page, unsigned migratetype)
74{
75 struct zone *zone;
Bartlomiej Zolnierkiewicz2139cbe2012-10-08 16:32:00 -070076 unsigned long flags, nr_pages;
77
Minchan Kimee6f5092012-07-31 16:43:50 -070078 zone = page_zone(page);
79 spin_lock_irqsave(&zone->lock, flags);
80 if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
81 goto out;
Bartlomiej Zolnierkiewicz2139cbe2012-10-08 16:32:00 -070082 nr_pages = move_freepages_block(zone, page, migratetype);
Bartlomiej Zolnierkiewiczd1ce7492012-10-08 16:32:02 -070083 __mod_zone_freepage_state(zone, nr_pages, migratetype);
Bartlomiej Zolnierkiewicza4584312013-01-04 15:35:08 -080084 set_pageblock_migratetype(page, migratetype);
Minchan Kimee6f5092012-07-31 16:43:50 -070085out:
86 spin_unlock_irqrestore(&zone->lock, flags);
87}
88
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -070089static inline struct page *
90__first_valid_page(unsigned long pfn, unsigned long nr_pages)
91{
92 int i;
93 for (i = 0; i < nr_pages; i++)
94 if (pfn_valid_within(pfn + i))
95 break;
96 if (unlikely(i == nr_pages))
97 return NULL;
98 return pfn_to_page(pfn + i);
99}
100
101/*
102 * start_isolate_page_range() -- make page-allocation-type of range of pages
103 * to be MIGRATE_ISOLATE.
104 * @start_pfn: The lower PFN of the range to be isolated.
105 * @end_pfn: The upper PFN of the range to be isolated.
Michal Nazarewicz0815f3d2012-04-03 15:06:15 +0200106 * @migratetype: migrate type to set in error recovery.
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700107 *
108 * Making page-allocation-type to be MIGRATE_ISOLATE means free pages in
109 * the range will never be allocated. Any free pages and pages freed in the
110 * future will not be allocated again.
111 *
112 * start_pfn/end_pfn must be aligned to pageblock_order.
113 * Returns 0 on success and -EBUSY if any part of range cannot be isolated.
114 */
Michal Nazarewicz0815f3d2012-04-03 15:06:15 +0200115int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
Wen Congyangb023f462012-12-11 16:00:45 -0800116 unsigned migratetype, bool skip_hwpoisoned_pages)
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700117{
118 unsigned long pfn;
119 unsigned long undo_pfn;
120 struct page *page;
121
122 BUG_ON((start_pfn) & (pageblock_nr_pages - 1));
123 BUG_ON((end_pfn) & (pageblock_nr_pages - 1));
124
125 for (pfn = start_pfn;
126 pfn < end_pfn;
127 pfn += pageblock_nr_pages) {
128 page = __first_valid_page(pfn, pageblock_nr_pages);
Wen Congyangb023f462012-12-11 16:00:45 -0800129 if (page &&
130 set_migratetype_isolate(page, skip_hwpoisoned_pages)) {
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700131 undo_pfn = pfn;
132 goto undo;
133 }
134 }
135 return 0;
136undo:
137 for (pfn = start_pfn;
KAMEZAWA Hiroyukidbc0e4c2007-11-14 16:59:12 -0800138 pfn < undo_pfn;
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700139 pfn += pageblock_nr_pages)
Michal Nazarewicz0815f3d2012-04-03 15:06:15 +0200140 unset_migratetype_isolate(pfn_to_page(pfn), migratetype);
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700141
142 return -EBUSY;
143}
144
145/*
146 * Make isolated pages available again.
147 */
Michal Nazarewicz0815f3d2012-04-03 15:06:15 +0200148int undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
149 unsigned migratetype)
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700150{
151 unsigned long pfn;
152 struct page *page;
153 BUG_ON((start_pfn) & (pageblock_nr_pages - 1));
154 BUG_ON((end_pfn) & (pageblock_nr_pages - 1));
155 for (pfn = start_pfn;
156 pfn < end_pfn;
157 pfn += pageblock_nr_pages) {
158 page = __first_valid_page(pfn, pageblock_nr_pages);
KAMEZAWA Hiroyukidbc0e4c2007-11-14 16:59:12 -0800159 if (!page || get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700160 continue;
Michal Nazarewicz0815f3d2012-04-03 15:06:15 +0200161 unset_migratetype_isolate(page, migratetype);
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700162 }
163 return 0;
164}
165/*
166 * Test all pages in the range is free(means isolated) or not.
167 * all pages in [start_pfn...end_pfn) must be in the same zone.
168 * zone->lock must be held before call this.
169 *
Michal Nazarewicz0815f3d2012-04-03 15:06:15 +0200170 * Returns 1 if all pages in the range are isolated.
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700171 */
172static int
Wen Congyangb023f462012-12-11 16:00:45 -0800173__test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn,
174 bool skip_hwpoisoned_pages)
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700175{
176 struct page *page;
177
178 while (pfn < end_pfn) {
179 if (!pfn_valid_within(pfn)) {
180 pfn++;
181 continue;
182 }
183 page = pfn_to_page(pfn);
Minchan Kim41d575a2012-10-08 16:32:14 -0700184 if (PageBuddy(page)) {
Minchan Kim435b4052012-10-08 16:32:16 -0700185 /*
186 * If race between isolatation and allocation happens,
187 * some free pages could be in MIGRATE_MOVABLE list
188 * although pageblock's migratation type of the page
189 * is MIGRATE_ISOLATE. Catch it and move the page into
190 * MIGRATE_ISOLATE list.
191 */
192 if (get_freepage_migratetype(page) != MIGRATE_ISOLATE) {
193 struct page *end_page;
194
195 end_page = page + (1 << page_order(page)) - 1;
196 move_freepages(page_zone(page), page, end_page,
197 MIGRATE_ISOLATE);
198 }
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700199 pfn += 1 << page_order(page);
Minchan Kim41d575a2012-10-08 16:32:14 -0700200 }
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700201 else if (page_count(page) == 0 &&
Minchan Kimb12c4ad2012-10-08 16:32:08 -0700202 get_freepage_migratetype(page) == MIGRATE_ISOLATE)
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700203 pfn += 1;
Wen Congyangb023f462012-12-11 16:00:45 -0800204 else if (skip_hwpoisoned_pages && PageHWPoison(page)) {
205 /*
206 * The HWPoisoned page may be not in buddy
207 * system, and page_count() is not 0.
208 */
209 pfn++;
210 continue;
211 }
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700212 else
213 break;
214 }
215 if (pfn < end_pfn)
216 return 0;
217 return 1;
218}
219
Wen Congyangb023f462012-12-11 16:00:45 -0800220int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
221 bool skip_hwpoisoned_pages)
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700222{
Gerald Schaefer6c1b7f62008-10-02 14:50:16 -0700223 unsigned long pfn, flags;
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700224 struct page *page;
Gerald Schaefer6c1b7f62008-10-02 14:50:16 -0700225 struct zone *zone;
226 int ret;
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700227
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700228 /*
229 * Note: pageblock_nr_page != MAX_ORDER. Then, chunks of free page
230 * is not aligned to pageblock_nr_pages.
231 * Then we just check pagetype fist.
232 */
233 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
234 page = __first_valid_page(pfn, pageblock_nr_pages);
KAMEZAWA Hiroyukidbc0e4c2007-11-14 16:59:12 -0800235 if (page && get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700236 break;
237 }
Gerald Schaefera70dcb92008-11-06 12:53:36 -0800238 page = __first_valid_page(start_pfn, end_pfn - start_pfn);
239 if ((pfn < end_pfn) || !page)
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700240 return -EBUSY;
241 /* Check all pages are free or Marked as ISOLATED */
Gerald Schaefera70dcb92008-11-06 12:53:36 -0800242 zone = page_zone(page);
Gerald Schaefer6c1b7f62008-10-02 14:50:16 -0700243 spin_lock_irqsave(&zone->lock, flags);
Wen Congyangb023f462012-12-11 16:00:45 -0800244 ret = __test_page_isolated_in_pageblock(start_pfn, end_pfn,
245 skip_hwpoisoned_pages);
Gerald Schaefer6c1b7f62008-10-02 14:50:16 -0700246 spin_unlock_irqrestore(&zone->lock, flags);
247 return ret ? 0 : -EBUSY;
KAMEZAWA Hiroyukia5d76b52007-10-16 01:26:11 -0700248}
Minchan Kim723a0642012-10-08 16:32:52 -0700249
250struct page *alloc_migrate_target(struct page *page, unsigned long private,
251 int **resultp)
252{
253 gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE;
254
255 if (PageHighMem(page))
256 gfp_mask |= __GFP_HIGHMEM;
257
258 return alloc_page(gfp_mask);
259}