Commit | Line | Data |
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a5d76b54 KH |
1 | /* |
2 | * linux/mm/page_isolation.c | |
3 | */ | |
4 | ||
a5d76b54 KH |
5 | #include <linux/mm.h> |
6 | #include <linux/page-isolation.h> | |
7 | #include <linux/pageblock-flags.h> | |
ee6f509c | 8 | #include <linux/memory.h> |
a5d76b54 KH |
9 | #include "internal.h" |
10 | ||
b023f468 | 11 | int set_migratetype_isolate(struct page *page, bool skip_hwpoisoned_pages) |
ee6f509c MK |
12 | { |
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 | */ | |
b023f468 WC |
47 | if (!has_unmovable_pages(zone, page, arg.pages_found, |
48 | skip_hwpoisoned_pages)) | |
ee6f509c MK |
49 | 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 | ||
56 | out: | |
57 | if (!ret) { | |
2139cbe6 | 58 | unsigned long nr_pages; |
d1ce749a | 59 | int migratetype = get_pageblock_migratetype(page); |
2139cbe6 | 60 | |
a458431e | 61 | set_pageblock_migratetype(page, MIGRATE_ISOLATE); |
2139cbe6 BZ |
62 | nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE); |
63 | ||
d1ce749a | 64 | __mod_zone_freepage_state(zone, -nr_pages, migratetype); |
ee6f509c MK |
65 | } |
66 | ||
67 | spin_unlock_irqrestore(&zone->lock, flags); | |
68 | if (!ret) | |
69 | drain_all_pages(); | |
70 | return ret; | |
71 | } | |
72 | ||
73 | void unset_migratetype_isolate(struct page *page, unsigned migratetype) | |
74 | { | |
75 | struct zone *zone; | |
2139cbe6 BZ |
76 | unsigned long flags, nr_pages; |
77 | ||
ee6f509c MK |
78 | zone = page_zone(page); |
79 | spin_lock_irqsave(&zone->lock, flags); | |
80 | if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE) | |
81 | goto out; | |
2139cbe6 | 82 | nr_pages = move_freepages_block(zone, page, migratetype); |
d1ce749a | 83 | __mod_zone_freepage_state(zone, nr_pages, migratetype); |
a458431e | 84 | set_pageblock_migratetype(page, migratetype); |
ee6f509c MK |
85 | out: |
86 | spin_unlock_irqrestore(&zone->lock, flags); | |
87 | } | |
88 | ||
a5d76b54 KH |
89 | static 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. | |
0815f3d8 | 106 | * @migratetype: migrate type to set in error recovery. |
a5d76b54 KH |
107 | * |
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 | */ | |
0815f3d8 | 115 | int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn, |
b023f468 | 116 | unsigned migratetype, bool skip_hwpoisoned_pages) |
a5d76b54 KH |
117 | { |
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); | |
b023f468 WC |
129 | if (page && |
130 | set_migratetype_isolate(page, skip_hwpoisoned_pages)) { | |
a5d76b54 KH |
131 | undo_pfn = pfn; |
132 | goto undo; | |
133 | } | |
134 | } | |
135 | return 0; | |
136 | undo: | |
137 | for (pfn = start_pfn; | |
dbc0e4ce | 138 | pfn < undo_pfn; |
a5d76b54 | 139 | pfn += pageblock_nr_pages) |
0815f3d8 | 140 | unset_migratetype_isolate(pfn_to_page(pfn), migratetype); |
a5d76b54 KH |
141 | |
142 | return -EBUSY; | |
143 | } | |
144 | ||
145 | /* | |
146 | * Make isolated pages available again. | |
147 | */ | |
0815f3d8 MN |
148 | int undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn, |
149 | unsigned migratetype) | |
a5d76b54 KH |
150 | { |
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); | |
dbc0e4ce | 159 | if (!page || get_pageblock_migratetype(page) != MIGRATE_ISOLATE) |
a5d76b54 | 160 | continue; |
0815f3d8 | 161 | unset_migratetype_isolate(page, migratetype); |
a5d76b54 KH |
162 | } |
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 | * | |
0815f3d8 | 170 | * Returns 1 if all pages in the range are isolated. |
a5d76b54 KH |
171 | */ |
172 | static int | |
b023f468 WC |
173 | __test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn, |
174 | bool skip_hwpoisoned_pages) | |
a5d76b54 KH |
175 | { |
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); | |
41d575ad | 184 | if (PageBuddy(page)) { |
435b405c MK |
185 | /* |
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 | } | |
a5d76b54 | 199 | pfn += 1 << page_order(page); |
41d575ad | 200 | } |
a5d76b54 | 201 | else if (page_count(page) == 0 && |
b12c4ad1 | 202 | get_freepage_migratetype(page) == MIGRATE_ISOLATE) |
a5d76b54 | 203 | pfn += 1; |
b023f468 WC |
204 | 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 | } | |
a5d76b54 KH |
212 | else |
213 | break; | |
214 | } | |
215 | if (pfn < end_pfn) | |
216 | return 0; | |
217 | return 1; | |
218 | } | |
219 | ||
b023f468 WC |
220 | int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn, |
221 | bool skip_hwpoisoned_pages) | |
a5d76b54 | 222 | { |
6c1b7f68 | 223 | unsigned long pfn, flags; |
a5d76b54 | 224 | struct page *page; |
6c1b7f68 GS |
225 | struct zone *zone; |
226 | int ret; | |
a5d76b54 | 227 | |
a5d76b54 KH |
228 | /* |
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); | |
dbc0e4ce | 235 | if (page && get_pageblock_migratetype(page) != MIGRATE_ISOLATE) |
a5d76b54 KH |
236 | break; |
237 | } | |
a70dcb96 GS |
238 | page = __first_valid_page(start_pfn, end_pfn - start_pfn); |
239 | if ((pfn < end_pfn) || !page) | |
a5d76b54 KH |
240 | return -EBUSY; |
241 | /* Check all pages are free or Marked as ISOLATED */ | |
a70dcb96 | 242 | zone = page_zone(page); |
6c1b7f68 | 243 | spin_lock_irqsave(&zone->lock, flags); |
b023f468 WC |
244 | ret = __test_page_isolated_in_pageblock(start_pfn, end_pfn, |
245 | skip_hwpoisoned_pages); | |
6c1b7f68 GS |
246 | spin_unlock_irqrestore(&zone->lock, flags); |
247 | return ret ? 0 : -EBUSY; | |
a5d76b54 | 248 | } |
723a0644 MK |
249 | |
250 | struct 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 | } |