Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/mm/hugetlb.c
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
File MIME type: text/plain
File size: 6264 byte(s)
Tag kernel26-2.6.12-alx-r9
1 | /* |
2 | * Generic hugetlb support. |
3 | * (C) William Irwin, April 2004 |
4 | */ |
5 | #include <linux/gfp.h> |
6 | #include <linux/list.h> |
7 | #include <linux/init.h> |
8 | #include <linux/module.h> |
9 | #include <linux/mm.h> |
10 | #include <linux/hugetlb.h> |
11 | #include <linux/sysctl.h> |
12 | #include <linux/highmem.h> |
13 | #include <linux/nodemask.h> |
14 | |
15 | const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; |
16 | static unsigned long nr_huge_pages, free_huge_pages; |
17 | unsigned long max_huge_pages; |
18 | static struct list_head hugepage_freelists[MAX_NUMNODES]; |
19 | static unsigned int nr_huge_pages_node[MAX_NUMNODES]; |
20 | static unsigned int free_huge_pages_node[MAX_NUMNODES]; |
21 | static DEFINE_SPINLOCK(hugetlb_lock); |
22 | |
23 | static void enqueue_huge_page(struct page *page) |
24 | { |
25 | int nid = page_to_nid(page); |
26 | list_add(&page->lru, &hugepage_freelists[nid]); |
27 | free_huge_pages++; |
28 | free_huge_pages_node[nid]++; |
29 | } |
30 | |
31 | static struct page *dequeue_huge_page(void) |
32 | { |
33 | int nid = numa_node_id(); |
34 | struct page *page = NULL; |
35 | |
36 | if (list_empty(&hugepage_freelists[nid])) { |
37 | for (nid = 0; nid < MAX_NUMNODES; ++nid) |
38 | if (!list_empty(&hugepage_freelists[nid])) |
39 | break; |
40 | } |
41 | if (nid >= 0 && nid < MAX_NUMNODES && |
42 | !list_empty(&hugepage_freelists[nid])) { |
43 | page = list_entry(hugepage_freelists[nid].next, |
44 | struct page, lru); |
45 | list_del(&page->lru); |
46 | free_huge_pages--; |
47 | free_huge_pages_node[nid]--; |
48 | } |
49 | return page; |
50 | } |
51 | |
52 | static struct page *alloc_fresh_huge_page(void) |
53 | { |
54 | static int nid = 0; |
55 | struct page *page; |
56 | page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN, |
57 | HUGETLB_PAGE_ORDER); |
58 | nid = (nid + 1) % num_online_nodes(); |
59 | if (page) { |
60 | nr_huge_pages++; |
61 | nr_huge_pages_node[page_to_nid(page)]++; |
62 | } |
63 | return page; |
64 | } |
65 | |
66 | void free_huge_page(struct page *page) |
67 | { |
68 | BUG_ON(page_count(page)); |
69 | |
70 | INIT_LIST_HEAD(&page->lru); |
71 | page[1].mapping = NULL; |
72 | |
73 | spin_lock(&hugetlb_lock); |
74 | enqueue_huge_page(page); |
75 | spin_unlock(&hugetlb_lock); |
76 | } |
77 | |
78 | struct page *alloc_huge_page(void) |
79 | { |
80 | struct page *page; |
81 | int i; |
82 | |
83 | spin_lock(&hugetlb_lock); |
84 | page = dequeue_huge_page(); |
85 | if (!page) { |
86 | spin_unlock(&hugetlb_lock); |
87 | return NULL; |
88 | } |
89 | spin_unlock(&hugetlb_lock); |
90 | set_page_count(page, 1); |
91 | page[1].mapping = (void *)free_huge_page; |
92 | for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); ++i) |
93 | clear_highpage(&page[i]); |
94 | return page; |
95 | } |
96 | |
97 | static int __init hugetlb_init(void) |
98 | { |
99 | unsigned long i; |
100 | struct page *page; |
101 | |
102 | for (i = 0; i < MAX_NUMNODES; ++i) |
103 | INIT_LIST_HEAD(&hugepage_freelists[i]); |
104 | |
105 | for (i = 0; i < max_huge_pages; ++i) { |
106 | page = alloc_fresh_huge_page(); |
107 | if (!page) |
108 | break; |
109 | spin_lock(&hugetlb_lock); |
110 | enqueue_huge_page(page); |
111 | spin_unlock(&hugetlb_lock); |
112 | } |
113 | max_huge_pages = free_huge_pages = nr_huge_pages = i; |
114 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); |
115 | return 0; |
116 | } |
117 | module_init(hugetlb_init); |
118 | |
119 | static int __init hugetlb_setup(char *s) |
120 | { |
121 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) |
122 | max_huge_pages = 0; |
123 | return 1; |
124 | } |
125 | __setup("hugepages=", hugetlb_setup); |
126 | |
127 | #ifdef CONFIG_SYSCTL |
128 | static void update_and_free_page(struct page *page) |
129 | { |
130 | int i; |
131 | nr_huge_pages--; |
132 | nr_huge_pages_node[page_zone(page)->zone_pgdat->node_id]--; |
133 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { |
134 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | |
135 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | |
136 | 1 << PG_private | 1<< PG_writeback); |
137 | set_page_count(&page[i], 0); |
138 | } |
139 | set_page_count(page, 1); |
140 | __free_pages(page, HUGETLB_PAGE_ORDER); |
141 | } |
142 | |
143 | #ifdef CONFIG_HIGHMEM |
144 | static void try_to_free_low(unsigned long count) |
145 | { |
146 | int i, nid; |
147 | for (i = 0; i < MAX_NUMNODES; ++i) { |
148 | struct page *page, *next; |
149 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { |
150 | if (PageHighMem(page)) |
151 | continue; |
152 | list_del(&page->lru); |
153 | update_and_free_page(page); |
154 | nid = page_zone(page)->zone_pgdat->node_id; |
155 | free_huge_pages--; |
156 | free_huge_pages_node[nid]--; |
157 | if (count >= nr_huge_pages) |
158 | return; |
159 | } |
160 | } |
161 | } |
162 | #else |
163 | static inline void try_to_free_low(unsigned long count) |
164 | { |
165 | } |
166 | #endif |
167 | |
168 | static unsigned long set_max_huge_pages(unsigned long count) |
169 | { |
170 | while (count > nr_huge_pages) { |
171 | struct page *page = alloc_fresh_huge_page(); |
172 | if (!page) |
173 | return nr_huge_pages; |
174 | spin_lock(&hugetlb_lock); |
175 | enqueue_huge_page(page); |
176 | spin_unlock(&hugetlb_lock); |
177 | } |
178 | if (count >= nr_huge_pages) |
179 | return nr_huge_pages; |
180 | |
181 | spin_lock(&hugetlb_lock); |
182 | try_to_free_low(count); |
183 | while (count < nr_huge_pages) { |
184 | struct page *page = dequeue_huge_page(); |
185 | if (!page) |
186 | break; |
187 | update_and_free_page(page); |
188 | } |
189 | spin_unlock(&hugetlb_lock); |
190 | return nr_huge_pages; |
191 | } |
192 | |
193 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
194 | struct file *file, void __user *buffer, |
195 | size_t *length, loff_t *ppos) |
196 | { |
197 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
198 | max_huge_pages = set_max_huge_pages(max_huge_pages); |
199 | return 0; |
200 | } |
201 | #endif /* CONFIG_SYSCTL */ |
202 | |
203 | int hugetlb_report_meminfo(char *buf) |
204 | { |
205 | return sprintf(buf, |
206 | "HugePages_Total: %5lu\n" |
207 | "HugePages_Free: %5lu\n" |
208 | "Hugepagesize: %5lu kB\n", |
209 | nr_huge_pages, |
210 | free_huge_pages, |
211 | HPAGE_SIZE/1024); |
212 | } |
213 | |
214 | int hugetlb_report_node_meminfo(int nid, char *buf) |
215 | { |
216 | return sprintf(buf, |
217 | "Node %d HugePages_Total: %5u\n" |
218 | "Node %d HugePages_Free: %5u\n", |
219 | nid, nr_huge_pages_node[nid], |
220 | nid, free_huge_pages_node[nid]); |
221 | } |
222 | |
223 | int is_hugepage_mem_enough(size_t size) |
224 | { |
225 | return (size + ~HPAGE_MASK)/HPAGE_SIZE <= free_huge_pages; |
226 | } |
227 | |
228 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
229 | unsigned long hugetlb_total_pages(void) |
230 | { |
231 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); |
232 | } |
233 | EXPORT_SYMBOL(hugetlb_total_pages); |
234 | |
235 | /* |
236 | * We cannot handle pagefaults against hugetlb pages at all. They cause |
237 | * handle_mm_fault() to try to instantiate regular-sized pages in the |
238 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get |
239 | * this far. |
240 | */ |
241 | static struct page *hugetlb_nopage(struct vm_area_struct *vma, |
242 | unsigned long address, int *unused) |
243 | { |
244 | BUG(); |
245 | return NULL; |
246 | } |
247 | |
248 | struct vm_operations_struct hugetlb_vm_ops = { |
249 | .nopage = hugetlb_nopage, |
250 | }; |
251 | |
252 | void zap_hugepage_range(struct vm_area_struct *vma, |
253 | unsigned long start, unsigned long length) |
254 | { |
255 | struct mm_struct *mm = vma->vm_mm; |
256 | |
257 | spin_lock(&mm->page_table_lock); |
258 | unmap_hugepage_range(vma, start, start + length); |
259 | spin_unlock(&mm->page_table_lock); |
260 | } |