Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | #include <linux/sysctl.h> |
| 11 | #include <linux/highmem.h> |
| 12 | #include <linux/nodemask.h> |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 13 | #include <linux/pagemap.h> |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 14 | #include <linux/mempolicy.h> |
Christoph Lameter | aea47ff | 2006-01-08 01:00:57 -0800 | [diff] [blame] | 15 | #include <linux/cpuset.h> |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 16 | #include <linux/mutex.h> |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 17 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 18 | #include <asm/page.h> |
| 19 | #include <asm/pgtable.h> |
| 20 | |
| 21 | #include <linux/hugetlb.h> |
Nick Piggin | 7835e98 | 2006-03-22 00:08:40 -0800 | [diff] [blame] | 22 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | |
| 24 | const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 25 | static unsigned long nr_huge_pages, free_huge_pages, resv_huge_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | unsigned long max_huge_pages; |
| 27 | static struct list_head hugepage_freelists[MAX_NUMNODES]; |
| 28 | static unsigned int nr_huge_pages_node[MAX_NUMNODES]; |
| 29 | static unsigned int free_huge_pages_node[MAX_NUMNODES]; |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 30 | static gfp_t htlb_alloc_mask = GFP_HIGHUSER; |
| 31 | unsigned long hugepages_treat_as_movable; |
| 32 | |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 33 | /* |
| 34 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages |
| 35 | */ |
| 36 | static DEFINE_SPINLOCK(hugetlb_lock); |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 37 | |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 38 | static void clear_huge_page(struct page *page, unsigned long addr) |
| 39 | { |
| 40 | int i; |
| 41 | |
| 42 | might_sleep(); |
| 43 | for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) { |
| 44 | cond_resched(); |
Ralf Baechle | 281e0e3 | 2007-10-01 01:20:10 -0700 | [diff] [blame] | 45 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 46 | } |
| 47 | } |
| 48 | |
| 49 | static void copy_huge_page(struct page *dst, struct page *src, |
Atsushi Nemoto | 9de455b | 2006-12-12 17:14:55 +0000 | [diff] [blame] | 50 | unsigned long addr, struct vm_area_struct *vma) |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 51 | { |
| 52 | int i; |
| 53 | |
| 54 | might_sleep(); |
| 55 | for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) { |
| 56 | cond_resched(); |
Atsushi Nemoto | 9de455b | 2006-12-12 17:14:55 +0000 | [diff] [blame] | 57 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 58 | } |
| 59 | } |
| 60 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | static void enqueue_huge_page(struct page *page) |
| 62 | { |
| 63 | int nid = page_to_nid(page); |
| 64 | list_add(&page->lru, &hugepage_freelists[nid]); |
| 65 | free_huge_pages++; |
| 66 | free_huge_pages_node[nid]++; |
| 67 | } |
| 68 | |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 69 | static struct page *dequeue_huge_page(struct vm_area_struct *vma, |
| 70 | unsigned long address) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | { |
Nishanth Aravamudan | 31a5c6e | 2007-07-15 23:38:02 -0700 | [diff] [blame] | 72 | int nid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | struct page *page = NULL; |
Lee Schermerhorn | 480eccf | 2007-09-18 22:46:47 -0700 | [diff] [blame] | 74 | struct mempolicy *mpol; |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 75 | struct zonelist *zonelist = huge_zonelist(vma, address, |
Lee Schermerhorn | 480eccf | 2007-09-18 22:46:47 -0700 | [diff] [blame] | 76 | htlb_alloc_mask, &mpol); |
Christoph Lameter | 96df933 | 2006-01-06 00:10:45 -0800 | [diff] [blame] | 77 | struct zone **z; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | |
Christoph Lameter | 96df933 | 2006-01-06 00:10:45 -0800 | [diff] [blame] | 79 | for (z = zonelist->zones; *z; z++) { |
Christoph Lameter | 89fa302 | 2006-09-25 23:31:55 -0700 | [diff] [blame] | 80 | nid = zone_to_nid(*z); |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 81 | if (cpuset_zone_allowed_softwall(*z, htlb_alloc_mask) && |
Andrew Morton | 3abf7af | 2007-07-19 01:49:08 -0700 | [diff] [blame] | 82 | !list_empty(&hugepage_freelists[nid])) { |
| 83 | page = list_entry(hugepage_freelists[nid].next, |
| 84 | struct page, lru); |
| 85 | list_del(&page->lru); |
| 86 | free_huge_pages--; |
| 87 | free_huge_pages_node[nid]--; |
Ken Chen | 5ab3ee7 | 2007-07-23 18:44:00 -0700 | [diff] [blame] | 88 | break; |
Andrew Morton | 3abf7af | 2007-07-19 01:49:08 -0700 | [diff] [blame] | 89 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | } |
Lee Schermerhorn | 480eccf | 2007-09-18 22:46:47 -0700 | [diff] [blame] | 91 | mpol_free(mpol); /* unref if mpol !NULL */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | return page; |
| 93 | } |
| 94 | |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 95 | static void free_huge_page(struct page *page) |
| 96 | { |
| 97 | BUG_ON(page_count(page)); |
| 98 | |
| 99 | INIT_LIST_HEAD(&page->lru); |
| 100 | |
| 101 | spin_lock(&hugetlb_lock); |
| 102 | enqueue_huge_page(page); |
| 103 | spin_unlock(&hugetlb_lock); |
| 104 | } |
| 105 | |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 106 | static int alloc_fresh_huge_page(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | { |
Joe Jin | f96efd5 | 2007-07-15 23:38:12 -0700 | [diff] [blame] | 108 | static int prev_nid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | struct page *page; |
Joe Jin | f96efd5 | 2007-07-15 23:38:12 -0700 | [diff] [blame] | 110 | int nid; |
| 111 | |
Hugh Dickins | 7ed5cb2 | 2007-07-19 01:49:11 -0700 | [diff] [blame] | 112 | /* |
| 113 | * Copy static prev_nid to local nid, work on that, then copy it |
| 114 | * back to prev_nid afterwards: otherwise there's a window in which |
| 115 | * a racer might pass invalid nid MAX_NUMNODES to alloc_pages_node. |
| 116 | * But we don't need to use a spin_lock here: it really doesn't |
| 117 | * matter if occasionally a racer chooses the same nid as we do. |
| 118 | */ |
Joe Jin | f96efd5 | 2007-07-15 23:38:12 -0700 | [diff] [blame] | 119 | nid = next_node(prev_nid, node_online_map); |
Paul Jackson | fdb7cc5 | 2006-03-22 00:09:10 -0800 | [diff] [blame] | 120 | if (nid == MAX_NUMNODES) |
| 121 | nid = first_node(node_online_map); |
Joe Jin | f96efd5 | 2007-07-15 23:38:12 -0700 | [diff] [blame] | 122 | prev_nid = nid; |
Joe Jin | f96efd5 | 2007-07-15 23:38:12 -0700 | [diff] [blame] | 123 | |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 124 | page = alloc_pages_node(nid, htlb_alloc_mask|__GFP_COMP|__GFP_NOWARN, |
Joe Jin | f96efd5 | 2007-07-15 23:38:12 -0700 | [diff] [blame] | 125 | HUGETLB_PAGE_ORDER); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | if (page) { |
Andy Whitcroft | 33f2ef8 | 2006-12-06 20:33:32 -0800 | [diff] [blame] | 127 | set_compound_page_dtor(page, free_huge_page); |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 128 | spin_lock(&hugetlb_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | nr_huge_pages++; |
| 130 | nr_huge_pages_node[page_to_nid(page)]++; |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 131 | spin_unlock(&hugetlb_lock); |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 132 | put_page(page); /* free it into the hugepage allocator */ |
| 133 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | } |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 135 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | } |
| 137 | |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 138 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
| 139 | unsigned long addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | { |
| 141 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | |
| 143 | spin_lock(&hugetlb_lock); |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 144 | if (vma->vm_flags & VM_MAYSHARE) |
| 145 | resv_huge_pages--; |
| 146 | else if (free_huge_pages <= resv_huge_pages) |
| 147 | goto fail; |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 148 | |
| 149 | page = dequeue_huge_page(vma, addr); |
| 150 | if (!page) |
| 151 | goto fail; |
| 152 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | spin_unlock(&hugetlb_lock); |
Nick Piggin | 7835e98 | 2006-03-22 00:08:40 -0800 | [diff] [blame] | 154 | set_page_refcounted(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | return page; |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 156 | |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 157 | fail: |
Ken Chen | ace4bd2 | 2007-05-09 02:33:09 -0700 | [diff] [blame] | 158 | if (vma->vm_flags & VM_MAYSHARE) |
| 159 | resv_huge_pages++; |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 160 | spin_unlock(&hugetlb_lock); |
| 161 | return NULL; |
| 162 | } |
| 163 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | static int __init hugetlb_init(void) |
| 165 | { |
| 166 | unsigned long i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | |
Benjamin Herrenschmidt | 3c726f8 | 2005-11-07 11:06:55 +1100 | [diff] [blame] | 168 | if (HPAGE_SHIFT == 0) |
| 169 | return 0; |
| 170 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | for (i = 0; i < MAX_NUMNODES; ++i) |
| 172 | INIT_LIST_HEAD(&hugepage_freelists[i]); |
| 173 | |
| 174 | for (i = 0; i < max_huge_pages; ++i) { |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 175 | if (!alloc_fresh_huge_page()) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | } |
| 178 | max_huge_pages = free_huge_pages = nr_huge_pages = i; |
| 179 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); |
| 180 | return 0; |
| 181 | } |
| 182 | module_init(hugetlb_init); |
| 183 | |
| 184 | static int __init hugetlb_setup(char *s) |
| 185 | { |
| 186 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) |
| 187 | max_huge_pages = 0; |
| 188 | return 1; |
| 189 | } |
| 190 | __setup("hugepages=", hugetlb_setup); |
| 191 | |
Ken Chen | 8a63011 | 2007-05-09 02:33:34 -0700 | [diff] [blame] | 192 | static unsigned int cpuset_mems_nr(unsigned int *array) |
| 193 | { |
| 194 | int node; |
| 195 | unsigned int nr = 0; |
| 196 | |
| 197 | for_each_node_mask(node, cpuset_current_mems_allowed) |
| 198 | nr += array[node]; |
| 199 | |
| 200 | return nr; |
| 201 | } |
| 202 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | #ifdef CONFIG_SYSCTL |
| 204 | static void update_and_free_page(struct page *page) |
| 205 | { |
| 206 | int i; |
| 207 | nr_huge_pages--; |
Christoph Lameter | 4415cc8 | 2006-09-25 23:31:55 -0700 | [diff] [blame] | 208 | nr_huge_pages_node[page_to_nid(page)]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 209 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { |
| 210 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | |
| 211 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | |
| 212 | 1 << PG_private | 1<< PG_writeback); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | } |
Akinobu Mita | f8af0bb | 2007-07-19 01:49:12 -0700 | [diff] [blame] | 214 | set_compound_page_dtor(page, NULL); |
Nick Piggin | 7835e98 | 2006-03-22 00:08:40 -0800 | [diff] [blame] | 215 | set_page_refcounted(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | __free_pages(page, HUGETLB_PAGE_ORDER); |
| 217 | } |
| 218 | |
| 219 | #ifdef CONFIG_HIGHMEM |
| 220 | static void try_to_free_low(unsigned long count) |
| 221 | { |
Christoph Lameter | 4415cc8 | 2006-09-25 23:31:55 -0700 | [diff] [blame] | 222 | int i; |
| 223 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | for (i = 0; i < MAX_NUMNODES; ++i) { |
| 225 | struct page *page, *next; |
| 226 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { |
| 227 | if (PageHighMem(page)) |
| 228 | continue; |
| 229 | list_del(&page->lru); |
| 230 | update_and_free_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 231 | free_huge_pages--; |
Christoph Lameter | 4415cc8 | 2006-09-25 23:31:55 -0700 | [diff] [blame] | 232 | free_huge_pages_node[page_to_nid(page)]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | if (count >= nr_huge_pages) |
| 234 | return; |
| 235 | } |
| 236 | } |
| 237 | } |
| 238 | #else |
| 239 | static inline void try_to_free_low(unsigned long count) |
| 240 | { |
| 241 | } |
| 242 | #endif |
| 243 | |
| 244 | static unsigned long set_max_huge_pages(unsigned long count) |
| 245 | { |
| 246 | while (count > nr_huge_pages) { |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 247 | if (!alloc_fresh_huge_page()) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 248 | return nr_huge_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | } |
| 250 | if (count >= nr_huge_pages) |
| 251 | return nr_huge_pages; |
| 252 | |
| 253 | spin_lock(&hugetlb_lock); |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 254 | count = max(count, resv_huge_pages); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 255 | try_to_free_low(count); |
| 256 | while (count < nr_huge_pages) { |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 257 | struct page *page = dequeue_huge_page(NULL, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | if (!page) |
| 259 | break; |
| 260 | update_and_free_page(page); |
| 261 | } |
| 262 | spin_unlock(&hugetlb_lock); |
| 263 | return nr_huge_pages; |
| 264 | } |
| 265 | |
| 266 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
| 267 | struct file *file, void __user *buffer, |
| 268 | size_t *length, loff_t *ppos) |
| 269 | { |
| 270 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
| 271 | max_huge_pages = set_max_huge_pages(max_huge_pages); |
| 272 | return 0; |
| 273 | } |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 274 | |
| 275 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, |
| 276 | struct file *file, void __user *buffer, |
| 277 | size_t *length, loff_t *ppos) |
| 278 | { |
| 279 | proc_dointvec(table, write, file, buffer, length, ppos); |
| 280 | if (hugepages_treat_as_movable) |
| 281 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; |
| 282 | else |
| 283 | htlb_alloc_mask = GFP_HIGHUSER; |
| 284 | return 0; |
| 285 | } |
| 286 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | #endif /* CONFIG_SYSCTL */ |
| 288 | |
| 289 | int hugetlb_report_meminfo(char *buf) |
| 290 | { |
| 291 | return sprintf(buf, |
| 292 | "HugePages_Total: %5lu\n" |
| 293 | "HugePages_Free: %5lu\n" |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 294 | "HugePages_Rsvd: %5lu\n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 295 | "Hugepagesize: %5lu kB\n", |
| 296 | nr_huge_pages, |
| 297 | free_huge_pages, |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 298 | resv_huge_pages, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 299 | HPAGE_SIZE/1024); |
| 300 | } |
| 301 | |
| 302 | int hugetlb_report_node_meminfo(int nid, char *buf) |
| 303 | { |
| 304 | return sprintf(buf, |
| 305 | "Node %d HugePages_Total: %5u\n" |
| 306 | "Node %d HugePages_Free: %5u\n", |
| 307 | nid, nr_huge_pages_node[nid], |
| 308 | nid, free_huge_pages_node[nid]); |
| 309 | } |
| 310 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
| 312 | unsigned long hugetlb_total_pages(void) |
| 313 | { |
| 314 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); |
| 315 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 316 | |
| 317 | /* |
| 318 | * We cannot handle pagefaults against hugetlb pages at all. They cause |
| 319 | * handle_mm_fault() to try to instantiate regular-sized pages in the |
| 320 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get |
| 321 | * this far. |
| 322 | */ |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 323 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 324 | { |
| 325 | BUG(); |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 326 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | } |
| 328 | |
| 329 | struct vm_operations_struct hugetlb_vm_ops = { |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 330 | .fault = hugetlb_vm_op_fault, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 331 | }; |
| 332 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 333 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
| 334 | int writable) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 335 | { |
| 336 | pte_t entry; |
| 337 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 338 | if (writable) { |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 339 | entry = |
| 340 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); |
| 341 | } else { |
| 342 | entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); |
| 343 | } |
| 344 | entry = pte_mkyoung(entry); |
| 345 | entry = pte_mkhuge(entry); |
| 346 | |
| 347 | return entry; |
| 348 | } |
| 349 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 350 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
| 351 | unsigned long address, pte_t *ptep) |
| 352 | { |
| 353 | pte_t entry; |
| 354 | |
| 355 | entry = pte_mkwrite(pte_mkdirty(*ptep)); |
Benjamin Herrenschmidt | 8dab524 | 2007-06-16 10:16:12 -0700 | [diff] [blame] | 356 | if (ptep_set_access_flags(vma, address, ptep, entry, 1)) { |
| 357 | update_mmu_cache(vma, address, entry); |
Benjamin Herrenschmidt | 8dab524 | 2007-06-16 10:16:12 -0700 | [diff] [blame] | 358 | } |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 359 | } |
| 360 | |
| 361 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 362 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
| 363 | struct vm_area_struct *vma) |
| 364 | { |
| 365 | pte_t *src_pte, *dst_pte, entry; |
| 366 | struct page *ptepage; |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 367 | unsigned long addr; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 368 | int cow; |
| 369 | |
| 370 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 371 | |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 372 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 373 | src_pte = huge_pte_offset(src, addr); |
| 374 | if (!src_pte) |
| 375 | continue; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 376 | dst_pte = huge_pte_alloc(dst, addr); |
| 377 | if (!dst_pte) |
| 378 | goto nomem; |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 379 | spin_lock(&dst->page_table_lock); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 380 | spin_lock(&src->page_table_lock); |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 381 | if (!pte_none(*src_pte)) { |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 382 | if (cow) |
| 383 | ptep_set_wrprotect(src, addr, src_pte); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 384 | entry = *src_pte; |
| 385 | ptepage = pte_page(entry); |
| 386 | get_page(ptepage); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 387 | set_huge_pte_at(dst, addr, dst_pte, entry); |
| 388 | } |
| 389 | spin_unlock(&src->page_table_lock); |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 390 | spin_unlock(&dst->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 391 | } |
| 392 | return 0; |
| 393 | |
| 394 | nomem: |
| 395 | return -ENOMEM; |
| 396 | } |
| 397 | |
Chen, Kenneth W | 502717f | 2006-10-11 01:20:46 -0700 | [diff] [blame] | 398 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
| 399 | unsigned long end) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 400 | { |
| 401 | struct mm_struct *mm = vma->vm_mm; |
| 402 | unsigned long address; |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 403 | pte_t *ptep; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 404 | pte_t pte; |
| 405 | struct page *page; |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 406 | struct page *tmp; |
Chen, Kenneth W | c0a499c | 2006-12-06 20:31:39 -0800 | [diff] [blame] | 407 | /* |
| 408 | * A page gathering list, protected by per file i_mmap_lock. The |
| 409 | * lock is used to avoid list corruption from multiple unmapping |
| 410 | * of the same page since we are using page->lru. |
| 411 | */ |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 412 | LIST_HEAD(page_list); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 413 | |
| 414 | WARN_ON(!is_vm_hugetlb_page(vma)); |
| 415 | BUG_ON(start & ~HPAGE_MASK); |
| 416 | BUG_ON(end & ~HPAGE_MASK); |
| 417 | |
Hugh Dickins | 508034a | 2005-10-29 18:16:30 -0700 | [diff] [blame] | 418 | spin_lock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 419 | for (address = start; address < end; address += HPAGE_SIZE) { |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 420 | ptep = huge_pte_offset(mm, address); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 421 | if (!ptep) |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 422 | continue; |
| 423 | |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 424 | if (huge_pmd_unshare(mm, &address, ptep)) |
| 425 | continue; |
| 426 | |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 427 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 428 | if (pte_none(pte)) |
| 429 | continue; |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 430 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 431 | page = pte_page(pte); |
Ken Chen | 6649a38 | 2007-02-08 14:20:27 -0800 | [diff] [blame] | 432 | if (pte_dirty(pte)) |
| 433 | set_page_dirty(page); |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 434 | list_add(&page->lru, &page_list); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 435 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | spin_unlock(&mm->page_table_lock); |
Hugh Dickins | 508034a | 2005-10-29 18:16:30 -0700 | [diff] [blame] | 437 | flush_tlb_range(vma, start, end); |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 438 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
| 439 | list_del(&page->lru); |
| 440 | put_page(page); |
| 441 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 443 | |
Chen, Kenneth W | 502717f | 2006-10-11 01:20:46 -0700 | [diff] [blame] | 444 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
| 445 | unsigned long end) |
| 446 | { |
| 447 | /* |
| 448 | * It is undesirable to test vma->vm_file as it should be non-null |
| 449 | * for valid hugetlb area. However, vm_file will be NULL in the error |
| 450 | * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, |
| 451 | * do_mmap_pgoff() nullifies vma->vm_file before calling this function |
| 452 | * to clean up. Since no pte has actually been setup, it is safe to |
| 453 | * do nothing in this case. |
| 454 | */ |
| 455 | if (vma->vm_file) { |
| 456 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
| 457 | __unmap_hugepage_range(vma, start, end); |
| 458 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
| 459 | } |
| 460 | } |
| 461 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 462 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
| 463 | unsigned long address, pte_t *ptep, pte_t pte) |
| 464 | { |
| 465 | struct page *old_page, *new_page; |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 466 | int avoidcopy; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 467 | |
| 468 | old_page = pte_page(pte); |
| 469 | |
| 470 | /* If no-one else is actually using this page, avoid the copy |
| 471 | * and just make the page writable */ |
| 472 | avoidcopy = (page_count(old_page) == 1); |
| 473 | if (avoidcopy) { |
| 474 | set_huge_ptep_writable(vma, address, ptep); |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 475 | return 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 476 | } |
| 477 | |
| 478 | page_cache_get(old_page); |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 479 | new_page = alloc_huge_page(vma, address); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 480 | |
| 481 | if (!new_page) { |
| 482 | page_cache_release(old_page); |
Christoph Lameter | 0df420d | 2006-02-07 12:58:30 -0800 | [diff] [blame] | 483 | return VM_FAULT_OOM; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 484 | } |
| 485 | |
| 486 | spin_unlock(&mm->page_table_lock); |
Atsushi Nemoto | 9de455b | 2006-12-12 17:14:55 +0000 | [diff] [blame] | 487 | copy_huge_page(new_page, old_page, address, vma); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 488 | spin_lock(&mm->page_table_lock); |
| 489 | |
| 490 | ptep = huge_pte_offset(mm, address & HPAGE_MASK); |
| 491 | if (likely(pte_same(*ptep, pte))) { |
| 492 | /* Break COW */ |
| 493 | set_huge_pte_at(mm, address, ptep, |
| 494 | make_huge_pte(vma, new_page, 1)); |
| 495 | /* Make the old page be freed below */ |
| 496 | new_page = old_page; |
| 497 | } |
| 498 | page_cache_release(new_page); |
| 499 | page_cache_release(old_page); |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 500 | return 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 501 | } |
| 502 | |
Robert P. J. Day | a1ed3dd | 2007-07-17 04:03:33 -0700 | [diff] [blame] | 503 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 504 | unsigned long address, pte_t *ptep, int write_access) |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 505 | { |
| 506 | int ret = VM_FAULT_SIGBUS; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 507 | unsigned long idx; |
| 508 | unsigned long size; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 509 | struct page *page; |
| 510 | struct address_space *mapping; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 511 | pte_t new_pte; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 512 | |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 513 | mapping = vma->vm_file->f_mapping; |
| 514 | idx = ((address - vma->vm_start) >> HPAGE_SHIFT) |
| 515 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); |
| 516 | |
| 517 | /* |
| 518 | * Use page lock to guard against racing truncation |
| 519 | * before we get page_table_lock. |
| 520 | */ |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 521 | retry: |
| 522 | page = find_lock_page(mapping, idx); |
| 523 | if (!page) { |
Hugh Dickins | ebed4bf | 2006-10-28 10:38:43 -0700 | [diff] [blame] | 524 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
| 525 | if (idx >= size) |
| 526 | goto out; |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 527 | if (hugetlb_get_quota(mapping)) |
| 528 | goto out; |
| 529 | page = alloc_huge_page(vma, address); |
| 530 | if (!page) { |
| 531 | hugetlb_put_quota(mapping); |
Christoph Lameter | 0df420d | 2006-02-07 12:58:30 -0800 | [diff] [blame] | 532 | ret = VM_FAULT_OOM; |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 533 | goto out; |
| 534 | } |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 535 | clear_huge_page(page, address); |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 536 | |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 537 | if (vma->vm_flags & VM_SHARED) { |
| 538 | int err; |
| 539 | |
| 540 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); |
| 541 | if (err) { |
| 542 | put_page(page); |
| 543 | hugetlb_put_quota(mapping); |
| 544 | if (err == -EEXIST) |
| 545 | goto retry; |
| 546 | goto out; |
| 547 | } |
| 548 | } else |
| 549 | lock_page(page); |
| 550 | } |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 551 | |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 552 | spin_lock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 553 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
| 554 | if (idx >= size) |
| 555 | goto backout; |
| 556 | |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 557 | ret = 0; |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 558 | if (!pte_none(*ptep)) |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 559 | goto backout; |
| 560 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 561 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
| 562 | && (vma->vm_flags & VM_SHARED))); |
| 563 | set_huge_pte_at(mm, address, ptep, new_pte); |
| 564 | |
| 565 | if (write_access && !(vma->vm_flags & VM_SHARED)) { |
| 566 | /* Optimization, do the COW without a second fault */ |
| 567 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte); |
| 568 | } |
| 569 | |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 570 | spin_unlock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 571 | unlock_page(page); |
| 572 | out: |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 573 | return ret; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 574 | |
| 575 | backout: |
| 576 | spin_unlock(&mm->page_table_lock); |
| 577 | hugetlb_put_quota(mapping); |
| 578 | unlock_page(page); |
| 579 | put_page(page); |
| 580 | goto out; |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 581 | } |
| 582 | |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 583 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
| 584 | unsigned long address, int write_access) |
| 585 | { |
| 586 | pte_t *ptep; |
| 587 | pte_t entry; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 588 | int ret; |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 589 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 590 | |
| 591 | ptep = huge_pte_alloc(mm, address); |
| 592 | if (!ptep) |
| 593 | return VM_FAULT_OOM; |
| 594 | |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 595 | /* |
| 596 | * Serialize hugepage allocation and instantiation, so that we don't |
| 597 | * get spurious allocation failures if two CPUs race to instantiate |
| 598 | * the same page in the page cache. |
| 599 | */ |
| 600 | mutex_lock(&hugetlb_instantiation_mutex); |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 601 | entry = *ptep; |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 602 | if (pte_none(entry)) { |
| 603 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); |
| 604 | mutex_unlock(&hugetlb_instantiation_mutex); |
| 605 | return ret; |
| 606 | } |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 607 | |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 608 | ret = 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 609 | |
| 610 | spin_lock(&mm->page_table_lock); |
| 611 | /* Check for a racing update before calling hugetlb_cow */ |
| 612 | if (likely(pte_same(entry, *ptep))) |
| 613 | if (write_access && !pte_write(entry)) |
| 614 | ret = hugetlb_cow(mm, vma, address, ptep, entry); |
| 615 | spin_unlock(&mm->page_table_lock); |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 616 | mutex_unlock(&hugetlb_instantiation_mutex); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 617 | |
| 618 | return ret; |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 619 | } |
| 620 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 621 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
| 622 | struct page **pages, struct vm_area_struct **vmas, |
| 623 | unsigned long *position, int *length, int i) |
| 624 | { |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 625 | unsigned long pfn_offset; |
| 626 | unsigned long vaddr = *position; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 627 | int remainder = *length; |
| 628 | |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 629 | spin_lock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 630 | while (vaddr < vma->vm_end && remainder) { |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 631 | pte_t *pte; |
| 632 | struct page *page; |
| 633 | |
| 634 | /* |
| 635 | * Some archs (sparc64, sh*) have multiple pte_ts to |
| 636 | * each hugepage. We have to make * sure we get the |
| 637 | * first, for the page indexing below to work. |
| 638 | */ |
| 639 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); |
| 640 | |
| 641 | if (!pte || pte_none(*pte)) { |
| 642 | int ret; |
| 643 | |
| 644 | spin_unlock(&mm->page_table_lock); |
| 645 | ret = hugetlb_fault(mm, vma, vaddr, 0); |
| 646 | spin_lock(&mm->page_table_lock); |
Adam Litke | a89182c | 2007-08-22 14:01:51 -0700 | [diff] [blame] | 647 | if (!(ret & VM_FAULT_ERROR)) |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 648 | continue; |
| 649 | |
| 650 | remainder = 0; |
| 651 | if (!i) |
| 652 | i = -EFAULT; |
| 653 | break; |
| 654 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 655 | |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 656 | pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT; |
| 657 | page = pte_page(*pte); |
| 658 | same_page: |
Chen, Kenneth W | d669218 | 2006-03-31 02:29:57 -0800 | [diff] [blame] | 659 | if (pages) { |
| 660 | get_page(page); |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 661 | pages[i] = page + pfn_offset; |
Chen, Kenneth W | d669218 | 2006-03-31 02:29:57 -0800 | [diff] [blame] | 662 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 663 | |
| 664 | if (vmas) |
| 665 | vmas[i] = vma; |
| 666 | |
| 667 | vaddr += PAGE_SIZE; |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 668 | ++pfn_offset; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 669 | --remainder; |
| 670 | ++i; |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 671 | if (vaddr < vma->vm_end && remainder && |
| 672 | pfn_offset < HPAGE_SIZE/PAGE_SIZE) { |
| 673 | /* |
| 674 | * We use pfn_offset to avoid touching the pageframes |
| 675 | * of this compound page. |
| 676 | */ |
| 677 | goto same_page; |
| 678 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 679 | } |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 680 | spin_unlock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 681 | *length = remainder; |
| 682 | *position = vaddr; |
| 683 | |
| 684 | return i; |
| 685 | } |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 686 | |
| 687 | void hugetlb_change_protection(struct vm_area_struct *vma, |
| 688 | unsigned long address, unsigned long end, pgprot_t newprot) |
| 689 | { |
| 690 | struct mm_struct *mm = vma->vm_mm; |
| 691 | unsigned long start = address; |
| 692 | pte_t *ptep; |
| 693 | pte_t pte; |
| 694 | |
| 695 | BUG_ON(address >= end); |
| 696 | flush_cache_range(vma, address, end); |
| 697 | |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 698 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 699 | spin_lock(&mm->page_table_lock); |
| 700 | for (; address < end; address += HPAGE_SIZE) { |
| 701 | ptep = huge_pte_offset(mm, address); |
| 702 | if (!ptep) |
| 703 | continue; |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 704 | if (huge_pmd_unshare(mm, &address, ptep)) |
| 705 | continue; |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 706 | if (!pte_none(*ptep)) { |
| 707 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
| 708 | pte = pte_mkhuge(pte_modify(pte, newprot)); |
| 709 | set_huge_pte_at(mm, address, ptep, pte); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 710 | } |
| 711 | } |
| 712 | spin_unlock(&mm->page_table_lock); |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 713 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 714 | |
| 715 | flush_tlb_range(vma, start, end); |
| 716 | } |
| 717 | |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 718 | struct file_region { |
| 719 | struct list_head link; |
| 720 | long from; |
| 721 | long to; |
| 722 | }; |
| 723 | |
| 724 | static long region_add(struct list_head *head, long f, long t) |
| 725 | { |
| 726 | struct file_region *rg, *nrg, *trg; |
| 727 | |
| 728 | /* Locate the region we are either in or before. */ |
| 729 | list_for_each_entry(rg, head, link) |
| 730 | if (f <= rg->to) |
| 731 | break; |
| 732 | |
| 733 | /* Round our left edge to the current segment if it encloses us. */ |
| 734 | if (f > rg->from) |
| 735 | f = rg->from; |
| 736 | |
| 737 | /* Check for and consume any regions we now overlap with. */ |
| 738 | nrg = rg; |
| 739 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { |
| 740 | if (&rg->link == head) |
| 741 | break; |
| 742 | if (rg->from > t) |
| 743 | break; |
| 744 | |
| 745 | /* If this area reaches higher then extend our area to |
| 746 | * include it completely. If this is not the first area |
| 747 | * which we intend to reuse, free it. */ |
| 748 | if (rg->to > t) |
| 749 | t = rg->to; |
| 750 | if (rg != nrg) { |
| 751 | list_del(&rg->link); |
| 752 | kfree(rg); |
| 753 | } |
| 754 | } |
| 755 | nrg->from = f; |
| 756 | nrg->to = t; |
| 757 | return 0; |
| 758 | } |
| 759 | |
| 760 | static long region_chg(struct list_head *head, long f, long t) |
| 761 | { |
| 762 | struct file_region *rg, *nrg; |
| 763 | long chg = 0; |
| 764 | |
| 765 | /* Locate the region we are before or in. */ |
| 766 | list_for_each_entry(rg, head, link) |
| 767 | if (f <= rg->to) |
| 768 | break; |
| 769 | |
| 770 | /* If we are below the current region then a new region is required. |
| 771 | * Subtle, allocate a new region at the position but make it zero |
| 772 | * size such that we can guarentee to record the reservation. */ |
| 773 | if (&rg->link == head || t < rg->from) { |
| 774 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); |
| 775 | if (nrg == 0) |
| 776 | return -ENOMEM; |
| 777 | nrg->from = f; |
| 778 | nrg->to = f; |
| 779 | INIT_LIST_HEAD(&nrg->link); |
| 780 | list_add(&nrg->link, rg->link.prev); |
| 781 | |
| 782 | return t - f; |
| 783 | } |
| 784 | |
| 785 | /* Round our left edge to the current segment if it encloses us. */ |
| 786 | if (f > rg->from) |
| 787 | f = rg->from; |
| 788 | chg = t - f; |
| 789 | |
| 790 | /* Check for and consume any regions we now overlap with. */ |
| 791 | list_for_each_entry(rg, rg->link.prev, link) { |
| 792 | if (&rg->link == head) |
| 793 | break; |
| 794 | if (rg->from > t) |
| 795 | return chg; |
| 796 | |
| 797 | /* We overlap with this area, if it extends futher than |
| 798 | * us then we must extend ourselves. Account for its |
| 799 | * existing reservation. */ |
| 800 | if (rg->to > t) { |
| 801 | chg += rg->to - t; |
| 802 | t = rg->to; |
| 803 | } |
| 804 | chg -= rg->to - rg->from; |
| 805 | } |
| 806 | return chg; |
| 807 | } |
| 808 | |
| 809 | static long region_truncate(struct list_head *head, long end) |
| 810 | { |
| 811 | struct file_region *rg, *trg; |
| 812 | long chg = 0; |
| 813 | |
| 814 | /* Locate the region we are either in or before. */ |
| 815 | list_for_each_entry(rg, head, link) |
| 816 | if (end <= rg->to) |
| 817 | break; |
| 818 | if (&rg->link == head) |
| 819 | return 0; |
| 820 | |
| 821 | /* If we are in the middle of a region then adjust it. */ |
| 822 | if (end > rg->from) { |
| 823 | chg = rg->to - end; |
| 824 | rg->to = end; |
| 825 | rg = list_entry(rg->link.next, typeof(*rg), link); |
| 826 | } |
| 827 | |
| 828 | /* Drop any remaining regions. */ |
| 829 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { |
| 830 | if (&rg->link == head) |
| 831 | break; |
| 832 | chg += rg->to - rg->from; |
| 833 | list_del(&rg->link); |
| 834 | kfree(rg); |
| 835 | } |
| 836 | return chg; |
| 837 | } |
| 838 | |
| 839 | static int hugetlb_acct_memory(long delta) |
| 840 | { |
| 841 | int ret = -ENOMEM; |
| 842 | |
| 843 | spin_lock(&hugetlb_lock); |
| 844 | if ((delta + resv_huge_pages) <= free_huge_pages) { |
| 845 | resv_huge_pages += delta; |
| 846 | ret = 0; |
| 847 | } |
| 848 | spin_unlock(&hugetlb_lock); |
| 849 | return ret; |
| 850 | } |
| 851 | |
| 852 | int hugetlb_reserve_pages(struct inode *inode, long from, long to) |
| 853 | { |
| 854 | long ret, chg; |
| 855 | |
| 856 | chg = region_chg(&inode->i_mapping->private_list, from, to); |
| 857 | if (chg < 0) |
| 858 | return chg; |
Ken Chen | 8a63011 | 2007-05-09 02:33:34 -0700 | [diff] [blame] | 859 | /* |
| 860 | * When cpuset is configured, it breaks the strict hugetlb page |
| 861 | * reservation as the accounting is done on a global variable. Such |
| 862 | * reservation is completely rubbish in the presence of cpuset because |
| 863 | * the reservation is not checked against page availability for the |
| 864 | * current cpuset. Application can still potentially OOM'ed by kernel |
| 865 | * with lack of free htlb page in cpuset that the task is in. |
| 866 | * Attempt to enforce strict accounting with cpuset is almost |
| 867 | * impossible (or too ugly) because cpuset is too fluid that |
| 868 | * task or memory node can be dynamically moved between cpusets. |
| 869 | * |
| 870 | * The change of semantics for shared hugetlb mapping with cpuset is |
| 871 | * undesirable. However, in order to preserve some of the semantics, |
| 872 | * we fall back to check against current free page availability as |
| 873 | * a best attempt and hopefully to minimize the impact of changing |
| 874 | * semantics that cpuset has. |
| 875 | */ |
| 876 | if (chg > cpuset_mems_nr(free_huge_pages_node)) |
| 877 | return -ENOMEM; |
| 878 | |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 879 | ret = hugetlb_acct_memory(chg); |
| 880 | if (ret < 0) |
| 881 | return ret; |
| 882 | region_add(&inode->i_mapping->private_list, from, to); |
| 883 | return 0; |
| 884 | } |
| 885 | |
| 886 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) |
| 887 | { |
| 888 | long chg = region_truncate(&inode->i_mapping->private_list, offset); |
| 889 | hugetlb_acct_memory(freed - chg); |
| 890 | } |