blob: 38633864a93e874009d9e6aa00619cf7471b0d9e [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/sysctl.h>
11#include <linux/highmem.h>
Andrea Arcangelicddb8a52008-07-28 15:46:29 -070012#include <linux/mmu_notifier.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/nodemask.h>
David Gibson63551ae2005-06-21 17:14:44 -070014#include <linux/pagemap.h>
Christoph Lameter5da7ca82006-01-06 00:10:46 -080015#include <linux/mempolicy.h>
Christoph Lameteraea47ff2006-01-08 01:00:57 -080016#include <linux/cpuset.h>
David Gibson3935baa2006-03-22 00:08:53 -080017#include <linux/mutex.h>
Andi Kleenaa888a72008-07-23 21:27:47 -070018#include <linux/bootmem.h>
Nishanth Aravamudana3437872008-07-23 21:27:44 -070019#include <linux/sysfs.h>
Linus Torvaldsd6606682008-08-06 12:04:54 -070020
David Gibson63551ae2005-06-21 17:14:44 -070021#include <asm/page.h>
22#include <asm/pgtable.h>
Adrian Bunk78a34ae2008-07-28 15:46:30 -070023#include <asm/io.h>
David Gibson63551ae2005-06-21 17:14:44 -070024
25#include <linux/hugetlb.h>
Nick Piggin7835e982006-03-22 00:08:40 -080026#include "internal.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
28const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
Mel Gorman396faf02007-07-17 04:03:13 -070029static gfp_t htlb_alloc_mask = GFP_HIGHUSER;
30unsigned long hugepages_treat_as_movable;
Andi Kleena5516432008-07-23 21:27:41 -070031
Andi Kleene5ff2152008-07-23 21:27:42 -070032static int max_hstate;
33unsigned int default_hstate_idx;
34struct hstate hstates[HUGE_MAX_HSTATE];
35
Jon Tollefson53ba51d2008-07-23 21:27:52 -070036__initdata LIST_HEAD(huge_boot_pages);
37
Andi Kleene5ff2152008-07-23 21:27:42 -070038/* for command line parsing */
39static struct hstate * __initdata parsed_hstate;
40static unsigned long __initdata default_hstate_max_huge_pages;
Nick Piggine11bfbf2008-07-23 21:27:52 -070041static unsigned long __initdata default_hstate_size;
Andi Kleene5ff2152008-07-23 21:27:42 -070042
43#define for_each_hstate(h) \
44 for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++)
Mel Gorman396faf02007-07-17 04:03:13 -070045
David Gibson3935baa2006-03-22 00:08:53 -080046/*
47 * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages
48 */
49static DEFINE_SPINLOCK(hugetlb_lock);
Eric Paris0bd0f9f2005-11-21 21:32:28 -080050
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -070051/*
Andy Whitcroft96822902008-07-23 21:27:29 -070052 * Region tracking -- allows tracking of reservations and instantiated pages
53 * across the pages in a mapping.
Andy Whitcroft84afd992008-07-23 21:27:32 -070054 *
55 * The region data structures are protected by a combination of the mmap_sem
56 * and the hugetlb_instantion_mutex. To access or modify a region the caller
57 * must either hold the mmap_sem for write, or the mmap_sem for read and
58 * the hugetlb_instantiation mutex:
59 *
60 * down_write(&mm->mmap_sem);
61 * or
62 * down_read(&mm->mmap_sem);
63 * mutex_lock(&hugetlb_instantiation_mutex);
Andy Whitcroft96822902008-07-23 21:27:29 -070064 */
65struct file_region {
66 struct list_head link;
67 long from;
68 long to;
69};
70
71static long region_add(struct list_head *head, long f, long t)
72{
73 struct file_region *rg, *nrg, *trg;
74
75 /* Locate the region we are either in or before. */
76 list_for_each_entry(rg, head, link)
77 if (f <= rg->to)
78 break;
79
80 /* Round our left edge to the current segment if it encloses us. */
81 if (f > rg->from)
82 f = rg->from;
83
84 /* Check for and consume any regions we now overlap with. */
85 nrg = rg;
86 list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
87 if (&rg->link == head)
88 break;
89 if (rg->from > t)
90 break;
91
92 /* If this area reaches higher then extend our area to
93 * include it completely. If this is not the first area
94 * which we intend to reuse, free it. */
95 if (rg->to > t)
96 t = rg->to;
97 if (rg != nrg) {
98 list_del(&rg->link);
99 kfree(rg);
100 }
101 }
102 nrg->from = f;
103 nrg->to = t;
104 return 0;
105}
106
107static long region_chg(struct list_head *head, long f, long t)
108{
109 struct file_region *rg, *nrg;
110 long chg = 0;
111
112 /* Locate the region we are before or in. */
113 list_for_each_entry(rg, head, link)
114 if (f <= rg->to)
115 break;
116
117 /* If we are below the current region then a new region is required.
118 * Subtle, allocate a new region at the position but make it zero
119 * size such that we can guarantee to record the reservation. */
120 if (&rg->link == head || t < rg->from) {
121 nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
122 if (!nrg)
123 return -ENOMEM;
124 nrg->from = f;
125 nrg->to = f;
126 INIT_LIST_HEAD(&nrg->link);
127 list_add(&nrg->link, rg->link.prev);
128
129 return t - f;
130 }
131
132 /* Round our left edge to the current segment if it encloses us. */
133 if (f > rg->from)
134 f = rg->from;
135 chg = t - f;
136
137 /* Check for and consume any regions we now overlap with. */
138 list_for_each_entry(rg, rg->link.prev, link) {
139 if (&rg->link == head)
140 break;
141 if (rg->from > t)
142 return chg;
143
144 /* We overlap with this area, if it extends futher than
145 * us then we must extend ourselves. Account for its
146 * existing reservation. */
147 if (rg->to > t) {
148 chg += rg->to - t;
149 t = rg->to;
150 }
151 chg -= rg->to - rg->from;
152 }
153 return chg;
154}
155
156static long region_truncate(struct list_head *head, long end)
157{
158 struct file_region *rg, *trg;
159 long chg = 0;
160
161 /* Locate the region we are either in or before. */
162 list_for_each_entry(rg, head, link)
163 if (end <= rg->to)
164 break;
165 if (&rg->link == head)
166 return 0;
167
168 /* If we are in the middle of a region then adjust it. */
169 if (end > rg->from) {
170 chg = rg->to - end;
171 rg->to = end;
172 rg = list_entry(rg->link.next, typeof(*rg), link);
173 }
174
175 /* Drop any remaining regions. */
176 list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
177 if (&rg->link == head)
178 break;
179 chg += rg->to - rg->from;
180 list_del(&rg->link);
181 kfree(rg);
182 }
183 return chg;
184}
185
Andy Whitcroft84afd992008-07-23 21:27:32 -0700186static long region_count(struct list_head *head, long f, long t)
187{
188 struct file_region *rg;
189 long chg = 0;
190
191 /* Locate each segment we overlap with, and count that overlap. */
192 list_for_each_entry(rg, head, link) {
193 int seg_from;
194 int seg_to;
195
196 if (rg->to <= f)
197 continue;
198 if (rg->from >= t)
199 break;
200
201 seg_from = max(rg->from, f);
202 seg_to = min(rg->to, t);
203
204 chg += seg_to - seg_from;
205 }
206
207 return chg;
208}
209
Andy Whitcroft96822902008-07-23 21:27:29 -0700210/*
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700211 * Convert the address within this vma to the page offset within
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700212 * the mapping, in pagecache page units; huge pages here.
213 */
Andi Kleena5516432008-07-23 21:27:41 -0700214static pgoff_t vma_hugecache_offset(struct hstate *h,
215 struct vm_area_struct *vma, unsigned long address)
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700216{
Andi Kleena5516432008-07-23 21:27:41 -0700217 return ((address - vma->vm_start) >> huge_page_shift(h)) +
218 (vma->vm_pgoff >> huge_page_order(h));
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700219}
220
Andy Whitcroft84afd992008-07-23 21:27:32 -0700221/*
222 * Flags for MAP_PRIVATE reservations. These are stored in the bottom
223 * bits of the reservation map pointer, which are always clear due to
224 * alignment.
225 */
226#define HPAGE_RESV_OWNER (1UL << 0)
227#define HPAGE_RESV_UNMAPPED (1UL << 1)
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700228#define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED)
Andy Whitcroft84afd992008-07-23 21:27:32 -0700229
Mel Gormana1e78772008-07-23 21:27:23 -0700230/*
231 * These helpers are used to track how many pages are reserved for
232 * faults in a MAP_PRIVATE mapping. Only the process that called mmap()
233 * is guaranteed to have their future faults succeed.
234 *
235 * With the exception of reset_vma_resv_huge_pages() which is called at fork(),
236 * the reserve counters are updated with the hugetlb_lock held. It is safe
237 * to reset the VMA at fork() time as it is not in use yet and there is no
238 * chance of the global counters getting corrupted as a result of the values.
Andy Whitcroft84afd992008-07-23 21:27:32 -0700239 *
240 * The private mapping reservation is represented in a subtly different
241 * manner to a shared mapping. A shared mapping has a region map associated
242 * with the underlying file, this region map represents the backing file
243 * pages which have ever had a reservation assigned which this persists even
244 * after the page is instantiated. A private mapping has a region map
245 * associated with the original mmap which is attached to all VMAs which
246 * reference it, this region map represents those offsets which have consumed
247 * reservation ie. where pages have been instantiated.
Mel Gormana1e78772008-07-23 21:27:23 -0700248 */
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700249static unsigned long get_vma_private_data(struct vm_area_struct *vma)
250{
251 return (unsigned long)vma->vm_private_data;
252}
253
254static void set_vma_private_data(struct vm_area_struct *vma,
255 unsigned long value)
256{
257 vma->vm_private_data = (void *)value;
258}
259
Andy Whitcroft84afd992008-07-23 21:27:32 -0700260struct resv_map {
261 struct kref refs;
262 struct list_head regions;
263};
264
265struct resv_map *resv_map_alloc(void)
266{
267 struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL);
268 if (!resv_map)
269 return NULL;
270
271 kref_init(&resv_map->refs);
272 INIT_LIST_HEAD(&resv_map->regions);
273
274 return resv_map;
275}
276
277void resv_map_release(struct kref *ref)
278{
279 struct resv_map *resv_map = container_of(ref, struct resv_map, refs);
280
281 /* Clear out any active regions before we release the map. */
282 region_truncate(&resv_map->regions, 0);
283 kfree(resv_map);
284}
285
286static struct resv_map *vma_resv_map(struct vm_area_struct *vma)
Mel Gormana1e78772008-07-23 21:27:23 -0700287{
288 VM_BUG_ON(!is_vm_hugetlb_page(vma));
289 if (!(vma->vm_flags & VM_SHARED))
Andy Whitcroft84afd992008-07-23 21:27:32 -0700290 return (struct resv_map *)(get_vma_private_data(vma) &
291 ~HPAGE_RESV_MASK);
Mel Gormana1e78772008-07-23 21:27:23 -0700292 return 0;
293}
294
Andy Whitcroft84afd992008-07-23 21:27:32 -0700295static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map)
Mel Gormana1e78772008-07-23 21:27:23 -0700296{
297 VM_BUG_ON(!is_vm_hugetlb_page(vma));
298 VM_BUG_ON(vma->vm_flags & VM_SHARED);
299
Andy Whitcroft84afd992008-07-23 21:27:32 -0700300 set_vma_private_data(vma, (get_vma_private_data(vma) &
301 HPAGE_RESV_MASK) | (unsigned long)map);
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700302}
303
304static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags)
305{
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700306 VM_BUG_ON(!is_vm_hugetlb_page(vma));
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700307 VM_BUG_ON(vma->vm_flags & VM_SHARED);
308
309 set_vma_private_data(vma, get_vma_private_data(vma) | flags);
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700310}
311
312static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag)
313{
314 VM_BUG_ON(!is_vm_hugetlb_page(vma));
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700315
316 return (get_vma_private_data(vma) & flag) != 0;
Mel Gormana1e78772008-07-23 21:27:23 -0700317}
318
319/* Decrement the reserved pages in the hugepage pool by one */
Andi Kleena5516432008-07-23 21:27:41 -0700320static void decrement_hugepage_resv_vma(struct hstate *h,
321 struct vm_area_struct *vma)
Mel Gormana1e78772008-07-23 21:27:23 -0700322{
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700323 if (vma->vm_flags & VM_NORESERVE)
324 return;
325
Mel Gormana1e78772008-07-23 21:27:23 -0700326 if (vma->vm_flags & VM_SHARED) {
327 /* Shared mappings always use reserves */
Andi Kleena5516432008-07-23 21:27:41 -0700328 h->resv_huge_pages--;
Andy Whitcroft84afd992008-07-23 21:27:32 -0700329 } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
Mel Gormana1e78772008-07-23 21:27:23 -0700330 /*
331 * Only the process that called mmap() has reserves for
332 * private mappings.
333 */
Andi Kleena5516432008-07-23 21:27:41 -0700334 h->resv_huge_pages--;
Mel Gormana1e78772008-07-23 21:27:23 -0700335 }
336}
337
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700338/* Reset counters to 0 and clear all HPAGE_RESV_* flags */
Mel Gormana1e78772008-07-23 21:27:23 -0700339void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
340{
341 VM_BUG_ON(!is_vm_hugetlb_page(vma));
342 if (!(vma->vm_flags & VM_SHARED))
343 vma->vm_private_data = (void *)0;
344}
345
346/* Returns true if the VMA has associated reserve pages */
Mel Gorman7f09ca52008-07-23 21:27:58 -0700347static int vma_has_reserves(struct vm_area_struct *vma)
Mel Gormana1e78772008-07-23 21:27:23 -0700348{
349 if (vma->vm_flags & VM_SHARED)
Mel Gorman7f09ca52008-07-23 21:27:58 -0700350 return 1;
351 if (is_vma_resv_set(vma, HPAGE_RESV_OWNER))
352 return 1;
353 return 0;
Mel Gormana1e78772008-07-23 21:27:23 -0700354}
355
Andi Kleena5516432008-07-23 21:27:41 -0700356static void clear_huge_page(struct page *page,
357 unsigned long addr, unsigned long sz)
David Gibson79ac6ba2006-03-22 00:08:51 -0800358{
359 int i;
360
361 might_sleep();
Andi Kleena5516432008-07-23 21:27:41 -0700362 for (i = 0; i < sz/PAGE_SIZE; i++) {
David Gibson79ac6ba2006-03-22 00:08:51 -0800363 cond_resched();
Ralf Baechle281e0e32007-10-01 01:20:10 -0700364 clear_user_highpage(page + i, addr + i * PAGE_SIZE);
David Gibson79ac6ba2006-03-22 00:08:51 -0800365 }
366}
367
368static void copy_huge_page(struct page *dst, struct page *src,
Atsushi Nemoto9de455b2006-12-12 17:14:55 +0000369 unsigned long addr, struct vm_area_struct *vma)
David Gibson79ac6ba2006-03-22 00:08:51 -0800370{
371 int i;
Andi Kleena5516432008-07-23 21:27:41 -0700372 struct hstate *h = hstate_vma(vma);
David Gibson79ac6ba2006-03-22 00:08:51 -0800373
374 might_sleep();
Andi Kleena5516432008-07-23 21:27:41 -0700375 for (i = 0; i < pages_per_huge_page(h); i++) {
David Gibson79ac6ba2006-03-22 00:08:51 -0800376 cond_resched();
Atsushi Nemoto9de455b2006-12-12 17:14:55 +0000377 copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma);
David Gibson79ac6ba2006-03-22 00:08:51 -0800378 }
379}
380
Andi Kleena5516432008-07-23 21:27:41 -0700381static void enqueue_huge_page(struct hstate *h, struct page *page)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382{
383 int nid = page_to_nid(page);
Andi Kleena5516432008-07-23 21:27:41 -0700384 list_add(&page->lru, &h->hugepage_freelists[nid]);
385 h->free_huge_pages++;
386 h->free_huge_pages_node[nid]++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387}
388
Andi Kleena5516432008-07-23 21:27:41 -0700389static struct page *dequeue_huge_page(struct hstate *h)
Nishanth Aravamudan348e1e02008-03-04 14:29:42 -0800390{
391 int nid;
392 struct page *page = NULL;
393
394 for (nid = 0; nid < MAX_NUMNODES; ++nid) {
Andi Kleena5516432008-07-23 21:27:41 -0700395 if (!list_empty(&h->hugepage_freelists[nid])) {
396 page = list_entry(h->hugepage_freelists[nid].next,
Nishanth Aravamudan348e1e02008-03-04 14:29:42 -0800397 struct page, lru);
398 list_del(&page->lru);
Andi Kleena5516432008-07-23 21:27:41 -0700399 h->free_huge_pages--;
400 h->free_huge_pages_node[nid]--;
Nishanth Aravamudan348e1e02008-03-04 14:29:42 -0800401 break;
402 }
403 }
404 return page;
405}
406
Andi Kleena5516432008-07-23 21:27:41 -0700407static struct page *dequeue_huge_page_vma(struct hstate *h,
408 struct vm_area_struct *vma,
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700409 unsigned long address, int avoid_reserve)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410{
Nishanth Aravamudan31a5c6e2007-07-15 23:38:02 -0700411 int nid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 struct page *page = NULL;
Lee Schermerhorn480eccf2007-09-18 22:46:47 -0700413 struct mempolicy *mpol;
Mel Gorman19770b32008-04-28 02:12:18 -0700414 nodemask_t *nodemask;
Mel Gorman396faf02007-07-17 04:03:13 -0700415 struct zonelist *zonelist = huge_zonelist(vma, address,
Mel Gorman19770b32008-04-28 02:12:18 -0700416 htlb_alloc_mask, &mpol, &nodemask);
Mel Gormandd1a2392008-04-28 02:12:17 -0700417 struct zone *zone;
418 struct zoneref *z;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419
Mel Gormana1e78772008-07-23 21:27:23 -0700420 /*
421 * A child process with MAP_PRIVATE mappings created by their parent
422 * have no page reserves. This check ensures that reservations are
423 * not "stolen". The child may still get SIGKILLed
424 */
Mel Gorman7f09ca52008-07-23 21:27:58 -0700425 if (!vma_has_reserves(vma) &&
Andi Kleena5516432008-07-23 21:27:41 -0700426 h->free_huge_pages - h->resv_huge_pages == 0)
Mel Gormana1e78772008-07-23 21:27:23 -0700427 return NULL;
428
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700429 /* If reserves cannot be used, ensure enough pages are in the pool */
Andi Kleena5516432008-07-23 21:27:41 -0700430 if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0)
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700431 return NULL;
432
Mel Gorman19770b32008-04-28 02:12:18 -0700433 for_each_zone_zonelist_nodemask(zone, z, zonelist,
434 MAX_NR_ZONES - 1, nodemask) {
Mel Gorman54a6eb52008-04-28 02:12:16 -0700435 nid = zone_to_nid(zone);
436 if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) &&
Andi Kleena5516432008-07-23 21:27:41 -0700437 !list_empty(&h->hugepage_freelists[nid])) {
438 page = list_entry(h->hugepage_freelists[nid].next,
Andrew Morton3abf7af2007-07-19 01:49:08 -0700439 struct page, lru);
440 list_del(&page->lru);
Andi Kleena5516432008-07-23 21:27:41 -0700441 h->free_huge_pages--;
442 h->free_huge_pages_node[nid]--;
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700443
444 if (!avoid_reserve)
Andi Kleena5516432008-07-23 21:27:41 -0700445 decrement_hugepage_resv_vma(h, vma);
Mel Gormana1e78772008-07-23 21:27:23 -0700446
Ken Chen5ab3ee72007-07-23 18:44:00 -0700447 break;
Andrew Morton3abf7af2007-07-19 01:49:08 -0700448 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 }
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700450 mpol_cond_put(mpol);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451 return page;
452}
453
Andi Kleena5516432008-07-23 21:27:41 -0700454static void update_and_free_page(struct hstate *h, struct page *page)
Adam Litke6af2acb2007-10-16 01:26:16 -0700455{
456 int i;
Andi Kleena5516432008-07-23 21:27:41 -0700457
458 h->nr_huge_pages--;
459 h->nr_huge_pages_node[page_to_nid(page)]--;
460 for (i = 0; i < pages_per_huge_page(h); i++) {
Adam Litke6af2acb2007-10-16 01:26:16 -0700461 page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced |
462 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved |
463 1 << PG_private | 1<< PG_writeback);
464 }
465 set_compound_page_dtor(page, NULL);
466 set_page_refcounted(page);
Gerald Schaefer7f2e9522008-04-28 02:13:29 -0700467 arch_release_hugepage(page);
Andi Kleena5516432008-07-23 21:27:41 -0700468 __free_pages(page, huge_page_order(h));
Adam Litke6af2acb2007-10-16 01:26:16 -0700469}
470
Andi Kleene5ff2152008-07-23 21:27:42 -0700471struct hstate *size_to_hstate(unsigned long size)
472{
473 struct hstate *h;
474
475 for_each_hstate(h) {
476 if (huge_page_size(h) == size)
477 return h;
478 }
479 return NULL;
480}
481
David Gibson27a85ef2006-03-22 00:08:56 -0800482static void free_huge_page(struct page *page)
483{
Andi Kleena5516432008-07-23 21:27:41 -0700484 /*
485 * Can't pass hstate in here because it is called from the
486 * compound page destructor.
487 */
Andi Kleene5ff2152008-07-23 21:27:42 -0700488 struct hstate *h = page_hstate(page);
Adam Litke7893d1d2007-10-16 01:26:18 -0700489 int nid = page_to_nid(page);
Adam Litkec79fb752007-11-14 16:59:38 -0800490 struct address_space *mapping;
David Gibson27a85ef2006-03-22 00:08:56 -0800491
Adam Litkec79fb752007-11-14 16:59:38 -0800492 mapping = (struct address_space *) page_private(page);
Andy Whitcrofte5df70a2008-02-23 15:23:32 -0800493 set_page_private(page, 0);
Adam Litke7893d1d2007-10-16 01:26:18 -0700494 BUG_ON(page_count(page));
David Gibson27a85ef2006-03-22 00:08:56 -0800495 INIT_LIST_HEAD(&page->lru);
496
497 spin_lock(&hugetlb_lock);
Andi Kleenaa888a72008-07-23 21:27:47 -0700498 if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) {
Andi Kleena5516432008-07-23 21:27:41 -0700499 update_and_free_page(h, page);
500 h->surplus_huge_pages--;
501 h->surplus_huge_pages_node[nid]--;
Adam Litke7893d1d2007-10-16 01:26:18 -0700502 } else {
Andi Kleena5516432008-07-23 21:27:41 -0700503 enqueue_huge_page(h, page);
Adam Litke7893d1d2007-10-16 01:26:18 -0700504 }
David Gibson27a85ef2006-03-22 00:08:56 -0800505 spin_unlock(&hugetlb_lock);
Adam Litkec79fb752007-11-14 16:59:38 -0800506 if (mapping)
Adam Litke9a119c02007-11-14 16:59:41 -0800507 hugetlb_put_quota(mapping, 1);
David Gibson27a85ef2006-03-22 00:08:56 -0800508}
509
Adam Litke7893d1d2007-10-16 01:26:18 -0700510/*
511 * Increment or decrement surplus_huge_pages. Keep node-specific counters
512 * balanced by operating on them in a round-robin fashion.
513 * Returns 1 if an adjustment was made.
514 */
Andi Kleena5516432008-07-23 21:27:41 -0700515static int adjust_pool_surplus(struct hstate *h, int delta)
Adam Litke7893d1d2007-10-16 01:26:18 -0700516{
517 static int prev_nid;
518 int nid = prev_nid;
519 int ret = 0;
520
521 VM_BUG_ON(delta != -1 && delta != 1);
522 do {
523 nid = next_node(nid, node_online_map);
524 if (nid == MAX_NUMNODES)
525 nid = first_node(node_online_map);
526
527 /* To shrink on this node, there must be a surplus page */
Andi Kleena5516432008-07-23 21:27:41 -0700528 if (delta < 0 && !h->surplus_huge_pages_node[nid])
Adam Litke7893d1d2007-10-16 01:26:18 -0700529 continue;
530 /* Surplus cannot exceed the total number of pages */
Andi Kleena5516432008-07-23 21:27:41 -0700531 if (delta > 0 && h->surplus_huge_pages_node[nid] >=
532 h->nr_huge_pages_node[nid])
Adam Litke7893d1d2007-10-16 01:26:18 -0700533 continue;
534
Andi Kleena5516432008-07-23 21:27:41 -0700535 h->surplus_huge_pages += delta;
536 h->surplus_huge_pages_node[nid] += delta;
Adam Litke7893d1d2007-10-16 01:26:18 -0700537 ret = 1;
538 break;
539 } while (nid != prev_nid);
540
541 prev_nid = nid;
542 return ret;
543}
544
Andi Kleena5516432008-07-23 21:27:41 -0700545static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
Andi Kleenb7ba30c2008-07-23 21:27:40 -0700546{
547 set_compound_page_dtor(page, free_huge_page);
548 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -0700549 h->nr_huge_pages++;
550 h->nr_huge_pages_node[nid]++;
Andi Kleenb7ba30c2008-07-23 21:27:40 -0700551 spin_unlock(&hugetlb_lock);
552 put_page(page); /* free it into the hugepage allocator */
553}
554
Andi Kleena5516432008-07-23 21:27:41 -0700555static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 struct page *page;
Joe Jinf96efd52007-07-15 23:38:12 -0700558
Andi Kleenaa888a72008-07-23 21:27:47 -0700559 if (h->order >= MAX_ORDER)
560 return NULL;
561
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700562 page = alloc_pages_node(nid,
Nishanth Aravamudan551883a2008-04-29 00:58:26 -0700563 htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
564 __GFP_REPEAT|__GFP_NOWARN,
Andi Kleena5516432008-07-23 21:27:41 -0700565 huge_page_order(h));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 if (page) {
Gerald Schaefer7f2e9522008-04-28 02:13:29 -0700567 if (arch_prepare_hugepage(page)) {
Gerald Schaefercaff3a22008-08-12 15:08:38 -0700568 __free_pages(page, huge_page_order(h));
Harvey Harrison7b8ee842008-04-28 14:13:19 -0700569 return NULL;
Gerald Schaefer7f2e9522008-04-28 02:13:29 -0700570 }
Andi Kleena5516432008-07-23 21:27:41 -0700571 prep_new_huge_page(h, page, nid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 }
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700573
574 return page;
575}
576
Andi Kleen5ced66c2008-07-23 21:27:45 -0700577/*
578 * Use a helper variable to find the next node and then
579 * copy it back to hugetlb_next_nid afterwards:
580 * otherwise there's a window in which a racer might
581 * pass invalid nid MAX_NUMNODES to alloc_pages_node.
582 * But we don't need to use a spin_lock here: it really
583 * doesn't matter if occasionally a racer chooses the
584 * same nid as we do. Move nid forward in the mask even
585 * if we just successfully allocated a hugepage so that
586 * the next caller gets hugepages on the next node.
587 */
588static int hstate_next_node(struct hstate *h)
589{
590 int next_nid;
591 next_nid = next_node(h->hugetlb_next_nid, node_online_map);
592 if (next_nid == MAX_NUMNODES)
593 next_nid = first_node(node_online_map);
594 h->hugetlb_next_nid = next_nid;
595 return next_nid;
596}
597
Andi Kleena5516432008-07-23 21:27:41 -0700598static int alloc_fresh_huge_page(struct hstate *h)
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700599{
600 struct page *page;
601 int start_nid;
602 int next_nid;
603 int ret = 0;
604
Andi Kleena5516432008-07-23 21:27:41 -0700605 start_nid = h->hugetlb_next_nid;
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700606
607 do {
Andi Kleena5516432008-07-23 21:27:41 -0700608 page = alloc_fresh_huge_page_node(h, h->hugetlb_next_nid);
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700609 if (page)
610 ret = 1;
Andi Kleen5ced66c2008-07-23 21:27:45 -0700611 next_nid = hstate_next_node(h);
Andi Kleena5516432008-07-23 21:27:41 -0700612 } while (!page && h->hugetlb_next_nid != start_nid);
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700613
Adam Litke3b116302008-04-28 02:13:06 -0700614 if (ret)
615 count_vm_event(HTLB_BUDDY_PGALLOC);
616 else
617 count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
618
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700619 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620}
621
Andi Kleena5516432008-07-23 21:27:41 -0700622static struct page *alloc_buddy_huge_page(struct hstate *h,
623 struct vm_area_struct *vma, unsigned long address)
Adam Litke7893d1d2007-10-16 01:26:18 -0700624{
625 struct page *page;
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800626 unsigned int nid;
Adam Litke7893d1d2007-10-16 01:26:18 -0700627
Andi Kleenaa888a72008-07-23 21:27:47 -0700628 if (h->order >= MAX_ORDER)
629 return NULL;
630
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800631 /*
632 * Assume we will successfully allocate the surplus page to
633 * prevent racing processes from causing the surplus to exceed
634 * overcommit
635 *
636 * This however introduces a different race, where a process B
637 * tries to grow the static hugepage pool while alloc_pages() is
638 * called by process A. B will only examine the per-node
639 * counters in determining if surplus huge pages can be
640 * converted to normal huge pages in adjust_pool_surplus(). A
641 * won't be able to increment the per-node counter, until the
642 * lock is dropped by B, but B doesn't drop hugetlb_lock until
643 * no more huge pages can be converted from surplus to normal
644 * state (and doesn't try to convert again). Thus, we have a
645 * case where a surplus huge page exists, the pool is grown, and
646 * the surplus huge page still exists after, even though it
647 * should just have been converted to a normal huge page. This
648 * does not leak memory, though, as the hugepage will be freed
649 * once it is out of use. It also does not allow the counters to
650 * go out of whack in adjust_pool_surplus() as we don't modify
651 * the node values until we've gotten the hugepage and only the
652 * per-node value is checked there.
653 */
654 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -0700655 if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) {
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800656 spin_unlock(&hugetlb_lock);
657 return NULL;
658 } else {
Andi Kleena5516432008-07-23 21:27:41 -0700659 h->nr_huge_pages++;
660 h->surplus_huge_pages++;
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800661 }
662 spin_unlock(&hugetlb_lock);
663
Nishanth Aravamudan551883a2008-04-29 00:58:26 -0700664 page = alloc_pages(htlb_alloc_mask|__GFP_COMP|
665 __GFP_REPEAT|__GFP_NOWARN,
Andi Kleena5516432008-07-23 21:27:41 -0700666 huge_page_order(h));
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800667
Gerald Schaefercaff3a22008-08-12 15:08:38 -0700668 if (page && arch_prepare_hugepage(page)) {
669 __free_pages(page, huge_page_order(h));
670 return NULL;
671 }
672
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800673 spin_lock(&hugetlb_lock);
Adam Litke7893d1d2007-10-16 01:26:18 -0700674 if (page) {
Adam Litke2668db92008-03-10 11:43:50 -0700675 /*
676 * This page is now managed by the hugetlb allocator and has
677 * no users -- drop the buddy allocator's reference.
678 */
679 put_page_testzero(page);
680 VM_BUG_ON(page_count(page));
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800681 nid = page_to_nid(page);
Adam Litke7893d1d2007-10-16 01:26:18 -0700682 set_compound_page_dtor(page, free_huge_page);
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800683 /*
684 * We incremented the global counters already
685 */
Andi Kleena5516432008-07-23 21:27:41 -0700686 h->nr_huge_pages_node[nid]++;
687 h->surplus_huge_pages_node[nid]++;
Adam Litke3b116302008-04-28 02:13:06 -0700688 __count_vm_event(HTLB_BUDDY_PGALLOC);
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800689 } else {
Andi Kleena5516432008-07-23 21:27:41 -0700690 h->nr_huge_pages--;
691 h->surplus_huge_pages--;
Adam Litke3b116302008-04-28 02:13:06 -0700692 __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
Adam Litke7893d1d2007-10-16 01:26:18 -0700693 }
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800694 spin_unlock(&hugetlb_lock);
Adam Litke7893d1d2007-10-16 01:26:18 -0700695
696 return page;
697}
698
Adam Litkee4e574b2007-10-16 01:26:19 -0700699/*
700 * Increase the hugetlb pool such that it can accomodate a reservation
701 * of size 'delta'.
702 */
Andi Kleena5516432008-07-23 21:27:41 -0700703static int gather_surplus_pages(struct hstate *h, int delta)
Adam Litkee4e574b2007-10-16 01:26:19 -0700704{
705 struct list_head surplus_list;
706 struct page *page, *tmp;
707 int ret, i;
708 int needed, allocated;
709
Andi Kleena5516432008-07-23 21:27:41 -0700710 needed = (h->resv_huge_pages + delta) - h->free_huge_pages;
Adam Litkeac09b3a2008-03-04 14:29:38 -0800711 if (needed <= 0) {
Andi Kleena5516432008-07-23 21:27:41 -0700712 h->resv_huge_pages += delta;
Adam Litkee4e574b2007-10-16 01:26:19 -0700713 return 0;
Adam Litkeac09b3a2008-03-04 14:29:38 -0800714 }
Adam Litkee4e574b2007-10-16 01:26:19 -0700715
716 allocated = 0;
717 INIT_LIST_HEAD(&surplus_list);
718
719 ret = -ENOMEM;
720retry:
721 spin_unlock(&hugetlb_lock);
722 for (i = 0; i < needed; i++) {
Andi Kleena5516432008-07-23 21:27:41 -0700723 page = alloc_buddy_huge_page(h, NULL, 0);
Adam Litkee4e574b2007-10-16 01:26:19 -0700724 if (!page) {
725 /*
726 * We were not able to allocate enough pages to
727 * satisfy the entire reservation so we free what
728 * we've allocated so far.
729 */
730 spin_lock(&hugetlb_lock);
731 needed = 0;
732 goto free;
733 }
734
735 list_add(&page->lru, &surplus_list);
736 }
737 allocated += needed;
738
739 /*
740 * After retaking hugetlb_lock, we need to recalculate 'needed'
741 * because either resv_huge_pages or free_huge_pages may have changed.
742 */
743 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -0700744 needed = (h->resv_huge_pages + delta) -
745 (h->free_huge_pages + allocated);
Adam Litkee4e574b2007-10-16 01:26:19 -0700746 if (needed > 0)
747 goto retry;
748
749 /*
750 * The surplus_list now contains _at_least_ the number of extra pages
751 * needed to accomodate the reservation. Add the appropriate number
752 * of pages to the hugetlb pool and free the extras back to the buddy
Adam Litkeac09b3a2008-03-04 14:29:38 -0800753 * allocator. Commit the entire reservation here to prevent another
754 * process from stealing the pages as they are added to the pool but
755 * before they are reserved.
Adam Litkee4e574b2007-10-16 01:26:19 -0700756 */
757 needed += allocated;
Andi Kleena5516432008-07-23 21:27:41 -0700758 h->resv_huge_pages += delta;
Adam Litkee4e574b2007-10-16 01:26:19 -0700759 ret = 0;
760free:
Adam Litke19fc3f02008-04-28 02:12:20 -0700761 /* Free the needed pages to the hugetlb pool */
Adam Litkee4e574b2007-10-16 01:26:19 -0700762 list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
Adam Litke19fc3f02008-04-28 02:12:20 -0700763 if ((--needed) < 0)
764 break;
Adam Litkee4e574b2007-10-16 01:26:19 -0700765 list_del(&page->lru);
Andi Kleena5516432008-07-23 21:27:41 -0700766 enqueue_huge_page(h, page);
Adam Litke19fc3f02008-04-28 02:12:20 -0700767 }
768
769 /* Free unnecessary surplus pages to the buddy allocator */
770 if (!list_empty(&surplus_list)) {
771 spin_unlock(&hugetlb_lock);
772 list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
773 list_del(&page->lru);
Adam Litkeaf767cb2007-10-16 01:26:25 -0700774 /*
Adam Litke2668db92008-03-10 11:43:50 -0700775 * The page has a reference count of zero already, so
776 * call free_huge_page directly instead of using
777 * put_page. This must be done with hugetlb_lock
Adam Litkeaf767cb2007-10-16 01:26:25 -0700778 * unlocked which is safe because free_huge_page takes
779 * hugetlb_lock before deciding how to free the page.
780 */
Adam Litke2668db92008-03-10 11:43:50 -0700781 free_huge_page(page);
Adam Litkeaf767cb2007-10-16 01:26:25 -0700782 }
Adam Litke19fc3f02008-04-28 02:12:20 -0700783 spin_lock(&hugetlb_lock);
Adam Litkee4e574b2007-10-16 01:26:19 -0700784 }
785
786 return ret;
787}
788
789/*
790 * When releasing a hugetlb pool reservation, any surplus pages that were
791 * allocated to satisfy the reservation must be explicitly freed if they were
792 * never used.
793 */
Andi Kleena5516432008-07-23 21:27:41 -0700794static void return_unused_surplus_pages(struct hstate *h,
795 unsigned long unused_resv_pages)
Adam Litkee4e574b2007-10-16 01:26:19 -0700796{
797 static int nid = -1;
798 struct page *page;
799 unsigned long nr_pages;
800
Nishanth Aravamudan11320d12008-03-26 14:40:20 -0700801 /*
802 * We want to release as many surplus pages as possible, spread
803 * evenly across all nodes. Iterate across all nodes until we
804 * can no longer free unreserved surplus pages. This occurs when
805 * the nodes with surplus pages have no free pages.
806 */
807 unsigned long remaining_iterations = num_online_nodes();
808
Adam Litkeac09b3a2008-03-04 14:29:38 -0800809 /* Uncommit the reservation */
Andi Kleena5516432008-07-23 21:27:41 -0700810 h->resv_huge_pages -= unused_resv_pages;
Adam Litkeac09b3a2008-03-04 14:29:38 -0800811
Andi Kleenaa888a72008-07-23 21:27:47 -0700812 /* Cannot return gigantic pages currently */
813 if (h->order >= MAX_ORDER)
814 return;
815
Andi Kleena5516432008-07-23 21:27:41 -0700816 nr_pages = min(unused_resv_pages, h->surplus_huge_pages);
Adam Litkee4e574b2007-10-16 01:26:19 -0700817
Nishanth Aravamudan11320d12008-03-26 14:40:20 -0700818 while (remaining_iterations-- && nr_pages) {
Adam Litkee4e574b2007-10-16 01:26:19 -0700819 nid = next_node(nid, node_online_map);
820 if (nid == MAX_NUMNODES)
821 nid = first_node(node_online_map);
822
Andi Kleena5516432008-07-23 21:27:41 -0700823 if (!h->surplus_huge_pages_node[nid])
Adam Litkee4e574b2007-10-16 01:26:19 -0700824 continue;
825
Andi Kleena5516432008-07-23 21:27:41 -0700826 if (!list_empty(&h->hugepage_freelists[nid])) {
827 page = list_entry(h->hugepage_freelists[nid].next,
Adam Litkee4e574b2007-10-16 01:26:19 -0700828 struct page, lru);
829 list_del(&page->lru);
Andi Kleena5516432008-07-23 21:27:41 -0700830 update_and_free_page(h, page);
831 h->free_huge_pages--;
832 h->free_huge_pages_node[nid]--;
833 h->surplus_huge_pages--;
834 h->surplus_huge_pages_node[nid]--;
Adam Litkee4e574b2007-10-16 01:26:19 -0700835 nr_pages--;
Nishanth Aravamudan11320d12008-03-26 14:40:20 -0700836 remaining_iterations = num_online_nodes();
Adam Litkee4e574b2007-10-16 01:26:19 -0700837 }
838 }
839}
840
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700841/*
842 * Determine if the huge page at addr within the vma has an associated
843 * reservation. Where it does not we will need to logically increase
844 * reservation and actually increase quota before an allocation can occur.
845 * Where any new reservation would be required the reservation change is
846 * prepared, but not committed. Once the page has been quota'd allocated
847 * an instantiated the change should be committed via vma_commit_reservation.
848 * No action is required on failure.
849 */
Andi Kleena5516432008-07-23 21:27:41 -0700850static int vma_needs_reservation(struct hstate *h,
851 struct vm_area_struct *vma, unsigned long addr)
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700852{
853 struct address_space *mapping = vma->vm_file->f_mapping;
854 struct inode *inode = mapping->host;
855
856 if (vma->vm_flags & VM_SHARED) {
Andi Kleena5516432008-07-23 21:27:41 -0700857 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700858 return region_chg(&inode->i_mapping->private_list,
859 idx, idx + 1);
860
Andy Whitcroft84afd992008-07-23 21:27:32 -0700861 } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
862 return 1;
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700863
Andy Whitcroft84afd992008-07-23 21:27:32 -0700864 } else {
865 int err;
Andi Kleena5516432008-07-23 21:27:41 -0700866 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
Andy Whitcroft84afd992008-07-23 21:27:32 -0700867 struct resv_map *reservations = vma_resv_map(vma);
868
869 err = region_chg(&reservations->regions, idx, idx + 1);
870 if (err < 0)
871 return err;
872 return 0;
873 }
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700874}
Andi Kleena5516432008-07-23 21:27:41 -0700875static void vma_commit_reservation(struct hstate *h,
876 struct vm_area_struct *vma, unsigned long addr)
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700877{
878 struct address_space *mapping = vma->vm_file->f_mapping;
879 struct inode *inode = mapping->host;
880
881 if (vma->vm_flags & VM_SHARED) {
Andi Kleena5516432008-07-23 21:27:41 -0700882 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700883 region_add(&inode->i_mapping->private_list, idx, idx + 1);
Andy Whitcroft84afd992008-07-23 21:27:32 -0700884
885 } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
Andi Kleena5516432008-07-23 21:27:41 -0700886 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
Andy Whitcroft84afd992008-07-23 21:27:32 -0700887 struct resv_map *reservations = vma_resv_map(vma);
888
889 /* Mark this page used in the map. */
890 region_add(&reservations->regions, idx, idx + 1);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700891 }
892}
893
David Gibson27a85ef2006-03-22 00:08:56 -0800894static struct page *alloc_huge_page(struct vm_area_struct *vma,
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700895 unsigned long addr, int avoid_reserve)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896{
Andi Kleena5516432008-07-23 21:27:41 -0700897 struct hstate *h = hstate_vma(vma);
Adam Litke348ea202007-11-14 16:59:37 -0800898 struct page *page;
Adam Litke2fc39ce2007-11-14 16:59:39 -0800899 struct address_space *mapping = vma->vm_file->f_mapping;
Mel Gormana1e78772008-07-23 21:27:23 -0700900 struct inode *inode = mapping->host;
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700901 unsigned int chg;
Adam Litke2fc39ce2007-11-14 16:59:39 -0800902
Mel Gormana1e78772008-07-23 21:27:23 -0700903 /*
904 * Processes that did not create the mapping will have no reserves and
905 * will not have accounted against quota. Check that the quota can be
906 * made before satisfying the allocation
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700907 * MAP_NORESERVE mappings may also need pages and quota allocated
908 * if no reserve mapping overlaps.
Mel Gormana1e78772008-07-23 21:27:23 -0700909 */
Andi Kleena5516432008-07-23 21:27:41 -0700910 chg = vma_needs_reservation(h, vma, addr);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700911 if (chg < 0)
912 return ERR_PTR(chg);
913 if (chg)
Mel Gormana1e78772008-07-23 21:27:23 -0700914 if (hugetlb_get_quota(inode->i_mapping, chg))
915 return ERR_PTR(-ENOSPC);
Mel Gormana1e78772008-07-23 21:27:23 -0700916
917 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -0700918 page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve);
Mel Gormana1e78772008-07-23 21:27:23 -0700919 spin_unlock(&hugetlb_lock);
920
921 if (!page) {
Andi Kleena5516432008-07-23 21:27:41 -0700922 page = alloc_buddy_huge_page(h, vma, addr);
Mel Gormana1e78772008-07-23 21:27:23 -0700923 if (!page) {
924 hugetlb_put_quota(inode->i_mapping, chg);
925 return ERR_PTR(-VM_FAULT_OOM);
926 }
927 }
928
929 set_page_refcounted(page);
930 set_page_private(page, (unsigned long) mapping);
931
Andi Kleena5516432008-07-23 21:27:41 -0700932 vma_commit_reservation(h, vma, addr);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700933
Adam Litke90d8b7e2007-11-14 16:59:42 -0800934 return page;
David Gibsonb45b5bd2006-03-22 00:08:55 -0800935}
936
Jon Tollefson53ba51d2008-07-23 21:27:52 -0700937__attribute__((weak)) int alloc_bootmem_huge_page(struct hstate *h)
Andi Kleenaa888a72008-07-23 21:27:47 -0700938{
939 struct huge_bootmem_page *m;
940 int nr_nodes = nodes_weight(node_online_map);
941
942 while (nr_nodes) {
943 void *addr;
944
945 addr = __alloc_bootmem_node_nopanic(
946 NODE_DATA(h->hugetlb_next_nid),
947 huge_page_size(h), huge_page_size(h), 0);
948
949 if (addr) {
950 /*
951 * Use the beginning of the huge page to store the
952 * huge_bootmem_page struct (until gather_bootmem
953 * puts them into the mem_map).
954 */
955 m = addr;
956 if (m)
957 goto found;
958 }
959 hstate_next_node(h);
960 nr_nodes--;
961 }
962 return 0;
963
964found:
965 BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1));
966 /* Put them into a private list first because mem_map is not up yet */
967 list_add(&m->list, &huge_boot_pages);
968 m->hstate = h;
969 return 1;
970}
971
972/* Put bootmem huge pages into the standard lists after mem_map is up */
973static void __init gather_bootmem_prealloc(void)
974{
975 struct huge_bootmem_page *m;
976
977 list_for_each_entry(m, &huge_boot_pages, list) {
978 struct page *page = virt_to_page(m);
979 struct hstate *h = m->hstate;
980 __ClearPageReserved(page);
981 WARN_ON(page_count(page) != 1);
982 prep_compound_page(page, h->order);
983 prep_new_huge_page(h, page, page_to_nid(page));
984 }
985}
986
Andi Kleen8faa8b02008-07-23 21:27:48 -0700987static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988{
989 unsigned long i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990
Andi Kleene5ff2152008-07-23 21:27:42 -0700991 for (i = 0; i < h->max_huge_pages; ++i) {
Andi Kleenaa888a72008-07-23 21:27:47 -0700992 if (h->order >= MAX_ORDER) {
993 if (!alloc_bootmem_huge_page(h))
994 break;
995 } else if (!alloc_fresh_huge_page(h))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997 }
Andi Kleen8faa8b02008-07-23 21:27:48 -0700998 h->max_huge_pages = i;
Andi Kleene5ff2152008-07-23 21:27:42 -0700999}
1000
1001static void __init hugetlb_init_hstates(void)
1002{
1003 struct hstate *h;
1004
1005 for_each_hstate(h) {
Andi Kleen8faa8b02008-07-23 21:27:48 -07001006 /* oversize hugepages were init'ed in early boot */
1007 if (h->order < MAX_ORDER)
1008 hugetlb_hstate_alloc_pages(h);
Andi Kleene5ff2152008-07-23 21:27:42 -07001009 }
1010}
1011
Andi Kleen4abd32d2008-07-23 21:27:49 -07001012static char * __init memfmt(char *buf, unsigned long n)
1013{
1014 if (n >= (1UL << 30))
1015 sprintf(buf, "%lu GB", n >> 30);
1016 else if (n >= (1UL << 20))
1017 sprintf(buf, "%lu MB", n >> 20);
1018 else
1019 sprintf(buf, "%lu KB", n >> 10);
1020 return buf;
1021}
1022
Andi Kleene5ff2152008-07-23 21:27:42 -07001023static void __init report_hugepages(void)
1024{
1025 struct hstate *h;
1026
1027 for_each_hstate(h) {
Andi Kleen4abd32d2008-07-23 21:27:49 -07001028 char buf[32];
1029 printk(KERN_INFO "HugeTLB registered %s page size, "
1030 "pre-allocated %ld pages\n",
1031 memfmt(buf, huge_page_size(h)),
1032 h->free_huge_pages);
Andi Kleene5ff2152008-07-23 21:27:42 -07001033 }
1034}
1035
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036#ifdef CONFIG_HIGHMEM
Andi Kleena5516432008-07-23 21:27:41 -07001037static void try_to_free_low(struct hstate *h, unsigned long count)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038{
Christoph Lameter4415cc82006-09-25 23:31:55 -07001039 int i;
1040
Andi Kleenaa888a72008-07-23 21:27:47 -07001041 if (h->order >= MAX_ORDER)
1042 return;
1043
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044 for (i = 0; i < MAX_NUMNODES; ++i) {
1045 struct page *page, *next;
Andi Kleena5516432008-07-23 21:27:41 -07001046 struct list_head *freel = &h->hugepage_freelists[i];
1047 list_for_each_entry_safe(page, next, freel, lru) {
1048 if (count >= h->nr_huge_pages)
Adam Litke6b0c8802007-10-16 01:26:23 -07001049 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050 if (PageHighMem(page))
1051 continue;
1052 list_del(&page->lru);
Andi Kleene5ff2152008-07-23 21:27:42 -07001053 update_and_free_page(h, page);
Andi Kleena5516432008-07-23 21:27:41 -07001054 h->free_huge_pages--;
1055 h->free_huge_pages_node[page_to_nid(page)]--;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001056 }
1057 }
1058}
1059#else
Andi Kleena5516432008-07-23 21:27:41 -07001060static inline void try_to_free_low(struct hstate *h, unsigned long count)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001061{
1062}
1063#endif
1064
Andi Kleena5516432008-07-23 21:27:41 -07001065#define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)
Andi Kleene5ff2152008-07-23 21:27:42 -07001066static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067{
Adam Litke7893d1d2007-10-16 01:26:18 -07001068 unsigned long min_count, ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001069
Andi Kleenaa888a72008-07-23 21:27:47 -07001070 if (h->order >= MAX_ORDER)
1071 return h->max_huge_pages;
1072
Adam Litke7893d1d2007-10-16 01:26:18 -07001073 /*
1074 * Increase the pool size
1075 * First take pages out of surplus state. Then make up the
1076 * remaining difference by allocating fresh huge pages.
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -08001077 *
1078 * We might race with alloc_buddy_huge_page() here and be unable
1079 * to convert a surplus huge page to a normal huge page. That is
1080 * not critical, though, it just means the overall size of the
1081 * pool might be one hugepage larger than it needs to be, but
1082 * within all the constraints specified by the sysctls.
Adam Litke7893d1d2007-10-16 01:26:18 -07001083 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001084 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -07001085 while (h->surplus_huge_pages && count > persistent_huge_pages(h)) {
1086 if (!adjust_pool_surplus(h, -1))
Adam Litke7893d1d2007-10-16 01:26:18 -07001087 break;
1088 }
1089
Andi Kleena5516432008-07-23 21:27:41 -07001090 while (count > persistent_huge_pages(h)) {
Adam Litke7893d1d2007-10-16 01:26:18 -07001091 /*
1092 * If this allocation races such that we no longer need the
1093 * page, free_huge_page will handle it by freeing the page
1094 * and reducing the surplus.
1095 */
1096 spin_unlock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -07001097 ret = alloc_fresh_huge_page(h);
Adam Litke7893d1d2007-10-16 01:26:18 -07001098 spin_lock(&hugetlb_lock);
1099 if (!ret)
1100 goto out;
1101
1102 }
Adam Litke7893d1d2007-10-16 01:26:18 -07001103
1104 /*
1105 * Decrease the pool size
1106 * First return free pages to the buddy allocator (being careful
1107 * to keep enough around to satisfy reservations). Then place
1108 * pages into surplus state as needed so the pool will shrink
1109 * to the desired size as pages become free.
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -08001110 *
1111 * By placing pages into the surplus state independent of the
1112 * overcommit value, we are allowing the surplus pool size to
1113 * exceed overcommit. There are few sane options here. Since
1114 * alloc_buddy_huge_page() is checking the global counter,
1115 * though, we'll note that we're not allowed to exceed surplus
1116 * and won't grow the pool anywhere else. Not until one of the
1117 * sysctls are changed, or the surplus pages go out of use.
Adam Litke7893d1d2007-10-16 01:26:18 -07001118 */
Andi Kleena5516432008-07-23 21:27:41 -07001119 min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages;
Adam Litke6b0c8802007-10-16 01:26:23 -07001120 min_count = max(count, min_count);
Andi Kleena5516432008-07-23 21:27:41 -07001121 try_to_free_low(h, min_count);
1122 while (min_count < persistent_huge_pages(h)) {
1123 struct page *page = dequeue_huge_page(h);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001124 if (!page)
1125 break;
Andi Kleena5516432008-07-23 21:27:41 -07001126 update_and_free_page(h, page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001127 }
Andi Kleena5516432008-07-23 21:27:41 -07001128 while (count < persistent_huge_pages(h)) {
1129 if (!adjust_pool_surplus(h, 1))
Adam Litke7893d1d2007-10-16 01:26:18 -07001130 break;
1131 }
1132out:
Andi Kleena5516432008-07-23 21:27:41 -07001133 ret = persistent_huge_pages(h);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 spin_unlock(&hugetlb_lock);
Adam Litke7893d1d2007-10-16 01:26:18 -07001135 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136}
1137
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001138#define HSTATE_ATTR_RO(_name) \
1139 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
1140
1141#define HSTATE_ATTR(_name) \
1142 static struct kobj_attribute _name##_attr = \
1143 __ATTR(_name, 0644, _name##_show, _name##_store)
1144
1145static struct kobject *hugepages_kobj;
1146static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];
1147
1148static struct hstate *kobj_to_hstate(struct kobject *kobj)
1149{
1150 int i;
1151 for (i = 0; i < HUGE_MAX_HSTATE; i++)
1152 if (hstate_kobjs[i] == kobj)
1153 return &hstates[i];
1154 BUG();
1155 return NULL;
1156}
1157
1158static ssize_t nr_hugepages_show(struct kobject *kobj,
1159 struct kobj_attribute *attr, char *buf)
1160{
1161 struct hstate *h = kobj_to_hstate(kobj);
1162 return sprintf(buf, "%lu\n", h->nr_huge_pages);
1163}
1164static ssize_t nr_hugepages_store(struct kobject *kobj,
1165 struct kobj_attribute *attr, const char *buf, size_t count)
1166{
1167 int err;
1168 unsigned long input;
1169 struct hstate *h = kobj_to_hstate(kobj);
1170
1171 err = strict_strtoul(buf, 10, &input);
1172 if (err)
1173 return 0;
1174
1175 h->max_huge_pages = set_max_huge_pages(h, input);
1176
1177 return count;
1178}
1179HSTATE_ATTR(nr_hugepages);
1180
1181static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj,
1182 struct kobj_attribute *attr, char *buf)
1183{
1184 struct hstate *h = kobj_to_hstate(kobj);
1185 return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages);
1186}
1187static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj,
1188 struct kobj_attribute *attr, const char *buf, size_t count)
1189{
1190 int err;
1191 unsigned long input;
1192 struct hstate *h = kobj_to_hstate(kobj);
1193
1194 err = strict_strtoul(buf, 10, &input);
1195 if (err)
1196 return 0;
1197
1198 spin_lock(&hugetlb_lock);
1199 h->nr_overcommit_huge_pages = input;
1200 spin_unlock(&hugetlb_lock);
1201
1202 return count;
1203}
1204HSTATE_ATTR(nr_overcommit_hugepages);
1205
1206static ssize_t free_hugepages_show(struct kobject *kobj,
1207 struct kobj_attribute *attr, char *buf)
1208{
1209 struct hstate *h = kobj_to_hstate(kobj);
1210 return sprintf(buf, "%lu\n", h->free_huge_pages);
1211}
1212HSTATE_ATTR_RO(free_hugepages);
1213
1214static ssize_t resv_hugepages_show(struct kobject *kobj,
1215 struct kobj_attribute *attr, char *buf)
1216{
1217 struct hstate *h = kobj_to_hstate(kobj);
1218 return sprintf(buf, "%lu\n", h->resv_huge_pages);
1219}
1220HSTATE_ATTR_RO(resv_hugepages);
1221
1222static ssize_t surplus_hugepages_show(struct kobject *kobj,
1223 struct kobj_attribute *attr, char *buf)
1224{
1225 struct hstate *h = kobj_to_hstate(kobj);
1226 return sprintf(buf, "%lu\n", h->surplus_huge_pages);
1227}
1228HSTATE_ATTR_RO(surplus_hugepages);
1229
1230static struct attribute *hstate_attrs[] = {
1231 &nr_hugepages_attr.attr,
1232 &nr_overcommit_hugepages_attr.attr,
1233 &free_hugepages_attr.attr,
1234 &resv_hugepages_attr.attr,
1235 &surplus_hugepages_attr.attr,
1236 NULL,
1237};
1238
1239static struct attribute_group hstate_attr_group = {
1240 .attrs = hstate_attrs,
1241};
1242
1243static int __init hugetlb_sysfs_add_hstate(struct hstate *h)
1244{
1245 int retval;
1246
1247 hstate_kobjs[h - hstates] = kobject_create_and_add(h->name,
1248 hugepages_kobj);
1249 if (!hstate_kobjs[h - hstates])
1250 return -ENOMEM;
1251
1252 retval = sysfs_create_group(hstate_kobjs[h - hstates],
1253 &hstate_attr_group);
1254 if (retval)
1255 kobject_put(hstate_kobjs[h - hstates]);
1256
1257 return retval;
1258}
1259
1260static void __init hugetlb_sysfs_init(void)
1261{
1262 struct hstate *h;
1263 int err;
1264
1265 hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj);
1266 if (!hugepages_kobj)
1267 return;
1268
1269 for_each_hstate(h) {
1270 err = hugetlb_sysfs_add_hstate(h);
1271 if (err)
1272 printk(KERN_ERR "Hugetlb: Unable to add hstate %s",
1273 h->name);
1274 }
1275}
1276
1277static void __exit hugetlb_exit(void)
1278{
1279 struct hstate *h;
1280
1281 for_each_hstate(h) {
1282 kobject_put(hstate_kobjs[h - hstates]);
1283 }
1284
1285 kobject_put(hugepages_kobj);
1286}
1287module_exit(hugetlb_exit);
1288
1289static int __init hugetlb_init(void)
1290{
Benjamin Herrenschmidt0ef89d22008-07-31 00:07:30 -07001291 /* Some platform decide whether they support huge pages at boot
1292 * time. On these, such as powerpc, HPAGE_SHIFT is set to 0 when
1293 * there is no such support
1294 */
1295 if (HPAGE_SHIFT == 0)
1296 return 0;
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001297
Nick Piggine11bfbf2008-07-23 21:27:52 -07001298 if (!size_to_hstate(default_hstate_size)) {
1299 default_hstate_size = HPAGE_SIZE;
1300 if (!size_to_hstate(default_hstate_size))
1301 hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001302 }
Nick Piggine11bfbf2008-07-23 21:27:52 -07001303 default_hstate_idx = size_to_hstate(default_hstate_size) - hstates;
1304 if (default_hstate_max_huge_pages)
1305 default_hstate.max_huge_pages = default_hstate_max_huge_pages;
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001306
1307 hugetlb_init_hstates();
1308
Andi Kleenaa888a72008-07-23 21:27:47 -07001309 gather_bootmem_prealloc();
1310
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001311 report_hugepages();
1312
1313 hugetlb_sysfs_init();
1314
1315 return 0;
1316}
1317module_init(hugetlb_init);
1318
1319/* Should be called on processing a hugepagesz=... option */
1320void __init hugetlb_add_hstate(unsigned order)
1321{
1322 struct hstate *h;
Andi Kleen8faa8b02008-07-23 21:27:48 -07001323 unsigned long i;
1324
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001325 if (size_to_hstate(PAGE_SIZE << order)) {
1326 printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n");
1327 return;
1328 }
1329 BUG_ON(max_hstate >= HUGE_MAX_HSTATE);
1330 BUG_ON(order == 0);
1331 h = &hstates[max_hstate++];
1332 h->order = order;
1333 h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1);
Andi Kleen8faa8b02008-07-23 21:27:48 -07001334 h->nr_huge_pages = 0;
1335 h->free_huge_pages = 0;
1336 for (i = 0; i < MAX_NUMNODES; ++i)
1337 INIT_LIST_HEAD(&h->hugepage_freelists[i]);
1338 h->hugetlb_next_nid = first_node(node_online_map);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001339 snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
1340 huge_page_size(h)/1024);
Andi Kleen8faa8b02008-07-23 21:27:48 -07001341
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001342 parsed_hstate = h;
1343}
1344
Nick Piggine11bfbf2008-07-23 21:27:52 -07001345static int __init hugetlb_nrpages_setup(char *s)
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001346{
1347 unsigned long *mhp;
Andi Kleen8faa8b02008-07-23 21:27:48 -07001348 static unsigned long *last_mhp;
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001349
1350 /*
1351 * !max_hstate means we haven't parsed a hugepagesz= parameter yet,
1352 * so this hugepages= parameter goes to the "default hstate".
1353 */
1354 if (!max_hstate)
1355 mhp = &default_hstate_max_huge_pages;
1356 else
1357 mhp = &parsed_hstate->max_huge_pages;
1358
Andi Kleen8faa8b02008-07-23 21:27:48 -07001359 if (mhp == last_mhp) {
1360 printk(KERN_WARNING "hugepages= specified twice without "
1361 "interleaving hugepagesz=, ignoring\n");
1362 return 1;
1363 }
1364
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001365 if (sscanf(s, "%lu", mhp) <= 0)
1366 *mhp = 0;
1367
Andi Kleen8faa8b02008-07-23 21:27:48 -07001368 /*
1369 * Global state is always initialized later in hugetlb_init.
1370 * But we need to allocate >= MAX_ORDER hstates here early to still
1371 * use the bootmem allocator.
1372 */
1373 if (max_hstate && parsed_hstate->order >= MAX_ORDER)
1374 hugetlb_hstate_alloc_pages(parsed_hstate);
1375
1376 last_mhp = mhp;
1377
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001378 return 1;
1379}
Nick Piggine11bfbf2008-07-23 21:27:52 -07001380__setup("hugepages=", hugetlb_nrpages_setup);
1381
1382static int __init hugetlb_default_setup(char *s)
1383{
1384 default_hstate_size = memparse(s, &s);
1385 return 1;
1386}
1387__setup("default_hugepagesz=", hugetlb_default_setup);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001388
Nishanth Aravamudan8a213462008-07-25 19:44:37 -07001389static unsigned int cpuset_mems_nr(unsigned int *array)
1390{
1391 int node;
1392 unsigned int nr = 0;
1393
1394 for_each_node_mask(node, cpuset_current_mems_allowed)
1395 nr += array[node];
1396
1397 return nr;
1398}
1399
1400#ifdef CONFIG_SYSCTL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001401int hugetlb_sysctl_handler(struct ctl_table *table, int write,
1402 struct file *file, void __user *buffer,
1403 size_t *length, loff_t *ppos)
1404{
Andi Kleene5ff2152008-07-23 21:27:42 -07001405 struct hstate *h = &default_hstate;
1406 unsigned long tmp;
1407
1408 if (!write)
1409 tmp = h->max_huge_pages;
1410
1411 table->data = &tmp;
1412 table->maxlen = sizeof(unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001413 proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
Andi Kleene5ff2152008-07-23 21:27:42 -07001414
1415 if (write)
1416 h->max_huge_pages = set_max_huge_pages(h, tmp);
1417
Linus Torvalds1da177e2005-04-16 15:20:36 -07001418 return 0;
1419}
Mel Gorman396faf02007-07-17 04:03:13 -07001420
1421int hugetlb_treat_movable_handler(struct ctl_table *table, int write,
1422 struct file *file, void __user *buffer,
1423 size_t *length, loff_t *ppos)
1424{
1425 proc_dointvec(table, write, file, buffer, length, ppos);
1426 if (hugepages_treat_as_movable)
1427 htlb_alloc_mask = GFP_HIGHUSER_MOVABLE;
1428 else
1429 htlb_alloc_mask = GFP_HIGHUSER;
1430 return 0;
1431}
1432
Nishanth Aravamudana3d0c6a2008-02-08 04:18:18 -08001433int hugetlb_overcommit_handler(struct ctl_table *table, int write,
1434 struct file *file, void __user *buffer,
1435 size_t *length, loff_t *ppos)
1436{
Andi Kleena5516432008-07-23 21:27:41 -07001437 struct hstate *h = &default_hstate;
Andi Kleene5ff2152008-07-23 21:27:42 -07001438 unsigned long tmp;
1439
1440 if (!write)
1441 tmp = h->nr_overcommit_huge_pages;
1442
1443 table->data = &tmp;
1444 table->maxlen = sizeof(unsigned long);
Nishanth Aravamudana3d0c6a2008-02-08 04:18:18 -08001445 proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
Andi Kleene5ff2152008-07-23 21:27:42 -07001446
1447 if (write) {
1448 spin_lock(&hugetlb_lock);
1449 h->nr_overcommit_huge_pages = tmp;
1450 spin_unlock(&hugetlb_lock);
1451 }
1452
Nishanth Aravamudana3d0c6a2008-02-08 04:18:18 -08001453 return 0;
1454}
1455
Linus Torvalds1da177e2005-04-16 15:20:36 -07001456#endif /* CONFIG_SYSCTL */
1457
1458int hugetlb_report_meminfo(char *buf)
1459{
Andi Kleena5516432008-07-23 21:27:41 -07001460 struct hstate *h = &default_hstate;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001461 return sprintf(buf,
1462 "HugePages_Total: %5lu\n"
1463 "HugePages_Free: %5lu\n"
Chen, Kenneth Wa43a8c32006-06-23 02:03:15 -07001464 "HugePages_Rsvd: %5lu\n"
Adam Litke7893d1d2007-10-16 01:26:18 -07001465 "HugePages_Surp: %5lu\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001466 "Hugepagesize: %5lu kB\n",
Andi Kleena5516432008-07-23 21:27:41 -07001467 h->nr_huge_pages,
1468 h->free_huge_pages,
1469 h->resv_huge_pages,
1470 h->surplus_huge_pages,
1471 1UL << (huge_page_order(h) + PAGE_SHIFT - 10));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001472}
1473
1474int hugetlb_report_node_meminfo(int nid, char *buf)
1475{
Andi Kleena5516432008-07-23 21:27:41 -07001476 struct hstate *h = &default_hstate;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001477 return sprintf(buf,
1478 "Node %d HugePages_Total: %5u\n"
Nishanth Aravamudana1de0912008-03-26 14:37:53 -07001479 "Node %d HugePages_Free: %5u\n"
1480 "Node %d HugePages_Surp: %5u\n",
Andi Kleena5516432008-07-23 21:27:41 -07001481 nid, h->nr_huge_pages_node[nid],
1482 nid, h->free_huge_pages_node[nid],
1483 nid, h->surplus_huge_pages_node[nid]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001484}
1485
Linus Torvalds1da177e2005-04-16 15:20:36 -07001486/* Return the number pages of memory we physically have, in PAGE_SIZE units. */
1487unsigned long hugetlb_total_pages(void)
1488{
Andi Kleena5516432008-07-23 21:27:41 -07001489 struct hstate *h = &default_hstate;
1490 return h->nr_huge_pages * pages_per_huge_page(h);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001491}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001492
Andi Kleena5516432008-07-23 21:27:41 -07001493static int hugetlb_acct_memory(struct hstate *h, long delta)
Mel Gormanfc1b8a72008-07-23 21:27:22 -07001494{
1495 int ret = -ENOMEM;
1496
1497 spin_lock(&hugetlb_lock);
1498 /*
1499 * When cpuset is configured, it breaks the strict hugetlb page
1500 * reservation as the accounting is done on a global variable. Such
1501 * reservation is completely rubbish in the presence of cpuset because
1502 * the reservation is not checked against page availability for the
1503 * current cpuset. Application can still potentially OOM'ed by kernel
1504 * with lack of free htlb page in cpuset that the task is in.
1505 * Attempt to enforce strict accounting with cpuset is almost
1506 * impossible (or too ugly) because cpuset is too fluid that
1507 * task or memory node can be dynamically moved between cpusets.
1508 *
1509 * The change of semantics for shared hugetlb mapping with cpuset is
1510 * undesirable. However, in order to preserve some of the semantics,
1511 * we fall back to check against current free page availability as
1512 * a best attempt and hopefully to minimize the impact of changing
1513 * semantics that cpuset has.
1514 */
1515 if (delta > 0) {
Andi Kleena5516432008-07-23 21:27:41 -07001516 if (gather_surplus_pages(h, delta) < 0)
Mel Gormanfc1b8a72008-07-23 21:27:22 -07001517 goto out;
1518
Andi Kleena5516432008-07-23 21:27:41 -07001519 if (delta > cpuset_mems_nr(h->free_huge_pages_node)) {
1520 return_unused_surplus_pages(h, delta);
Mel Gormanfc1b8a72008-07-23 21:27:22 -07001521 goto out;
1522 }
1523 }
1524
1525 ret = 0;
1526 if (delta < 0)
Andi Kleena5516432008-07-23 21:27:41 -07001527 return_unused_surplus_pages(h, (unsigned long) -delta);
Mel Gormanfc1b8a72008-07-23 21:27:22 -07001528
1529out:
1530 spin_unlock(&hugetlb_lock);
1531 return ret;
1532}
1533
Andy Whitcroft84afd992008-07-23 21:27:32 -07001534static void hugetlb_vm_op_open(struct vm_area_struct *vma)
1535{
1536 struct resv_map *reservations = vma_resv_map(vma);
1537
1538 /*
1539 * This new VMA should share its siblings reservation map if present.
1540 * The VMA will only ever have a valid reservation map pointer where
1541 * it is being copied for another still existing VMA. As that VMA
1542 * has a reference to the reservation map it cannot dissappear until
1543 * after this open call completes. It is therefore safe to take a
1544 * new reference here without additional locking.
1545 */
1546 if (reservations)
1547 kref_get(&reservations->refs);
1548}
1549
Mel Gormana1e78772008-07-23 21:27:23 -07001550static void hugetlb_vm_op_close(struct vm_area_struct *vma)
1551{
Andi Kleena5516432008-07-23 21:27:41 -07001552 struct hstate *h = hstate_vma(vma);
Andy Whitcroft84afd992008-07-23 21:27:32 -07001553 struct resv_map *reservations = vma_resv_map(vma);
1554 unsigned long reserve;
1555 unsigned long start;
1556 unsigned long end;
1557
1558 if (reservations) {
Andi Kleena5516432008-07-23 21:27:41 -07001559 start = vma_hugecache_offset(h, vma, vma->vm_start);
1560 end = vma_hugecache_offset(h, vma, vma->vm_end);
Andy Whitcroft84afd992008-07-23 21:27:32 -07001561
1562 reserve = (end - start) -
1563 region_count(&reservations->regions, start, end);
1564
1565 kref_put(&reservations->refs, resv_map_release);
1566
Adam Litke7251ff782008-07-23 21:27:59 -07001567 if (reserve) {
Andi Kleena5516432008-07-23 21:27:41 -07001568 hugetlb_acct_memory(h, -reserve);
Adam Litke7251ff782008-07-23 21:27:59 -07001569 hugetlb_put_quota(vma->vm_file->f_mapping, reserve);
1570 }
Andy Whitcroft84afd992008-07-23 21:27:32 -07001571 }
Mel Gormana1e78772008-07-23 21:27:23 -07001572}
1573
Linus Torvalds1da177e2005-04-16 15:20:36 -07001574/*
1575 * We cannot handle pagefaults against hugetlb pages at all. They cause
1576 * handle_mm_fault() to try to instantiate regular-sized pages in the
1577 * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get
1578 * this far.
1579 */
Nick Piggind0217ac2007-07-19 01:47:03 -07001580static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001581{
1582 BUG();
Nick Piggind0217ac2007-07-19 01:47:03 -07001583 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001584}
1585
1586struct vm_operations_struct hugetlb_vm_ops = {
Nick Piggind0217ac2007-07-19 01:47:03 -07001587 .fault = hugetlb_vm_op_fault,
Andy Whitcroft84afd992008-07-23 21:27:32 -07001588 .open = hugetlb_vm_op_open,
Mel Gormana1e78772008-07-23 21:27:23 -07001589 .close = hugetlb_vm_op_close,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001590};
1591
David Gibson1e8f8892006-01-06 00:10:44 -08001592static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page,
1593 int writable)
David Gibson63551ae2005-06-21 17:14:44 -07001594{
1595 pte_t entry;
1596
David Gibson1e8f8892006-01-06 00:10:44 -08001597 if (writable) {
David Gibson63551ae2005-06-21 17:14:44 -07001598 entry =
1599 pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
1600 } else {
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07001601 entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot));
David Gibson63551ae2005-06-21 17:14:44 -07001602 }
1603 entry = pte_mkyoung(entry);
1604 entry = pte_mkhuge(entry);
1605
1606 return entry;
1607}
1608
David Gibson1e8f8892006-01-06 00:10:44 -08001609static void set_huge_ptep_writable(struct vm_area_struct *vma,
1610 unsigned long address, pte_t *ptep)
1611{
1612 pte_t entry;
1613
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07001614 entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep)));
1615 if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) {
Benjamin Herrenschmidt8dab5242007-06-16 10:16:12 -07001616 update_mmu_cache(vma, address, entry);
Benjamin Herrenschmidt8dab5242007-06-16 10:16:12 -07001617 }
David Gibson1e8f8892006-01-06 00:10:44 -08001618}
1619
1620
David Gibson63551ae2005-06-21 17:14:44 -07001621int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
1622 struct vm_area_struct *vma)
1623{
1624 pte_t *src_pte, *dst_pte, entry;
1625 struct page *ptepage;
Hugh Dickins1c598272005-10-19 21:23:43 -07001626 unsigned long addr;
David Gibson1e8f8892006-01-06 00:10:44 -08001627 int cow;
Andi Kleena5516432008-07-23 21:27:41 -07001628 struct hstate *h = hstate_vma(vma);
1629 unsigned long sz = huge_page_size(h);
David Gibson1e8f8892006-01-06 00:10:44 -08001630
1631 cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
David Gibson63551ae2005-06-21 17:14:44 -07001632
Andi Kleena5516432008-07-23 21:27:41 -07001633 for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
Hugh Dickinsc74df322005-10-29 18:16:23 -07001634 src_pte = huge_pte_offset(src, addr);
1635 if (!src_pte)
1636 continue;
Andi Kleena5516432008-07-23 21:27:41 -07001637 dst_pte = huge_pte_alloc(dst, addr, sz);
David Gibson63551ae2005-06-21 17:14:44 -07001638 if (!dst_pte)
1639 goto nomem;
Larry Woodmanc5c99422008-01-24 05:49:25 -08001640
1641 /* If the pagetables are shared don't copy or take references */
1642 if (dst_pte == src_pte)
1643 continue;
1644
Hugh Dickinsc74df322005-10-29 18:16:23 -07001645 spin_lock(&dst->page_table_lock);
Nick Piggin46478752008-06-05 22:45:57 -07001646 spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING);
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07001647 if (!huge_pte_none(huge_ptep_get(src_pte))) {
David Gibson1e8f8892006-01-06 00:10:44 -08001648 if (cow)
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07001649 huge_ptep_set_wrprotect(src, addr, src_pte);
1650 entry = huge_ptep_get(src_pte);
Hugh Dickins1c598272005-10-19 21:23:43 -07001651 ptepage = pte_page(entry);
1652 get_page(ptepage);
Hugh Dickins1c598272005-10-19 21:23:43 -07001653 set_huge_pte_at(dst, addr, dst_pte, entry);
1654 }
1655 spin_unlock(&src->page_table_lock);
Hugh Dickinsc74df322005-10-29 18:16:23 -07001656 spin_unlock(&dst->page_table_lock);
David Gibson63551ae2005-06-21 17:14:44 -07001657 }
1658 return 0;
1659
1660nomem:
1661 return -ENOMEM;
1662}
1663
Chen, Kenneth W502717f2006-10-11 01:20:46 -07001664void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001665 unsigned long end, struct page *ref_page)
David Gibson63551ae2005-06-21 17:14:44 -07001666{
1667 struct mm_struct *mm = vma->vm_mm;
1668 unsigned long address;
David Gibsonc7546f82005-08-05 11:59:35 -07001669 pte_t *ptep;
David Gibson63551ae2005-06-21 17:14:44 -07001670 pte_t pte;
1671 struct page *page;
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07001672 struct page *tmp;
Andi Kleena5516432008-07-23 21:27:41 -07001673 struct hstate *h = hstate_vma(vma);
1674 unsigned long sz = huge_page_size(h);
1675
Chen, Kenneth Wc0a499c2006-12-06 20:31:39 -08001676 /*
1677 * A page gathering list, protected by per file i_mmap_lock. The
1678 * lock is used to avoid list corruption from multiple unmapping
1679 * of the same page since we are using page->lru.
1680 */
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07001681 LIST_HEAD(page_list);
David Gibson63551ae2005-06-21 17:14:44 -07001682
1683 WARN_ON(!is_vm_hugetlb_page(vma));
Andi Kleena5516432008-07-23 21:27:41 -07001684 BUG_ON(start & ~huge_page_mask(h));
1685 BUG_ON(end & ~huge_page_mask(h));
David Gibson63551ae2005-06-21 17:14:44 -07001686
Andrea Arcangelicddb8a52008-07-28 15:46:29 -07001687 mmu_notifier_invalidate_range_start(mm, start, end);
Hugh Dickins508034a2005-10-29 18:16:30 -07001688 spin_lock(&mm->page_table_lock);
Andi Kleena5516432008-07-23 21:27:41 -07001689 for (address = start; address < end; address += sz) {
David Gibsonc7546f82005-08-05 11:59:35 -07001690 ptep = huge_pte_offset(mm, address);
Adam Litke4c887262005-10-29 18:16:46 -07001691 if (!ptep)
David Gibsonc7546f82005-08-05 11:59:35 -07001692 continue;
1693
Chen, Kenneth W39dde652006-12-06 20:32:03 -08001694 if (huge_pmd_unshare(mm, &address, ptep))
1695 continue;
1696
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001697 /*
1698 * If a reference page is supplied, it is because a specific
1699 * page is being unmapped, not a range. Ensure the page we
1700 * are about to unmap is the actual page of interest.
1701 */
1702 if (ref_page) {
1703 pte = huge_ptep_get(ptep);
1704 if (huge_pte_none(pte))
1705 continue;
1706 page = pte_page(pte);
1707 if (page != ref_page)
1708 continue;
1709
1710 /*
1711 * Mark the VMA as having unmapped its page so that
1712 * future faults in this VMA will fail rather than
1713 * looking like data was lost
1714 */
1715 set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED);
1716 }
1717
David Gibsonc7546f82005-08-05 11:59:35 -07001718 pte = huge_ptep_get_and_clear(mm, address, ptep);
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07001719 if (huge_pte_none(pte))
David Gibson63551ae2005-06-21 17:14:44 -07001720 continue;
David Gibsonc7546f82005-08-05 11:59:35 -07001721
David Gibson63551ae2005-06-21 17:14:44 -07001722 page = pte_page(pte);
Ken Chen6649a382007-02-08 14:20:27 -08001723 if (pte_dirty(pte))
1724 set_page_dirty(page);
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07001725 list_add(&page->lru, &page_list);
David Gibson63551ae2005-06-21 17:14:44 -07001726 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001727 spin_unlock(&mm->page_table_lock);
Hugh Dickins508034a2005-10-29 18:16:30 -07001728 flush_tlb_range(vma, start, end);
Andrea Arcangelicddb8a52008-07-28 15:46:29 -07001729 mmu_notifier_invalidate_range_end(mm, start, end);
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07001730 list_for_each_entry_safe(page, tmp, &page_list, lru) {
1731 list_del(&page->lru);
1732 put_page(page);
1733 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001734}
David Gibson63551ae2005-06-21 17:14:44 -07001735
Chen, Kenneth W502717f2006-10-11 01:20:46 -07001736void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001737 unsigned long end, struct page *ref_page)
Chen, Kenneth W502717f2006-10-11 01:20:46 -07001738{
Andi Kleena137e1c2008-07-23 21:27:43 -07001739 spin_lock(&vma->vm_file->f_mapping->i_mmap_lock);
1740 __unmap_hugepage_range(vma, start, end, ref_page);
1741 spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock);
Chen, Kenneth W502717f2006-10-11 01:20:46 -07001742}
1743
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001744/*
1745 * This is called when the original mapper is failing to COW a MAP_PRIVATE
1746 * mappping it owns the reserve page for. The intention is to unmap the page
1747 * from other VMAs and let the children be SIGKILLed if they are faulting the
1748 * same region.
1749 */
1750int unmap_ref_private(struct mm_struct *mm,
1751 struct vm_area_struct *vma,
1752 struct page *page,
1753 unsigned long address)
1754{
1755 struct vm_area_struct *iter_vma;
1756 struct address_space *mapping;
1757 struct prio_tree_iter iter;
1758 pgoff_t pgoff;
1759
1760 /*
1761 * vm_pgoff is in PAGE_SIZE units, hence the different calculation
1762 * from page cache lookup which is in HPAGE_SIZE units.
1763 */
1764 address = address & huge_page_mask(hstate_vma(vma));
1765 pgoff = ((address - vma->vm_start) >> PAGE_SHIFT)
1766 + (vma->vm_pgoff >> PAGE_SHIFT);
1767 mapping = (struct address_space *)page_private(page);
1768
1769 vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
1770 /* Do not unmap the current VMA */
1771 if (iter_vma == vma)
1772 continue;
1773
1774 /*
1775 * Unmap the page from other VMAs without their own reserves.
1776 * They get marked to be SIGKILLed if they fault in these
1777 * areas. This is because a future no-page fault on this VMA
1778 * could insert a zeroed page instead of the data existing
1779 * from the time of fork. This would look like data corruption
1780 */
1781 if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER))
1782 unmap_hugepage_range(iter_vma,
1783 address, address + HPAGE_SIZE,
1784 page);
1785 }
1786
1787 return 1;
1788}
1789
David Gibson1e8f8892006-01-06 00:10:44 -08001790static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001791 unsigned long address, pte_t *ptep, pte_t pte,
1792 struct page *pagecache_page)
David Gibson1e8f8892006-01-06 00:10:44 -08001793{
Andi Kleena5516432008-07-23 21:27:41 -07001794 struct hstate *h = hstate_vma(vma);
David Gibson1e8f8892006-01-06 00:10:44 -08001795 struct page *old_page, *new_page;
David Gibson79ac6ba2006-03-22 00:08:51 -08001796 int avoidcopy;
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001797 int outside_reserve = 0;
David Gibson1e8f8892006-01-06 00:10:44 -08001798
1799 old_page = pte_page(pte);
1800
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001801retry_avoidcopy:
David Gibson1e8f8892006-01-06 00:10:44 -08001802 /* If no-one else is actually using this page, avoid the copy
1803 * and just make the page writable */
1804 avoidcopy = (page_count(old_page) == 1);
1805 if (avoidcopy) {
1806 set_huge_ptep_writable(vma, address, ptep);
Nick Piggin83c54072007-07-19 01:47:05 -07001807 return 0;
David Gibson1e8f8892006-01-06 00:10:44 -08001808 }
1809
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001810 /*
1811 * If the process that created a MAP_PRIVATE mapping is about to
1812 * perform a COW due to a shared page count, attempt to satisfy
1813 * the allocation without using the existing reserves. The pagecache
1814 * page is used to determine if the reserve at this address was
1815 * consumed or not. If reserves were used, a partial faulted mapping
1816 * at the time of fork() could consume its reserves on COW instead
1817 * of the full address range.
1818 */
1819 if (!(vma->vm_flags & VM_SHARED) &&
1820 is_vma_resv_set(vma, HPAGE_RESV_OWNER) &&
1821 old_page != pagecache_page)
1822 outside_reserve = 1;
1823
David Gibson1e8f8892006-01-06 00:10:44 -08001824 page_cache_get(old_page);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001825 new_page = alloc_huge_page(vma, address, outside_reserve);
David Gibson1e8f8892006-01-06 00:10:44 -08001826
Adam Litke2fc39ce2007-11-14 16:59:39 -08001827 if (IS_ERR(new_page)) {
David Gibson1e8f8892006-01-06 00:10:44 -08001828 page_cache_release(old_page);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001829
1830 /*
1831 * If a process owning a MAP_PRIVATE mapping fails to COW,
1832 * it is due to references held by a child and an insufficient
1833 * huge page pool. To guarantee the original mappers
1834 * reliability, unmap the page from child processes. The child
1835 * may get SIGKILLed if it later faults.
1836 */
1837 if (outside_reserve) {
1838 BUG_ON(huge_pte_none(pte));
1839 if (unmap_ref_private(mm, vma, old_page, address)) {
1840 BUG_ON(page_count(old_page) != 1);
1841 BUG_ON(huge_pte_none(pte));
1842 goto retry_avoidcopy;
1843 }
1844 WARN_ON_ONCE(1);
1845 }
1846
Adam Litke2fc39ce2007-11-14 16:59:39 -08001847 return -PTR_ERR(new_page);
David Gibson1e8f8892006-01-06 00:10:44 -08001848 }
1849
1850 spin_unlock(&mm->page_table_lock);
Atsushi Nemoto9de455b2006-12-12 17:14:55 +00001851 copy_huge_page(new_page, old_page, address, vma);
Nick Piggin0ed361d2008-02-04 22:29:34 -08001852 __SetPageUptodate(new_page);
David Gibson1e8f8892006-01-06 00:10:44 -08001853 spin_lock(&mm->page_table_lock);
1854
Andi Kleena5516432008-07-23 21:27:41 -07001855 ptep = huge_pte_offset(mm, address & huge_page_mask(h));
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07001856 if (likely(pte_same(huge_ptep_get(ptep), pte))) {
David Gibson1e8f8892006-01-06 00:10:44 -08001857 /* Break COW */
Gerald Schaefer8fe627e2008-04-28 02:13:28 -07001858 huge_ptep_clear_flush(vma, address, ptep);
David Gibson1e8f8892006-01-06 00:10:44 -08001859 set_huge_pte_at(mm, address, ptep,
1860 make_huge_pte(vma, new_page, 1));
1861 /* Make the old page be freed below */
1862 new_page = old_page;
1863 }
1864 page_cache_release(new_page);
1865 page_cache_release(old_page);
Nick Piggin83c54072007-07-19 01:47:05 -07001866 return 0;
David Gibson1e8f8892006-01-06 00:10:44 -08001867}
1868
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001869/* Return the pagecache page at a given address within a VMA */
Andi Kleena5516432008-07-23 21:27:41 -07001870static struct page *hugetlbfs_pagecache_page(struct hstate *h,
1871 struct vm_area_struct *vma, unsigned long address)
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001872{
1873 struct address_space *mapping;
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -07001874 pgoff_t idx;
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001875
1876 mapping = vma->vm_file->f_mapping;
Andi Kleena5516432008-07-23 21:27:41 -07001877 idx = vma_hugecache_offset(h, vma, address);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001878
1879 return find_lock_page(mapping, idx);
1880}
1881
Robert P. J. Daya1ed3dd2007-07-17 04:03:33 -07001882static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
David Gibson1e8f8892006-01-06 00:10:44 -08001883 unsigned long address, pte_t *ptep, int write_access)
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01001884{
Andi Kleena5516432008-07-23 21:27:41 -07001885 struct hstate *h = hstate_vma(vma);
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01001886 int ret = VM_FAULT_SIGBUS;
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -07001887 pgoff_t idx;
Adam Litke4c887262005-10-29 18:16:46 -07001888 unsigned long size;
Adam Litke4c887262005-10-29 18:16:46 -07001889 struct page *page;
1890 struct address_space *mapping;
David Gibson1e8f8892006-01-06 00:10:44 -08001891 pte_t new_pte;
Adam Litke4c887262005-10-29 18:16:46 -07001892
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001893 /*
1894 * Currently, we are forced to kill the process in the event the
1895 * original mapper has unmapped pages from the child due to a failed
1896 * COW. Warn that such a situation has occured as it may not be obvious
1897 */
1898 if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) {
1899 printk(KERN_WARNING
1900 "PID %d killed due to inadequate hugepage pool\n",
1901 current->pid);
1902 return ret;
1903 }
1904
Adam Litke4c887262005-10-29 18:16:46 -07001905 mapping = vma->vm_file->f_mapping;
Andi Kleena5516432008-07-23 21:27:41 -07001906 idx = vma_hugecache_offset(h, vma, address);
Adam Litke4c887262005-10-29 18:16:46 -07001907
1908 /*
1909 * Use page lock to guard against racing truncation
1910 * before we get page_table_lock.
1911 */
Christoph Lameter6bda6662006-01-06 00:10:49 -08001912retry:
1913 page = find_lock_page(mapping, idx);
1914 if (!page) {
Andi Kleena5516432008-07-23 21:27:41 -07001915 size = i_size_read(mapping->host) >> huge_page_shift(h);
Hugh Dickinsebed4bf2006-10-28 10:38:43 -07001916 if (idx >= size)
1917 goto out;
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001918 page = alloc_huge_page(vma, address, 0);
Adam Litke2fc39ce2007-11-14 16:59:39 -08001919 if (IS_ERR(page)) {
1920 ret = -PTR_ERR(page);
Christoph Lameter6bda6662006-01-06 00:10:49 -08001921 goto out;
1922 }
Andi Kleena5516432008-07-23 21:27:41 -07001923 clear_huge_page(page, address, huge_page_size(h));
Nick Piggin0ed361d2008-02-04 22:29:34 -08001924 __SetPageUptodate(page);
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01001925
Christoph Lameter6bda6662006-01-06 00:10:49 -08001926 if (vma->vm_flags & VM_SHARED) {
1927 int err;
Ken Chen45c682a2007-11-14 16:59:44 -08001928 struct inode *inode = mapping->host;
Christoph Lameter6bda6662006-01-06 00:10:49 -08001929
1930 err = add_to_page_cache(page, mapping, idx, GFP_KERNEL);
1931 if (err) {
1932 put_page(page);
Christoph Lameter6bda6662006-01-06 00:10:49 -08001933 if (err == -EEXIST)
1934 goto retry;
1935 goto out;
1936 }
Ken Chen45c682a2007-11-14 16:59:44 -08001937
1938 spin_lock(&inode->i_lock);
Andi Kleena5516432008-07-23 21:27:41 -07001939 inode->i_blocks += blocks_per_huge_page(h);
Ken Chen45c682a2007-11-14 16:59:44 -08001940 spin_unlock(&inode->i_lock);
Christoph Lameter6bda6662006-01-06 00:10:49 -08001941 } else
1942 lock_page(page);
1943 }
David Gibson1e8f8892006-01-06 00:10:44 -08001944
Andy Whitcroft57303d82008-08-12 15:08:47 -07001945 /*
1946 * If we are going to COW a private mapping later, we examine the
1947 * pending reservations for this page now. This will ensure that
1948 * any allocations necessary to record that reservation occur outside
1949 * the spinlock.
1950 */
1951 if (write_access && !(vma->vm_flags & VM_SHARED))
Andy Whitcroft2b267362008-08-12 15:08:49 -07001952 if (vma_needs_reservation(h, vma, address) < 0) {
1953 ret = VM_FAULT_OOM;
1954 goto backout_unlocked;
1955 }
Andy Whitcroft57303d82008-08-12 15:08:47 -07001956
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01001957 spin_lock(&mm->page_table_lock);
Andi Kleena5516432008-07-23 21:27:41 -07001958 size = i_size_read(mapping->host) >> huge_page_shift(h);
Adam Litke4c887262005-10-29 18:16:46 -07001959 if (idx >= size)
1960 goto backout;
1961
Nick Piggin83c54072007-07-19 01:47:05 -07001962 ret = 0;
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07001963 if (!huge_pte_none(huge_ptep_get(ptep)))
Adam Litke4c887262005-10-29 18:16:46 -07001964 goto backout;
1965
David Gibson1e8f8892006-01-06 00:10:44 -08001966 new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE)
1967 && (vma->vm_flags & VM_SHARED)));
1968 set_huge_pte_at(mm, address, ptep, new_pte);
1969
1970 if (write_access && !(vma->vm_flags & VM_SHARED)) {
1971 /* Optimization, do the COW without a second fault */
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001972 ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page);
David Gibson1e8f8892006-01-06 00:10:44 -08001973 }
1974
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01001975 spin_unlock(&mm->page_table_lock);
Adam Litke4c887262005-10-29 18:16:46 -07001976 unlock_page(page);
1977out:
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01001978 return ret;
Adam Litke4c887262005-10-29 18:16:46 -07001979
1980backout:
1981 spin_unlock(&mm->page_table_lock);
Andy Whitcroft2b267362008-08-12 15:08:49 -07001982backout_unlocked:
Adam Litke4c887262005-10-29 18:16:46 -07001983 unlock_page(page);
1984 put_page(page);
1985 goto out;
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01001986}
1987
Adam Litke86e52162006-01-06 00:10:43 -08001988int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
1989 unsigned long address, int write_access)
1990{
1991 pte_t *ptep;
1992 pte_t entry;
David Gibson1e8f8892006-01-06 00:10:44 -08001993 int ret;
Andy Whitcroft57303d82008-08-12 15:08:47 -07001994 struct page *pagecache_page = NULL;
David Gibson3935baa2006-03-22 00:08:53 -08001995 static DEFINE_MUTEX(hugetlb_instantiation_mutex);
Andi Kleena5516432008-07-23 21:27:41 -07001996 struct hstate *h = hstate_vma(vma);
Adam Litke86e52162006-01-06 00:10:43 -08001997
Andi Kleena5516432008-07-23 21:27:41 -07001998 ptep = huge_pte_alloc(mm, address, huge_page_size(h));
Adam Litke86e52162006-01-06 00:10:43 -08001999 if (!ptep)
2000 return VM_FAULT_OOM;
2001
David Gibson3935baa2006-03-22 00:08:53 -08002002 /*
2003 * Serialize hugepage allocation and instantiation, so that we don't
2004 * get spurious allocation failures if two CPUs race to instantiate
2005 * the same page in the page cache.
2006 */
2007 mutex_lock(&hugetlb_instantiation_mutex);
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002008 entry = huge_ptep_get(ptep);
2009 if (huge_pte_none(entry)) {
David Gibson3935baa2006-03-22 00:08:53 -08002010 ret = hugetlb_no_page(mm, vma, address, ptep, write_access);
David Gibsonb4d1d992008-10-15 22:01:11 -07002011 goto out_mutex;
David Gibson3935baa2006-03-22 00:08:53 -08002012 }
Adam Litke86e52162006-01-06 00:10:43 -08002013
Nick Piggin83c54072007-07-19 01:47:05 -07002014 ret = 0;
David Gibson1e8f8892006-01-06 00:10:44 -08002015
Andy Whitcroft57303d82008-08-12 15:08:47 -07002016 /*
2017 * If we are going to COW the mapping later, we examine the pending
2018 * reservations for this page now. This will ensure that any
2019 * allocations necessary to record that reservation occur outside the
2020 * spinlock. For private mappings, we also lookup the pagecache
2021 * page now as it is used to determine if a reservation has been
2022 * consumed.
2023 */
2024 if (write_access && !pte_write(entry)) {
Andy Whitcroft2b267362008-08-12 15:08:49 -07002025 if (vma_needs_reservation(h, vma, address) < 0) {
2026 ret = VM_FAULT_OOM;
David Gibsonb4d1d992008-10-15 22:01:11 -07002027 goto out_mutex;
Andy Whitcroft2b267362008-08-12 15:08:49 -07002028 }
Andy Whitcroft57303d82008-08-12 15:08:47 -07002029
2030 if (!(vma->vm_flags & VM_SHARED))
2031 pagecache_page = hugetlbfs_pagecache_page(h,
2032 vma, address);
2033 }
2034
David Gibson1e8f8892006-01-06 00:10:44 -08002035 spin_lock(&mm->page_table_lock);
2036 /* Check for a racing update before calling hugetlb_cow */
David Gibsonb4d1d992008-10-15 22:01:11 -07002037 if (unlikely(!pte_same(entry, huge_ptep_get(ptep))))
2038 goto out_page_table_lock;
2039
2040
2041 if (write_access) {
2042 if (!pte_write(entry)) {
Andy Whitcroft57303d82008-08-12 15:08:47 -07002043 ret = hugetlb_cow(mm, vma, address, ptep, entry,
2044 pagecache_page);
David Gibsonb4d1d992008-10-15 22:01:11 -07002045 goto out_page_table_lock;
2046 }
2047 entry = pte_mkdirty(entry);
2048 }
2049 entry = pte_mkyoung(entry);
2050 if (huge_ptep_set_access_flags(vma, address, ptep, entry, write_access))
2051 update_mmu_cache(vma, address, entry);
2052
2053out_page_table_lock:
David Gibson1e8f8892006-01-06 00:10:44 -08002054 spin_unlock(&mm->page_table_lock);
Andy Whitcroft57303d82008-08-12 15:08:47 -07002055
2056 if (pagecache_page) {
2057 unlock_page(pagecache_page);
2058 put_page(pagecache_page);
2059 }
2060
David Gibsonb4d1d992008-10-15 22:01:11 -07002061out_mutex:
David Gibson3935baa2006-03-22 00:08:53 -08002062 mutex_unlock(&hugetlb_instantiation_mutex);
David Gibson1e8f8892006-01-06 00:10:44 -08002063
2064 return ret;
Adam Litke86e52162006-01-06 00:10:43 -08002065}
2066
Andi Kleenceb86872008-07-23 21:27:50 -07002067/* Can be overriden by architectures */
2068__attribute__((weak)) struct page *
2069follow_huge_pud(struct mm_struct *mm, unsigned long address,
2070 pud_t *pud, int write)
2071{
2072 BUG();
2073 return NULL;
2074}
2075
David Gibson63551ae2005-06-21 17:14:44 -07002076int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
2077 struct page **pages, struct vm_area_struct **vmas,
Adam Litke5b23dbe2007-11-14 16:59:33 -08002078 unsigned long *position, int *length, int i,
2079 int write)
David Gibson63551ae2005-06-21 17:14:44 -07002080{
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002081 unsigned long pfn_offset;
2082 unsigned long vaddr = *position;
David Gibson63551ae2005-06-21 17:14:44 -07002083 int remainder = *length;
Andi Kleena5516432008-07-23 21:27:41 -07002084 struct hstate *h = hstate_vma(vma);
David Gibson63551ae2005-06-21 17:14:44 -07002085
Hugh Dickins1c598272005-10-19 21:23:43 -07002086 spin_lock(&mm->page_table_lock);
David Gibson63551ae2005-06-21 17:14:44 -07002087 while (vaddr < vma->vm_end && remainder) {
Adam Litke4c887262005-10-29 18:16:46 -07002088 pte_t *pte;
2089 struct page *page;
2090
2091 /*
2092 * Some archs (sparc64, sh*) have multiple pte_ts to
2093 * each hugepage. We have to make * sure we get the
2094 * first, for the page indexing below to work.
2095 */
Andi Kleena5516432008-07-23 21:27:41 -07002096 pte = huge_pte_offset(mm, vaddr & huge_page_mask(h));
Adam Litke4c887262005-10-29 18:16:46 -07002097
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002098 if (!pte || huge_pte_none(huge_ptep_get(pte)) ||
2099 (write && !pte_write(huge_ptep_get(pte)))) {
Adam Litke4c887262005-10-29 18:16:46 -07002100 int ret;
2101
2102 spin_unlock(&mm->page_table_lock);
Adam Litke5b23dbe2007-11-14 16:59:33 -08002103 ret = hugetlb_fault(mm, vma, vaddr, write);
Adam Litke4c887262005-10-29 18:16:46 -07002104 spin_lock(&mm->page_table_lock);
Adam Litkea89182c2007-08-22 14:01:51 -07002105 if (!(ret & VM_FAULT_ERROR))
Adam Litke4c887262005-10-29 18:16:46 -07002106 continue;
2107
2108 remainder = 0;
2109 if (!i)
2110 i = -EFAULT;
2111 break;
2112 }
David Gibson63551ae2005-06-21 17:14:44 -07002113
Andi Kleena5516432008-07-23 21:27:41 -07002114 pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT;
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002115 page = pte_page(huge_ptep_get(pte));
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002116same_page:
Chen, Kenneth Wd6692182006-03-31 02:29:57 -08002117 if (pages) {
2118 get_page(page);
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002119 pages[i] = page + pfn_offset;
Chen, Kenneth Wd6692182006-03-31 02:29:57 -08002120 }
David Gibson63551ae2005-06-21 17:14:44 -07002121
2122 if (vmas)
2123 vmas[i] = vma;
2124
2125 vaddr += PAGE_SIZE;
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002126 ++pfn_offset;
David Gibson63551ae2005-06-21 17:14:44 -07002127 --remainder;
2128 ++i;
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002129 if (vaddr < vma->vm_end && remainder &&
Andi Kleena5516432008-07-23 21:27:41 -07002130 pfn_offset < pages_per_huge_page(h)) {
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002131 /*
2132 * We use pfn_offset to avoid touching the pageframes
2133 * of this compound page.
2134 */
2135 goto same_page;
2136 }
David Gibson63551ae2005-06-21 17:14:44 -07002137 }
Hugh Dickins1c598272005-10-19 21:23:43 -07002138 spin_unlock(&mm->page_table_lock);
David Gibson63551ae2005-06-21 17:14:44 -07002139 *length = remainder;
2140 *position = vaddr;
2141
2142 return i;
2143}
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002144
2145void hugetlb_change_protection(struct vm_area_struct *vma,
2146 unsigned long address, unsigned long end, pgprot_t newprot)
2147{
2148 struct mm_struct *mm = vma->vm_mm;
2149 unsigned long start = address;
2150 pte_t *ptep;
2151 pte_t pte;
Andi Kleena5516432008-07-23 21:27:41 -07002152 struct hstate *h = hstate_vma(vma);
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002153
2154 BUG_ON(address >= end);
2155 flush_cache_range(vma, address, end);
2156
Chen, Kenneth W39dde652006-12-06 20:32:03 -08002157 spin_lock(&vma->vm_file->f_mapping->i_mmap_lock);
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002158 spin_lock(&mm->page_table_lock);
Andi Kleena5516432008-07-23 21:27:41 -07002159 for (; address < end; address += huge_page_size(h)) {
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002160 ptep = huge_pte_offset(mm, address);
2161 if (!ptep)
2162 continue;
Chen, Kenneth W39dde652006-12-06 20:32:03 -08002163 if (huge_pmd_unshare(mm, &address, ptep))
2164 continue;
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002165 if (!huge_pte_none(huge_ptep_get(ptep))) {
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002166 pte = huge_ptep_get_and_clear(mm, address, ptep);
2167 pte = pte_mkhuge(pte_modify(pte, newprot));
2168 set_huge_pte_at(mm, address, ptep, pte);
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002169 }
2170 }
2171 spin_unlock(&mm->page_table_lock);
Chen, Kenneth W39dde652006-12-06 20:32:03 -08002172 spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock);
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002173
2174 flush_tlb_range(vma, start, end);
2175}
2176
Mel Gormana1e78772008-07-23 21:27:23 -07002177int hugetlb_reserve_pages(struct inode *inode,
2178 long from, long to,
2179 struct vm_area_struct *vma)
Adam Litkee4e574b2007-10-16 01:26:19 -07002180{
2181 long ret, chg;
Andi Kleena5516432008-07-23 21:27:41 -07002182 struct hstate *h = hstate_inode(inode);
Adam Litkee4e574b2007-10-16 01:26:19 -07002183
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -07002184 if (vma && vma->vm_flags & VM_NORESERVE)
2185 return 0;
2186
Mel Gormana1e78772008-07-23 21:27:23 -07002187 /*
2188 * Shared mappings base their reservation on the number of pages that
2189 * are already allocated on behalf of the file. Private mappings need
2190 * to reserve the full area even if read-only as mprotect() may be
2191 * called to make the mapping read-write. Assume !vma is a shm mapping
2192 */
2193 if (!vma || vma->vm_flags & VM_SHARED)
2194 chg = region_chg(&inode->i_mapping->private_list, from, to);
2195 else {
Andy Whitcroft84afd992008-07-23 21:27:32 -07002196 struct resv_map *resv_map = resv_map_alloc();
2197 if (!resv_map)
2198 return -ENOMEM;
2199
Mel Gormana1e78772008-07-23 21:27:23 -07002200 chg = to - from;
Andy Whitcroft84afd992008-07-23 21:27:32 -07002201
2202 set_vma_resv_map(vma, resv_map);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002203 set_vma_resv_flags(vma, HPAGE_RESV_OWNER);
Mel Gormana1e78772008-07-23 21:27:23 -07002204 }
2205
Adam Litkee4e574b2007-10-16 01:26:19 -07002206 if (chg < 0)
2207 return chg;
Ken Chen8a630112007-05-09 02:33:34 -07002208
Adam Litke90d8b7e2007-11-14 16:59:42 -08002209 if (hugetlb_get_quota(inode->i_mapping, chg))
2210 return -ENOSPC;
Andi Kleena5516432008-07-23 21:27:41 -07002211 ret = hugetlb_acct_memory(h, chg);
Ken Chen68842c92008-01-14 00:55:19 -08002212 if (ret < 0) {
2213 hugetlb_put_quota(inode->i_mapping, chg);
Chen, Kenneth Wa43a8c32006-06-23 02:03:15 -07002214 return ret;
Ken Chen68842c92008-01-14 00:55:19 -08002215 }
Mel Gormana1e78772008-07-23 21:27:23 -07002216 if (!vma || vma->vm_flags & VM_SHARED)
2217 region_add(&inode->i_mapping->private_list, from, to);
Chen, Kenneth Wa43a8c32006-06-23 02:03:15 -07002218 return 0;
2219}
2220
2221void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed)
2222{
Andi Kleena5516432008-07-23 21:27:41 -07002223 struct hstate *h = hstate_inode(inode);
Chen, Kenneth Wa43a8c32006-06-23 02:03:15 -07002224 long chg = region_truncate(&inode->i_mapping->private_list, offset);
Ken Chen45c682a2007-11-14 16:59:44 -08002225
2226 spin_lock(&inode->i_lock);
Andi Kleena5516432008-07-23 21:27:41 -07002227 inode->i_blocks -= blocks_per_huge_page(h);
Ken Chen45c682a2007-11-14 16:59:44 -08002228 spin_unlock(&inode->i_lock);
2229
Adam Litke90d8b7e2007-11-14 16:59:42 -08002230 hugetlb_put_quota(inode->i_mapping, (chg - freed));
Andi Kleena5516432008-07-23 21:27:41 -07002231 hugetlb_acct_memory(h, -(chg - freed));
Chen, Kenneth Wa43a8c32006-06-23 02:03:15 -07002232}