blob: 0c74c14dd2f7a367de4b034c0c5e0d870c02b905 [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>
12#include <linux/nodemask.h>
David Gibson63551ae2005-06-21 17:14:44 -070013#include <linux/pagemap.h>
Christoph Lameter5da7ca82006-01-06 00:10:46 -080014#include <linux/mempolicy.h>
Christoph Lameteraea47ff2006-01-08 01:00:57 -080015#include <linux/cpuset.h>
David Gibson3935baa2006-03-22 00:08:53 -080016#include <linux/mutex.h>
Andi Kleenaa888a72008-07-23 21:27:47 -070017#include <linux/bootmem.h>
Nishanth Aravamudana3437872008-07-23 21:27:44 -070018#include <linux/sysfs.h>
Christoph Lameter5da7ca82006-01-06 00:10:46 -080019
David Gibson63551ae2005-06-21 17:14:44 -070020#include <asm/page.h>
21#include <asm/pgtable.h>
22
23#include <linux/hugetlb.h>
Nick Piggin7835e982006-03-22 00:08:40 -080024#include "internal.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
26const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
Mel Gorman396faf02007-07-17 04:03:13 -070027static gfp_t htlb_alloc_mask = GFP_HIGHUSER;
28unsigned long hugepages_treat_as_movable;
Andi Kleena5516432008-07-23 21:27:41 -070029
Andi Kleene5ff2152008-07-23 21:27:42 -070030static int max_hstate;
31unsigned int default_hstate_idx;
32struct hstate hstates[HUGE_MAX_HSTATE];
33
34/* for command line parsing */
35static struct hstate * __initdata parsed_hstate;
36static unsigned long __initdata default_hstate_max_huge_pages;
37
38#define for_each_hstate(h) \
39 for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++)
Mel Gorman396faf02007-07-17 04:03:13 -070040
David Gibson3935baa2006-03-22 00:08:53 -080041/*
42 * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages
43 */
44static DEFINE_SPINLOCK(hugetlb_lock);
Eric Paris0bd0f9f2005-11-21 21:32:28 -080045
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -070046/*
Andy Whitcroft96822902008-07-23 21:27:29 -070047 * Region tracking -- allows tracking of reservations and instantiated pages
48 * across the pages in a mapping.
Andy Whitcroft84afd992008-07-23 21:27:32 -070049 *
50 * The region data structures are protected by a combination of the mmap_sem
51 * and the hugetlb_instantion_mutex. To access or modify a region the caller
52 * must either hold the mmap_sem for write, or the mmap_sem for read and
53 * the hugetlb_instantiation mutex:
54 *
55 * down_write(&mm->mmap_sem);
56 * or
57 * down_read(&mm->mmap_sem);
58 * mutex_lock(&hugetlb_instantiation_mutex);
Andy Whitcroft96822902008-07-23 21:27:29 -070059 */
60struct file_region {
61 struct list_head link;
62 long from;
63 long to;
64};
65
66static long region_add(struct list_head *head, long f, long t)
67{
68 struct file_region *rg, *nrg, *trg;
69
70 /* Locate the region we are either in or before. */
71 list_for_each_entry(rg, head, link)
72 if (f <= rg->to)
73 break;
74
75 /* Round our left edge to the current segment if it encloses us. */
76 if (f > rg->from)
77 f = rg->from;
78
79 /* Check for and consume any regions we now overlap with. */
80 nrg = rg;
81 list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
82 if (&rg->link == head)
83 break;
84 if (rg->from > t)
85 break;
86
87 /* If this area reaches higher then extend our area to
88 * include it completely. If this is not the first area
89 * which we intend to reuse, free it. */
90 if (rg->to > t)
91 t = rg->to;
92 if (rg != nrg) {
93 list_del(&rg->link);
94 kfree(rg);
95 }
96 }
97 nrg->from = f;
98 nrg->to = t;
99 return 0;
100}
101
102static long region_chg(struct list_head *head, long f, long t)
103{
104 struct file_region *rg, *nrg;
105 long chg = 0;
106
107 /* Locate the region we are before or in. */
108 list_for_each_entry(rg, head, link)
109 if (f <= rg->to)
110 break;
111
112 /* If we are below the current region then a new region is required.
113 * Subtle, allocate a new region at the position but make it zero
114 * size such that we can guarantee to record the reservation. */
115 if (&rg->link == head || t < rg->from) {
116 nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
117 if (!nrg)
118 return -ENOMEM;
119 nrg->from = f;
120 nrg->to = f;
121 INIT_LIST_HEAD(&nrg->link);
122 list_add(&nrg->link, rg->link.prev);
123
124 return t - f;
125 }
126
127 /* Round our left edge to the current segment if it encloses us. */
128 if (f > rg->from)
129 f = rg->from;
130 chg = t - f;
131
132 /* Check for and consume any regions we now overlap with. */
133 list_for_each_entry(rg, rg->link.prev, link) {
134 if (&rg->link == head)
135 break;
136 if (rg->from > t)
137 return chg;
138
139 /* We overlap with this area, if it extends futher than
140 * us then we must extend ourselves. Account for its
141 * existing reservation. */
142 if (rg->to > t) {
143 chg += rg->to - t;
144 t = rg->to;
145 }
146 chg -= rg->to - rg->from;
147 }
148 return chg;
149}
150
151static long region_truncate(struct list_head *head, long end)
152{
153 struct file_region *rg, *trg;
154 long chg = 0;
155
156 /* Locate the region we are either in or before. */
157 list_for_each_entry(rg, head, link)
158 if (end <= rg->to)
159 break;
160 if (&rg->link == head)
161 return 0;
162
163 /* If we are in the middle of a region then adjust it. */
164 if (end > rg->from) {
165 chg = rg->to - end;
166 rg->to = end;
167 rg = list_entry(rg->link.next, typeof(*rg), link);
168 }
169
170 /* Drop any remaining regions. */
171 list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
172 if (&rg->link == head)
173 break;
174 chg += rg->to - rg->from;
175 list_del(&rg->link);
176 kfree(rg);
177 }
178 return chg;
179}
180
Andy Whitcroft84afd992008-07-23 21:27:32 -0700181static long region_count(struct list_head *head, long f, long t)
182{
183 struct file_region *rg;
184 long chg = 0;
185
186 /* Locate each segment we overlap with, and count that overlap. */
187 list_for_each_entry(rg, head, link) {
188 int seg_from;
189 int seg_to;
190
191 if (rg->to <= f)
192 continue;
193 if (rg->from >= t)
194 break;
195
196 seg_from = max(rg->from, f);
197 seg_to = min(rg->to, t);
198
199 chg += seg_to - seg_from;
200 }
201
202 return chg;
203}
204
Andy Whitcroft96822902008-07-23 21:27:29 -0700205/*
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700206 * Convert the address within this vma to the page offset within
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700207 * the mapping, in pagecache page units; huge pages here.
208 */
Andi Kleena5516432008-07-23 21:27:41 -0700209static pgoff_t vma_hugecache_offset(struct hstate *h,
210 struct vm_area_struct *vma, unsigned long address)
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700211{
Andi Kleena5516432008-07-23 21:27:41 -0700212 return ((address - vma->vm_start) >> huge_page_shift(h)) +
213 (vma->vm_pgoff >> huge_page_order(h));
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700214}
215
Andy Whitcroft84afd992008-07-23 21:27:32 -0700216/*
217 * Flags for MAP_PRIVATE reservations. These are stored in the bottom
218 * bits of the reservation map pointer, which are always clear due to
219 * alignment.
220 */
221#define HPAGE_RESV_OWNER (1UL << 0)
222#define HPAGE_RESV_UNMAPPED (1UL << 1)
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700223#define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED)
Andy Whitcroft84afd992008-07-23 21:27:32 -0700224
Mel Gormana1e78772008-07-23 21:27:23 -0700225/*
226 * These helpers are used to track how many pages are reserved for
227 * faults in a MAP_PRIVATE mapping. Only the process that called mmap()
228 * is guaranteed to have their future faults succeed.
229 *
230 * With the exception of reset_vma_resv_huge_pages() which is called at fork(),
231 * the reserve counters are updated with the hugetlb_lock held. It is safe
232 * to reset the VMA at fork() time as it is not in use yet and there is no
233 * chance of the global counters getting corrupted as a result of the values.
Andy Whitcroft84afd992008-07-23 21:27:32 -0700234 *
235 * The private mapping reservation is represented in a subtly different
236 * manner to a shared mapping. A shared mapping has a region map associated
237 * with the underlying file, this region map represents the backing file
238 * pages which have ever had a reservation assigned which this persists even
239 * after the page is instantiated. A private mapping has a region map
240 * associated with the original mmap which is attached to all VMAs which
241 * reference it, this region map represents those offsets which have consumed
242 * reservation ie. where pages have been instantiated.
Mel Gormana1e78772008-07-23 21:27:23 -0700243 */
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700244static unsigned long get_vma_private_data(struct vm_area_struct *vma)
245{
246 return (unsigned long)vma->vm_private_data;
247}
248
249static void set_vma_private_data(struct vm_area_struct *vma,
250 unsigned long value)
251{
252 vma->vm_private_data = (void *)value;
253}
254
Andy Whitcroft84afd992008-07-23 21:27:32 -0700255struct resv_map {
256 struct kref refs;
257 struct list_head regions;
258};
259
260struct resv_map *resv_map_alloc(void)
261{
262 struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL);
263 if (!resv_map)
264 return NULL;
265
266 kref_init(&resv_map->refs);
267 INIT_LIST_HEAD(&resv_map->regions);
268
269 return resv_map;
270}
271
272void resv_map_release(struct kref *ref)
273{
274 struct resv_map *resv_map = container_of(ref, struct resv_map, refs);
275
276 /* Clear out any active regions before we release the map. */
277 region_truncate(&resv_map->regions, 0);
278 kfree(resv_map);
279}
280
281static struct resv_map *vma_resv_map(struct vm_area_struct *vma)
Mel Gormana1e78772008-07-23 21:27:23 -0700282{
283 VM_BUG_ON(!is_vm_hugetlb_page(vma));
284 if (!(vma->vm_flags & VM_SHARED))
Andy Whitcroft84afd992008-07-23 21:27:32 -0700285 return (struct resv_map *)(get_vma_private_data(vma) &
286 ~HPAGE_RESV_MASK);
Mel Gormana1e78772008-07-23 21:27:23 -0700287 return 0;
288}
289
Andy Whitcroft84afd992008-07-23 21:27:32 -0700290static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map)
Mel Gormana1e78772008-07-23 21:27:23 -0700291{
292 VM_BUG_ON(!is_vm_hugetlb_page(vma));
293 VM_BUG_ON(vma->vm_flags & VM_SHARED);
294
Andy Whitcroft84afd992008-07-23 21:27:32 -0700295 set_vma_private_data(vma, (get_vma_private_data(vma) &
296 HPAGE_RESV_MASK) | (unsigned long)map);
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700297}
298
299static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags)
300{
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700301 VM_BUG_ON(!is_vm_hugetlb_page(vma));
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700302 VM_BUG_ON(vma->vm_flags & VM_SHARED);
303
304 set_vma_private_data(vma, get_vma_private_data(vma) | flags);
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700305}
306
307static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag)
308{
309 VM_BUG_ON(!is_vm_hugetlb_page(vma));
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700310
311 return (get_vma_private_data(vma) & flag) != 0;
Mel Gormana1e78772008-07-23 21:27:23 -0700312}
313
314/* Decrement the reserved pages in the hugepage pool by one */
Andi Kleena5516432008-07-23 21:27:41 -0700315static void decrement_hugepage_resv_vma(struct hstate *h,
316 struct vm_area_struct *vma)
Mel Gormana1e78772008-07-23 21:27:23 -0700317{
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700318 if (vma->vm_flags & VM_NORESERVE)
319 return;
320
Mel Gormana1e78772008-07-23 21:27:23 -0700321 if (vma->vm_flags & VM_SHARED) {
322 /* Shared mappings always use reserves */
Andi Kleena5516432008-07-23 21:27:41 -0700323 h->resv_huge_pages--;
Andy Whitcroft84afd992008-07-23 21:27:32 -0700324 } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
Mel Gormana1e78772008-07-23 21:27:23 -0700325 /*
326 * Only the process that called mmap() has reserves for
327 * private mappings.
328 */
Andi Kleena5516432008-07-23 21:27:41 -0700329 h->resv_huge_pages--;
Mel Gormana1e78772008-07-23 21:27:23 -0700330 }
331}
332
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700333/* Reset counters to 0 and clear all HPAGE_RESV_* flags */
Mel Gormana1e78772008-07-23 21:27:23 -0700334void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
335{
336 VM_BUG_ON(!is_vm_hugetlb_page(vma));
337 if (!(vma->vm_flags & VM_SHARED))
338 vma->vm_private_data = (void *)0;
339}
340
341/* Returns true if the VMA has associated reserve pages */
342static int vma_has_private_reserves(struct vm_area_struct *vma)
343{
344 if (vma->vm_flags & VM_SHARED)
345 return 0;
Andy Whitcroft84afd992008-07-23 21:27:32 -0700346 if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER))
Mel Gormana1e78772008-07-23 21:27:23 -0700347 return 0;
348 return 1;
349}
350
Andi Kleena5516432008-07-23 21:27:41 -0700351static void clear_huge_page(struct page *page,
352 unsigned long addr, unsigned long sz)
David Gibson79ac6ba2006-03-22 00:08:51 -0800353{
354 int i;
355
356 might_sleep();
Andi Kleena5516432008-07-23 21:27:41 -0700357 for (i = 0; i < sz/PAGE_SIZE; i++) {
David Gibson79ac6ba2006-03-22 00:08:51 -0800358 cond_resched();
Ralf Baechle281e0e32007-10-01 01:20:10 -0700359 clear_user_highpage(page + i, addr + i * PAGE_SIZE);
David Gibson79ac6ba2006-03-22 00:08:51 -0800360 }
361}
362
363static void copy_huge_page(struct page *dst, struct page *src,
Atsushi Nemoto9de455b2006-12-12 17:14:55 +0000364 unsigned long addr, struct vm_area_struct *vma)
David Gibson79ac6ba2006-03-22 00:08:51 -0800365{
366 int i;
Andi Kleena5516432008-07-23 21:27:41 -0700367 struct hstate *h = hstate_vma(vma);
David Gibson79ac6ba2006-03-22 00:08:51 -0800368
369 might_sleep();
Andi Kleena5516432008-07-23 21:27:41 -0700370 for (i = 0; i < pages_per_huge_page(h); i++) {
David Gibson79ac6ba2006-03-22 00:08:51 -0800371 cond_resched();
Atsushi Nemoto9de455b2006-12-12 17:14:55 +0000372 copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma);
David Gibson79ac6ba2006-03-22 00:08:51 -0800373 }
374}
375
Andi Kleena5516432008-07-23 21:27:41 -0700376static void enqueue_huge_page(struct hstate *h, struct page *page)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377{
378 int nid = page_to_nid(page);
Andi Kleena5516432008-07-23 21:27:41 -0700379 list_add(&page->lru, &h->hugepage_freelists[nid]);
380 h->free_huge_pages++;
381 h->free_huge_pages_node[nid]++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382}
383
Andi Kleena5516432008-07-23 21:27:41 -0700384static struct page *dequeue_huge_page(struct hstate *h)
Nishanth Aravamudan348e1e02008-03-04 14:29:42 -0800385{
386 int nid;
387 struct page *page = NULL;
388
389 for (nid = 0; nid < MAX_NUMNODES; ++nid) {
Andi Kleena5516432008-07-23 21:27:41 -0700390 if (!list_empty(&h->hugepage_freelists[nid])) {
391 page = list_entry(h->hugepage_freelists[nid].next,
Nishanth Aravamudan348e1e02008-03-04 14:29:42 -0800392 struct page, lru);
393 list_del(&page->lru);
Andi Kleena5516432008-07-23 21:27:41 -0700394 h->free_huge_pages--;
395 h->free_huge_pages_node[nid]--;
Nishanth Aravamudan348e1e02008-03-04 14:29:42 -0800396 break;
397 }
398 }
399 return page;
400}
401
Andi Kleena5516432008-07-23 21:27:41 -0700402static struct page *dequeue_huge_page_vma(struct hstate *h,
403 struct vm_area_struct *vma,
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700404 unsigned long address, int avoid_reserve)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405{
Nishanth Aravamudan31a5c6e2007-07-15 23:38:02 -0700406 int nid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 struct page *page = NULL;
Lee Schermerhorn480eccf2007-09-18 22:46:47 -0700408 struct mempolicy *mpol;
Mel Gorman19770b32008-04-28 02:12:18 -0700409 nodemask_t *nodemask;
Mel Gorman396faf02007-07-17 04:03:13 -0700410 struct zonelist *zonelist = huge_zonelist(vma, address,
Mel Gorman19770b32008-04-28 02:12:18 -0700411 htlb_alloc_mask, &mpol, &nodemask);
Mel Gormandd1a2392008-04-28 02:12:17 -0700412 struct zone *zone;
413 struct zoneref *z;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414
Mel Gormana1e78772008-07-23 21:27:23 -0700415 /*
416 * A child process with MAP_PRIVATE mappings created by their parent
417 * have no page reserves. This check ensures that reservations are
418 * not "stolen". The child may still get SIGKILLed
419 */
420 if (!vma_has_private_reserves(vma) &&
Andi Kleena5516432008-07-23 21:27:41 -0700421 h->free_huge_pages - h->resv_huge_pages == 0)
Mel Gormana1e78772008-07-23 21:27:23 -0700422 return NULL;
423
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700424 /* If reserves cannot be used, ensure enough pages are in the pool */
Andi Kleena5516432008-07-23 21:27:41 -0700425 if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0)
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700426 return NULL;
427
Mel Gorman19770b32008-04-28 02:12:18 -0700428 for_each_zone_zonelist_nodemask(zone, z, zonelist,
429 MAX_NR_ZONES - 1, nodemask) {
Mel Gorman54a6eb52008-04-28 02:12:16 -0700430 nid = zone_to_nid(zone);
431 if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) &&
Andi Kleena5516432008-07-23 21:27:41 -0700432 !list_empty(&h->hugepage_freelists[nid])) {
433 page = list_entry(h->hugepage_freelists[nid].next,
Andrew Morton3abf7af2007-07-19 01:49:08 -0700434 struct page, lru);
435 list_del(&page->lru);
Andi Kleena5516432008-07-23 21:27:41 -0700436 h->free_huge_pages--;
437 h->free_huge_pages_node[nid]--;
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700438
439 if (!avoid_reserve)
Andi Kleena5516432008-07-23 21:27:41 -0700440 decrement_hugepage_resv_vma(h, vma);
Mel Gormana1e78772008-07-23 21:27:23 -0700441
Ken Chen5ab3ee72007-07-23 18:44:00 -0700442 break;
Andrew Morton3abf7af2007-07-19 01:49:08 -0700443 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 }
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700445 mpol_cond_put(mpol);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 return page;
447}
448
Andi Kleena5516432008-07-23 21:27:41 -0700449static void update_and_free_page(struct hstate *h, struct page *page)
Adam Litke6af2acb2007-10-16 01:26:16 -0700450{
451 int i;
Andi Kleena5516432008-07-23 21:27:41 -0700452
453 h->nr_huge_pages--;
454 h->nr_huge_pages_node[page_to_nid(page)]--;
455 for (i = 0; i < pages_per_huge_page(h); i++) {
Adam Litke6af2acb2007-10-16 01:26:16 -0700456 page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced |
457 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved |
458 1 << PG_private | 1<< PG_writeback);
459 }
460 set_compound_page_dtor(page, NULL);
461 set_page_refcounted(page);
Gerald Schaefer7f2e9522008-04-28 02:13:29 -0700462 arch_release_hugepage(page);
Andi Kleena5516432008-07-23 21:27:41 -0700463 __free_pages(page, huge_page_order(h));
Adam Litke6af2acb2007-10-16 01:26:16 -0700464}
465
Andi Kleene5ff2152008-07-23 21:27:42 -0700466struct hstate *size_to_hstate(unsigned long size)
467{
468 struct hstate *h;
469
470 for_each_hstate(h) {
471 if (huge_page_size(h) == size)
472 return h;
473 }
474 return NULL;
475}
476
David Gibson27a85ef2006-03-22 00:08:56 -0800477static void free_huge_page(struct page *page)
478{
Andi Kleena5516432008-07-23 21:27:41 -0700479 /*
480 * Can't pass hstate in here because it is called from the
481 * compound page destructor.
482 */
Andi Kleene5ff2152008-07-23 21:27:42 -0700483 struct hstate *h = page_hstate(page);
Adam Litke7893d1d2007-10-16 01:26:18 -0700484 int nid = page_to_nid(page);
Adam Litkec79fb752007-11-14 16:59:38 -0800485 struct address_space *mapping;
David Gibson27a85ef2006-03-22 00:08:56 -0800486
Adam Litkec79fb752007-11-14 16:59:38 -0800487 mapping = (struct address_space *) page_private(page);
Andy Whitcrofte5df70a2008-02-23 15:23:32 -0800488 set_page_private(page, 0);
Adam Litke7893d1d2007-10-16 01:26:18 -0700489 BUG_ON(page_count(page));
David Gibson27a85ef2006-03-22 00:08:56 -0800490 INIT_LIST_HEAD(&page->lru);
491
492 spin_lock(&hugetlb_lock);
Andi Kleenaa888a72008-07-23 21:27:47 -0700493 if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) {
Andi Kleena5516432008-07-23 21:27:41 -0700494 update_and_free_page(h, page);
495 h->surplus_huge_pages--;
496 h->surplus_huge_pages_node[nid]--;
Adam Litke7893d1d2007-10-16 01:26:18 -0700497 } else {
Andi Kleena5516432008-07-23 21:27:41 -0700498 enqueue_huge_page(h, page);
Adam Litke7893d1d2007-10-16 01:26:18 -0700499 }
David Gibson27a85ef2006-03-22 00:08:56 -0800500 spin_unlock(&hugetlb_lock);
Adam Litkec79fb752007-11-14 16:59:38 -0800501 if (mapping)
Adam Litke9a119c02007-11-14 16:59:41 -0800502 hugetlb_put_quota(mapping, 1);
David Gibson27a85ef2006-03-22 00:08:56 -0800503}
504
Adam Litke7893d1d2007-10-16 01:26:18 -0700505/*
506 * Increment or decrement surplus_huge_pages. Keep node-specific counters
507 * balanced by operating on them in a round-robin fashion.
508 * Returns 1 if an adjustment was made.
509 */
Andi Kleena5516432008-07-23 21:27:41 -0700510static int adjust_pool_surplus(struct hstate *h, int delta)
Adam Litke7893d1d2007-10-16 01:26:18 -0700511{
512 static int prev_nid;
513 int nid = prev_nid;
514 int ret = 0;
515
516 VM_BUG_ON(delta != -1 && delta != 1);
517 do {
518 nid = next_node(nid, node_online_map);
519 if (nid == MAX_NUMNODES)
520 nid = first_node(node_online_map);
521
522 /* To shrink on this node, there must be a surplus page */
Andi Kleena5516432008-07-23 21:27:41 -0700523 if (delta < 0 && !h->surplus_huge_pages_node[nid])
Adam Litke7893d1d2007-10-16 01:26:18 -0700524 continue;
525 /* Surplus cannot exceed the total number of pages */
Andi Kleena5516432008-07-23 21:27:41 -0700526 if (delta > 0 && h->surplus_huge_pages_node[nid] >=
527 h->nr_huge_pages_node[nid])
Adam Litke7893d1d2007-10-16 01:26:18 -0700528 continue;
529
Andi Kleena5516432008-07-23 21:27:41 -0700530 h->surplus_huge_pages += delta;
531 h->surplus_huge_pages_node[nid] += delta;
Adam Litke7893d1d2007-10-16 01:26:18 -0700532 ret = 1;
533 break;
534 } while (nid != prev_nid);
535
536 prev_nid = nid;
537 return ret;
538}
539
Andi Kleena5516432008-07-23 21:27:41 -0700540static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
Andi Kleenb7ba30c2008-07-23 21:27:40 -0700541{
542 set_compound_page_dtor(page, free_huge_page);
543 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -0700544 h->nr_huge_pages++;
545 h->nr_huge_pages_node[nid]++;
Andi Kleenb7ba30c2008-07-23 21:27:40 -0700546 spin_unlock(&hugetlb_lock);
547 put_page(page); /* free it into the hugepage allocator */
548}
549
Andi Kleena5516432008-07-23 21:27:41 -0700550static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 struct page *page;
Joe Jinf96efd52007-07-15 23:38:12 -0700553
Andi Kleenaa888a72008-07-23 21:27:47 -0700554 if (h->order >= MAX_ORDER)
555 return NULL;
556
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700557 page = alloc_pages_node(nid,
Nishanth Aravamudan551883a2008-04-29 00:58:26 -0700558 htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
559 __GFP_REPEAT|__GFP_NOWARN,
Andi Kleena5516432008-07-23 21:27:41 -0700560 huge_page_order(h));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 if (page) {
Gerald Schaefer7f2e9522008-04-28 02:13:29 -0700562 if (arch_prepare_hugepage(page)) {
563 __free_pages(page, HUGETLB_PAGE_ORDER);
Harvey Harrison7b8ee842008-04-28 14:13:19 -0700564 return NULL;
Gerald Schaefer7f2e9522008-04-28 02:13:29 -0700565 }
Andi Kleena5516432008-07-23 21:27:41 -0700566 prep_new_huge_page(h, page, nid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 }
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700568
569 return page;
570}
571
Andi Kleen5ced66c2008-07-23 21:27:45 -0700572/*
573 * Use a helper variable to find the next node and then
574 * copy it back to hugetlb_next_nid afterwards:
575 * otherwise there's a window in which a racer might
576 * pass invalid nid MAX_NUMNODES to alloc_pages_node.
577 * But we don't need to use a spin_lock here: it really
578 * doesn't matter if occasionally a racer chooses the
579 * same nid as we do. Move nid forward in the mask even
580 * if we just successfully allocated a hugepage so that
581 * the next caller gets hugepages on the next node.
582 */
583static int hstate_next_node(struct hstate *h)
584{
585 int next_nid;
586 next_nid = next_node(h->hugetlb_next_nid, node_online_map);
587 if (next_nid == MAX_NUMNODES)
588 next_nid = first_node(node_online_map);
589 h->hugetlb_next_nid = next_nid;
590 return next_nid;
591}
592
Andi Kleena5516432008-07-23 21:27:41 -0700593static int alloc_fresh_huge_page(struct hstate *h)
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700594{
595 struct page *page;
596 int start_nid;
597 int next_nid;
598 int ret = 0;
599
Andi Kleena5516432008-07-23 21:27:41 -0700600 start_nid = h->hugetlb_next_nid;
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700601
602 do {
Andi Kleena5516432008-07-23 21:27:41 -0700603 page = alloc_fresh_huge_page_node(h, h->hugetlb_next_nid);
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700604 if (page)
605 ret = 1;
Andi Kleen5ced66c2008-07-23 21:27:45 -0700606 next_nid = hstate_next_node(h);
Andi Kleena5516432008-07-23 21:27:41 -0700607 } while (!page && h->hugetlb_next_nid != start_nid);
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700608
Adam Litke3b116302008-04-28 02:13:06 -0700609 if (ret)
610 count_vm_event(HTLB_BUDDY_PGALLOC);
611 else
612 count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
613
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700614 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615}
616
Andi Kleena5516432008-07-23 21:27:41 -0700617static struct page *alloc_buddy_huge_page(struct hstate *h,
618 struct vm_area_struct *vma, unsigned long address)
Adam Litke7893d1d2007-10-16 01:26:18 -0700619{
620 struct page *page;
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800621 unsigned int nid;
Adam Litke7893d1d2007-10-16 01:26:18 -0700622
Andi Kleenaa888a72008-07-23 21:27:47 -0700623 if (h->order >= MAX_ORDER)
624 return NULL;
625
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800626 /*
627 * Assume we will successfully allocate the surplus page to
628 * prevent racing processes from causing the surplus to exceed
629 * overcommit
630 *
631 * This however introduces a different race, where a process B
632 * tries to grow the static hugepage pool while alloc_pages() is
633 * called by process A. B will only examine the per-node
634 * counters in determining if surplus huge pages can be
635 * converted to normal huge pages in adjust_pool_surplus(). A
636 * won't be able to increment the per-node counter, until the
637 * lock is dropped by B, but B doesn't drop hugetlb_lock until
638 * no more huge pages can be converted from surplus to normal
639 * state (and doesn't try to convert again). Thus, we have a
640 * case where a surplus huge page exists, the pool is grown, and
641 * the surplus huge page still exists after, even though it
642 * should just have been converted to a normal huge page. This
643 * does not leak memory, though, as the hugepage will be freed
644 * once it is out of use. It also does not allow the counters to
645 * go out of whack in adjust_pool_surplus() as we don't modify
646 * the node values until we've gotten the hugepage and only the
647 * per-node value is checked there.
648 */
649 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -0700650 if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) {
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800651 spin_unlock(&hugetlb_lock);
652 return NULL;
653 } else {
Andi Kleena5516432008-07-23 21:27:41 -0700654 h->nr_huge_pages++;
655 h->surplus_huge_pages++;
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800656 }
657 spin_unlock(&hugetlb_lock);
658
Nishanth Aravamudan551883a2008-04-29 00:58:26 -0700659 page = alloc_pages(htlb_alloc_mask|__GFP_COMP|
660 __GFP_REPEAT|__GFP_NOWARN,
Andi Kleena5516432008-07-23 21:27:41 -0700661 huge_page_order(h));
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800662
663 spin_lock(&hugetlb_lock);
Adam Litke7893d1d2007-10-16 01:26:18 -0700664 if (page) {
Adam Litke2668db92008-03-10 11:43:50 -0700665 /*
666 * This page is now managed by the hugetlb allocator and has
667 * no users -- drop the buddy allocator's reference.
668 */
669 put_page_testzero(page);
670 VM_BUG_ON(page_count(page));
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800671 nid = page_to_nid(page);
Adam Litke7893d1d2007-10-16 01:26:18 -0700672 set_compound_page_dtor(page, free_huge_page);
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800673 /*
674 * We incremented the global counters already
675 */
Andi Kleena5516432008-07-23 21:27:41 -0700676 h->nr_huge_pages_node[nid]++;
677 h->surplus_huge_pages_node[nid]++;
Adam Litke3b116302008-04-28 02:13:06 -0700678 __count_vm_event(HTLB_BUDDY_PGALLOC);
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800679 } else {
Andi Kleena5516432008-07-23 21:27:41 -0700680 h->nr_huge_pages--;
681 h->surplus_huge_pages--;
Adam Litke3b116302008-04-28 02:13:06 -0700682 __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
Adam Litke7893d1d2007-10-16 01:26:18 -0700683 }
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800684 spin_unlock(&hugetlb_lock);
Adam Litke7893d1d2007-10-16 01:26:18 -0700685
686 return page;
687}
688
Adam Litkee4e574b2007-10-16 01:26:19 -0700689/*
690 * Increase the hugetlb pool such that it can accomodate a reservation
691 * of size 'delta'.
692 */
Andi Kleena5516432008-07-23 21:27:41 -0700693static int gather_surplus_pages(struct hstate *h, int delta)
Adam Litkee4e574b2007-10-16 01:26:19 -0700694{
695 struct list_head surplus_list;
696 struct page *page, *tmp;
697 int ret, i;
698 int needed, allocated;
699
Andi Kleena5516432008-07-23 21:27:41 -0700700 needed = (h->resv_huge_pages + delta) - h->free_huge_pages;
Adam Litkeac09b3a2008-03-04 14:29:38 -0800701 if (needed <= 0) {
Andi Kleena5516432008-07-23 21:27:41 -0700702 h->resv_huge_pages += delta;
Adam Litkee4e574b2007-10-16 01:26:19 -0700703 return 0;
Adam Litkeac09b3a2008-03-04 14:29:38 -0800704 }
Adam Litkee4e574b2007-10-16 01:26:19 -0700705
706 allocated = 0;
707 INIT_LIST_HEAD(&surplus_list);
708
709 ret = -ENOMEM;
710retry:
711 spin_unlock(&hugetlb_lock);
712 for (i = 0; i < needed; i++) {
Andi Kleena5516432008-07-23 21:27:41 -0700713 page = alloc_buddy_huge_page(h, NULL, 0);
Adam Litkee4e574b2007-10-16 01:26:19 -0700714 if (!page) {
715 /*
716 * We were not able to allocate enough pages to
717 * satisfy the entire reservation so we free what
718 * we've allocated so far.
719 */
720 spin_lock(&hugetlb_lock);
721 needed = 0;
722 goto free;
723 }
724
725 list_add(&page->lru, &surplus_list);
726 }
727 allocated += needed;
728
729 /*
730 * After retaking hugetlb_lock, we need to recalculate 'needed'
731 * because either resv_huge_pages or free_huge_pages may have changed.
732 */
733 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -0700734 needed = (h->resv_huge_pages + delta) -
735 (h->free_huge_pages + allocated);
Adam Litkee4e574b2007-10-16 01:26:19 -0700736 if (needed > 0)
737 goto retry;
738
739 /*
740 * The surplus_list now contains _at_least_ the number of extra pages
741 * needed to accomodate the reservation. Add the appropriate number
742 * of pages to the hugetlb pool and free the extras back to the buddy
Adam Litkeac09b3a2008-03-04 14:29:38 -0800743 * allocator. Commit the entire reservation here to prevent another
744 * process from stealing the pages as they are added to the pool but
745 * before they are reserved.
Adam Litkee4e574b2007-10-16 01:26:19 -0700746 */
747 needed += allocated;
Andi Kleena5516432008-07-23 21:27:41 -0700748 h->resv_huge_pages += delta;
Adam Litkee4e574b2007-10-16 01:26:19 -0700749 ret = 0;
750free:
Adam Litke19fc3f02008-04-28 02:12:20 -0700751 /* Free the needed pages to the hugetlb pool */
Adam Litkee4e574b2007-10-16 01:26:19 -0700752 list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
Adam Litke19fc3f02008-04-28 02:12:20 -0700753 if ((--needed) < 0)
754 break;
Adam Litkee4e574b2007-10-16 01:26:19 -0700755 list_del(&page->lru);
Andi Kleena5516432008-07-23 21:27:41 -0700756 enqueue_huge_page(h, page);
Adam Litke19fc3f02008-04-28 02:12:20 -0700757 }
758
759 /* Free unnecessary surplus pages to the buddy allocator */
760 if (!list_empty(&surplus_list)) {
761 spin_unlock(&hugetlb_lock);
762 list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
763 list_del(&page->lru);
Adam Litkeaf767cb2007-10-16 01:26:25 -0700764 /*
Adam Litke2668db92008-03-10 11:43:50 -0700765 * The page has a reference count of zero already, so
766 * call free_huge_page directly instead of using
767 * put_page. This must be done with hugetlb_lock
Adam Litkeaf767cb2007-10-16 01:26:25 -0700768 * unlocked which is safe because free_huge_page takes
769 * hugetlb_lock before deciding how to free the page.
770 */
Adam Litke2668db92008-03-10 11:43:50 -0700771 free_huge_page(page);
Adam Litkeaf767cb2007-10-16 01:26:25 -0700772 }
Adam Litke19fc3f02008-04-28 02:12:20 -0700773 spin_lock(&hugetlb_lock);
Adam Litkee4e574b2007-10-16 01:26:19 -0700774 }
775
776 return ret;
777}
778
779/*
780 * When releasing a hugetlb pool reservation, any surplus pages that were
781 * allocated to satisfy the reservation must be explicitly freed if they were
782 * never used.
783 */
Andi Kleena5516432008-07-23 21:27:41 -0700784static void return_unused_surplus_pages(struct hstate *h,
785 unsigned long unused_resv_pages)
Adam Litkee4e574b2007-10-16 01:26:19 -0700786{
787 static int nid = -1;
788 struct page *page;
789 unsigned long nr_pages;
790
Nishanth Aravamudan11320d12008-03-26 14:40:20 -0700791 /*
792 * We want to release as many surplus pages as possible, spread
793 * evenly across all nodes. Iterate across all nodes until we
794 * can no longer free unreserved surplus pages. This occurs when
795 * the nodes with surplus pages have no free pages.
796 */
797 unsigned long remaining_iterations = num_online_nodes();
798
Adam Litkeac09b3a2008-03-04 14:29:38 -0800799 /* Uncommit the reservation */
Andi Kleena5516432008-07-23 21:27:41 -0700800 h->resv_huge_pages -= unused_resv_pages;
Adam Litkeac09b3a2008-03-04 14:29:38 -0800801
Andi Kleenaa888a72008-07-23 21:27:47 -0700802 /* Cannot return gigantic pages currently */
803 if (h->order >= MAX_ORDER)
804 return;
805
Andi Kleena5516432008-07-23 21:27:41 -0700806 nr_pages = min(unused_resv_pages, h->surplus_huge_pages);
Adam Litkee4e574b2007-10-16 01:26:19 -0700807
Nishanth Aravamudan11320d12008-03-26 14:40:20 -0700808 while (remaining_iterations-- && nr_pages) {
Adam Litkee4e574b2007-10-16 01:26:19 -0700809 nid = next_node(nid, node_online_map);
810 if (nid == MAX_NUMNODES)
811 nid = first_node(node_online_map);
812
Andi Kleena5516432008-07-23 21:27:41 -0700813 if (!h->surplus_huge_pages_node[nid])
Adam Litkee4e574b2007-10-16 01:26:19 -0700814 continue;
815
Andi Kleena5516432008-07-23 21:27:41 -0700816 if (!list_empty(&h->hugepage_freelists[nid])) {
817 page = list_entry(h->hugepage_freelists[nid].next,
Adam Litkee4e574b2007-10-16 01:26:19 -0700818 struct page, lru);
819 list_del(&page->lru);
Andi Kleena5516432008-07-23 21:27:41 -0700820 update_and_free_page(h, page);
821 h->free_huge_pages--;
822 h->free_huge_pages_node[nid]--;
823 h->surplus_huge_pages--;
824 h->surplus_huge_pages_node[nid]--;
Adam Litkee4e574b2007-10-16 01:26:19 -0700825 nr_pages--;
Nishanth Aravamudan11320d12008-03-26 14:40:20 -0700826 remaining_iterations = num_online_nodes();
Adam Litkee4e574b2007-10-16 01:26:19 -0700827 }
828 }
829}
830
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700831/*
832 * Determine if the huge page at addr within the vma has an associated
833 * reservation. Where it does not we will need to logically increase
834 * reservation and actually increase quota before an allocation can occur.
835 * Where any new reservation would be required the reservation change is
836 * prepared, but not committed. Once the page has been quota'd allocated
837 * an instantiated the change should be committed via vma_commit_reservation.
838 * No action is required on failure.
839 */
Andi Kleena5516432008-07-23 21:27:41 -0700840static int vma_needs_reservation(struct hstate *h,
841 struct vm_area_struct *vma, unsigned long addr)
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700842{
843 struct address_space *mapping = vma->vm_file->f_mapping;
844 struct inode *inode = mapping->host;
845
846 if (vma->vm_flags & VM_SHARED) {
Andi Kleena5516432008-07-23 21:27:41 -0700847 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700848 return region_chg(&inode->i_mapping->private_list,
849 idx, idx + 1);
850
Andy Whitcroft84afd992008-07-23 21:27:32 -0700851 } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
852 return 1;
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700853
Andy Whitcroft84afd992008-07-23 21:27:32 -0700854 } else {
855 int err;
Andi Kleena5516432008-07-23 21:27:41 -0700856 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
Andy Whitcroft84afd992008-07-23 21:27:32 -0700857 struct resv_map *reservations = vma_resv_map(vma);
858
859 err = region_chg(&reservations->regions, idx, idx + 1);
860 if (err < 0)
861 return err;
862 return 0;
863 }
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700864}
Andi Kleena5516432008-07-23 21:27:41 -0700865static void vma_commit_reservation(struct hstate *h,
866 struct vm_area_struct *vma, unsigned long addr)
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700867{
868 struct address_space *mapping = vma->vm_file->f_mapping;
869 struct inode *inode = mapping->host;
870
871 if (vma->vm_flags & VM_SHARED) {
Andi Kleena5516432008-07-23 21:27:41 -0700872 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700873 region_add(&inode->i_mapping->private_list, idx, idx + 1);
Andy Whitcroft84afd992008-07-23 21:27:32 -0700874
875 } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
Andi Kleena5516432008-07-23 21:27:41 -0700876 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
Andy Whitcroft84afd992008-07-23 21:27:32 -0700877 struct resv_map *reservations = vma_resv_map(vma);
878
879 /* Mark this page used in the map. */
880 region_add(&reservations->regions, idx, idx + 1);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700881 }
882}
883
David Gibson27a85ef2006-03-22 00:08:56 -0800884static struct page *alloc_huge_page(struct vm_area_struct *vma,
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700885 unsigned long addr, int avoid_reserve)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886{
Andi Kleena5516432008-07-23 21:27:41 -0700887 struct hstate *h = hstate_vma(vma);
Adam Litke348ea202007-11-14 16:59:37 -0800888 struct page *page;
Adam Litke2fc39ce2007-11-14 16:59:39 -0800889 struct address_space *mapping = vma->vm_file->f_mapping;
Mel Gormana1e78772008-07-23 21:27:23 -0700890 struct inode *inode = mapping->host;
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700891 unsigned int chg;
Adam Litke2fc39ce2007-11-14 16:59:39 -0800892
Mel Gormana1e78772008-07-23 21:27:23 -0700893 /*
894 * Processes that did not create the mapping will have no reserves and
895 * will not have accounted against quota. Check that the quota can be
896 * made before satisfying the allocation
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700897 * MAP_NORESERVE mappings may also need pages and quota allocated
898 * if no reserve mapping overlaps.
Mel Gormana1e78772008-07-23 21:27:23 -0700899 */
Andi Kleena5516432008-07-23 21:27:41 -0700900 chg = vma_needs_reservation(h, vma, addr);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700901 if (chg < 0)
902 return ERR_PTR(chg);
903 if (chg)
Mel Gormana1e78772008-07-23 21:27:23 -0700904 if (hugetlb_get_quota(inode->i_mapping, chg))
905 return ERR_PTR(-ENOSPC);
Mel Gormana1e78772008-07-23 21:27:23 -0700906
907 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -0700908 page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve);
Mel Gormana1e78772008-07-23 21:27:23 -0700909 spin_unlock(&hugetlb_lock);
910
911 if (!page) {
Andi Kleena5516432008-07-23 21:27:41 -0700912 page = alloc_buddy_huge_page(h, vma, addr);
Mel Gormana1e78772008-07-23 21:27:23 -0700913 if (!page) {
914 hugetlb_put_quota(inode->i_mapping, chg);
915 return ERR_PTR(-VM_FAULT_OOM);
916 }
917 }
918
919 set_page_refcounted(page);
920 set_page_private(page, (unsigned long) mapping);
921
Andi Kleena5516432008-07-23 21:27:41 -0700922 vma_commit_reservation(h, vma, addr);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700923
Adam Litke90d8b7e2007-11-14 16:59:42 -0800924 return page;
David Gibsonb45b5bd2006-03-22 00:08:55 -0800925}
926
Andi Kleenaa888a72008-07-23 21:27:47 -0700927static __initdata LIST_HEAD(huge_boot_pages);
928
929struct huge_bootmem_page {
930 struct list_head list;
931 struct hstate *hstate;
932};
933
934static int __init alloc_bootmem_huge_page(struct hstate *h)
935{
936 struct huge_bootmem_page *m;
937 int nr_nodes = nodes_weight(node_online_map);
938
939 while (nr_nodes) {
940 void *addr;
941
942 addr = __alloc_bootmem_node_nopanic(
943 NODE_DATA(h->hugetlb_next_nid),
944 huge_page_size(h), huge_page_size(h), 0);
945
946 if (addr) {
947 /*
948 * Use the beginning of the huge page to store the
949 * huge_bootmem_page struct (until gather_bootmem
950 * puts them into the mem_map).
951 */
952 m = addr;
953 if (m)
954 goto found;
955 }
956 hstate_next_node(h);
957 nr_nodes--;
958 }
959 return 0;
960
961found:
962 BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1));
963 /* Put them into a private list first because mem_map is not up yet */
964 list_add(&m->list, &huge_boot_pages);
965 m->hstate = h;
966 return 1;
967}
968
969/* Put bootmem huge pages into the standard lists after mem_map is up */
970static void __init gather_bootmem_prealloc(void)
971{
972 struct huge_bootmem_page *m;
973
974 list_for_each_entry(m, &huge_boot_pages, list) {
975 struct page *page = virt_to_page(m);
976 struct hstate *h = m->hstate;
977 __ClearPageReserved(page);
978 WARN_ON(page_count(page) != 1);
979 prep_compound_page(page, h->order);
980 prep_new_huge_page(h, page, page_to_nid(page));
981 }
982}
983
Andi Kleen8faa8b02008-07-23 21:27:48 -0700984static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985{
986 unsigned long i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987
Andi Kleene5ff2152008-07-23 21:27:42 -0700988 for (i = 0; i < h->max_huge_pages; ++i) {
Andi Kleenaa888a72008-07-23 21:27:47 -0700989 if (h->order >= MAX_ORDER) {
990 if (!alloc_bootmem_huge_page(h))
991 break;
992 } else if (!alloc_fresh_huge_page(h))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 }
Andi Kleen8faa8b02008-07-23 21:27:48 -0700995 h->max_huge_pages = i;
Andi Kleene5ff2152008-07-23 21:27:42 -0700996}
997
998static void __init hugetlb_init_hstates(void)
999{
1000 struct hstate *h;
1001
1002 for_each_hstate(h) {
Andi Kleen8faa8b02008-07-23 21:27:48 -07001003 /* oversize hugepages were init'ed in early boot */
1004 if (h->order < MAX_ORDER)
1005 hugetlb_hstate_alloc_pages(h);
Andi Kleene5ff2152008-07-23 21:27:42 -07001006 }
1007}
1008
Andi Kleen4abd32d2008-07-23 21:27:49 -07001009static char * __init memfmt(char *buf, unsigned long n)
1010{
1011 if (n >= (1UL << 30))
1012 sprintf(buf, "%lu GB", n >> 30);
1013 else if (n >= (1UL << 20))
1014 sprintf(buf, "%lu MB", n >> 20);
1015 else
1016 sprintf(buf, "%lu KB", n >> 10);
1017 return buf;
1018}
1019
Andi Kleene5ff2152008-07-23 21:27:42 -07001020static void __init report_hugepages(void)
1021{
1022 struct hstate *h;
1023
1024 for_each_hstate(h) {
Andi Kleen4abd32d2008-07-23 21:27:49 -07001025 char buf[32];
1026 printk(KERN_INFO "HugeTLB registered %s page size, "
1027 "pre-allocated %ld pages\n",
1028 memfmt(buf, huge_page_size(h)),
1029 h->free_huge_pages);
Andi Kleene5ff2152008-07-23 21:27:42 -07001030 }
1031}
1032
Linus Torvalds1da177e2005-04-16 15:20:36 -07001033#ifdef CONFIG_SYSCTL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034#ifdef CONFIG_HIGHMEM
Andi Kleena5516432008-07-23 21:27:41 -07001035static void try_to_free_low(struct hstate *h, unsigned long count)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036{
Christoph Lameter4415cc82006-09-25 23:31:55 -07001037 int i;
1038
Andi Kleenaa888a72008-07-23 21:27:47 -07001039 if (h->order >= MAX_ORDER)
1040 return;
1041
Linus Torvalds1da177e2005-04-16 15:20:36 -07001042 for (i = 0; i < MAX_NUMNODES; ++i) {
1043 struct page *page, *next;
Andi Kleena5516432008-07-23 21:27:41 -07001044 struct list_head *freel = &h->hugepage_freelists[i];
1045 list_for_each_entry_safe(page, next, freel, lru) {
1046 if (count >= h->nr_huge_pages)
Adam Litke6b0c8802007-10-16 01:26:23 -07001047 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001048 if (PageHighMem(page))
1049 continue;
1050 list_del(&page->lru);
Andi Kleene5ff2152008-07-23 21:27:42 -07001051 update_and_free_page(h, page);
Andi Kleena5516432008-07-23 21:27:41 -07001052 h->free_huge_pages--;
1053 h->free_huge_pages_node[page_to_nid(page)]--;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054 }
1055 }
1056}
1057#else
Andi Kleena5516432008-07-23 21:27:41 -07001058static inline void try_to_free_low(struct hstate *h, unsigned long count)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059{
1060}
1061#endif
1062
Andi Kleena5516432008-07-23 21:27:41 -07001063#define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)
Andi Kleene5ff2152008-07-23 21:27:42 -07001064static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001065{
Adam Litke7893d1d2007-10-16 01:26:18 -07001066 unsigned long min_count, ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067
Andi Kleenaa888a72008-07-23 21:27:47 -07001068 if (h->order >= MAX_ORDER)
1069 return h->max_huge_pages;
1070
Adam Litke7893d1d2007-10-16 01:26:18 -07001071 /*
1072 * Increase the pool size
1073 * First take pages out of surplus state. Then make up the
1074 * remaining difference by allocating fresh huge pages.
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -08001075 *
1076 * We might race with alloc_buddy_huge_page() here and be unable
1077 * to convert a surplus huge page to a normal huge page. That is
1078 * not critical, though, it just means the overall size of the
1079 * pool might be one hugepage larger than it needs to be, but
1080 * within all the constraints specified by the sysctls.
Adam Litke7893d1d2007-10-16 01:26:18 -07001081 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001082 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -07001083 while (h->surplus_huge_pages && count > persistent_huge_pages(h)) {
1084 if (!adjust_pool_surplus(h, -1))
Adam Litke7893d1d2007-10-16 01:26:18 -07001085 break;
1086 }
1087
Andi Kleena5516432008-07-23 21:27:41 -07001088 while (count > persistent_huge_pages(h)) {
Adam Litke7893d1d2007-10-16 01:26:18 -07001089 /*
1090 * If this allocation races such that we no longer need the
1091 * page, free_huge_page will handle it by freeing the page
1092 * and reducing the surplus.
1093 */
1094 spin_unlock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -07001095 ret = alloc_fresh_huge_page(h);
Adam Litke7893d1d2007-10-16 01:26:18 -07001096 spin_lock(&hugetlb_lock);
1097 if (!ret)
1098 goto out;
1099
1100 }
Adam Litke7893d1d2007-10-16 01:26:18 -07001101
1102 /*
1103 * Decrease the pool size
1104 * First return free pages to the buddy allocator (being careful
1105 * to keep enough around to satisfy reservations). Then place
1106 * pages into surplus state as needed so the pool will shrink
1107 * to the desired size as pages become free.
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -08001108 *
1109 * By placing pages into the surplus state independent of the
1110 * overcommit value, we are allowing the surplus pool size to
1111 * exceed overcommit. There are few sane options here. Since
1112 * alloc_buddy_huge_page() is checking the global counter,
1113 * though, we'll note that we're not allowed to exceed surplus
1114 * and won't grow the pool anywhere else. Not until one of the
1115 * sysctls are changed, or the surplus pages go out of use.
Adam Litke7893d1d2007-10-16 01:26:18 -07001116 */
Andi Kleena5516432008-07-23 21:27:41 -07001117 min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages;
Adam Litke6b0c8802007-10-16 01:26:23 -07001118 min_count = max(count, min_count);
Andi Kleena5516432008-07-23 21:27:41 -07001119 try_to_free_low(h, min_count);
1120 while (min_count < persistent_huge_pages(h)) {
1121 struct page *page = dequeue_huge_page(h);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 if (!page)
1123 break;
Andi Kleena5516432008-07-23 21:27:41 -07001124 update_and_free_page(h, page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001125 }
Andi Kleena5516432008-07-23 21:27:41 -07001126 while (count < persistent_huge_pages(h)) {
1127 if (!adjust_pool_surplus(h, 1))
Adam Litke7893d1d2007-10-16 01:26:18 -07001128 break;
1129 }
1130out:
Andi Kleena5516432008-07-23 21:27:41 -07001131 ret = persistent_huge_pages(h);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001132 spin_unlock(&hugetlb_lock);
Adam Litke7893d1d2007-10-16 01:26:18 -07001133 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134}
1135
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001136#define HSTATE_ATTR_RO(_name) \
1137 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
1138
1139#define HSTATE_ATTR(_name) \
1140 static struct kobj_attribute _name##_attr = \
1141 __ATTR(_name, 0644, _name##_show, _name##_store)
1142
1143static struct kobject *hugepages_kobj;
1144static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];
1145
1146static struct hstate *kobj_to_hstate(struct kobject *kobj)
1147{
1148 int i;
1149 for (i = 0; i < HUGE_MAX_HSTATE; i++)
1150 if (hstate_kobjs[i] == kobj)
1151 return &hstates[i];
1152 BUG();
1153 return NULL;
1154}
1155
1156static ssize_t nr_hugepages_show(struct kobject *kobj,
1157 struct kobj_attribute *attr, char *buf)
1158{
1159 struct hstate *h = kobj_to_hstate(kobj);
1160 return sprintf(buf, "%lu\n", h->nr_huge_pages);
1161}
1162static ssize_t nr_hugepages_store(struct kobject *kobj,
1163 struct kobj_attribute *attr, const char *buf, size_t count)
1164{
1165 int err;
1166 unsigned long input;
1167 struct hstate *h = kobj_to_hstate(kobj);
1168
1169 err = strict_strtoul(buf, 10, &input);
1170 if (err)
1171 return 0;
1172
1173 h->max_huge_pages = set_max_huge_pages(h, input);
1174
1175 return count;
1176}
1177HSTATE_ATTR(nr_hugepages);
1178
1179static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj,
1180 struct kobj_attribute *attr, char *buf)
1181{
1182 struct hstate *h = kobj_to_hstate(kobj);
1183 return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages);
1184}
1185static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj,
1186 struct kobj_attribute *attr, const char *buf, size_t count)
1187{
1188 int err;
1189 unsigned long input;
1190 struct hstate *h = kobj_to_hstate(kobj);
1191
1192 err = strict_strtoul(buf, 10, &input);
1193 if (err)
1194 return 0;
1195
1196 spin_lock(&hugetlb_lock);
1197 h->nr_overcommit_huge_pages = input;
1198 spin_unlock(&hugetlb_lock);
1199
1200 return count;
1201}
1202HSTATE_ATTR(nr_overcommit_hugepages);
1203
1204static ssize_t free_hugepages_show(struct kobject *kobj,
1205 struct kobj_attribute *attr, char *buf)
1206{
1207 struct hstate *h = kobj_to_hstate(kobj);
1208 return sprintf(buf, "%lu\n", h->free_huge_pages);
1209}
1210HSTATE_ATTR_RO(free_hugepages);
1211
1212static ssize_t resv_hugepages_show(struct kobject *kobj,
1213 struct kobj_attribute *attr, char *buf)
1214{
1215 struct hstate *h = kobj_to_hstate(kobj);
1216 return sprintf(buf, "%lu\n", h->resv_huge_pages);
1217}
1218HSTATE_ATTR_RO(resv_hugepages);
1219
1220static ssize_t surplus_hugepages_show(struct kobject *kobj,
1221 struct kobj_attribute *attr, char *buf)
1222{
1223 struct hstate *h = kobj_to_hstate(kobj);
1224 return sprintf(buf, "%lu\n", h->surplus_huge_pages);
1225}
1226HSTATE_ATTR_RO(surplus_hugepages);
1227
1228static struct attribute *hstate_attrs[] = {
1229 &nr_hugepages_attr.attr,
1230 &nr_overcommit_hugepages_attr.attr,
1231 &free_hugepages_attr.attr,
1232 &resv_hugepages_attr.attr,
1233 &surplus_hugepages_attr.attr,
1234 NULL,
1235};
1236
1237static struct attribute_group hstate_attr_group = {
1238 .attrs = hstate_attrs,
1239};
1240
1241static int __init hugetlb_sysfs_add_hstate(struct hstate *h)
1242{
1243 int retval;
1244
1245 hstate_kobjs[h - hstates] = kobject_create_and_add(h->name,
1246 hugepages_kobj);
1247 if (!hstate_kobjs[h - hstates])
1248 return -ENOMEM;
1249
1250 retval = sysfs_create_group(hstate_kobjs[h - hstates],
1251 &hstate_attr_group);
1252 if (retval)
1253 kobject_put(hstate_kobjs[h - hstates]);
1254
1255 return retval;
1256}
1257
1258static void __init hugetlb_sysfs_init(void)
1259{
1260 struct hstate *h;
1261 int err;
1262
1263 hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj);
1264 if (!hugepages_kobj)
1265 return;
1266
1267 for_each_hstate(h) {
1268 err = hugetlb_sysfs_add_hstate(h);
1269 if (err)
1270 printk(KERN_ERR "Hugetlb: Unable to add hstate %s",
1271 h->name);
1272 }
1273}
1274
1275static void __exit hugetlb_exit(void)
1276{
1277 struct hstate *h;
1278
1279 for_each_hstate(h) {
1280 kobject_put(hstate_kobjs[h - hstates]);
1281 }
1282
1283 kobject_put(hugepages_kobj);
1284}
1285module_exit(hugetlb_exit);
1286
1287static int __init hugetlb_init(void)
1288{
1289 BUILD_BUG_ON(HPAGE_SHIFT == 0);
1290
1291 if (!size_to_hstate(HPAGE_SIZE)) {
1292 hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
1293 parsed_hstate->max_huge_pages = default_hstate_max_huge_pages;
1294 }
1295 default_hstate_idx = size_to_hstate(HPAGE_SIZE) - hstates;
1296
1297 hugetlb_init_hstates();
1298
Andi Kleenaa888a72008-07-23 21:27:47 -07001299 gather_bootmem_prealloc();
1300
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001301 report_hugepages();
1302
1303 hugetlb_sysfs_init();
1304
1305 return 0;
1306}
1307module_init(hugetlb_init);
1308
1309/* Should be called on processing a hugepagesz=... option */
1310void __init hugetlb_add_hstate(unsigned order)
1311{
1312 struct hstate *h;
Andi Kleen8faa8b02008-07-23 21:27:48 -07001313 unsigned long i;
1314
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001315 if (size_to_hstate(PAGE_SIZE << order)) {
1316 printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n");
1317 return;
1318 }
1319 BUG_ON(max_hstate >= HUGE_MAX_HSTATE);
1320 BUG_ON(order == 0);
1321 h = &hstates[max_hstate++];
1322 h->order = order;
1323 h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1);
Andi Kleen8faa8b02008-07-23 21:27:48 -07001324 h->nr_huge_pages = 0;
1325 h->free_huge_pages = 0;
1326 for (i = 0; i < MAX_NUMNODES; ++i)
1327 INIT_LIST_HEAD(&h->hugepage_freelists[i]);
1328 h->hugetlb_next_nid = first_node(node_online_map);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001329 snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
1330 huge_page_size(h)/1024);
Andi Kleen8faa8b02008-07-23 21:27:48 -07001331
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001332 parsed_hstate = h;
1333}
1334
1335static int __init hugetlb_setup(char *s)
1336{
1337 unsigned long *mhp;
Andi Kleen8faa8b02008-07-23 21:27:48 -07001338 static unsigned long *last_mhp;
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001339
1340 /*
1341 * !max_hstate means we haven't parsed a hugepagesz= parameter yet,
1342 * so this hugepages= parameter goes to the "default hstate".
1343 */
1344 if (!max_hstate)
1345 mhp = &default_hstate_max_huge_pages;
1346 else
1347 mhp = &parsed_hstate->max_huge_pages;
1348
Andi Kleen8faa8b02008-07-23 21:27:48 -07001349 if (mhp == last_mhp) {
1350 printk(KERN_WARNING "hugepages= specified twice without "
1351 "interleaving hugepagesz=, ignoring\n");
1352 return 1;
1353 }
1354
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001355 if (sscanf(s, "%lu", mhp) <= 0)
1356 *mhp = 0;
1357
Andi Kleen8faa8b02008-07-23 21:27:48 -07001358 /*
1359 * Global state is always initialized later in hugetlb_init.
1360 * But we need to allocate >= MAX_ORDER hstates here early to still
1361 * use the bootmem allocator.
1362 */
1363 if (max_hstate && parsed_hstate->order >= MAX_ORDER)
1364 hugetlb_hstate_alloc_pages(parsed_hstate);
1365
1366 last_mhp = mhp;
1367
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001368 return 1;
1369}
1370__setup("hugepages=", hugetlb_setup);
1371
1372static unsigned int cpuset_mems_nr(unsigned int *array)
1373{
1374 int node;
1375 unsigned int nr = 0;
1376
1377 for_each_node_mask(node, cpuset_current_mems_allowed)
1378 nr += array[node];
1379
1380 return nr;
1381}
1382
Linus Torvalds1da177e2005-04-16 15:20:36 -07001383int hugetlb_sysctl_handler(struct ctl_table *table, int write,
1384 struct file *file, void __user *buffer,
1385 size_t *length, loff_t *ppos)
1386{
Andi Kleene5ff2152008-07-23 21:27:42 -07001387 struct hstate *h = &default_hstate;
1388 unsigned long tmp;
1389
1390 if (!write)
1391 tmp = h->max_huge_pages;
1392
1393 table->data = &tmp;
1394 table->maxlen = sizeof(unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001395 proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
Andi Kleene5ff2152008-07-23 21:27:42 -07001396
1397 if (write)
1398 h->max_huge_pages = set_max_huge_pages(h, tmp);
1399
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400 return 0;
1401}
Mel Gorman396faf02007-07-17 04:03:13 -07001402
1403int hugetlb_treat_movable_handler(struct ctl_table *table, int write,
1404 struct file *file, void __user *buffer,
1405 size_t *length, loff_t *ppos)
1406{
1407 proc_dointvec(table, write, file, buffer, length, ppos);
1408 if (hugepages_treat_as_movable)
1409 htlb_alloc_mask = GFP_HIGHUSER_MOVABLE;
1410 else
1411 htlb_alloc_mask = GFP_HIGHUSER;
1412 return 0;
1413}
1414
Nishanth Aravamudana3d0c6a2008-02-08 04:18:18 -08001415int hugetlb_overcommit_handler(struct ctl_table *table, int write,
1416 struct file *file, void __user *buffer,
1417 size_t *length, loff_t *ppos)
1418{
Andi Kleena5516432008-07-23 21:27:41 -07001419 struct hstate *h = &default_hstate;
Andi Kleene5ff2152008-07-23 21:27:42 -07001420 unsigned long tmp;
1421
1422 if (!write)
1423 tmp = h->nr_overcommit_huge_pages;
1424
1425 table->data = &tmp;
1426 table->maxlen = sizeof(unsigned long);
Nishanth Aravamudana3d0c6a2008-02-08 04:18:18 -08001427 proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
Andi Kleene5ff2152008-07-23 21:27:42 -07001428
1429 if (write) {
1430 spin_lock(&hugetlb_lock);
1431 h->nr_overcommit_huge_pages = tmp;
1432 spin_unlock(&hugetlb_lock);
1433 }
1434
Nishanth Aravamudana3d0c6a2008-02-08 04:18:18 -08001435 return 0;
1436}
1437
Linus Torvalds1da177e2005-04-16 15:20:36 -07001438#endif /* CONFIG_SYSCTL */
1439
1440int hugetlb_report_meminfo(char *buf)
1441{
Andi Kleena5516432008-07-23 21:27:41 -07001442 struct hstate *h = &default_hstate;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001443 return sprintf(buf,
1444 "HugePages_Total: %5lu\n"
1445 "HugePages_Free: %5lu\n"
Chen, Kenneth Wa43a8c32006-06-23 02:03:15 -07001446 "HugePages_Rsvd: %5lu\n"
Adam Litke7893d1d2007-10-16 01:26:18 -07001447 "HugePages_Surp: %5lu\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001448 "Hugepagesize: %5lu kB\n",
Andi Kleena5516432008-07-23 21:27:41 -07001449 h->nr_huge_pages,
1450 h->free_huge_pages,
1451 h->resv_huge_pages,
1452 h->surplus_huge_pages,
1453 1UL << (huge_page_order(h) + PAGE_SHIFT - 10));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001454}
1455
1456int hugetlb_report_node_meminfo(int nid, char *buf)
1457{
Andi Kleena5516432008-07-23 21:27:41 -07001458 struct hstate *h = &default_hstate;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001459 return sprintf(buf,
1460 "Node %d HugePages_Total: %5u\n"
Nishanth Aravamudana1de0912008-03-26 14:37:53 -07001461 "Node %d HugePages_Free: %5u\n"
1462 "Node %d HugePages_Surp: %5u\n",
Andi Kleena5516432008-07-23 21:27:41 -07001463 nid, h->nr_huge_pages_node[nid],
1464 nid, h->free_huge_pages_node[nid],
1465 nid, h->surplus_huge_pages_node[nid]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001466}
1467
Linus Torvalds1da177e2005-04-16 15:20:36 -07001468/* Return the number pages of memory we physically have, in PAGE_SIZE units. */
1469unsigned long hugetlb_total_pages(void)
1470{
Andi Kleena5516432008-07-23 21:27:41 -07001471 struct hstate *h = &default_hstate;
1472 return h->nr_huge_pages * pages_per_huge_page(h);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001473}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001474
Andi Kleena5516432008-07-23 21:27:41 -07001475static int hugetlb_acct_memory(struct hstate *h, long delta)
Mel Gormanfc1b8a72008-07-23 21:27:22 -07001476{
1477 int ret = -ENOMEM;
1478
1479 spin_lock(&hugetlb_lock);
1480 /*
1481 * When cpuset is configured, it breaks the strict hugetlb page
1482 * reservation as the accounting is done on a global variable. Such
1483 * reservation is completely rubbish in the presence of cpuset because
1484 * the reservation is not checked against page availability for the
1485 * current cpuset. Application can still potentially OOM'ed by kernel
1486 * with lack of free htlb page in cpuset that the task is in.
1487 * Attempt to enforce strict accounting with cpuset is almost
1488 * impossible (or too ugly) because cpuset is too fluid that
1489 * task or memory node can be dynamically moved between cpusets.
1490 *
1491 * The change of semantics for shared hugetlb mapping with cpuset is
1492 * undesirable. However, in order to preserve some of the semantics,
1493 * we fall back to check against current free page availability as
1494 * a best attempt and hopefully to minimize the impact of changing
1495 * semantics that cpuset has.
1496 */
1497 if (delta > 0) {
Andi Kleena5516432008-07-23 21:27:41 -07001498 if (gather_surplus_pages(h, delta) < 0)
Mel Gormanfc1b8a72008-07-23 21:27:22 -07001499 goto out;
1500
Andi Kleena5516432008-07-23 21:27:41 -07001501 if (delta > cpuset_mems_nr(h->free_huge_pages_node)) {
1502 return_unused_surplus_pages(h, delta);
Mel Gormanfc1b8a72008-07-23 21:27:22 -07001503 goto out;
1504 }
1505 }
1506
1507 ret = 0;
1508 if (delta < 0)
Andi Kleena5516432008-07-23 21:27:41 -07001509 return_unused_surplus_pages(h, (unsigned long) -delta);
Mel Gormanfc1b8a72008-07-23 21:27:22 -07001510
1511out:
1512 spin_unlock(&hugetlb_lock);
1513 return ret;
1514}
1515
Andy Whitcroft84afd992008-07-23 21:27:32 -07001516static void hugetlb_vm_op_open(struct vm_area_struct *vma)
1517{
1518 struct resv_map *reservations = vma_resv_map(vma);
1519
1520 /*
1521 * This new VMA should share its siblings reservation map if present.
1522 * The VMA will only ever have a valid reservation map pointer where
1523 * it is being copied for another still existing VMA. As that VMA
1524 * has a reference to the reservation map it cannot dissappear until
1525 * after this open call completes. It is therefore safe to take a
1526 * new reference here without additional locking.
1527 */
1528 if (reservations)
1529 kref_get(&reservations->refs);
1530}
1531
Mel Gormana1e78772008-07-23 21:27:23 -07001532static void hugetlb_vm_op_close(struct vm_area_struct *vma)
1533{
Andi Kleena5516432008-07-23 21:27:41 -07001534 struct hstate *h = hstate_vma(vma);
Andy Whitcroft84afd992008-07-23 21:27:32 -07001535 struct resv_map *reservations = vma_resv_map(vma);
1536 unsigned long reserve;
1537 unsigned long start;
1538 unsigned long end;
1539
1540 if (reservations) {
Andi Kleena5516432008-07-23 21:27:41 -07001541 start = vma_hugecache_offset(h, vma, vma->vm_start);
1542 end = vma_hugecache_offset(h, vma, vma->vm_end);
Andy Whitcroft84afd992008-07-23 21:27:32 -07001543
1544 reserve = (end - start) -
1545 region_count(&reservations->regions, start, end);
1546
1547 kref_put(&reservations->refs, resv_map_release);
1548
1549 if (reserve)
Andi Kleena5516432008-07-23 21:27:41 -07001550 hugetlb_acct_memory(h, -reserve);
Andy Whitcroft84afd992008-07-23 21:27:32 -07001551 }
Mel Gormana1e78772008-07-23 21:27:23 -07001552}
1553
Linus Torvalds1da177e2005-04-16 15:20:36 -07001554/*
1555 * We cannot handle pagefaults against hugetlb pages at all. They cause
1556 * handle_mm_fault() to try to instantiate regular-sized pages in the
1557 * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get
1558 * this far.
1559 */
Nick Piggind0217ac2007-07-19 01:47:03 -07001560static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001561{
1562 BUG();
Nick Piggind0217ac2007-07-19 01:47:03 -07001563 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001564}
1565
1566struct vm_operations_struct hugetlb_vm_ops = {
Nick Piggind0217ac2007-07-19 01:47:03 -07001567 .fault = hugetlb_vm_op_fault,
Andy Whitcroft84afd992008-07-23 21:27:32 -07001568 .open = hugetlb_vm_op_open,
Mel Gormana1e78772008-07-23 21:27:23 -07001569 .close = hugetlb_vm_op_close,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001570};
1571
David Gibson1e8f8892006-01-06 00:10:44 -08001572static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page,
1573 int writable)
David Gibson63551ae2005-06-21 17:14:44 -07001574{
1575 pte_t entry;
1576
David Gibson1e8f8892006-01-06 00:10:44 -08001577 if (writable) {
David Gibson63551ae2005-06-21 17:14:44 -07001578 entry =
1579 pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
1580 } else {
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07001581 entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot));
David Gibson63551ae2005-06-21 17:14:44 -07001582 }
1583 entry = pte_mkyoung(entry);
1584 entry = pte_mkhuge(entry);
1585
1586 return entry;
1587}
1588
David Gibson1e8f8892006-01-06 00:10:44 -08001589static void set_huge_ptep_writable(struct vm_area_struct *vma,
1590 unsigned long address, pte_t *ptep)
1591{
1592 pte_t entry;
1593
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07001594 entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep)));
1595 if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) {
Benjamin Herrenschmidt8dab5242007-06-16 10:16:12 -07001596 update_mmu_cache(vma, address, entry);
Benjamin Herrenschmidt8dab5242007-06-16 10:16:12 -07001597 }
David Gibson1e8f8892006-01-06 00:10:44 -08001598}
1599
1600
David Gibson63551ae2005-06-21 17:14:44 -07001601int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
1602 struct vm_area_struct *vma)
1603{
1604 pte_t *src_pte, *dst_pte, entry;
1605 struct page *ptepage;
Hugh Dickins1c598272005-10-19 21:23:43 -07001606 unsigned long addr;
David Gibson1e8f8892006-01-06 00:10:44 -08001607 int cow;
Andi Kleena5516432008-07-23 21:27:41 -07001608 struct hstate *h = hstate_vma(vma);
1609 unsigned long sz = huge_page_size(h);
David Gibson1e8f8892006-01-06 00:10:44 -08001610
1611 cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
David Gibson63551ae2005-06-21 17:14:44 -07001612
Andi Kleena5516432008-07-23 21:27:41 -07001613 for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
Hugh Dickinsc74df322005-10-29 18:16:23 -07001614 src_pte = huge_pte_offset(src, addr);
1615 if (!src_pte)
1616 continue;
Andi Kleena5516432008-07-23 21:27:41 -07001617 dst_pte = huge_pte_alloc(dst, addr, sz);
David Gibson63551ae2005-06-21 17:14:44 -07001618 if (!dst_pte)
1619 goto nomem;
Larry Woodmanc5c99422008-01-24 05:49:25 -08001620
1621 /* If the pagetables are shared don't copy or take references */
1622 if (dst_pte == src_pte)
1623 continue;
1624
Hugh Dickinsc74df322005-10-29 18:16:23 -07001625 spin_lock(&dst->page_table_lock);
Nick Piggin46478752008-06-05 22:45:57 -07001626 spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING);
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07001627 if (!huge_pte_none(huge_ptep_get(src_pte))) {
David Gibson1e8f8892006-01-06 00:10:44 -08001628 if (cow)
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07001629 huge_ptep_set_wrprotect(src, addr, src_pte);
1630 entry = huge_ptep_get(src_pte);
Hugh Dickins1c598272005-10-19 21:23:43 -07001631 ptepage = pte_page(entry);
1632 get_page(ptepage);
Hugh Dickins1c598272005-10-19 21:23:43 -07001633 set_huge_pte_at(dst, addr, dst_pte, entry);
1634 }
1635 spin_unlock(&src->page_table_lock);
Hugh Dickinsc74df322005-10-29 18:16:23 -07001636 spin_unlock(&dst->page_table_lock);
David Gibson63551ae2005-06-21 17:14:44 -07001637 }
1638 return 0;
1639
1640nomem:
1641 return -ENOMEM;
1642}
1643
Chen, Kenneth W502717f2006-10-11 01:20:46 -07001644void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001645 unsigned long end, struct page *ref_page)
David Gibson63551ae2005-06-21 17:14:44 -07001646{
1647 struct mm_struct *mm = vma->vm_mm;
1648 unsigned long address;
David Gibsonc7546f82005-08-05 11:59:35 -07001649 pte_t *ptep;
David Gibson63551ae2005-06-21 17:14:44 -07001650 pte_t pte;
1651 struct page *page;
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07001652 struct page *tmp;
Andi Kleena5516432008-07-23 21:27:41 -07001653 struct hstate *h = hstate_vma(vma);
1654 unsigned long sz = huge_page_size(h);
1655
Chen, Kenneth Wc0a499c2006-12-06 20:31:39 -08001656 /*
1657 * A page gathering list, protected by per file i_mmap_lock. The
1658 * lock is used to avoid list corruption from multiple unmapping
1659 * of the same page since we are using page->lru.
1660 */
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07001661 LIST_HEAD(page_list);
David Gibson63551ae2005-06-21 17:14:44 -07001662
1663 WARN_ON(!is_vm_hugetlb_page(vma));
Andi Kleena5516432008-07-23 21:27:41 -07001664 BUG_ON(start & ~huge_page_mask(h));
1665 BUG_ON(end & ~huge_page_mask(h));
David Gibson63551ae2005-06-21 17:14:44 -07001666
Hugh Dickins508034a2005-10-29 18:16:30 -07001667 spin_lock(&mm->page_table_lock);
Andi Kleena5516432008-07-23 21:27:41 -07001668 for (address = start; address < end; address += sz) {
David Gibsonc7546f82005-08-05 11:59:35 -07001669 ptep = huge_pte_offset(mm, address);
Adam Litke4c887262005-10-29 18:16:46 -07001670 if (!ptep)
David Gibsonc7546f82005-08-05 11:59:35 -07001671 continue;
1672
Chen, Kenneth W39dde652006-12-06 20:32:03 -08001673 if (huge_pmd_unshare(mm, &address, ptep))
1674 continue;
1675
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001676 /*
1677 * If a reference page is supplied, it is because a specific
1678 * page is being unmapped, not a range. Ensure the page we
1679 * are about to unmap is the actual page of interest.
1680 */
1681 if (ref_page) {
1682 pte = huge_ptep_get(ptep);
1683 if (huge_pte_none(pte))
1684 continue;
1685 page = pte_page(pte);
1686 if (page != ref_page)
1687 continue;
1688
1689 /*
1690 * Mark the VMA as having unmapped its page so that
1691 * future faults in this VMA will fail rather than
1692 * looking like data was lost
1693 */
1694 set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED);
1695 }
1696
David Gibsonc7546f82005-08-05 11:59:35 -07001697 pte = huge_ptep_get_and_clear(mm, address, ptep);
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07001698 if (huge_pte_none(pte))
David Gibson63551ae2005-06-21 17:14:44 -07001699 continue;
David Gibsonc7546f82005-08-05 11:59:35 -07001700
David Gibson63551ae2005-06-21 17:14:44 -07001701 page = pte_page(pte);
Ken Chen6649a382007-02-08 14:20:27 -08001702 if (pte_dirty(pte))
1703 set_page_dirty(page);
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07001704 list_add(&page->lru, &page_list);
David Gibson63551ae2005-06-21 17:14:44 -07001705 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001706 spin_unlock(&mm->page_table_lock);
Hugh Dickins508034a2005-10-29 18:16:30 -07001707 flush_tlb_range(vma, start, end);
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07001708 list_for_each_entry_safe(page, tmp, &page_list, lru) {
1709 list_del(&page->lru);
1710 put_page(page);
1711 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001712}
David Gibson63551ae2005-06-21 17:14:44 -07001713
Chen, Kenneth W502717f2006-10-11 01:20:46 -07001714void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001715 unsigned long end, struct page *ref_page)
Chen, Kenneth W502717f2006-10-11 01:20:46 -07001716{
Andi Kleena137e1c2008-07-23 21:27:43 -07001717 spin_lock(&vma->vm_file->f_mapping->i_mmap_lock);
1718 __unmap_hugepage_range(vma, start, end, ref_page);
1719 spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock);
Chen, Kenneth W502717f2006-10-11 01:20:46 -07001720}
1721
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001722/*
1723 * This is called when the original mapper is failing to COW a MAP_PRIVATE
1724 * mappping it owns the reserve page for. The intention is to unmap the page
1725 * from other VMAs and let the children be SIGKILLed if they are faulting the
1726 * same region.
1727 */
1728int unmap_ref_private(struct mm_struct *mm,
1729 struct vm_area_struct *vma,
1730 struct page *page,
1731 unsigned long address)
1732{
1733 struct vm_area_struct *iter_vma;
1734 struct address_space *mapping;
1735 struct prio_tree_iter iter;
1736 pgoff_t pgoff;
1737
1738 /*
1739 * vm_pgoff is in PAGE_SIZE units, hence the different calculation
1740 * from page cache lookup which is in HPAGE_SIZE units.
1741 */
1742 address = address & huge_page_mask(hstate_vma(vma));
1743 pgoff = ((address - vma->vm_start) >> PAGE_SHIFT)
1744 + (vma->vm_pgoff >> PAGE_SHIFT);
1745 mapping = (struct address_space *)page_private(page);
1746
1747 vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
1748 /* Do not unmap the current VMA */
1749 if (iter_vma == vma)
1750 continue;
1751
1752 /*
1753 * Unmap the page from other VMAs without their own reserves.
1754 * They get marked to be SIGKILLed if they fault in these
1755 * areas. This is because a future no-page fault on this VMA
1756 * could insert a zeroed page instead of the data existing
1757 * from the time of fork. This would look like data corruption
1758 */
1759 if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER))
1760 unmap_hugepage_range(iter_vma,
1761 address, address + HPAGE_SIZE,
1762 page);
1763 }
1764
1765 return 1;
1766}
1767
David Gibson1e8f8892006-01-06 00:10:44 -08001768static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001769 unsigned long address, pte_t *ptep, pte_t pte,
1770 struct page *pagecache_page)
David Gibson1e8f8892006-01-06 00:10:44 -08001771{
Andi Kleena5516432008-07-23 21:27:41 -07001772 struct hstate *h = hstate_vma(vma);
David Gibson1e8f8892006-01-06 00:10:44 -08001773 struct page *old_page, *new_page;
David Gibson79ac6ba2006-03-22 00:08:51 -08001774 int avoidcopy;
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001775 int outside_reserve = 0;
David Gibson1e8f8892006-01-06 00:10:44 -08001776
1777 old_page = pte_page(pte);
1778
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001779retry_avoidcopy:
David Gibson1e8f8892006-01-06 00:10:44 -08001780 /* If no-one else is actually using this page, avoid the copy
1781 * and just make the page writable */
1782 avoidcopy = (page_count(old_page) == 1);
1783 if (avoidcopy) {
1784 set_huge_ptep_writable(vma, address, ptep);
Nick Piggin83c54072007-07-19 01:47:05 -07001785 return 0;
David Gibson1e8f8892006-01-06 00:10:44 -08001786 }
1787
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001788 /*
1789 * If the process that created a MAP_PRIVATE mapping is about to
1790 * perform a COW due to a shared page count, attempt to satisfy
1791 * the allocation without using the existing reserves. The pagecache
1792 * page is used to determine if the reserve at this address was
1793 * consumed or not. If reserves were used, a partial faulted mapping
1794 * at the time of fork() could consume its reserves on COW instead
1795 * of the full address range.
1796 */
1797 if (!(vma->vm_flags & VM_SHARED) &&
1798 is_vma_resv_set(vma, HPAGE_RESV_OWNER) &&
1799 old_page != pagecache_page)
1800 outside_reserve = 1;
1801
David Gibson1e8f8892006-01-06 00:10:44 -08001802 page_cache_get(old_page);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001803 new_page = alloc_huge_page(vma, address, outside_reserve);
David Gibson1e8f8892006-01-06 00:10:44 -08001804
Adam Litke2fc39ce2007-11-14 16:59:39 -08001805 if (IS_ERR(new_page)) {
David Gibson1e8f8892006-01-06 00:10:44 -08001806 page_cache_release(old_page);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001807
1808 /*
1809 * If a process owning a MAP_PRIVATE mapping fails to COW,
1810 * it is due to references held by a child and an insufficient
1811 * huge page pool. To guarantee the original mappers
1812 * reliability, unmap the page from child processes. The child
1813 * may get SIGKILLed if it later faults.
1814 */
1815 if (outside_reserve) {
1816 BUG_ON(huge_pte_none(pte));
1817 if (unmap_ref_private(mm, vma, old_page, address)) {
1818 BUG_ON(page_count(old_page) != 1);
1819 BUG_ON(huge_pte_none(pte));
1820 goto retry_avoidcopy;
1821 }
1822 WARN_ON_ONCE(1);
1823 }
1824
Adam Litke2fc39ce2007-11-14 16:59:39 -08001825 return -PTR_ERR(new_page);
David Gibson1e8f8892006-01-06 00:10:44 -08001826 }
1827
1828 spin_unlock(&mm->page_table_lock);
Atsushi Nemoto9de455b2006-12-12 17:14:55 +00001829 copy_huge_page(new_page, old_page, address, vma);
Nick Piggin0ed361d2008-02-04 22:29:34 -08001830 __SetPageUptodate(new_page);
David Gibson1e8f8892006-01-06 00:10:44 -08001831 spin_lock(&mm->page_table_lock);
1832
Andi Kleena5516432008-07-23 21:27:41 -07001833 ptep = huge_pte_offset(mm, address & huge_page_mask(h));
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07001834 if (likely(pte_same(huge_ptep_get(ptep), pte))) {
David Gibson1e8f8892006-01-06 00:10:44 -08001835 /* Break COW */
Gerald Schaefer8fe627e2008-04-28 02:13:28 -07001836 huge_ptep_clear_flush(vma, address, ptep);
David Gibson1e8f8892006-01-06 00:10:44 -08001837 set_huge_pte_at(mm, address, ptep,
1838 make_huge_pte(vma, new_page, 1));
1839 /* Make the old page be freed below */
1840 new_page = old_page;
1841 }
1842 page_cache_release(new_page);
1843 page_cache_release(old_page);
Nick Piggin83c54072007-07-19 01:47:05 -07001844 return 0;
David Gibson1e8f8892006-01-06 00:10:44 -08001845}
1846
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001847/* Return the pagecache page at a given address within a VMA */
Andi Kleena5516432008-07-23 21:27:41 -07001848static struct page *hugetlbfs_pagecache_page(struct hstate *h,
1849 struct vm_area_struct *vma, unsigned long address)
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001850{
1851 struct address_space *mapping;
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -07001852 pgoff_t idx;
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001853
1854 mapping = vma->vm_file->f_mapping;
Andi Kleena5516432008-07-23 21:27:41 -07001855 idx = vma_hugecache_offset(h, vma, address);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001856
1857 return find_lock_page(mapping, idx);
1858}
1859
Robert P. J. Daya1ed3dd2007-07-17 04:03:33 -07001860static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
David Gibson1e8f8892006-01-06 00:10:44 -08001861 unsigned long address, pte_t *ptep, int write_access)
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01001862{
Andi Kleena5516432008-07-23 21:27:41 -07001863 struct hstate *h = hstate_vma(vma);
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01001864 int ret = VM_FAULT_SIGBUS;
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -07001865 pgoff_t idx;
Adam Litke4c887262005-10-29 18:16:46 -07001866 unsigned long size;
Adam Litke4c887262005-10-29 18:16:46 -07001867 struct page *page;
1868 struct address_space *mapping;
David Gibson1e8f8892006-01-06 00:10:44 -08001869 pte_t new_pte;
Adam Litke4c887262005-10-29 18:16:46 -07001870
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001871 /*
1872 * Currently, we are forced to kill the process in the event the
1873 * original mapper has unmapped pages from the child due to a failed
1874 * COW. Warn that such a situation has occured as it may not be obvious
1875 */
1876 if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) {
1877 printk(KERN_WARNING
1878 "PID %d killed due to inadequate hugepage pool\n",
1879 current->pid);
1880 return ret;
1881 }
1882
Adam Litke4c887262005-10-29 18:16:46 -07001883 mapping = vma->vm_file->f_mapping;
Andi Kleena5516432008-07-23 21:27:41 -07001884 idx = vma_hugecache_offset(h, vma, address);
Adam Litke4c887262005-10-29 18:16:46 -07001885
1886 /*
1887 * Use page lock to guard against racing truncation
1888 * before we get page_table_lock.
1889 */
Christoph Lameter6bda6662006-01-06 00:10:49 -08001890retry:
1891 page = find_lock_page(mapping, idx);
1892 if (!page) {
Andi Kleena5516432008-07-23 21:27:41 -07001893 size = i_size_read(mapping->host) >> huge_page_shift(h);
Hugh Dickinsebed4bf2006-10-28 10:38:43 -07001894 if (idx >= size)
1895 goto out;
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001896 page = alloc_huge_page(vma, address, 0);
Adam Litke2fc39ce2007-11-14 16:59:39 -08001897 if (IS_ERR(page)) {
1898 ret = -PTR_ERR(page);
Christoph Lameter6bda6662006-01-06 00:10:49 -08001899 goto out;
1900 }
Andi Kleena5516432008-07-23 21:27:41 -07001901 clear_huge_page(page, address, huge_page_size(h));
Nick Piggin0ed361d2008-02-04 22:29:34 -08001902 __SetPageUptodate(page);
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01001903
Christoph Lameter6bda6662006-01-06 00:10:49 -08001904 if (vma->vm_flags & VM_SHARED) {
1905 int err;
Ken Chen45c682a2007-11-14 16:59:44 -08001906 struct inode *inode = mapping->host;
Christoph Lameter6bda6662006-01-06 00:10:49 -08001907
1908 err = add_to_page_cache(page, mapping, idx, GFP_KERNEL);
1909 if (err) {
1910 put_page(page);
Christoph Lameter6bda6662006-01-06 00:10:49 -08001911 if (err == -EEXIST)
1912 goto retry;
1913 goto out;
1914 }
Ken Chen45c682a2007-11-14 16:59:44 -08001915
1916 spin_lock(&inode->i_lock);
Andi Kleena5516432008-07-23 21:27:41 -07001917 inode->i_blocks += blocks_per_huge_page(h);
Ken Chen45c682a2007-11-14 16:59:44 -08001918 spin_unlock(&inode->i_lock);
Christoph Lameter6bda6662006-01-06 00:10:49 -08001919 } else
1920 lock_page(page);
1921 }
David Gibson1e8f8892006-01-06 00:10:44 -08001922
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01001923 spin_lock(&mm->page_table_lock);
Andi Kleena5516432008-07-23 21:27:41 -07001924 size = i_size_read(mapping->host) >> huge_page_shift(h);
Adam Litke4c887262005-10-29 18:16:46 -07001925 if (idx >= size)
1926 goto backout;
1927
Nick Piggin83c54072007-07-19 01:47:05 -07001928 ret = 0;
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07001929 if (!huge_pte_none(huge_ptep_get(ptep)))
Adam Litke4c887262005-10-29 18:16:46 -07001930 goto backout;
1931
David Gibson1e8f8892006-01-06 00:10:44 -08001932 new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE)
1933 && (vma->vm_flags & VM_SHARED)));
1934 set_huge_pte_at(mm, address, ptep, new_pte);
1935
1936 if (write_access && !(vma->vm_flags & VM_SHARED)) {
1937 /* Optimization, do the COW without a second fault */
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001938 ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page);
David Gibson1e8f8892006-01-06 00:10:44 -08001939 }
1940
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01001941 spin_unlock(&mm->page_table_lock);
Adam Litke4c887262005-10-29 18:16:46 -07001942 unlock_page(page);
1943out:
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01001944 return ret;
Adam Litke4c887262005-10-29 18:16:46 -07001945
1946backout:
1947 spin_unlock(&mm->page_table_lock);
Adam Litke4c887262005-10-29 18:16:46 -07001948 unlock_page(page);
1949 put_page(page);
1950 goto out;
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01001951}
1952
Adam Litke86e52162006-01-06 00:10:43 -08001953int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
1954 unsigned long address, int write_access)
1955{
1956 pte_t *ptep;
1957 pte_t entry;
David Gibson1e8f8892006-01-06 00:10:44 -08001958 int ret;
David Gibson3935baa2006-03-22 00:08:53 -08001959 static DEFINE_MUTEX(hugetlb_instantiation_mutex);
Andi Kleena5516432008-07-23 21:27:41 -07001960 struct hstate *h = hstate_vma(vma);
Adam Litke86e52162006-01-06 00:10:43 -08001961
Andi Kleena5516432008-07-23 21:27:41 -07001962 ptep = huge_pte_alloc(mm, address, huge_page_size(h));
Adam Litke86e52162006-01-06 00:10:43 -08001963 if (!ptep)
1964 return VM_FAULT_OOM;
1965
David Gibson3935baa2006-03-22 00:08:53 -08001966 /*
1967 * Serialize hugepage allocation and instantiation, so that we don't
1968 * get spurious allocation failures if two CPUs race to instantiate
1969 * the same page in the page cache.
1970 */
1971 mutex_lock(&hugetlb_instantiation_mutex);
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07001972 entry = huge_ptep_get(ptep);
1973 if (huge_pte_none(entry)) {
David Gibson3935baa2006-03-22 00:08:53 -08001974 ret = hugetlb_no_page(mm, vma, address, ptep, write_access);
1975 mutex_unlock(&hugetlb_instantiation_mutex);
1976 return ret;
1977 }
Adam Litke86e52162006-01-06 00:10:43 -08001978
Nick Piggin83c54072007-07-19 01:47:05 -07001979 ret = 0;
David Gibson1e8f8892006-01-06 00:10:44 -08001980
1981 spin_lock(&mm->page_table_lock);
1982 /* Check for a racing update before calling hugetlb_cow */
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07001983 if (likely(pte_same(entry, huge_ptep_get(ptep))))
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001984 if (write_access && !pte_write(entry)) {
1985 struct page *page;
Andi Kleena5516432008-07-23 21:27:41 -07001986 page = hugetlbfs_pagecache_page(h, vma, address);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001987 ret = hugetlb_cow(mm, vma, address, ptep, entry, page);
1988 if (page) {
1989 unlock_page(page);
1990 put_page(page);
1991 }
1992 }
David Gibson1e8f8892006-01-06 00:10:44 -08001993 spin_unlock(&mm->page_table_lock);
David Gibson3935baa2006-03-22 00:08:53 -08001994 mutex_unlock(&hugetlb_instantiation_mutex);
David Gibson1e8f8892006-01-06 00:10:44 -08001995
1996 return ret;
Adam Litke86e52162006-01-06 00:10:43 -08001997}
1998
David Gibson63551ae2005-06-21 17:14:44 -07001999int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
2000 struct page **pages, struct vm_area_struct **vmas,
Adam Litke5b23dbe2007-11-14 16:59:33 -08002001 unsigned long *position, int *length, int i,
2002 int write)
David Gibson63551ae2005-06-21 17:14:44 -07002003{
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002004 unsigned long pfn_offset;
2005 unsigned long vaddr = *position;
David Gibson63551ae2005-06-21 17:14:44 -07002006 int remainder = *length;
Andi Kleena5516432008-07-23 21:27:41 -07002007 struct hstate *h = hstate_vma(vma);
David Gibson63551ae2005-06-21 17:14:44 -07002008
Hugh Dickins1c598272005-10-19 21:23:43 -07002009 spin_lock(&mm->page_table_lock);
David Gibson63551ae2005-06-21 17:14:44 -07002010 while (vaddr < vma->vm_end && remainder) {
Adam Litke4c887262005-10-29 18:16:46 -07002011 pte_t *pte;
2012 struct page *page;
2013
2014 /*
2015 * Some archs (sparc64, sh*) have multiple pte_ts to
2016 * each hugepage. We have to make * sure we get the
2017 * first, for the page indexing below to work.
2018 */
Andi Kleena5516432008-07-23 21:27:41 -07002019 pte = huge_pte_offset(mm, vaddr & huge_page_mask(h));
Adam Litke4c887262005-10-29 18:16:46 -07002020
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002021 if (!pte || huge_pte_none(huge_ptep_get(pte)) ||
2022 (write && !pte_write(huge_ptep_get(pte)))) {
Adam Litke4c887262005-10-29 18:16:46 -07002023 int ret;
2024
2025 spin_unlock(&mm->page_table_lock);
Adam Litke5b23dbe2007-11-14 16:59:33 -08002026 ret = hugetlb_fault(mm, vma, vaddr, write);
Adam Litke4c887262005-10-29 18:16:46 -07002027 spin_lock(&mm->page_table_lock);
Adam Litkea89182c2007-08-22 14:01:51 -07002028 if (!(ret & VM_FAULT_ERROR))
Adam Litke4c887262005-10-29 18:16:46 -07002029 continue;
2030
2031 remainder = 0;
2032 if (!i)
2033 i = -EFAULT;
2034 break;
2035 }
David Gibson63551ae2005-06-21 17:14:44 -07002036
Andi Kleena5516432008-07-23 21:27:41 -07002037 pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT;
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002038 page = pte_page(huge_ptep_get(pte));
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002039same_page:
Chen, Kenneth Wd6692182006-03-31 02:29:57 -08002040 if (pages) {
2041 get_page(page);
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002042 pages[i] = page + pfn_offset;
Chen, Kenneth Wd6692182006-03-31 02:29:57 -08002043 }
David Gibson63551ae2005-06-21 17:14:44 -07002044
2045 if (vmas)
2046 vmas[i] = vma;
2047
2048 vaddr += PAGE_SIZE;
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002049 ++pfn_offset;
David Gibson63551ae2005-06-21 17:14:44 -07002050 --remainder;
2051 ++i;
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002052 if (vaddr < vma->vm_end && remainder &&
Andi Kleena5516432008-07-23 21:27:41 -07002053 pfn_offset < pages_per_huge_page(h)) {
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002054 /*
2055 * We use pfn_offset to avoid touching the pageframes
2056 * of this compound page.
2057 */
2058 goto same_page;
2059 }
David Gibson63551ae2005-06-21 17:14:44 -07002060 }
Hugh Dickins1c598272005-10-19 21:23:43 -07002061 spin_unlock(&mm->page_table_lock);
David Gibson63551ae2005-06-21 17:14:44 -07002062 *length = remainder;
2063 *position = vaddr;
2064
2065 return i;
2066}
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002067
2068void hugetlb_change_protection(struct vm_area_struct *vma,
2069 unsigned long address, unsigned long end, pgprot_t newprot)
2070{
2071 struct mm_struct *mm = vma->vm_mm;
2072 unsigned long start = address;
2073 pte_t *ptep;
2074 pte_t pte;
Andi Kleena5516432008-07-23 21:27:41 -07002075 struct hstate *h = hstate_vma(vma);
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002076
2077 BUG_ON(address >= end);
2078 flush_cache_range(vma, address, end);
2079
Chen, Kenneth W39dde652006-12-06 20:32:03 -08002080 spin_lock(&vma->vm_file->f_mapping->i_mmap_lock);
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002081 spin_lock(&mm->page_table_lock);
Andi Kleena5516432008-07-23 21:27:41 -07002082 for (; address < end; address += huge_page_size(h)) {
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002083 ptep = huge_pte_offset(mm, address);
2084 if (!ptep)
2085 continue;
Chen, Kenneth W39dde652006-12-06 20:32:03 -08002086 if (huge_pmd_unshare(mm, &address, ptep))
2087 continue;
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002088 if (!huge_pte_none(huge_ptep_get(ptep))) {
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002089 pte = huge_ptep_get_and_clear(mm, address, ptep);
2090 pte = pte_mkhuge(pte_modify(pte, newprot));
2091 set_huge_pte_at(mm, address, ptep, pte);
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002092 }
2093 }
2094 spin_unlock(&mm->page_table_lock);
Chen, Kenneth W39dde652006-12-06 20:32:03 -08002095 spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock);
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002096
2097 flush_tlb_range(vma, start, end);
2098}
2099
Mel Gormana1e78772008-07-23 21:27:23 -07002100int hugetlb_reserve_pages(struct inode *inode,
2101 long from, long to,
2102 struct vm_area_struct *vma)
Adam Litkee4e574b2007-10-16 01:26:19 -07002103{
2104 long ret, chg;
Andi Kleena5516432008-07-23 21:27:41 -07002105 struct hstate *h = hstate_inode(inode);
Adam Litkee4e574b2007-10-16 01:26:19 -07002106
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -07002107 if (vma && vma->vm_flags & VM_NORESERVE)
2108 return 0;
2109
Mel Gormana1e78772008-07-23 21:27:23 -07002110 /*
2111 * Shared mappings base their reservation on the number of pages that
2112 * are already allocated on behalf of the file. Private mappings need
2113 * to reserve the full area even if read-only as mprotect() may be
2114 * called to make the mapping read-write. Assume !vma is a shm mapping
2115 */
2116 if (!vma || vma->vm_flags & VM_SHARED)
2117 chg = region_chg(&inode->i_mapping->private_list, from, to);
2118 else {
Andy Whitcroft84afd992008-07-23 21:27:32 -07002119 struct resv_map *resv_map = resv_map_alloc();
2120 if (!resv_map)
2121 return -ENOMEM;
2122
Mel Gormana1e78772008-07-23 21:27:23 -07002123 chg = to - from;
Andy Whitcroft84afd992008-07-23 21:27:32 -07002124
2125 set_vma_resv_map(vma, resv_map);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002126 set_vma_resv_flags(vma, HPAGE_RESV_OWNER);
Mel Gormana1e78772008-07-23 21:27:23 -07002127 }
2128
Adam Litkee4e574b2007-10-16 01:26:19 -07002129 if (chg < 0)
2130 return chg;
Ken Chen8a630112007-05-09 02:33:34 -07002131
Adam Litke90d8b7e2007-11-14 16:59:42 -08002132 if (hugetlb_get_quota(inode->i_mapping, chg))
2133 return -ENOSPC;
Andi Kleena5516432008-07-23 21:27:41 -07002134 ret = hugetlb_acct_memory(h, chg);
Ken Chen68842c92008-01-14 00:55:19 -08002135 if (ret < 0) {
2136 hugetlb_put_quota(inode->i_mapping, chg);
Chen, Kenneth Wa43a8c32006-06-23 02:03:15 -07002137 return ret;
Ken Chen68842c92008-01-14 00:55:19 -08002138 }
Mel Gormana1e78772008-07-23 21:27:23 -07002139 if (!vma || vma->vm_flags & VM_SHARED)
2140 region_add(&inode->i_mapping->private_list, from, to);
Chen, Kenneth Wa43a8c32006-06-23 02:03:15 -07002141 return 0;
2142}
2143
2144void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed)
2145{
Andi Kleena5516432008-07-23 21:27:41 -07002146 struct hstate *h = hstate_inode(inode);
Chen, Kenneth Wa43a8c32006-06-23 02:03:15 -07002147 long chg = region_truncate(&inode->i_mapping->private_list, offset);
Ken Chen45c682a2007-11-14 16:59:44 -08002148
2149 spin_lock(&inode->i_lock);
Andi Kleena5516432008-07-23 21:27:41 -07002150 inode->i_blocks -= blocks_per_huge_page(h);
Ken Chen45c682a2007-11-14 16:59:44 -08002151 spin_unlock(&inode->i_lock);
2152
Adam Litke90d8b7e2007-11-14 16:59:42 -08002153 hugetlb_put_quota(inode->i_mapping, (chg - freed));
Andi Kleena5516432008-07-23 21:27:41 -07002154 hugetlb_acct_memory(h, -(chg - freed));
Chen, Kenneth Wa43a8c32006-06-23 02:03:15 -07002155}