blob: bb28a5f9db8ddbf2f65391fe9206ca99b46a256b [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Generic hugetlb support.
3 * (C) William Irwin, April 2004
4 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07005#include <linux/list.h>
6#include <linux/init.h>
7#include <linux/module.h>
8#include <linux/mm.h>
Alexey Dobriyane1759c22008-10-15 23:50:22 +04009#include <linux/seq_file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/sysctl.h>
11#include <linux/highmem.h>
Andrea Arcangelicddb8a52008-07-28 15:46:29 -070012#include <linux/mmu_notifier.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/nodemask.h>
David Gibson63551ae2005-06-21 17:14:44 -070014#include <linux/pagemap.h>
Christoph Lameter5da7ca82006-01-06 00:10:46 -080015#include <linux/mempolicy.h>
Christoph Lameteraea47ff2006-01-08 01:00:57 -080016#include <linux/cpuset.h>
David Gibson3935baa2006-03-22 00:08:53 -080017#include <linux/mutex.h>
Andi Kleenaa888a72008-07-23 21:27:47 -070018#include <linux/bootmem.h>
Nishanth Aravamudana3437872008-07-23 21:27:44 -070019#include <linux/sysfs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090020#include <linux/slab.h>
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +090021#include <linux/rmap.h>
Naoya Horiguchifd6a03ed2010-05-28 09:29:21 +090022#include <linux/swap.h>
23#include <linux/swapops.h>
Linus Torvaldsd6606682008-08-06 12:04:54 -070024
David Gibson63551ae2005-06-21 17:14:44 -070025#include <asm/page.h>
26#include <asm/pgtable.h>
Chris Forbes32f84522011-07-25 17:12:14 -070027#include <linux/io.h>
David Gibson63551ae2005-06-21 17:14:44 -070028
29#include <linux/hugetlb.h>
Lee Schermerhorn9a305232009-12-14 17:58:25 -080030#include <linux/node.h>
Nick Piggin7835e982006-03-22 00:08:40 -080031#include "internal.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
33const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
Mel Gorman396faf02007-07-17 04:03:13 -070034static gfp_t htlb_alloc_mask = GFP_HIGHUSER;
35unsigned long hugepages_treat_as_movable;
Andi Kleena5516432008-07-23 21:27:41 -070036
Andi Kleene5ff2152008-07-23 21:27:42 -070037static int max_hstate;
38unsigned int default_hstate_idx;
39struct hstate hstates[HUGE_MAX_HSTATE];
40
Jon Tollefson53ba51d2008-07-23 21:27:52 -070041__initdata LIST_HEAD(huge_boot_pages);
42
Andi Kleene5ff2152008-07-23 21:27:42 -070043/* for command line parsing */
44static struct hstate * __initdata parsed_hstate;
45static unsigned long __initdata default_hstate_max_huge_pages;
Nick Piggine11bfbf2008-07-23 21:27:52 -070046static unsigned long __initdata default_hstate_size;
Andi Kleene5ff2152008-07-23 21:27:42 -070047
48#define for_each_hstate(h) \
49 for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++)
Mel Gorman396faf02007-07-17 04:03:13 -070050
David Gibson3935baa2006-03-22 00:08:53 -080051/*
52 * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages
53 */
54static DEFINE_SPINLOCK(hugetlb_lock);
Eric Paris0bd0f9f2005-11-21 21:32:28 -080055
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -070056/*
Andy Whitcroft96822902008-07-23 21:27:29 -070057 * Region tracking -- allows tracking of reservations and instantiated pages
58 * across the pages in a mapping.
Andy Whitcroft84afd992008-07-23 21:27:32 -070059 *
60 * The region data structures are protected by a combination of the mmap_sem
61 * and the hugetlb_instantion_mutex. To access or modify a region the caller
62 * must either hold the mmap_sem for write, or the mmap_sem for read and
63 * the hugetlb_instantiation mutex:
64 *
Chris Forbes32f84522011-07-25 17:12:14 -070065 * down_write(&mm->mmap_sem);
Andy Whitcroft84afd992008-07-23 21:27:32 -070066 * or
Chris Forbes32f84522011-07-25 17:12:14 -070067 * down_read(&mm->mmap_sem);
68 * mutex_lock(&hugetlb_instantiation_mutex);
Andy Whitcroft96822902008-07-23 21:27:29 -070069 */
70struct file_region {
71 struct list_head link;
72 long from;
73 long to;
74};
75
76static long region_add(struct list_head *head, long f, long t)
77{
78 struct file_region *rg, *nrg, *trg;
79
80 /* Locate the region we are either in or before. */
81 list_for_each_entry(rg, head, link)
82 if (f <= rg->to)
83 break;
84
85 /* Round our left edge to the current segment if it encloses us. */
86 if (f > rg->from)
87 f = rg->from;
88
89 /* Check for and consume any regions we now overlap with. */
90 nrg = rg;
91 list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
92 if (&rg->link == head)
93 break;
94 if (rg->from > t)
95 break;
96
97 /* If this area reaches higher then extend our area to
98 * include it completely. If this is not the first area
99 * which we intend to reuse, free it. */
100 if (rg->to > t)
101 t = rg->to;
102 if (rg != nrg) {
103 list_del(&rg->link);
104 kfree(rg);
105 }
106 }
107 nrg->from = f;
108 nrg->to = t;
109 return 0;
110}
111
112static long region_chg(struct list_head *head, long f, long t)
113{
114 struct file_region *rg, *nrg;
115 long chg = 0;
116
117 /* Locate the region we are before or in. */
118 list_for_each_entry(rg, head, link)
119 if (f <= rg->to)
120 break;
121
122 /* If we are below the current region then a new region is required.
123 * Subtle, allocate a new region at the position but make it zero
124 * size such that we can guarantee to record the reservation. */
125 if (&rg->link == head || t < rg->from) {
126 nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
127 if (!nrg)
128 return -ENOMEM;
129 nrg->from = f;
130 nrg->to = f;
131 INIT_LIST_HEAD(&nrg->link);
132 list_add(&nrg->link, rg->link.prev);
133
134 return t - f;
135 }
136
137 /* Round our left edge to the current segment if it encloses us. */
138 if (f > rg->from)
139 f = rg->from;
140 chg = t - f;
141
142 /* Check for and consume any regions we now overlap with. */
143 list_for_each_entry(rg, rg->link.prev, link) {
144 if (&rg->link == head)
145 break;
146 if (rg->from > t)
147 return chg;
148
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300149 /* We overlap with this area, if it extends further than
Andy Whitcroft96822902008-07-23 21:27:29 -0700150 * us then we must extend ourselves. Account for its
151 * existing reservation. */
152 if (rg->to > t) {
153 chg += rg->to - t;
154 t = rg->to;
155 }
156 chg -= rg->to - rg->from;
157 }
158 return chg;
159}
160
161static long region_truncate(struct list_head *head, long end)
162{
163 struct file_region *rg, *trg;
164 long chg = 0;
165
166 /* Locate the region we are either in or before. */
167 list_for_each_entry(rg, head, link)
168 if (end <= rg->to)
169 break;
170 if (&rg->link == head)
171 return 0;
172
173 /* If we are in the middle of a region then adjust it. */
174 if (end > rg->from) {
175 chg = rg->to - end;
176 rg->to = end;
177 rg = list_entry(rg->link.next, typeof(*rg), link);
178 }
179
180 /* Drop any remaining regions. */
181 list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
182 if (&rg->link == head)
183 break;
184 chg += rg->to - rg->from;
185 list_del(&rg->link);
186 kfree(rg);
187 }
188 return chg;
189}
190
Andy Whitcroft84afd992008-07-23 21:27:32 -0700191static long region_count(struct list_head *head, long f, long t)
192{
193 struct file_region *rg;
194 long chg = 0;
195
196 /* Locate each segment we overlap with, and count that overlap. */
197 list_for_each_entry(rg, head, link) {
198 int seg_from;
199 int seg_to;
200
201 if (rg->to <= f)
202 continue;
203 if (rg->from >= t)
204 break;
205
206 seg_from = max(rg->from, f);
207 seg_to = min(rg->to, t);
208
209 chg += seg_to - seg_from;
210 }
211
212 return chg;
213}
214
Andy Whitcroft96822902008-07-23 21:27:29 -0700215/*
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700216 * Convert the address within this vma to the page offset within
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700217 * the mapping, in pagecache page units; huge pages here.
218 */
Andi Kleena5516432008-07-23 21:27:41 -0700219static pgoff_t vma_hugecache_offset(struct hstate *h,
220 struct vm_area_struct *vma, unsigned long address)
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700221{
Andi Kleena5516432008-07-23 21:27:41 -0700222 return ((address - vma->vm_start) >> huge_page_shift(h)) +
223 (vma->vm_pgoff >> huge_page_order(h));
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700224}
225
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +0900226pgoff_t linear_hugepage_index(struct vm_area_struct *vma,
227 unsigned long address)
228{
229 return vma_hugecache_offset(hstate_vma(vma), vma, address);
230}
231
Andy Whitcroft84afd992008-07-23 21:27:32 -0700232/*
Mel Gorman08fba692009-01-06 14:38:53 -0800233 * Return the size of the pages allocated when backing a VMA. In the majority
234 * cases this will be same size as used by the page table entries.
235 */
236unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
237{
238 struct hstate *hstate;
239
240 if (!is_vm_hugetlb_page(vma))
241 return PAGE_SIZE;
242
243 hstate = hstate_vma(vma);
244
245 return 1UL << (hstate->order + PAGE_SHIFT);
246}
Joerg Roedelf340ca02009-06-19 15:16:22 +0200247EXPORT_SYMBOL_GPL(vma_kernel_pagesize);
Mel Gorman08fba692009-01-06 14:38:53 -0800248
249/*
Mel Gorman33402892009-01-06 14:38:54 -0800250 * Return the page size being used by the MMU to back a VMA. In the majority
251 * of cases, the page size used by the kernel matches the MMU size. On
252 * architectures where it differs, an architecture-specific version of this
253 * function is required.
254 */
255#ifndef vma_mmu_pagesize
256unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
257{
258 return vma_kernel_pagesize(vma);
259}
260#endif
261
262/*
Andy Whitcroft84afd992008-07-23 21:27:32 -0700263 * Flags for MAP_PRIVATE reservations. These are stored in the bottom
264 * bits of the reservation map pointer, which are always clear due to
265 * alignment.
266 */
267#define HPAGE_RESV_OWNER (1UL << 0)
268#define HPAGE_RESV_UNMAPPED (1UL << 1)
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700269#define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED)
Andy Whitcroft84afd992008-07-23 21:27:32 -0700270
Mel Gormana1e78772008-07-23 21:27:23 -0700271/*
272 * These helpers are used to track how many pages are reserved for
273 * faults in a MAP_PRIVATE mapping. Only the process that called mmap()
274 * is guaranteed to have their future faults succeed.
275 *
276 * With the exception of reset_vma_resv_huge_pages() which is called at fork(),
277 * the reserve counters are updated with the hugetlb_lock held. It is safe
278 * to reset the VMA at fork() time as it is not in use yet and there is no
279 * chance of the global counters getting corrupted as a result of the values.
Andy Whitcroft84afd992008-07-23 21:27:32 -0700280 *
281 * The private mapping reservation is represented in a subtly different
282 * manner to a shared mapping. A shared mapping has a region map associated
283 * with the underlying file, this region map represents the backing file
284 * pages which have ever had a reservation assigned which this persists even
285 * after the page is instantiated. A private mapping has a region map
286 * associated with the original mmap which is attached to all VMAs which
287 * reference it, this region map represents those offsets which have consumed
288 * reservation ie. where pages have been instantiated.
Mel Gormana1e78772008-07-23 21:27:23 -0700289 */
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700290static unsigned long get_vma_private_data(struct vm_area_struct *vma)
291{
292 return (unsigned long)vma->vm_private_data;
293}
294
295static void set_vma_private_data(struct vm_area_struct *vma,
296 unsigned long value)
297{
298 vma->vm_private_data = (void *)value;
299}
300
Andy Whitcroft84afd992008-07-23 21:27:32 -0700301struct resv_map {
302 struct kref refs;
303 struct list_head regions;
304};
305
Harvey Harrison2a4b3de2008-10-18 20:27:06 -0700306static struct resv_map *resv_map_alloc(void)
Andy Whitcroft84afd992008-07-23 21:27:32 -0700307{
308 struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL);
309 if (!resv_map)
310 return NULL;
311
312 kref_init(&resv_map->refs);
313 INIT_LIST_HEAD(&resv_map->regions);
314
315 return resv_map;
316}
317
Harvey Harrison2a4b3de2008-10-18 20:27:06 -0700318static void resv_map_release(struct kref *ref)
Andy Whitcroft84afd992008-07-23 21:27:32 -0700319{
320 struct resv_map *resv_map = container_of(ref, struct resv_map, refs);
321
322 /* Clear out any active regions before we release the map. */
323 region_truncate(&resv_map->regions, 0);
324 kfree(resv_map);
325}
326
327static struct resv_map *vma_resv_map(struct vm_area_struct *vma)
Mel Gormana1e78772008-07-23 21:27:23 -0700328{
329 VM_BUG_ON(!is_vm_hugetlb_page(vma));
Mel Gormanf83a2752009-05-28 14:34:40 -0700330 if (!(vma->vm_flags & VM_MAYSHARE))
Andy Whitcroft84afd992008-07-23 21:27:32 -0700331 return (struct resv_map *)(get_vma_private_data(vma) &
332 ~HPAGE_RESV_MASK);
Harvey Harrison2a4b3de2008-10-18 20:27:06 -0700333 return NULL;
Mel Gormana1e78772008-07-23 21:27:23 -0700334}
335
Andy Whitcroft84afd992008-07-23 21:27:32 -0700336static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map)
Mel Gormana1e78772008-07-23 21:27:23 -0700337{
338 VM_BUG_ON(!is_vm_hugetlb_page(vma));
Mel Gormanf83a2752009-05-28 14:34:40 -0700339 VM_BUG_ON(vma->vm_flags & VM_MAYSHARE);
Mel Gormana1e78772008-07-23 21:27:23 -0700340
Andy Whitcroft84afd992008-07-23 21:27:32 -0700341 set_vma_private_data(vma, (get_vma_private_data(vma) &
342 HPAGE_RESV_MASK) | (unsigned long)map);
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700343}
344
345static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags)
346{
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700347 VM_BUG_ON(!is_vm_hugetlb_page(vma));
Mel Gormanf83a2752009-05-28 14:34:40 -0700348 VM_BUG_ON(vma->vm_flags & VM_MAYSHARE);
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700349
350 set_vma_private_data(vma, get_vma_private_data(vma) | flags);
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700351}
352
353static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag)
354{
355 VM_BUG_ON(!is_vm_hugetlb_page(vma));
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -0700356
357 return (get_vma_private_data(vma) & flag) != 0;
Mel Gormana1e78772008-07-23 21:27:23 -0700358}
359
360/* Decrement the reserved pages in the hugepage pool by one */
Andi Kleena5516432008-07-23 21:27:41 -0700361static void decrement_hugepage_resv_vma(struct hstate *h,
362 struct vm_area_struct *vma)
Mel Gormana1e78772008-07-23 21:27:23 -0700363{
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700364 if (vma->vm_flags & VM_NORESERVE)
365 return;
366
Mel Gormanf83a2752009-05-28 14:34:40 -0700367 if (vma->vm_flags & VM_MAYSHARE) {
Mel Gormana1e78772008-07-23 21:27:23 -0700368 /* Shared mappings always use reserves */
Andi Kleena5516432008-07-23 21:27:41 -0700369 h->resv_huge_pages--;
Andy Whitcroft84afd992008-07-23 21:27:32 -0700370 } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
Mel Gormana1e78772008-07-23 21:27:23 -0700371 /*
372 * Only the process that called mmap() has reserves for
373 * private mappings.
374 */
Andi Kleena5516432008-07-23 21:27:41 -0700375 h->resv_huge_pages--;
Mel Gormana1e78772008-07-23 21:27:23 -0700376 }
377}
378
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700379/* Reset counters to 0 and clear all HPAGE_RESV_* flags */
Mel Gormana1e78772008-07-23 21:27:23 -0700380void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
381{
382 VM_BUG_ON(!is_vm_hugetlb_page(vma));
Mel Gormanf83a2752009-05-28 14:34:40 -0700383 if (!(vma->vm_flags & VM_MAYSHARE))
Mel Gormana1e78772008-07-23 21:27:23 -0700384 vma->vm_private_data = (void *)0;
385}
386
387/* Returns true if the VMA has associated reserve pages */
Mel Gorman7f09ca52008-07-23 21:27:58 -0700388static int vma_has_reserves(struct vm_area_struct *vma)
Mel Gormana1e78772008-07-23 21:27:23 -0700389{
Mel Gormanf83a2752009-05-28 14:34:40 -0700390 if (vma->vm_flags & VM_MAYSHARE)
Mel Gorman7f09ca52008-07-23 21:27:58 -0700391 return 1;
392 if (is_vma_resv_set(vma, HPAGE_RESV_OWNER))
393 return 1;
394 return 0;
Mel Gormana1e78772008-07-23 21:27:23 -0700395}
396
Naoya Horiguchi0ebabb42010-09-08 10:19:34 +0900397static void copy_gigantic_page(struct page *dst, struct page *src)
398{
399 int i;
400 struct hstate *h = page_hstate(src);
401 struct page *dst_base = dst;
402 struct page *src_base = src;
403
404 for (i = 0; i < pages_per_huge_page(h); ) {
405 cond_resched();
406 copy_highpage(dst, src);
407
408 i++;
409 dst = mem_map_next(dst, dst_base, i);
410 src = mem_map_next(src, src_base, i);
411 }
412}
413
414void copy_huge_page(struct page *dst, struct page *src)
415{
416 int i;
417 struct hstate *h = page_hstate(src);
418
419 if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) {
420 copy_gigantic_page(dst, src);
421 return;
422 }
423
424 might_sleep();
425 for (i = 0; i < pages_per_huge_page(h); i++) {
426 cond_resched();
427 copy_highpage(dst + i, src + i);
428 }
429}
430
Andi Kleena5516432008-07-23 21:27:41 -0700431static void enqueue_huge_page(struct hstate *h, struct page *page)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432{
433 int nid = page_to_nid(page);
Andi Kleena5516432008-07-23 21:27:41 -0700434 list_add(&page->lru, &h->hugepage_freelists[nid]);
435 h->free_huge_pages++;
436 h->free_huge_pages_node[nid]++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437}
438
Naoya Horiguchibf50bab2010-09-08 10:19:33 +0900439static struct page *dequeue_huge_page_node(struct hstate *h, int nid)
440{
441 struct page *page;
442
443 if (list_empty(&h->hugepage_freelists[nid]))
444 return NULL;
445 page = list_entry(h->hugepage_freelists[nid].next, struct page, lru);
446 list_del(&page->lru);
Naoya Horiguchia9869b82010-09-08 10:19:37 +0900447 set_page_refcounted(page);
Naoya Horiguchibf50bab2010-09-08 10:19:33 +0900448 h->free_huge_pages--;
449 h->free_huge_pages_node[nid]--;
450 return page;
451}
452
Andi Kleena5516432008-07-23 21:27:41 -0700453static struct page *dequeue_huge_page_vma(struct hstate *h,
454 struct vm_area_struct *vma,
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700455 unsigned long address, int avoid_reserve)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 struct page *page = NULL;
Lee Schermerhorn480eccf2007-09-18 22:46:47 -0700458 struct mempolicy *mpol;
Mel Gorman19770b32008-04-28 02:12:18 -0700459 nodemask_t *nodemask;
Miao Xiec0ff7452010-05-24 14:32:08 -0700460 struct zonelist *zonelist;
Mel Gormandd1a2392008-04-28 02:12:17 -0700461 struct zone *zone;
462 struct zoneref *z;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463
Miao Xiec0ff7452010-05-24 14:32:08 -0700464 get_mems_allowed();
465 zonelist = huge_zonelist(vma, address,
466 htlb_alloc_mask, &mpol, &nodemask);
Mel Gormana1e78772008-07-23 21:27:23 -0700467 /*
468 * A child process with MAP_PRIVATE mappings created by their parent
469 * have no page reserves. This check ensures that reservations are
470 * not "stolen". The child may still get SIGKILLed
471 */
Mel Gorman7f09ca52008-07-23 21:27:58 -0700472 if (!vma_has_reserves(vma) &&
Andi Kleena5516432008-07-23 21:27:41 -0700473 h->free_huge_pages - h->resv_huge_pages == 0)
Miao Xiec0ff7452010-05-24 14:32:08 -0700474 goto err;
Mel Gormana1e78772008-07-23 21:27:23 -0700475
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700476 /* If reserves cannot be used, ensure enough pages are in the pool */
Andi Kleena5516432008-07-23 21:27:41 -0700477 if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0)
Justin P. Mattock6eab04a2011-04-08 19:49:08 -0700478 goto err;
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700479
Mel Gorman19770b32008-04-28 02:12:18 -0700480 for_each_zone_zonelist_nodemask(zone, z, zonelist,
481 MAX_NR_ZONES - 1, nodemask) {
Naoya Horiguchibf50bab2010-09-08 10:19:33 +0900482 if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask)) {
483 page = dequeue_huge_page_node(h, zone_to_nid(zone));
484 if (page) {
485 if (!avoid_reserve)
486 decrement_hugepage_resv_vma(h, vma);
487 break;
488 }
Andrew Morton3abf7af2007-07-19 01:49:08 -0700489 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 }
Miao Xiec0ff7452010-05-24 14:32:08 -0700491err:
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700492 mpol_cond_put(mpol);
Miao Xiec0ff7452010-05-24 14:32:08 -0700493 put_mems_allowed();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 return page;
495}
496
Andi Kleena5516432008-07-23 21:27:41 -0700497static void update_and_free_page(struct hstate *h, struct page *page)
Adam Litke6af2acb2007-10-16 01:26:16 -0700498{
499 int i;
Andi Kleena5516432008-07-23 21:27:41 -0700500
Andy Whitcroft18229df2008-11-06 12:53:27 -0800501 VM_BUG_ON(h->order >= MAX_ORDER);
502
Andi Kleena5516432008-07-23 21:27:41 -0700503 h->nr_huge_pages--;
504 h->nr_huge_pages_node[page_to_nid(page)]--;
505 for (i = 0; i < pages_per_huge_page(h); i++) {
Chris Forbes32f84522011-07-25 17:12:14 -0700506 page[i].flags &= ~(1 << PG_locked | 1 << PG_error |
507 1 << PG_referenced | 1 << PG_dirty |
508 1 << PG_active | 1 << PG_reserved |
509 1 << PG_private | 1 << PG_writeback);
Adam Litke6af2acb2007-10-16 01:26:16 -0700510 }
511 set_compound_page_dtor(page, NULL);
512 set_page_refcounted(page);
Gerald Schaefer7f2e9522008-04-28 02:13:29 -0700513 arch_release_hugepage(page);
Andi Kleena5516432008-07-23 21:27:41 -0700514 __free_pages(page, huge_page_order(h));
Adam Litke6af2acb2007-10-16 01:26:16 -0700515}
516
Andi Kleene5ff2152008-07-23 21:27:42 -0700517struct hstate *size_to_hstate(unsigned long size)
518{
519 struct hstate *h;
520
521 for_each_hstate(h) {
522 if (huge_page_size(h) == size)
523 return h;
524 }
525 return NULL;
526}
527
David Gibson27a85ef2006-03-22 00:08:56 -0800528static void free_huge_page(struct page *page)
529{
Andi Kleena5516432008-07-23 21:27:41 -0700530 /*
531 * Can't pass hstate in here because it is called from the
532 * compound page destructor.
533 */
Andi Kleene5ff2152008-07-23 21:27:42 -0700534 struct hstate *h = page_hstate(page);
Adam Litke7893d1d2007-10-16 01:26:18 -0700535 int nid = page_to_nid(page);
Adam Litkec79fb752007-11-14 16:59:38 -0800536 struct address_space *mapping;
David Gibson27a85ef2006-03-22 00:08:56 -0800537
Adam Litkec79fb752007-11-14 16:59:38 -0800538 mapping = (struct address_space *) page_private(page);
Andy Whitcrofte5df70a2008-02-23 15:23:32 -0800539 set_page_private(page, 0);
Mel Gorman23be7462010-04-23 13:17:56 -0400540 page->mapping = NULL;
Adam Litke7893d1d2007-10-16 01:26:18 -0700541 BUG_ON(page_count(page));
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +0900542 BUG_ON(page_mapcount(page));
David Gibson27a85ef2006-03-22 00:08:56 -0800543 INIT_LIST_HEAD(&page->lru);
544
545 spin_lock(&hugetlb_lock);
Andi Kleenaa888a72008-07-23 21:27:47 -0700546 if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) {
Andi Kleena5516432008-07-23 21:27:41 -0700547 update_and_free_page(h, page);
548 h->surplus_huge_pages--;
549 h->surplus_huge_pages_node[nid]--;
Adam Litke7893d1d2007-10-16 01:26:18 -0700550 } else {
Andi Kleena5516432008-07-23 21:27:41 -0700551 enqueue_huge_page(h, page);
Adam Litke7893d1d2007-10-16 01:26:18 -0700552 }
David Gibson27a85ef2006-03-22 00:08:56 -0800553 spin_unlock(&hugetlb_lock);
Adam Litkec79fb752007-11-14 16:59:38 -0800554 if (mapping)
Adam Litke9a119c02007-11-14 16:59:41 -0800555 hugetlb_put_quota(mapping, 1);
David Gibson27a85ef2006-03-22 00:08:56 -0800556}
557
Andi Kleena5516432008-07-23 21:27:41 -0700558static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
Andi Kleenb7ba30c2008-07-23 21:27:40 -0700559{
560 set_compound_page_dtor(page, free_huge_page);
561 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -0700562 h->nr_huge_pages++;
563 h->nr_huge_pages_node[nid]++;
Andi Kleenb7ba30c2008-07-23 21:27:40 -0700564 spin_unlock(&hugetlb_lock);
565 put_page(page); /* free it into the hugepage allocator */
566}
567
Wu Fengguang20a03072009-06-16 15:32:22 -0700568static void prep_compound_gigantic_page(struct page *page, unsigned long order)
569{
570 int i;
571 int nr_pages = 1 << order;
572 struct page *p = page + 1;
573
574 /* we rely on prep_new_huge_page to set the destructor */
575 set_compound_order(page, order);
576 __SetPageHead(page);
577 for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
578 __SetPageTail(p);
579 p->first_page = page;
580 }
581}
582
583int PageHuge(struct page *page)
584{
585 compound_page_dtor *dtor;
586
587 if (!PageCompound(page))
588 return 0;
589
590 page = compound_head(page);
591 dtor = get_compound_page_dtor(page);
592
593 return dtor == free_huge_page;
594}
Naoya Horiguchi43131e12010-05-28 09:29:22 +0900595EXPORT_SYMBOL_GPL(PageHuge);
596
Andi Kleena5516432008-07-23 21:27:41 -0700597static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 struct page *page;
Joe Jinf96efd52007-07-15 23:38:12 -0700600
Andi Kleenaa888a72008-07-23 21:27:47 -0700601 if (h->order >= MAX_ORDER)
602 return NULL;
603
Mel Gorman6484eb32009-06-16 15:31:54 -0700604 page = alloc_pages_exact_node(nid,
Nishanth Aravamudan551883a2008-04-29 00:58:26 -0700605 htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
606 __GFP_REPEAT|__GFP_NOWARN,
Andi Kleena5516432008-07-23 21:27:41 -0700607 huge_page_order(h));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608 if (page) {
Gerald Schaefer7f2e9522008-04-28 02:13:29 -0700609 if (arch_prepare_hugepage(page)) {
Gerald Schaefercaff3a22008-08-12 15:08:38 -0700610 __free_pages(page, huge_page_order(h));
Harvey Harrison7b8ee842008-04-28 14:13:19 -0700611 return NULL;
Gerald Schaefer7f2e9522008-04-28 02:13:29 -0700612 }
Andi Kleena5516432008-07-23 21:27:41 -0700613 prep_new_huge_page(h, page, nid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 }
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700615
616 return page;
617}
618
Andi Kleen5ced66c2008-07-23 21:27:45 -0700619/*
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800620 * common helper functions for hstate_next_node_to_{alloc|free}.
621 * We may have allocated or freed a huge page based on a different
622 * nodes_allowed previously, so h->next_node_to_{alloc|free} might
623 * be outside of *nodes_allowed. Ensure that we use an allowed
624 * node for alloc or free.
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800625 */
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800626static int next_node_allowed(int nid, nodemask_t *nodes_allowed)
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800627{
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800628 nid = next_node(nid, *nodes_allowed);
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800629 if (nid == MAX_NUMNODES)
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800630 nid = first_node(*nodes_allowed);
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800631 VM_BUG_ON(nid >= MAX_NUMNODES);
632
633 return nid;
634}
635
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800636static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed)
Andi Kleen5ced66c2008-07-23 21:27:45 -0700637{
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800638 if (!node_isset(nid, *nodes_allowed))
639 nid = next_node_allowed(nid, nodes_allowed);
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800640 return nid;
Andi Kleen5ced66c2008-07-23 21:27:45 -0700641}
642
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800643/*
644 * returns the previously saved node ["this node"] from which to
645 * allocate a persistent huge page for the pool and advance the
646 * next node from which to allocate, handling wrap at end of node
647 * mask.
648 */
649static int hstate_next_node_to_alloc(struct hstate *h,
650 nodemask_t *nodes_allowed)
651{
652 int nid;
653
654 VM_BUG_ON(!nodes_allowed);
655
656 nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed);
657 h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed);
658
659 return nid;
660}
661
662static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed)
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700663{
664 struct page *page;
665 int start_nid;
666 int next_nid;
667 int ret = 0;
668
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800669 start_nid = hstate_next_node_to_alloc(h, nodes_allowed);
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700670 next_nid = start_nid;
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700671
672 do {
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700673 page = alloc_fresh_huge_page_node(h, next_nid);
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800674 if (page) {
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700675 ret = 1;
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800676 break;
677 }
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800678 next_nid = hstate_next_node_to_alloc(h, nodes_allowed);
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800679 } while (next_nid != start_nid);
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700680
Adam Litke3b116302008-04-28 02:13:06 -0700681 if (ret)
682 count_vm_event(HTLB_BUDDY_PGALLOC);
683 else
684 count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
685
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700686 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687}
688
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700689/*
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800690 * helper for free_pool_huge_page() - return the previously saved
691 * node ["this node"] from which to free a huge page. Advance the
692 * next node id whether or not we find a free huge page to free so
693 * that the next attempt to free addresses the next node.
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700694 */
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800695static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed)
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700696{
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800697 int nid;
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800698
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800699 VM_BUG_ON(!nodes_allowed);
700
701 nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed);
702 h->next_nid_to_free = next_node_allowed(nid, nodes_allowed);
703
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800704 return nid;
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700705}
706
707/*
708 * Free huge page from pool from next node to free.
709 * Attempt to keep persistent huge pages more or less
710 * balanced over allowed nodes.
711 * Called with hugetlb_lock locked.
712 */
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800713static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed,
714 bool acct_surplus)
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700715{
716 int start_nid;
717 int next_nid;
718 int ret = 0;
719
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800720 start_nid = hstate_next_node_to_free(h, nodes_allowed);
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700721 next_nid = start_nid;
722
723 do {
Lee Schermerhorn685f3452009-09-21 17:01:23 -0700724 /*
725 * If we're returning unused surplus pages, only examine
726 * nodes with surplus pages.
727 */
728 if ((!acct_surplus || h->surplus_huge_pages_node[next_nid]) &&
729 !list_empty(&h->hugepage_freelists[next_nid])) {
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700730 struct page *page =
731 list_entry(h->hugepage_freelists[next_nid].next,
732 struct page, lru);
733 list_del(&page->lru);
734 h->free_huge_pages--;
735 h->free_huge_pages_node[next_nid]--;
Lee Schermerhorn685f3452009-09-21 17:01:23 -0700736 if (acct_surplus) {
737 h->surplus_huge_pages--;
738 h->surplus_huge_pages_node[next_nid]--;
739 }
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700740 update_and_free_page(h, page);
741 ret = 1;
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800742 break;
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700743 }
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800744 next_nid = hstate_next_node_to_free(h, nodes_allowed);
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800745 } while (next_nid != start_nid);
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700746
747 return ret;
748}
749
Naoya Horiguchibf50bab2010-09-08 10:19:33 +0900750static struct page *alloc_buddy_huge_page(struct hstate *h, int nid)
Adam Litke7893d1d2007-10-16 01:26:18 -0700751{
752 struct page *page;
Naoya Horiguchibf50bab2010-09-08 10:19:33 +0900753 unsigned int r_nid;
Adam Litke7893d1d2007-10-16 01:26:18 -0700754
Andi Kleenaa888a72008-07-23 21:27:47 -0700755 if (h->order >= MAX_ORDER)
756 return NULL;
757
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800758 /*
759 * Assume we will successfully allocate the surplus page to
760 * prevent racing processes from causing the surplus to exceed
761 * overcommit
762 *
763 * This however introduces a different race, where a process B
764 * tries to grow the static hugepage pool while alloc_pages() is
765 * called by process A. B will only examine the per-node
766 * counters in determining if surplus huge pages can be
767 * converted to normal huge pages in adjust_pool_surplus(). A
768 * won't be able to increment the per-node counter, until the
769 * lock is dropped by B, but B doesn't drop hugetlb_lock until
770 * no more huge pages can be converted from surplus to normal
771 * state (and doesn't try to convert again). Thus, we have a
772 * case where a surplus huge page exists, the pool is grown, and
773 * the surplus huge page still exists after, even though it
774 * should just have been converted to a normal huge page. This
775 * does not leak memory, though, as the hugepage will be freed
776 * once it is out of use. It also does not allow the counters to
777 * go out of whack in adjust_pool_surplus() as we don't modify
778 * the node values until we've gotten the hugepage and only the
779 * per-node value is checked there.
780 */
781 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -0700782 if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) {
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800783 spin_unlock(&hugetlb_lock);
784 return NULL;
785 } else {
Andi Kleena5516432008-07-23 21:27:41 -0700786 h->nr_huge_pages++;
787 h->surplus_huge_pages++;
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800788 }
789 spin_unlock(&hugetlb_lock);
790
Naoya Horiguchibf50bab2010-09-08 10:19:33 +0900791 if (nid == NUMA_NO_NODE)
792 page = alloc_pages(htlb_alloc_mask|__GFP_COMP|
793 __GFP_REPEAT|__GFP_NOWARN,
794 huge_page_order(h));
795 else
796 page = alloc_pages_exact_node(nid,
797 htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
798 __GFP_REPEAT|__GFP_NOWARN, huge_page_order(h));
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800799
Gerald Schaefercaff3a22008-08-12 15:08:38 -0700800 if (page && arch_prepare_hugepage(page)) {
801 __free_pages(page, huge_page_order(h));
802 return NULL;
803 }
804
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800805 spin_lock(&hugetlb_lock);
Adam Litke7893d1d2007-10-16 01:26:18 -0700806 if (page) {
Naoya Horiguchibf50bab2010-09-08 10:19:33 +0900807 r_nid = page_to_nid(page);
Adam Litke7893d1d2007-10-16 01:26:18 -0700808 set_compound_page_dtor(page, free_huge_page);
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800809 /*
810 * We incremented the global counters already
811 */
Naoya Horiguchibf50bab2010-09-08 10:19:33 +0900812 h->nr_huge_pages_node[r_nid]++;
813 h->surplus_huge_pages_node[r_nid]++;
Adam Litke3b116302008-04-28 02:13:06 -0700814 __count_vm_event(HTLB_BUDDY_PGALLOC);
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800815 } else {
Andi Kleena5516432008-07-23 21:27:41 -0700816 h->nr_huge_pages--;
817 h->surplus_huge_pages--;
Adam Litke3b116302008-04-28 02:13:06 -0700818 __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
Adam Litke7893d1d2007-10-16 01:26:18 -0700819 }
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800820 spin_unlock(&hugetlb_lock);
Adam Litke7893d1d2007-10-16 01:26:18 -0700821
822 return page;
823}
824
Adam Litkee4e574b2007-10-16 01:26:19 -0700825/*
Naoya Horiguchibf50bab2010-09-08 10:19:33 +0900826 * This allocation function is useful in the context where vma is irrelevant.
827 * E.g. soft-offlining uses this function because it only cares physical
828 * address of error page.
829 */
830struct page *alloc_huge_page_node(struct hstate *h, int nid)
831{
832 struct page *page;
833
834 spin_lock(&hugetlb_lock);
835 page = dequeue_huge_page_node(h, nid);
836 spin_unlock(&hugetlb_lock);
837
838 if (!page)
839 page = alloc_buddy_huge_page(h, nid);
840
841 return page;
842}
843
844/*
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300845 * Increase the hugetlb pool such that it can accommodate a reservation
Adam Litkee4e574b2007-10-16 01:26:19 -0700846 * of size 'delta'.
847 */
Andi Kleena5516432008-07-23 21:27:41 -0700848static int gather_surplus_pages(struct hstate *h, int delta)
Adam Litkee4e574b2007-10-16 01:26:19 -0700849{
850 struct list_head surplus_list;
851 struct page *page, *tmp;
852 int ret, i;
853 int needed, allocated;
854
Andi Kleena5516432008-07-23 21:27:41 -0700855 needed = (h->resv_huge_pages + delta) - h->free_huge_pages;
Adam Litkeac09b3a2008-03-04 14:29:38 -0800856 if (needed <= 0) {
Andi Kleena5516432008-07-23 21:27:41 -0700857 h->resv_huge_pages += delta;
Adam Litkee4e574b2007-10-16 01:26:19 -0700858 return 0;
Adam Litkeac09b3a2008-03-04 14:29:38 -0800859 }
Adam Litkee4e574b2007-10-16 01:26:19 -0700860
861 allocated = 0;
862 INIT_LIST_HEAD(&surplus_list);
863
864 ret = -ENOMEM;
865retry:
866 spin_unlock(&hugetlb_lock);
867 for (i = 0; i < needed; i++) {
Naoya Horiguchibf50bab2010-09-08 10:19:33 +0900868 page = alloc_buddy_huge_page(h, NUMA_NO_NODE);
Naoya Horiguchia9869b82010-09-08 10:19:37 +0900869 if (!page)
Adam Litkee4e574b2007-10-16 01:26:19 -0700870 /*
871 * We were not able to allocate enough pages to
872 * satisfy the entire reservation so we free what
873 * we've allocated so far.
874 */
Adam Litkee4e574b2007-10-16 01:26:19 -0700875 goto free;
Adam Litkee4e574b2007-10-16 01:26:19 -0700876
877 list_add(&page->lru, &surplus_list);
878 }
879 allocated += needed;
880
881 /*
882 * After retaking hugetlb_lock, we need to recalculate 'needed'
883 * because either resv_huge_pages or free_huge_pages may have changed.
884 */
885 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -0700886 needed = (h->resv_huge_pages + delta) -
887 (h->free_huge_pages + allocated);
Adam Litkee4e574b2007-10-16 01:26:19 -0700888 if (needed > 0)
889 goto retry;
890
891 /*
892 * The surplus_list now contains _at_least_ the number of extra pages
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300893 * needed to accommodate the reservation. Add the appropriate number
Adam Litkee4e574b2007-10-16 01:26:19 -0700894 * of pages to the hugetlb pool and free the extras back to the buddy
Adam Litkeac09b3a2008-03-04 14:29:38 -0800895 * allocator. Commit the entire reservation here to prevent another
896 * process from stealing the pages as they are added to the pool but
897 * before they are reserved.
Adam Litkee4e574b2007-10-16 01:26:19 -0700898 */
899 needed += allocated;
Andi Kleena5516432008-07-23 21:27:41 -0700900 h->resv_huge_pages += delta;
Adam Litkee4e574b2007-10-16 01:26:19 -0700901 ret = 0;
Naoya Horiguchia9869b82010-09-08 10:19:37 +0900902
903 spin_unlock(&hugetlb_lock);
Adam Litke19fc3f02008-04-28 02:12:20 -0700904 /* Free the needed pages to the hugetlb pool */
Adam Litkee4e574b2007-10-16 01:26:19 -0700905 list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
Adam Litke19fc3f02008-04-28 02:12:20 -0700906 if ((--needed) < 0)
907 break;
Adam Litkee4e574b2007-10-16 01:26:19 -0700908 list_del(&page->lru);
Naoya Horiguchia9869b82010-09-08 10:19:37 +0900909 /*
910 * This page is now managed by the hugetlb allocator and has
911 * no users -- drop the buddy allocator's reference.
912 */
913 put_page_testzero(page);
914 VM_BUG_ON(page_count(page));
Andi Kleena5516432008-07-23 21:27:41 -0700915 enqueue_huge_page(h, page);
Adam Litke19fc3f02008-04-28 02:12:20 -0700916 }
917
918 /* Free unnecessary surplus pages to the buddy allocator */
Naoya Horiguchia9869b82010-09-08 10:19:37 +0900919free:
Adam Litke19fc3f02008-04-28 02:12:20 -0700920 if (!list_empty(&surplus_list)) {
Adam Litke19fc3f02008-04-28 02:12:20 -0700921 list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
922 list_del(&page->lru);
Naoya Horiguchia9869b82010-09-08 10:19:37 +0900923 put_page(page);
Adam Litkeaf767cb2007-10-16 01:26:25 -0700924 }
Adam Litkee4e574b2007-10-16 01:26:19 -0700925 }
Naoya Horiguchia9869b82010-09-08 10:19:37 +0900926 spin_lock(&hugetlb_lock);
Adam Litkee4e574b2007-10-16 01:26:19 -0700927
928 return ret;
929}
930
931/*
932 * When releasing a hugetlb pool reservation, any surplus pages that were
933 * allocated to satisfy the reservation must be explicitly freed if they were
934 * never used.
Lee Schermerhorn685f3452009-09-21 17:01:23 -0700935 * Called with hugetlb_lock held.
Adam Litkee4e574b2007-10-16 01:26:19 -0700936 */
Andi Kleena5516432008-07-23 21:27:41 -0700937static void return_unused_surplus_pages(struct hstate *h,
938 unsigned long unused_resv_pages)
Adam Litkee4e574b2007-10-16 01:26:19 -0700939{
Adam Litkee4e574b2007-10-16 01:26:19 -0700940 unsigned long nr_pages;
941
Adam Litkeac09b3a2008-03-04 14:29:38 -0800942 /* Uncommit the reservation */
Andi Kleena5516432008-07-23 21:27:41 -0700943 h->resv_huge_pages -= unused_resv_pages;
Adam Litkeac09b3a2008-03-04 14:29:38 -0800944
Andi Kleenaa888a72008-07-23 21:27:47 -0700945 /* Cannot return gigantic pages currently */
946 if (h->order >= MAX_ORDER)
947 return;
948
Andi Kleena5516432008-07-23 21:27:41 -0700949 nr_pages = min(unused_resv_pages, h->surplus_huge_pages);
Adam Litkee4e574b2007-10-16 01:26:19 -0700950
Lee Schermerhorn685f3452009-09-21 17:01:23 -0700951 /*
952 * We want to release as many surplus pages as possible, spread
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -0800953 * evenly across all nodes with memory. Iterate across these nodes
954 * until we can no longer free unreserved surplus pages. This occurs
955 * when the nodes with surplus pages have no free pages.
956 * free_pool_huge_page() will balance the the freed pages across the
957 * on-line nodes with memory and will handle the hstate accounting.
Lee Schermerhorn685f3452009-09-21 17:01:23 -0700958 */
959 while (nr_pages--) {
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -0800960 if (!free_pool_huge_page(h, &node_states[N_HIGH_MEMORY], 1))
Lee Schermerhorn685f3452009-09-21 17:01:23 -0700961 break;
Adam Litkee4e574b2007-10-16 01:26:19 -0700962 }
963}
964
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700965/*
966 * Determine if the huge page at addr within the vma has an associated
967 * reservation. Where it does not we will need to logically increase
968 * reservation and actually increase quota before an allocation can occur.
969 * Where any new reservation would be required the reservation change is
970 * prepared, but not committed. Once the page has been quota'd allocated
971 * an instantiated the change should be committed via vma_commit_reservation.
972 * No action is required on failure.
973 */
Roel Kluine2f17d92009-03-31 15:23:15 -0700974static long vma_needs_reservation(struct hstate *h,
Andi Kleena5516432008-07-23 21:27:41 -0700975 struct vm_area_struct *vma, unsigned long addr)
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700976{
977 struct address_space *mapping = vma->vm_file->f_mapping;
978 struct inode *inode = mapping->host;
979
Mel Gormanf83a2752009-05-28 14:34:40 -0700980 if (vma->vm_flags & VM_MAYSHARE) {
Andi Kleena5516432008-07-23 21:27:41 -0700981 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700982 return region_chg(&inode->i_mapping->private_list,
983 idx, idx + 1);
984
Andy Whitcroft84afd992008-07-23 21:27:32 -0700985 } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
986 return 1;
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700987
Andy Whitcroft84afd992008-07-23 21:27:32 -0700988 } else {
Roel Kluine2f17d92009-03-31 15:23:15 -0700989 long err;
Andi Kleena5516432008-07-23 21:27:41 -0700990 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
Andy Whitcroft84afd992008-07-23 21:27:32 -0700991 struct resv_map *reservations = vma_resv_map(vma);
992
993 err = region_chg(&reservations->regions, idx, idx + 1);
994 if (err < 0)
995 return err;
996 return 0;
997 }
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700998}
Andi Kleena5516432008-07-23 21:27:41 -0700999static void vma_commit_reservation(struct hstate *h,
1000 struct vm_area_struct *vma, unsigned long addr)
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -07001001{
1002 struct address_space *mapping = vma->vm_file->f_mapping;
1003 struct inode *inode = mapping->host;
1004
Mel Gormanf83a2752009-05-28 14:34:40 -07001005 if (vma->vm_flags & VM_MAYSHARE) {
Andi Kleena5516432008-07-23 21:27:41 -07001006 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -07001007 region_add(&inode->i_mapping->private_list, idx, idx + 1);
Andy Whitcroft84afd992008-07-23 21:27:32 -07001008
1009 } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
Andi Kleena5516432008-07-23 21:27:41 -07001010 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
Andy Whitcroft84afd992008-07-23 21:27:32 -07001011 struct resv_map *reservations = vma_resv_map(vma);
1012
1013 /* Mark this page used in the map. */
1014 region_add(&reservations->regions, idx, idx + 1);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -07001015 }
1016}
1017
David Gibson27a85ef2006-03-22 00:08:56 -08001018static struct page *alloc_huge_page(struct vm_area_struct *vma,
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001019 unsigned long addr, int avoid_reserve)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020{
Andi Kleena5516432008-07-23 21:27:41 -07001021 struct hstate *h = hstate_vma(vma);
Adam Litke348ea202007-11-14 16:59:37 -08001022 struct page *page;
Adam Litke2fc39ce2007-11-14 16:59:39 -08001023 struct address_space *mapping = vma->vm_file->f_mapping;
Mel Gormana1e78772008-07-23 21:27:23 -07001024 struct inode *inode = mapping->host;
Roel Kluine2f17d92009-03-31 15:23:15 -07001025 long chg;
Adam Litke2fc39ce2007-11-14 16:59:39 -08001026
Mel Gormana1e78772008-07-23 21:27:23 -07001027 /*
1028 * Processes that did not create the mapping will have no reserves and
1029 * will not have accounted against quota. Check that the quota can be
1030 * made before satisfying the allocation
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -07001031 * MAP_NORESERVE mappings may also need pages and quota allocated
1032 * if no reserve mapping overlaps.
Mel Gormana1e78772008-07-23 21:27:23 -07001033 */
Andi Kleena5516432008-07-23 21:27:41 -07001034 chg = vma_needs_reservation(h, vma, addr);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -07001035 if (chg < 0)
Hugh Dickinse0dcd8a2011-06-05 22:03:13 -07001036 return ERR_PTR(-VM_FAULT_OOM);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -07001037 if (chg)
Mel Gormana1e78772008-07-23 21:27:23 -07001038 if (hugetlb_get_quota(inode->i_mapping, chg))
Hugh Dickinse0dcd8a2011-06-05 22:03:13 -07001039 return ERR_PTR(-VM_FAULT_SIGBUS);
Mel Gormana1e78772008-07-23 21:27:23 -07001040
1041 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -07001042 page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve);
Mel Gormana1e78772008-07-23 21:27:23 -07001043 spin_unlock(&hugetlb_lock);
1044
1045 if (!page) {
Naoya Horiguchibf50bab2010-09-08 10:19:33 +09001046 page = alloc_buddy_huge_page(h, NUMA_NO_NODE);
Mel Gormana1e78772008-07-23 21:27:23 -07001047 if (!page) {
1048 hugetlb_put_quota(inode->i_mapping, chg);
Mel Gorman4a6018f2010-05-11 14:06:53 -07001049 return ERR_PTR(-VM_FAULT_SIGBUS);
Mel Gormana1e78772008-07-23 21:27:23 -07001050 }
1051 }
1052
Mel Gormana1e78772008-07-23 21:27:23 -07001053 set_page_private(page, (unsigned long) mapping);
1054
Andi Kleena5516432008-07-23 21:27:41 -07001055 vma_commit_reservation(h, vma, addr);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -07001056
Adam Litke90d8b7e2007-11-14 16:59:42 -08001057 return page;
David Gibsonb45b5bd2006-03-22 00:08:55 -08001058}
1059
Cyrill Gorcunov91f47662009-01-06 14:40:33 -08001060int __weak alloc_bootmem_huge_page(struct hstate *h)
Andi Kleenaa888a72008-07-23 21:27:47 -07001061{
1062 struct huge_bootmem_page *m;
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -08001063 int nr_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
Andi Kleenaa888a72008-07-23 21:27:47 -07001064
1065 while (nr_nodes) {
1066 void *addr;
1067
1068 addr = __alloc_bootmem_node_nopanic(
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001069 NODE_DATA(hstate_next_node_to_alloc(h,
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -08001070 &node_states[N_HIGH_MEMORY])),
Andi Kleenaa888a72008-07-23 21:27:47 -07001071 huge_page_size(h), huge_page_size(h), 0);
1072
1073 if (addr) {
1074 /*
1075 * Use the beginning of the huge page to store the
1076 * huge_bootmem_page struct (until gather_bootmem
1077 * puts them into the mem_map).
1078 */
1079 m = addr;
Cyrill Gorcunov91f47662009-01-06 14:40:33 -08001080 goto found;
Andi Kleenaa888a72008-07-23 21:27:47 -07001081 }
Andi Kleenaa888a72008-07-23 21:27:47 -07001082 nr_nodes--;
1083 }
1084 return 0;
1085
1086found:
1087 BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1));
1088 /* Put them into a private list first because mem_map is not up yet */
1089 list_add(&m->list, &huge_boot_pages);
1090 m->hstate = h;
1091 return 1;
1092}
1093
Andy Whitcroft18229df2008-11-06 12:53:27 -08001094static void prep_compound_huge_page(struct page *page, int order)
1095{
1096 if (unlikely(order > (MAX_ORDER - 1)))
1097 prep_compound_gigantic_page(page, order);
1098 else
1099 prep_compound_page(page, order);
1100}
1101
Andi Kleenaa888a72008-07-23 21:27:47 -07001102/* Put bootmem huge pages into the standard lists after mem_map is up */
1103static void __init gather_bootmem_prealloc(void)
1104{
1105 struct huge_bootmem_page *m;
1106
1107 list_for_each_entry(m, &huge_boot_pages, list) {
Andi Kleenaa888a72008-07-23 21:27:47 -07001108 struct hstate *h = m->hstate;
Becky Bruceee8f2482011-07-25 17:11:50 -07001109 struct page *page;
1110
1111#ifdef CONFIG_HIGHMEM
1112 page = pfn_to_page(m->phys >> PAGE_SHIFT);
1113 free_bootmem_late((unsigned long)m,
1114 sizeof(struct huge_bootmem_page));
1115#else
1116 page = virt_to_page(m);
1117#endif
Andi Kleenaa888a72008-07-23 21:27:47 -07001118 __ClearPageReserved(page);
1119 WARN_ON(page_count(page) != 1);
Andy Whitcroft18229df2008-11-06 12:53:27 -08001120 prep_compound_huge_page(page, h->order);
Andi Kleenaa888a72008-07-23 21:27:47 -07001121 prep_new_huge_page(h, page, page_to_nid(page));
Rafael Aquinib0320c72011-06-15 15:08:39 -07001122 /*
1123 * If we had gigantic hugepages allocated at boot time, we need
1124 * to restore the 'stolen' pages to totalram_pages in order to
1125 * fix confusing memory reports from free(1) and another
1126 * side-effects, like CommitLimit going negative.
1127 */
1128 if (h->order > (MAX_ORDER - 1))
1129 totalram_pages += 1 << h->order;
Andi Kleenaa888a72008-07-23 21:27:47 -07001130 }
1131}
1132
Andi Kleen8faa8b02008-07-23 21:27:48 -07001133static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134{
1135 unsigned long i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136
Andi Kleene5ff2152008-07-23 21:27:42 -07001137 for (i = 0; i < h->max_huge_pages; ++i) {
Andi Kleenaa888a72008-07-23 21:27:47 -07001138 if (h->order >= MAX_ORDER) {
1139 if (!alloc_bootmem_huge_page(h))
1140 break;
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -08001141 } else if (!alloc_fresh_huge_page(h,
1142 &node_states[N_HIGH_MEMORY]))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144 }
Andi Kleen8faa8b02008-07-23 21:27:48 -07001145 h->max_huge_pages = i;
Andi Kleene5ff2152008-07-23 21:27:42 -07001146}
1147
1148static void __init hugetlb_init_hstates(void)
1149{
1150 struct hstate *h;
1151
1152 for_each_hstate(h) {
Andi Kleen8faa8b02008-07-23 21:27:48 -07001153 /* oversize hugepages were init'ed in early boot */
1154 if (h->order < MAX_ORDER)
1155 hugetlb_hstate_alloc_pages(h);
Andi Kleene5ff2152008-07-23 21:27:42 -07001156 }
1157}
1158
Andi Kleen4abd32d2008-07-23 21:27:49 -07001159static char * __init memfmt(char *buf, unsigned long n)
1160{
1161 if (n >= (1UL << 30))
1162 sprintf(buf, "%lu GB", n >> 30);
1163 else if (n >= (1UL << 20))
1164 sprintf(buf, "%lu MB", n >> 20);
1165 else
1166 sprintf(buf, "%lu KB", n >> 10);
1167 return buf;
1168}
1169
Andi Kleene5ff2152008-07-23 21:27:42 -07001170static void __init report_hugepages(void)
1171{
1172 struct hstate *h;
1173
1174 for_each_hstate(h) {
Andi Kleen4abd32d2008-07-23 21:27:49 -07001175 char buf[32];
1176 printk(KERN_INFO "HugeTLB registered %s page size, "
1177 "pre-allocated %ld pages\n",
1178 memfmt(buf, huge_page_size(h)),
1179 h->free_huge_pages);
Andi Kleene5ff2152008-07-23 21:27:42 -07001180 }
1181}
1182
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183#ifdef CONFIG_HIGHMEM
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001184static void try_to_free_low(struct hstate *h, unsigned long count,
1185 nodemask_t *nodes_allowed)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001186{
Christoph Lameter4415cc82006-09-25 23:31:55 -07001187 int i;
1188
Andi Kleenaa888a72008-07-23 21:27:47 -07001189 if (h->order >= MAX_ORDER)
1190 return;
1191
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001192 for_each_node_mask(i, *nodes_allowed) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193 struct page *page, *next;
Andi Kleena5516432008-07-23 21:27:41 -07001194 struct list_head *freel = &h->hugepage_freelists[i];
1195 list_for_each_entry_safe(page, next, freel, lru) {
1196 if (count >= h->nr_huge_pages)
Adam Litke6b0c8802007-10-16 01:26:23 -07001197 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198 if (PageHighMem(page))
1199 continue;
1200 list_del(&page->lru);
Andi Kleene5ff2152008-07-23 21:27:42 -07001201 update_and_free_page(h, page);
Andi Kleena5516432008-07-23 21:27:41 -07001202 h->free_huge_pages--;
1203 h->free_huge_pages_node[page_to_nid(page)]--;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001204 }
1205 }
1206}
1207#else
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001208static inline void try_to_free_low(struct hstate *h, unsigned long count,
1209 nodemask_t *nodes_allowed)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001210{
1211}
1212#endif
1213
Wu Fengguang20a03072009-06-16 15:32:22 -07001214/*
1215 * Increment or decrement surplus_huge_pages. Keep node-specific counters
1216 * balanced by operating on them in a round-robin fashion.
1217 * Returns 1 if an adjustment was made.
1218 */
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001219static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed,
1220 int delta)
Wu Fengguang20a03072009-06-16 15:32:22 -07001221{
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001222 int start_nid, next_nid;
Wu Fengguang20a03072009-06-16 15:32:22 -07001223 int ret = 0;
1224
1225 VM_BUG_ON(delta != -1 && delta != 1);
Wu Fengguang20a03072009-06-16 15:32:22 -07001226
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001227 if (delta < 0)
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001228 start_nid = hstate_next_node_to_alloc(h, nodes_allowed);
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001229 else
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001230 start_nid = hstate_next_node_to_free(h, nodes_allowed);
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001231 next_nid = start_nid;
1232
1233 do {
1234 int nid = next_nid;
1235 if (delta < 0) {
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001236 /*
1237 * To shrink on this node, there must be a surplus page
1238 */
Lee Schermerhorn9a76db02009-12-14 17:58:15 -08001239 if (!h->surplus_huge_pages_node[nid]) {
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001240 next_nid = hstate_next_node_to_alloc(h,
1241 nodes_allowed);
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001242 continue;
Lee Schermerhorn9a76db02009-12-14 17:58:15 -08001243 }
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001244 }
1245 if (delta > 0) {
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001246 /*
1247 * Surplus cannot exceed the total number of pages
1248 */
1249 if (h->surplus_huge_pages_node[nid] >=
Lee Schermerhorn9a76db02009-12-14 17:58:15 -08001250 h->nr_huge_pages_node[nid]) {
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001251 next_nid = hstate_next_node_to_free(h,
1252 nodes_allowed);
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001253 continue;
Lee Schermerhorn9a76db02009-12-14 17:58:15 -08001254 }
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001255 }
Wu Fengguang20a03072009-06-16 15:32:22 -07001256
1257 h->surplus_huge_pages += delta;
1258 h->surplus_huge_pages_node[nid] += delta;
1259 ret = 1;
1260 break;
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001261 } while (next_nid != start_nid);
Wu Fengguang20a03072009-06-16 15:32:22 -07001262
Wu Fengguang20a03072009-06-16 15:32:22 -07001263 return ret;
1264}
1265
Andi Kleena5516432008-07-23 21:27:41 -07001266#define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001267static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count,
1268 nodemask_t *nodes_allowed)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269{
Adam Litke7893d1d2007-10-16 01:26:18 -07001270 unsigned long min_count, ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001271
Andi Kleenaa888a72008-07-23 21:27:47 -07001272 if (h->order >= MAX_ORDER)
1273 return h->max_huge_pages;
1274
Adam Litke7893d1d2007-10-16 01:26:18 -07001275 /*
1276 * Increase the pool size
1277 * First take pages out of surplus state. Then make up the
1278 * remaining difference by allocating fresh huge pages.
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -08001279 *
1280 * We might race with alloc_buddy_huge_page() here and be unable
1281 * to convert a surplus huge page to a normal huge page. That is
1282 * not critical, though, it just means the overall size of the
1283 * pool might be one hugepage larger than it needs to be, but
1284 * within all the constraints specified by the sysctls.
Adam Litke7893d1d2007-10-16 01:26:18 -07001285 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -07001287 while (h->surplus_huge_pages && count > persistent_huge_pages(h)) {
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001288 if (!adjust_pool_surplus(h, nodes_allowed, -1))
Adam Litke7893d1d2007-10-16 01:26:18 -07001289 break;
1290 }
1291
Andi Kleena5516432008-07-23 21:27:41 -07001292 while (count > persistent_huge_pages(h)) {
Adam Litke7893d1d2007-10-16 01:26:18 -07001293 /*
1294 * If this allocation races such that we no longer need the
1295 * page, free_huge_page will handle it by freeing the page
1296 * and reducing the surplus.
1297 */
1298 spin_unlock(&hugetlb_lock);
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001299 ret = alloc_fresh_huge_page(h, nodes_allowed);
Adam Litke7893d1d2007-10-16 01:26:18 -07001300 spin_lock(&hugetlb_lock);
1301 if (!ret)
1302 goto out;
1303
Mel Gorman536240f22009-12-14 17:59:56 -08001304 /* Bail for signals. Probably ctrl-c from user */
1305 if (signal_pending(current))
1306 goto out;
Adam Litke7893d1d2007-10-16 01:26:18 -07001307 }
Adam Litke7893d1d2007-10-16 01:26:18 -07001308
1309 /*
1310 * Decrease the pool size
1311 * First return free pages to the buddy allocator (being careful
1312 * to keep enough around to satisfy reservations). Then place
1313 * pages into surplus state as needed so the pool will shrink
1314 * to the desired size as pages become free.
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -08001315 *
1316 * By placing pages into the surplus state independent of the
1317 * overcommit value, we are allowing the surplus pool size to
1318 * exceed overcommit. There are few sane options here. Since
1319 * alloc_buddy_huge_page() is checking the global counter,
1320 * though, we'll note that we're not allowed to exceed surplus
1321 * and won't grow the pool anywhere else. Not until one of the
1322 * sysctls are changed, or the surplus pages go out of use.
Adam Litke7893d1d2007-10-16 01:26:18 -07001323 */
Andi Kleena5516432008-07-23 21:27:41 -07001324 min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages;
Adam Litke6b0c8802007-10-16 01:26:23 -07001325 min_count = max(count, min_count);
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001326 try_to_free_low(h, min_count, nodes_allowed);
Andi Kleena5516432008-07-23 21:27:41 -07001327 while (min_count < persistent_huge_pages(h)) {
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001328 if (!free_pool_huge_page(h, nodes_allowed, 0))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330 }
Andi Kleena5516432008-07-23 21:27:41 -07001331 while (count < persistent_huge_pages(h)) {
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001332 if (!adjust_pool_surplus(h, nodes_allowed, 1))
Adam Litke7893d1d2007-10-16 01:26:18 -07001333 break;
1334 }
1335out:
Andi Kleena5516432008-07-23 21:27:41 -07001336 ret = persistent_huge_pages(h);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001337 spin_unlock(&hugetlb_lock);
Adam Litke7893d1d2007-10-16 01:26:18 -07001338 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001339}
1340
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001341#define HSTATE_ATTR_RO(_name) \
1342 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
1343
1344#define HSTATE_ATTR(_name) \
1345 static struct kobj_attribute _name##_attr = \
1346 __ATTR(_name, 0644, _name##_show, _name##_store)
1347
1348static struct kobject *hugepages_kobj;
1349static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];
1350
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001351static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp);
1352
1353static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp)
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001354{
1355 int i;
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001356
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001357 for (i = 0; i < HUGE_MAX_HSTATE; i++)
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001358 if (hstate_kobjs[i] == kobj) {
1359 if (nidp)
1360 *nidp = NUMA_NO_NODE;
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001361 return &hstates[i];
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001362 }
1363
1364 return kobj_to_node_hstate(kobj, nidp);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001365}
1366
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001367static ssize_t nr_hugepages_show_common(struct kobject *kobj,
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001368 struct kobj_attribute *attr, char *buf)
1369{
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001370 struct hstate *h;
1371 unsigned long nr_huge_pages;
1372 int nid;
1373
1374 h = kobj_to_hstate(kobj, &nid);
1375 if (nid == NUMA_NO_NODE)
1376 nr_huge_pages = h->nr_huge_pages;
1377 else
1378 nr_huge_pages = h->nr_huge_pages_node[nid];
1379
1380 return sprintf(buf, "%lu\n", nr_huge_pages);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001381}
Eric B Munsonadbe8722011-01-13 15:47:27 -08001382
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001383static ssize_t nr_hugepages_store_common(bool obey_mempolicy,
1384 struct kobject *kobj, struct kobj_attribute *attr,
1385 const char *buf, size_t len)
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001386{
1387 int err;
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001388 int nid;
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001389 unsigned long count;
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001390 struct hstate *h;
David Rientjesbad44b52009-12-14 17:58:38 -08001391 NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001392
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001393 err = strict_strtoul(buf, 10, &count);
Eric B Munson73ae31e2011-01-13 15:47:28 -08001394 if (err)
Eric B Munsonadbe8722011-01-13 15:47:27 -08001395 goto out;
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001396
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001397 h = kobj_to_hstate(kobj, &nid);
Eric B Munsonadbe8722011-01-13 15:47:27 -08001398 if (h->order >= MAX_ORDER) {
1399 err = -EINVAL;
1400 goto out;
1401 }
1402
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001403 if (nid == NUMA_NO_NODE) {
1404 /*
1405 * global hstate attribute
1406 */
1407 if (!(obey_mempolicy &&
1408 init_nodemask_of_mempolicy(nodes_allowed))) {
1409 NODEMASK_FREE(nodes_allowed);
1410 nodes_allowed = &node_states[N_HIGH_MEMORY];
1411 }
1412 } else if (nodes_allowed) {
1413 /*
1414 * per node hstate attribute: adjust count to global,
1415 * but restrict alloc/free to the specified node.
1416 */
1417 count += h->nr_huge_pages - h->nr_huge_pages_node[nid];
1418 init_nodemask_of_node(nodes_allowed, nid);
1419 } else
1420 nodes_allowed = &node_states[N_HIGH_MEMORY];
1421
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001422 h->max_huge_pages = set_max_huge_pages(h, count, nodes_allowed);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001423
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -08001424 if (nodes_allowed != &node_states[N_HIGH_MEMORY])
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001425 NODEMASK_FREE(nodes_allowed);
1426
1427 return len;
Eric B Munsonadbe8722011-01-13 15:47:27 -08001428out:
1429 NODEMASK_FREE(nodes_allowed);
1430 return err;
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001431}
1432
1433static ssize_t nr_hugepages_show(struct kobject *kobj,
1434 struct kobj_attribute *attr, char *buf)
1435{
1436 return nr_hugepages_show_common(kobj, attr, buf);
1437}
1438
1439static ssize_t nr_hugepages_store(struct kobject *kobj,
1440 struct kobj_attribute *attr, const char *buf, size_t len)
1441{
1442 return nr_hugepages_store_common(false, kobj, attr, buf, len);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001443}
1444HSTATE_ATTR(nr_hugepages);
1445
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001446#ifdef CONFIG_NUMA
1447
1448/*
1449 * hstate attribute for optionally mempolicy-based constraint on persistent
1450 * huge page alloc/free.
1451 */
1452static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj,
1453 struct kobj_attribute *attr, char *buf)
1454{
1455 return nr_hugepages_show_common(kobj, attr, buf);
1456}
1457
1458static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj,
1459 struct kobj_attribute *attr, const char *buf, size_t len)
1460{
1461 return nr_hugepages_store_common(true, kobj, attr, buf, len);
1462}
1463HSTATE_ATTR(nr_hugepages_mempolicy);
1464#endif
1465
1466
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001467static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj,
1468 struct kobj_attribute *attr, char *buf)
1469{
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001470 struct hstate *h = kobj_to_hstate(kobj, NULL);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001471 return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages);
1472}
Eric B Munsonadbe8722011-01-13 15:47:27 -08001473
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001474static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj,
1475 struct kobj_attribute *attr, const char *buf, size_t count)
1476{
1477 int err;
1478 unsigned long input;
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001479 struct hstate *h = kobj_to_hstate(kobj, NULL);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001480
Eric B Munsonadbe8722011-01-13 15:47:27 -08001481 if (h->order >= MAX_ORDER)
1482 return -EINVAL;
1483
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001484 err = strict_strtoul(buf, 10, &input);
1485 if (err)
Eric B Munson73ae31e2011-01-13 15:47:28 -08001486 return err;
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001487
1488 spin_lock(&hugetlb_lock);
1489 h->nr_overcommit_huge_pages = input;
1490 spin_unlock(&hugetlb_lock);
1491
1492 return count;
1493}
1494HSTATE_ATTR(nr_overcommit_hugepages);
1495
1496static ssize_t free_hugepages_show(struct kobject *kobj,
1497 struct kobj_attribute *attr, char *buf)
1498{
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001499 struct hstate *h;
1500 unsigned long free_huge_pages;
1501 int nid;
1502
1503 h = kobj_to_hstate(kobj, &nid);
1504 if (nid == NUMA_NO_NODE)
1505 free_huge_pages = h->free_huge_pages;
1506 else
1507 free_huge_pages = h->free_huge_pages_node[nid];
1508
1509 return sprintf(buf, "%lu\n", free_huge_pages);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001510}
1511HSTATE_ATTR_RO(free_hugepages);
1512
1513static ssize_t resv_hugepages_show(struct kobject *kobj,
1514 struct kobj_attribute *attr, char *buf)
1515{
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001516 struct hstate *h = kobj_to_hstate(kobj, NULL);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001517 return sprintf(buf, "%lu\n", h->resv_huge_pages);
1518}
1519HSTATE_ATTR_RO(resv_hugepages);
1520
1521static ssize_t surplus_hugepages_show(struct kobject *kobj,
1522 struct kobj_attribute *attr, char *buf)
1523{
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001524 struct hstate *h;
1525 unsigned long surplus_huge_pages;
1526 int nid;
1527
1528 h = kobj_to_hstate(kobj, &nid);
1529 if (nid == NUMA_NO_NODE)
1530 surplus_huge_pages = h->surplus_huge_pages;
1531 else
1532 surplus_huge_pages = h->surplus_huge_pages_node[nid];
1533
1534 return sprintf(buf, "%lu\n", surplus_huge_pages);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001535}
1536HSTATE_ATTR_RO(surplus_hugepages);
1537
1538static struct attribute *hstate_attrs[] = {
1539 &nr_hugepages_attr.attr,
1540 &nr_overcommit_hugepages_attr.attr,
1541 &free_hugepages_attr.attr,
1542 &resv_hugepages_attr.attr,
1543 &surplus_hugepages_attr.attr,
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001544#ifdef CONFIG_NUMA
1545 &nr_hugepages_mempolicy_attr.attr,
1546#endif
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001547 NULL,
1548};
1549
1550static struct attribute_group hstate_attr_group = {
1551 .attrs = hstate_attrs,
1552};
1553
Jeff Mahoney094e9532010-02-02 13:44:14 -08001554static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent,
1555 struct kobject **hstate_kobjs,
1556 struct attribute_group *hstate_attr_group)
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001557{
1558 int retval;
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001559 int hi = h - hstates;
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001560
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001561 hstate_kobjs[hi] = kobject_create_and_add(h->name, parent);
1562 if (!hstate_kobjs[hi])
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001563 return -ENOMEM;
1564
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001565 retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001566 if (retval)
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001567 kobject_put(hstate_kobjs[hi]);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001568
1569 return retval;
1570}
1571
1572static void __init hugetlb_sysfs_init(void)
1573{
1574 struct hstate *h;
1575 int err;
1576
1577 hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj);
1578 if (!hugepages_kobj)
1579 return;
1580
1581 for_each_hstate(h) {
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001582 err = hugetlb_sysfs_add_hstate(h, hugepages_kobj,
1583 hstate_kobjs, &hstate_attr_group);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001584 if (err)
1585 printk(KERN_ERR "Hugetlb: Unable to add hstate %s",
1586 h->name);
1587 }
1588}
1589
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001590#ifdef CONFIG_NUMA
1591
1592/*
1593 * node_hstate/s - associate per node hstate attributes, via their kobjects,
1594 * with node sysdevs in node_devices[] using a parallel array. The array
1595 * index of a node sysdev or _hstate == node id.
1596 * This is here to avoid any static dependency of the node sysdev driver, in
1597 * the base kernel, on the hugetlb module.
1598 */
1599struct node_hstate {
1600 struct kobject *hugepages_kobj;
1601 struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];
1602};
1603struct node_hstate node_hstates[MAX_NUMNODES];
1604
1605/*
1606 * A subset of global hstate attributes for node sysdevs
1607 */
1608static struct attribute *per_node_hstate_attrs[] = {
1609 &nr_hugepages_attr.attr,
1610 &free_hugepages_attr.attr,
1611 &surplus_hugepages_attr.attr,
1612 NULL,
1613};
1614
1615static struct attribute_group per_node_hstate_attr_group = {
1616 .attrs = per_node_hstate_attrs,
1617};
1618
1619/*
1620 * kobj_to_node_hstate - lookup global hstate for node sysdev hstate attr kobj.
1621 * Returns node id via non-NULL nidp.
1622 */
1623static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp)
1624{
1625 int nid;
1626
1627 for (nid = 0; nid < nr_node_ids; nid++) {
1628 struct node_hstate *nhs = &node_hstates[nid];
1629 int i;
1630 for (i = 0; i < HUGE_MAX_HSTATE; i++)
1631 if (nhs->hstate_kobjs[i] == kobj) {
1632 if (nidp)
1633 *nidp = nid;
1634 return &hstates[i];
1635 }
1636 }
1637
1638 BUG();
1639 return NULL;
1640}
1641
1642/*
1643 * Unregister hstate attributes from a single node sysdev.
1644 * No-op if no hstate attributes attached.
1645 */
1646void hugetlb_unregister_node(struct node *node)
1647{
1648 struct hstate *h;
1649 struct node_hstate *nhs = &node_hstates[node->sysdev.id];
1650
1651 if (!nhs->hugepages_kobj)
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -08001652 return; /* no hstate attributes */
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001653
1654 for_each_hstate(h)
1655 if (nhs->hstate_kobjs[h - hstates]) {
1656 kobject_put(nhs->hstate_kobjs[h - hstates]);
1657 nhs->hstate_kobjs[h - hstates] = NULL;
1658 }
1659
1660 kobject_put(nhs->hugepages_kobj);
1661 nhs->hugepages_kobj = NULL;
1662}
1663
1664/*
1665 * hugetlb module exit: unregister hstate attributes from node sysdevs
1666 * that have them.
1667 */
1668static void hugetlb_unregister_all_nodes(void)
1669{
1670 int nid;
1671
1672 /*
1673 * disable node sysdev registrations.
1674 */
1675 register_hugetlbfs_with_node(NULL, NULL);
1676
1677 /*
1678 * remove hstate attributes from any nodes that have them.
1679 */
1680 for (nid = 0; nid < nr_node_ids; nid++)
1681 hugetlb_unregister_node(&node_devices[nid]);
1682}
1683
1684/*
1685 * Register hstate attributes for a single node sysdev.
1686 * No-op if attributes already registered.
1687 */
1688void hugetlb_register_node(struct node *node)
1689{
1690 struct hstate *h;
1691 struct node_hstate *nhs = &node_hstates[node->sysdev.id];
1692 int err;
1693
1694 if (nhs->hugepages_kobj)
1695 return; /* already allocated */
1696
1697 nhs->hugepages_kobj = kobject_create_and_add("hugepages",
1698 &node->sysdev.kobj);
1699 if (!nhs->hugepages_kobj)
1700 return;
1701
1702 for_each_hstate(h) {
1703 err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj,
1704 nhs->hstate_kobjs,
1705 &per_node_hstate_attr_group);
1706 if (err) {
1707 printk(KERN_ERR "Hugetlb: Unable to add hstate %s"
1708 " for node %d\n",
1709 h->name, node->sysdev.id);
1710 hugetlb_unregister_node(node);
1711 break;
1712 }
1713 }
1714}
1715
1716/*
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -08001717 * hugetlb init time: register hstate attributes for all registered node
1718 * sysdevs of nodes that have memory. All on-line nodes should have
1719 * registered their associated sysdev by this time.
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001720 */
1721static void hugetlb_register_all_nodes(void)
1722{
1723 int nid;
1724
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -08001725 for_each_node_state(nid, N_HIGH_MEMORY) {
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001726 struct node *node = &node_devices[nid];
1727 if (node->sysdev.id == nid)
1728 hugetlb_register_node(node);
1729 }
1730
1731 /*
1732 * Let the node sysdev driver know we're here so it can
1733 * [un]register hstate attributes on node hotplug.
1734 */
1735 register_hugetlbfs_with_node(hugetlb_register_node,
1736 hugetlb_unregister_node);
1737}
1738#else /* !CONFIG_NUMA */
1739
1740static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp)
1741{
1742 BUG();
1743 if (nidp)
1744 *nidp = -1;
1745 return NULL;
1746}
1747
1748static void hugetlb_unregister_all_nodes(void) { }
1749
1750static void hugetlb_register_all_nodes(void) { }
1751
1752#endif
1753
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001754static void __exit hugetlb_exit(void)
1755{
1756 struct hstate *h;
1757
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001758 hugetlb_unregister_all_nodes();
1759
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001760 for_each_hstate(h) {
1761 kobject_put(hstate_kobjs[h - hstates]);
1762 }
1763
1764 kobject_put(hugepages_kobj);
1765}
1766module_exit(hugetlb_exit);
1767
1768static int __init hugetlb_init(void)
1769{
Benjamin Herrenschmidt0ef89d22008-07-31 00:07:30 -07001770 /* Some platform decide whether they support huge pages at boot
1771 * time. On these, such as powerpc, HPAGE_SHIFT is set to 0 when
1772 * there is no such support
1773 */
1774 if (HPAGE_SHIFT == 0)
1775 return 0;
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001776
Nick Piggine11bfbf2008-07-23 21:27:52 -07001777 if (!size_to_hstate(default_hstate_size)) {
1778 default_hstate_size = HPAGE_SIZE;
1779 if (!size_to_hstate(default_hstate_size))
1780 hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001781 }
Nick Piggine11bfbf2008-07-23 21:27:52 -07001782 default_hstate_idx = size_to_hstate(default_hstate_size) - hstates;
1783 if (default_hstate_max_huge_pages)
1784 default_hstate.max_huge_pages = default_hstate_max_huge_pages;
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001785
1786 hugetlb_init_hstates();
1787
Andi Kleenaa888a72008-07-23 21:27:47 -07001788 gather_bootmem_prealloc();
1789
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001790 report_hugepages();
1791
1792 hugetlb_sysfs_init();
1793
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001794 hugetlb_register_all_nodes();
1795
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001796 return 0;
1797}
1798module_init(hugetlb_init);
1799
1800/* Should be called on processing a hugepagesz=... option */
1801void __init hugetlb_add_hstate(unsigned order)
1802{
1803 struct hstate *h;
Andi Kleen8faa8b02008-07-23 21:27:48 -07001804 unsigned long i;
1805
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001806 if (size_to_hstate(PAGE_SIZE << order)) {
1807 printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n");
1808 return;
1809 }
1810 BUG_ON(max_hstate >= HUGE_MAX_HSTATE);
1811 BUG_ON(order == 0);
1812 h = &hstates[max_hstate++];
1813 h->order = order;
1814 h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1);
Andi Kleen8faa8b02008-07-23 21:27:48 -07001815 h->nr_huge_pages = 0;
1816 h->free_huge_pages = 0;
1817 for (i = 0; i < MAX_NUMNODES; ++i)
1818 INIT_LIST_HEAD(&h->hugepage_freelists[i]);
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -08001819 h->next_nid_to_alloc = first_node(node_states[N_HIGH_MEMORY]);
1820 h->next_nid_to_free = first_node(node_states[N_HIGH_MEMORY]);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001821 snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
1822 huge_page_size(h)/1024);
Andi Kleen8faa8b02008-07-23 21:27:48 -07001823
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001824 parsed_hstate = h;
1825}
1826
Nick Piggine11bfbf2008-07-23 21:27:52 -07001827static int __init hugetlb_nrpages_setup(char *s)
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001828{
1829 unsigned long *mhp;
Andi Kleen8faa8b02008-07-23 21:27:48 -07001830 static unsigned long *last_mhp;
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001831
1832 /*
1833 * !max_hstate means we haven't parsed a hugepagesz= parameter yet,
1834 * so this hugepages= parameter goes to the "default hstate".
1835 */
1836 if (!max_hstate)
1837 mhp = &default_hstate_max_huge_pages;
1838 else
1839 mhp = &parsed_hstate->max_huge_pages;
1840
Andi Kleen8faa8b02008-07-23 21:27:48 -07001841 if (mhp == last_mhp) {
1842 printk(KERN_WARNING "hugepages= specified twice without "
1843 "interleaving hugepagesz=, ignoring\n");
1844 return 1;
1845 }
1846
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001847 if (sscanf(s, "%lu", mhp) <= 0)
1848 *mhp = 0;
1849
Andi Kleen8faa8b02008-07-23 21:27:48 -07001850 /*
1851 * Global state is always initialized later in hugetlb_init.
1852 * But we need to allocate >= MAX_ORDER hstates here early to still
1853 * use the bootmem allocator.
1854 */
1855 if (max_hstate && parsed_hstate->order >= MAX_ORDER)
1856 hugetlb_hstate_alloc_pages(parsed_hstate);
1857
1858 last_mhp = mhp;
1859
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001860 return 1;
1861}
Nick Piggine11bfbf2008-07-23 21:27:52 -07001862__setup("hugepages=", hugetlb_nrpages_setup);
1863
1864static int __init hugetlb_default_setup(char *s)
1865{
1866 default_hstate_size = memparse(s, &s);
1867 return 1;
1868}
1869__setup("default_hugepagesz=", hugetlb_default_setup);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001870
Nishanth Aravamudan8a213462008-07-25 19:44:37 -07001871static unsigned int cpuset_mems_nr(unsigned int *array)
1872{
1873 int node;
1874 unsigned int nr = 0;
1875
1876 for_each_node_mask(node, cpuset_current_mems_allowed)
1877 nr += array[node];
1878
1879 return nr;
1880}
1881
1882#ifdef CONFIG_SYSCTL
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001883static int hugetlb_sysctl_handler_common(bool obey_mempolicy,
1884 struct ctl_table *table, int write,
1885 void __user *buffer, size_t *length, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001886{
Andi Kleene5ff2152008-07-23 21:27:42 -07001887 struct hstate *h = &default_hstate;
1888 unsigned long tmp;
Michal Hocko08d4a242011-01-13 15:47:26 -08001889 int ret;
Andi Kleene5ff2152008-07-23 21:27:42 -07001890
Petr Holasekc033a932011-03-22 16:33:05 -07001891 tmp = h->max_huge_pages;
Andi Kleene5ff2152008-07-23 21:27:42 -07001892
Eric B Munsonadbe8722011-01-13 15:47:27 -08001893 if (write && h->order >= MAX_ORDER)
1894 return -EINVAL;
1895
Andi Kleene5ff2152008-07-23 21:27:42 -07001896 table->data = &tmp;
1897 table->maxlen = sizeof(unsigned long);
Michal Hocko08d4a242011-01-13 15:47:26 -08001898 ret = proc_doulongvec_minmax(table, write, buffer, length, ppos);
1899 if (ret)
1900 goto out;
Andi Kleene5ff2152008-07-23 21:27:42 -07001901
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001902 if (write) {
David Rientjesbad44b52009-12-14 17:58:38 -08001903 NODEMASK_ALLOC(nodemask_t, nodes_allowed,
1904 GFP_KERNEL | __GFP_NORETRY);
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001905 if (!(obey_mempolicy &&
1906 init_nodemask_of_mempolicy(nodes_allowed))) {
1907 NODEMASK_FREE(nodes_allowed);
1908 nodes_allowed = &node_states[N_HIGH_MEMORY];
1909 }
1910 h->max_huge_pages = set_max_huge_pages(h, tmp, nodes_allowed);
1911
1912 if (nodes_allowed != &node_states[N_HIGH_MEMORY])
1913 NODEMASK_FREE(nodes_allowed);
1914 }
Michal Hocko08d4a242011-01-13 15:47:26 -08001915out:
1916 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001917}
Mel Gorman396faf02007-07-17 04:03:13 -07001918
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001919int hugetlb_sysctl_handler(struct ctl_table *table, int write,
1920 void __user *buffer, size_t *length, loff_t *ppos)
1921{
1922
1923 return hugetlb_sysctl_handler_common(false, table, write,
1924 buffer, length, ppos);
1925}
1926
1927#ifdef CONFIG_NUMA
1928int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write,
1929 void __user *buffer, size_t *length, loff_t *ppos)
1930{
1931 return hugetlb_sysctl_handler_common(true, table, write,
1932 buffer, length, ppos);
1933}
1934#endif /* CONFIG_NUMA */
1935
Mel Gorman396faf02007-07-17 04:03:13 -07001936int hugetlb_treat_movable_handler(struct ctl_table *table, int write,
Alexey Dobriyan8d65af72009-09-23 15:57:19 -07001937 void __user *buffer,
Mel Gorman396faf02007-07-17 04:03:13 -07001938 size_t *length, loff_t *ppos)
1939{
Alexey Dobriyan8d65af72009-09-23 15:57:19 -07001940 proc_dointvec(table, write, buffer, length, ppos);
Mel Gorman396faf02007-07-17 04:03:13 -07001941 if (hugepages_treat_as_movable)
1942 htlb_alloc_mask = GFP_HIGHUSER_MOVABLE;
1943 else
1944 htlb_alloc_mask = GFP_HIGHUSER;
1945 return 0;
1946}
1947
Nishanth Aravamudana3d0c6a2008-02-08 04:18:18 -08001948int hugetlb_overcommit_handler(struct ctl_table *table, int write,
Alexey Dobriyan8d65af72009-09-23 15:57:19 -07001949 void __user *buffer,
Nishanth Aravamudana3d0c6a2008-02-08 04:18:18 -08001950 size_t *length, loff_t *ppos)
1951{
Andi Kleena5516432008-07-23 21:27:41 -07001952 struct hstate *h = &default_hstate;
Andi Kleene5ff2152008-07-23 21:27:42 -07001953 unsigned long tmp;
Michal Hocko08d4a242011-01-13 15:47:26 -08001954 int ret;
Andi Kleene5ff2152008-07-23 21:27:42 -07001955
Petr Holasekc033a932011-03-22 16:33:05 -07001956 tmp = h->nr_overcommit_huge_pages;
Andi Kleene5ff2152008-07-23 21:27:42 -07001957
Eric B Munsonadbe8722011-01-13 15:47:27 -08001958 if (write && h->order >= MAX_ORDER)
1959 return -EINVAL;
1960
Andi Kleene5ff2152008-07-23 21:27:42 -07001961 table->data = &tmp;
1962 table->maxlen = sizeof(unsigned long);
Michal Hocko08d4a242011-01-13 15:47:26 -08001963 ret = proc_doulongvec_minmax(table, write, buffer, length, ppos);
1964 if (ret)
1965 goto out;
Andi Kleene5ff2152008-07-23 21:27:42 -07001966
1967 if (write) {
1968 spin_lock(&hugetlb_lock);
1969 h->nr_overcommit_huge_pages = tmp;
1970 spin_unlock(&hugetlb_lock);
1971 }
Michal Hocko08d4a242011-01-13 15:47:26 -08001972out:
1973 return ret;
Nishanth Aravamudana3d0c6a2008-02-08 04:18:18 -08001974}
1975
Linus Torvalds1da177e2005-04-16 15:20:36 -07001976#endif /* CONFIG_SYSCTL */
1977
Alexey Dobriyane1759c22008-10-15 23:50:22 +04001978void hugetlb_report_meminfo(struct seq_file *m)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001979{
Andi Kleena5516432008-07-23 21:27:41 -07001980 struct hstate *h = &default_hstate;
Alexey Dobriyane1759c22008-10-15 23:50:22 +04001981 seq_printf(m,
Rik van Riel4f98a2f2008-10-18 20:26:32 -07001982 "HugePages_Total: %5lu\n"
1983 "HugePages_Free: %5lu\n"
1984 "HugePages_Rsvd: %5lu\n"
1985 "HugePages_Surp: %5lu\n"
1986 "Hugepagesize: %8lu kB\n",
Andi Kleena5516432008-07-23 21:27:41 -07001987 h->nr_huge_pages,
1988 h->free_huge_pages,
1989 h->resv_huge_pages,
1990 h->surplus_huge_pages,
1991 1UL << (huge_page_order(h) + PAGE_SHIFT - 10));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001992}
1993
1994int hugetlb_report_node_meminfo(int nid, char *buf)
1995{
Andi Kleena5516432008-07-23 21:27:41 -07001996 struct hstate *h = &default_hstate;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001997 return sprintf(buf,
1998 "Node %d HugePages_Total: %5u\n"
Nishanth Aravamudana1de0912008-03-26 14:37:53 -07001999 "Node %d HugePages_Free: %5u\n"
2000 "Node %d HugePages_Surp: %5u\n",
Andi Kleena5516432008-07-23 21:27:41 -07002001 nid, h->nr_huge_pages_node[nid],
2002 nid, h->free_huge_pages_node[nid],
2003 nid, h->surplus_huge_pages_node[nid]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002004}
2005
Linus Torvalds1da177e2005-04-16 15:20:36 -07002006/* Return the number pages of memory we physically have, in PAGE_SIZE units. */
2007unsigned long hugetlb_total_pages(void)
2008{
Andi Kleena5516432008-07-23 21:27:41 -07002009 struct hstate *h = &default_hstate;
2010 return h->nr_huge_pages * pages_per_huge_page(h);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002011}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002012
Andi Kleena5516432008-07-23 21:27:41 -07002013static int hugetlb_acct_memory(struct hstate *h, long delta)
Mel Gormanfc1b8a72008-07-23 21:27:22 -07002014{
2015 int ret = -ENOMEM;
2016
2017 spin_lock(&hugetlb_lock);
2018 /*
2019 * When cpuset is configured, it breaks the strict hugetlb page
2020 * reservation as the accounting is done on a global variable. Such
2021 * reservation is completely rubbish in the presence of cpuset because
2022 * the reservation is not checked against page availability for the
2023 * current cpuset. Application can still potentially OOM'ed by kernel
2024 * with lack of free htlb page in cpuset that the task is in.
2025 * Attempt to enforce strict accounting with cpuset is almost
2026 * impossible (or too ugly) because cpuset is too fluid that
2027 * task or memory node can be dynamically moved between cpusets.
2028 *
2029 * The change of semantics for shared hugetlb mapping with cpuset is
2030 * undesirable. However, in order to preserve some of the semantics,
2031 * we fall back to check against current free page availability as
2032 * a best attempt and hopefully to minimize the impact of changing
2033 * semantics that cpuset has.
2034 */
2035 if (delta > 0) {
Andi Kleena5516432008-07-23 21:27:41 -07002036 if (gather_surplus_pages(h, delta) < 0)
Mel Gormanfc1b8a72008-07-23 21:27:22 -07002037 goto out;
2038
Andi Kleena5516432008-07-23 21:27:41 -07002039 if (delta > cpuset_mems_nr(h->free_huge_pages_node)) {
2040 return_unused_surplus_pages(h, delta);
Mel Gormanfc1b8a72008-07-23 21:27:22 -07002041 goto out;
2042 }
2043 }
2044
2045 ret = 0;
2046 if (delta < 0)
Andi Kleena5516432008-07-23 21:27:41 -07002047 return_unused_surplus_pages(h, (unsigned long) -delta);
Mel Gormanfc1b8a72008-07-23 21:27:22 -07002048
2049out:
2050 spin_unlock(&hugetlb_lock);
2051 return ret;
2052}
2053
Andy Whitcroft84afd992008-07-23 21:27:32 -07002054static void hugetlb_vm_op_open(struct vm_area_struct *vma)
2055{
2056 struct resv_map *reservations = vma_resv_map(vma);
2057
2058 /*
2059 * This new VMA should share its siblings reservation map if present.
2060 * The VMA will only ever have a valid reservation map pointer where
2061 * it is being copied for another still existing VMA. As that VMA
Lucas De Marchi25985ed2011-03-30 22:57:33 -03002062 * has a reference to the reservation map it cannot disappear until
Andy Whitcroft84afd992008-07-23 21:27:32 -07002063 * after this open call completes. It is therefore safe to take a
2064 * new reference here without additional locking.
2065 */
2066 if (reservations)
2067 kref_get(&reservations->refs);
2068}
2069
Mel Gormana1e78772008-07-23 21:27:23 -07002070static void hugetlb_vm_op_close(struct vm_area_struct *vma)
2071{
Andi Kleena5516432008-07-23 21:27:41 -07002072 struct hstate *h = hstate_vma(vma);
Andy Whitcroft84afd992008-07-23 21:27:32 -07002073 struct resv_map *reservations = vma_resv_map(vma);
2074 unsigned long reserve;
2075 unsigned long start;
2076 unsigned long end;
2077
2078 if (reservations) {
Andi Kleena5516432008-07-23 21:27:41 -07002079 start = vma_hugecache_offset(h, vma, vma->vm_start);
2080 end = vma_hugecache_offset(h, vma, vma->vm_end);
Andy Whitcroft84afd992008-07-23 21:27:32 -07002081
2082 reserve = (end - start) -
2083 region_count(&reservations->regions, start, end);
2084
2085 kref_put(&reservations->refs, resv_map_release);
2086
Adam Litke7251ff72008-07-23 21:27:59 -07002087 if (reserve) {
Andi Kleena5516432008-07-23 21:27:41 -07002088 hugetlb_acct_memory(h, -reserve);
Adam Litke7251ff72008-07-23 21:27:59 -07002089 hugetlb_put_quota(vma->vm_file->f_mapping, reserve);
2090 }
Andy Whitcroft84afd992008-07-23 21:27:32 -07002091 }
Mel Gormana1e78772008-07-23 21:27:23 -07002092}
2093
Linus Torvalds1da177e2005-04-16 15:20:36 -07002094/*
2095 * We cannot handle pagefaults against hugetlb pages at all. They cause
2096 * handle_mm_fault() to try to instantiate regular-sized pages in the
2097 * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get
2098 * this far.
2099 */
Nick Piggind0217ac2007-07-19 01:47:03 -07002100static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002101{
2102 BUG();
Nick Piggind0217ac2007-07-19 01:47:03 -07002103 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002104}
2105
Alexey Dobriyanf0f37e22009-09-27 22:29:37 +04002106const struct vm_operations_struct hugetlb_vm_ops = {
Nick Piggind0217ac2007-07-19 01:47:03 -07002107 .fault = hugetlb_vm_op_fault,
Andy Whitcroft84afd992008-07-23 21:27:32 -07002108 .open = hugetlb_vm_op_open,
Mel Gormana1e78772008-07-23 21:27:23 -07002109 .close = hugetlb_vm_op_close,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002110};
2111
David Gibson1e8f8892006-01-06 00:10:44 -08002112static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page,
2113 int writable)
David Gibson63551ae2005-06-21 17:14:44 -07002114{
2115 pte_t entry;
2116
David Gibson1e8f8892006-01-06 00:10:44 -08002117 if (writable) {
David Gibson63551ae2005-06-21 17:14:44 -07002118 entry =
2119 pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
2120 } else {
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002121 entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot));
David Gibson63551ae2005-06-21 17:14:44 -07002122 }
2123 entry = pte_mkyoung(entry);
2124 entry = pte_mkhuge(entry);
2125
2126 return entry;
2127}
2128
David Gibson1e8f8892006-01-06 00:10:44 -08002129static void set_huge_ptep_writable(struct vm_area_struct *vma,
2130 unsigned long address, pte_t *ptep)
2131{
2132 pte_t entry;
2133
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002134 entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep)));
Chris Forbes32f84522011-07-25 17:12:14 -07002135 if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1))
Russell King4b3073e2009-12-18 16:40:18 +00002136 update_mmu_cache(vma, address, ptep);
David Gibson1e8f8892006-01-06 00:10:44 -08002137}
2138
2139
David Gibson63551ae2005-06-21 17:14:44 -07002140int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
2141 struct vm_area_struct *vma)
2142{
2143 pte_t *src_pte, *dst_pte, entry;
2144 struct page *ptepage;
Hugh Dickins1c598272005-10-19 21:23:43 -07002145 unsigned long addr;
David Gibson1e8f8892006-01-06 00:10:44 -08002146 int cow;
Andi Kleena5516432008-07-23 21:27:41 -07002147 struct hstate *h = hstate_vma(vma);
2148 unsigned long sz = huge_page_size(h);
David Gibson1e8f8892006-01-06 00:10:44 -08002149
2150 cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
David Gibson63551ae2005-06-21 17:14:44 -07002151
Andi Kleena5516432008-07-23 21:27:41 -07002152 for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
Hugh Dickinsc74df322005-10-29 18:16:23 -07002153 src_pte = huge_pte_offset(src, addr);
2154 if (!src_pte)
2155 continue;
Andi Kleena5516432008-07-23 21:27:41 -07002156 dst_pte = huge_pte_alloc(dst, addr, sz);
David Gibson63551ae2005-06-21 17:14:44 -07002157 if (!dst_pte)
2158 goto nomem;
Larry Woodmanc5c99422008-01-24 05:49:25 -08002159
2160 /* If the pagetables are shared don't copy or take references */
2161 if (dst_pte == src_pte)
2162 continue;
2163
Hugh Dickinsc74df322005-10-29 18:16:23 -07002164 spin_lock(&dst->page_table_lock);
Nick Piggin46478752008-06-05 22:45:57 -07002165 spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING);
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002166 if (!huge_pte_none(huge_ptep_get(src_pte))) {
David Gibson1e8f8892006-01-06 00:10:44 -08002167 if (cow)
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002168 huge_ptep_set_wrprotect(src, addr, src_pte);
2169 entry = huge_ptep_get(src_pte);
Hugh Dickins1c598272005-10-19 21:23:43 -07002170 ptepage = pte_page(entry);
2171 get_page(ptepage);
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002172 page_dup_rmap(ptepage);
Hugh Dickins1c598272005-10-19 21:23:43 -07002173 set_huge_pte_at(dst, addr, dst_pte, entry);
2174 }
2175 spin_unlock(&src->page_table_lock);
Hugh Dickinsc74df322005-10-29 18:16:23 -07002176 spin_unlock(&dst->page_table_lock);
David Gibson63551ae2005-06-21 17:14:44 -07002177 }
2178 return 0;
2179
2180nomem:
2181 return -ENOMEM;
2182}
2183
Naoya Horiguchi290408d2010-09-08 10:19:35 +09002184static int is_hugetlb_entry_migration(pte_t pte)
2185{
2186 swp_entry_t swp;
2187
2188 if (huge_pte_none(pte) || pte_present(pte))
2189 return 0;
2190 swp = pte_to_swp_entry(pte);
Chris Forbes32f84522011-07-25 17:12:14 -07002191 if (non_swap_entry(swp) && is_migration_entry(swp))
Naoya Horiguchi290408d2010-09-08 10:19:35 +09002192 return 1;
Chris Forbes32f84522011-07-25 17:12:14 -07002193 else
Naoya Horiguchi290408d2010-09-08 10:19:35 +09002194 return 0;
2195}
2196
Naoya Horiguchifd6a03ed2010-05-28 09:29:21 +09002197static int is_hugetlb_entry_hwpoisoned(pte_t pte)
2198{
2199 swp_entry_t swp;
2200
2201 if (huge_pte_none(pte) || pte_present(pte))
2202 return 0;
2203 swp = pte_to_swp_entry(pte);
Chris Forbes32f84522011-07-25 17:12:14 -07002204 if (non_swap_entry(swp) && is_hwpoison_entry(swp))
Naoya Horiguchifd6a03ed2010-05-28 09:29:21 +09002205 return 1;
Chris Forbes32f84522011-07-25 17:12:14 -07002206 else
Naoya Horiguchifd6a03ed2010-05-28 09:29:21 +09002207 return 0;
2208}
2209
Chen, Kenneth W502717f2006-10-11 01:20:46 -07002210void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002211 unsigned long end, struct page *ref_page)
David Gibson63551ae2005-06-21 17:14:44 -07002212{
2213 struct mm_struct *mm = vma->vm_mm;
2214 unsigned long address;
David Gibsonc7546f82005-08-05 11:59:35 -07002215 pte_t *ptep;
David Gibson63551ae2005-06-21 17:14:44 -07002216 pte_t pte;
2217 struct page *page;
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07002218 struct page *tmp;
Andi Kleena5516432008-07-23 21:27:41 -07002219 struct hstate *h = hstate_vma(vma);
2220 unsigned long sz = huge_page_size(h);
2221
Chen, Kenneth Wc0a499c2006-12-06 20:31:39 -08002222 /*
Peter Zijlstra3d48ae42011-05-24 17:12:06 -07002223 * A page gathering list, protected by per file i_mmap_mutex. The
Chen, Kenneth Wc0a499c2006-12-06 20:31:39 -08002224 * lock is used to avoid list corruption from multiple unmapping
2225 * of the same page since we are using page->lru.
2226 */
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07002227 LIST_HEAD(page_list);
David Gibson63551ae2005-06-21 17:14:44 -07002228
2229 WARN_ON(!is_vm_hugetlb_page(vma));
Andi Kleena5516432008-07-23 21:27:41 -07002230 BUG_ON(start & ~huge_page_mask(h));
2231 BUG_ON(end & ~huge_page_mask(h));
David Gibson63551ae2005-06-21 17:14:44 -07002232
Andrea Arcangelicddb8a52008-07-28 15:46:29 -07002233 mmu_notifier_invalidate_range_start(mm, start, end);
Hugh Dickins508034a2005-10-29 18:16:30 -07002234 spin_lock(&mm->page_table_lock);
Andi Kleena5516432008-07-23 21:27:41 -07002235 for (address = start; address < end; address += sz) {
David Gibsonc7546f82005-08-05 11:59:35 -07002236 ptep = huge_pte_offset(mm, address);
Adam Litke4c887262005-10-29 18:16:46 -07002237 if (!ptep)
David Gibsonc7546f82005-08-05 11:59:35 -07002238 continue;
2239
Chen, Kenneth W39dde652006-12-06 20:32:03 -08002240 if (huge_pmd_unshare(mm, &address, ptep))
2241 continue;
2242
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002243 /*
2244 * If a reference page is supplied, it is because a specific
2245 * page is being unmapped, not a range. Ensure the page we
2246 * are about to unmap is the actual page of interest.
2247 */
2248 if (ref_page) {
2249 pte = huge_ptep_get(ptep);
2250 if (huge_pte_none(pte))
2251 continue;
2252 page = pte_page(pte);
2253 if (page != ref_page)
2254 continue;
2255
2256 /*
2257 * Mark the VMA as having unmapped its page so that
2258 * future faults in this VMA will fail rather than
2259 * looking like data was lost
2260 */
2261 set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED);
2262 }
2263
David Gibsonc7546f82005-08-05 11:59:35 -07002264 pte = huge_ptep_get_and_clear(mm, address, ptep);
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002265 if (huge_pte_none(pte))
David Gibson63551ae2005-06-21 17:14:44 -07002266 continue;
David Gibsonc7546f82005-08-05 11:59:35 -07002267
Naoya Horiguchifd6a03ed2010-05-28 09:29:21 +09002268 /*
2269 * HWPoisoned hugepage is already unmapped and dropped reference
2270 */
2271 if (unlikely(is_hugetlb_entry_hwpoisoned(pte)))
2272 continue;
2273
David Gibson63551ae2005-06-21 17:14:44 -07002274 page = pte_page(pte);
Ken Chen6649a382007-02-08 14:20:27 -08002275 if (pte_dirty(pte))
2276 set_page_dirty(page);
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07002277 list_add(&page->lru, &page_list);
David Gibson63551ae2005-06-21 17:14:44 -07002278 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002279 spin_unlock(&mm->page_table_lock);
Hugh Dickins508034a2005-10-29 18:16:30 -07002280 flush_tlb_range(vma, start, end);
Andrea Arcangelicddb8a52008-07-28 15:46:29 -07002281 mmu_notifier_invalidate_range_end(mm, start, end);
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07002282 list_for_each_entry_safe(page, tmp, &page_list, lru) {
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002283 page_remove_rmap(page);
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07002284 list_del(&page->lru);
2285 put_page(page);
2286 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002287}
David Gibson63551ae2005-06-21 17:14:44 -07002288
Chen, Kenneth W502717f2006-10-11 01:20:46 -07002289void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002290 unsigned long end, struct page *ref_page)
Chen, Kenneth W502717f2006-10-11 01:20:46 -07002291{
Peter Zijlstra3d48ae42011-05-24 17:12:06 -07002292 mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex);
Andi Kleena137e1c2008-07-23 21:27:43 -07002293 __unmap_hugepage_range(vma, start, end, ref_page);
Peter Zijlstra3d48ae42011-05-24 17:12:06 -07002294 mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
Chen, Kenneth W502717f2006-10-11 01:20:46 -07002295}
2296
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002297/*
2298 * This is called when the original mapper is failing to COW a MAP_PRIVATE
2299 * mappping it owns the reserve page for. The intention is to unmap the page
2300 * from other VMAs and let the children be SIGKILLed if they are faulting the
2301 * same region.
2302 */
Harvey Harrison2a4b3de2008-10-18 20:27:06 -07002303static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
2304 struct page *page, unsigned long address)
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002305{
Adam Litke75266742008-11-12 13:24:56 -08002306 struct hstate *h = hstate_vma(vma);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002307 struct vm_area_struct *iter_vma;
2308 struct address_space *mapping;
2309 struct prio_tree_iter iter;
2310 pgoff_t pgoff;
2311
2312 /*
2313 * vm_pgoff is in PAGE_SIZE units, hence the different calculation
2314 * from page cache lookup which is in HPAGE_SIZE units.
2315 */
Adam Litke75266742008-11-12 13:24:56 -08002316 address = address & huge_page_mask(h);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002317 pgoff = ((address - vma->vm_start) >> PAGE_SHIFT)
2318 + (vma->vm_pgoff >> PAGE_SHIFT);
2319 mapping = (struct address_space *)page_private(page);
2320
Mel Gorman4eb2b1d2009-12-14 17:59:53 -08002321 /*
2322 * Take the mapping lock for the duration of the table walk. As
2323 * this mapping should be shared between all the VMAs,
2324 * __unmap_hugepage_range() is called as the lock is already held
2325 */
Peter Zijlstra3d48ae42011-05-24 17:12:06 -07002326 mutex_lock(&mapping->i_mmap_mutex);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002327 vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
2328 /* Do not unmap the current VMA */
2329 if (iter_vma == vma)
2330 continue;
2331
2332 /*
2333 * Unmap the page from other VMAs without their own reserves.
2334 * They get marked to be SIGKILLed if they fault in these
2335 * areas. This is because a future no-page fault on this VMA
2336 * could insert a zeroed page instead of the data existing
2337 * from the time of fork. This would look like data corruption
2338 */
2339 if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER))
Mel Gorman4eb2b1d2009-12-14 17:59:53 -08002340 __unmap_hugepage_range(iter_vma,
Adam Litke75266742008-11-12 13:24:56 -08002341 address, address + huge_page_size(h),
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002342 page);
2343 }
Peter Zijlstra3d48ae42011-05-24 17:12:06 -07002344 mutex_unlock(&mapping->i_mmap_mutex);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002345
2346 return 1;
2347}
2348
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002349/*
2350 * Hugetlb_cow() should be called with page lock of the original hugepage held.
2351 */
David Gibson1e8f8892006-01-06 00:10:44 -08002352static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002353 unsigned long address, pte_t *ptep, pte_t pte,
2354 struct page *pagecache_page)
David Gibson1e8f8892006-01-06 00:10:44 -08002355{
Andi Kleena5516432008-07-23 21:27:41 -07002356 struct hstate *h = hstate_vma(vma);
David Gibson1e8f8892006-01-06 00:10:44 -08002357 struct page *old_page, *new_page;
David Gibson79ac6ba2006-03-22 00:08:51 -08002358 int avoidcopy;
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002359 int outside_reserve = 0;
David Gibson1e8f8892006-01-06 00:10:44 -08002360
2361 old_page = pte_page(pte);
2362
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002363retry_avoidcopy:
David Gibson1e8f8892006-01-06 00:10:44 -08002364 /* If no-one else is actually using this page, avoid the copy
2365 * and just make the page writable */
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002366 avoidcopy = (page_mapcount(old_page) == 1);
David Gibson1e8f8892006-01-06 00:10:44 -08002367 if (avoidcopy) {
Naoya Horiguchi56c9cfb2010-09-10 13:23:04 +09002368 if (PageAnon(old_page))
2369 page_move_anon_rmap(old_page, vma, address);
David Gibson1e8f8892006-01-06 00:10:44 -08002370 set_huge_ptep_writable(vma, address, ptep);
Nick Piggin83c54072007-07-19 01:47:05 -07002371 return 0;
David Gibson1e8f8892006-01-06 00:10:44 -08002372 }
2373
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002374 /*
2375 * If the process that created a MAP_PRIVATE mapping is about to
2376 * perform a COW due to a shared page count, attempt to satisfy
2377 * the allocation without using the existing reserves. The pagecache
2378 * page is used to determine if the reserve at this address was
2379 * consumed or not. If reserves were used, a partial faulted mapping
2380 * at the time of fork() could consume its reserves on COW instead
2381 * of the full address range.
2382 */
Mel Gormanf83a2752009-05-28 14:34:40 -07002383 if (!(vma->vm_flags & VM_MAYSHARE) &&
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002384 is_vma_resv_set(vma, HPAGE_RESV_OWNER) &&
2385 old_page != pagecache_page)
2386 outside_reserve = 1;
2387
David Gibson1e8f8892006-01-06 00:10:44 -08002388 page_cache_get(old_page);
Larry Woodmanb76c8cf2009-12-14 17:59:37 -08002389
2390 /* Drop page_table_lock as buddy allocator may be called */
2391 spin_unlock(&mm->page_table_lock);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002392 new_page = alloc_huge_page(vma, address, outside_reserve);
David Gibson1e8f8892006-01-06 00:10:44 -08002393
Adam Litke2fc39ce2007-11-14 16:59:39 -08002394 if (IS_ERR(new_page)) {
David Gibson1e8f8892006-01-06 00:10:44 -08002395 page_cache_release(old_page);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002396
2397 /*
2398 * If a process owning a MAP_PRIVATE mapping fails to COW,
2399 * it is due to references held by a child and an insufficient
2400 * huge page pool. To guarantee the original mappers
2401 * reliability, unmap the page from child processes. The child
2402 * may get SIGKILLed if it later faults.
2403 */
2404 if (outside_reserve) {
2405 BUG_ON(huge_pte_none(pte));
2406 if (unmap_ref_private(mm, vma, old_page, address)) {
2407 BUG_ON(page_count(old_page) != 1);
2408 BUG_ON(huge_pte_none(pte));
Larry Woodmanb76c8cf2009-12-14 17:59:37 -08002409 spin_lock(&mm->page_table_lock);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002410 goto retry_avoidcopy;
2411 }
2412 WARN_ON_ONCE(1);
2413 }
2414
Larry Woodmanb76c8cf2009-12-14 17:59:37 -08002415 /* Caller expects lock to be held */
2416 spin_lock(&mm->page_table_lock);
Adam Litke2fc39ce2007-11-14 16:59:39 -08002417 return -PTR_ERR(new_page);
David Gibson1e8f8892006-01-06 00:10:44 -08002418 }
2419
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002420 /*
2421 * When the original hugepage is shared one, it does not have
2422 * anon_vma prepared.
2423 */
Dean Nelson44e2aa92010-10-26 14:22:08 -07002424 if (unlikely(anon_vma_prepare(vma))) {
Hillf Dantonea4039a2011-11-15 14:36:12 -08002425 page_cache_release(new_page);
2426 page_cache_release(old_page);
Dean Nelson44e2aa92010-10-26 14:22:08 -07002427 /* Caller expects lock to be held */
2428 spin_lock(&mm->page_table_lock);
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002429 return VM_FAULT_OOM;
Dean Nelson44e2aa92010-10-26 14:22:08 -07002430 }
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002431
Andrea Arcangeli47ad8472011-01-13 15:46:47 -08002432 copy_user_huge_page(new_page, old_page, address, vma,
2433 pages_per_huge_page(h));
Nick Piggin0ed361d2008-02-04 22:29:34 -08002434 __SetPageUptodate(new_page);
David Gibson1e8f8892006-01-06 00:10:44 -08002435
Larry Woodmanb76c8cf2009-12-14 17:59:37 -08002436 /*
2437 * Retake the page_table_lock to check for racing updates
2438 * before the page tables are altered
2439 */
2440 spin_lock(&mm->page_table_lock);
Andi Kleena5516432008-07-23 21:27:41 -07002441 ptep = huge_pte_offset(mm, address & huge_page_mask(h));
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002442 if (likely(pte_same(huge_ptep_get(ptep), pte))) {
David Gibson1e8f8892006-01-06 00:10:44 -08002443 /* Break COW */
Doug Doan3edd4fc2010-08-09 17:18:30 -07002444 mmu_notifier_invalidate_range_start(mm,
2445 address & huge_page_mask(h),
2446 (address & huge_page_mask(h)) + huge_page_size(h));
Gerald Schaefer8fe627e2008-04-28 02:13:28 -07002447 huge_ptep_clear_flush(vma, address, ptep);
David Gibson1e8f8892006-01-06 00:10:44 -08002448 set_huge_pte_at(mm, address, ptep,
2449 make_huge_pte(vma, new_page, 1));
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002450 page_remove_rmap(old_page);
Naoya Horiguchicd67f0d2010-09-10 13:23:04 +09002451 hugepage_add_new_anon_rmap(new_page, vma, address);
David Gibson1e8f8892006-01-06 00:10:44 -08002452 /* Make the old page be freed below */
2453 new_page = old_page;
Doug Doan3edd4fc2010-08-09 17:18:30 -07002454 mmu_notifier_invalidate_range_end(mm,
2455 address & huge_page_mask(h),
2456 (address & huge_page_mask(h)) + huge_page_size(h));
David Gibson1e8f8892006-01-06 00:10:44 -08002457 }
2458 page_cache_release(new_page);
2459 page_cache_release(old_page);
Nick Piggin83c54072007-07-19 01:47:05 -07002460 return 0;
David Gibson1e8f8892006-01-06 00:10:44 -08002461}
2462
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002463/* Return the pagecache page at a given address within a VMA */
Andi Kleena5516432008-07-23 21:27:41 -07002464static struct page *hugetlbfs_pagecache_page(struct hstate *h,
2465 struct vm_area_struct *vma, unsigned long address)
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002466{
2467 struct address_space *mapping;
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -07002468 pgoff_t idx;
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002469
2470 mapping = vma->vm_file->f_mapping;
Andi Kleena5516432008-07-23 21:27:41 -07002471 idx = vma_hugecache_offset(h, vma, address);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002472
2473 return find_lock_page(mapping, idx);
2474}
2475
Hugh Dickins3ae77f42009-09-21 17:03:33 -07002476/*
2477 * Return whether there is a pagecache page to back given address within VMA.
2478 * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page.
2479 */
2480static bool hugetlbfs_pagecache_present(struct hstate *h,
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002481 struct vm_area_struct *vma, unsigned long address)
2482{
2483 struct address_space *mapping;
2484 pgoff_t idx;
2485 struct page *page;
2486
2487 mapping = vma->vm_file->f_mapping;
2488 idx = vma_hugecache_offset(h, vma, address);
2489
2490 page = find_get_page(mapping, idx);
2491 if (page)
2492 put_page(page);
2493 return page != NULL;
2494}
2495
Robert P. J. Daya1ed3dd2007-07-17 04:03:33 -07002496static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
Hugh Dickins788c7df2009-06-23 13:49:05 +01002497 unsigned long address, pte_t *ptep, unsigned int flags)
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01002498{
Andi Kleena5516432008-07-23 21:27:41 -07002499 struct hstate *h = hstate_vma(vma);
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01002500 int ret = VM_FAULT_SIGBUS;
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -07002501 pgoff_t idx;
Adam Litke4c887262005-10-29 18:16:46 -07002502 unsigned long size;
Adam Litke4c887262005-10-29 18:16:46 -07002503 struct page *page;
2504 struct address_space *mapping;
David Gibson1e8f8892006-01-06 00:10:44 -08002505 pte_t new_pte;
Adam Litke4c887262005-10-29 18:16:46 -07002506
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002507 /*
2508 * Currently, we are forced to kill the process in the event the
2509 * original mapper has unmapped pages from the child due to a failed
Lucas De Marchi25985ed2011-03-30 22:57:33 -03002510 * COW. Warn that such a situation has occurred as it may not be obvious
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002511 */
2512 if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) {
2513 printk(KERN_WARNING
2514 "PID %d killed due to inadequate hugepage pool\n",
2515 current->pid);
2516 return ret;
2517 }
2518
Adam Litke4c887262005-10-29 18:16:46 -07002519 mapping = vma->vm_file->f_mapping;
Andi Kleena5516432008-07-23 21:27:41 -07002520 idx = vma_hugecache_offset(h, vma, address);
Adam Litke4c887262005-10-29 18:16:46 -07002521
2522 /*
2523 * Use page lock to guard against racing truncation
2524 * before we get page_table_lock.
2525 */
Christoph Lameter6bda6662006-01-06 00:10:49 -08002526retry:
2527 page = find_lock_page(mapping, idx);
2528 if (!page) {
Andi Kleena5516432008-07-23 21:27:41 -07002529 size = i_size_read(mapping->host) >> huge_page_shift(h);
Hugh Dickinsebed4bf2006-10-28 10:38:43 -07002530 if (idx >= size)
2531 goto out;
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002532 page = alloc_huge_page(vma, address, 0);
Adam Litke2fc39ce2007-11-14 16:59:39 -08002533 if (IS_ERR(page)) {
2534 ret = -PTR_ERR(page);
Christoph Lameter6bda6662006-01-06 00:10:49 -08002535 goto out;
2536 }
Andrea Arcangeli47ad8472011-01-13 15:46:47 -08002537 clear_huge_page(page, address, pages_per_huge_page(h));
Nick Piggin0ed361d2008-02-04 22:29:34 -08002538 __SetPageUptodate(page);
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01002539
Mel Gormanf83a2752009-05-28 14:34:40 -07002540 if (vma->vm_flags & VM_MAYSHARE) {
Christoph Lameter6bda6662006-01-06 00:10:49 -08002541 int err;
Ken Chen45c682a2007-11-14 16:59:44 -08002542 struct inode *inode = mapping->host;
Christoph Lameter6bda6662006-01-06 00:10:49 -08002543
2544 err = add_to_page_cache(page, mapping, idx, GFP_KERNEL);
2545 if (err) {
2546 put_page(page);
Christoph Lameter6bda6662006-01-06 00:10:49 -08002547 if (err == -EEXIST)
2548 goto retry;
2549 goto out;
2550 }
Ken Chen45c682a2007-11-14 16:59:44 -08002551
2552 spin_lock(&inode->i_lock);
Andi Kleena5516432008-07-23 21:27:41 -07002553 inode->i_blocks += blocks_per_huge_page(h);
Ken Chen45c682a2007-11-14 16:59:44 -08002554 spin_unlock(&inode->i_lock);
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002555 page_dup_rmap(page);
Mel Gorman23be7462010-04-23 13:17:56 -04002556 } else {
Christoph Lameter6bda6662006-01-06 00:10:49 -08002557 lock_page(page);
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002558 if (unlikely(anon_vma_prepare(vma))) {
2559 ret = VM_FAULT_OOM;
2560 goto backout_unlocked;
2561 }
2562 hugepage_add_new_anon_rmap(page, vma, address);
Mel Gorman23be7462010-04-23 13:17:56 -04002563 }
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002564 } else {
Naoya Horiguchi998b4382010-09-08 10:19:32 +09002565 /*
2566 * If memory error occurs between mmap() and fault, some process
2567 * don't have hwpoisoned swap entry for errored virtual address.
2568 * So we need to block hugepage fault by PG_hwpoison bit check.
2569 */
2570 if (unlikely(PageHWPoison(page))) {
Chris Forbes32f84522011-07-25 17:12:14 -07002571 ret = VM_FAULT_HWPOISON |
Andi Kleenaa50d3a2010-10-06 21:45:00 +02002572 VM_FAULT_SET_HINDEX(h - hstates);
Naoya Horiguchi998b4382010-09-08 10:19:32 +09002573 goto backout_unlocked;
2574 }
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002575 page_dup_rmap(page);
Christoph Lameter6bda6662006-01-06 00:10:49 -08002576 }
David Gibson1e8f8892006-01-06 00:10:44 -08002577
Andy Whitcroft57303d82008-08-12 15:08:47 -07002578 /*
2579 * If we are going to COW a private mapping later, we examine the
2580 * pending reservations for this page now. This will ensure that
2581 * any allocations necessary to record that reservation occur outside
2582 * the spinlock.
2583 */
Hugh Dickins788c7df2009-06-23 13:49:05 +01002584 if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED))
Andy Whitcroft2b267362008-08-12 15:08:49 -07002585 if (vma_needs_reservation(h, vma, address) < 0) {
2586 ret = VM_FAULT_OOM;
2587 goto backout_unlocked;
2588 }
Andy Whitcroft57303d82008-08-12 15:08:47 -07002589
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01002590 spin_lock(&mm->page_table_lock);
Andi Kleena5516432008-07-23 21:27:41 -07002591 size = i_size_read(mapping->host) >> huge_page_shift(h);
Adam Litke4c887262005-10-29 18:16:46 -07002592 if (idx >= size)
2593 goto backout;
2594
Nick Piggin83c54072007-07-19 01:47:05 -07002595 ret = 0;
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002596 if (!huge_pte_none(huge_ptep_get(ptep)))
Adam Litke4c887262005-10-29 18:16:46 -07002597 goto backout;
2598
David Gibson1e8f8892006-01-06 00:10:44 -08002599 new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE)
2600 && (vma->vm_flags & VM_SHARED)));
2601 set_huge_pte_at(mm, address, ptep, new_pte);
2602
Hugh Dickins788c7df2009-06-23 13:49:05 +01002603 if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
David Gibson1e8f8892006-01-06 00:10:44 -08002604 /* Optimization, do the COW without a second fault */
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002605 ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page);
David Gibson1e8f8892006-01-06 00:10:44 -08002606 }
2607
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01002608 spin_unlock(&mm->page_table_lock);
Adam Litke4c887262005-10-29 18:16:46 -07002609 unlock_page(page);
2610out:
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01002611 return ret;
Adam Litke4c887262005-10-29 18:16:46 -07002612
2613backout:
2614 spin_unlock(&mm->page_table_lock);
Andy Whitcroft2b267362008-08-12 15:08:49 -07002615backout_unlocked:
Adam Litke4c887262005-10-29 18:16:46 -07002616 unlock_page(page);
2617 put_page(page);
2618 goto out;
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01002619}
2620
Adam Litke86e52162006-01-06 00:10:43 -08002621int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
Hugh Dickins788c7df2009-06-23 13:49:05 +01002622 unsigned long address, unsigned int flags)
Adam Litke86e52162006-01-06 00:10:43 -08002623{
2624 pte_t *ptep;
2625 pte_t entry;
David Gibson1e8f8892006-01-06 00:10:44 -08002626 int ret;
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002627 struct page *page = NULL;
Andy Whitcroft57303d82008-08-12 15:08:47 -07002628 struct page *pagecache_page = NULL;
David Gibson3935baa2006-03-22 00:08:53 -08002629 static DEFINE_MUTEX(hugetlb_instantiation_mutex);
Andi Kleena5516432008-07-23 21:27:41 -07002630 struct hstate *h = hstate_vma(vma);
Adam Litke86e52162006-01-06 00:10:43 -08002631
Naoya Horiguchifd6a03ed2010-05-28 09:29:21 +09002632 ptep = huge_pte_offset(mm, address);
2633 if (ptep) {
2634 entry = huge_ptep_get(ptep);
Naoya Horiguchi290408d2010-09-08 10:19:35 +09002635 if (unlikely(is_hugetlb_entry_migration(entry))) {
2636 migration_entry_wait(mm, (pmd_t *)ptep, address);
2637 return 0;
2638 } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry)))
Chris Forbes32f84522011-07-25 17:12:14 -07002639 return VM_FAULT_HWPOISON_LARGE |
Andi Kleenaa50d3a2010-10-06 21:45:00 +02002640 VM_FAULT_SET_HINDEX(h - hstates);
Naoya Horiguchifd6a03ed2010-05-28 09:29:21 +09002641 }
2642
Andi Kleena5516432008-07-23 21:27:41 -07002643 ptep = huge_pte_alloc(mm, address, huge_page_size(h));
Adam Litke86e52162006-01-06 00:10:43 -08002644 if (!ptep)
2645 return VM_FAULT_OOM;
2646
David Gibson3935baa2006-03-22 00:08:53 -08002647 /*
2648 * Serialize hugepage allocation and instantiation, so that we don't
2649 * get spurious allocation failures if two CPUs race to instantiate
2650 * the same page in the page cache.
2651 */
2652 mutex_lock(&hugetlb_instantiation_mutex);
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002653 entry = huge_ptep_get(ptep);
2654 if (huge_pte_none(entry)) {
Hugh Dickins788c7df2009-06-23 13:49:05 +01002655 ret = hugetlb_no_page(mm, vma, address, ptep, flags);
David Gibsonb4d1d992008-10-15 22:01:11 -07002656 goto out_mutex;
David Gibson3935baa2006-03-22 00:08:53 -08002657 }
Adam Litke86e52162006-01-06 00:10:43 -08002658
Nick Piggin83c54072007-07-19 01:47:05 -07002659 ret = 0;
David Gibson1e8f8892006-01-06 00:10:44 -08002660
Andy Whitcroft57303d82008-08-12 15:08:47 -07002661 /*
2662 * If we are going to COW the mapping later, we examine the pending
2663 * reservations for this page now. This will ensure that any
2664 * allocations necessary to record that reservation occur outside the
2665 * spinlock. For private mappings, we also lookup the pagecache
2666 * page now as it is used to determine if a reservation has been
2667 * consumed.
2668 */
Hugh Dickins788c7df2009-06-23 13:49:05 +01002669 if ((flags & FAULT_FLAG_WRITE) && !pte_write(entry)) {
Andy Whitcroft2b267362008-08-12 15:08:49 -07002670 if (vma_needs_reservation(h, vma, address) < 0) {
2671 ret = VM_FAULT_OOM;
David Gibsonb4d1d992008-10-15 22:01:11 -07002672 goto out_mutex;
Andy Whitcroft2b267362008-08-12 15:08:49 -07002673 }
Andy Whitcroft57303d82008-08-12 15:08:47 -07002674
Mel Gormanf83a2752009-05-28 14:34:40 -07002675 if (!(vma->vm_flags & VM_MAYSHARE))
Andy Whitcroft57303d82008-08-12 15:08:47 -07002676 pagecache_page = hugetlbfs_pagecache_page(h,
2677 vma, address);
2678 }
2679
Naoya Horiguchi56c9cfb2010-09-10 13:23:04 +09002680 /*
2681 * hugetlb_cow() requires page locks of pte_page(entry) and
2682 * pagecache_page, so here we need take the former one
2683 * when page != pagecache_page or !pagecache_page.
2684 * Note that locking order is always pagecache_page -> page,
2685 * so no worry about deadlock.
2686 */
2687 page = pte_page(entry);
2688 if (page != pagecache_page)
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002689 lock_page(page);
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002690
David Gibson1e8f8892006-01-06 00:10:44 -08002691 spin_lock(&mm->page_table_lock);
2692 /* Check for a racing update before calling hugetlb_cow */
David Gibsonb4d1d992008-10-15 22:01:11 -07002693 if (unlikely(!pte_same(entry, huge_ptep_get(ptep))))
2694 goto out_page_table_lock;
2695
2696
Hugh Dickins788c7df2009-06-23 13:49:05 +01002697 if (flags & FAULT_FLAG_WRITE) {
David Gibsonb4d1d992008-10-15 22:01:11 -07002698 if (!pte_write(entry)) {
Andy Whitcroft57303d82008-08-12 15:08:47 -07002699 ret = hugetlb_cow(mm, vma, address, ptep, entry,
2700 pagecache_page);
David Gibsonb4d1d992008-10-15 22:01:11 -07002701 goto out_page_table_lock;
2702 }
2703 entry = pte_mkdirty(entry);
2704 }
2705 entry = pte_mkyoung(entry);
Hugh Dickins788c7df2009-06-23 13:49:05 +01002706 if (huge_ptep_set_access_flags(vma, address, ptep, entry,
2707 flags & FAULT_FLAG_WRITE))
Russell King4b3073e2009-12-18 16:40:18 +00002708 update_mmu_cache(vma, address, ptep);
David Gibsonb4d1d992008-10-15 22:01:11 -07002709
2710out_page_table_lock:
David Gibson1e8f8892006-01-06 00:10:44 -08002711 spin_unlock(&mm->page_table_lock);
Andy Whitcroft57303d82008-08-12 15:08:47 -07002712
2713 if (pagecache_page) {
2714 unlock_page(pagecache_page);
2715 put_page(pagecache_page);
2716 }
Dean Nelson1f64d692010-12-02 14:31:12 -08002717 if (page != pagecache_page)
2718 unlock_page(page);
Andy Whitcroft57303d82008-08-12 15:08:47 -07002719
David Gibsonb4d1d992008-10-15 22:01:11 -07002720out_mutex:
David Gibson3935baa2006-03-22 00:08:53 -08002721 mutex_unlock(&hugetlb_instantiation_mutex);
David Gibson1e8f8892006-01-06 00:10:44 -08002722
2723 return ret;
Adam Litke86e52162006-01-06 00:10:43 -08002724}
2725
Andi Kleenceb86872008-07-23 21:27:50 -07002726/* Can be overriden by architectures */
2727__attribute__((weak)) struct page *
2728follow_huge_pud(struct mm_struct *mm, unsigned long address,
2729 pud_t *pud, int write)
2730{
2731 BUG();
2732 return NULL;
2733}
2734
David Gibson63551ae2005-06-21 17:14:44 -07002735int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
2736 struct page **pages, struct vm_area_struct **vmas,
Adam Litke5b23dbe2007-11-14 16:59:33 -08002737 unsigned long *position, int *length, int i,
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002738 unsigned int flags)
David Gibson63551ae2005-06-21 17:14:44 -07002739{
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002740 unsigned long pfn_offset;
2741 unsigned long vaddr = *position;
David Gibson63551ae2005-06-21 17:14:44 -07002742 int remainder = *length;
Andi Kleena5516432008-07-23 21:27:41 -07002743 struct hstate *h = hstate_vma(vma);
David Gibson63551ae2005-06-21 17:14:44 -07002744
Hugh Dickins1c598272005-10-19 21:23:43 -07002745 spin_lock(&mm->page_table_lock);
David Gibson63551ae2005-06-21 17:14:44 -07002746 while (vaddr < vma->vm_end && remainder) {
Adam Litke4c887262005-10-29 18:16:46 -07002747 pte_t *pte;
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002748 int absent;
Adam Litke4c887262005-10-29 18:16:46 -07002749 struct page *page;
2750
2751 /*
2752 * Some archs (sparc64, sh*) have multiple pte_ts to
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002753 * each hugepage. We have to make sure we get the
Adam Litke4c887262005-10-29 18:16:46 -07002754 * first, for the page indexing below to work.
2755 */
Andi Kleena5516432008-07-23 21:27:41 -07002756 pte = huge_pte_offset(mm, vaddr & huge_page_mask(h));
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002757 absent = !pte || huge_pte_none(huge_ptep_get(pte));
Adam Litke4c887262005-10-29 18:16:46 -07002758
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002759 /*
2760 * When coredumping, it suits get_dump_page if we just return
Hugh Dickins3ae77f42009-09-21 17:03:33 -07002761 * an error where there's an empty slot with no huge pagecache
2762 * to back it. This way, we avoid allocating a hugepage, and
2763 * the sparse dumpfile avoids allocating disk blocks, but its
2764 * huge holes still show up with zeroes where they need to be.
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002765 */
Hugh Dickins3ae77f42009-09-21 17:03:33 -07002766 if (absent && (flags & FOLL_DUMP) &&
2767 !hugetlbfs_pagecache_present(h, vma, vaddr)) {
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002768 remainder = 0;
2769 break;
2770 }
2771
2772 if (absent ||
2773 ((flags & FOLL_WRITE) && !pte_write(huge_ptep_get(pte)))) {
Adam Litke4c887262005-10-29 18:16:46 -07002774 int ret;
2775
2776 spin_unlock(&mm->page_table_lock);
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002777 ret = hugetlb_fault(mm, vma, vaddr,
2778 (flags & FOLL_WRITE) ? FAULT_FLAG_WRITE : 0);
Adam Litke4c887262005-10-29 18:16:46 -07002779 spin_lock(&mm->page_table_lock);
Adam Litkea89182c2007-08-22 14:01:51 -07002780 if (!(ret & VM_FAULT_ERROR))
Adam Litke4c887262005-10-29 18:16:46 -07002781 continue;
2782
2783 remainder = 0;
Adam Litke4c887262005-10-29 18:16:46 -07002784 break;
2785 }
David Gibson63551ae2005-06-21 17:14:44 -07002786
Andi Kleena5516432008-07-23 21:27:41 -07002787 pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT;
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002788 page = pte_page(huge_ptep_get(pte));
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002789same_page:
Chen, Kenneth Wd6692182006-03-31 02:29:57 -08002790 if (pages) {
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002791 pages[i] = mem_map_offset(page, pfn_offset);
KOSAKI Motohiro4b2e38a2008-10-18 20:27:10 -07002792 get_page(pages[i]);
Chen, Kenneth Wd6692182006-03-31 02:29:57 -08002793 }
David Gibson63551ae2005-06-21 17:14:44 -07002794
2795 if (vmas)
2796 vmas[i] = vma;
2797
2798 vaddr += PAGE_SIZE;
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002799 ++pfn_offset;
David Gibson63551ae2005-06-21 17:14:44 -07002800 --remainder;
2801 ++i;
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002802 if (vaddr < vma->vm_end && remainder &&
Andi Kleena5516432008-07-23 21:27:41 -07002803 pfn_offset < pages_per_huge_page(h)) {
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002804 /*
2805 * We use pfn_offset to avoid touching the pageframes
2806 * of this compound page.
2807 */
2808 goto same_page;
2809 }
David Gibson63551ae2005-06-21 17:14:44 -07002810 }
Hugh Dickins1c598272005-10-19 21:23:43 -07002811 spin_unlock(&mm->page_table_lock);
David Gibson63551ae2005-06-21 17:14:44 -07002812 *length = remainder;
2813 *position = vaddr;
2814
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002815 return i ? i : -EFAULT;
David Gibson63551ae2005-06-21 17:14:44 -07002816}
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002817
2818void hugetlb_change_protection(struct vm_area_struct *vma,
2819 unsigned long address, unsigned long end, pgprot_t newprot)
2820{
2821 struct mm_struct *mm = vma->vm_mm;
2822 unsigned long start = address;
2823 pte_t *ptep;
2824 pte_t pte;
Andi Kleena5516432008-07-23 21:27:41 -07002825 struct hstate *h = hstate_vma(vma);
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002826
2827 BUG_ON(address >= end);
2828 flush_cache_range(vma, address, end);
2829
Peter Zijlstra3d48ae42011-05-24 17:12:06 -07002830 mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex);
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002831 spin_lock(&mm->page_table_lock);
Andi Kleena5516432008-07-23 21:27:41 -07002832 for (; address < end; address += huge_page_size(h)) {
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002833 ptep = huge_pte_offset(mm, address);
2834 if (!ptep)
2835 continue;
Chen, Kenneth W39dde652006-12-06 20:32:03 -08002836 if (huge_pmd_unshare(mm, &address, ptep))
2837 continue;
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002838 if (!huge_pte_none(huge_ptep_get(ptep))) {
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002839 pte = huge_ptep_get_and_clear(mm, address, ptep);
2840 pte = pte_mkhuge(pte_modify(pte, newprot));
2841 set_huge_pte_at(mm, address, ptep, pte);
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002842 }
2843 }
2844 spin_unlock(&mm->page_table_lock);
Peter Zijlstra3d48ae42011-05-24 17:12:06 -07002845 mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002846
2847 flush_tlb_range(vma, start, end);
2848}
2849
Mel Gormana1e78772008-07-23 21:27:23 -07002850int hugetlb_reserve_pages(struct inode *inode,
2851 long from, long to,
Mel Gorman5a6fe122009-02-10 14:02:27 +00002852 struct vm_area_struct *vma,
KOSAKI Motohiroca16d142011-05-26 19:16:19 +09002853 vm_flags_t vm_flags)
Adam Litkee4e574b2007-10-16 01:26:19 -07002854{
Mel Gorman17c9d122009-02-11 16:34:16 +00002855 long ret, chg;
Andi Kleena5516432008-07-23 21:27:41 -07002856 struct hstate *h = hstate_inode(inode);
Adam Litkee4e574b2007-10-16 01:26:19 -07002857
Mel Gormana1e78772008-07-23 21:27:23 -07002858 /*
Mel Gorman17c9d122009-02-11 16:34:16 +00002859 * Only apply hugepage reservation if asked. At fault time, an
2860 * attempt will be made for VM_NORESERVE to allocate a page
2861 * and filesystem quota without using reserves
2862 */
KOSAKI Motohiroca16d142011-05-26 19:16:19 +09002863 if (vm_flags & VM_NORESERVE)
Mel Gorman17c9d122009-02-11 16:34:16 +00002864 return 0;
2865
2866 /*
Mel Gormana1e78772008-07-23 21:27:23 -07002867 * Shared mappings base their reservation on the number of pages that
2868 * are already allocated on behalf of the file. Private mappings need
2869 * to reserve the full area even if read-only as mprotect() may be
2870 * called to make the mapping read-write. Assume !vma is a shm mapping
2871 */
Mel Gormanf83a2752009-05-28 14:34:40 -07002872 if (!vma || vma->vm_flags & VM_MAYSHARE)
Mel Gormana1e78772008-07-23 21:27:23 -07002873 chg = region_chg(&inode->i_mapping->private_list, from, to);
Mel Gorman5a6fe122009-02-10 14:02:27 +00002874 else {
2875 struct resv_map *resv_map = resv_map_alloc();
Mel Gorman5a6fe122009-02-10 14:02:27 +00002876 if (!resv_map)
2877 return -ENOMEM;
2878
Mel Gorman17c9d122009-02-11 16:34:16 +00002879 chg = to - from;
2880
Mel Gorman5a6fe122009-02-10 14:02:27 +00002881 set_vma_resv_map(vma, resv_map);
2882 set_vma_resv_flags(vma, HPAGE_RESV_OWNER);
2883 }
2884
Mel Gorman17c9d122009-02-11 16:34:16 +00002885 if (chg < 0)
2886 return chg;
2887
2888 /* There must be enough filesystem quota for the mapping */
2889 if (hugetlb_get_quota(inode->i_mapping, chg))
2890 return -ENOSPC;
2891
2892 /*
2893 * Check enough hugepages are available for the reservation.
2894 * Hand back the quota if there are not
2895 */
2896 ret = hugetlb_acct_memory(h, chg);
2897 if (ret < 0) {
2898 hugetlb_put_quota(inode->i_mapping, chg);
2899 return ret;
2900 }
2901
2902 /*
2903 * Account for the reservations made. Shared mappings record regions
2904 * that have reservations as they are shared by multiple VMAs.
2905 * When the last VMA disappears, the region map says how much
2906 * the reservation was and the page cache tells how much of
2907 * the reservation was consumed. Private mappings are per-VMA and
2908 * only the consumed reservations are tracked. When the VMA
2909 * disappears, the original reservation is the VMA size and the
2910 * consumed reservations are stored in the map. Hence, nothing
2911 * else has to be done for private mappings here
2912 */
Mel Gormanf83a2752009-05-28 14:34:40 -07002913 if (!vma || vma->vm_flags & VM_MAYSHARE)
Mel Gorman17c9d122009-02-11 16:34:16 +00002914 region_add(&inode->i_mapping->private_list, from, to);
Chen, Kenneth Wa43a8c32006-06-23 02:03:15 -07002915 return 0;
2916}
2917
2918void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed)
2919{
Andi Kleena5516432008-07-23 21:27:41 -07002920 struct hstate *h = hstate_inode(inode);
Chen, Kenneth Wa43a8c32006-06-23 02:03:15 -07002921 long chg = region_truncate(&inode->i_mapping->private_list, offset);
Ken Chen45c682a2007-11-14 16:59:44 -08002922
2923 spin_lock(&inode->i_lock);
Eric Sandeene4c6f8b2009-07-29 15:02:16 -07002924 inode->i_blocks -= (blocks_per_huge_page(h) * freed);
Ken Chen45c682a2007-11-14 16:59:44 -08002925 spin_unlock(&inode->i_lock);
2926
Adam Litke90d8b7e2007-11-14 16:59:42 -08002927 hugetlb_put_quota(inode->i_mapping, (chg - freed));
Andi Kleena5516432008-07-23 21:27:41 -07002928 hugetlb_acct_memory(h, -(chg - freed));
Chen, Kenneth Wa43a8c32006-06-23 02:03:15 -07002929}
Naoya Horiguchi93f70f92010-05-28 09:29:20 +09002930
Andi Kleend5bd9102010-09-27 09:00:12 +02002931#ifdef CONFIG_MEMORY_FAILURE
2932
Naoya Horiguchi6de2b1a2010-09-08 10:19:36 +09002933/* Should be called in hugetlb_lock */
2934static int is_hugepage_on_freelist(struct page *hpage)
2935{
2936 struct page *page;
2937 struct page *tmp;
2938 struct hstate *h = page_hstate(hpage);
2939 int nid = page_to_nid(hpage);
2940
2941 list_for_each_entry_safe(page, tmp, &h->hugepage_freelists[nid], lru)
2942 if (page == hpage)
2943 return 1;
2944 return 0;
2945}
2946
Naoya Horiguchi93f70f92010-05-28 09:29:20 +09002947/*
2948 * This function is called from memory failure code.
2949 * Assume the caller holds page lock of the head page.
2950 */
Naoya Horiguchi6de2b1a2010-09-08 10:19:36 +09002951int dequeue_hwpoisoned_huge_page(struct page *hpage)
Naoya Horiguchi93f70f92010-05-28 09:29:20 +09002952{
2953 struct hstate *h = page_hstate(hpage);
2954 int nid = page_to_nid(hpage);
Naoya Horiguchi6de2b1a2010-09-08 10:19:36 +09002955 int ret = -EBUSY;
Naoya Horiguchi93f70f92010-05-28 09:29:20 +09002956
2957 spin_lock(&hugetlb_lock);
Naoya Horiguchi6de2b1a2010-09-08 10:19:36 +09002958 if (is_hugepage_on_freelist(hpage)) {
2959 list_del(&hpage->lru);
Naoya Horiguchi8c6c2ec2010-09-08 10:19:38 +09002960 set_page_refcounted(hpage);
Naoya Horiguchi6de2b1a2010-09-08 10:19:36 +09002961 h->free_huge_pages--;
2962 h->free_huge_pages_node[nid]--;
2963 ret = 0;
2964 }
Naoya Horiguchi93f70f92010-05-28 09:29:20 +09002965 spin_unlock(&hugetlb_lock);
Naoya Horiguchi6de2b1a2010-09-08 10:19:36 +09002966 return ret;
Naoya Horiguchi93f70f92010-05-28 09:29:20 +09002967}
Naoya Horiguchi6de2b1a2010-09-08 10:19:36 +09002968#endif