blob: c03273807182dde1d9dd2e905c0db11a6dfe2441 [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 Horiguchifd6a03e2010-05-28 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>
Adrian Bunk78a34ae2008-07-28 15:46:30 -070027#include <asm/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 *
65 * down_write(&mm->mmap_sem);
66 * or
67 * 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
149 /* We overlap with this area, if it extends futher than
150 * 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
Andy Whitcroft69d177c2008-11-06 12:53:26 -0800397static void clear_gigantic_page(struct page *page,
398 unsigned long addr, unsigned long sz)
399{
400 int i;
401 struct page *p = page;
402
403 might_sleep();
404 for (i = 0; i < sz/PAGE_SIZE; i++, p = mem_map_next(p, page, i)) {
405 cond_resched();
406 clear_user_highpage(p, addr + i * PAGE_SIZE);
407 }
408}
Andi Kleena5516432008-07-23 21:27:41 -0700409static void clear_huge_page(struct page *page,
410 unsigned long addr, unsigned long sz)
David Gibson79ac6ba2006-03-22 00:08:51 -0800411{
412 int i;
413
Andrea Arcangeli74dbdd22010-01-08 14:43:05 -0800414 if (unlikely(sz/PAGE_SIZE > MAX_ORDER_NR_PAGES)) {
Hannes Ederebdd4ae2009-01-06 14:39:58 -0800415 clear_gigantic_page(page, addr, sz);
416 return;
417 }
Andy Whitcroft69d177c2008-11-06 12:53:26 -0800418
David Gibson79ac6ba2006-03-22 00:08:51 -0800419 might_sleep();
Andi Kleena5516432008-07-23 21:27:41 -0700420 for (i = 0; i < sz/PAGE_SIZE; i++) {
David Gibson79ac6ba2006-03-22 00:08:51 -0800421 cond_resched();
Ralf Baechle281e0e32007-10-01 01:20:10 -0700422 clear_user_highpage(page + i, addr + i * PAGE_SIZE);
David Gibson79ac6ba2006-03-22 00:08:51 -0800423 }
424}
425
Andy Whitcroft69d177c2008-11-06 12:53:26 -0800426static void copy_gigantic_page(struct page *dst, struct page *src,
427 unsigned long addr, struct vm_area_struct *vma)
428{
429 int i;
430 struct hstate *h = hstate_vma(vma);
431 struct page *dst_base = dst;
432 struct page *src_base = src;
433 might_sleep();
434 for (i = 0; i < pages_per_huge_page(h); ) {
435 cond_resched();
436 copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma);
437
438 i++;
439 dst = mem_map_next(dst, dst_base, i);
440 src = mem_map_next(src, src_base, i);
441 }
442}
David Gibson79ac6ba2006-03-22 00:08:51 -0800443static void copy_huge_page(struct page *dst, struct page *src,
Atsushi Nemoto9de455b2006-12-12 17:14:55 +0000444 unsigned long addr, struct vm_area_struct *vma)
David Gibson79ac6ba2006-03-22 00:08:51 -0800445{
446 int i;
Andi Kleena5516432008-07-23 21:27:41 -0700447 struct hstate *h = hstate_vma(vma);
David Gibson79ac6ba2006-03-22 00:08:51 -0800448
Hannes Ederebdd4ae2009-01-06 14:39:58 -0800449 if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) {
450 copy_gigantic_page(dst, src, addr, vma);
451 return;
452 }
Andy Whitcroft69d177c2008-11-06 12:53:26 -0800453
David Gibson79ac6ba2006-03-22 00:08:51 -0800454 might_sleep();
Andi Kleena5516432008-07-23 21:27:41 -0700455 for (i = 0; i < pages_per_huge_page(h); i++) {
David Gibson79ac6ba2006-03-22 00:08:51 -0800456 cond_resched();
Atsushi Nemoto9de455b2006-12-12 17:14:55 +0000457 copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma);
David Gibson79ac6ba2006-03-22 00:08:51 -0800458 }
459}
460
Andi Kleena5516432008-07-23 21:27:41 -0700461static void enqueue_huge_page(struct hstate *h, struct page *page)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462{
463 int nid = page_to_nid(page);
Andi Kleena5516432008-07-23 21:27:41 -0700464 list_add(&page->lru, &h->hugepage_freelists[nid]);
465 h->free_huge_pages++;
466 h->free_huge_pages_node[nid]++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467}
468
Andi Kleena5516432008-07-23 21:27:41 -0700469static struct page *dequeue_huge_page_vma(struct hstate *h,
470 struct vm_area_struct *vma,
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700471 unsigned long address, int avoid_reserve)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472{
Nishanth Aravamudan31a5c6e2007-07-15 23:38:02 -0700473 int nid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 struct page *page = NULL;
Lee Schermerhorn480eccf2007-09-18 22:46:47 -0700475 struct mempolicy *mpol;
Mel Gorman19770b32008-04-28 02:12:18 -0700476 nodemask_t *nodemask;
Miao Xiec0ff7452010-05-24 14:32:08 -0700477 struct zonelist *zonelist;
Mel Gormandd1a2392008-04-28 02:12:17 -0700478 struct zone *zone;
479 struct zoneref *z;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480
Miao Xiec0ff7452010-05-24 14:32:08 -0700481 get_mems_allowed();
482 zonelist = huge_zonelist(vma, address,
483 htlb_alloc_mask, &mpol, &nodemask);
Mel Gormana1e78772008-07-23 21:27:23 -0700484 /*
485 * A child process with MAP_PRIVATE mappings created by their parent
486 * have no page reserves. This check ensures that reservations are
487 * not "stolen". The child may still get SIGKILLed
488 */
Mel Gorman7f09ca52008-07-23 21:27:58 -0700489 if (!vma_has_reserves(vma) &&
Andi Kleena5516432008-07-23 21:27:41 -0700490 h->free_huge_pages - h->resv_huge_pages == 0)
Miao Xiec0ff7452010-05-24 14:32:08 -0700491 goto err;
Mel Gormana1e78772008-07-23 21:27:23 -0700492
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700493 /* If reserves cannot be used, ensure enough pages are in the pool */
Andi Kleena5516432008-07-23 21:27:41 -0700494 if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0)
Miao Xiec0ff7452010-05-24 14:32:08 -0700495 goto err;;
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700496
Mel Gorman19770b32008-04-28 02:12:18 -0700497 for_each_zone_zonelist_nodemask(zone, z, zonelist,
498 MAX_NR_ZONES - 1, nodemask) {
Mel Gorman54a6eb52008-04-28 02:12:16 -0700499 nid = zone_to_nid(zone);
500 if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) &&
Andi Kleena5516432008-07-23 21:27:41 -0700501 !list_empty(&h->hugepage_freelists[nid])) {
502 page = list_entry(h->hugepage_freelists[nid].next,
Andrew Morton3abf7af2007-07-19 01:49:08 -0700503 struct page, lru);
504 list_del(&page->lru);
Andi Kleena5516432008-07-23 21:27:41 -0700505 h->free_huge_pages--;
506 h->free_huge_pages_node[nid]--;
Mel Gorman04f2cbe2008-07-23 21:27:25 -0700507
508 if (!avoid_reserve)
Andi Kleena5516432008-07-23 21:27:41 -0700509 decrement_hugepage_resv_vma(h, vma);
Mel Gormana1e78772008-07-23 21:27:23 -0700510
Ken Chen5ab3ee72007-07-23 18:44:00 -0700511 break;
Andrew Morton3abf7af2007-07-19 01:49:08 -0700512 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 }
Miao Xiec0ff7452010-05-24 14:32:08 -0700514err:
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700515 mpol_cond_put(mpol);
Miao Xiec0ff7452010-05-24 14:32:08 -0700516 put_mems_allowed();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 return page;
518}
519
Andi Kleena5516432008-07-23 21:27:41 -0700520static void update_and_free_page(struct hstate *h, struct page *page)
Adam Litke6af2acb2007-10-16 01:26:16 -0700521{
522 int i;
Andi Kleena5516432008-07-23 21:27:41 -0700523
Andy Whitcroft18229df2008-11-06 12:53:27 -0800524 VM_BUG_ON(h->order >= MAX_ORDER);
525
Andi Kleena5516432008-07-23 21:27:41 -0700526 h->nr_huge_pages--;
527 h->nr_huge_pages_node[page_to_nid(page)]--;
528 for (i = 0; i < pages_per_huge_page(h); i++) {
Adam Litke6af2acb2007-10-16 01:26:16 -0700529 page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced |
530 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved |
531 1 << PG_private | 1<< PG_writeback);
532 }
533 set_compound_page_dtor(page, NULL);
534 set_page_refcounted(page);
Gerald Schaefer7f2e9522008-04-28 02:13:29 -0700535 arch_release_hugepage(page);
Andi Kleena5516432008-07-23 21:27:41 -0700536 __free_pages(page, huge_page_order(h));
Adam Litke6af2acb2007-10-16 01:26:16 -0700537}
538
Andi Kleene5ff2152008-07-23 21:27:42 -0700539struct hstate *size_to_hstate(unsigned long size)
540{
541 struct hstate *h;
542
543 for_each_hstate(h) {
544 if (huge_page_size(h) == size)
545 return h;
546 }
547 return NULL;
548}
549
David Gibson27a85ef2006-03-22 00:08:56 -0800550static void free_huge_page(struct page *page)
551{
Andi Kleena5516432008-07-23 21:27:41 -0700552 /*
553 * Can't pass hstate in here because it is called from the
554 * compound page destructor.
555 */
Andi Kleene5ff2152008-07-23 21:27:42 -0700556 struct hstate *h = page_hstate(page);
Adam Litke7893d1d2007-10-16 01:26:18 -0700557 int nid = page_to_nid(page);
Adam Litkec79fb752007-11-14 16:59:38 -0800558 struct address_space *mapping;
David Gibson27a85ef2006-03-22 00:08:56 -0800559
Adam Litkec79fb752007-11-14 16:59:38 -0800560 mapping = (struct address_space *) page_private(page);
Andy Whitcrofte5df70a2008-02-23 15:23:32 -0800561 set_page_private(page, 0);
Mel Gorman23be7462010-04-23 13:17:56 -0400562 page->mapping = NULL;
Adam Litke7893d1d2007-10-16 01:26:18 -0700563 BUG_ON(page_count(page));
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +0900564 BUG_ON(page_mapcount(page));
David Gibson27a85ef2006-03-22 00:08:56 -0800565 INIT_LIST_HEAD(&page->lru);
566
567 spin_lock(&hugetlb_lock);
Andi Kleenaa888a72008-07-23 21:27:47 -0700568 if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) {
Andi Kleena5516432008-07-23 21:27:41 -0700569 update_and_free_page(h, page);
570 h->surplus_huge_pages--;
571 h->surplus_huge_pages_node[nid]--;
Adam Litke7893d1d2007-10-16 01:26:18 -0700572 } else {
Andi Kleena5516432008-07-23 21:27:41 -0700573 enqueue_huge_page(h, page);
Adam Litke7893d1d2007-10-16 01:26:18 -0700574 }
David Gibson27a85ef2006-03-22 00:08:56 -0800575 spin_unlock(&hugetlb_lock);
Adam Litkec79fb752007-11-14 16:59:38 -0800576 if (mapping)
Adam Litke9a119c02007-11-14 16:59:41 -0800577 hugetlb_put_quota(mapping, 1);
David Gibson27a85ef2006-03-22 00:08:56 -0800578}
579
Andi Kleena5516432008-07-23 21:27:41 -0700580static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
Andi Kleenb7ba30c2008-07-23 21:27:40 -0700581{
582 set_compound_page_dtor(page, free_huge_page);
583 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -0700584 h->nr_huge_pages++;
585 h->nr_huge_pages_node[nid]++;
Andi Kleenb7ba30c2008-07-23 21:27:40 -0700586 spin_unlock(&hugetlb_lock);
587 put_page(page); /* free it into the hugepage allocator */
588}
589
Wu Fengguang20a03072009-06-16 15:32:22 -0700590static void prep_compound_gigantic_page(struct page *page, unsigned long order)
591{
592 int i;
593 int nr_pages = 1 << order;
594 struct page *p = page + 1;
595
596 /* we rely on prep_new_huge_page to set the destructor */
597 set_compound_order(page, order);
598 __SetPageHead(page);
599 for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
600 __SetPageTail(p);
601 p->first_page = page;
602 }
603}
604
605int PageHuge(struct page *page)
606{
607 compound_page_dtor *dtor;
608
609 if (!PageCompound(page))
610 return 0;
611
612 page = compound_head(page);
613 dtor = get_compound_page_dtor(page);
614
615 return dtor == free_huge_page;
616}
617
Naoya Horiguchi43131e12010-05-28 09:29:22 +0900618EXPORT_SYMBOL_GPL(PageHuge);
619
Andi Kleena5516432008-07-23 21:27:41 -0700620static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 struct page *page;
Joe Jinf96efd52007-07-15 23:38:12 -0700623
Andi Kleenaa888a72008-07-23 21:27:47 -0700624 if (h->order >= MAX_ORDER)
625 return NULL;
626
Mel Gorman6484eb32009-06-16 15:31:54 -0700627 page = alloc_pages_exact_node(nid,
Nishanth Aravamudan551883a2008-04-29 00:58:26 -0700628 htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
629 __GFP_REPEAT|__GFP_NOWARN,
Andi Kleena5516432008-07-23 21:27:41 -0700630 huge_page_order(h));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 if (page) {
Gerald Schaefer7f2e9522008-04-28 02:13:29 -0700632 if (arch_prepare_hugepage(page)) {
Gerald Schaefercaff3a22008-08-12 15:08:38 -0700633 __free_pages(page, huge_page_order(h));
Harvey Harrison7b8ee842008-04-28 14:13:19 -0700634 return NULL;
Gerald Schaefer7f2e9522008-04-28 02:13:29 -0700635 }
Andi Kleena5516432008-07-23 21:27:41 -0700636 prep_new_huge_page(h, page, nid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 }
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700638
639 return page;
640}
641
Andi Kleen5ced66c2008-07-23 21:27:45 -0700642/*
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800643 * common helper functions for hstate_next_node_to_{alloc|free}.
644 * We may have allocated or freed a huge page based on a different
645 * nodes_allowed previously, so h->next_node_to_{alloc|free} might
646 * be outside of *nodes_allowed. Ensure that we use an allowed
647 * node for alloc or free.
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800648 */
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800649static int next_node_allowed(int nid, nodemask_t *nodes_allowed)
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800650{
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800651 nid = next_node(nid, *nodes_allowed);
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800652 if (nid == MAX_NUMNODES)
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800653 nid = first_node(*nodes_allowed);
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800654 VM_BUG_ON(nid >= MAX_NUMNODES);
655
656 return nid;
657}
658
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800659static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed)
Andi Kleen5ced66c2008-07-23 21:27:45 -0700660{
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800661 if (!node_isset(nid, *nodes_allowed))
662 nid = next_node_allowed(nid, nodes_allowed);
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800663 return nid;
Andi Kleen5ced66c2008-07-23 21:27:45 -0700664}
665
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800666/*
667 * returns the previously saved node ["this node"] from which to
668 * allocate a persistent huge page for the pool and advance the
669 * next node from which to allocate, handling wrap at end of node
670 * mask.
671 */
672static int hstate_next_node_to_alloc(struct hstate *h,
673 nodemask_t *nodes_allowed)
674{
675 int nid;
676
677 VM_BUG_ON(!nodes_allowed);
678
679 nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed);
680 h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed);
681
682 return nid;
683}
684
685static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed)
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700686{
687 struct page *page;
688 int start_nid;
689 int next_nid;
690 int ret = 0;
691
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800692 start_nid = hstate_next_node_to_alloc(h, nodes_allowed);
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700693 next_nid = start_nid;
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700694
695 do {
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700696 page = alloc_fresh_huge_page_node(h, next_nid);
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800697 if (page) {
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700698 ret = 1;
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800699 break;
700 }
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800701 next_nid = hstate_next_node_to_alloc(h, nodes_allowed);
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800702 } while (next_nid != start_nid);
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700703
Adam Litke3b116302008-04-28 02:13:06 -0700704 if (ret)
705 count_vm_event(HTLB_BUDDY_PGALLOC);
706 else
707 count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
708
Nishanth Aravamudan63b46132007-10-16 01:26:24 -0700709 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710}
711
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700712/*
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800713 * helper for free_pool_huge_page() - return the previously saved
714 * node ["this node"] from which to free a huge page. Advance the
715 * next node id whether or not we find a free huge page to free so
716 * that the next attempt to free addresses the next node.
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700717 */
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800718static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed)
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700719{
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800720 int nid;
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800721
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800722 VM_BUG_ON(!nodes_allowed);
723
724 nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed);
725 h->next_nid_to_free = next_node_allowed(nid, nodes_allowed);
726
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800727 return nid;
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700728}
729
730/*
731 * Free huge page from pool from next node to free.
732 * Attempt to keep persistent huge pages more or less
733 * balanced over allowed nodes.
734 * Called with hugetlb_lock locked.
735 */
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800736static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed,
737 bool acct_surplus)
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700738{
739 int start_nid;
740 int next_nid;
741 int ret = 0;
742
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800743 start_nid = hstate_next_node_to_free(h, nodes_allowed);
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700744 next_nid = start_nid;
745
746 do {
Lee Schermerhorn685f3452009-09-21 17:01:23 -0700747 /*
748 * If we're returning unused surplus pages, only examine
749 * nodes with surplus pages.
750 */
751 if ((!acct_surplus || h->surplus_huge_pages_node[next_nid]) &&
752 !list_empty(&h->hugepage_freelists[next_nid])) {
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700753 struct page *page =
754 list_entry(h->hugepage_freelists[next_nid].next,
755 struct page, lru);
756 list_del(&page->lru);
757 h->free_huge_pages--;
758 h->free_huge_pages_node[next_nid]--;
Lee Schermerhorn685f3452009-09-21 17:01:23 -0700759 if (acct_surplus) {
760 h->surplus_huge_pages--;
761 h->surplus_huge_pages_node[next_nid]--;
762 }
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700763 update_and_free_page(h, page);
764 ret = 1;
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800765 break;
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700766 }
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -0800767 next_nid = hstate_next_node_to_free(h, nodes_allowed);
Lee Schermerhorn9a76db02009-12-14 17:58:15 -0800768 } while (next_nid != start_nid);
Lee Schermerhorne8c5c822009-09-21 17:01:22 -0700769
770 return ret;
771}
772
Andi Kleena5516432008-07-23 21:27:41 -0700773static struct page *alloc_buddy_huge_page(struct hstate *h,
774 struct vm_area_struct *vma, unsigned long address)
Adam Litke7893d1d2007-10-16 01:26:18 -0700775{
776 struct page *page;
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800777 unsigned int nid;
Adam Litke7893d1d2007-10-16 01:26:18 -0700778
Andi Kleenaa888a72008-07-23 21:27:47 -0700779 if (h->order >= MAX_ORDER)
780 return NULL;
781
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800782 /*
783 * Assume we will successfully allocate the surplus page to
784 * prevent racing processes from causing the surplus to exceed
785 * overcommit
786 *
787 * This however introduces a different race, where a process B
788 * tries to grow the static hugepage pool while alloc_pages() is
789 * called by process A. B will only examine the per-node
790 * counters in determining if surplus huge pages can be
791 * converted to normal huge pages in adjust_pool_surplus(). A
792 * won't be able to increment the per-node counter, until the
793 * lock is dropped by B, but B doesn't drop hugetlb_lock until
794 * no more huge pages can be converted from surplus to normal
795 * state (and doesn't try to convert again). Thus, we have a
796 * case where a surplus huge page exists, the pool is grown, and
797 * the surplus huge page still exists after, even though it
798 * should just have been converted to a normal huge page. This
799 * does not leak memory, though, as the hugepage will be freed
800 * once it is out of use. It also does not allow the counters to
801 * go out of whack in adjust_pool_surplus() as we don't modify
802 * the node values until we've gotten the hugepage and only the
803 * per-node value is checked there.
804 */
805 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -0700806 if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) {
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800807 spin_unlock(&hugetlb_lock);
808 return NULL;
809 } else {
Andi Kleena5516432008-07-23 21:27:41 -0700810 h->nr_huge_pages++;
811 h->surplus_huge_pages++;
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800812 }
813 spin_unlock(&hugetlb_lock);
814
Nishanth Aravamudan551883a2008-04-29 00:58:26 -0700815 page = alloc_pages(htlb_alloc_mask|__GFP_COMP|
816 __GFP_REPEAT|__GFP_NOWARN,
Andi Kleena5516432008-07-23 21:27:41 -0700817 huge_page_order(h));
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800818
Gerald Schaefercaff3a22008-08-12 15:08:38 -0700819 if (page && arch_prepare_hugepage(page)) {
820 __free_pages(page, huge_page_order(h));
821 return NULL;
822 }
823
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800824 spin_lock(&hugetlb_lock);
Adam Litke7893d1d2007-10-16 01:26:18 -0700825 if (page) {
Adam Litke2668db92008-03-10 11:43:50 -0700826 /*
827 * This page is now managed by the hugetlb allocator and has
828 * no users -- drop the buddy allocator's reference.
829 */
830 put_page_testzero(page);
831 VM_BUG_ON(page_count(page));
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800832 nid = page_to_nid(page);
Adam Litke7893d1d2007-10-16 01:26:18 -0700833 set_compound_page_dtor(page, free_huge_page);
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800834 /*
835 * We incremented the global counters already
836 */
Andi Kleena5516432008-07-23 21:27:41 -0700837 h->nr_huge_pages_node[nid]++;
838 h->surplus_huge_pages_node[nid]++;
Adam Litke3b116302008-04-28 02:13:06 -0700839 __count_vm_event(HTLB_BUDDY_PGALLOC);
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800840 } else {
Andi Kleena5516432008-07-23 21:27:41 -0700841 h->nr_huge_pages--;
842 h->surplus_huge_pages--;
Adam Litke3b116302008-04-28 02:13:06 -0700843 __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
Adam Litke7893d1d2007-10-16 01:26:18 -0700844 }
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -0800845 spin_unlock(&hugetlb_lock);
Adam Litke7893d1d2007-10-16 01:26:18 -0700846
847 return page;
848}
849
Adam Litkee4e574b2007-10-16 01:26:19 -0700850/*
851 * Increase the hugetlb pool such that it can accomodate a reservation
852 * of size 'delta'.
853 */
Andi Kleena5516432008-07-23 21:27:41 -0700854static int gather_surplus_pages(struct hstate *h, int delta)
Adam Litkee4e574b2007-10-16 01:26:19 -0700855{
856 struct list_head surplus_list;
857 struct page *page, *tmp;
858 int ret, i;
859 int needed, allocated;
860
Andi Kleena5516432008-07-23 21:27:41 -0700861 needed = (h->resv_huge_pages + delta) - h->free_huge_pages;
Adam Litkeac09b3a2008-03-04 14:29:38 -0800862 if (needed <= 0) {
Andi Kleena5516432008-07-23 21:27:41 -0700863 h->resv_huge_pages += delta;
Adam Litkee4e574b2007-10-16 01:26:19 -0700864 return 0;
Adam Litkeac09b3a2008-03-04 14:29:38 -0800865 }
Adam Litkee4e574b2007-10-16 01:26:19 -0700866
867 allocated = 0;
868 INIT_LIST_HEAD(&surplus_list);
869
870 ret = -ENOMEM;
871retry:
872 spin_unlock(&hugetlb_lock);
873 for (i = 0; i < needed; i++) {
Andi Kleena5516432008-07-23 21:27:41 -0700874 page = alloc_buddy_huge_page(h, NULL, 0);
Adam Litkee4e574b2007-10-16 01:26:19 -0700875 if (!page) {
876 /*
877 * We were not able to allocate enough pages to
878 * satisfy the entire reservation so we free what
879 * we've allocated so far.
880 */
881 spin_lock(&hugetlb_lock);
882 needed = 0;
883 goto free;
884 }
885
886 list_add(&page->lru, &surplus_list);
887 }
888 allocated += needed;
889
890 /*
891 * After retaking hugetlb_lock, we need to recalculate 'needed'
892 * because either resv_huge_pages or free_huge_pages may have changed.
893 */
894 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -0700895 needed = (h->resv_huge_pages + delta) -
896 (h->free_huge_pages + allocated);
Adam Litkee4e574b2007-10-16 01:26:19 -0700897 if (needed > 0)
898 goto retry;
899
900 /*
901 * The surplus_list now contains _at_least_ the number of extra pages
902 * needed to accomodate the reservation. Add the appropriate number
903 * of pages to the hugetlb pool and free the extras back to the buddy
Adam Litkeac09b3a2008-03-04 14:29:38 -0800904 * allocator. Commit the entire reservation here to prevent another
905 * process from stealing the pages as they are added to the pool but
906 * before they are reserved.
Adam Litkee4e574b2007-10-16 01:26:19 -0700907 */
908 needed += allocated;
Andi Kleena5516432008-07-23 21:27:41 -0700909 h->resv_huge_pages += delta;
Adam Litkee4e574b2007-10-16 01:26:19 -0700910 ret = 0;
911free:
Adam Litke19fc3f02008-04-28 02:12:20 -0700912 /* Free the needed pages to the hugetlb pool */
Adam Litkee4e574b2007-10-16 01:26:19 -0700913 list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
Adam Litke19fc3f02008-04-28 02:12:20 -0700914 if ((--needed) < 0)
915 break;
Adam Litkee4e574b2007-10-16 01:26:19 -0700916 list_del(&page->lru);
Andi Kleena5516432008-07-23 21:27:41 -0700917 enqueue_huge_page(h, page);
Adam Litke19fc3f02008-04-28 02:12:20 -0700918 }
919
920 /* Free unnecessary surplus pages to the buddy allocator */
921 if (!list_empty(&surplus_list)) {
922 spin_unlock(&hugetlb_lock);
923 list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
924 list_del(&page->lru);
Adam Litkeaf767cb2007-10-16 01:26:25 -0700925 /*
Adam Litke2668db92008-03-10 11:43:50 -0700926 * The page has a reference count of zero already, so
927 * call free_huge_page directly instead of using
928 * put_page. This must be done with hugetlb_lock
Adam Litkeaf767cb2007-10-16 01:26:25 -0700929 * unlocked which is safe because free_huge_page takes
930 * hugetlb_lock before deciding how to free the page.
931 */
Adam Litke2668db92008-03-10 11:43:50 -0700932 free_huge_page(page);
Adam Litkeaf767cb2007-10-16 01:26:25 -0700933 }
Adam Litke19fc3f02008-04-28 02:12:20 -0700934 spin_lock(&hugetlb_lock);
Adam Litkee4e574b2007-10-16 01:26:19 -0700935 }
936
937 return ret;
938}
939
940/*
941 * When releasing a hugetlb pool reservation, any surplus pages that were
942 * allocated to satisfy the reservation must be explicitly freed if they were
943 * never used.
Lee Schermerhorn685f3452009-09-21 17:01:23 -0700944 * Called with hugetlb_lock held.
Adam Litkee4e574b2007-10-16 01:26:19 -0700945 */
Andi Kleena5516432008-07-23 21:27:41 -0700946static void return_unused_surplus_pages(struct hstate *h,
947 unsigned long unused_resv_pages)
Adam Litkee4e574b2007-10-16 01:26:19 -0700948{
Adam Litkee4e574b2007-10-16 01:26:19 -0700949 unsigned long nr_pages;
950
Adam Litkeac09b3a2008-03-04 14:29:38 -0800951 /* Uncommit the reservation */
Andi Kleena5516432008-07-23 21:27:41 -0700952 h->resv_huge_pages -= unused_resv_pages;
Adam Litkeac09b3a2008-03-04 14:29:38 -0800953
Andi Kleenaa888a72008-07-23 21:27:47 -0700954 /* Cannot return gigantic pages currently */
955 if (h->order >= MAX_ORDER)
956 return;
957
Andi Kleena5516432008-07-23 21:27:41 -0700958 nr_pages = min(unused_resv_pages, h->surplus_huge_pages);
Adam Litkee4e574b2007-10-16 01:26:19 -0700959
Lee Schermerhorn685f3452009-09-21 17:01:23 -0700960 /*
961 * We want to release as many surplus pages as possible, spread
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -0800962 * evenly across all nodes with memory. Iterate across these nodes
963 * until we can no longer free unreserved surplus pages. This occurs
964 * when the nodes with surplus pages have no free pages.
965 * free_pool_huge_page() will balance the the freed pages across the
966 * on-line nodes with memory and will handle the hstate accounting.
Lee Schermerhorn685f3452009-09-21 17:01:23 -0700967 */
968 while (nr_pages--) {
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -0800969 if (!free_pool_huge_page(h, &node_states[N_HIGH_MEMORY], 1))
Lee Schermerhorn685f3452009-09-21 17:01:23 -0700970 break;
Adam Litkee4e574b2007-10-16 01:26:19 -0700971 }
972}
973
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700974/*
975 * Determine if the huge page at addr within the vma has an associated
976 * reservation. Where it does not we will need to logically increase
977 * reservation and actually increase quota before an allocation can occur.
978 * Where any new reservation would be required the reservation change is
979 * prepared, but not committed. Once the page has been quota'd allocated
980 * an instantiated the change should be committed via vma_commit_reservation.
981 * No action is required on failure.
982 */
Roel Kluine2f17d92009-03-31 15:23:15 -0700983static long vma_needs_reservation(struct hstate *h,
Andi Kleena5516432008-07-23 21:27:41 -0700984 struct vm_area_struct *vma, unsigned long addr)
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700985{
986 struct address_space *mapping = vma->vm_file->f_mapping;
987 struct inode *inode = mapping->host;
988
Mel Gormanf83a2752009-05-28 14:34:40 -0700989 if (vma->vm_flags & VM_MAYSHARE) {
Andi Kleena5516432008-07-23 21:27:41 -0700990 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700991 return region_chg(&inode->i_mapping->private_list,
992 idx, idx + 1);
993
Andy Whitcroft84afd992008-07-23 21:27:32 -0700994 } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
995 return 1;
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -0700996
Andy Whitcroft84afd992008-07-23 21:27:32 -0700997 } else {
Roel Kluine2f17d92009-03-31 15:23:15 -0700998 long err;
Andi Kleena5516432008-07-23 21:27:41 -0700999 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
Andy Whitcroft84afd992008-07-23 21:27:32 -07001000 struct resv_map *reservations = vma_resv_map(vma);
1001
1002 err = region_chg(&reservations->regions, idx, idx + 1);
1003 if (err < 0)
1004 return err;
1005 return 0;
1006 }
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -07001007}
Andi Kleena5516432008-07-23 21:27:41 -07001008static void vma_commit_reservation(struct hstate *h,
1009 struct vm_area_struct *vma, unsigned long addr)
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -07001010{
1011 struct address_space *mapping = vma->vm_file->f_mapping;
1012 struct inode *inode = mapping->host;
1013
Mel Gormanf83a2752009-05-28 14:34:40 -07001014 if (vma->vm_flags & VM_MAYSHARE) {
Andi Kleena5516432008-07-23 21:27:41 -07001015 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -07001016 region_add(&inode->i_mapping->private_list, idx, idx + 1);
Andy Whitcroft84afd992008-07-23 21:27:32 -07001017
1018 } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
Andi Kleena5516432008-07-23 21:27:41 -07001019 pgoff_t idx = vma_hugecache_offset(h, vma, addr);
Andy Whitcroft84afd992008-07-23 21:27:32 -07001020 struct resv_map *reservations = vma_resv_map(vma);
1021
1022 /* Mark this page used in the map. */
1023 region_add(&reservations->regions, idx, idx + 1);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -07001024 }
1025}
1026
David Gibson27a85ef2006-03-22 00:08:56 -08001027static struct page *alloc_huge_page(struct vm_area_struct *vma,
Mel Gorman04f2cbe2008-07-23 21:27:25 -07001028 unsigned long addr, int avoid_reserve)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001029{
Andi Kleena5516432008-07-23 21:27:41 -07001030 struct hstate *h = hstate_vma(vma);
Adam Litke348ea202007-11-14 16:59:37 -08001031 struct page *page;
Adam Litke2fc39ce2007-11-14 16:59:39 -08001032 struct address_space *mapping = vma->vm_file->f_mapping;
Mel Gormana1e78772008-07-23 21:27:23 -07001033 struct inode *inode = mapping->host;
Roel Kluine2f17d92009-03-31 15:23:15 -07001034 long chg;
Adam Litke2fc39ce2007-11-14 16:59:39 -08001035
Mel Gormana1e78772008-07-23 21:27:23 -07001036 /*
1037 * Processes that did not create the mapping will have no reserves and
1038 * will not have accounted against quota. Check that the quota can be
1039 * made before satisfying the allocation
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -07001040 * MAP_NORESERVE mappings may also need pages and quota allocated
1041 * if no reserve mapping overlaps.
Mel Gormana1e78772008-07-23 21:27:23 -07001042 */
Andi Kleena5516432008-07-23 21:27:41 -07001043 chg = vma_needs_reservation(h, vma, addr);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -07001044 if (chg < 0)
1045 return ERR_PTR(chg);
1046 if (chg)
Mel Gormana1e78772008-07-23 21:27:23 -07001047 if (hugetlb_get_quota(inode->i_mapping, chg))
1048 return ERR_PTR(-ENOSPC);
Mel Gormana1e78772008-07-23 21:27:23 -07001049
1050 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -07001051 page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve);
Mel Gormana1e78772008-07-23 21:27:23 -07001052 spin_unlock(&hugetlb_lock);
1053
1054 if (!page) {
Andi Kleena5516432008-07-23 21:27:41 -07001055 page = alloc_buddy_huge_page(h, vma, addr);
Mel Gormana1e78772008-07-23 21:27:23 -07001056 if (!page) {
1057 hugetlb_put_quota(inode->i_mapping, chg);
Mel Gorman4a6018f2010-05-11 14:06:53 -07001058 return ERR_PTR(-VM_FAULT_SIGBUS);
Mel Gormana1e78772008-07-23 21:27:23 -07001059 }
1060 }
1061
1062 set_page_refcounted(page);
1063 set_page_private(page, (unsigned long) mapping);
1064
Andi Kleena5516432008-07-23 21:27:41 -07001065 vma_commit_reservation(h, vma, addr);
Andy Whitcroftc37f9fb2008-07-23 21:27:30 -07001066
Adam Litke90d8b7e2007-11-14 16:59:42 -08001067 return page;
David Gibsonb45b5bd2006-03-22 00:08:55 -08001068}
1069
Cyrill Gorcunov91f47662009-01-06 14:40:33 -08001070int __weak alloc_bootmem_huge_page(struct hstate *h)
Andi Kleenaa888a72008-07-23 21:27:47 -07001071{
1072 struct huge_bootmem_page *m;
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -08001073 int nr_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
Andi Kleenaa888a72008-07-23 21:27:47 -07001074
1075 while (nr_nodes) {
1076 void *addr;
1077
1078 addr = __alloc_bootmem_node_nopanic(
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001079 NODE_DATA(hstate_next_node_to_alloc(h,
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -08001080 &node_states[N_HIGH_MEMORY])),
Andi Kleenaa888a72008-07-23 21:27:47 -07001081 huge_page_size(h), huge_page_size(h), 0);
1082
1083 if (addr) {
1084 /*
1085 * Use the beginning of the huge page to store the
1086 * huge_bootmem_page struct (until gather_bootmem
1087 * puts them into the mem_map).
1088 */
1089 m = addr;
Cyrill Gorcunov91f47662009-01-06 14:40:33 -08001090 goto found;
Andi Kleenaa888a72008-07-23 21:27:47 -07001091 }
Andi Kleenaa888a72008-07-23 21:27:47 -07001092 nr_nodes--;
1093 }
1094 return 0;
1095
1096found:
1097 BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1));
1098 /* Put them into a private list first because mem_map is not up yet */
1099 list_add(&m->list, &huge_boot_pages);
1100 m->hstate = h;
1101 return 1;
1102}
1103
Andy Whitcroft18229df2008-11-06 12:53:27 -08001104static void prep_compound_huge_page(struct page *page, int order)
1105{
1106 if (unlikely(order > (MAX_ORDER - 1)))
1107 prep_compound_gigantic_page(page, order);
1108 else
1109 prep_compound_page(page, order);
1110}
1111
Andi Kleenaa888a72008-07-23 21:27:47 -07001112/* Put bootmem huge pages into the standard lists after mem_map is up */
1113static void __init gather_bootmem_prealloc(void)
1114{
1115 struct huge_bootmem_page *m;
1116
1117 list_for_each_entry(m, &huge_boot_pages, list) {
1118 struct page *page = virt_to_page(m);
1119 struct hstate *h = m->hstate;
1120 __ClearPageReserved(page);
1121 WARN_ON(page_count(page) != 1);
Andy Whitcroft18229df2008-11-06 12:53:27 -08001122 prep_compound_huge_page(page, h->order);
Andi Kleenaa888a72008-07-23 21:27:47 -07001123 prep_new_huge_page(h, page, page_to_nid(page));
1124 }
1125}
1126
Andi Kleen8faa8b02008-07-23 21:27:48 -07001127static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128{
1129 unsigned long i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001130
Andi Kleene5ff2152008-07-23 21:27:42 -07001131 for (i = 0; i < h->max_huge_pages; ++i) {
Andi Kleenaa888a72008-07-23 21:27:47 -07001132 if (h->order >= MAX_ORDER) {
1133 if (!alloc_bootmem_huge_page(h))
1134 break;
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -08001135 } else if (!alloc_fresh_huge_page(h,
1136 &node_states[N_HIGH_MEMORY]))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138 }
Andi Kleen8faa8b02008-07-23 21:27:48 -07001139 h->max_huge_pages = i;
Andi Kleene5ff2152008-07-23 21:27:42 -07001140}
1141
1142static void __init hugetlb_init_hstates(void)
1143{
1144 struct hstate *h;
1145
1146 for_each_hstate(h) {
Andi Kleen8faa8b02008-07-23 21:27:48 -07001147 /* oversize hugepages were init'ed in early boot */
1148 if (h->order < MAX_ORDER)
1149 hugetlb_hstate_alloc_pages(h);
Andi Kleene5ff2152008-07-23 21:27:42 -07001150 }
1151}
1152
Andi Kleen4abd32d2008-07-23 21:27:49 -07001153static char * __init memfmt(char *buf, unsigned long n)
1154{
1155 if (n >= (1UL << 30))
1156 sprintf(buf, "%lu GB", n >> 30);
1157 else if (n >= (1UL << 20))
1158 sprintf(buf, "%lu MB", n >> 20);
1159 else
1160 sprintf(buf, "%lu KB", n >> 10);
1161 return buf;
1162}
1163
Andi Kleene5ff2152008-07-23 21:27:42 -07001164static void __init report_hugepages(void)
1165{
1166 struct hstate *h;
1167
1168 for_each_hstate(h) {
Andi Kleen4abd32d2008-07-23 21:27:49 -07001169 char buf[32];
1170 printk(KERN_INFO "HugeTLB registered %s page size, "
1171 "pre-allocated %ld pages\n",
1172 memfmt(buf, huge_page_size(h)),
1173 h->free_huge_pages);
Andi Kleene5ff2152008-07-23 21:27:42 -07001174 }
1175}
1176
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177#ifdef CONFIG_HIGHMEM
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001178static void try_to_free_low(struct hstate *h, unsigned long count,
1179 nodemask_t *nodes_allowed)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001180{
Christoph Lameter4415cc82006-09-25 23:31:55 -07001181 int i;
1182
Andi Kleenaa888a72008-07-23 21:27:47 -07001183 if (h->order >= MAX_ORDER)
1184 return;
1185
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001186 for_each_node_mask(i, *nodes_allowed) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187 struct page *page, *next;
Andi Kleena5516432008-07-23 21:27:41 -07001188 struct list_head *freel = &h->hugepage_freelists[i];
1189 list_for_each_entry_safe(page, next, freel, lru) {
1190 if (count >= h->nr_huge_pages)
Adam Litke6b0c8802007-10-16 01:26:23 -07001191 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192 if (PageHighMem(page))
1193 continue;
1194 list_del(&page->lru);
Andi Kleene5ff2152008-07-23 21:27:42 -07001195 update_and_free_page(h, page);
Andi Kleena5516432008-07-23 21:27:41 -07001196 h->free_huge_pages--;
1197 h->free_huge_pages_node[page_to_nid(page)]--;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198 }
1199 }
1200}
1201#else
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001202static inline void try_to_free_low(struct hstate *h, unsigned long count,
1203 nodemask_t *nodes_allowed)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001204{
1205}
1206#endif
1207
Wu Fengguang20a03072009-06-16 15:32:22 -07001208/*
1209 * Increment or decrement surplus_huge_pages. Keep node-specific counters
1210 * balanced by operating on them in a round-robin fashion.
1211 * Returns 1 if an adjustment was made.
1212 */
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001213static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed,
1214 int delta)
Wu Fengguang20a03072009-06-16 15:32:22 -07001215{
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001216 int start_nid, next_nid;
Wu Fengguang20a03072009-06-16 15:32:22 -07001217 int ret = 0;
1218
1219 VM_BUG_ON(delta != -1 && delta != 1);
Wu Fengguang20a03072009-06-16 15:32:22 -07001220
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001221 if (delta < 0)
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001222 start_nid = hstate_next_node_to_alloc(h, nodes_allowed);
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001223 else
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001224 start_nid = hstate_next_node_to_free(h, nodes_allowed);
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001225 next_nid = start_nid;
1226
1227 do {
1228 int nid = next_nid;
1229 if (delta < 0) {
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001230 /*
1231 * To shrink on this node, there must be a surplus page
1232 */
Lee Schermerhorn9a76db02009-12-14 17:58:15 -08001233 if (!h->surplus_huge_pages_node[nid]) {
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001234 next_nid = hstate_next_node_to_alloc(h,
1235 nodes_allowed);
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001236 continue;
Lee Schermerhorn9a76db02009-12-14 17:58:15 -08001237 }
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001238 }
1239 if (delta > 0) {
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001240 /*
1241 * Surplus cannot exceed the total number of pages
1242 */
1243 if (h->surplus_huge_pages_node[nid] >=
Lee Schermerhorn9a76db02009-12-14 17:58:15 -08001244 h->nr_huge_pages_node[nid]) {
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001245 next_nid = hstate_next_node_to_free(h,
1246 nodes_allowed);
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001247 continue;
Lee Schermerhorn9a76db02009-12-14 17:58:15 -08001248 }
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001249 }
Wu Fengguang20a03072009-06-16 15:32:22 -07001250
1251 h->surplus_huge_pages += delta;
1252 h->surplus_huge_pages_node[nid] += delta;
1253 ret = 1;
1254 break;
Lee Schermerhorne8c5c822009-09-21 17:01:22 -07001255 } while (next_nid != start_nid);
Wu Fengguang20a03072009-06-16 15:32:22 -07001256
Wu Fengguang20a03072009-06-16 15:32:22 -07001257 return ret;
1258}
1259
Andi Kleena5516432008-07-23 21:27:41 -07001260#define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001261static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count,
1262 nodemask_t *nodes_allowed)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263{
Adam Litke7893d1d2007-10-16 01:26:18 -07001264 unsigned long min_count, ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001265
Andi Kleenaa888a72008-07-23 21:27:47 -07001266 if (h->order >= MAX_ORDER)
1267 return h->max_huge_pages;
1268
Adam Litke7893d1d2007-10-16 01:26:18 -07001269 /*
1270 * Increase the pool size
1271 * First take pages out of surplus state. Then make up the
1272 * remaining difference by allocating fresh huge pages.
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -08001273 *
1274 * We might race with alloc_buddy_huge_page() here and be unable
1275 * to convert a surplus huge page to a normal huge page. That is
1276 * not critical, though, it just means the overall size of the
1277 * pool might be one hugepage larger than it needs to be, but
1278 * within all the constraints specified by the sysctls.
Adam Litke7893d1d2007-10-16 01:26:18 -07001279 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001280 spin_lock(&hugetlb_lock);
Andi Kleena5516432008-07-23 21:27:41 -07001281 while (h->surplus_huge_pages && count > persistent_huge_pages(h)) {
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001282 if (!adjust_pool_surplus(h, nodes_allowed, -1))
Adam Litke7893d1d2007-10-16 01:26:18 -07001283 break;
1284 }
1285
Andi Kleena5516432008-07-23 21:27:41 -07001286 while (count > persistent_huge_pages(h)) {
Adam Litke7893d1d2007-10-16 01:26:18 -07001287 /*
1288 * If this allocation races such that we no longer need the
1289 * page, free_huge_page will handle it by freeing the page
1290 * and reducing the surplus.
1291 */
1292 spin_unlock(&hugetlb_lock);
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001293 ret = alloc_fresh_huge_page(h, nodes_allowed);
Adam Litke7893d1d2007-10-16 01:26:18 -07001294 spin_lock(&hugetlb_lock);
1295 if (!ret)
1296 goto out;
1297
Mel Gorman536240f2009-12-14 17:59:56 -08001298 /* Bail for signals. Probably ctrl-c from user */
1299 if (signal_pending(current))
1300 goto out;
Adam Litke7893d1d2007-10-16 01:26:18 -07001301 }
Adam Litke7893d1d2007-10-16 01:26:18 -07001302
1303 /*
1304 * Decrease the pool size
1305 * First return free pages to the buddy allocator (being careful
1306 * to keep enough around to satisfy reservations). Then place
1307 * pages into surplus state as needed so the pool will shrink
1308 * to the desired size as pages become free.
Nishanth Aravamudand1c3fb12007-12-17 16:20:12 -08001309 *
1310 * By placing pages into the surplus state independent of the
1311 * overcommit value, we are allowing the surplus pool size to
1312 * exceed overcommit. There are few sane options here. Since
1313 * alloc_buddy_huge_page() is checking the global counter,
1314 * though, we'll note that we're not allowed to exceed surplus
1315 * and won't grow the pool anywhere else. Not until one of the
1316 * sysctls are changed, or the surplus pages go out of use.
Adam Litke7893d1d2007-10-16 01:26:18 -07001317 */
Andi Kleena5516432008-07-23 21:27:41 -07001318 min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages;
Adam Litke6b0c8802007-10-16 01:26:23 -07001319 min_count = max(count, min_count);
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001320 try_to_free_low(h, min_count, nodes_allowed);
Andi Kleena5516432008-07-23 21:27:41 -07001321 while (min_count < persistent_huge_pages(h)) {
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001322 if (!free_pool_huge_page(h, nodes_allowed, 0))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001323 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001324 }
Andi Kleena5516432008-07-23 21:27:41 -07001325 while (count < persistent_huge_pages(h)) {
Lee Schermerhorn6ae11b22009-12-14 17:58:16 -08001326 if (!adjust_pool_surplus(h, nodes_allowed, 1))
Adam Litke7893d1d2007-10-16 01:26:18 -07001327 break;
1328 }
1329out:
Andi Kleena5516432008-07-23 21:27:41 -07001330 ret = persistent_huge_pages(h);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331 spin_unlock(&hugetlb_lock);
Adam Litke7893d1d2007-10-16 01:26:18 -07001332 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001333}
1334
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001335#define HSTATE_ATTR_RO(_name) \
1336 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
1337
1338#define HSTATE_ATTR(_name) \
1339 static struct kobj_attribute _name##_attr = \
1340 __ATTR(_name, 0644, _name##_show, _name##_store)
1341
1342static struct kobject *hugepages_kobj;
1343static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];
1344
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001345static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp);
1346
1347static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp)
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001348{
1349 int i;
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001350
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001351 for (i = 0; i < HUGE_MAX_HSTATE; i++)
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001352 if (hstate_kobjs[i] == kobj) {
1353 if (nidp)
1354 *nidp = NUMA_NO_NODE;
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001355 return &hstates[i];
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001356 }
1357
1358 return kobj_to_node_hstate(kobj, nidp);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001359}
1360
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001361static ssize_t nr_hugepages_show_common(struct kobject *kobj,
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001362 struct kobj_attribute *attr, char *buf)
1363{
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001364 struct hstate *h;
1365 unsigned long nr_huge_pages;
1366 int nid;
1367
1368 h = kobj_to_hstate(kobj, &nid);
1369 if (nid == NUMA_NO_NODE)
1370 nr_huge_pages = h->nr_huge_pages;
1371 else
1372 nr_huge_pages = h->nr_huge_pages_node[nid];
1373
1374 return sprintf(buf, "%lu\n", nr_huge_pages);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001375}
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001376static ssize_t nr_hugepages_store_common(bool obey_mempolicy,
1377 struct kobject *kobj, struct kobj_attribute *attr,
1378 const char *buf, size_t len)
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001379{
1380 int err;
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001381 int nid;
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001382 unsigned long count;
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001383 struct hstate *h;
David Rientjesbad44b52009-12-14 17:58:38 -08001384 NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001385
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001386 err = strict_strtoul(buf, 10, &count);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001387 if (err)
1388 return 0;
1389
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001390 h = kobj_to_hstate(kobj, &nid);
1391 if (nid == NUMA_NO_NODE) {
1392 /*
1393 * global hstate attribute
1394 */
1395 if (!(obey_mempolicy &&
1396 init_nodemask_of_mempolicy(nodes_allowed))) {
1397 NODEMASK_FREE(nodes_allowed);
1398 nodes_allowed = &node_states[N_HIGH_MEMORY];
1399 }
1400 } else if (nodes_allowed) {
1401 /*
1402 * per node hstate attribute: adjust count to global,
1403 * but restrict alloc/free to the specified node.
1404 */
1405 count += h->nr_huge_pages - h->nr_huge_pages_node[nid];
1406 init_nodemask_of_node(nodes_allowed, nid);
1407 } else
1408 nodes_allowed = &node_states[N_HIGH_MEMORY];
1409
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001410 h->max_huge_pages = set_max_huge_pages(h, count, nodes_allowed);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001411
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -08001412 if (nodes_allowed != &node_states[N_HIGH_MEMORY])
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001413 NODEMASK_FREE(nodes_allowed);
1414
1415 return len;
1416}
1417
1418static ssize_t nr_hugepages_show(struct kobject *kobj,
1419 struct kobj_attribute *attr, char *buf)
1420{
1421 return nr_hugepages_show_common(kobj, attr, buf);
1422}
1423
1424static ssize_t nr_hugepages_store(struct kobject *kobj,
1425 struct kobj_attribute *attr, const char *buf, size_t len)
1426{
1427 return nr_hugepages_store_common(false, kobj, attr, buf, len);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001428}
1429HSTATE_ATTR(nr_hugepages);
1430
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001431#ifdef CONFIG_NUMA
1432
1433/*
1434 * hstate attribute for optionally mempolicy-based constraint on persistent
1435 * huge page alloc/free.
1436 */
1437static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj,
1438 struct kobj_attribute *attr, char *buf)
1439{
1440 return nr_hugepages_show_common(kobj, attr, buf);
1441}
1442
1443static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj,
1444 struct kobj_attribute *attr, const char *buf, size_t len)
1445{
1446 return nr_hugepages_store_common(true, kobj, attr, buf, len);
1447}
1448HSTATE_ATTR(nr_hugepages_mempolicy);
1449#endif
1450
1451
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001452static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj,
1453 struct kobj_attribute *attr, char *buf)
1454{
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001455 struct hstate *h = kobj_to_hstate(kobj, NULL);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001456 return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages);
1457}
1458static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj,
1459 struct kobj_attribute *attr, const char *buf, size_t count)
1460{
1461 int err;
1462 unsigned long input;
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001463 struct hstate *h = kobj_to_hstate(kobj, NULL);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001464
1465 err = strict_strtoul(buf, 10, &input);
1466 if (err)
1467 return 0;
1468
1469 spin_lock(&hugetlb_lock);
1470 h->nr_overcommit_huge_pages = input;
1471 spin_unlock(&hugetlb_lock);
1472
1473 return count;
1474}
1475HSTATE_ATTR(nr_overcommit_hugepages);
1476
1477static ssize_t free_hugepages_show(struct kobject *kobj,
1478 struct kobj_attribute *attr, char *buf)
1479{
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001480 struct hstate *h;
1481 unsigned long free_huge_pages;
1482 int nid;
1483
1484 h = kobj_to_hstate(kobj, &nid);
1485 if (nid == NUMA_NO_NODE)
1486 free_huge_pages = h->free_huge_pages;
1487 else
1488 free_huge_pages = h->free_huge_pages_node[nid];
1489
1490 return sprintf(buf, "%lu\n", free_huge_pages);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001491}
1492HSTATE_ATTR_RO(free_hugepages);
1493
1494static ssize_t resv_hugepages_show(struct kobject *kobj,
1495 struct kobj_attribute *attr, char *buf)
1496{
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001497 struct hstate *h = kobj_to_hstate(kobj, NULL);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001498 return sprintf(buf, "%lu\n", h->resv_huge_pages);
1499}
1500HSTATE_ATTR_RO(resv_hugepages);
1501
1502static ssize_t surplus_hugepages_show(struct kobject *kobj,
1503 struct kobj_attribute *attr, char *buf)
1504{
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001505 struct hstate *h;
1506 unsigned long surplus_huge_pages;
1507 int nid;
1508
1509 h = kobj_to_hstate(kobj, &nid);
1510 if (nid == NUMA_NO_NODE)
1511 surplus_huge_pages = h->surplus_huge_pages;
1512 else
1513 surplus_huge_pages = h->surplus_huge_pages_node[nid];
1514
1515 return sprintf(buf, "%lu\n", surplus_huge_pages);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001516}
1517HSTATE_ATTR_RO(surplus_hugepages);
1518
1519static struct attribute *hstate_attrs[] = {
1520 &nr_hugepages_attr.attr,
1521 &nr_overcommit_hugepages_attr.attr,
1522 &free_hugepages_attr.attr,
1523 &resv_hugepages_attr.attr,
1524 &surplus_hugepages_attr.attr,
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001525#ifdef CONFIG_NUMA
1526 &nr_hugepages_mempolicy_attr.attr,
1527#endif
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001528 NULL,
1529};
1530
1531static struct attribute_group hstate_attr_group = {
1532 .attrs = hstate_attrs,
1533};
1534
Jeff Mahoney094e9532010-02-02 13:44:14 -08001535static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent,
1536 struct kobject **hstate_kobjs,
1537 struct attribute_group *hstate_attr_group)
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001538{
1539 int retval;
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001540 int hi = h - hstates;
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001541
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001542 hstate_kobjs[hi] = kobject_create_and_add(h->name, parent);
1543 if (!hstate_kobjs[hi])
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001544 return -ENOMEM;
1545
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001546 retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001547 if (retval)
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001548 kobject_put(hstate_kobjs[hi]);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001549
1550 return retval;
1551}
1552
1553static void __init hugetlb_sysfs_init(void)
1554{
1555 struct hstate *h;
1556 int err;
1557
1558 hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj);
1559 if (!hugepages_kobj)
1560 return;
1561
1562 for_each_hstate(h) {
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001563 err = hugetlb_sysfs_add_hstate(h, hugepages_kobj,
1564 hstate_kobjs, &hstate_attr_group);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001565 if (err)
1566 printk(KERN_ERR "Hugetlb: Unable to add hstate %s",
1567 h->name);
1568 }
1569}
1570
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001571#ifdef CONFIG_NUMA
1572
1573/*
1574 * node_hstate/s - associate per node hstate attributes, via their kobjects,
1575 * with node sysdevs in node_devices[] using a parallel array. The array
1576 * index of a node sysdev or _hstate == node id.
1577 * This is here to avoid any static dependency of the node sysdev driver, in
1578 * the base kernel, on the hugetlb module.
1579 */
1580struct node_hstate {
1581 struct kobject *hugepages_kobj;
1582 struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];
1583};
1584struct node_hstate node_hstates[MAX_NUMNODES];
1585
1586/*
1587 * A subset of global hstate attributes for node sysdevs
1588 */
1589static struct attribute *per_node_hstate_attrs[] = {
1590 &nr_hugepages_attr.attr,
1591 &free_hugepages_attr.attr,
1592 &surplus_hugepages_attr.attr,
1593 NULL,
1594};
1595
1596static struct attribute_group per_node_hstate_attr_group = {
1597 .attrs = per_node_hstate_attrs,
1598};
1599
1600/*
1601 * kobj_to_node_hstate - lookup global hstate for node sysdev hstate attr kobj.
1602 * Returns node id via non-NULL nidp.
1603 */
1604static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp)
1605{
1606 int nid;
1607
1608 for (nid = 0; nid < nr_node_ids; nid++) {
1609 struct node_hstate *nhs = &node_hstates[nid];
1610 int i;
1611 for (i = 0; i < HUGE_MAX_HSTATE; i++)
1612 if (nhs->hstate_kobjs[i] == kobj) {
1613 if (nidp)
1614 *nidp = nid;
1615 return &hstates[i];
1616 }
1617 }
1618
1619 BUG();
1620 return NULL;
1621}
1622
1623/*
1624 * Unregister hstate attributes from a single node sysdev.
1625 * No-op if no hstate attributes attached.
1626 */
1627void hugetlb_unregister_node(struct node *node)
1628{
1629 struct hstate *h;
1630 struct node_hstate *nhs = &node_hstates[node->sysdev.id];
1631
1632 if (!nhs->hugepages_kobj)
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -08001633 return; /* no hstate attributes */
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001634
1635 for_each_hstate(h)
1636 if (nhs->hstate_kobjs[h - hstates]) {
1637 kobject_put(nhs->hstate_kobjs[h - hstates]);
1638 nhs->hstate_kobjs[h - hstates] = NULL;
1639 }
1640
1641 kobject_put(nhs->hugepages_kobj);
1642 nhs->hugepages_kobj = NULL;
1643}
1644
1645/*
1646 * hugetlb module exit: unregister hstate attributes from node sysdevs
1647 * that have them.
1648 */
1649static void hugetlb_unregister_all_nodes(void)
1650{
1651 int nid;
1652
1653 /*
1654 * disable node sysdev registrations.
1655 */
1656 register_hugetlbfs_with_node(NULL, NULL);
1657
1658 /*
1659 * remove hstate attributes from any nodes that have them.
1660 */
1661 for (nid = 0; nid < nr_node_ids; nid++)
1662 hugetlb_unregister_node(&node_devices[nid]);
1663}
1664
1665/*
1666 * Register hstate attributes for a single node sysdev.
1667 * No-op if attributes already registered.
1668 */
1669void hugetlb_register_node(struct node *node)
1670{
1671 struct hstate *h;
1672 struct node_hstate *nhs = &node_hstates[node->sysdev.id];
1673 int err;
1674
1675 if (nhs->hugepages_kobj)
1676 return; /* already allocated */
1677
1678 nhs->hugepages_kobj = kobject_create_and_add("hugepages",
1679 &node->sysdev.kobj);
1680 if (!nhs->hugepages_kobj)
1681 return;
1682
1683 for_each_hstate(h) {
1684 err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj,
1685 nhs->hstate_kobjs,
1686 &per_node_hstate_attr_group);
1687 if (err) {
1688 printk(KERN_ERR "Hugetlb: Unable to add hstate %s"
1689 " for node %d\n",
1690 h->name, node->sysdev.id);
1691 hugetlb_unregister_node(node);
1692 break;
1693 }
1694 }
1695}
1696
1697/*
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -08001698 * hugetlb init time: register hstate attributes for all registered node
1699 * sysdevs of nodes that have memory. All on-line nodes should have
1700 * registered their associated sysdev by this time.
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001701 */
1702static void hugetlb_register_all_nodes(void)
1703{
1704 int nid;
1705
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -08001706 for_each_node_state(nid, N_HIGH_MEMORY) {
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001707 struct node *node = &node_devices[nid];
1708 if (node->sysdev.id == nid)
1709 hugetlb_register_node(node);
1710 }
1711
1712 /*
1713 * Let the node sysdev driver know we're here so it can
1714 * [un]register hstate attributes on node hotplug.
1715 */
1716 register_hugetlbfs_with_node(hugetlb_register_node,
1717 hugetlb_unregister_node);
1718}
1719#else /* !CONFIG_NUMA */
1720
1721static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp)
1722{
1723 BUG();
1724 if (nidp)
1725 *nidp = -1;
1726 return NULL;
1727}
1728
1729static void hugetlb_unregister_all_nodes(void) { }
1730
1731static void hugetlb_register_all_nodes(void) { }
1732
1733#endif
1734
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001735static void __exit hugetlb_exit(void)
1736{
1737 struct hstate *h;
1738
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001739 hugetlb_unregister_all_nodes();
1740
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001741 for_each_hstate(h) {
1742 kobject_put(hstate_kobjs[h - hstates]);
1743 }
1744
1745 kobject_put(hugepages_kobj);
1746}
1747module_exit(hugetlb_exit);
1748
1749static int __init hugetlb_init(void)
1750{
Benjamin Herrenschmidt0ef89d22008-07-31 00:07:30 -07001751 /* Some platform decide whether they support huge pages at boot
1752 * time. On these, such as powerpc, HPAGE_SHIFT is set to 0 when
1753 * there is no such support
1754 */
1755 if (HPAGE_SHIFT == 0)
1756 return 0;
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001757
Nick Piggine11bfbf2008-07-23 21:27:52 -07001758 if (!size_to_hstate(default_hstate_size)) {
1759 default_hstate_size = HPAGE_SIZE;
1760 if (!size_to_hstate(default_hstate_size))
1761 hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001762 }
Nick Piggine11bfbf2008-07-23 21:27:52 -07001763 default_hstate_idx = size_to_hstate(default_hstate_size) - hstates;
1764 if (default_hstate_max_huge_pages)
1765 default_hstate.max_huge_pages = default_hstate_max_huge_pages;
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001766
1767 hugetlb_init_hstates();
1768
Andi Kleenaa888a72008-07-23 21:27:47 -07001769 gather_bootmem_prealloc();
1770
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001771 report_hugepages();
1772
1773 hugetlb_sysfs_init();
1774
Lee Schermerhorn9a305232009-12-14 17:58:25 -08001775 hugetlb_register_all_nodes();
1776
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001777 return 0;
1778}
1779module_init(hugetlb_init);
1780
1781/* Should be called on processing a hugepagesz=... option */
1782void __init hugetlb_add_hstate(unsigned order)
1783{
1784 struct hstate *h;
Andi Kleen8faa8b02008-07-23 21:27:48 -07001785 unsigned long i;
1786
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001787 if (size_to_hstate(PAGE_SIZE << order)) {
1788 printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n");
1789 return;
1790 }
1791 BUG_ON(max_hstate >= HUGE_MAX_HSTATE);
1792 BUG_ON(order == 0);
1793 h = &hstates[max_hstate++];
1794 h->order = order;
1795 h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1);
Andi Kleen8faa8b02008-07-23 21:27:48 -07001796 h->nr_huge_pages = 0;
1797 h->free_huge_pages = 0;
1798 for (i = 0; i < MAX_NUMNODES; ++i)
1799 INIT_LIST_HEAD(&h->hugepage_freelists[i]);
Lee Schermerhorn9b5e5d02009-12-14 17:58:32 -08001800 h->next_nid_to_alloc = first_node(node_states[N_HIGH_MEMORY]);
1801 h->next_nid_to_free = first_node(node_states[N_HIGH_MEMORY]);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001802 snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
1803 huge_page_size(h)/1024);
Andi Kleen8faa8b02008-07-23 21:27:48 -07001804
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001805 parsed_hstate = h;
1806}
1807
Nick Piggine11bfbf2008-07-23 21:27:52 -07001808static int __init hugetlb_nrpages_setup(char *s)
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001809{
1810 unsigned long *mhp;
Andi Kleen8faa8b02008-07-23 21:27:48 -07001811 static unsigned long *last_mhp;
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001812
1813 /*
1814 * !max_hstate means we haven't parsed a hugepagesz= parameter yet,
1815 * so this hugepages= parameter goes to the "default hstate".
1816 */
1817 if (!max_hstate)
1818 mhp = &default_hstate_max_huge_pages;
1819 else
1820 mhp = &parsed_hstate->max_huge_pages;
1821
Andi Kleen8faa8b02008-07-23 21:27:48 -07001822 if (mhp == last_mhp) {
1823 printk(KERN_WARNING "hugepages= specified twice without "
1824 "interleaving hugepagesz=, ignoring\n");
1825 return 1;
1826 }
1827
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001828 if (sscanf(s, "%lu", mhp) <= 0)
1829 *mhp = 0;
1830
Andi Kleen8faa8b02008-07-23 21:27:48 -07001831 /*
1832 * Global state is always initialized later in hugetlb_init.
1833 * But we need to allocate >= MAX_ORDER hstates here early to still
1834 * use the bootmem allocator.
1835 */
1836 if (max_hstate && parsed_hstate->order >= MAX_ORDER)
1837 hugetlb_hstate_alloc_pages(parsed_hstate);
1838
1839 last_mhp = mhp;
1840
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001841 return 1;
1842}
Nick Piggine11bfbf2008-07-23 21:27:52 -07001843__setup("hugepages=", hugetlb_nrpages_setup);
1844
1845static int __init hugetlb_default_setup(char *s)
1846{
1847 default_hstate_size = memparse(s, &s);
1848 return 1;
1849}
1850__setup("default_hugepagesz=", hugetlb_default_setup);
Nishanth Aravamudana3437872008-07-23 21:27:44 -07001851
Nishanth Aravamudan8a213462008-07-25 19:44:37 -07001852static unsigned int cpuset_mems_nr(unsigned int *array)
1853{
1854 int node;
1855 unsigned int nr = 0;
1856
1857 for_each_node_mask(node, cpuset_current_mems_allowed)
1858 nr += array[node];
1859
1860 return nr;
1861}
1862
1863#ifdef CONFIG_SYSCTL
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001864static int hugetlb_sysctl_handler_common(bool obey_mempolicy,
1865 struct ctl_table *table, int write,
1866 void __user *buffer, size_t *length, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001867{
Andi Kleene5ff2152008-07-23 21:27:42 -07001868 struct hstate *h = &default_hstate;
1869 unsigned long tmp;
1870
1871 if (!write)
1872 tmp = h->max_huge_pages;
1873
1874 table->data = &tmp;
1875 table->maxlen = sizeof(unsigned long);
Alexey Dobriyan8d65af72009-09-23 15:57:19 -07001876 proc_doulongvec_minmax(table, write, buffer, length, ppos);
Andi Kleene5ff2152008-07-23 21:27:42 -07001877
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001878 if (write) {
David Rientjesbad44b52009-12-14 17:58:38 -08001879 NODEMASK_ALLOC(nodemask_t, nodes_allowed,
1880 GFP_KERNEL | __GFP_NORETRY);
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001881 if (!(obey_mempolicy &&
1882 init_nodemask_of_mempolicy(nodes_allowed))) {
1883 NODEMASK_FREE(nodes_allowed);
1884 nodes_allowed = &node_states[N_HIGH_MEMORY];
1885 }
1886 h->max_huge_pages = set_max_huge_pages(h, tmp, nodes_allowed);
1887
1888 if (nodes_allowed != &node_states[N_HIGH_MEMORY])
1889 NODEMASK_FREE(nodes_allowed);
1890 }
Andi Kleene5ff2152008-07-23 21:27:42 -07001891
Linus Torvalds1da177e2005-04-16 15:20:36 -07001892 return 0;
1893}
Mel Gorman396faf02007-07-17 04:03:13 -07001894
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001895int hugetlb_sysctl_handler(struct ctl_table *table, int write,
1896 void __user *buffer, size_t *length, loff_t *ppos)
1897{
1898
1899 return hugetlb_sysctl_handler_common(false, table, write,
1900 buffer, length, ppos);
1901}
1902
1903#ifdef CONFIG_NUMA
1904int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write,
1905 void __user *buffer, size_t *length, loff_t *ppos)
1906{
1907 return hugetlb_sysctl_handler_common(true, table, write,
1908 buffer, length, ppos);
1909}
1910#endif /* CONFIG_NUMA */
1911
Mel Gorman396faf02007-07-17 04:03:13 -07001912int hugetlb_treat_movable_handler(struct ctl_table *table, int write,
Alexey Dobriyan8d65af72009-09-23 15:57:19 -07001913 void __user *buffer,
Mel Gorman396faf02007-07-17 04:03:13 -07001914 size_t *length, loff_t *ppos)
1915{
Alexey Dobriyan8d65af72009-09-23 15:57:19 -07001916 proc_dointvec(table, write, buffer, length, ppos);
Mel Gorman396faf02007-07-17 04:03:13 -07001917 if (hugepages_treat_as_movable)
1918 htlb_alloc_mask = GFP_HIGHUSER_MOVABLE;
1919 else
1920 htlb_alloc_mask = GFP_HIGHUSER;
1921 return 0;
1922}
1923
Nishanth Aravamudana3d0c6a2008-02-08 04:18:18 -08001924int hugetlb_overcommit_handler(struct ctl_table *table, int write,
Alexey Dobriyan8d65af72009-09-23 15:57:19 -07001925 void __user *buffer,
Nishanth Aravamudana3d0c6a2008-02-08 04:18:18 -08001926 size_t *length, loff_t *ppos)
1927{
Andi Kleena5516432008-07-23 21:27:41 -07001928 struct hstate *h = &default_hstate;
Andi Kleene5ff2152008-07-23 21:27:42 -07001929 unsigned long tmp;
1930
1931 if (!write)
1932 tmp = h->nr_overcommit_huge_pages;
1933
1934 table->data = &tmp;
1935 table->maxlen = sizeof(unsigned long);
Alexey Dobriyan8d65af72009-09-23 15:57:19 -07001936 proc_doulongvec_minmax(table, write, buffer, length, ppos);
Andi Kleene5ff2152008-07-23 21:27:42 -07001937
1938 if (write) {
1939 spin_lock(&hugetlb_lock);
1940 h->nr_overcommit_huge_pages = tmp;
1941 spin_unlock(&hugetlb_lock);
1942 }
1943
Nishanth Aravamudana3d0c6a2008-02-08 04:18:18 -08001944 return 0;
1945}
1946
Linus Torvalds1da177e2005-04-16 15:20:36 -07001947#endif /* CONFIG_SYSCTL */
1948
Alexey Dobriyane1759c22008-10-15 23:50:22 +04001949void hugetlb_report_meminfo(struct seq_file *m)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001950{
Andi Kleena5516432008-07-23 21:27:41 -07001951 struct hstate *h = &default_hstate;
Alexey Dobriyane1759c22008-10-15 23:50:22 +04001952 seq_printf(m,
Rik van Riel4f98a2f2008-10-18 20:26:32 -07001953 "HugePages_Total: %5lu\n"
1954 "HugePages_Free: %5lu\n"
1955 "HugePages_Rsvd: %5lu\n"
1956 "HugePages_Surp: %5lu\n"
1957 "Hugepagesize: %8lu kB\n",
Andi Kleena5516432008-07-23 21:27:41 -07001958 h->nr_huge_pages,
1959 h->free_huge_pages,
1960 h->resv_huge_pages,
1961 h->surplus_huge_pages,
1962 1UL << (huge_page_order(h) + PAGE_SHIFT - 10));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001963}
1964
1965int hugetlb_report_node_meminfo(int nid, char *buf)
1966{
Andi Kleena5516432008-07-23 21:27:41 -07001967 struct hstate *h = &default_hstate;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001968 return sprintf(buf,
1969 "Node %d HugePages_Total: %5u\n"
Nishanth Aravamudana1de0912008-03-26 14:37:53 -07001970 "Node %d HugePages_Free: %5u\n"
1971 "Node %d HugePages_Surp: %5u\n",
Andi Kleena5516432008-07-23 21:27:41 -07001972 nid, h->nr_huge_pages_node[nid],
1973 nid, h->free_huge_pages_node[nid],
1974 nid, h->surplus_huge_pages_node[nid]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001975}
1976
Linus Torvalds1da177e2005-04-16 15:20:36 -07001977/* Return the number pages of memory we physically have, in PAGE_SIZE units. */
1978unsigned long hugetlb_total_pages(void)
1979{
Andi Kleena5516432008-07-23 21:27:41 -07001980 struct hstate *h = &default_hstate;
1981 return h->nr_huge_pages * pages_per_huge_page(h);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001982}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001983
Andi Kleena5516432008-07-23 21:27:41 -07001984static int hugetlb_acct_memory(struct hstate *h, long delta)
Mel Gormanfc1b8a72008-07-23 21:27:22 -07001985{
1986 int ret = -ENOMEM;
1987
1988 spin_lock(&hugetlb_lock);
1989 /*
1990 * When cpuset is configured, it breaks the strict hugetlb page
1991 * reservation as the accounting is done on a global variable. Such
1992 * reservation is completely rubbish in the presence of cpuset because
1993 * the reservation is not checked against page availability for the
1994 * current cpuset. Application can still potentially OOM'ed by kernel
1995 * with lack of free htlb page in cpuset that the task is in.
1996 * Attempt to enforce strict accounting with cpuset is almost
1997 * impossible (or too ugly) because cpuset is too fluid that
1998 * task or memory node can be dynamically moved between cpusets.
1999 *
2000 * The change of semantics for shared hugetlb mapping with cpuset is
2001 * undesirable. However, in order to preserve some of the semantics,
2002 * we fall back to check against current free page availability as
2003 * a best attempt and hopefully to minimize the impact of changing
2004 * semantics that cpuset has.
2005 */
2006 if (delta > 0) {
Andi Kleena5516432008-07-23 21:27:41 -07002007 if (gather_surplus_pages(h, delta) < 0)
Mel Gormanfc1b8a72008-07-23 21:27:22 -07002008 goto out;
2009
Andi Kleena5516432008-07-23 21:27:41 -07002010 if (delta > cpuset_mems_nr(h->free_huge_pages_node)) {
2011 return_unused_surplus_pages(h, delta);
Mel Gormanfc1b8a72008-07-23 21:27:22 -07002012 goto out;
2013 }
2014 }
2015
2016 ret = 0;
2017 if (delta < 0)
Andi Kleena5516432008-07-23 21:27:41 -07002018 return_unused_surplus_pages(h, (unsigned long) -delta);
Mel Gormanfc1b8a72008-07-23 21:27:22 -07002019
2020out:
2021 spin_unlock(&hugetlb_lock);
2022 return ret;
2023}
2024
Andy Whitcroft84afd992008-07-23 21:27:32 -07002025static void hugetlb_vm_op_open(struct vm_area_struct *vma)
2026{
2027 struct resv_map *reservations = vma_resv_map(vma);
2028
2029 /*
2030 * This new VMA should share its siblings reservation map if present.
2031 * The VMA will only ever have a valid reservation map pointer where
2032 * it is being copied for another still existing VMA. As that VMA
2033 * has a reference to the reservation map it cannot dissappear until
2034 * after this open call completes. It is therefore safe to take a
2035 * new reference here without additional locking.
2036 */
2037 if (reservations)
2038 kref_get(&reservations->refs);
2039}
2040
Mel Gormana1e78772008-07-23 21:27:23 -07002041static void hugetlb_vm_op_close(struct vm_area_struct *vma)
2042{
Andi Kleena5516432008-07-23 21:27:41 -07002043 struct hstate *h = hstate_vma(vma);
Andy Whitcroft84afd992008-07-23 21:27:32 -07002044 struct resv_map *reservations = vma_resv_map(vma);
2045 unsigned long reserve;
2046 unsigned long start;
2047 unsigned long end;
2048
2049 if (reservations) {
Andi Kleena5516432008-07-23 21:27:41 -07002050 start = vma_hugecache_offset(h, vma, vma->vm_start);
2051 end = vma_hugecache_offset(h, vma, vma->vm_end);
Andy Whitcroft84afd992008-07-23 21:27:32 -07002052
2053 reserve = (end - start) -
2054 region_count(&reservations->regions, start, end);
2055
2056 kref_put(&reservations->refs, resv_map_release);
2057
Adam Litke7251ff782008-07-23 21:27:59 -07002058 if (reserve) {
Andi Kleena5516432008-07-23 21:27:41 -07002059 hugetlb_acct_memory(h, -reserve);
Adam Litke7251ff782008-07-23 21:27:59 -07002060 hugetlb_put_quota(vma->vm_file->f_mapping, reserve);
2061 }
Andy Whitcroft84afd992008-07-23 21:27:32 -07002062 }
Mel Gormana1e78772008-07-23 21:27:23 -07002063}
2064
Linus Torvalds1da177e2005-04-16 15:20:36 -07002065/*
2066 * We cannot handle pagefaults against hugetlb pages at all. They cause
2067 * handle_mm_fault() to try to instantiate regular-sized pages in the
2068 * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get
2069 * this far.
2070 */
Nick Piggind0217ac2007-07-19 01:47:03 -07002071static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002072{
2073 BUG();
Nick Piggind0217ac2007-07-19 01:47:03 -07002074 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002075}
2076
Alexey Dobriyanf0f37e22009-09-27 22:29:37 +04002077const struct vm_operations_struct hugetlb_vm_ops = {
Nick Piggind0217ac2007-07-19 01:47:03 -07002078 .fault = hugetlb_vm_op_fault,
Andy Whitcroft84afd992008-07-23 21:27:32 -07002079 .open = hugetlb_vm_op_open,
Mel Gormana1e78772008-07-23 21:27:23 -07002080 .close = hugetlb_vm_op_close,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002081};
2082
David Gibson1e8f8892006-01-06 00:10:44 -08002083static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page,
2084 int writable)
David Gibson63551ae2005-06-21 17:14:44 -07002085{
2086 pte_t entry;
2087
David Gibson1e8f8892006-01-06 00:10:44 -08002088 if (writable) {
David Gibson63551ae2005-06-21 17:14:44 -07002089 entry =
2090 pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
2091 } else {
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002092 entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot));
David Gibson63551ae2005-06-21 17:14:44 -07002093 }
2094 entry = pte_mkyoung(entry);
2095 entry = pte_mkhuge(entry);
2096
2097 return entry;
2098}
2099
David Gibson1e8f8892006-01-06 00:10:44 -08002100static void set_huge_ptep_writable(struct vm_area_struct *vma,
2101 unsigned long address, pte_t *ptep)
2102{
2103 pte_t entry;
2104
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002105 entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep)));
2106 if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) {
Russell King4b3073e2009-12-18 16:40:18 +00002107 update_mmu_cache(vma, address, ptep);
Benjamin Herrenschmidt8dab5242007-06-16 10:16:12 -07002108 }
David Gibson1e8f8892006-01-06 00:10:44 -08002109}
2110
2111
David Gibson63551ae2005-06-21 17:14:44 -07002112int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
2113 struct vm_area_struct *vma)
2114{
2115 pte_t *src_pte, *dst_pte, entry;
2116 struct page *ptepage;
Hugh Dickins1c598272005-10-19 21:23:43 -07002117 unsigned long addr;
David Gibson1e8f8892006-01-06 00:10:44 -08002118 int cow;
Andi Kleena5516432008-07-23 21:27:41 -07002119 struct hstate *h = hstate_vma(vma);
2120 unsigned long sz = huge_page_size(h);
David Gibson1e8f8892006-01-06 00:10:44 -08002121
2122 cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
David Gibson63551ae2005-06-21 17:14:44 -07002123
Andi Kleena5516432008-07-23 21:27:41 -07002124 for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
Hugh Dickinsc74df322005-10-29 18:16:23 -07002125 src_pte = huge_pte_offset(src, addr);
2126 if (!src_pte)
2127 continue;
Andi Kleena5516432008-07-23 21:27:41 -07002128 dst_pte = huge_pte_alloc(dst, addr, sz);
David Gibson63551ae2005-06-21 17:14:44 -07002129 if (!dst_pte)
2130 goto nomem;
Larry Woodmanc5c99422008-01-24 05:49:25 -08002131
2132 /* If the pagetables are shared don't copy or take references */
2133 if (dst_pte == src_pte)
2134 continue;
2135
Hugh Dickinsc74df322005-10-29 18:16:23 -07002136 spin_lock(&dst->page_table_lock);
Nick Piggin46478752008-06-05 22:45:57 -07002137 spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING);
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002138 if (!huge_pte_none(huge_ptep_get(src_pte))) {
David Gibson1e8f8892006-01-06 00:10:44 -08002139 if (cow)
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002140 huge_ptep_set_wrprotect(src, addr, src_pte);
2141 entry = huge_ptep_get(src_pte);
Hugh Dickins1c598272005-10-19 21:23:43 -07002142 ptepage = pte_page(entry);
2143 get_page(ptepage);
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002144 page_dup_rmap(ptepage);
Hugh Dickins1c598272005-10-19 21:23:43 -07002145 set_huge_pte_at(dst, addr, dst_pte, entry);
2146 }
2147 spin_unlock(&src->page_table_lock);
Hugh Dickinsc74df322005-10-29 18:16:23 -07002148 spin_unlock(&dst->page_table_lock);
David Gibson63551ae2005-06-21 17:14:44 -07002149 }
2150 return 0;
2151
2152nomem:
2153 return -ENOMEM;
2154}
2155
Naoya Horiguchifd6a03e2010-05-28 09:29:21 +09002156static int is_hugetlb_entry_hwpoisoned(pte_t pte)
2157{
2158 swp_entry_t swp;
2159
2160 if (huge_pte_none(pte) || pte_present(pte))
2161 return 0;
2162 swp = pte_to_swp_entry(pte);
2163 if (non_swap_entry(swp) && is_hwpoison_entry(swp)) {
2164 return 1;
2165 } else
2166 return 0;
2167}
2168
Chen, Kenneth W502717f2006-10-11 01:20:46 -07002169void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002170 unsigned long end, struct page *ref_page)
David Gibson63551ae2005-06-21 17:14:44 -07002171{
2172 struct mm_struct *mm = vma->vm_mm;
2173 unsigned long address;
David Gibsonc7546f82005-08-05 11:59:35 -07002174 pte_t *ptep;
David Gibson63551ae2005-06-21 17:14:44 -07002175 pte_t pte;
2176 struct page *page;
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07002177 struct page *tmp;
Andi Kleena5516432008-07-23 21:27:41 -07002178 struct hstate *h = hstate_vma(vma);
2179 unsigned long sz = huge_page_size(h);
2180
Chen, Kenneth Wc0a499c2006-12-06 20:31:39 -08002181 /*
2182 * A page gathering list, protected by per file i_mmap_lock. The
2183 * lock is used to avoid list corruption from multiple unmapping
2184 * of the same page since we are using page->lru.
2185 */
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07002186 LIST_HEAD(page_list);
David Gibson63551ae2005-06-21 17:14:44 -07002187
2188 WARN_ON(!is_vm_hugetlb_page(vma));
Andi Kleena5516432008-07-23 21:27:41 -07002189 BUG_ON(start & ~huge_page_mask(h));
2190 BUG_ON(end & ~huge_page_mask(h));
David Gibson63551ae2005-06-21 17:14:44 -07002191
Andrea Arcangelicddb8a52008-07-28 15:46:29 -07002192 mmu_notifier_invalidate_range_start(mm, start, end);
Hugh Dickins508034a2005-10-29 18:16:30 -07002193 spin_lock(&mm->page_table_lock);
Andi Kleena5516432008-07-23 21:27:41 -07002194 for (address = start; address < end; address += sz) {
David Gibsonc7546f82005-08-05 11:59:35 -07002195 ptep = huge_pte_offset(mm, address);
Adam Litke4c887262005-10-29 18:16:46 -07002196 if (!ptep)
David Gibsonc7546f82005-08-05 11:59:35 -07002197 continue;
2198
Chen, Kenneth W39dde652006-12-06 20:32:03 -08002199 if (huge_pmd_unshare(mm, &address, ptep))
2200 continue;
2201
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002202 /*
2203 * If a reference page is supplied, it is because a specific
2204 * page is being unmapped, not a range. Ensure the page we
2205 * are about to unmap is the actual page of interest.
2206 */
2207 if (ref_page) {
2208 pte = huge_ptep_get(ptep);
2209 if (huge_pte_none(pte))
2210 continue;
2211 page = pte_page(pte);
2212 if (page != ref_page)
2213 continue;
2214
2215 /*
2216 * Mark the VMA as having unmapped its page so that
2217 * future faults in this VMA will fail rather than
2218 * looking like data was lost
2219 */
2220 set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED);
2221 }
2222
David Gibsonc7546f82005-08-05 11:59:35 -07002223 pte = huge_ptep_get_and_clear(mm, address, ptep);
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002224 if (huge_pte_none(pte))
David Gibson63551ae2005-06-21 17:14:44 -07002225 continue;
David Gibsonc7546f82005-08-05 11:59:35 -07002226
Naoya Horiguchifd6a03e2010-05-28 09:29:21 +09002227 /*
2228 * HWPoisoned hugepage is already unmapped and dropped reference
2229 */
2230 if (unlikely(is_hugetlb_entry_hwpoisoned(pte)))
2231 continue;
2232
David Gibson63551ae2005-06-21 17:14:44 -07002233 page = pte_page(pte);
Ken Chen6649a382007-02-08 14:20:27 -08002234 if (pte_dirty(pte))
2235 set_page_dirty(page);
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07002236 list_add(&page->lru, &page_list);
David Gibson63551ae2005-06-21 17:14:44 -07002237 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002238 spin_unlock(&mm->page_table_lock);
Hugh Dickins508034a2005-10-29 18:16:30 -07002239 flush_tlb_range(vma, start, end);
Andrea Arcangelicddb8a52008-07-28 15:46:29 -07002240 mmu_notifier_invalidate_range_end(mm, start, end);
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07002241 list_for_each_entry_safe(page, tmp, &page_list, lru) {
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002242 page_remove_rmap(page);
Chen, Kenneth Wfe1668a2006-10-04 02:15:24 -07002243 list_del(&page->lru);
2244 put_page(page);
2245 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002246}
David Gibson63551ae2005-06-21 17:14:44 -07002247
Chen, Kenneth W502717f2006-10-11 01:20:46 -07002248void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002249 unsigned long end, struct page *ref_page)
Chen, Kenneth W502717f2006-10-11 01:20:46 -07002250{
Andi Kleena137e1c2008-07-23 21:27:43 -07002251 spin_lock(&vma->vm_file->f_mapping->i_mmap_lock);
2252 __unmap_hugepage_range(vma, start, end, ref_page);
2253 spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock);
Chen, Kenneth W502717f2006-10-11 01:20:46 -07002254}
2255
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002256/*
2257 * This is called when the original mapper is failing to COW a MAP_PRIVATE
2258 * mappping it owns the reserve page for. The intention is to unmap the page
2259 * from other VMAs and let the children be SIGKILLed if they are faulting the
2260 * same region.
2261 */
Harvey Harrison2a4b3de2008-10-18 20:27:06 -07002262static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
2263 struct page *page, unsigned long address)
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002264{
Adam Litke75266742008-11-12 13:24:56 -08002265 struct hstate *h = hstate_vma(vma);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002266 struct vm_area_struct *iter_vma;
2267 struct address_space *mapping;
2268 struct prio_tree_iter iter;
2269 pgoff_t pgoff;
2270
2271 /*
2272 * vm_pgoff is in PAGE_SIZE units, hence the different calculation
2273 * from page cache lookup which is in HPAGE_SIZE units.
2274 */
Adam Litke75266742008-11-12 13:24:56 -08002275 address = address & huge_page_mask(h);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002276 pgoff = ((address - vma->vm_start) >> PAGE_SHIFT)
2277 + (vma->vm_pgoff >> PAGE_SHIFT);
2278 mapping = (struct address_space *)page_private(page);
2279
Mel Gorman4eb2b1d2009-12-14 17:59:53 -08002280 /*
2281 * Take the mapping lock for the duration of the table walk. As
2282 * this mapping should be shared between all the VMAs,
2283 * __unmap_hugepage_range() is called as the lock is already held
2284 */
2285 spin_lock(&mapping->i_mmap_lock);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002286 vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
2287 /* Do not unmap the current VMA */
2288 if (iter_vma == vma)
2289 continue;
2290
2291 /*
2292 * Unmap the page from other VMAs without their own reserves.
2293 * They get marked to be SIGKILLed if they fault in these
2294 * areas. This is because a future no-page fault on this VMA
2295 * could insert a zeroed page instead of the data existing
2296 * from the time of fork. This would look like data corruption
2297 */
2298 if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER))
Mel Gorman4eb2b1d2009-12-14 17:59:53 -08002299 __unmap_hugepage_range(iter_vma,
Adam Litke75266742008-11-12 13:24:56 -08002300 address, address + huge_page_size(h),
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002301 page);
2302 }
Mel Gorman4eb2b1d2009-12-14 17:59:53 -08002303 spin_unlock(&mapping->i_mmap_lock);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002304
2305 return 1;
2306}
2307
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002308/*
2309 * Hugetlb_cow() should be called with page lock of the original hugepage held.
2310 */
David Gibson1e8f8892006-01-06 00:10:44 -08002311static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002312 unsigned long address, pte_t *ptep, pte_t pte,
2313 struct page *pagecache_page)
David Gibson1e8f8892006-01-06 00:10:44 -08002314{
Andi Kleena5516432008-07-23 21:27:41 -07002315 struct hstate *h = hstate_vma(vma);
David Gibson1e8f8892006-01-06 00:10:44 -08002316 struct page *old_page, *new_page;
David Gibson79ac6ba2006-03-22 00:08:51 -08002317 int avoidcopy;
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002318 int outside_reserve = 0;
David Gibson1e8f8892006-01-06 00:10:44 -08002319
2320 old_page = pte_page(pte);
2321
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002322retry_avoidcopy:
David Gibson1e8f8892006-01-06 00:10:44 -08002323 /* If no-one else is actually using this page, avoid the copy
2324 * and just make the page writable */
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002325 avoidcopy = (page_mapcount(old_page) == 1);
David Gibson1e8f8892006-01-06 00:10:44 -08002326 if (avoidcopy) {
Naoya Horiguchi56c9cfb2010-09-10 13:23:04 +09002327 if (PageAnon(old_page))
2328 page_move_anon_rmap(old_page, vma, address);
David Gibson1e8f8892006-01-06 00:10:44 -08002329 set_huge_ptep_writable(vma, address, ptep);
Nick Piggin83c54072007-07-19 01:47:05 -07002330 return 0;
David Gibson1e8f8892006-01-06 00:10:44 -08002331 }
2332
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002333 /*
2334 * If the process that created a MAP_PRIVATE mapping is about to
2335 * perform a COW due to a shared page count, attempt to satisfy
2336 * the allocation without using the existing reserves. The pagecache
2337 * page is used to determine if the reserve at this address was
2338 * consumed or not. If reserves were used, a partial faulted mapping
2339 * at the time of fork() could consume its reserves on COW instead
2340 * of the full address range.
2341 */
Mel Gormanf83a2752009-05-28 14:34:40 -07002342 if (!(vma->vm_flags & VM_MAYSHARE) &&
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002343 is_vma_resv_set(vma, HPAGE_RESV_OWNER) &&
2344 old_page != pagecache_page)
2345 outside_reserve = 1;
2346
David Gibson1e8f8892006-01-06 00:10:44 -08002347 page_cache_get(old_page);
Larry Woodmanb76c8cf2009-12-14 17:59:37 -08002348
2349 /* Drop page_table_lock as buddy allocator may be called */
2350 spin_unlock(&mm->page_table_lock);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002351 new_page = alloc_huge_page(vma, address, outside_reserve);
David Gibson1e8f8892006-01-06 00:10:44 -08002352
Adam Litke2fc39ce2007-11-14 16:59:39 -08002353 if (IS_ERR(new_page)) {
David Gibson1e8f8892006-01-06 00:10:44 -08002354 page_cache_release(old_page);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002355
2356 /*
2357 * If a process owning a MAP_PRIVATE mapping fails to COW,
2358 * it is due to references held by a child and an insufficient
2359 * huge page pool. To guarantee the original mappers
2360 * reliability, unmap the page from child processes. The child
2361 * may get SIGKILLed if it later faults.
2362 */
2363 if (outside_reserve) {
2364 BUG_ON(huge_pte_none(pte));
2365 if (unmap_ref_private(mm, vma, old_page, address)) {
2366 BUG_ON(page_count(old_page) != 1);
2367 BUG_ON(huge_pte_none(pte));
Larry Woodmanb76c8cf2009-12-14 17:59:37 -08002368 spin_lock(&mm->page_table_lock);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002369 goto retry_avoidcopy;
2370 }
2371 WARN_ON_ONCE(1);
2372 }
2373
Larry Woodmanb76c8cf2009-12-14 17:59:37 -08002374 /* Caller expects lock to be held */
2375 spin_lock(&mm->page_table_lock);
Adam Litke2fc39ce2007-11-14 16:59:39 -08002376 return -PTR_ERR(new_page);
David Gibson1e8f8892006-01-06 00:10:44 -08002377 }
2378
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002379 /*
2380 * When the original hugepage is shared one, it does not have
2381 * anon_vma prepared.
2382 */
2383 if (unlikely(anon_vma_prepare(vma)))
2384 return VM_FAULT_OOM;
2385
Atsushi Nemoto9de455b2006-12-12 17:14:55 +00002386 copy_huge_page(new_page, old_page, address, vma);
Nick Piggin0ed361d2008-02-04 22:29:34 -08002387 __SetPageUptodate(new_page);
David Gibson1e8f8892006-01-06 00:10:44 -08002388
Larry Woodmanb76c8cf2009-12-14 17:59:37 -08002389 /*
2390 * Retake the page_table_lock to check for racing updates
2391 * before the page tables are altered
2392 */
2393 spin_lock(&mm->page_table_lock);
Andi Kleena5516432008-07-23 21:27:41 -07002394 ptep = huge_pte_offset(mm, address & huge_page_mask(h));
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002395 if (likely(pte_same(huge_ptep_get(ptep), pte))) {
David Gibson1e8f8892006-01-06 00:10:44 -08002396 /* Break COW */
Doug Doan3edd4fc2010-08-09 17:18:30 -07002397 mmu_notifier_invalidate_range_start(mm,
2398 address & huge_page_mask(h),
2399 (address & huge_page_mask(h)) + huge_page_size(h));
Gerald Schaefer8fe627e2008-04-28 02:13:28 -07002400 huge_ptep_clear_flush(vma, address, ptep);
David Gibson1e8f8892006-01-06 00:10:44 -08002401 set_huge_pte_at(mm, address, ptep,
2402 make_huge_pte(vma, new_page, 1));
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002403 page_remove_rmap(old_page);
Naoya Horiguchicd67f0d2010-09-10 13:23:04 +09002404 hugepage_add_new_anon_rmap(new_page, vma, address);
David Gibson1e8f8892006-01-06 00:10:44 -08002405 /* Make the old page be freed below */
2406 new_page = old_page;
Doug Doan3edd4fc2010-08-09 17:18:30 -07002407 mmu_notifier_invalidate_range_end(mm,
2408 address & huge_page_mask(h),
2409 (address & huge_page_mask(h)) + huge_page_size(h));
David Gibson1e8f8892006-01-06 00:10:44 -08002410 }
2411 page_cache_release(new_page);
2412 page_cache_release(old_page);
Nick Piggin83c54072007-07-19 01:47:05 -07002413 return 0;
David Gibson1e8f8892006-01-06 00:10:44 -08002414}
2415
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002416/* Return the pagecache page at a given address within a VMA */
Andi Kleena5516432008-07-23 21:27:41 -07002417static struct page *hugetlbfs_pagecache_page(struct hstate *h,
2418 struct vm_area_struct *vma, unsigned long address)
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002419{
2420 struct address_space *mapping;
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -07002421 pgoff_t idx;
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002422
2423 mapping = vma->vm_file->f_mapping;
Andi Kleena5516432008-07-23 21:27:41 -07002424 idx = vma_hugecache_offset(h, vma, address);
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002425
2426 return find_lock_page(mapping, idx);
2427}
2428
Hugh Dickins3ae77f42009-09-21 17:03:33 -07002429/*
2430 * Return whether there is a pagecache page to back given address within VMA.
2431 * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page.
2432 */
2433static bool hugetlbfs_pagecache_present(struct hstate *h,
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002434 struct vm_area_struct *vma, unsigned long address)
2435{
2436 struct address_space *mapping;
2437 pgoff_t idx;
2438 struct page *page;
2439
2440 mapping = vma->vm_file->f_mapping;
2441 idx = vma_hugecache_offset(h, vma, address);
2442
2443 page = find_get_page(mapping, idx);
2444 if (page)
2445 put_page(page);
2446 return page != NULL;
2447}
2448
Robert P. J. Daya1ed3dd2007-07-17 04:03:33 -07002449static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
Hugh Dickins788c7df2009-06-23 13:49:05 +01002450 unsigned long address, pte_t *ptep, unsigned int flags)
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01002451{
Andi Kleena5516432008-07-23 21:27:41 -07002452 struct hstate *h = hstate_vma(vma);
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01002453 int ret = VM_FAULT_SIGBUS;
Andy Whitcrofte7c4b0b2008-07-23 21:27:26 -07002454 pgoff_t idx;
Adam Litke4c887262005-10-29 18:16:46 -07002455 unsigned long size;
Adam Litke4c887262005-10-29 18:16:46 -07002456 struct page *page;
2457 struct address_space *mapping;
David Gibson1e8f8892006-01-06 00:10:44 -08002458 pte_t new_pte;
Adam Litke4c887262005-10-29 18:16:46 -07002459
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002460 /*
2461 * Currently, we are forced to kill the process in the event the
2462 * original mapper has unmapped pages from the child due to a failed
2463 * COW. Warn that such a situation has occured as it may not be obvious
2464 */
2465 if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) {
2466 printk(KERN_WARNING
2467 "PID %d killed due to inadequate hugepage pool\n",
2468 current->pid);
2469 return ret;
2470 }
2471
Adam Litke4c887262005-10-29 18:16:46 -07002472 mapping = vma->vm_file->f_mapping;
Andi Kleena5516432008-07-23 21:27:41 -07002473 idx = vma_hugecache_offset(h, vma, address);
Adam Litke4c887262005-10-29 18:16:46 -07002474
2475 /*
2476 * Use page lock to guard against racing truncation
2477 * before we get page_table_lock.
2478 */
Christoph Lameter6bda6662006-01-06 00:10:49 -08002479retry:
2480 page = find_lock_page(mapping, idx);
2481 if (!page) {
Andi Kleena5516432008-07-23 21:27:41 -07002482 size = i_size_read(mapping->host) >> huge_page_shift(h);
Hugh Dickinsebed4bf2006-10-28 10:38:43 -07002483 if (idx >= size)
2484 goto out;
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002485 page = alloc_huge_page(vma, address, 0);
Adam Litke2fc39ce2007-11-14 16:59:39 -08002486 if (IS_ERR(page)) {
2487 ret = -PTR_ERR(page);
Christoph Lameter6bda6662006-01-06 00:10:49 -08002488 goto out;
2489 }
Andi Kleena5516432008-07-23 21:27:41 -07002490 clear_huge_page(page, address, huge_page_size(h));
Nick Piggin0ed361d2008-02-04 22:29:34 -08002491 __SetPageUptodate(page);
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01002492
Mel Gormanf83a2752009-05-28 14:34:40 -07002493 if (vma->vm_flags & VM_MAYSHARE) {
Christoph Lameter6bda6662006-01-06 00:10:49 -08002494 int err;
Ken Chen45c682a2007-11-14 16:59:44 -08002495 struct inode *inode = mapping->host;
Christoph Lameter6bda6662006-01-06 00:10:49 -08002496
2497 err = add_to_page_cache(page, mapping, idx, GFP_KERNEL);
2498 if (err) {
2499 put_page(page);
Christoph Lameter6bda6662006-01-06 00:10:49 -08002500 if (err == -EEXIST)
2501 goto retry;
2502 goto out;
2503 }
Ken Chen45c682a2007-11-14 16:59:44 -08002504
2505 spin_lock(&inode->i_lock);
Andi Kleena5516432008-07-23 21:27:41 -07002506 inode->i_blocks += blocks_per_huge_page(h);
Ken Chen45c682a2007-11-14 16:59:44 -08002507 spin_unlock(&inode->i_lock);
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002508 page_dup_rmap(page);
Mel Gorman23be7462010-04-23 13:17:56 -04002509 } else {
Christoph Lameter6bda6662006-01-06 00:10:49 -08002510 lock_page(page);
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002511 if (unlikely(anon_vma_prepare(vma))) {
2512 ret = VM_FAULT_OOM;
2513 goto backout_unlocked;
2514 }
2515 hugepage_add_new_anon_rmap(page, vma, address);
Mel Gorman23be7462010-04-23 13:17:56 -04002516 }
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002517 } else {
2518 page_dup_rmap(page);
Christoph Lameter6bda6662006-01-06 00:10:49 -08002519 }
David Gibson1e8f8892006-01-06 00:10:44 -08002520
Andy Whitcroft57303d82008-08-12 15:08:47 -07002521 /*
Naoya Horiguchifd6a03e2010-05-28 09:29:21 +09002522 * Since memory error handler replaces pte into hwpoison swap entry
2523 * at the time of error handling, a process which reserved but not have
2524 * the mapping to the error hugepage does not have hwpoison swap entry.
2525 * So we need to block accesses from such a process by checking
2526 * PG_hwpoison bit here.
2527 */
2528 if (unlikely(PageHWPoison(page))) {
2529 ret = VM_FAULT_HWPOISON;
2530 goto backout_unlocked;
David Gibson63551ae2005-06-21 17:14:44 -07002531 }
2532
Andy Whitcroft57303d82008-08-12 15:08:47 -07002533 /*
2534 * If we are going to COW a private mapping later, we examine the
2535 * pending reservations for this page now. This will ensure that
2536 * any allocations necessary to record that reservation occur outside
2537 * the spinlock.
2538 */
Hugh Dickins788c7df2009-06-23 13:49:05 +01002539 if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED))
Andy Whitcroft2b267362008-08-12 15:08:49 -07002540 if (vma_needs_reservation(h, vma, address) < 0) {
2541 ret = VM_FAULT_OOM;
2542 goto backout_unlocked;
2543 }
Andy Whitcroft57303d82008-08-12 15:08:47 -07002544
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01002545 spin_lock(&mm->page_table_lock);
Andi Kleena5516432008-07-23 21:27:41 -07002546 size = i_size_read(mapping->host) >> huge_page_shift(h);
Adam Litke4c887262005-10-29 18:16:46 -07002547 if (idx >= size)
2548 goto backout;
2549
Nick Piggin83c54072007-07-19 01:47:05 -07002550 ret = 0;
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002551 if (!huge_pte_none(huge_ptep_get(ptep)))
Adam Litke4c887262005-10-29 18:16:46 -07002552 goto backout;
2553
David Gibson1e8f8892006-01-06 00:10:44 -08002554 new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE)
2555 && (vma->vm_flags & VM_SHARED)));
2556 set_huge_pte_at(mm, address, ptep, new_pte);
2557
Hugh Dickins788c7df2009-06-23 13:49:05 +01002558 if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
David Gibson1e8f8892006-01-06 00:10:44 -08002559 /* Optimization, do the COW without a second fault */
Mel Gorman04f2cbe2008-07-23 21:27:25 -07002560 ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page);
David Gibson1e8f8892006-01-06 00:10:44 -08002561 }
2562
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01002563 spin_unlock(&mm->page_table_lock);
Adam Litke4c887262005-10-29 18:16:46 -07002564 unlock_page(page);
2565out:
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01002566 return ret;
Adam Litke4c887262005-10-29 18:16:46 -07002567
2568backout:
2569 spin_unlock(&mm->page_table_lock);
Andy Whitcroft2b267362008-08-12 15:08:49 -07002570backout_unlocked:
Adam Litke4c887262005-10-29 18:16:46 -07002571 unlock_page(page);
2572 put_page(page);
2573 goto out;
Hugh Dickinsac9b9c62005-10-20 16:24:28 +01002574}
2575
Adam Litke86e52162006-01-06 00:10:43 -08002576int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
Hugh Dickins788c7df2009-06-23 13:49:05 +01002577 unsigned long address, unsigned int flags)
Adam Litke86e52162006-01-06 00:10:43 -08002578{
2579 pte_t *ptep;
2580 pte_t entry;
David Gibson1e8f8892006-01-06 00:10:44 -08002581 int ret;
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002582 struct page *page = NULL;
Andy Whitcroft57303d82008-08-12 15:08:47 -07002583 struct page *pagecache_page = NULL;
David Gibson3935baa2006-03-22 00:08:53 -08002584 static DEFINE_MUTEX(hugetlb_instantiation_mutex);
Andi Kleena5516432008-07-23 21:27:41 -07002585 struct hstate *h = hstate_vma(vma);
Adam Litke86e52162006-01-06 00:10:43 -08002586
Naoya Horiguchifd6a03e2010-05-28 09:29:21 +09002587 ptep = huge_pte_offset(mm, address);
2588 if (ptep) {
2589 entry = huge_ptep_get(ptep);
2590 if (unlikely(is_hugetlb_entry_hwpoisoned(entry)))
2591 return VM_FAULT_HWPOISON;
2592 }
2593
Andi Kleena5516432008-07-23 21:27:41 -07002594 ptep = huge_pte_alloc(mm, address, huge_page_size(h));
Adam Litke86e52162006-01-06 00:10:43 -08002595 if (!ptep)
2596 return VM_FAULT_OOM;
2597
David Gibson3935baa2006-03-22 00:08:53 -08002598 /*
2599 * Serialize hugepage allocation and instantiation, so that we don't
2600 * get spurious allocation failures if two CPUs race to instantiate
2601 * the same page in the page cache.
2602 */
2603 mutex_lock(&hugetlb_instantiation_mutex);
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002604 entry = huge_ptep_get(ptep);
2605 if (huge_pte_none(entry)) {
Hugh Dickins788c7df2009-06-23 13:49:05 +01002606 ret = hugetlb_no_page(mm, vma, address, ptep, flags);
David Gibsonb4d1d992008-10-15 22:01:11 -07002607 goto out_mutex;
David Gibson3935baa2006-03-22 00:08:53 -08002608 }
Adam Litke86e52162006-01-06 00:10:43 -08002609
Nick Piggin83c54072007-07-19 01:47:05 -07002610 ret = 0;
David Gibson1e8f8892006-01-06 00:10:44 -08002611
Andy Whitcroft57303d82008-08-12 15:08:47 -07002612 /*
2613 * If we are going to COW the mapping later, we examine the pending
2614 * reservations for this page now. This will ensure that any
2615 * allocations necessary to record that reservation occur outside the
2616 * spinlock. For private mappings, we also lookup the pagecache
2617 * page now as it is used to determine if a reservation has been
2618 * consumed.
2619 */
Hugh Dickins788c7df2009-06-23 13:49:05 +01002620 if ((flags & FAULT_FLAG_WRITE) && !pte_write(entry)) {
Andy Whitcroft2b267362008-08-12 15:08:49 -07002621 if (vma_needs_reservation(h, vma, address) < 0) {
2622 ret = VM_FAULT_OOM;
David Gibsonb4d1d992008-10-15 22:01:11 -07002623 goto out_mutex;
Andy Whitcroft2b267362008-08-12 15:08:49 -07002624 }
Andy Whitcroft57303d82008-08-12 15:08:47 -07002625
Mel Gormanf83a2752009-05-28 14:34:40 -07002626 if (!(vma->vm_flags & VM_MAYSHARE))
Andy Whitcroft57303d82008-08-12 15:08:47 -07002627 pagecache_page = hugetlbfs_pagecache_page(h,
2628 vma, address);
2629 }
2630
Naoya Horiguchi56c9cfb2010-09-10 13:23:04 +09002631 /*
2632 * hugetlb_cow() requires page locks of pte_page(entry) and
2633 * pagecache_page, so here we need take the former one
2634 * when page != pagecache_page or !pagecache_page.
2635 * Note that locking order is always pagecache_page -> page,
2636 * so no worry about deadlock.
2637 */
2638 page = pte_page(entry);
2639 if (page != pagecache_page)
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002640 lock_page(page);
Naoya Horiguchi0fe6e202010-05-28 09:29:16 +09002641
David Gibson1e8f8892006-01-06 00:10:44 -08002642 spin_lock(&mm->page_table_lock);
2643 /* Check for a racing update before calling hugetlb_cow */
David Gibsonb4d1d992008-10-15 22:01:11 -07002644 if (unlikely(!pte_same(entry, huge_ptep_get(ptep))))
2645 goto out_page_table_lock;
2646
2647
Hugh Dickins788c7df2009-06-23 13:49:05 +01002648 if (flags & FAULT_FLAG_WRITE) {
David Gibsonb4d1d992008-10-15 22:01:11 -07002649 if (!pte_write(entry)) {
Andy Whitcroft57303d82008-08-12 15:08:47 -07002650 ret = hugetlb_cow(mm, vma, address, ptep, entry,
2651 pagecache_page);
David Gibsonb4d1d992008-10-15 22:01:11 -07002652 goto out_page_table_lock;
2653 }
2654 entry = pte_mkdirty(entry);
2655 }
2656 entry = pte_mkyoung(entry);
Hugh Dickins788c7df2009-06-23 13:49:05 +01002657 if (huge_ptep_set_access_flags(vma, address, ptep, entry,
2658 flags & FAULT_FLAG_WRITE))
Russell King4b3073e2009-12-18 16:40:18 +00002659 update_mmu_cache(vma, address, ptep);
David Gibsonb4d1d992008-10-15 22:01:11 -07002660
2661out_page_table_lock:
David Gibson1e8f8892006-01-06 00:10:44 -08002662 spin_unlock(&mm->page_table_lock);
Andy Whitcroft57303d82008-08-12 15:08:47 -07002663
2664 if (pagecache_page) {
2665 unlock_page(pagecache_page);
2666 put_page(pagecache_page);
2667 }
Naoya Horiguchi56c9cfb2010-09-10 13:23:04 +09002668 unlock_page(page);
Andy Whitcroft57303d82008-08-12 15:08:47 -07002669
David Gibsonb4d1d992008-10-15 22:01:11 -07002670out_mutex:
David Gibson3935baa2006-03-22 00:08:53 -08002671 mutex_unlock(&hugetlb_instantiation_mutex);
David Gibson1e8f8892006-01-06 00:10:44 -08002672
2673 return ret;
Adam Litke86e52162006-01-06 00:10:43 -08002674}
2675
Andi Kleenceb86872008-07-23 21:27:50 -07002676/* Can be overriden by architectures */
2677__attribute__((weak)) struct page *
2678follow_huge_pud(struct mm_struct *mm, unsigned long address,
2679 pud_t *pud, int write)
2680{
2681 BUG();
2682 return NULL;
2683}
2684
David Gibson63551ae2005-06-21 17:14:44 -07002685int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
2686 struct page **pages, struct vm_area_struct **vmas,
Adam Litke5b23dbe2007-11-14 16:59:33 -08002687 unsigned long *position, int *length, int i,
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002688 unsigned int flags)
David Gibson63551ae2005-06-21 17:14:44 -07002689{
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002690 unsigned long pfn_offset;
2691 unsigned long vaddr = *position;
David Gibson63551ae2005-06-21 17:14:44 -07002692 int remainder = *length;
Andi Kleena5516432008-07-23 21:27:41 -07002693 struct hstate *h = hstate_vma(vma);
David Gibson63551ae2005-06-21 17:14:44 -07002694
Hugh Dickins1c598272005-10-19 21:23:43 -07002695 spin_lock(&mm->page_table_lock);
David Gibson63551ae2005-06-21 17:14:44 -07002696 while (vaddr < vma->vm_end && remainder) {
Adam Litke4c887262005-10-29 18:16:46 -07002697 pte_t *pte;
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002698 int absent;
Adam Litke4c887262005-10-29 18:16:46 -07002699 struct page *page;
2700
2701 /*
2702 * Some archs (sparc64, sh*) have multiple pte_ts to
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002703 * each hugepage. We have to make sure we get the
Adam Litke4c887262005-10-29 18:16:46 -07002704 * first, for the page indexing below to work.
2705 */
Andi Kleena5516432008-07-23 21:27:41 -07002706 pte = huge_pte_offset(mm, vaddr & huge_page_mask(h));
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002707 absent = !pte || huge_pte_none(huge_ptep_get(pte));
Adam Litke4c887262005-10-29 18:16:46 -07002708
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002709 /*
2710 * When coredumping, it suits get_dump_page if we just return
Hugh Dickins3ae77f42009-09-21 17:03:33 -07002711 * an error where there's an empty slot with no huge pagecache
2712 * to back it. This way, we avoid allocating a hugepage, and
2713 * the sparse dumpfile avoids allocating disk blocks, but its
2714 * huge holes still show up with zeroes where they need to be.
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002715 */
Hugh Dickins3ae77f42009-09-21 17:03:33 -07002716 if (absent && (flags & FOLL_DUMP) &&
2717 !hugetlbfs_pagecache_present(h, vma, vaddr)) {
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002718 remainder = 0;
2719 break;
2720 }
2721
2722 if (absent ||
2723 ((flags & FOLL_WRITE) && !pte_write(huge_ptep_get(pte)))) {
Adam Litke4c887262005-10-29 18:16:46 -07002724 int ret;
2725
2726 spin_unlock(&mm->page_table_lock);
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002727 ret = hugetlb_fault(mm, vma, vaddr,
2728 (flags & FOLL_WRITE) ? FAULT_FLAG_WRITE : 0);
Adam Litke4c887262005-10-29 18:16:46 -07002729 spin_lock(&mm->page_table_lock);
Adam Litkea89182c2007-08-22 14:01:51 -07002730 if (!(ret & VM_FAULT_ERROR))
Adam Litke4c887262005-10-29 18:16:46 -07002731 continue;
2732
2733 remainder = 0;
Adam Litke4c887262005-10-29 18:16:46 -07002734 break;
2735 }
David Gibson63551ae2005-06-21 17:14:44 -07002736
Andi Kleena5516432008-07-23 21:27:41 -07002737 pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT;
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002738 page = pte_page(huge_ptep_get(pte));
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002739same_page:
Chen, Kenneth Wd6692182006-03-31 02:29:57 -08002740 if (pages) {
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002741 pages[i] = mem_map_offset(page, pfn_offset);
KOSAKI Motohiro4b2e38a2008-10-18 20:27:10 -07002742 get_page(pages[i]);
Chen, Kenneth Wd6692182006-03-31 02:29:57 -08002743 }
David Gibson63551ae2005-06-21 17:14:44 -07002744
2745 if (vmas)
2746 vmas[i] = vma;
2747
2748 vaddr += PAGE_SIZE;
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002749 ++pfn_offset;
David Gibson63551ae2005-06-21 17:14:44 -07002750 --remainder;
2751 ++i;
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002752 if (vaddr < vma->vm_end && remainder &&
Andi Kleena5516432008-07-23 21:27:41 -07002753 pfn_offset < pages_per_huge_page(h)) {
Chen, Kenneth Wd5d4b0a2006-03-22 00:09:03 -08002754 /*
2755 * We use pfn_offset to avoid touching the pageframes
2756 * of this compound page.
2757 */
2758 goto same_page;
2759 }
David Gibson63551ae2005-06-21 17:14:44 -07002760 }
Hugh Dickins1c598272005-10-19 21:23:43 -07002761 spin_unlock(&mm->page_table_lock);
David Gibson63551ae2005-06-21 17:14:44 -07002762 *length = remainder;
2763 *position = vaddr;
2764
Hugh Dickins2a15efc2009-09-21 17:03:27 -07002765 return i ? i : -EFAULT;
David Gibson63551ae2005-06-21 17:14:44 -07002766}
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002767
2768void hugetlb_change_protection(struct vm_area_struct *vma,
2769 unsigned long address, unsigned long end, pgprot_t newprot)
2770{
2771 struct mm_struct *mm = vma->vm_mm;
2772 unsigned long start = address;
2773 pte_t *ptep;
2774 pte_t pte;
Andi Kleena5516432008-07-23 21:27:41 -07002775 struct hstate *h = hstate_vma(vma);
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002776
2777 BUG_ON(address >= end);
2778 flush_cache_range(vma, address, end);
2779
Chen, Kenneth W39dde652006-12-06 20:32:03 -08002780 spin_lock(&vma->vm_file->f_mapping->i_mmap_lock);
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002781 spin_lock(&mm->page_table_lock);
Andi Kleena5516432008-07-23 21:27:41 -07002782 for (; address < end; address += huge_page_size(h)) {
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002783 ptep = huge_pte_offset(mm, address);
2784 if (!ptep)
2785 continue;
Chen, Kenneth W39dde652006-12-06 20:32:03 -08002786 if (huge_pmd_unshare(mm, &address, ptep))
2787 continue;
Gerald Schaefer7f2e9522008-04-28 02:13:29 -07002788 if (!huge_pte_none(huge_ptep_get(ptep))) {
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002789 pte = huge_ptep_get_and_clear(mm, address, ptep);
2790 pte = pte_mkhuge(pte_modify(pte, newprot));
2791 set_huge_pte_at(mm, address, ptep, pte);
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002792 }
2793 }
2794 spin_unlock(&mm->page_table_lock);
Chen, Kenneth W39dde652006-12-06 20:32:03 -08002795 spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock);
Zhang, Yanmin8f860592006-03-22 00:08:50 -08002796
2797 flush_tlb_range(vma, start, end);
2798}
2799
Mel Gormana1e78772008-07-23 21:27:23 -07002800int hugetlb_reserve_pages(struct inode *inode,
2801 long from, long to,
Mel Gorman5a6fe122009-02-10 14:02:27 +00002802 struct vm_area_struct *vma,
2803 int acctflag)
Adam Litkee4e574b2007-10-16 01:26:19 -07002804{
Mel Gorman17c9d122009-02-11 16:34:16 +00002805 long ret, chg;
Andi Kleena5516432008-07-23 21:27:41 -07002806 struct hstate *h = hstate_inode(inode);
Adam Litkee4e574b2007-10-16 01:26:19 -07002807
Mel Gormana1e78772008-07-23 21:27:23 -07002808 /*
Mel Gorman17c9d122009-02-11 16:34:16 +00002809 * Only apply hugepage reservation if asked. At fault time, an
2810 * attempt will be made for VM_NORESERVE to allocate a page
2811 * and filesystem quota without using reserves
2812 */
2813 if (acctflag & VM_NORESERVE)
2814 return 0;
2815
2816 /*
Mel Gormana1e78772008-07-23 21:27:23 -07002817 * Shared mappings base their reservation on the number of pages that
2818 * are already allocated on behalf of the file. Private mappings need
2819 * to reserve the full area even if read-only as mprotect() may be
2820 * called to make the mapping read-write. Assume !vma is a shm mapping
2821 */
Mel Gormanf83a2752009-05-28 14:34:40 -07002822 if (!vma || vma->vm_flags & VM_MAYSHARE)
Mel Gormana1e78772008-07-23 21:27:23 -07002823 chg = region_chg(&inode->i_mapping->private_list, from, to);
Mel Gorman5a6fe122009-02-10 14:02:27 +00002824 else {
2825 struct resv_map *resv_map = resv_map_alloc();
Mel Gorman5a6fe122009-02-10 14:02:27 +00002826 if (!resv_map)
2827 return -ENOMEM;
2828
Mel Gorman17c9d122009-02-11 16:34:16 +00002829 chg = to - from;
2830
Mel Gorman5a6fe122009-02-10 14:02:27 +00002831 set_vma_resv_map(vma, resv_map);
2832 set_vma_resv_flags(vma, HPAGE_RESV_OWNER);
2833 }
2834
Mel Gorman17c9d122009-02-11 16:34:16 +00002835 if (chg < 0)
2836 return chg;
2837
2838 /* There must be enough filesystem quota for the mapping */
2839 if (hugetlb_get_quota(inode->i_mapping, chg))
2840 return -ENOSPC;
2841
2842 /*
2843 * Check enough hugepages are available for the reservation.
2844 * Hand back the quota if there are not
2845 */
2846 ret = hugetlb_acct_memory(h, chg);
2847 if (ret < 0) {
2848 hugetlb_put_quota(inode->i_mapping, chg);
2849 return ret;
2850 }
2851
2852 /*
2853 * Account for the reservations made. Shared mappings record regions
2854 * that have reservations as they are shared by multiple VMAs.
2855 * When the last VMA disappears, the region map says how much
2856 * the reservation was and the page cache tells how much of
2857 * the reservation was consumed. Private mappings are per-VMA and
2858 * only the consumed reservations are tracked. When the VMA
2859 * disappears, the original reservation is the VMA size and the
2860 * consumed reservations are stored in the map. Hence, nothing
2861 * else has to be done for private mappings here
2862 */
Mel Gormanf83a2752009-05-28 14:34:40 -07002863 if (!vma || vma->vm_flags & VM_MAYSHARE)
Mel Gorman17c9d122009-02-11 16:34:16 +00002864 region_add(&inode->i_mapping->private_list, from, to);
Chen, Kenneth Wa43a8c32006-06-23 02:03:15 -07002865 return 0;
2866}
2867
2868void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed)
2869{
Andi Kleena5516432008-07-23 21:27:41 -07002870 struct hstate *h = hstate_inode(inode);
Chen, Kenneth Wa43a8c32006-06-23 02:03:15 -07002871 long chg = region_truncate(&inode->i_mapping->private_list, offset);
Ken Chen45c682a2007-11-14 16:59:44 -08002872
2873 spin_lock(&inode->i_lock);
Eric Sandeene4c6f8b2009-07-29 15:02:16 -07002874 inode->i_blocks -= (blocks_per_huge_page(h) * freed);
Ken Chen45c682a2007-11-14 16:59:44 -08002875 spin_unlock(&inode->i_lock);
2876
Adam Litke90d8b7e2007-11-14 16:59:42 -08002877 hugetlb_put_quota(inode->i_mapping, (chg - freed));
Andi Kleena5516432008-07-23 21:27:41 -07002878 hugetlb_acct_memory(h, -(chg - freed));
Chen, Kenneth Wa43a8c32006-06-23 02:03:15 -07002879}
Naoya Horiguchi93f70f92010-05-28 09:29:20 +09002880
2881/*
2882 * This function is called from memory failure code.
2883 * Assume the caller holds page lock of the head page.
2884 */
2885void __isolate_hwpoisoned_huge_page(struct page *hpage)
2886{
2887 struct hstate *h = page_hstate(hpage);
2888 int nid = page_to_nid(hpage);
2889
2890 spin_lock(&hugetlb_lock);
2891 list_del(&hpage->lru);
2892 h->free_huge_pages--;
2893 h->free_huge_pages_node[nid]--;
2894 spin_unlock(&hugetlb_lock);
2895}