2 * Generic hugetlb support.
3 * (C) Nadia Yvette Chambers, April 2004
5 #include <linux/list.h>
6 #include <linux/init.h>
7 #include <linux/module.h>
9 #include <linux/seq_file.h>
10 #include <linux/sysctl.h>
11 #include <linux/highmem.h>
12 #include <linux/mmu_notifier.h>
13 #include <linux/nodemask.h>
14 #include <linux/pagemap.h>
15 #include <linux/mempolicy.h>
16 #include <linux/compiler.h>
17 #include <linux/cpuset.h>
18 #include <linux/mutex.h>
19 #include <linux/bootmem.h>
20 #include <linux/sysfs.h>
21 #include <linux/slab.h>
22 #include <linux/rmap.h>
23 #include <linux/swap.h>
24 #include <linux/swapops.h>
25 #include <linux/page-isolation.h>
26 #include <linux/jhash.h>
29 #include <asm/pgtable.h>
33 #include <linux/hugetlb.h>
34 #include <linux/hugetlb_cgroup.h>
35 #include <linux/node.h>
38 int hugepages_treat_as_movable
;
40 int hugetlb_max_hstate __read_mostly
;
41 unsigned int default_hstate_idx
;
42 struct hstate hstates
[HUGE_MAX_HSTATE
];
44 * Minimum page order among possible hugepage sizes, set to a proper value
47 static unsigned int minimum_order __read_mostly
= UINT_MAX
;
49 __initdata
LIST_HEAD(huge_boot_pages
);
51 /* for command line parsing */
52 static struct hstate
* __initdata parsed_hstate
;
53 static unsigned long __initdata default_hstate_max_huge_pages
;
54 static unsigned long __initdata default_hstate_size
;
57 * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages,
58 * free_huge_pages, and surplus_huge_pages.
60 DEFINE_SPINLOCK(hugetlb_lock
);
63 * Serializes faults on the same logical page. This is used to
64 * prevent spurious OOMs when the hugepage pool is fully utilized.
66 static int num_fault_mutexes
;
67 static struct mutex
*htlb_fault_mutex_table ____cacheline_aligned_in_smp
;
69 /* Forward declaration */
70 static int hugetlb_acct_memory(struct hstate
*h
, long delta
);
72 static inline void unlock_or_release_subpool(struct hugepage_subpool
*spool
)
74 bool free
= (spool
->count
== 0) && (spool
->used_hpages
== 0);
76 spin_unlock(&spool
->lock
);
78 /* If no pages are used, and no other handles to the subpool
79 * remain, give up any reservations mased on minimum size and
82 if (spool
->min_hpages
!= -1)
83 hugetlb_acct_memory(spool
->hstate
,
89 struct hugepage_subpool
*hugepage_new_subpool(struct hstate
*h
, long max_hpages
,
92 struct hugepage_subpool
*spool
;
94 spool
= kzalloc(sizeof(*spool
), GFP_KERNEL
);
98 spin_lock_init(&spool
->lock
);
100 spool
->max_hpages
= max_hpages
;
102 spool
->min_hpages
= min_hpages
;
104 if (min_hpages
!= -1 && hugetlb_acct_memory(h
, min_hpages
)) {
108 spool
->rsv_hpages
= min_hpages
;
113 void hugepage_put_subpool(struct hugepage_subpool
*spool
)
115 spin_lock(&spool
->lock
);
116 BUG_ON(!spool
->count
);
118 unlock_or_release_subpool(spool
);
122 * Subpool accounting for allocating and reserving pages.
123 * Return -ENOMEM if there are not enough resources to satisfy the
124 * the request. Otherwise, return the number of pages by which the
125 * global pools must be adjusted (upward). The returned value may
126 * only be different than the passed value (delta) in the case where
127 * a subpool minimum size must be manitained.
129 static long hugepage_subpool_get_pages(struct hugepage_subpool
*spool
,
137 spin_lock(&spool
->lock
);
139 if (spool
->max_hpages
!= -1) { /* maximum size accounting */
140 if ((spool
->used_hpages
+ delta
) <= spool
->max_hpages
)
141 spool
->used_hpages
+= delta
;
148 if (spool
->min_hpages
!= -1) { /* minimum size accounting */
149 if (delta
> spool
->rsv_hpages
) {
151 * Asking for more reserves than those already taken on
152 * behalf of subpool. Return difference.
154 ret
= delta
- spool
->rsv_hpages
;
155 spool
->rsv_hpages
= 0;
157 ret
= 0; /* reserves already accounted for */
158 spool
->rsv_hpages
-= delta
;
163 spin_unlock(&spool
->lock
);
168 * Subpool accounting for freeing and unreserving pages.
169 * Return the number of global page reservations that must be dropped.
170 * The return value may only be different than the passed value (delta)
171 * in the case where a subpool minimum size must be maintained.
173 static long hugepage_subpool_put_pages(struct hugepage_subpool
*spool
,
181 spin_lock(&spool
->lock
);
183 if (spool
->max_hpages
!= -1) /* maximum size accounting */
184 spool
->used_hpages
-= delta
;
186 if (spool
->min_hpages
!= -1) { /* minimum size accounting */
187 if (spool
->rsv_hpages
+ delta
<= spool
->min_hpages
)
190 ret
= spool
->rsv_hpages
+ delta
- spool
->min_hpages
;
192 spool
->rsv_hpages
+= delta
;
193 if (spool
->rsv_hpages
> spool
->min_hpages
)
194 spool
->rsv_hpages
= spool
->min_hpages
;
198 * If hugetlbfs_put_super couldn't free spool due to an outstanding
199 * quota reference, free it now.
201 unlock_or_release_subpool(spool
);
206 static inline struct hugepage_subpool
*subpool_inode(struct inode
*inode
)
208 return HUGETLBFS_SB(inode
->i_sb
)->spool
;
211 static inline struct hugepage_subpool
*subpool_vma(struct vm_area_struct
*vma
)
213 return subpool_inode(file_inode(vma
->vm_file
));
217 * Region tracking -- allows tracking of reservations and instantiated pages
218 * across the pages in a mapping.
220 * The region data structures are embedded into a resv_map and protected
221 * by a resv_map's lock. The set of regions within the resv_map represent
222 * reservations for huge pages, or huge pages that have already been
223 * instantiated within the map. The from and to elements are huge page
224 * indicies into the associated mapping. from indicates the starting index
225 * of the region. to represents the first index past the end of the region.
227 * For example, a file region structure with from == 0 and to == 4 represents
228 * four huge pages in a mapping. It is important to note that the to element
229 * represents the first element past the end of the region. This is used in
230 * arithmetic as 4(to) - 0(from) = 4 huge pages in the region.
232 * Interval notation of the form [from, to) will be used to indicate that
233 * the endpoint from is inclusive and to is exclusive.
236 struct list_head link
;
242 * Add the huge page range represented by [f, t) to the reserve
243 * map. In the normal case, existing regions will be expanded
244 * to accommodate the specified range. Sufficient regions should
245 * exist for expansion due to the previous call to region_chg
246 * with the same range. However, it is possible that region_del
247 * could have been called after region_chg and modifed the map
248 * in such a way that no region exists to be expanded. In this
249 * case, pull a region descriptor from the cache associated with
250 * the map and use that for the new range.
252 * Return the number of new huge pages added to the map. This
253 * number is greater than or equal to zero.
255 static long region_add(struct resv_map
*resv
, long f
, long t
)
257 struct list_head
*head
= &resv
->regions
;
258 struct file_region
*rg
, *nrg
, *trg
;
261 spin_lock(&resv
->lock
);
262 /* Locate the region we are either in or before. */
263 list_for_each_entry(rg
, head
, link
)
268 * If no region exists which can be expanded to include the
269 * specified range, the list must have been modified by an
270 * interleving call to region_del(). Pull a region descriptor
271 * from the cache and use it for this range.
273 if (&rg
->link
== head
|| t
< rg
->from
) {
274 VM_BUG_ON(resv
->region_cache_count
<= 0);
276 resv
->region_cache_count
--;
277 nrg
= list_first_entry(&resv
->region_cache
, struct file_region
,
279 list_del(&nrg
->link
);
283 list_add(&nrg
->link
, rg
->link
.prev
);
289 /* Round our left edge to the current segment if it encloses us. */
293 /* Check for and consume any regions we now overlap with. */
295 list_for_each_entry_safe(rg
, trg
, rg
->link
.prev
, link
) {
296 if (&rg
->link
== head
)
301 /* If this area reaches higher then extend our area to
302 * include it completely. If this is not the first area
303 * which we intend to reuse, free it. */
307 /* Decrement return value by the deleted range.
308 * Another range will span this area so that by
309 * end of routine add will be >= zero
311 add
-= (rg
->to
- rg
->from
);
317 add
+= (nrg
->from
- f
); /* Added to beginning of region */
319 add
+= t
- nrg
->to
; /* Added to end of region */
323 resv
->adds_in_progress
--;
324 spin_unlock(&resv
->lock
);
330 * Examine the existing reserve map and determine how many
331 * huge pages in the specified range [f, t) are NOT currently
332 * represented. This routine is called before a subsequent
333 * call to region_add that will actually modify the reserve
334 * map to add the specified range [f, t). region_chg does
335 * not change the number of huge pages represented by the
336 * map. However, if the existing regions in the map can not
337 * be expanded to represent the new range, a new file_region
338 * structure is added to the map as a placeholder. This is
339 * so that the subsequent region_add call will have all the
340 * regions it needs and will not fail.
342 * Upon entry, region_chg will also examine the cache of region descriptors
343 * associated with the map. If there are not enough descriptors cached, one
344 * will be allocated for the in progress add operation.
346 * Returns the number of huge pages that need to be added to the existing
347 * reservation map for the range [f, t). This number is greater or equal to
348 * zero. -ENOMEM is returned if a new file_region structure or cache entry
349 * is needed and can not be allocated.
351 static long region_chg(struct resv_map
*resv
, long f
, long t
)
353 struct list_head
*head
= &resv
->regions
;
354 struct file_region
*rg
, *nrg
= NULL
;
358 spin_lock(&resv
->lock
);
360 resv
->adds_in_progress
++;
363 * Check for sufficient descriptors in the cache to accommodate
364 * the number of in progress add operations.
366 if (resv
->adds_in_progress
> resv
->region_cache_count
) {
367 struct file_region
*trg
;
369 VM_BUG_ON(resv
->adds_in_progress
- resv
->region_cache_count
> 1);
370 /* Must drop lock to allocate a new descriptor. */
371 resv
->adds_in_progress
--;
372 spin_unlock(&resv
->lock
);
374 trg
= kmalloc(sizeof(*trg
), GFP_KERNEL
);
378 spin_lock(&resv
->lock
);
379 list_add(&trg
->link
, &resv
->region_cache
);
380 resv
->region_cache_count
++;
384 /* Locate the region we are before or in. */
385 list_for_each_entry(rg
, head
, link
)
389 /* If we are below the current region then a new region is required.
390 * Subtle, allocate a new region at the position but make it zero
391 * size such that we can guarantee to record the reservation. */
392 if (&rg
->link
== head
|| t
< rg
->from
) {
394 resv
->adds_in_progress
--;
395 spin_unlock(&resv
->lock
);
396 nrg
= kmalloc(sizeof(*nrg
), GFP_KERNEL
);
402 INIT_LIST_HEAD(&nrg
->link
);
406 list_add(&nrg
->link
, rg
->link
.prev
);
411 /* Round our left edge to the current segment if it encloses us. */
416 /* Check for and consume any regions we now overlap with. */
417 list_for_each_entry(rg
, rg
->link
.prev
, link
) {
418 if (&rg
->link
== head
)
423 /* We overlap with this area, if it extends further than
424 * us then we must extend ourselves. Account for its
425 * existing reservation. */
430 chg
-= rg
->to
- rg
->from
;
434 spin_unlock(&resv
->lock
);
435 /* We already know we raced and no longer need the new region */
439 spin_unlock(&resv
->lock
);
444 * Abort the in progress add operation. The adds_in_progress field
445 * of the resv_map keeps track of the operations in progress between
446 * calls to region_chg and region_add. Operations are sometimes
447 * aborted after the call to region_chg. In such cases, region_abort
448 * is called to decrement the adds_in_progress counter.
450 * NOTE: The range arguments [f, t) are not needed or used in this
451 * routine. They are kept to make reading the calling code easier as
452 * arguments will match the associated region_chg call.
454 static void region_abort(struct resv_map
*resv
, long f
, long t
)
456 spin_lock(&resv
->lock
);
457 VM_BUG_ON(!resv
->region_cache_count
);
458 resv
->adds_in_progress
--;
459 spin_unlock(&resv
->lock
);
463 * Truncate the reserve map at index 'end'. Modify/truncate any
464 * region which contains end. Delete any regions past end.
465 * Return the number of huge pages removed from the map.
467 static long region_truncate(struct resv_map
*resv
, long end
)
469 struct list_head
*head
= &resv
->regions
;
470 struct file_region
*rg
, *trg
;
473 spin_lock(&resv
->lock
);
474 /* Locate the region we are either in or before. */
475 list_for_each_entry(rg
, head
, link
)
478 if (&rg
->link
== head
)
481 /* If we are in the middle of a region then adjust it. */
482 if (end
> rg
->from
) {
485 rg
= list_entry(rg
->link
.next
, typeof(*rg
), link
);
488 /* Drop any remaining regions. */
489 list_for_each_entry_safe(rg
, trg
, rg
->link
.prev
, link
) {
490 if (&rg
->link
== head
)
492 chg
+= rg
->to
- rg
->from
;
498 spin_unlock(&resv
->lock
);
503 * Count and return the number of huge pages in the reserve map
504 * that intersect with the range [f, t).
506 static long region_count(struct resv_map
*resv
, long f
, long t
)
508 struct list_head
*head
= &resv
->regions
;
509 struct file_region
*rg
;
512 spin_lock(&resv
->lock
);
513 /* Locate each segment we overlap with, and count that overlap. */
514 list_for_each_entry(rg
, head
, link
) {
523 seg_from
= max(rg
->from
, f
);
524 seg_to
= min(rg
->to
, t
);
526 chg
+= seg_to
- seg_from
;
528 spin_unlock(&resv
->lock
);
534 * Convert the address within this vma to the page offset within
535 * the mapping, in pagecache page units; huge pages here.
537 static pgoff_t
vma_hugecache_offset(struct hstate
*h
,
538 struct vm_area_struct
*vma
, unsigned long address
)
540 return ((address
- vma
->vm_start
) >> huge_page_shift(h
)) +
541 (vma
->vm_pgoff
>> huge_page_order(h
));
544 pgoff_t
linear_hugepage_index(struct vm_area_struct
*vma
,
545 unsigned long address
)
547 return vma_hugecache_offset(hstate_vma(vma
), vma
, address
);
551 * Return the size of the pages allocated when backing a VMA. In the majority
552 * cases this will be same size as used by the page table entries.
554 unsigned long vma_kernel_pagesize(struct vm_area_struct
*vma
)
556 struct hstate
*hstate
;
558 if (!is_vm_hugetlb_page(vma
))
561 hstate
= hstate_vma(vma
);
563 return 1UL << huge_page_shift(hstate
);
565 EXPORT_SYMBOL_GPL(vma_kernel_pagesize
);
568 * Return the page size being used by the MMU to back a VMA. In the majority
569 * of cases, the page size used by the kernel matches the MMU size. On
570 * architectures where it differs, an architecture-specific version of this
571 * function is required.
573 #ifndef vma_mmu_pagesize
574 unsigned long vma_mmu_pagesize(struct vm_area_struct
*vma
)
576 return vma_kernel_pagesize(vma
);
581 * Flags for MAP_PRIVATE reservations. These are stored in the bottom
582 * bits of the reservation map pointer, which are always clear due to
585 #define HPAGE_RESV_OWNER (1UL << 0)
586 #define HPAGE_RESV_UNMAPPED (1UL << 1)
587 #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED)
590 * These helpers are used to track how many pages are reserved for
591 * faults in a MAP_PRIVATE mapping. Only the process that called mmap()
592 * is guaranteed to have their future faults succeed.
594 * With the exception of reset_vma_resv_huge_pages() which is called at fork(),
595 * the reserve counters are updated with the hugetlb_lock held. It is safe
596 * to reset the VMA at fork() time as it is not in use yet and there is no
597 * chance of the global counters getting corrupted as a result of the values.
599 * The private mapping reservation is represented in a subtly different
600 * manner to a shared mapping. A shared mapping has a region map associated
601 * with the underlying file, this region map represents the backing file
602 * pages which have ever had a reservation assigned which this persists even
603 * after the page is instantiated. A private mapping has a region map
604 * associated with the original mmap which is attached to all VMAs which
605 * reference it, this region map represents those offsets which have consumed
606 * reservation ie. where pages have been instantiated.
608 static unsigned long get_vma_private_data(struct vm_area_struct
*vma
)
610 return (unsigned long)vma
->vm_private_data
;
613 static void set_vma_private_data(struct vm_area_struct
*vma
,
616 vma
->vm_private_data
= (void *)value
;
619 struct resv_map
*resv_map_alloc(void)
621 struct resv_map
*resv_map
= kmalloc(sizeof(*resv_map
), GFP_KERNEL
);
622 struct file_region
*rg
= kmalloc(sizeof(*rg
), GFP_KERNEL
);
624 if (!resv_map
|| !rg
) {
630 kref_init(&resv_map
->refs
);
631 spin_lock_init(&resv_map
->lock
);
632 INIT_LIST_HEAD(&resv_map
->regions
);
634 resv_map
->adds_in_progress
= 0;
636 INIT_LIST_HEAD(&resv_map
->region_cache
);
637 list_add(&rg
->link
, &resv_map
->region_cache
);
638 resv_map
->region_cache_count
= 1;
643 void resv_map_release(struct kref
*ref
)
645 struct resv_map
*resv_map
= container_of(ref
, struct resv_map
, refs
);
646 struct list_head
*head
= &resv_map
->region_cache
;
647 struct file_region
*rg
, *trg
;
649 /* Clear out any active regions before we release the map. */
650 region_truncate(resv_map
, 0);
652 /* ... and any entries left in the cache */
653 list_for_each_entry_safe(rg
, trg
, head
, link
) {
658 VM_BUG_ON(resv_map
->adds_in_progress
);
663 static inline struct resv_map
*inode_resv_map(struct inode
*inode
)
665 return inode
->i_mapping
->private_data
;
668 static struct resv_map
*vma_resv_map(struct vm_area_struct
*vma
)
670 VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma
), vma
);
671 if (vma
->vm_flags
& VM_MAYSHARE
) {
672 struct address_space
*mapping
= vma
->vm_file
->f_mapping
;
673 struct inode
*inode
= mapping
->host
;
675 return inode_resv_map(inode
);
678 return (struct resv_map
*)(get_vma_private_data(vma
) &
683 static void set_vma_resv_map(struct vm_area_struct
*vma
, struct resv_map
*map
)
685 VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma
), vma
);
686 VM_BUG_ON_VMA(vma
->vm_flags
& VM_MAYSHARE
, vma
);
688 set_vma_private_data(vma
, (get_vma_private_data(vma
) &
689 HPAGE_RESV_MASK
) | (unsigned long)map
);
692 static void set_vma_resv_flags(struct vm_area_struct
*vma
, unsigned long flags
)
694 VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma
), vma
);
695 VM_BUG_ON_VMA(vma
->vm_flags
& VM_MAYSHARE
, vma
);
697 set_vma_private_data(vma
, get_vma_private_data(vma
) | flags
);
700 static int is_vma_resv_set(struct vm_area_struct
*vma
, unsigned long flag
)
702 VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma
), vma
);
704 return (get_vma_private_data(vma
) & flag
) != 0;
707 /* Reset counters to 0 and clear all HPAGE_RESV_* flags */
708 void reset_vma_resv_huge_pages(struct vm_area_struct
*vma
)
710 VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma
), vma
);
711 if (!(vma
->vm_flags
& VM_MAYSHARE
))
712 vma
->vm_private_data
= (void *)0;
715 /* Returns true if the VMA has associated reserve pages */
716 static bool vma_has_reserves(struct vm_area_struct
*vma
, long chg
)
718 if (vma
->vm_flags
& VM_NORESERVE
) {
720 * This address is already reserved by other process(chg == 0),
721 * so, we should decrement reserved count. Without decrementing,
722 * reserve count remains after releasing inode, because this
723 * allocated page will go into page cache and is regarded as
724 * coming from reserved pool in releasing step. Currently, we
725 * don't have any other solution to deal with this situation
726 * properly, so add work-around here.
728 if (vma
->vm_flags
& VM_MAYSHARE
&& chg
== 0)
734 /* Shared mappings always use reserves */
735 if (vma
->vm_flags
& VM_MAYSHARE
)
739 * Only the process that called mmap() has reserves for
742 if (is_vma_resv_set(vma
, HPAGE_RESV_OWNER
))
748 static void enqueue_huge_page(struct hstate
*h
, struct page
*page
)
750 int nid
= page_to_nid(page
);
751 list_move(&page
->lru
, &h
->hugepage_freelists
[nid
]);
752 h
->free_huge_pages
++;
753 h
->free_huge_pages_node
[nid
]++;
756 static struct page
*dequeue_huge_page_node(struct hstate
*h
, int nid
)
760 list_for_each_entry(page
, &h
->hugepage_freelists
[nid
], lru
)
761 if (!is_migrate_isolate_page(page
))
764 * if 'non-isolated free hugepage' not found on the list,
765 * the allocation fails.
767 if (&h
->hugepage_freelists
[nid
] == &page
->lru
)
769 list_move(&page
->lru
, &h
->hugepage_activelist
);
770 set_page_refcounted(page
);
771 h
->free_huge_pages
--;
772 h
->free_huge_pages_node
[nid
]--;
776 /* Movability of hugepages depends on migration support. */
777 static inline gfp_t
htlb_alloc_mask(struct hstate
*h
)
779 if (hugepages_treat_as_movable
|| hugepage_migration_supported(h
))
780 return GFP_HIGHUSER_MOVABLE
;
785 static struct page
*dequeue_huge_page_vma(struct hstate
*h
,
786 struct vm_area_struct
*vma
,
787 unsigned long address
, int avoid_reserve
,
790 struct page
*page
= NULL
;
791 struct mempolicy
*mpol
;
792 nodemask_t
*nodemask
;
793 struct zonelist
*zonelist
;
796 unsigned int cpuset_mems_cookie
;
799 * A child process with MAP_PRIVATE mappings created by their parent
800 * have no page reserves. This check ensures that reservations are
801 * not "stolen". The child may still get SIGKILLed
803 if (!vma_has_reserves(vma
, chg
) &&
804 h
->free_huge_pages
- h
->resv_huge_pages
== 0)
807 /* If reserves cannot be used, ensure enough pages are in the pool */
808 if (avoid_reserve
&& h
->free_huge_pages
- h
->resv_huge_pages
== 0)
812 cpuset_mems_cookie
= read_mems_allowed_begin();
813 zonelist
= huge_zonelist(vma
, address
,
814 htlb_alloc_mask(h
), &mpol
, &nodemask
);
816 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
817 MAX_NR_ZONES
- 1, nodemask
) {
818 if (cpuset_zone_allowed(zone
, htlb_alloc_mask(h
))) {
819 page
= dequeue_huge_page_node(h
, zone_to_nid(zone
));
823 if (!vma_has_reserves(vma
, chg
))
826 SetPagePrivate(page
);
827 h
->resv_huge_pages
--;
834 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
843 * common helper functions for hstate_next_node_to_{alloc|free}.
844 * We may have allocated or freed a huge page based on a different
845 * nodes_allowed previously, so h->next_node_to_{alloc|free} might
846 * be outside of *nodes_allowed. Ensure that we use an allowed
847 * node for alloc or free.
849 static int next_node_allowed(int nid
, nodemask_t
*nodes_allowed
)
851 nid
= next_node(nid
, *nodes_allowed
);
852 if (nid
== MAX_NUMNODES
)
853 nid
= first_node(*nodes_allowed
);
854 VM_BUG_ON(nid
>= MAX_NUMNODES
);
859 static int get_valid_node_allowed(int nid
, nodemask_t
*nodes_allowed
)
861 if (!node_isset(nid
, *nodes_allowed
))
862 nid
= next_node_allowed(nid
, nodes_allowed
);
867 * returns the previously saved node ["this node"] from which to
868 * allocate a persistent huge page for the pool and advance the
869 * next node from which to allocate, handling wrap at end of node
872 static int hstate_next_node_to_alloc(struct hstate
*h
,
873 nodemask_t
*nodes_allowed
)
877 VM_BUG_ON(!nodes_allowed
);
879 nid
= get_valid_node_allowed(h
->next_nid_to_alloc
, nodes_allowed
);
880 h
->next_nid_to_alloc
= next_node_allowed(nid
, nodes_allowed
);
886 * helper for free_pool_huge_page() - return the previously saved
887 * node ["this node"] from which to free a huge page. Advance the
888 * next node id whether or not we find a free huge page to free so
889 * that the next attempt to free addresses the next node.
891 static int hstate_next_node_to_free(struct hstate
*h
, nodemask_t
*nodes_allowed
)
895 VM_BUG_ON(!nodes_allowed
);
897 nid
= get_valid_node_allowed(h
->next_nid_to_free
, nodes_allowed
);
898 h
->next_nid_to_free
= next_node_allowed(nid
, nodes_allowed
);
903 #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \
904 for (nr_nodes = nodes_weight(*mask); \
906 ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \
909 #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \
910 for (nr_nodes = nodes_weight(*mask); \
912 ((node = hstate_next_node_to_free(hs, mask)) || 1); \
915 #if defined(CONFIG_CMA) && defined(CONFIG_X86_64)
916 static void destroy_compound_gigantic_page(struct page
*page
,
920 int nr_pages
= 1 << order
;
921 struct page
*p
= page
+ 1;
923 for (i
= 1; i
< nr_pages
; i
++, p
= mem_map_next(p
, page
, i
)) {
925 set_page_refcounted(p
);
926 p
->first_page
= NULL
;
929 set_compound_order(page
, 0);
930 __ClearPageHead(page
);
933 static void free_gigantic_page(struct page
*page
, unsigned order
)
935 free_contig_range(page_to_pfn(page
), 1 << order
);
938 static int __alloc_gigantic_page(unsigned long start_pfn
,
939 unsigned long nr_pages
)
941 unsigned long end_pfn
= start_pfn
+ nr_pages
;
942 return alloc_contig_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
);
945 static bool pfn_range_valid_gigantic(unsigned long start_pfn
,
946 unsigned long nr_pages
)
948 unsigned long i
, end_pfn
= start_pfn
+ nr_pages
;
951 for (i
= start_pfn
; i
< end_pfn
; i
++) {
955 page
= pfn_to_page(i
);
957 if (PageReserved(page
))
960 if (page_count(page
) > 0)
970 static bool zone_spans_last_pfn(const struct zone
*zone
,
971 unsigned long start_pfn
, unsigned long nr_pages
)
973 unsigned long last_pfn
= start_pfn
+ nr_pages
- 1;
974 return zone_spans_pfn(zone
, last_pfn
);
977 static struct page
*alloc_gigantic_page(int nid
, unsigned order
)
979 unsigned long nr_pages
= 1 << order
;
980 unsigned long ret
, pfn
, flags
;
983 z
= NODE_DATA(nid
)->node_zones
;
984 for (; z
- NODE_DATA(nid
)->node_zones
< MAX_NR_ZONES
; z
++) {
985 spin_lock_irqsave(&z
->lock
, flags
);
987 pfn
= ALIGN(z
->zone_start_pfn
, nr_pages
);
988 while (zone_spans_last_pfn(z
, pfn
, nr_pages
)) {
989 if (pfn_range_valid_gigantic(pfn
, nr_pages
)) {
991 * We release the zone lock here because
992 * alloc_contig_range() will also lock the zone
993 * at some point. If there's an allocation
994 * spinning on this lock, it may win the race
995 * and cause alloc_contig_range() to fail...
997 spin_unlock_irqrestore(&z
->lock
, flags
);
998 ret
= __alloc_gigantic_page(pfn
, nr_pages
);
1000 return pfn_to_page(pfn
);
1001 spin_lock_irqsave(&z
->lock
, flags
);
1006 spin_unlock_irqrestore(&z
->lock
, flags
);
1012 static void prep_new_huge_page(struct hstate
*h
, struct page
*page
, int nid
);
1013 static void prep_compound_gigantic_page(struct page
*page
, unsigned long order
);
1015 static struct page
*alloc_fresh_gigantic_page_node(struct hstate
*h
, int nid
)
1019 page
= alloc_gigantic_page(nid
, huge_page_order(h
));
1021 prep_compound_gigantic_page(page
, huge_page_order(h
));
1022 prep_new_huge_page(h
, page
, nid
);
1028 static int alloc_fresh_gigantic_page(struct hstate
*h
,
1029 nodemask_t
*nodes_allowed
)
1031 struct page
*page
= NULL
;
1034 for_each_node_mask_to_alloc(h
, nr_nodes
, node
, nodes_allowed
) {
1035 page
= alloc_fresh_gigantic_page_node(h
, node
);
1043 static inline bool gigantic_page_supported(void) { return true; }
1045 static inline bool gigantic_page_supported(void) { return false; }
1046 static inline void free_gigantic_page(struct page
*page
, unsigned order
) { }
1047 static inline void destroy_compound_gigantic_page(struct page
*page
,
1048 unsigned long order
) { }
1049 static inline int alloc_fresh_gigantic_page(struct hstate
*h
,
1050 nodemask_t
*nodes_allowed
) { return 0; }
1053 static void update_and_free_page(struct hstate
*h
, struct page
*page
)
1057 if (hstate_is_gigantic(h
) && !gigantic_page_supported())
1061 h
->nr_huge_pages_node
[page_to_nid(page
)]--;
1062 for (i
= 0; i
< pages_per_huge_page(h
); i
++) {
1063 page
[i
].flags
&= ~(1 << PG_locked
| 1 << PG_error
|
1064 1 << PG_referenced
| 1 << PG_dirty
|
1065 1 << PG_active
| 1 << PG_private
|
1068 VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page
), page
);
1069 set_compound_page_dtor(page
, NULL
);
1070 set_page_refcounted(page
);
1071 if (hstate_is_gigantic(h
)) {
1072 destroy_compound_gigantic_page(page
, huge_page_order(h
));
1073 free_gigantic_page(page
, huge_page_order(h
));
1075 __free_pages(page
, huge_page_order(h
));
1079 struct hstate
*size_to_hstate(unsigned long size
)
1083 for_each_hstate(h
) {
1084 if (huge_page_size(h
) == size
)
1091 * Test to determine whether the hugepage is "active/in-use" (i.e. being linked
1092 * to hstate->hugepage_activelist.)
1094 * This function can be called for tail pages, but never returns true for them.
1096 bool page_huge_active(struct page
*page
)
1098 VM_BUG_ON_PAGE(!PageHuge(page
), page
);
1099 return PageHead(page
) && PagePrivate(&page
[1]);
1102 /* never called for tail page */
1103 static void set_page_huge_active(struct page
*page
)
1105 VM_BUG_ON_PAGE(!PageHeadHuge(page
), page
);
1106 SetPagePrivate(&page
[1]);
1109 static void clear_page_huge_active(struct page
*page
)
1111 VM_BUG_ON_PAGE(!PageHeadHuge(page
), page
);
1112 ClearPagePrivate(&page
[1]);
1115 void free_huge_page(struct page
*page
)
1118 * Can't pass hstate in here because it is called from the
1119 * compound page destructor.
1121 struct hstate
*h
= page_hstate(page
);
1122 int nid
= page_to_nid(page
);
1123 struct hugepage_subpool
*spool
=
1124 (struct hugepage_subpool
*)page_private(page
);
1125 bool restore_reserve
;
1127 set_page_private(page
, 0);
1128 page
->mapping
= NULL
;
1129 BUG_ON(page_count(page
));
1130 BUG_ON(page_mapcount(page
));
1131 restore_reserve
= PagePrivate(page
);
1132 ClearPagePrivate(page
);
1135 * A return code of zero implies that the subpool will be under its
1136 * minimum size if the reservation is not restored after page is free.
1137 * Therefore, force restore_reserve operation.
1139 if (hugepage_subpool_put_pages(spool
, 1) == 0)
1140 restore_reserve
= true;
1142 spin_lock(&hugetlb_lock
);
1143 clear_page_huge_active(page
);
1144 hugetlb_cgroup_uncharge_page(hstate_index(h
),
1145 pages_per_huge_page(h
), page
);
1146 if (restore_reserve
)
1147 h
->resv_huge_pages
++;
1149 if (h
->surplus_huge_pages_node
[nid
]) {
1150 /* remove the page from active list */
1151 list_del(&page
->lru
);
1152 update_and_free_page(h
, page
);
1153 h
->surplus_huge_pages
--;
1154 h
->surplus_huge_pages_node
[nid
]--;
1156 arch_clear_hugepage_flags(page
);
1157 enqueue_huge_page(h
, page
);
1159 spin_unlock(&hugetlb_lock
);
1162 static void prep_new_huge_page(struct hstate
*h
, struct page
*page
, int nid
)
1164 INIT_LIST_HEAD(&page
->lru
);
1165 set_compound_page_dtor(page
, free_huge_page
);
1166 spin_lock(&hugetlb_lock
);
1167 set_hugetlb_cgroup(page
, NULL
);
1169 h
->nr_huge_pages_node
[nid
]++;
1170 spin_unlock(&hugetlb_lock
);
1171 put_page(page
); /* free it into the hugepage allocator */
1174 static void prep_compound_gigantic_page(struct page
*page
, unsigned long order
)
1177 int nr_pages
= 1 << order
;
1178 struct page
*p
= page
+ 1;
1180 /* we rely on prep_new_huge_page to set the destructor */
1181 set_compound_order(page
, order
);
1182 __SetPageHead(page
);
1183 __ClearPageReserved(page
);
1184 for (i
= 1; i
< nr_pages
; i
++, p
= mem_map_next(p
, page
, i
)) {
1186 * For gigantic hugepages allocated through bootmem at
1187 * boot, it's safer to be consistent with the not-gigantic
1188 * hugepages and clear the PG_reserved bit from all tail pages
1189 * too. Otherwse drivers using get_user_pages() to access tail
1190 * pages may get the reference counting wrong if they see
1191 * PG_reserved set on a tail page (despite the head page not
1192 * having PG_reserved set). Enforcing this consistency between
1193 * head and tail pages allows drivers to optimize away a check
1194 * on the head page when they need know if put_page() is needed
1195 * after get_user_pages().
1197 __ClearPageReserved(p
);
1198 set_page_count(p
, 0);
1199 p
->first_page
= page
;
1200 /* Make sure p->first_page is always valid for PageTail() */
1207 * PageHuge() only returns true for hugetlbfs pages, but not for normal or
1208 * transparent huge pages. See the PageTransHuge() documentation for more
1211 int PageHuge(struct page
*page
)
1213 if (!PageCompound(page
))
1216 page
= compound_head(page
);
1217 return get_compound_page_dtor(page
) == free_huge_page
;
1219 EXPORT_SYMBOL_GPL(PageHuge
);
1222 * PageHeadHuge() only returns true for hugetlbfs head page, but not for
1223 * normal or transparent huge pages.
1225 int PageHeadHuge(struct page
*page_head
)
1227 if (!PageHead(page_head
))
1230 return get_compound_page_dtor(page_head
) == free_huge_page
;
1233 pgoff_t
__basepage_index(struct page
*page
)
1235 struct page
*page_head
= compound_head(page
);
1236 pgoff_t index
= page_index(page_head
);
1237 unsigned long compound_idx
;
1239 if (!PageHuge(page_head
))
1240 return page_index(page
);
1242 if (compound_order(page_head
) >= MAX_ORDER
)
1243 compound_idx
= page_to_pfn(page
) - page_to_pfn(page_head
);
1245 compound_idx
= page
- page_head
;
1247 return (index
<< compound_order(page_head
)) + compound_idx
;
1250 static struct page
*alloc_fresh_huge_page_node(struct hstate
*h
, int nid
)
1254 page
= alloc_pages_exact_node(nid
,
1255 htlb_alloc_mask(h
)|__GFP_COMP
|__GFP_THISNODE
|
1256 __GFP_REPEAT
|__GFP_NOWARN
,
1257 huge_page_order(h
));
1259 prep_new_huge_page(h
, page
, nid
);
1265 static int alloc_fresh_huge_page(struct hstate
*h
, nodemask_t
*nodes_allowed
)
1271 for_each_node_mask_to_alloc(h
, nr_nodes
, node
, nodes_allowed
) {
1272 page
= alloc_fresh_huge_page_node(h
, node
);
1280 count_vm_event(HTLB_BUDDY_PGALLOC
);
1282 count_vm_event(HTLB_BUDDY_PGALLOC_FAIL
);
1288 * Free huge page from pool from next node to free.
1289 * Attempt to keep persistent huge pages more or less
1290 * balanced over allowed nodes.
1291 * Called with hugetlb_lock locked.
1293 static int free_pool_huge_page(struct hstate
*h
, nodemask_t
*nodes_allowed
,
1299 for_each_node_mask_to_free(h
, nr_nodes
, node
, nodes_allowed
) {
1301 * If we're returning unused surplus pages, only examine
1302 * nodes with surplus pages.
1304 if ((!acct_surplus
|| h
->surplus_huge_pages_node
[node
]) &&
1305 !list_empty(&h
->hugepage_freelists
[node
])) {
1307 list_entry(h
->hugepage_freelists
[node
].next
,
1309 list_del(&page
->lru
);
1310 h
->free_huge_pages
--;
1311 h
->free_huge_pages_node
[node
]--;
1313 h
->surplus_huge_pages
--;
1314 h
->surplus_huge_pages_node
[node
]--;
1316 update_and_free_page(h
, page
);
1326 * Dissolve a given free hugepage into free buddy pages. This function does
1327 * nothing for in-use (including surplus) hugepages.
1329 static void dissolve_free_huge_page(struct page
*page
)
1331 spin_lock(&hugetlb_lock
);
1332 if (PageHuge(page
) && !page_count(page
)) {
1333 struct hstate
*h
= page_hstate(page
);
1334 int nid
= page_to_nid(page
);
1335 list_del(&page
->lru
);
1336 h
->free_huge_pages
--;
1337 h
->free_huge_pages_node
[nid
]--;
1338 update_and_free_page(h
, page
);
1340 spin_unlock(&hugetlb_lock
);
1344 * Dissolve free hugepages in a given pfn range. Used by memory hotplug to
1345 * make specified memory blocks removable from the system.
1346 * Note that start_pfn should aligned with (minimum) hugepage size.
1348 void dissolve_free_huge_pages(unsigned long start_pfn
, unsigned long end_pfn
)
1352 if (!hugepages_supported())
1355 VM_BUG_ON(!IS_ALIGNED(start_pfn
, 1 << minimum_order
));
1356 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= 1 << minimum_order
)
1357 dissolve_free_huge_page(pfn_to_page(pfn
));
1360 static struct page
*alloc_buddy_huge_page(struct hstate
*h
, int nid
)
1365 if (hstate_is_gigantic(h
))
1369 * Assume we will successfully allocate the surplus page to
1370 * prevent racing processes from causing the surplus to exceed
1373 * This however introduces a different race, where a process B
1374 * tries to grow the static hugepage pool while alloc_pages() is
1375 * called by process A. B will only examine the per-node
1376 * counters in determining if surplus huge pages can be
1377 * converted to normal huge pages in adjust_pool_surplus(). A
1378 * won't be able to increment the per-node counter, until the
1379 * lock is dropped by B, but B doesn't drop hugetlb_lock until
1380 * no more huge pages can be converted from surplus to normal
1381 * state (and doesn't try to convert again). Thus, we have a
1382 * case where a surplus huge page exists, the pool is grown, and
1383 * the surplus huge page still exists after, even though it
1384 * should just have been converted to a normal huge page. This
1385 * does not leak memory, though, as the hugepage will be freed
1386 * once it is out of use. It also does not allow the counters to
1387 * go out of whack in adjust_pool_surplus() as we don't modify
1388 * the node values until we've gotten the hugepage and only the
1389 * per-node value is checked there.
1391 spin_lock(&hugetlb_lock
);
1392 if (h
->surplus_huge_pages
>= h
->nr_overcommit_huge_pages
) {
1393 spin_unlock(&hugetlb_lock
);
1397 h
->surplus_huge_pages
++;
1399 spin_unlock(&hugetlb_lock
);
1401 if (nid
== NUMA_NO_NODE
)
1402 page
= alloc_pages(htlb_alloc_mask(h
)|__GFP_COMP
|
1403 __GFP_REPEAT
|__GFP_NOWARN
,
1404 huge_page_order(h
));
1406 page
= alloc_pages_exact_node(nid
,
1407 htlb_alloc_mask(h
)|__GFP_COMP
|__GFP_THISNODE
|
1408 __GFP_REPEAT
|__GFP_NOWARN
, huge_page_order(h
));
1410 spin_lock(&hugetlb_lock
);
1412 INIT_LIST_HEAD(&page
->lru
);
1413 r_nid
= page_to_nid(page
);
1414 set_compound_page_dtor(page
, free_huge_page
);
1415 set_hugetlb_cgroup(page
, NULL
);
1417 * We incremented the global counters already
1419 h
->nr_huge_pages_node
[r_nid
]++;
1420 h
->surplus_huge_pages_node
[r_nid
]++;
1421 __count_vm_event(HTLB_BUDDY_PGALLOC
);
1424 h
->surplus_huge_pages
--;
1425 __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL
);
1427 spin_unlock(&hugetlb_lock
);
1433 * This allocation function is useful in the context where vma is irrelevant.
1434 * E.g. soft-offlining uses this function because it only cares physical
1435 * address of error page.
1437 struct page
*alloc_huge_page_node(struct hstate
*h
, int nid
)
1439 struct page
*page
= NULL
;
1441 spin_lock(&hugetlb_lock
);
1442 if (h
->free_huge_pages
- h
->resv_huge_pages
> 0)
1443 page
= dequeue_huge_page_node(h
, nid
);
1444 spin_unlock(&hugetlb_lock
);
1447 page
= alloc_buddy_huge_page(h
, nid
);
1453 * Increase the hugetlb pool such that it can accommodate a reservation
1456 static int gather_surplus_pages(struct hstate
*h
, int delta
)
1458 struct list_head surplus_list
;
1459 struct page
*page
, *tmp
;
1461 int needed
, allocated
;
1462 bool alloc_ok
= true;
1464 needed
= (h
->resv_huge_pages
+ delta
) - h
->free_huge_pages
;
1466 h
->resv_huge_pages
+= delta
;
1471 INIT_LIST_HEAD(&surplus_list
);
1475 spin_unlock(&hugetlb_lock
);
1476 for (i
= 0; i
< needed
; i
++) {
1477 page
= alloc_buddy_huge_page(h
, NUMA_NO_NODE
);
1482 list_add(&page
->lru
, &surplus_list
);
1487 * After retaking hugetlb_lock, we need to recalculate 'needed'
1488 * because either resv_huge_pages or free_huge_pages may have changed.
1490 spin_lock(&hugetlb_lock
);
1491 needed
= (h
->resv_huge_pages
+ delta
) -
1492 (h
->free_huge_pages
+ allocated
);
1497 * We were not able to allocate enough pages to
1498 * satisfy the entire reservation so we free what
1499 * we've allocated so far.
1504 * The surplus_list now contains _at_least_ the number of extra pages
1505 * needed to accommodate the reservation. Add the appropriate number
1506 * of pages to the hugetlb pool and free the extras back to the buddy
1507 * allocator. Commit the entire reservation here to prevent another
1508 * process from stealing the pages as they are added to the pool but
1509 * before they are reserved.
1511 needed
+= allocated
;
1512 h
->resv_huge_pages
+= delta
;
1515 /* Free the needed pages to the hugetlb pool */
1516 list_for_each_entry_safe(page
, tmp
, &surplus_list
, lru
) {
1520 * This page is now managed by the hugetlb allocator and has
1521 * no users -- drop the buddy allocator's reference.
1523 put_page_testzero(page
);
1524 VM_BUG_ON_PAGE(page_count(page
), page
);
1525 enqueue_huge_page(h
, page
);
1528 spin_unlock(&hugetlb_lock
);
1530 /* Free unnecessary surplus pages to the buddy allocator */
1531 list_for_each_entry_safe(page
, tmp
, &surplus_list
, lru
)
1533 spin_lock(&hugetlb_lock
);
1539 * When releasing a hugetlb pool reservation, any surplus pages that were
1540 * allocated to satisfy the reservation must be explicitly freed if they were
1542 * Called with hugetlb_lock held.
1544 static void return_unused_surplus_pages(struct hstate
*h
,
1545 unsigned long unused_resv_pages
)
1547 unsigned long nr_pages
;
1549 /* Uncommit the reservation */
1550 h
->resv_huge_pages
-= unused_resv_pages
;
1552 /* Cannot return gigantic pages currently */
1553 if (hstate_is_gigantic(h
))
1556 nr_pages
= min(unused_resv_pages
, h
->surplus_huge_pages
);
1559 * We want to release as many surplus pages as possible, spread
1560 * evenly across all nodes with memory. Iterate across these nodes
1561 * until we can no longer free unreserved surplus pages. This occurs
1562 * when the nodes with surplus pages have no free pages.
1563 * free_pool_huge_page() will balance the the freed pages across the
1564 * on-line nodes with memory and will handle the hstate accounting.
1566 while (nr_pages
--) {
1567 if (!free_pool_huge_page(h
, &node_states
[N_MEMORY
], 1))
1569 cond_resched_lock(&hugetlb_lock
);
1575 * vma_needs_reservation, vma_commit_reservation and vma_abort_reservation
1576 * are used by the huge page allocation routines to manage reservations.
1578 * vma_needs_reservation is called to determine if the huge page at addr
1579 * within the vma has an associated reservation. If a reservation is
1580 * needed, the value 1 is returned. The caller is then responsible for
1581 * managing the global reservation and subpool usage counts. After
1582 * the huge page has been allocated, vma_commit_reservation is called
1583 * to add the page to the reservation map. If the reservation must be
1584 * aborted instead of committed, vma_abort_reservation is called.
1586 * In the normal case, vma_commit_reservation returns the same value
1587 * as the preceding vma_needs_reservation call. The only time this
1588 * is not the case is if a reserve map was changed between calls. It
1589 * is the responsibility of the caller to notice the difference and
1590 * take appropriate action.
1592 enum vma_resv_mode
{
1597 static long __vma_reservation_common(struct hstate
*h
,
1598 struct vm_area_struct
*vma
, unsigned long addr
,
1599 enum vma_resv_mode mode
)
1601 struct resv_map
*resv
;
1605 resv
= vma_resv_map(vma
);
1609 idx
= vma_hugecache_offset(h
, vma
, addr
);
1611 case VMA_NEEDS_RESV
:
1612 ret
= region_chg(resv
, idx
, idx
+ 1);
1614 case VMA_COMMIT_RESV
:
1615 ret
= region_add(resv
, idx
, idx
+ 1);
1617 case VMA_ABORT_RESV
:
1618 region_abort(resv
, idx
, idx
+ 1);
1625 if (vma
->vm_flags
& VM_MAYSHARE
)
1628 return ret
< 0 ? ret
: 0;
1631 static long vma_needs_reservation(struct hstate
*h
,
1632 struct vm_area_struct
*vma
, unsigned long addr
)
1634 return __vma_reservation_common(h
, vma
, addr
, VMA_NEEDS_RESV
);
1637 static long vma_commit_reservation(struct hstate
*h
,
1638 struct vm_area_struct
*vma
, unsigned long addr
)
1640 return __vma_reservation_common(h
, vma
, addr
, VMA_COMMIT_RESV
);
1643 static void vma_abort_reservation(struct hstate
*h
,
1644 struct vm_area_struct
*vma
, unsigned long addr
)
1646 (void)__vma_reservation_common(h
, vma
, addr
, VMA_ABORT_RESV
);
1649 static struct page
*alloc_huge_page(struct vm_area_struct
*vma
,
1650 unsigned long addr
, int avoid_reserve
)
1652 struct hugepage_subpool
*spool
= subpool_vma(vma
);
1653 struct hstate
*h
= hstate_vma(vma
);
1657 struct hugetlb_cgroup
*h_cg
;
1659 idx
= hstate_index(h
);
1661 * Processes that did not create the mapping will have no
1662 * reserves and will not have accounted against subpool
1663 * limit. Check that the subpool limit can be made before
1664 * satisfying the allocation MAP_NORESERVE mappings may also
1665 * need pages and subpool limit allocated allocated if no reserve
1668 chg
= vma_needs_reservation(h
, vma
, addr
);
1670 return ERR_PTR(-ENOMEM
);
1671 if (chg
|| avoid_reserve
)
1672 if (hugepage_subpool_get_pages(spool
, 1) < 0) {
1673 vma_abort_reservation(h
, vma
, addr
);
1674 return ERR_PTR(-ENOSPC
);
1677 ret
= hugetlb_cgroup_charge_cgroup(idx
, pages_per_huge_page(h
), &h_cg
);
1679 goto out_subpool_put
;
1681 spin_lock(&hugetlb_lock
);
1682 page
= dequeue_huge_page_vma(h
, vma
, addr
, avoid_reserve
, chg
);
1684 spin_unlock(&hugetlb_lock
);
1685 page
= alloc_buddy_huge_page(h
, NUMA_NO_NODE
);
1687 goto out_uncharge_cgroup
;
1689 spin_lock(&hugetlb_lock
);
1690 list_move(&page
->lru
, &h
->hugepage_activelist
);
1693 hugetlb_cgroup_commit_charge(idx
, pages_per_huge_page(h
), h_cg
, page
);
1694 spin_unlock(&hugetlb_lock
);
1696 set_page_private(page
, (unsigned long)spool
);
1698 commit
= vma_commit_reservation(h
, vma
, addr
);
1699 if (unlikely(chg
> commit
)) {
1701 * The page was added to the reservation map between
1702 * vma_needs_reservation and vma_commit_reservation.
1703 * This indicates a race with hugetlb_reserve_pages.
1704 * Adjust for the subpool count incremented above AND
1705 * in hugetlb_reserve_pages for the same page. Also,
1706 * the reservation count added in hugetlb_reserve_pages
1707 * no longer applies.
1711 rsv_adjust
= hugepage_subpool_put_pages(spool
, 1);
1712 hugetlb_acct_memory(h
, -rsv_adjust
);
1716 out_uncharge_cgroup
:
1717 hugetlb_cgroup_uncharge_cgroup(idx
, pages_per_huge_page(h
), h_cg
);
1719 if (chg
|| avoid_reserve
)
1720 hugepage_subpool_put_pages(spool
, 1);
1721 vma_abort_reservation(h
, vma
, addr
);
1722 return ERR_PTR(-ENOSPC
);
1726 * alloc_huge_page()'s wrapper which simply returns the page if allocation
1727 * succeeds, otherwise NULL. This function is called from new_vma_page(),
1728 * where no ERR_VALUE is expected to be returned.
1730 struct page
*alloc_huge_page_noerr(struct vm_area_struct
*vma
,
1731 unsigned long addr
, int avoid_reserve
)
1733 struct page
*page
= alloc_huge_page(vma
, addr
, avoid_reserve
);
1739 int __weak
alloc_bootmem_huge_page(struct hstate
*h
)
1741 struct huge_bootmem_page
*m
;
1744 for_each_node_mask_to_alloc(h
, nr_nodes
, node
, &node_states
[N_MEMORY
]) {
1747 addr
= memblock_virt_alloc_try_nid_nopanic(
1748 huge_page_size(h
), huge_page_size(h
),
1749 0, BOOTMEM_ALLOC_ACCESSIBLE
, node
);
1752 * Use the beginning of the huge page to store the
1753 * huge_bootmem_page struct (until gather_bootmem
1754 * puts them into the mem_map).
1763 BUG_ON(!IS_ALIGNED(virt_to_phys(m
), huge_page_size(h
)));
1764 /* Put them into a private list first because mem_map is not up yet */
1765 list_add(&m
->list
, &huge_boot_pages
);
1770 static void __init
prep_compound_huge_page(struct page
*page
, int order
)
1772 if (unlikely(order
> (MAX_ORDER
- 1)))
1773 prep_compound_gigantic_page(page
, order
);
1775 prep_compound_page(page
, order
);
1778 /* Put bootmem huge pages into the standard lists after mem_map is up */
1779 static void __init
gather_bootmem_prealloc(void)
1781 struct huge_bootmem_page
*m
;
1783 list_for_each_entry(m
, &huge_boot_pages
, list
) {
1784 struct hstate
*h
= m
->hstate
;
1787 #ifdef CONFIG_HIGHMEM
1788 page
= pfn_to_page(m
->phys
>> PAGE_SHIFT
);
1789 memblock_free_late(__pa(m
),
1790 sizeof(struct huge_bootmem_page
));
1792 page
= virt_to_page(m
);
1794 WARN_ON(page_count(page
) != 1);
1795 prep_compound_huge_page(page
, h
->order
);
1796 WARN_ON(PageReserved(page
));
1797 prep_new_huge_page(h
, page
, page_to_nid(page
));
1799 * If we had gigantic hugepages allocated at boot time, we need
1800 * to restore the 'stolen' pages to totalram_pages in order to
1801 * fix confusing memory reports from free(1) and another
1802 * side-effects, like CommitLimit going negative.
1804 if (hstate_is_gigantic(h
))
1805 adjust_managed_page_count(page
, 1 << h
->order
);
1809 static void __init
hugetlb_hstate_alloc_pages(struct hstate
*h
)
1813 for (i
= 0; i
< h
->max_huge_pages
; ++i
) {
1814 if (hstate_is_gigantic(h
)) {
1815 if (!alloc_bootmem_huge_page(h
))
1817 } else if (!alloc_fresh_huge_page(h
,
1818 &node_states
[N_MEMORY
]))
1821 h
->max_huge_pages
= i
;
1824 static void __init
hugetlb_init_hstates(void)
1828 for_each_hstate(h
) {
1829 if (minimum_order
> huge_page_order(h
))
1830 minimum_order
= huge_page_order(h
);
1832 /* oversize hugepages were init'ed in early boot */
1833 if (!hstate_is_gigantic(h
))
1834 hugetlb_hstate_alloc_pages(h
);
1836 VM_BUG_ON(minimum_order
== UINT_MAX
);
1839 static char * __init
memfmt(char *buf
, unsigned long n
)
1841 if (n
>= (1UL << 30))
1842 sprintf(buf
, "%lu GB", n
>> 30);
1843 else if (n
>= (1UL << 20))
1844 sprintf(buf
, "%lu MB", n
>> 20);
1846 sprintf(buf
, "%lu KB", n
>> 10);
1850 static void __init
report_hugepages(void)
1854 for_each_hstate(h
) {
1856 pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n",
1857 memfmt(buf
, huge_page_size(h
)),
1858 h
->free_huge_pages
);
1862 #ifdef CONFIG_HIGHMEM
1863 static void try_to_free_low(struct hstate
*h
, unsigned long count
,
1864 nodemask_t
*nodes_allowed
)
1868 if (hstate_is_gigantic(h
))
1871 for_each_node_mask(i
, *nodes_allowed
) {
1872 struct page
*page
, *next
;
1873 struct list_head
*freel
= &h
->hugepage_freelists
[i
];
1874 list_for_each_entry_safe(page
, next
, freel
, lru
) {
1875 if (count
>= h
->nr_huge_pages
)
1877 if (PageHighMem(page
))
1879 list_del(&page
->lru
);
1880 update_and_free_page(h
, page
);
1881 h
->free_huge_pages
--;
1882 h
->free_huge_pages_node
[page_to_nid(page
)]--;
1887 static inline void try_to_free_low(struct hstate
*h
, unsigned long count
,
1888 nodemask_t
*nodes_allowed
)
1894 * Increment or decrement surplus_huge_pages. Keep node-specific counters
1895 * balanced by operating on them in a round-robin fashion.
1896 * Returns 1 if an adjustment was made.
1898 static int adjust_pool_surplus(struct hstate
*h
, nodemask_t
*nodes_allowed
,
1903 VM_BUG_ON(delta
!= -1 && delta
!= 1);
1906 for_each_node_mask_to_alloc(h
, nr_nodes
, node
, nodes_allowed
) {
1907 if (h
->surplus_huge_pages_node
[node
])
1911 for_each_node_mask_to_free(h
, nr_nodes
, node
, nodes_allowed
) {
1912 if (h
->surplus_huge_pages_node
[node
] <
1913 h
->nr_huge_pages_node
[node
])
1920 h
->surplus_huge_pages
+= delta
;
1921 h
->surplus_huge_pages_node
[node
] += delta
;
1925 #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)
1926 static unsigned long set_max_huge_pages(struct hstate
*h
, unsigned long count
,
1927 nodemask_t
*nodes_allowed
)
1929 unsigned long min_count
, ret
;
1931 if (hstate_is_gigantic(h
) && !gigantic_page_supported())
1932 return h
->max_huge_pages
;
1935 * Increase the pool size
1936 * First take pages out of surplus state. Then make up the
1937 * remaining difference by allocating fresh huge pages.
1939 * We might race with alloc_buddy_huge_page() here and be unable
1940 * to convert a surplus huge page to a normal huge page. That is
1941 * not critical, though, it just means the overall size of the
1942 * pool might be one hugepage larger than it needs to be, but
1943 * within all the constraints specified by the sysctls.
1945 spin_lock(&hugetlb_lock
);
1946 while (h
->surplus_huge_pages
&& count
> persistent_huge_pages(h
)) {
1947 if (!adjust_pool_surplus(h
, nodes_allowed
, -1))
1951 while (count
> persistent_huge_pages(h
)) {
1953 * If this allocation races such that we no longer need the
1954 * page, free_huge_page will handle it by freeing the page
1955 * and reducing the surplus.
1957 spin_unlock(&hugetlb_lock
);
1958 if (hstate_is_gigantic(h
))
1959 ret
= alloc_fresh_gigantic_page(h
, nodes_allowed
);
1961 ret
= alloc_fresh_huge_page(h
, nodes_allowed
);
1962 spin_lock(&hugetlb_lock
);
1966 /* Bail for signals. Probably ctrl-c from user */
1967 if (signal_pending(current
))
1972 * Decrease the pool size
1973 * First return free pages to the buddy allocator (being careful
1974 * to keep enough around to satisfy reservations). Then place
1975 * pages into surplus state as needed so the pool will shrink
1976 * to the desired size as pages become free.
1978 * By placing pages into the surplus state independent of the
1979 * overcommit value, we are allowing the surplus pool size to
1980 * exceed overcommit. There are few sane options here. Since
1981 * alloc_buddy_huge_page() is checking the global counter,
1982 * though, we'll note that we're not allowed to exceed surplus
1983 * and won't grow the pool anywhere else. Not until one of the
1984 * sysctls are changed, or the surplus pages go out of use.
1986 min_count
= h
->resv_huge_pages
+ h
->nr_huge_pages
- h
->free_huge_pages
;
1987 min_count
= max(count
, min_count
);
1988 try_to_free_low(h
, min_count
, nodes_allowed
);
1989 while (min_count
< persistent_huge_pages(h
)) {
1990 if (!free_pool_huge_page(h
, nodes_allowed
, 0))
1992 cond_resched_lock(&hugetlb_lock
);
1994 while (count
< persistent_huge_pages(h
)) {
1995 if (!adjust_pool_surplus(h
, nodes_allowed
, 1))
1999 ret
= persistent_huge_pages(h
);
2000 spin_unlock(&hugetlb_lock
);
2004 #define HSTATE_ATTR_RO(_name) \
2005 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
2007 #define HSTATE_ATTR(_name) \
2008 static struct kobj_attribute _name##_attr = \
2009 __ATTR(_name, 0644, _name##_show, _name##_store)
2011 static struct kobject
*hugepages_kobj
;
2012 static struct kobject
*hstate_kobjs
[HUGE_MAX_HSTATE
];
2014 static struct hstate
*kobj_to_node_hstate(struct kobject
*kobj
, int *nidp
);
2016 static struct hstate
*kobj_to_hstate(struct kobject
*kobj
, int *nidp
)
2020 for (i
= 0; i
< HUGE_MAX_HSTATE
; i
++)
2021 if (hstate_kobjs
[i
] == kobj
) {
2023 *nidp
= NUMA_NO_NODE
;
2027 return kobj_to_node_hstate(kobj
, nidp
);
2030 static ssize_t
nr_hugepages_show_common(struct kobject
*kobj
,
2031 struct kobj_attribute
*attr
, char *buf
)
2034 unsigned long nr_huge_pages
;
2037 h
= kobj_to_hstate(kobj
, &nid
);
2038 if (nid
== NUMA_NO_NODE
)
2039 nr_huge_pages
= h
->nr_huge_pages
;
2041 nr_huge_pages
= h
->nr_huge_pages_node
[nid
];
2043 return sprintf(buf
, "%lu\n", nr_huge_pages
);
2046 static ssize_t
__nr_hugepages_store_common(bool obey_mempolicy
,
2047 struct hstate
*h
, int nid
,
2048 unsigned long count
, size_t len
)
2051 NODEMASK_ALLOC(nodemask_t
, nodes_allowed
, GFP_KERNEL
| __GFP_NORETRY
);
2053 if (hstate_is_gigantic(h
) && !gigantic_page_supported()) {
2058 if (nid
== NUMA_NO_NODE
) {
2060 * global hstate attribute
2062 if (!(obey_mempolicy
&&
2063 init_nodemask_of_mempolicy(nodes_allowed
))) {
2064 NODEMASK_FREE(nodes_allowed
);
2065 nodes_allowed
= &node_states
[N_MEMORY
];
2067 } else if (nodes_allowed
) {
2069 * per node hstate attribute: adjust count to global,
2070 * but restrict alloc/free to the specified node.
2072 count
+= h
->nr_huge_pages
- h
->nr_huge_pages_node
[nid
];
2073 init_nodemask_of_node(nodes_allowed
, nid
);
2075 nodes_allowed
= &node_states
[N_MEMORY
];
2077 h
->max_huge_pages
= set_max_huge_pages(h
, count
, nodes_allowed
);
2079 if (nodes_allowed
!= &node_states
[N_MEMORY
])
2080 NODEMASK_FREE(nodes_allowed
);
2084 NODEMASK_FREE(nodes_allowed
);
2088 static ssize_t
nr_hugepages_store_common(bool obey_mempolicy
,
2089 struct kobject
*kobj
, const char *buf
,
2093 unsigned long count
;
2097 err
= kstrtoul(buf
, 10, &count
);
2101 h
= kobj_to_hstate(kobj
, &nid
);
2102 return __nr_hugepages_store_common(obey_mempolicy
, h
, nid
, count
, len
);
2105 static ssize_t
nr_hugepages_show(struct kobject
*kobj
,
2106 struct kobj_attribute
*attr
, char *buf
)
2108 return nr_hugepages_show_common(kobj
, attr
, buf
);
2111 static ssize_t
nr_hugepages_store(struct kobject
*kobj
,
2112 struct kobj_attribute
*attr
, const char *buf
, size_t len
)
2114 return nr_hugepages_store_common(false, kobj
, buf
, len
);
2116 HSTATE_ATTR(nr_hugepages
);
2121 * hstate attribute for optionally mempolicy-based constraint on persistent
2122 * huge page alloc/free.
2124 static ssize_t
nr_hugepages_mempolicy_show(struct kobject
*kobj
,
2125 struct kobj_attribute
*attr
, char *buf
)
2127 return nr_hugepages_show_common(kobj
, attr
, buf
);
2130 static ssize_t
nr_hugepages_mempolicy_store(struct kobject
*kobj
,
2131 struct kobj_attribute
*attr
, const char *buf
, size_t len
)
2133 return nr_hugepages_store_common(true, kobj
, buf
, len
);
2135 HSTATE_ATTR(nr_hugepages_mempolicy
);
2139 static ssize_t
nr_overcommit_hugepages_show(struct kobject
*kobj
,
2140 struct kobj_attribute
*attr
, char *buf
)
2142 struct hstate
*h
= kobj_to_hstate(kobj
, NULL
);
2143 return sprintf(buf
, "%lu\n", h
->nr_overcommit_huge_pages
);
2146 static ssize_t
nr_overcommit_hugepages_store(struct kobject
*kobj
,
2147 struct kobj_attribute
*attr
, const char *buf
, size_t count
)
2150 unsigned long input
;
2151 struct hstate
*h
= kobj_to_hstate(kobj
, NULL
);
2153 if (hstate_is_gigantic(h
))
2156 err
= kstrtoul(buf
, 10, &input
);
2160 spin_lock(&hugetlb_lock
);
2161 h
->nr_overcommit_huge_pages
= input
;
2162 spin_unlock(&hugetlb_lock
);
2166 HSTATE_ATTR(nr_overcommit_hugepages
);
2168 static ssize_t
free_hugepages_show(struct kobject
*kobj
,
2169 struct kobj_attribute
*attr
, char *buf
)
2172 unsigned long free_huge_pages
;
2175 h
= kobj_to_hstate(kobj
, &nid
);
2176 if (nid
== NUMA_NO_NODE
)
2177 free_huge_pages
= h
->free_huge_pages
;
2179 free_huge_pages
= h
->free_huge_pages_node
[nid
];
2181 return sprintf(buf
, "%lu\n", free_huge_pages
);
2183 HSTATE_ATTR_RO(free_hugepages
);
2185 static ssize_t
resv_hugepages_show(struct kobject
*kobj
,
2186 struct kobj_attribute
*attr
, char *buf
)
2188 struct hstate
*h
= kobj_to_hstate(kobj
, NULL
);
2189 return sprintf(buf
, "%lu\n", h
->resv_huge_pages
);
2191 HSTATE_ATTR_RO(resv_hugepages
);
2193 static ssize_t
surplus_hugepages_show(struct kobject
*kobj
,
2194 struct kobj_attribute
*attr
, char *buf
)
2197 unsigned long surplus_huge_pages
;
2200 h
= kobj_to_hstate(kobj
, &nid
);
2201 if (nid
== NUMA_NO_NODE
)
2202 surplus_huge_pages
= h
->surplus_huge_pages
;
2204 surplus_huge_pages
= h
->surplus_huge_pages_node
[nid
];
2206 return sprintf(buf
, "%lu\n", surplus_huge_pages
);
2208 HSTATE_ATTR_RO(surplus_hugepages
);
2210 static struct attribute
*hstate_attrs
[] = {
2211 &nr_hugepages_attr
.attr
,
2212 &nr_overcommit_hugepages_attr
.attr
,
2213 &free_hugepages_attr
.attr
,
2214 &resv_hugepages_attr
.attr
,
2215 &surplus_hugepages_attr
.attr
,
2217 &nr_hugepages_mempolicy_attr
.attr
,
2222 static struct attribute_group hstate_attr_group
= {
2223 .attrs
= hstate_attrs
,
2226 static int hugetlb_sysfs_add_hstate(struct hstate
*h
, struct kobject
*parent
,
2227 struct kobject
**hstate_kobjs
,
2228 struct attribute_group
*hstate_attr_group
)
2231 int hi
= hstate_index(h
);
2233 hstate_kobjs
[hi
] = kobject_create_and_add(h
->name
, parent
);
2234 if (!hstate_kobjs
[hi
])
2237 retval
= sysfs_create_group(hstate_kobjs
[hi
], hstate_attr_group
);
2239 kobject_put(hstate_kobjs
[hi
]);
2244 static void __init
hugetlb_sysfs_init(void)
2249 hugepages_kobj
= kobject_create_and_add("hugepages", mm_kobj
);
2250 if (!hugepages_kobj
)
2253 for_each_hstate(h
) {
2254 err
= hugetlb_sysfs_add_hstate(h
, hugepages_kobj
,
2255 hstate_kobjs
, &hstate_attr_group
);
2257 pr_err("Hugetlb: Unable to add hstate %s", h
->name
);
2264 * node_hstate/s - associate per node hstate attributes, via their kobjects,
2265 * with node devices in node_devices[] using a parallel array. The array
2266 * index of a node device or _hstate == node id.
2267 * This is here to avoid any static dependency of the node device driver, in
2268 * the base kernel, on the hugetlb module.
2270 struct node_hstate
{
2271 struct kobject
*hugepages_kobj
;
2272 struct kobject
*hstate_kobjs
[HUGE_MAX_HSTATE
];
2274 struct node_hstate node_hstates
[MAX_NUMNODES
];
2277 * A subset of global hstate attributes for node devices
2279 static struct attribute
*per_node_hstate_attrs
[] = {
2280 &nr_hugepages_attr
.attr
,
2281 &free_hugepages_attr
.attr
,
2282 &surplus_hugepages_attr
.attr
,
2286 static struct attribute_group per_node_hstate_attr_group
= {
2287 .attrs
= per_node_hstate_attrs
,
2291 * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj.
2292 * Returns node id via non-NULL nidp.
2294 static struct hstate
*kobj_to_node_hstate(struct kobject
*kobj
, int *nidp
)
2298 for (nid
= 0; nid
< nr_node_ids
; nid
++) {
2299 struct node_hstate
*nhs
= &node_hstates
[nid
];
2301 for (i
= 0; i
< HUGE_MAX_HSTATE
; i
++)
2302 if (nhs
->hstate_kobjs
[i
] == kobj
) {
2314 * Unregister hstate attributes from a single node device.
2315 * No-op if no hstate attributes attached.
2317 static void hugetlb_unregister_node(struct node
*node
)
2320 struct node_hstate
*nhs
= &node_hstates
[node
->dev
.id
];
2322 if (!nhs
->hugepages_kobj
)
2323 return; /* no hstate attributes */
2325 for_each_hstate(h
) {
2326 int idx
= hstate_index(h
);
2327 if (nhs
->hstate_kobjs
[idx
]) {
2328 kobject_put(nhs
->hstate_kobjs
[idx
]);
2329 nhs
->hstate_kobjs
[idx
] = NULL
;
2333 kobject_put(nhs
->hugepages_kobj
);
2334 nhs
->hugepages_kobj
= NULL
;
2338 * hugetlb module exit: unregister hstate attributes from node devices
2341 static void hugetlb_unregister_all_nodes(void)
2346 * disable node device registrations.
2348 register_hugetlbfs_with_node(NULL
, NULL
);
2351 * remove hstate attributes from any nodes that have them.
2353 for (nid
= 0; nid
< nr_node_ids
; nid
++)
2354 hugetlb_unregister_node(node_devices
[nid
]);
2358 * Register hstate attributes for a single node device.
2359 * No-op if attributes already registered.
2361 static void hugetlb_register_node(struct node
*node
)
2364 struct node_hstate
*nhs
= &node_hstates
[node
->dev
.id
];
2367 if (nhs
->hugepages_kobj
)
2368 return; /* already allocated */
2370 nhs
->hugepages_kobj
= kobject_create_and_add("hugepages",
2372 if (!nhs
->hugepages_kobj
)
2375 for_each_hstate(h
) {
2376 err
= hugetlb_sysfs_add_hstate(h
, nhs
->hugepages_kobj
,
2378 &per_node_hstate_attr_group
);
2380 pr_err("Hugetlb: Unable to add hstate %s for node %d\n",
2381 h
->name
, node
->dev
.id
);
2382 hugetlb_unregister_node(node
);
2389 * hugetlb init time: register hstate attributes for all registered node
2390 * devices of nodes that have memory. All on-line nodes should have
2391 * registered their associated device by this time.
2393 static void __init
hugetlb_register_all_nodes(void)
2397 for_each_node_state(nid
, N_MEMORY
) {
2398 struct node
*node
= node_devices
[nid
];
2399 if (node
->dev
.id
== nid
)
2400 hugetlb_register_node(node
);
2404 * Let the node device driver know we're here so it can
2405 * [un]register hstate attributes on node hotplug.
2407 register_hugetlbfs_with_node(hugetlb_register_node
,
2408 hugetlb_unregister_node
);
2410 #else /* !CONFIG_NUMA */
2412 static struct hstate
*kobj_to_node_hstate(struct kobject
*kobj
, int *nidp
)
2420 static void hugetlb_unregister_all_nodes(void) { }
2422 static void hugetlb_register_all_nodes(void) { }
2426 static void __exit
hugetlb_exit(void)
2430 hugetlb_unregister_all_nodes();
2432 for_each_hstate(h
) {
2433 kobject_put(hstate_kobjs
[hstate_index(h
)]);
2436 kobject_put(hugepages_kobj
);
2437 kfree(htlb_fault_mutex_table
);
2439 module_exit(hugetlb_exit
);
2441 static int __init
hugetlb_init(void)
2445 if (!hugepages_supported())
2448 if (!size_to_hstate(default_hstate_size
)) {
2449 default_hstate_size
= HPAGE_SIZE
;
2450 if (!size_to_hstate(default_hstate_size
))
2451 hugetlb_add_hstate(HUGETLB_PAGE_ORDER
);
2453 default_hstate_idx
= hstate_index(size_to_hstate(default_hstate_size
));
2454 if (default_hstate_max_huge_pages
)
2455 default_hstate
.max_huge_pages
= default_hstate_max_huge_pages
;
2457 hugetlb_init_hstates();
2458 gather_bootmem_prealloc();
2461 hugetlb_sysfs_init();
2462 hugetlb_register_all_nodes();
2463 hugetlb_cgroup_file_init();
2466 num_fault_mutexes
= roundup_pow_of_two(8 * num_possible_cpus());
2468 num_fault_mutexes
= 1;
2470 htlb_fault_mutex_table
=
2471 kmalloc(sizeof(struct mutex
) * num_fault_mutexes
, GFP_KERNEL
);
2472 BUG_ON(!htlb_fault_mutex_table
);
2474 for (i
= 0; i
< num_fault_mutexes
; i
++)
2475 mutex_init(&htlb_fault_mutex_table
[i
]);
2478 module_init(hugetlb_init
);
2480 /* Should be called on processing a hugepagesz=... option */
2481 void __init
hugetlb_add_hstate(unsigned order
)
2486 if (size_to_hstate(PAGE_SIZE
<< order
)) {
2487 pr_warning("hugepagesz= specified twice, ignoring\n");
2490 BUG_ON(hugetlb_max_hstate
>= HUGE_MAX_HSTATE
);
2492 h
= &hstates
[hugetlb_max_hstate
++];
2494 h
->mask
= ~((1ULL << (order
+ PAGE_SHIFT
)) - 1);
2495 h
->nr_huge_pages
= 0;
2496 h
->free_huge_pages
= 0;
2497 for (i
= 0; i
< MAX_NUMNODES
; ++i
)
2498 INIT_LIST_HEAD(&h
->hugepage_freelists
[i
]);
2499 INIT_LIST_HEAD(&h
->hugepage_activelist
);
2500 h
->next_nid_to_alloc
= first_node(node_states
[N_MEMORY
]);
2501 h
->next_nid_to_free
= first_node(node_states
[N_MEMORY
]);
2502 snprintf(h
->name
, HSTATE_NAME_LEN
, "hugepages-%lukB",
2503 huge_page_size(h
)/1024);
2508 static int __init
hugetlb_nrpages_setup(char *s
)
2511 static unsigned long *last_mhp
;
2514 * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter yet,
2515 * so this hugepages= parameter goes to the "default hstate".
2517 if (!hugetlb_max_hstate
)
2518 mhp
= &default_hstate_max_huge_pages
;
2520 mhp
= &parsed_hstate
->max_huge_pages
;
2522 if (mhp
== last_mhp
) {
2523 pr_warning("hugepages= specified twice without "
2524 "interleaving hugepagesz=, ignoring\n");
2528 if (sscanf(s
, "%lu", mhp
) <= 0)
2532 * Global state is always initialized later in hugetlb_init.
2533 * But we need to allocate >= MAX_ORDER hstates here early to still
2534 * use the bootmem allocator.
2536 if (hugetlb_max_hstate
&& parsed_hstate
->order
>= MAX_ORDER
)
2537 hugetlb_hstate_alloc_pages(parsed_hstate
);
2543 __setup("hugepages=", hugetlb_nrpages_setup
);
2545 static int __init
hugetlb_default_setup(char *s
)
2547 default_hstate_size
= memparse(s
, &s
);
2550 __setup("default_hugepagesz=", hugetlb_default_setup
);
2552 static unsigned int cpuset_mems_nr(unsigned int *array
)
2555 unsigned int nr
= 0;
2557 for_each_node_mask(node
, cpuset_current_mems_allowed
)
2563 #ifdef CONFIG_SYSCTL
2564 static int hugetlb_sysctl_handler_common(bool obey_mempolicy
,
2565 struct ctl_table
*table
, int write
,
2566 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
2568 struct hstate
*h
= &default_hstate
;
2569 unsigned long tmp
= h
->max_huge_pages
;
2572 if (!hugepages_supported())
2576 table
->maxlen
= sizeof(unsigned long);
2577 ret
= proc_doulongvec_minmax(table
, write
, buffer
, length
, ppos
);
2582 ret
= __nr_hugepages_store_common(obey_mempolicy
, h
,
2583 NUMA_NO_NODE
, tmp
, *length
);
2588 int hugetlb_sysctl_handler(struct ctl_table
*table
, int write
,
2589 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
2592 return hugetlb_sysctl_handler_common(false, table
, write
,
2593 buffer
, length
, ppos
);
2597 int hugetlb_mempolicy_sysctl_handler(struct ctl_table
*table
, int write
,
2598 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
2600 return hugetlb_sysctl_handler_common(true, table
, write
,
2601 buffer
, length
, ppos
);
2603 #endif /* CONFIG_NUMA */
2605 int hugetlb_overcommit_handler(struct ctl_table
*table
, int write
,
2606 void __user
*buffer
,
2607 size_t *length
, loff_t
*ppos
)
2609 struct hstate
*h
= &default_hstate
;
2613 if (!hugepages_supported())
2616 tmp
= h
->nr_overcommit_huge_pages
;
2618 if (write
&& hstate_is_gigantic(h
))
2622 table
->maxlen
= sizeof(unsigned long);
2623 ret
= proc_doulongvec_minmax(table
, write
, buffer
, length
, ppos
);
2628 spin_lock(&hugetlb_lock
);
2629 h
->nr_overcommit_huge_pages
= tmp
;
2630 spin_unlock(&hugetlb_lock
);
2636 #endif /* CONFIG_SYSCTL */
2638 void hugetlb_report_meminfo(struct seq_file
*m
)
2640 struct hstate
*h
= &default_hstate
;
2641 if (!hugepages_supported())
2644 "HugePages_Total: %5lu\n"
2645 "HugePages_Free: %5lu\n"
2646 "HugePages_Rsvd: %5lu\n"
2647 "HugePages_Surp: %5lu\n"
2648 "Hugepagesize: %8lu kB\n",
2652 h
->surplus_huge_pages
,
2653 1UL << (huge_page_order(h
) + PAGE_SHIFT
- 10));
2656 int hugetlb_report_node_meminfo(int nid
, char *buf
)
2658 struct hstate
*h
= &default_hstate
;
2659 if (!hugepages_supported())
2662 "Node %d HugePages_Total: %5u\n"
2663 "Node %d HugePages_Free: %5u\n"
2664 "Node %d HugePages_Surp: %5u\n",
2665 nid
, h
->nr_huge_pages_node
[nid
],
2666 nid
, h
->free_huge_pages_node
[nid
],
2667 nid
, h
->surplus_huge_pages_node
[nid
]);
2670 void hugetlb_show_meminfo(void)
2675 if (!hugepages_supported())
2678 for_each_node_state(nid
, N_MEMORY
)
2680 pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n",
2682 h
->nr_huge_pages_node
[nid
],
2683 h
->free_huge_pages_node
[nid
],
2684 h
->surplus_huge_pages_node
[nid
],
2685 1UL << (huge_page_order(h
) + PAGE_SHIFT
- 10));
2688 /* Return the number pages of memory we physically have, in PAGE_SIZE units. */
2689 unsigned long hugetlb_total_pages(void)
2692 unsigned long nr_total_pages
= 0;
2695 nr_total_pages
+= h
->nr_huge_pages
* pages_per_huge_page(h
);
2696 return nr_total_pages
;
2699 static int hugetlb_acct_memory(struct hstate
*h
, long delta
)
2703 spin_lock(&hugetlb_lock
);
2705 * When cpuset is configured, it breaks the strict hugetlb page
2706 * reservation as the accounting is done on a global variable. Such
2707 * reservation is completely rubbish in the presence of cpuset because
2708 * the reservation is not checked against page availability for the
2709 * current cpuset. Application can still potentially OOM'ed by kernel
2710 * with lack of free htlb page in cpuset that the task is in.
2711 * Attempt to enforce strict accounting with cpuset is almost
2712 * impossible (or too ugly) because cpuset is too fluid that
2713 * task or memory node can be dynamically moved between cpusets.
2715 * The change of semantics for shared hugetlb mapping with cpuset is
2716 * undesirable. However, in order to preserve some of the semantics,
2717 * we fall back to check against current free page availability as
2718 * a best attempt and hopefully to minimize the impact of changing
2719 * semantics that cpuset has.
2722 if (gather_surplus_pages(h
, delta
) < 0)
2725 if (delta
> cpuset_mems_nr(h
->free_huge_pages_node
)) {
2726 return_unused_surplus_pages(h
, delta
);
2733 return_unused_surplus_pages(h
, (unsigned long) -delta
);
2736 spin_unlock(&hugetlb_lock
);
2740 static void hugetlb_vm_op_open(struct vm_area_struct
*vma
)
2742 struct resv_map
*resv
= vma_resv_map(vma
);
2745 * This new VMA should share its siblings reservation map if present.
2746 * The VMA will only ever have a valid reservation map pointer where
2747 * it is being copied for another still existing VMA. As that VMA
2748 * has a reference to the reservation map it cannot disappear until
2749 * after this open call completes. It is therefore safe to take a
2750 * new reference here without additional locking.
2752 if (resv
&& is_vma_resv_set(vma
, HPAGE_RESV_OWNER
))
2753 kref_get(&resv
->refs
);
2756 static void hugetlb_vm_op_close(struct vm_area_struct
*vma
)
2758 struct hstate
*h
= hstate_vma(vma
);
2759 struct resv_map
*resv
= vma_resv_map(vma
);
2760 struct hugepage_subpool
*spool
= subpool_vma(vma
);
2761 unsigned long reserve
, start
, end
;
2764 if (!resv
|| !is_vma_resv_set(vma
, HPAGE_RESV_OWNER
))
2767 start
= vma_hugecache_offset(h
, vma
, vma
->vm_start
);
2768 end
= vma_hugecache_offset(h
, vma
, vma
->vm_end
);
2770 reserve
= (end
- start
) - region_count(resv
, start
, end
);
2772 kref_put(&resv
->refs
, resv_map_release
);
2776 * Decrement reserve counts. The global reserve count may be
2777 * adjusted if the subpool has a minimum size.
2779 gbl_reserve
= hugepage_subpool_put_pages(spool
, reserve
);
2780 hugetlb_acct_memory(h
, -gbl_reserve
);
2785 * We cannot handle pagefaults against hugetlb pages at all. They cause
2786 * handle_mm_fault() to try to instantiate regular-sized pages in the
2787 * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get
2790 static int hugetlb_vm_op_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
2796 const struct vm_operations_struct hugetlb_vm_ops
= {
2797 .fault
= hugetlb_vm_op_fault
,
2798 .open
= hugetlb_vm_op_open
,
2799 .close
= hugetlb_vm_op_close
,
2802 static pte_t
make_huge_pte(struct vm_area_struct
*vma
, struct page
*page
,
2808 entry
= huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page
,
2809 vma
->vm_page_prot
)));
2811 entry
= huge_pte_wrprotect(mk_huge_pte(page
,
2812 vma
->vm_page_prot
));
2814 entry
= pte_mkyoung(entry
);
2815 entry
= pte_mkhuge(entry
);
2816 entry
= arch_make_huge_pte(entry
, vma
, page
, writable
);
2821 static void set_huge_ptep_writable(struct vm_area_struct
*vma
,
2822 unsigned long address
, pte_t
*ptep
)
2826 entry
= huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep
)));
2827 if (huge_ptep_set_access_flags(vma
, address
, ptep
, entry
, 1))
2828 update_mmu_cache(vma
, address
, ptep
);
2831 static int is_hugetlb_entry_migration(pte_t pte
)
2835 if (huge_pte_none(pte
) || pte_present(pte
))
2837 swp
= pte_to_swp_entry(pte
);
2838 if (non_swap_entry(swp
) && is_migration_entry(swp
))
2844 static int is_hugetlb_entry_hwpoisoned(pte_t pte
)
2848 if (huge_pte_none(pte
) || pte_present(pte
))
2850 swp
= pte_to_swp_entry(pte
);
2851 if (non_swap_entry(swp
) && is_hwpoison_entry(swp
))
2857 int copy_hugetlb_page_range(struct mm_struct
*dst
, struct mm_struct
*src
,
2858 struct vm_area_struct
*vma
)
2860 pte_t
*src_pte
, *dst_pte
, entry
;
2861 struct page
*ptepage
;
2864 struct hstate
*h
= hstate_vma(vma
);
2865 unsigned long sz
= huge_page_size(h
);
2866 unsigned long mmun_start
; /* For mmu_notifiers */
2867 unsigned long mmun_end
; /* For mmu_notifiers */
2870 cow
= (vma
->vm_flags
& (VM_SHARED
| VM_MAYWRITE
)) == VM_MAYWRITE
;
2872 mmun_start
= vma
->vm_start
;
2873 mmun_end
= vma
->vm_end
;
2875 mmu_notifier_invalidate_range_start(src
, mmun_start
, mmun_end
);
2877 for (addr
= vma
->vm_start
; addr
< vma
->vm_end
; addr
+= sz
) {
2878 spinlock_t
*src_ptl
, *dst_ptl
;
2879 src_pte
= huge_pte_offset(src
, addr
);
2882 dst_pte
= huge_pte_alloc(dst
, addr
, sz
);
2888 /* If the pagetables are shared don't copy or take references */
2889 if (dst_pte
== src_pte
)
2892 dst_ptl
= huge_pte_lock(h
, dst
, dst_pte
);
2893 src_ptl
= huge_pte_lockptr(h
, src
, src_pte
);
2894 spin_lock_nested(src_ptl
, SINGLE_DEPTH_NESTING
);
2895 entry
= huge_ptep_get(src_pte
);
2896 if (huge_pte_none(entry
)) { /* skip none entry */
2898 } else if (unlikely(is_hugetlb_entry_migration(entry
) ||
2899 is_hugetlb_entry_hwpoisoned(entry
))) {
2900 swp_entry_t swp_entry
= pte_to_swp_entry(entry
);
2902 if (is_write_migration_entry(swp_entry
) && cow
) {
2904 * COW mappings require pages in both
2905 * parent and child to be set to read.
2907 make_migration_entry_read(&swp_entry
);
2908 entry
= swp_entry_to_pte(swp_entry
);
2909 set_huge_pte_at(src
, addr
, src_pte
, entry
);
2911 set_huge_pte_at(dst
, addr
, dst_pte
, entry
);
2914 huge_ptep_set_wrprotect(src
, addr
, src_pte
);
2915 mmu_notifier_invalidate_range(src
, mmun_start
,
2918 entry
= huge_ptep_get(src_pte
);
2919 ptepage
= pte_page(entry
);
2921 page_dup_rmap(ptepage
);
2922 set_huge_pte_at(dst
, addr
, dst_pte
, entry
);
2924 spin_unlock(src_ptl
);
2925 spin_unlock(dst_ptl
);
2929 mmu_notifier_invalidate_range_end(src
, mmun_start
, mmun_end
);
2934 void __unmap_hugepage_range(struct mmu_gather
*tlb
, struct vm_area_struct
*vma
,
2935 unsigned long start
, unsigned long end
,
2936 struct page
*ref_page
)
2938 int force_flush
= 0;
2939 struct mm_struct
*mm
= vma
->vm_mm
;
2940 unsigned long address
;
2945 struct hstate
*h
= hstate_vma(vma
);
2946 unsigned long sz
= huge_page_size(h
);
2947 const unsigned long mmun_start
= start
; /* For mmu_notifiers */
2948 const unsigned long mmun_end
= end
; /* For mmu_notifiers */
2950 WARN_ON(!is_vm_hugetlb_page(vma
));
2951 BUG_ON(start
& ~huge_page_mask(h
));
2952 BUG_ON(end
& ~huge_page_mask(h
));
2954 tlb_start_vma(tlb
, vma
);
2955 mmu_notifier_invalidate_range_start(mm
, mmun_start
, mmun_end
);
2958 for (; address
< end
; address
+= sz
) {
2959 ptep
= huge_pte_offset(mm
, address
);
2963 ptl
= huge_pte_lock(h
, mm
, ptep
);
2964 if (huge_pmd_unshare(mm
, &address
, ptep
))
2967 pte
= huge_ptep_get(ptep
);
2968 if (huge_pte_none(pte
))
2972 * Migrating hugepage or HWPoisoned hugepage is already
2973 * unmapped and its refcount is dropped, so just clear pte here.
2975 if (unlikely(!pte_present(pte
))) {
2976 huge_pte_clear(mm
, address
, ptep
);
2980 page
= pte_page(pte
);
2982 * If a reference page is supplied, it is because a specific
2983 * page is being unmapped, not a range. Ensure the page we
2984 * are about to unmap is the actual page of interest.
2987 if (page
!= ref_page
)
2991 * Mark the VMA as having unmapped its page so that
2992 * future faults in this VMA will fail rather than
2993 * looking like data was lost
2995 set_vma_resv_flags(vma
, HPAGE_RESV_UNMAPPED
);
2998 pte
= huge_ptep_get_and_clear(mm
, address
, ptep
);
2999 tlb_remove_tlb_entry(tlb
, ptep
, address
);
3000 if (huge_pte_dirty(pte
))
3001 set_page_dirty(page
);
3003 page_remove_rmap(page
);
3004 force_flush
= !__tlb_remove_page(tlb
, page
);
3010 /* Bail out after unmapping reference page if supplied */
3019 * mmu_gather ran out of room to batch pages, we break out of
3020 * the PTE lock to avoid doing the potential expensive TLB invalidate
3021 * and page-free while holding it.
3026 if (address
< end
&& !ref_page
)
3029 mmu_notifier_invalidate_range_end(mm
, mmun_start
, mmun_end
);
3030 tlb_end_vma(tlb
, vma
);
3033 void __unmap_hugepage_range_final(struct mmu_gather
*tlb
,
3034 struct vm_area_struct
*vma
, unsigned long start
,
3035 unsigned long end
, struct page
*ref_page
)
3037 __unmap_hugepage_range(tlb
, vma
, start
, end
, ref_page
);
3040 * Clear this flag so that x86's huge_pmd_share page_table_shareable
3041 * test will fail on a vma being torn down, and not grab a page table
3042 * on its way out. We're lucky that the flag has such an appropriate
3043 * name, and can in fact be safely cleared here. We could clear it
3044 * before the __unmap_hugepage_range above, but all that's necessary
3045 * is to clear it before releasing the i_mmap_rwsem. This works
3046 * because in the context this is called, the VMA is about to be
3047 * destroyed and the i_mmap_rwsem is held.
3049 vma
->vm_flags
&= ~VM_MAYSHARE
;
3052 void unmap_hugepage_range(struct vm_area_struct
*vma
, unsigned long start
,
3053 unsigned long end
, struct page
*ref_page
)
3055 struct mm_struct
*mm
;
3056 struct mmu_gather tlb
;
3060 tlb_gather_mmu(&tlb
, mm
, start
, end
);
3061 __unmap_hugepage_range(&tlb
, vma
, start
, end
, ref_page
);
3062 tlb_finish_mmu(&tlb
, start
, end
);
3066 * This is called when the original mapper is failing to COW a MAP_PRIVATE
3067 * mappping it owns the reserve page for. The intention is to unmap the page
3068 * from other VMAs and let the children be SIGKILLed if they are faulting the
3071 static void unmap_ref_private(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
3072 struct page
*page
, unsigned long address
)
3074 struct hstate
*h
= hstate_vma(vma
);
3075 struct vm_area_struct
*iter_vma
;
3076 struct address_space
*mapping
;
3080 * vm_pgoff is in PAGE_SIZE units, hence the different calculation
3081 * from page cache lookup which is in HPAGE_SIZE units.
3083 address
= address
& huge_page_mask(h
);
3084 pgoff
= ((address
- vma
->vm_start
) >> PAGE_SHIFT
) +
3086 mapping
= file_inode(vma
->vm_file
)->i_mapping
;
3089 * Take the mapping lock for the duration of the table walk. As
3090 * this mapping should be shared between all the VMAs,
3091 * __unmap_hugepage_range() is called as the lock is already held
3093 i_mmap_lock_write(mapping
);
3094 vma_interval_tree_foreach(iter_vma
, &mapping
->i_mmap
, pgoff
, pgoff
) {
3095 /* Do not unmap the current VMA */
3096 if (iter_vma
== vma
)
3100 * Unmap the page from other VMAs without their own reserves.
3101 * They get marked to be SIGKILLed if they fault in these
3102 * areas. This is because a future no-page fault on this VMA
3103 * could insert a zeroed page instead of the data existing
3104 * from the time of fork. This would look like data corruption
3106 if (!is_vma_resv_set(iter_vma
, HPAGE_RESV_OWNER
))
3107 unmap_hugepage_range(iter_vma
, address
,
3108 address
+ huge_page_size(h
), page
);
3110 i_mmap_unlock_write(mapping
);
3114 * Hugetlb_cow() should be called with page lock of the original hugepage held.
3115 * Called with hugetlb_instantiation_mutex held and pte_page locked so we
3116 * cannot race with other handlers or page migration.
3117 * Keep the pte_same checks anyway to make transition from the mutex easier.
3119 static int hugetlb_cow(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
3120 unsigned long address
, pte_t
*ptep
, pte_t pte
,
3121 struct page
*pagecache_page
, spinlock_t
*ptl
)
3123 struct hstate
*h
= hstate_vma(vma
);
3124 struct page
*old_page
, *new_page
;
3125 int ret
= 0, outside_reserve
= 0;
3126 unsigned long mmun_start
; /* For mmu_notifiers */
3127 unsigned long mmun_end
; /* For mmu_notifiers */
3129 old_page
= pte_page(pte
);
3132 /* If no-one else is actually using this page, avoid the copy
3133 * and just make the page writable */
3134 if (page_mapcount(old_page
) == 1 && PageAnon(old_page
)) {
3135 page_move_anon_rmap(old_page
, vma
, address
);
3136 set_huge_ptep_writable(vma
, address
, ptep
);
3141 * If the process that created a MAP_PRIVATE mapping is about to
3142 * perform a COW due to a shared page count, attempt to satisfy
3143 * the allocation without using the existing reserves. The pagecache
3144 * page is used to determine if the reserve at this address was
3145 * consumed or not. If reserves were used, a partial faulted mapping
3146 * at the time of fork() could consume its reserves on COW instead
3147 * of the full address range.
3149 if (is_vma_resv_set(vma
, HPAGE_RESV_OWNER
) &&
3150 old_page
!= pagecache_page
)
3151 outside_reserve
= 1;
3153 page_cache_get(old_page
);
3156 * Drop page table lock as buddy allocator may be called. It will
3157 * be acquired again before returning to the caller, as expected.
3160 new_page
= alloc_huge_page(vma
, address
, outside_reserve
);
3162 if (IS_ERR(new_page
)) {
3164 * If a process owning a MAP_PRIVATE mapping fails to COW,
3165 * it is due to references held by a child and an insufficient
3166 * huge page pool. To guarantee the original mappers
3167 * reliability, unmap the page from child processes. The child
3168 * may get SIGKILLed if it later faults.
3170 if (outside_reserve
) {
3171 page_cache_release(old_page
);
3172 BUG_ON(huge_pte_none(pte
));
3173 unmap_ref_private(mm
, vma
, old_page
, address
);
3174 BUG_ON(huge_pte_none(pte
));
3176 ptep
= huge_pte_offset(mm
, address
& huge_page_mask(h
));
3178 pte_same(huge_ptep_get(ptep
), pte
)))
3179 goto retry_avoidcopy
;
3181 * race occurs while re-acquiring page table
3182 * lock, and our job is done.
3187 ret
= (PTR_ERR(new_page
) == -ENOMEM
) ?
3188 VM_FAULT_OOM
: VM_FAULT_SIGBUS
;
3189 goto out_release_old
;
3193 * When the original hugepage is shared one, it does not have
3194 * anon_vma prepared.
3196 if (unlikely(anon_vma_prepare(vma
))) {
3198 goto out_release_all
;
3201 copy_user_huge_page(new_page
, old_page
, address
, vma
,
3202 pages_per_huge_page(h
));
3203 __SetPageUptodate(new_page
);
3204 set_page_huge_active(new_page
);
3206 mmun_start
= address
& huge_page_mask(h
);
3207 mmun_end
= mmun_start
+ huge_page_size(h
);
3208 mmu_notifier_invalidate_range_start(mm
, mmun_start
, mmun_end
);
3211 * Retake the page table lock to check for racing updates
3212 * before the page tables are altered
3215 ptep
= huge_pte_offset(mm
, address
& huge_page_mask(h
));
3216 if (likely(ptep
&& pte_same(huge_ptep_get(ptep
), pte
))) {
3217 ClearPagePrivate(new_page
);
3220 huge_ptep_clear_flush(vma
, address
, ptep
);
3221 mmu_notifier_invalidate_range(mm
, mmun_start
, mmun_end
);
3222 set_huge_pte_at(mm
, address
, ptep
,
3223 make_huge_pte(vma
, new_page
, 1));
3224 page_remove_rmap(old_page
);
3225 hugepage_add_new_anon_rmap(new_page
, vma
, address
);
3226 /* Make the old page be freed below */
3227 new_page
= old_page
;
3230 mmu_notifier_invalidate_range_end(mm
, mmun_start
, mmun_end
);
3232 page_cache_release(new_page
);
3234 page_cache_release(old_page
);
3236 spin_lock(ptl
); /* Caller expects lock to be held */
3240 /* Return the pagecache page at a given address within a VMA */
3241 static struct page
*hugetlbfs_pagecache_page(struct hstate
*h
,
3242 struct vm_area_struct
*vma
, unsigned long address
)
3244 struct address_space
*mapping
;
3247 mapping
= vma
->vm_file
->f_mapping
;
3248 idx
= vma_hugecache_offset(h
, vma
, address
);
3250 return find_lock_page(mapping
, idx
);
3254 * Return whether there is a pagecache page to back given address within VMA.
3255 * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page.
3257 static bool hugetlbfs_pagecache_present(struct hstate
*h
,
3258 struct vm_area_struct
*vma
, unsigned long address
)
3260 struct address_space
*mapping
;
3264 mapping
= vma
->vm_file
->f_mapping
;
3265 idx
= vma_hugecache_offset(h
, vma
, address
);
3267 page
= find_get_page(mapping
, idx
);
3270 return page
!= NULL
;
3273 static int hugetlb_no_page(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
3274 struct address_space
*mapping
, pgoff_t idx
,
3275 unsigned long address
, pte_t
*ptep
, unsigned int flags
)
3277 struct hstate
*h
= hstate_vma(vma
);
3278 int ret
= VM_FAULT_SIGBUS
;
3286 * Currently, we are forced to kill the process in the event the
3287 * original mapper has unmapped pages from the child due to a failed
3288 * COW. Warn that such a situation has occurred as it may not be obvious
3290 if (is_vma_resv_set(vma
, HPAGE_RESV_UNMAPPED
)) {
3291 pr_warning("PID %d killed due to inadequate hugepage pool\n",
3297 * Use page lock to guard against racing truncation
3298 * before we get page_table_lock.
3301 page
= find_lock_page(mapping
, idx
);
3303 size
= i_size_read(mapping
->host
) >> huge_page_shift(h
);
3306 page
= alloc_huge_page(vma
, address
, 0);
3308 ret
= PTR_ERR(page
);
3312 ret
= VM_FAULT_SIGBUS
;
3315 clear_huge_page(page
, address
, pages_per_huge_page(h
));
3316 __SetPageUptodate(page
);
3317 set_page_huge_active(page
);
3319 if (vma
->vm_flags
& VM_MAYSHARE
) {
3321 struct inode
*inode
= mapping
->host
;
3323 err
= add_to_page_cache(page
, mapping
, idx
, GFP_KERNEL
);
3330 ClearPagePrivate(page
);
3332 spin_lock(&inode
->i_lock
);
3333 inode
->i_blocks
+= blocks_per_huge_page(h
);
3334 spin_unlock(&inode
->i_lock
);
3337 if (unlikely(anon_vma_prepare(vma
))) {
3339 goto backout_unlocked
;
3345 * If memory error occurs between mmap() and fault, some process
3346 * don't have hwpoisoned swap entry for errored virtual address.
3347 * So we need to block hugepage fault by PG_hwpoison bit check.
3349 if (unlikely(PageHWPoison(page
))) {
3350 ret
= VM_FAULT_HWPOISON
|
3351 VM_FAULT_SET_HINDEX(hstate_index(h
));
3352 goto backout_unlocked
;
3357 * If we are going to COW a private mapping later, we examine the
3358 * pending reservations for this page now. This will ensure that
3359 * any allocations necessary to record that reservation occur outside
3362 if ((flags
& FAULT_FLAG_WRITE
) && !(vma
->vm_flags
& VM_SHARED
)) {
3363 if (vma_needs_reservation(h
, vma
, address
) < 0) {
3365 goto backout_unlocked
;
3367 /* Just decrements count, does not deallocate */
3368 vma_abort_reservation(h
, vma
, address
);
3371 ptl
= huge_pte_lockptr(h
, mm
, ptep
);
3373 size
= i_size_read(mapping
->host
) >> huge_page_shift(h
);
3378 if (!huge_pte_none(huge_ptep_get(ptep
)))
3382 ClearPagePrivate(page
);
3383 hugepage_add_new_anon_rmap(page
, vma
, address
);
3385 page_dup_rmap(page
);
3386 new_pte
= make_huge_pte(vma
, page
, ((vma
->vm_flags
& VM_WRITE
)
3387 && (vma
->vm_flags
& VM_SHARED
)));
3388 set_huge_pte_at(mm
, address
, ptep
, new_pte
);
3390 if ((flags
& FAULT_FLAG_WRITE
) && !(vma
->vm_flags
& VM_SHARED
)) {
3391 /* Optimization, do the COW without a second fault */
3392 ret
= hugetlb_cow(mm
, vma
, address
, ptep
, new_pte
, page
, ptl
);
3409 static u32
fault_mutex_hash(struct hstate
*h
, struct mm_struct
*mm
,
3410 struct vm_area_struct
*vma
,
3411 struct address_space
*mapping
,
3412 pgoff_t idx
, unsigned long address
)
3414 unsigned long key
[2];
3417 if (vma
->vm_flags
& VM_SHARED
) {
3418 key
[0] = (unsigned long) mapping
;
3421 key
[0] = (unsigned long) mm
;
3422 key
[1] = address
>> huge_page_shift(h
);
3425 hash
= jhash2((u32
*)&key
, sizeof(key
)/sizeof(u32
), 0);
3427 return hash
& (num_fault_mutexes
- 1);
3431 * For uniprocesor systems we always use a single mutex, so just
3432 * return 0 and avoid the hashing overhead.
3434 static u32
fault_mutex_hash(struct hstate
*h
, struct mm_struct
*mm
,
3435 struct vm_area_struct
*vma
,
3436 struct address_space
*mapping
,
3437 pgoff_t idx
, unsigned long address
)
3443 int hugetlb_fault(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
3444 unsigned long address
, unsigned int flags
)
3451 struct page
*page
= NULL
;
3452 struct page
*pagecache_page
= NULL
;
3453 struct hstate
*h
= hstate_vma(vma
);
3454 struct address_space
*mapping
;
3455 int need_wait_lock
= 0;
3457 address
&= huge_page_mask(h
);
3459 ptep
= huge_pte_offset(mm
, address
);
3461 entry
= huge_ptep_get(ptep
);
3462 if (unlikely(is_hugetlb_entry_migration(entry
))) {
3463 migration_entry_wait_huge(vma
, mm
, ptep
);
3465 } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry
)))
3466 return VM_FAULT_HWPOISON_LARGE
|
3467 VM_FAULT_SET_HINDEX(hstate_index(h
));
3470 ptep
= huge_pte_alloc(mm
, address
, huge_page_size(h
));
3472 return VM_FAULT_OOM
;
3474 mapping
= vma
->vm_file
->f_mapping
;
3475 idx
= vma_hugecache_offset(h
, vma
, address
);
3478 * Serialize hugepage allocation and instantiation, so that we don't
3479 * get spurious allocation failures if two CPUs race to instantiate
3480 * the same page in the page cache.
3482 hash
= fault_mutex_hash(h
, mm
, vma
, mapping
, idx
, address
);
3483 mutex_lock(&htlb_fault_mutex_table
[hash
]);
3485 entry
= huge_ptep_get(ptep
);
3486 if (huge_pte_none(entry
)) {
3487 ret
= hugetlb_no_page(mm
, vma
, mapping
, idx
, address
, ptep
, flags
);
3494 * entry could be a migration/hwpoison entry at this point, so this
3495 * check prevents the kernel from going below assuming that we have
3496 * a active hugepage in pagecache. This goto expects the 2nd page fault,
3497 * and is_hugetlb_entry_(migration|hwpoisoned) check will properly
3500 if (!pte_present(entry
))
3504 * If we are going to COW the mapping later, we examine the pending
3505 * reservations for this page now. This will ensure that any
3506 * allocations necessary to record that reservation occur outside the
3507 * spinlock. For private mappings, we also lookup the pagecache
3508 * page now as it is used to determine if a reservation has been
3511 if ((flags
& FAULT_FLAG_WRITE
) && !huge_pte_write(entry
)) {
3512 if (vma_needs_reservation(h
, vma
, address
) < 0) {
3516 /* Just decrements count, does not deallocate */
3517 vma_abort_reservation(h
, vma
, address
);
3519 if (!(vma
->vm_flags
& VM_MAYSHARE
))
3520 pagecache_page
= hugetlbfs_pagecache_page(h
,
3524 ptl
= huge_pte_lock(h
, mm
, ptep
);
3526 /* Check for a racing update before calling hugetlb_cow */
3527 if (unlikely(!pte_same(entry
, huge_ptep_get(ptep
))))
3531 * hugetlb_cow() requires page locks of pte_page(entry) and
3532 * pagecache_page, so here we need take the former one
3533 * when page != pagecache_page or !pagecache_page.
3535 page
= pte_page(entry
);
3536 if (page
!= pagecache_page
)
3537 if (!trylock_page(page
)) {
3544 if (flags
& FAULT_FLAG_WRITE
) {
3545 if (!huge_pte_write(entry
)) {
3546 ret
= hugetlb_cow(mm
, vma
, address
, ptep
, entry
,
3547 pagecache_page
, ptl
);
3550 entry
= huge_pte_mkdirty(entry
);
3552 entry
= pte_mkyoung(entry
);
3553 if (huge_ptep_set_access_flags(vma
, address
, ptep
, entry
,
3554 flags
& FAULT_FLAG_WRITE
))
3555 update_mmu_cache(vma
, address
, ptep
);
3557 if (page
!= pagecache_page
)
3563 if (pagecache_page
) {
3564 unlock_page(pagecache_page
);
3565 put_page(pagecache_page
);
3568 mutex_unlock(&htlb_fault_mutex_table
[hash
]);
3570 * Generally it's safe to hold refcount during waiting page lock. But
3571 * here we just wait to defer the next page fault to avoid busy loop and
3572 * the page is not used after unlocked before returning from the current
3573 * page fault. So we are safe from accessing freed page, even if we wait
3574 * here without taking refcount.
3577 wait_on_page_locked(page
);
3581 long follow_hugetlb_page(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
3582 struct page
**pages
, struct vm_area_struct
**vmas
,
3583 unsigned long *position
, unsigned long *nr_pages
,
3584 long i
, unsigned int flags
)
3586 unsigned long pfn_offset
;
3587 unsigned long vaddr
= *position
;
3588 unsigned long remainder
= *nr_pages
;
3589 struct hstate
*h
= hstate_vma(vma
);
3591 while (vaddr
< vma
->vm_end
&& remainder
) {
3593 spinlock_t
*ptl
= NULL
;
3598 * If we have a pending SIGKILL, don't keep faulting pages and
3599 * potentially allocating memory.
3601 if (unlikely(fatal_signal_pending(current
))) {
3607 * Some archs (sparc64, sh*) have multiple pte_ts to
3608 * each hugepage. We have to make sure we get the
3609 * first, for the page indexing below to work.
3611 * Note that page table lock is not held when pte is null.
3613 pte
= huge_pte_offset(mm
, vaddr
& huge_page_mask(h
));
3615 ptl
= huge_pte_lock(h
, mm
, pte
);
3616 absent
= !pte
|| huge_pte_none(huge_ptep_get(pte
));
3619 * When coredumping, it suits get_dump_page if we just return
3620 * an error where there's an empty slot with no huge pagecache
3621 * to back it. This way, we avoid allocating a hugepage, and
3622 * the sparse dumpfile avoids allocating disk blocks, but its
3623 * huge holes still show up with zeroes where they need to be.
3625 if (absent
&& (flags
& FOLL_DUMP
) &&
3626 !hugetlbfs_pagecache_present(h
, vma
, vaddr
)) {
3634 * We need call hugetlb_fault for both hugepages under migration
3635 * (in which case hugetlb_fault waits for the migration,) and
3636 * hwpoisoned hugepages (in which case we need to prevent the
3637 * caller from accessing to them.) In order to do this, we use
3638 * here is_swap_pte instead of is_hugetlb_entry_migration and
3639 * is_hugetlb_entry_hwpoisoned. This is because it simply covers
3640 * both cases, and because we can't follow correct pages
3641 * directly from any kind of swap entries.
3643 if (absent
|| is_swap_pte(huge_ptep_get(pte
)) ||
3644 ((flags
& FOLL_WRITE
) &&
3645 !huge_pte_write(huge_ptep_get(pte
)))) {
3650 ret
= hugetlb_fault(mm
, vma
, vaddr
,
3651 (flags
& FOLL_WRITE
) ? FAULT_FLAG_WRITE
: 0);
3652 if (!(ret
& VM_FAULT_ERROR
))
3659 pfn_offset
= (vaddr
& ~huge_page_mask(h
)) >> PAGE_SHIFT
;
3660 page
= pte_page(huge_ptep_get(pte
));
3663 pages
[i
] = mem_map_offset(page
, pfn_offset
);
3664 get_page_foll(pages
[i
]);
3674 if (vaddr
< vma
->vm_end
&& remainder
&&
3675 pfn_offset
< pages_per_huge_page(h
)) {
3677 * We use pfn_offset to avoid touching the pageframes
3678 * of this compound page.
3684 *nr_pages
= remainder
;
3687 return i
? i
: -EFAULT
;
3690 unsigned long hugetlb_change_protection(struct vm_area_struct
*vma
,
3691 unsigned long address
, unsigned long end
, pgprot_t newprot
)
3693 struct mm_struct
*mm
= vma
->vm_mm
;
3694 unsigned long start
= address
;
3697 struct hstate
*h
= hstate_vma(vma
);
3698 unsigned long pages
= 0;
3700 BUG_ON(address
>= end
);
3701 flush_cache_range(vma
, address
, end
);
3703 mmu_notifier_invalidate_range_start(mm
, start
, end
);
3704 i_mmap_lock_write(vma
->vm_file
->f_mapping
);
3705 for (; address
< end
; address
+= huge_page_size(h
)) {
3707 ptep
= huge_pte_offset(mm
, address
);
3710 ptl
= huge_pte_lock(h
, mm
, ptep
);
3711 if (huge_pmd_unshare(mm
, &address
, ptep
)) {
3716 pte
= huge_ptep_get(ptep
);
3717 if (unlikely(is_hugetlb_entry_hwpoisoned(pte
))) {
3721 if (unlikely(is_hugetlb_entry_migration(pte
))) {
3722 swp_entry_t entry
= pte_to_swp_entry(pte
);
3724 if (is_write_migration_entry(entry
)) {
3727 make_migration_entry_read(&entry
);
3728 newpte
= swp_entry_to_pte(entry
);
3729 set_huge_pte_at(mm
, address
, ptep
, newpte
);
3735 if (!huge_pte_none(pte
)) {
3736 pte
= huge_ptep_get_and_clear(mm
, address
, ptep
);
3737 pte
= pte_mkhuge(huge_pte_modify(pte
, newprot
));
3738 pte
= arch_make_huge_pte(pte
, vma
, NULL
, 0);
3739 set_huge_pte_at(mm
, address
, ptep
, pte
);
3745 * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare
3746 * may have cleared our pud entry and done put_page on the page table:
3747 * once we release i_mmap_rwsem, another task can do the final put_page
3748 * and that page table be reused and filled with junk.
3750 flush_tlb_range(vma
, start
, end
);
3751 mmu_notifier_invalidate_range(mm
, start
, end
);
3752 i_mmap_unlock_write(vma
->vm_file
->f_mapping
);
3753 mmu_notifier_invalidate_range_end(mm
, start
, end
);
3755 return pages
<< h
->order
;
3758 int hugetlb_reserve_pages(struct inode
*inode
,
3760 struct vm_area_struct
*vma
,
3761 vm_flags_t vm_flags
)
3764 struct hstate
*h
= hstate_inode(inode
);
3765 struct hugepage_subpool
*spool
= subpool_inode(inode
);
3766 struct resv_map
*resv_map
;
3770 * Only apply hugepage reservation if asked. At fault time, an
3771 * attempt will be made for VM_NORESERVE to allocate a page
3772 * without using reserves
3774 if (vm_flags
& VM_NORESERVE
)
3778 * Shared mappings base their reservation on the number of pages that
3779 * are already allocated on behalf of the file. Private mappings need
3780 * to reserve the full area even if read-only as mprotect() may be
3781 * called to make the mapping read-write. Assume !vma is a shm mapping
3783 if (!vma
|| vma
->vm_flags
& VM_MAYSHARE
) {
3784 resv_map
= inode_resv_map(inode
);
3786 chg
= region_chg(resv_map
, from
, to
);
3789 resv_map
= resv_map_alloc();
3795 set_vma_resv_map(vma
, resv_map
);
3796 set_vma_resv_flags(vma
, HPAGE_RESV_OWNER
);
3805 * There must be enough pages in the subpool for the mapping. If
3806 * the subpool has a minimum size, there may be some global
3807 * reservations already in place (gbl_reserve).
3809 gbl_reserve
= hugepage_subpool_get_pages(spool
, chg
);
3810 if (gbl_reserve
< 0) {
3816 * Check enough hugepages are available for the reservation.
3817 * Hand the pages back to the subpool if there are not
3819 ret
= hugetlb_acct_memory(h
, gbl_reserve
);
3821 /* put back original number of pages, chg */
3822 (void)hugepage_subpool_put_pages(spool
, chg
);
3827 * Account for the reservations made. Shared mappings record regions
3828 * that have reservations as they are shared by multiple VMAs.
3829 * When the last VMA disappears, the region map says how much
3830 * the reservation was and the page cache tells how much of
3831 * the reservation was consumed. Private mappings are per-VMA and
3832 * only the consumed reservations are tracked. When the VMA
3833 * disappears, the original reservation is the VMA size and the
3834 * consumed reservations are stored in the map. Hence, nothing
3835 * else has to be done for private mappings here
3837 if (!vma
|| vma
->vm_flags
& VM_MAYSHARE
) {
3838 long add
= region_add(resv_map
, from
, to
);
3840 if (unlikely(chg
> add
)) {
3842 * pages in this range were added to the reserve
3843 * map between region_chg and region_add. This
3844 * indicates a race with alloc_huge_page. Adjust
3845 * the subpool and reserve counts modified above
3846 * based on the difference.
3850 rsv_adjust
= hugepage_subpool_put_pages(spool
,
3852 hugetlb_acct_memory(h
, -rsv_adjust
);
3857 if (!vma
|| vma
->vm_flags
& VM_MAYSHARE
)
3858 region_abort(resv_map
, from
, to
);
3859 if (vma
&& is_vma_resv_set(vma
, HPAGE_RESV_OWNER
))
3860 kref_put(&resv_map
->refs
, resv_map_release
);
3864 void hugetlb_unreserve_pages(struct inode
*inode
, long offset
, long freed
)
3866 struct hstate
*h
= hstate_inode(inode
);
3867 struct resv_map
*resv_map
= inode_resv_map(inode
);
3869 struct hugepage_subpool
*spool
= subpool_inode(inode
);
3873 chg
= region_truncate(resv_map
, offset
);
3874 spin_lock(&inode
->i_lock
);
3875 inode
->i_blocks
-= (blocks_per_huge_page(h
) * freed
);
3876 spin_unlock(&inode
->i_lock
);
3879 * If the subpool has a minimum size, the number of global
3880 * reservations to be released may be adjusted.
3882 gbl_reserve
= hugepage_subpool_put_pages(spool
, (chg
- freed
));
3883 hugetlb_acct_memory(h
, -gbl_reserve
);
3886 #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
3887 static unsigned long page_table_shareable(struct vm_area_struct
*svma
,
3888 struct vm_area_struct
*vma
,
3889 unsigned long addr
, pgoff_t idx
)
3891 unsigned long saddr
= ((idx
- svma
->vm_pgoff
) << PAGE_SHIFT
) +
3893 unsigned long sbase
= saddr
& PUD_MASK
;
3894 unsigned long s_end
= sbase
+ PUD_SIZE
;
3896 /* Allow segments to share if only one is marked locked */
3897 unsigned long vm_flags
= vma
->vm_flags
& ~VM_LOCKED
;
3898 unsigned long svm_flags
= svma
->vm_flags
& ~VM_LOCKED
;
3901 * match the virtual addresses, permission and the alignment of the
3904 if (pmd_index(addr
) != pmd_index(saddr
) ||
3905 vm_flags
!= svm_flags
||
3906 sbase
< svma
->vm_start
|| svma
->vm_end
< s_end
)
3912 static bool vma_shareable(struct vm_area_struct
*vma
, unsigned long addr
)
3914 unsigned long base
= addr
& PUD_MASK
;
3915 unsigned long end
= base
+ PUD_SIZE
;
3918 * check on proper vm_flags and page table alignment
3920 if (vma
->vm_flags
& VM_MAYSHARE
&&
3921 vma
->vm_start
<= base
&& end
<= vma
->vm_end
)
3927 * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc()
3928 * and returns the corresponding pte. While this is not necessary for the
3929 * !shared pmd case because we can allocate the pmd later as well, it makes the
3930 * code much cleaner. pmd allocation is essential for the shared case because
3931 * pud has to be populated inside the same i_mmap_rwsem section - otherwise
3932 * racing tasks could either miss the sharing (see huge_pte_offset) or select a
3933 * bad pmd for sharing.
3935 pte_t
*huge_pmd_share(struct mm_struct
*mm
, unsigned long addr
, pud_t
*pud
)
3937 struct vm_area_struct
*vma
= find_vma(mm
, addr
);
3938 struct address_space
*mapping
= vma
->vm_file
->f_mapping
;
3939 pgoff_t idx
= ((addr
- vma
->vm_start
) >> PAGE_SHIFT
) +
3941 struct vm_area_struct
*svma
;
3942 unsigned long saddr
;
3947 if (!vma_shareable(vma
, addr
))
3948 return (pte_t
*)pmd_alloc(mm
, pud
, addr
);
3950 i_mmap_lock_write(mapping
);
3951 vma_interval_tree_foreach(svma
, &mapping
->i_mmap
, idx
, idx
) {
3955 saddr
= page_table_shareable(svma
, vma
, addr
, idx
);
3957 spte
= huge_pte_offset(svma
->vm_mm
, saddr
);
3960 get_page(virt_to_page(spte
));
3969 ptl
= huge_pte_lockptr(hstate_vma(vma
), mm
, spte
);
3971 if (pud_none(*pud
)) {
3972 pud_populate(mm
, pud
,
3973 (pmd_t
*)((unsigned long)spte
& PAGE_MASK
));
3975 put_page(virt_to_page(spte
));
3980 pte
= (pte_t
*)pmd_alloc(mm
, pud
, addr
);
3981 i_mmap_unlock_write(mapping
);
3986 * unmap huge page backed by shared pte.
3988 * Hugetlb pte page is ref counted at the time of mapping. If pte is shared
3989 * indicated by page_count > 1, unmap is achieved by clearing pud and
3990 * decrementing the ref count. If count == 1, the pte page is not shared.
3992 * called with page table lock held.
3994 * returns: 1 successfully unmapped a shared pte page
3995 * 0 the underlying pte page is not shared, or it is the last user
3997 int huge_pmd_unshare(struct mm_struct
*mm
, unsigned long *addr
, pte_t
*ptep
)
3999 pgd_t
*pgd
= pgd_offset(mm
, *addr
);
4000 pud_t
*pud
= pud_offset(pgd
, *addr
);
4002 BUG_ON(page_count(virt_to_page(ptep
)) == 0);
4003 if (page_count(virt_to_page(ptep
)) == 1)
4007 put_page(virt_to_page(ptep
));
4009 *addr
= ALIGN(*addr
, HPAGE_SIZE
* PTRS_PER_PTE
) - HPAGE_SIZE
;
4012 #define want_pmd_share() (1)
4013 #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
4014 pte_t
*huge_pmd_share(struct mm_struct
*mm
, unsigned long addr
, pud_t
*pud
)
4019 int huge_pmd_unshare(struct mm_struct
*mm
, unsigned long *addr
, pte_t
*ptep
)
4023 #define want_pmd_share() (0)
4024 #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
4026 #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
4027 pte_t
*huge_pte_alloc(struct mm_struct
*mm
,
4028 unsigned long addr
, unsigned long sz
)
4034 pgd
= pgd_offset(mm
, addr
);
4035 pud
= pud_alloc(mm
, pgd
, addr
);
4037 if (sz
== PUD_SIZE
) {
4040 BUG_ON(sz
!= PMD_SIZE
);
4041 if (want_pmd_share() && pud_none(*pud
))
4042 pte
= huge_pmd_share(mm
, addr
, pud
);
4044 pte
= (pte_t
*)pmd_alloc(mm
, pud
, addr
);
4047 BUG_ON(pte
&& !pte_none(*pte
) && !pte_huge(*pte
));
4052 pte_t
*huge_pte_offset(struct mm_struct
*mm
, unsigned long addr
)
4058 pgd
= pgd_offset(mm
, addr
);
4059 if (pgd_present(*pgd
)) {
4060 pud
= pud_offset(pgd
, addr
);
4061 if (pud_present(*pud
)) {
4063 return (pte_t
*)pud
;
4064 pmd
= pmd_offset(pud
, addr
);
4067 return (pte_t
*) pmd
;
4070 #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
4073 * These functions are overwritable if your architecture needs its own
4076 struct page
* __weak
4077 follow_huge_addr(struct mm_struct
*mm
, unsigned long address
,
4080 return ERR_PTR(-EINVAL
);
4083 struct page
* __weak
4084 follow_huge_pmd(struct mm_struct
*mm
, unsigned long address
,
4085 pmd_t
*pmd
, int flags
)
4087 struct page
*page
= NULL
;
4090 ptl
= pmd_lockptr(mm
, pmd
);
4093 * make sure that the address range covered by this pmd is not
4094 * unmapped from other threads.
4096 if (!pmd_huge(*pmd
))
4098 if (pmd_present(*pmd
)) {
4099 page
= pmd_page(*pmd
) + ((address
& ~PMD_MASK
) >> PAGE_SHIFT
);
4100 if (flags
& FOLL_GET
)
4103 if (is_hugetlb_entry_migration(huge_ptep_get((pte_t
*)pmd
))) {
4105 __migration_entry_wait(mm
, (pte_t
*)pmd
, ptl
);
4109 * hwpoisoned entry is treated as no_page_table in
4110 * follow_page_mask().
4118 struct page
* __weak
4119 follow_huge_pud(struct mm_struct
*mm
, unsigned long address
,
4120 pud_t
*pud
, int flags
)
4122 if (flags
& FOLL_GET
)
4125 return pte_page(*(pte_t
*)pud
) + ((address
& ~PUD_MASK
) >> PAGE_SHIFT
);
4128 #ifdef CONFIG_MEMORY_FAILURE
4131 * This function is called from memory failure code.
4132 * Assume the caller holds page lock of the head page.
4134 int dequeue_hwpoisoned_huge_page(struct page
*hpage
)
4136 struct hstate
*h
= page_hstate(hpage
);
4137 int nid
= page_to_nid(hpage
);
4140 spin_lock(&hugetlb_lock
);
4142 * Just checking !page_huge_active is not enough, because that could be
4143 * an isolated/hwpoisoned hugepage (which have >0 refcount).
4145 if (!page_huge_active(hpage
) && !page_count(hpage
)) {
4147 * Hwpoisoned hugepage isn't linked to activelist or freelist,
4148 * but dangling hpage->lru can trigger list-debug warnings
4149 * (this happens when we call unpoison_memory() on it),
4150 * so let it point to itself with list_del_init().
4152 list_del_init(&hpage
->lru
);
4153 set_page_refcounted(hpage
);
4154 h
->free_huge_pages
--;
4155 h
->free_huge_pages_node
[nid
]--;
4158 spin_unlock(&hugetlb_lock
);
4163 bool isolate_huge_page(struct page
*page
, struct list_head
*list
)
4167 VM_BUG_ON_PAGE(!PageHead(page
), page
);
4168 spin_lock(&hugetlb_lock
);
4169 if (!page_huge_active(page
) || !get_page_unless_zero(page
)) {
4173 clear_page_huge_active(page
);
4174 list_move_tail(&page
->lru
, list
);
4176 spin_unlock(&hugetlb_lock
);
4180 void putback_active_hugepage(struct page
*page
)
4182 VM_BUG_ON_PAGE(!PageHead(page
), page
);
4183 spin_lock(&hugetlb_lock
);
4184 set_page_huge_active(page
);
4185 list_move_tail(&page
->lru
, &(page_hstate(page
))->hugepage_activelist
);
4186 spin_unlock(&hugetlb_lock
);