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. Existing regions will be expanded to accommodate the
244 * specified range. We know only existing regions need to be
245 * expanded, because region_add is only called after region_chg
246 * with the same range. If a new file_region structure must
247 * be allocated, it is done in region_chg.
249 * Return the number of new huge pages added to the map. This
250 * number is greater than or equal to zero.
252 static long region_add(struct resv_map
*resv
, long f
, long t
)
254 struct list_head
*head
= &resv
->regions
;
255 struct file_region
*rg
, *nrg
, *trg
;
258 spin_lock(&resv
->lock
);
259 /* Locate the region we are either in or before. */
260 list_for_each_entry(rg
, head
, link
)
264 /* Round our left edge to the current segment if it encloses us. */
268 /* Check for and consume any regions we now overlap with. */
270 list_for_each_entry_safe(rg
, trg
, rg
->link
.prev
, link
) {
271 if (&rg
->link
== head
)
276 /* If this area reaches higher then extend our area to
277 * include it completely. If this is not the first area
278 * which we intend to reuse, free it. */
282 /* Decrement return value by the deleted range.
283 * Another range will span this area so that by
284 * end of routine add will be >= zero
286 add
-= (rg
->to
- rg
->from
);
292 add
+= (nrg
->from
- f
); /* Added to beginning of region */
294 add
+= t
- nrg
->to
; /* Added to end of region */
297 spin_unlock(&resv
->lock
);
303 * Examine the existing reserve map and determine how many
304 * huge pages in the specified range [f, t) are NOT currently
305 * represented. This routine is called before a subsequent
306 * call to region_add that will actually modify the reserve
307 * map to add the specified range [f, t). region_chg does
308 * not change the number of huge pages represented by the
309 * map. However, if the existing regions in the map can not
310 * be expanded to represent the new range, a new file_region
311 * structure is added to the map as a placeholder. This is
312 * so that the subsequent region_add call will have all the
313 * regions it needs and will not fail.
315 * Returns the number of huge pages that need to be added
316 * to the existing reservation map for the range [f, t).
317 * This number is greater or equal to zero. -ENOMEM is
318 * returned if a new file_region structure is needed and can
321 static long region_chg(struct resv_map
*resv
, long f
, long t
)
323 struct list_head
*head
= &resv
->regions
;
324 struct file_region
*rg
, *nrg
= NULL
;
328 spin_lock(&resv
->lock
);
329 /* Locate the region we are before or in. */
330 list_for_each_entry(rg
, head
, link
)
334 /* If we are below the current region then a new region is required.
335 * Subtle, allocate a new region at the position but make it zero
336 * size such that we can guarantee to record the reservation. */
337 if (&rg
->link
== head
|| t
< rg
->from
) {
339 spin_unlock(&resv
->lock
);
340 nrg
= kmalloc(sizeof(*nrg
), GFP_KERNEL
);
346 INIT_LIST_HEAD(&nrg
->link
);
350 list_add(&nrg
->link
, rg
->link
.prev
);
355 /* Round our left edge to the current segment if it encloses us. */
360 /* Check for and consume any regions we now overlap with. */
361 list_for_each_entry(rg
, rg
->link
.prev
, link
) {
362 if (&rg
->link
== head
)
367 /* We overlap with this area, if it extends further than
368 * us then we must extend ourselves. Account for its
369 * existing reservation. */
374 chg
-= rg
->to
- rg
->from
;
378 spin_unlock(&resv
->lock
);
379 /* We already know we raced and no longer need the new region */
383 spin_unlock(&resv
->lock
);
388 * Truncate the reserve map at index 'end'. Modify/truncate any
389 * region which contains end. Delete any regions past end.
390 * Return the number of huge pages removed from the map.
392 static long region_truncate(struct resv_map
*resv
, long end
)
394 struct list_head
*head
= &resv
->regions
;
395 struct file_region
*rg
, *trg
;
398 spin_lock(&resv
->lock
);
399 /* Locate the region we are either in or before. */
400 list_for_each_entry(rg
, head
, link
)
403 if (&rg
->link
== head
)
406 /* If we are in the middle of a region then adjust it. */
407 if (end
> rg
->from
) {
410 rg
= list_entry(rg
->link
.next
, typeof(*rg
), link
);
413 /* Drop any remaining regions. */
414 list_for_each_entry_safe(rg
, trg
, rg
->link
.prev
, link
) {
415 if (&rg
->link
== head
)
417 chg
+= rg
->to
- rg
->from
;
423 spin_unlock(&resv
->lock
);
428 * Count and return the number of huge pages in the reserve map
429 * that intersect with the range [f, t).
431 static long region_count(struct resv_map
*resv
, long f
, long t
)
433 struct list_head
*head
= &resv
->regions
;
434 struct file_region
*rg
;
437 spin_lock(&resv
->lock
);
438 /* Locate each segment we overlap with, and count that overlap. */
439 list_for_each_entry(rg
, head
, link
) {
448 seg_from
= max(rg
->from
, f
);
449 seg_to
= min(rg
->to
, t
);
451 chg
+= seg_to
- seg_from
;
453 spin_unlock(&resv
->lock
);
459 * Convert the address within this vma to the page offset within
460 * the mapping, in pagecache page units; huge pages here.
462 static pgoff_t
vma_hugecache_offset(struct hstate
*h
,
463 struct vm_area_struct
*vma
, unsigned long address
)
465 return ((address
- vma
->vm_start
) >> huge_page_shift(h
)) +
466 (vma
->vm_pgoff
>> huge_page_order(h
));
469 pgoff_t
linear_hugepage_index(struct vm_area_struct
*vma
,
470 unsigned long address
)
472 return vma_hugecache_offset(hstate_vma(vma
), vma
, address
);
476 * Return the size of the pages allocated when backing a VMA. In the majority
477 * cases this will be same size as used by the page table entries.
479 unsigned long vma_kernel_pagesize(struct vm_area_struct
*vma
)
481 struct hstate
*hstate
;
483 if (!is_vm_hugetlb_page(vma
))
486 hstate
= hstate_vma(vma
);
488 return 1UL << huge_page_shift(hstate
);
490 EXPORT_SYMBOL_GPL(vma_kernel_pagesize
);
493 * Return the page size being used by the MMU to back a VMA. In the majority
494 * of cases, the page size used by the kernel matches the MMU size. On
495 * architectures where it differs, an architecture-specific version of this
496 * function is required.
498 #ifndef vma_mmu_pagesize
499 unsigned long vma_mmu_pagesize(struct vm_area_struct
*vma
)
501 return vma_kernel_pagesize(vma
);
506 * Flags for MAP_PRIVATE reservations. These are stored in the bottom
507 * bits of the reservation map pointer, which are always clear due to
510 #define HPAGE_RESV_OWNER (1UL << 0)
511 #define HPAGE_RESV_UNMAPPED (1UL << 1)
512 #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED)
515 * These helpers are used to track how many pages are reserved for
516 * faults in a MAP_PRIVATE mapping. Only the process that called mmap()
517 * is guaranteed to have their future faults succeed.
519 * With the exception of reset_vma_resv_huge_pages() which is called at fork(),
520 * the reserve counters are updated with the hugetlb_lock held. It is safe
521 * to reset the VMA at fork() time as it is not in use yet and there is no
522 * chance of the global counters getting corrupted as a result of the values.
524 * The private mapping reservation is represented in a subtly different
525 * manner to a shared mapping. A shared mapping has a region map associated
526 * with the underlying file, this region map represents the backing file
527 * pages which have ever had a reservation assigned which this persists even
528 * after the page is instantiated. A private mapping has a region map
529 * associated with the original mmap which is attached to all VMAs which
530 * reference it, this region map represents those offsets which have consumed
531 * reservation ie. where pages have been instantiated.
533 static unsigned long get_vma_private_data(struct vm_area_struct
*vma
)
535 return (unsigned long)vma
->vm_private_data
;
538 static void set_vma_private_data(struct vm_area_struct
*vma
,
541 vma
->vm_private_data
= (void *)value
;
544 struct resv_map
*resv_map_alloc(void)
546 struct resv_map
*resv_map
= kmalloc(sizeof(*resv_map
), GFP_KERNEL
);
550 kref_init(&resv_map
->refs
);
551 spin_lock_init(&resv_map
->lock
);
552 INIT_LIST_HEAD(&resv_map
->regions
);
557 void resv_map_release(struct kref
*ref
)
559 struct resv_map
*resv_map
= container_of(ref
, struct resv_map
, refs
);
561 /* Clear out any active regions before we release the map. */
562 region_truncate(resv_map
, 0);
566 static inline struct resv_map
*inode_resv_map(struct inode
*inode
)
568 return inode
->i_mapping
->private_data
;
571 static struct resv_map
*vma_resv_map(struct vm_area_struct
*vma
)
573 VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma
), vma
);
574 if (vma
->vm_flags
& VM_MAYSHARE
) {
575 struct address_space
*mapping
= vma
->vm_file
->f_mapping
;
576 struct inode
*inode
= mapping
->host
;
578 return inode_resv_map(inode
);
581 return (struct resv_map
*)(get_vma_private_data(vma
) &
586 static void set_vma_resv_map(struct vm_area_struct
*vma
, struct resv_map
*map
)
588 VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma
), vma
);
589 VM_BUG_ON_VMA(vma
->vm_flags
& VM_MAYSHARE
, vma
);
591 set_vma_private_data(vma
, (get_vma_private_data(vma
) &
592 HPAGE_RESV_MASK
) | (unsigned long)map
);
595 static void set_vma_resv_flags(struct vm_area_struct
*vma
, unsigned long flags
)
597 VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma
), vma
);
598 VM_BUG_ON_VMA(vma
->vm_flags
& VM_MAYSHARE
, vma
);
600 set_vma_private_data(vma
, get_vma_private_data(vma
) | flags
);
603 static int is_vma_resv_set(struct vm_area_struct
*vma
, unsigned long flag
)
605 VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma
), vma
);
607 return (get_vma_private_data(vma
) & flag
) != 0;
610 /* Reset counters to 0 and clear all HPAGE_RESV_* flags */
611 void reset_vma_resv_huge_pages(struct vm_area_struct
*vma
)
613 VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma
), vma
);
614 if (!(vma
->vm_flags
& VM_MAYSHARE
))
615 vma
->vm_private_data
= (void *)0;
618 /* Returns true if the VMA has associated reserve pages */
619 static int vma_has_reserves(struct vm_area_struct
*vma
, long chg
)
621 if (vma
->vm_flags
& VM_NORESERVE
) {
623 * This address is already reserved by other process(chg == 0),
624 * so, we should decrement reserved count. Without decrementing,
625 * reserve count remains after releasing inode, because this
626 * allocated page will go into page cache and is regarded as
627 * coming from reserved pool in releasing step. Currently, we
628 * don't have any other solution to deal with this situation
629 * properly, so add work-around here.
631 if (vma
->vm_flags
& VM_MAYSHARE
&& chg
== 0)
637 /* Shared mappings always use reserves */
638 if (vma
->vm_flags
& VM_MAYSHARE
)
642 * Only the process that called mmap() has reserves for
645 if (is_vma_resv_set(vma
, HPAGE_RESV_OWNER
))
651 static void enqueue_huge_page(struct hstate
*h
, struct page
*page
)
653 int nid
= page_to_nid(page
);
654 list_move(&page
->lru
, &h
->hugepage_freelists
[nid
]);
655 h
->free_huge_pages
++;
656 h
->free_huge_pages_node
[nid
]++;
659 static struct page
*dequeue_huge_page_node(struct hstate
*h
, int nid
)
663 list_for_each_entry(page
, &h
->hugepage_freelists
[nid
], lru
)
664 if (!is_migrate_isolate_page(page
))
667 * if 'non-isolated free hugepage' not found on the list,
668 * the allocation fails.
670 if (&h
->hugepage_freelists
[nid
] == &page
->lru
)
672 list_move(&page
->lru
, &h
->hugepage_activelist
);
673 set_page_refcounted(page
);
674 h
->free_huge_pages
--;
675 h
->free_huge_pages_node
[nid
]--;
679 /* Movability of hugepages depends on migration support. */
680 static inline gfp_t
htlb_alloc_mask(struct hstate
*h
)
682 if (hugepages_treat_as_movable
|| hugepage_migration_supported(h
))
683 return GFP_HIGHUSER_MOVABLE
;
688 static struct page
*dequeue_huge_page_vma(struct hstate
*h
,
689 struct vm_area_struct
*vma
,
690 unsigned long address
, int avoid_reserve
,
693 struct page
*page
= NULL
;
694 struct mempolicy
*mpol
;
695 nodemask_t
*nodemask
;
696 struct zonelist
*zonelist
;
699 unsigned int cpuset_mems_cookie
;
702 * A child process with MAP_PRIVATE mappings created by their parent
703 * have no page reserves. This check ensures that reservations are
704 * not "stolen". The child may still get SIGKILLed
706 if (!vma_has_reserves(vma
, chg
) &&
707 h
->free_huge_pages
- h
->resv_huge_pages
== 0)
710 /* If reserves cannot be used, ensure enough pages are in the pool */
711 if (avoid_reserve
&& h
->free_huge_pages
- h
->resv_huge_pages
== 0)
715 cpuset_mems_cookie
= read_mems_allowed_begin();
716 zonelist
= huge_zonelist(vma
, address
,
717 htlb_alloc_mask(h
), &mpol
, &nodemask
);
719 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
720 MAX_NR_ZONES
- 1, nodemask
) {
721 if (cpuset_zone_allowed(zone
, htlb_alloc_mask(h
))) {
722 page
= dequeue_huge_page_node(h
, zone_to_nid(zone
));
726 if (!vma_has_reserves(vma
, chg
))
729 SetPagePrivate(page
);
730 h
->resv_huge_pages
--;
737 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
746 * common helper functions for hstate_next_node_to_{alloc|free}.
747 * We may have allocated or freed a huge page based on a different
748 * nodes_allowed previously, so h->next_node_to_{alloc|free} might
749 * be outside of *nodes_allowed. Ensure that we use an allowed
750 * node for alloc or free.
752 static int next_node_allowed(int nid
, nodemask_t
*nodes_allowed
)
754 nid
= next_node(nid
, *nodes_allowed
);
755 if (nid
== MAX_NUMNODES
)
756 nid
= first_node(*nodes_allowed
);
757 VM_BUG_ON(nid
>= MAX_NUMNODES
);
762 static int get_valid_node_allowed(int nid
, nodemask_t
*nodes_allowed
)
764 if (!node_isset(nid
, *nodes_allowed
))
765 nid
= next_node_allowed(nid
, nodes_allowed
);
770 * returns the previously saved node ["this node"] from which to
771 * allocate a persistent huge page for the pool and advance the
772 * next node from which to allocate, handling wrap at end of node
775 static int hstate_next_node_to_alloc(struct hstate
*h
,
776 nodemask_t
*nodes_allowed
)
780 VM_BUG_ON(!nodes_allowed
);
782 nid
= get_valid_node_allowed(h
->next_nid_to_alloc
, nodes_allowed
);
783 h
->next_nid_to_alloc
= next_node_allowed(nid
, nodes_allowed
);
789 * helper for free_pool_huge_page() - return the previously saved
790 * node ["this node"] from which to free a huge page. Advance the
791 * next node id whether or not we find a free huge page to free so
792 * that the next attempt to free addresses the next node.
794 static int hstate_next_node_to_free(struct hstate
*h
, nodemask_t
*nodes_allowed
)
798 VM_BUG_ON(!nodes_allowed
);
800 nid
= get_valid_node_allowed(h
->next_nid_to_free
, nodes_allowed
);
801 h
->next_nid_to_free
= next_node_allowed(nid
, nodes_allowed
);
806 #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \
807 for (nr_nodes = nodes_weight(*mask); \
809 ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \
812 #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \
813 for (nr_nodes = nodes_weight(*mask); \
815 ((node = hstate_next_node_to_free(hs, mask)) || 1); \
818 #if defined(CONFIG_CMA) && defined(CONFIG_X86_64)
819 static void destroy_compound_gigantic_page(struct page
*page
,
823 int nr_pages
= 1 << order
;
824 struct page
*p
= page
+ 1;
826 for (i
= 1; i
< nr_pages
; i
++, p
= mem_map_next(p
, page
, i
)) {
828 set_page_refcounted(p
);
829 p
->first_page
= NULL
;
832 set_compound_order(page
, 0);
833 __ClearPageHead(page
);
836 static void free_gigantic_page(struct page
*page
, unsigned order
)
838 free_contig_range(page_to_pfn(page
), 1 << order
);
841 static int __alloc_gigantic_page(unsigned long start_pfn
,
842 unsigned long nr_pages
)
844 unsigned long end_pfn
= start_pfn
+ nr_pages
;
845 return alloc_contig_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
);
848 static bool pfn_range_valid_gigantic(unsigned long start_pfn
,
849 unsigned long nr_pages
)
851 unsigned long i
, end_pfn
= start_pfn
+ nr_pages
;
854 for (i
= start_pfn
; i
< end_pfn
; i
++) {
858 page
= pfn_to_page(i
);
860 if (PageReserved(page
))
863 if (page_count(page
) > 0)
873 static bool zone_spans_last_pfn(const struct zone
*zone
,
874 unsigned long start_pfn
, unsigned long nr_pages
)
876 unsigned long last_pfn
= start_pfn
+ nr_pages
- 1;
877 return zone_spans_pfn(zone
, last_pfn
);
880 static struct page
*alloc_gigantic_page(int nid
, unsigned order
)
882 unsigned long nr_pages
= 1 << order
;
883 unsigned long ret
, pfn
, flags
;
886 z
= NODE_DATA(nid
)->node_zones
;
887 for (; z
- NODE_DATA(nid
)->node_zones
< MAX_NR_ZONES
; z
++) {
888 spin_lock_irqsave(&z
->lock
, flags
);
890 pfn
= ALIGN(z
->zone_start_pfn
, nr_pages
);
891 while (zone_spans_last_pfn(z
, pfn
, nr_pages
)) {
892 if (pfn_range_valid_gigantic(pfn
, nr_pages
)) {
894 * We release the zone lock here because
895 * alloc_contig_range() will also lock the zone
896 * at some point. If there's an allocation
897 * spinning on this lock, it may win the race
898 * and cause alloc_contig_range() to fail...
900 spin_unlock_irqrestore(&z
->lock
, flags
);
901 ret
= __alloc_gigantic_page(pfn
, nr_pages
);
903 return pfn_to_page(pfn
);
904 spin_lock_irqsave(&z
->lock
, flags
);
909 spin_unlock_irqrestore(&z
->lock
, flags
);
915 static void prep_new_huge_page(struct hstate
*h
, struct page
*page
, int nid
);
916 static void prep_compound_gigantic_page(struct page
*page
, unsigned long order
);
918 static struct page
*alloc_fresh_gigantic_page_node(struct hstate
*h
, int nid
)
922 page
= alloc_gigantic_page(nid
, huge_page_order(h
));
924 prep_compound_gigantic_page(page
, huge_page_order(h
));
925 prep_new_huge_page(h
, page
, nid
);
931 static int alloc_fresh_gigantic_page(struct hstate
*h
,
932 nodemask_t
*nodes_allowed
)
934 struct page
*page
= NULL
;
937 for_each_node_mask_to_alloc(h
, nr_nodes
, node
, nodes_allowed
) {
938 page
= alloc_fresh_gigantic_page_node(h
, node
);
946 static inline bool gigantic_page_supported(void) { return true; }
948 static inline bool gigantic_page_supported(void) { return false; }
949 static inline void free_gigantic_page(struct page
*page
, unsigned order
) { }
950 static inline void destroy_compound_gigantic_page(struct page
*page
,
951 unsigned long order
) { }
952 static inline int alloc_fresh_gigantic_page(struct hstate
*h
,
953 nodemask_t
*nodes_allowed
) { return 0; }
956 static void update_and_free_page(struct hstate
*h
, struct page
*page
)
960 if (hstate_is_gigantic(h
) && !gigantic_page_supported())
964 h
->nr_huge_pages_node
[page_to_nid(page
)]--;
965 for (i
= 0; i
< pages_per_huge_page(h
); i
++) {
966 page
[i
].flags
&= ~(1 << PG_locked
| 1 << PG_error
|
967 1 << PG_referenced
| 1 << PG_dirty
|
968 1 << PG_active
| 1 << PG_private
|
971 VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page
), page
);
972 set_compound_page_dtor(page
, NULL
);
973 set_page_refcounted(page
);
974 if (hstate_is_gigantic(h
)) {
975 destroy_compound_gigantic_page(page
, huge_page_order(h
));
976 free_gigantic_page(page
, huge_page_order(h
));
978 arch_release_hugepage(page
);
979 __free_pages(page
, huge_page_order(h
));
983 struct hstate
*size_to_hstate(unsigned long size
)
988 if (huge_page_size(h
) == size
)
995 * Test to determine whether the hugepage is "active/in-use" (i.e. being linked
996 * to hstate->hugepage_activelist.)
998 * This function can be called for tail pages, but never returns true for them.
1000 bool page_huge_active(struct page
*page
)
1002 VM_BUG_ON_PAGE(!PageHuge(page
), page
);
1003 return PageHead(page
) && PagePrivate(&page
[1]);
1006 /* never called for tail page */
1007 static void set_page_huge_active(struct page
*page
)
1009 VM_BUG_ON_PAGE(!PageHeadHuge(page
), page
);
1010 SetPagePrivate(&page
[1]);
1013 static void clear_page_huge_active(struct page
*page
)
1015 VM_BUG_ON_PAGE(!PageHeadHuge(page
), page
);
1016 ClearPagePrivate(&page
[1]);
1019 void free_huge_page(struct page
*page
)
1022 * Can't pass hstate in here because it is called from the
1023 * compound page destructor.
1025 struct hstate
*h
= page_hstate(page
);
1026 int nid
= page_to_nid(page
);
1027 struct hugepage_subpool
*spool
=
1028 (struct hugepage_subpool
*)page_private(page
);
1029 bool restore_reserve
;
1031 set_page_private(page
, 0);
1032 page
->mapping
= NULL
;
1033 BUG_ON(page_count(page
));
1034 BUG_ON(page_mapcount(page
));
1035 restore_reserve
= PagePrivate(page
);
1036 ClearPagePrivate(page
);
1039 * A return code of zero implies that the subpool will be under its
1040 * minimum size if the reservation is not restored after page is free.
1041 * Therefore, force restore_reserve operation.
1043 if (hugepage_subpool_put_pages(spool
, 1) == 0)
1044 restore_reserve
= true;
1046 spin_lock(&hugetlb_lock
);
1047 clear_page_huge_active(page
);
1048 hugetlb_cgroup_uncharge_page(hstate_index(h
),
1049 pages_per_huge_page(h
), page
);
1050 if (restore_reserve
)
1051 h
->resv_huge_pages
++;
1053 if (h
->surplus_huge_pages_node
[nid
]) {
1054 /* remove the page from active list */
1055 list_del(&page
->lru
);
1056 update_and_free_page(h
, page
);
1057 h
->surplus_huge_pages
--;
1058 h
->surplus_huge_pages_node
[nid
]--;
1060 arch_clear_hugepage_flags(page
);
1061 enqueue_huge_page(h
, page
);
1063 spin_unlock(&hugetlb_lock
);
1066 static void prep_new_huge_page(struct hstate
*h
, struct page
*page
, int nid
)
1068 INIT_LIST_HEAD(&page
->lru
);
1069 set_compound_page_dtor(page
, free_huge_page
);
1070 spin_lock(&hugetlb_lock
);
1071 set_hugetlb_cgroup(page
, NULL
);
1073 h
->nr_huge_pages_node
[nid
]++;
1074 spin_unlock(&hugetlb_lock
);
1075 put_page(page
); /* free it into the hugepage allocator */
1078 static void prep_compound_gigantic_page(struct page
*page
, unsigned long order
)
1081 int nr_pages
= 1 << order
;
1082 struct page
*p
= page
+ 1;
1084 /* we rely on prep_new_huge_page to set the destructor */
1085 set_compound_order(page
, order
);
1086 __SetPageHead(page
);
1087 __ClearPageReserved(page
);
1088 for (i
= 1; i
< nr_pages
; i
++, p
= mem_map_next(p
, page
, i
)) {
1090 * For gigantic hugepages allocated through bootmem at
1091 * boot, it's safer to be consistent with the not-gigantic
1092 * hugepages and clear the PG_reserved bit from all tail pages
1093 * too. Otherwse drivers using get_user_pages() to access tail
1094 * pages may get the reference counting wrong if they see
1095 * PG_reserved set on a tail page (despite the head page not
1096 * having PG_reserved set). Enforcing this consistency between
1097 * head and tail pages allows drivers to optimize away a check
1098 * on the head page when they need know if put_page() is needed
1099 * after get_user_pages().
1101 __ClearPageReserved(p
);
1102 set_page_count(p
, 0);
1103 p
->first_page
= page
;
1104 /* Make sure p->first_page is always valid for PageTail() */
1111 * PageHuge() only returns true for hugetlbfs pages, but not for normal or
1112 * transparent huge pages. See the PageTransHuge() documentation for more
1115 int PageHuge(struct page
*page
)
1117 if (!PageCompound(page
))
1120 page
= compound_head(page
);
1121 return get_compound_page_dtor(page
) == free_huge_page
;
1123 EXPORT_SYMBOL_GPL(PageHuge
);
1126 * PageHeadHuge() only returns true for hugetlbfs head page, but not for
1127 * normal or transparent huge pages.
1129 int PageHeadHuge(struct page
*page_head
)
1131 if (!PageHead(page_head
))
1134 return get_compound_page_dtor(page_head
) == free_huge_page
;
1137 pgoff_t
__basepage_index(struct page
*page
)
1139 struct page
*page_head
= compound_head(page
);
1140 pgoff_t index
= page_index(page_head
);
1141 unsigned long compound_idx
;
1143 if (!PageHuge(page_head
))
1144 return page_index(page
);
1146 if (compound_order(page_head
) >= MAX_ORDER
)
1147 compound_idx
= page_to_pfn(page
) - page_to_pfn(page_head
);
1149 compound_idx
= page
- page_head
;
1151 return (index
<< compound_order(page_head
)) + compound_idx
;
1154 static struct page
*alloc_fresh_huge_page_node(struct hstate
*h
, int nid
)
1158 page
= alloc_pages_exact_node(nid
,
1159 htlb_alloc_mask(h
)|__GFP_COMP
|__GFP_THISNODE
|
1160 __GFP_REPEAT
|__GFP_NOWARN
,
1161 huge_page_order(h
));
1163 if (arch_prepare_hugepage(page
)) {
1164 __free_pages(page
, huge_page_order(h
));
1167 prep_new_huge_page(h
, page
, nid
);
1173 static int alloc_fresh_huge_page(struct hstate
*h
, nodemask_t
*nodes_allowed
)
1179 for_each_node_mask_to_alloc(h
, nr_nodes
, node
, nodes_allowed
) {
1180 page
= alloc_fresh_huge_page_node(h
, node
);
1188 count_vm_event(HTLB_BUDDY_PGALLOC
);
1190 count_vm_event(HTLB_BUDDY_PGALLOC_FAIL
);
1196 * Free huge page from pool from next node to free.
1197 * Attempt to keep persistent huge pages more or less
1198 * balanced over allowed nodes.
1199 * Called with hugetlb_lock locked.
1201 static int free_pool_huge_page(struct hstate
*h
, nodemask_t
*nodes_allowed
,
1207 for_each_node_mask_to_free(h
, nr_nodes
, node
, nodes_allowed
) {
1209 * If we're returning unused surplus pages, only examine
1210 * nodes with surplus pages.
1212 if ((!acct_surplus
|| h
->surplus_huge_pages_node
[node
]) &&
1213 !list_empty(&h
->hugepage_freelists
[node
])) {
1215 list_entry(h
->hugepage_freelists
[node
].next
,
1217 list_del(&page
->lru
);
1218 h
->free_huge_pages
--;
1219 h
->free_huge_pages_node
[node
]--;
1221 h
->surplus_huge_pages
--;
1222 h
->surplus_huge_pages_node
[node
]--;
1224 update_and_free_page(h
, page
);
1234 * Dissolve a given free hugepage into free buddy pages. This function does
1235 * nothing for in-use (including surplus) hugepages.
1237 static void dissolve_free_huge_page(struct page
*page
)
1239 spin_lock(&hugetlb_lock
);
1240 if (PageHuge(page
) && !page_count(page
)) {
1241 struct hstate
*h
= page_hstate(page
);
1242 int nid
= page_to_nid(page
);
1243 list_del(&page
->lru
);
1244 h
->free_huge_pages
--;
1245 h
->free_huge_pages_node
[nid
]--;
1246 update_and_free_page(h
, page
);
1248 spin_unlock(&hugetlb_lock
);
1252 * Dissolve free hugepages in a given pfn range. Used by memory hotplug to
1253 * make specified memory blocks removable from the system.
1254 * Note that start_pfn should aligned with (minimum) hugepage size.
1256 void dissolve_free_huge_pages(unsigned long start_pfn
, unsigned long end_pfn
)
1260 if (!hugepages_supported())
1263 VM_BUG_ON(!IS_ALIGNED(start_pfn
, 1 << minimum_order
));
1264 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= 1 << minimum_order
)
1265 dissolve_free_huge_page(pfn_to_page(pfn
));
1268 static struct page
*alloc_buddy_huge_page(struct hstate
*h
, int nid
)
1273 if (hstate_is_gigantic(h
))
1277 * Assume we will successfully allocate the surplus page to
1278 * prevent racing processes from causing the surplus to exceed
1281 * This however introduces a different race, where a process B
1282 * tries to grow the static hugepage pool while alloc_pages() is
1283 * called by process A. B will only examine the per-node
1284 * counters in determining if surplus huge pages can be
1285 * converted to normal huge pages in adjust_pool_surplus(). A
1286 * won't be able to increment the per-node counter, until the
1287 * lock is dropped by B, but B doesn't drop hugetlb_lock until
1288 * no more huge pages can be converted from surplus to normal
1289 * state (and doesn't try to convert again). Thus, we have a
1290 * case where a surplus huge page exists, the pool is grown, and
1291 * the surplus huge page still exists after, even though it
1292 * should just have been converted to a normal huge page. This
1293 * does not leak memory, though, as the hugepage will be freed
1294 * once it is out of use. It also does not allow the counters to
1295 * go out of whack in adjust_pool_surplus() as we don't modify
1296 * the node values until we've gotten the hugepage and only the
1297 * per-node value is checked there.
1299 spin_lock(&hugetlb_lock
);
1300 if (h
->surplus_huge_pages
>= h
->nr_overcommit_huge_pages
) {
1301 spin_unlock(&hugetlb_lock
);
1305 h
->surplus_huge_pages
++;
1307 spin_unlock(&hugetlb_lock
);
1309 if (nid
== NUMA_NO_NODE
)
1310 page
= alloc_pages(htlb_alloc_mask(h
)|__GFP_COMP
|
1311 __GFP_REPEAT
|__GFP_NOWARN
,
1312 huge_page_order(h
));
1314 page
= alloc_pages_exact_node(nid
,
1315 htlb_alloc_mask(h
)|__GFP_COMP
|__GFP_THISNODE
|
1316 __GFP_REPEAT
|__GFP_NOWARN
, huge_page_order(h
));
1318 if (page
&& arch_prepare_hugepage(page
)) {
1319 __free_pages(page
, huge_page_order(h
));
1323 spin_lock(&hugetlb_lock
);
1325 INIT_LIST_HEAD(&page
->lru
);
1326 r_nid
= page_to_nid(page
);
1327 set_compound_page_dtor(page
, free_huge_page
);
1328 set_hugetlb_cgroup(page
, NULL
);
1330 * We incremented the global counters already
1332 h
->nr_huge_pages_node
[r_nid
]++;
1333 h
->surplus_huge_pages_node
[r_nid
]++;
1334 __count_vm_event(HTLB_BUDDY_PGALLOC
);
1337 h
->surplus_huge_pages
--;
1338 __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL
);
1340 spin_unlock(&hugetlb_lock
);
1346 * This allocation function is useful in the context where vma is irrelevant.
1347 * E.g. soft-offlining uses this function because it only cares physical
1348 * address of error page.
1350 struct page
*alloc_huge_page_node(struct hstate
*h
, int nid
)
1352 struct page
*page
= NULL
;
1354 spin_lock(&hugetlb_lock
);
1355 if (h
->free_huge_pages
- h
->resv_huge_pages
> 0)
1356 page
= dequeue_huge_page_node(h
, nid
);
1357 spin_unlock(&hugetlb_lock
);
1360 page
= alloc_buddy_huge_page(h
, nid
);
1366 * Increase the hugetlb pool such that it can accommodate a reservation
1369 static int gather_surplus_pages(struct hstate
*h
, int delta
)
1371 struct list_head surplus_list
;
1372 struct page
*page
, *tmp
;
1374 int needed
, allocated
;
1375 bool alloc_ok
= true;
1377 needed
= (h
->resv_huge_pages
+ delta
) - h
->free_huge_pages
;
1379 h
->resv_huge_pages
+= delta
;
1384 INIT_LIST_HEAD(&surplus_list
);
1388 spin_unlock(&hugetlb_lock
);
1389 for (i
= 0; i
< needed
; i
++) {
1390 page
= alloc_buddy_huge_page(h
, NUMA_NO_NODE
);
1395 list_add(&page
->lru
, &surplus_list
);
1400 * After retaking hugetlb_lock, we need to recalculate 'needed'
1401 * because either resv_huge_pages or free_huge_pages may have changed.
1403 spin_lock(&hugetlb_lock
);
1404 needed
= (h
->resv_huge_pages
+ delta
) -
1405 (h
->free_huge_pages
+ allocated
);
1410 * We were not able to allocate enough pages to
1411 * satisfy the entire reservation so we free what
1412 * we've allocated so far.
1417 * The surplus_list now contains _at_least_ the number of extra pages
1418 * needed to accommodate the reservation. Add the appropriate number
1419 * of pages to the hugetlb pool and free the extras back to the buddy
1420 * allocator. Commit the entire reservation here to prevent another
1421 * process from stealing the pages as they are added to the pool but
1422 * before they are reserved.
1424 needed
+= allocated
;
1425 h
->resv_huge_pages
+= delta
;
1428 /* Free the needed pages to the hugetlb pool */
1429 list_for_each_entry_safe(page
, tmp
, &surplus_list
, lru
) {
1433 * This page is now managed by the hugetlb allocator and has
1434 * no users -- drop the buddy allocator's reference.
1436 put_page_testzero(page
);
1437 VM_BUG_ON_PAGE(page_count(page
), page
);
1438 enqueue_huge_page(h
, page
);
1441 spin_unlock(&hugetlb_lock
);
1443 /* Free unnecessary surplus pages to the buddy allocator */
1444 list_for_each_entry_safe(page
, tmp
, &surplus_list
, lru
)
1446 spin_lock(&hugetlb_lock
);
1452 * When releasing a hugetlb pool reservation, any surplus pages that were
1453 * allocated to satisfy the reservation must be explicitly freed if they were
1455 * Called with hugetlb_lock held.
1457 static void return_unused_surplus_pages(struct hstate
*h
,
1458 unsigned long unused_resv_pages
)
1460 unsigned long nr_pages
;
1462 /* Uncommit the reservation */
1463 h
->resv_huge_pages
-= unused_resv_pages
;
1465 /* Cannot return gigantic pages currently */
1466 if (hstate_is_gigantic(h
))
1469 nr_pages
= min(unused_resv_pages
, h
->surplus_huge_pages
);
1472 * We want to release as many surplus pages as possible, spread
1473 * evenly across all nodes with memory. Iterate across these nodes
1474 * until we can no longer free unreserved surplus pages. This occurs
1475 * when the nodes with surplus pages have no free pages.
1476 * free_pool_huge_page() will balance the the freed pages across the
1477 * on-line nodes with memory and will handle the hstate accounting.
1479 while (nr_pages
--) {
1480 if (!free_pool_huge_page(h
, &node_states
[N_MEMORY
], 1))
1482 cond_resched_lock(&hugetlb_lock
);
1487 * vma_needs_reservation and vma_commit_reservation are used by the huge
1488 * page allocation routines to manage reservations.
1490 * vma_needs_reservation is called to determine if the huge page at addr
1491 * within the vma has an associated reservation. If a reservation is
1492 * needed, the value 1 is returned. The caller is then responsible for
1493 * managing the global reservation and subpool usage counts. After
1494 * the huge page has been allocated, vma_commit_reservation is called
1495 * to add the page to the reservation map.
1497 * In the normal case, vma_commit_reservation returns the same value
1498 * as the preceding vma_needs_reservation call. The only time this
1499 * is not the case is if a reserve map was changed between calls. It
1500 * is the responsibility of the caller to notice the difference and
1501 * take appropriate action.
1503 static long __vma_reservation_common(struct hstate
*h
,
1504 struct vm_area_struct
*vma
, unsigned long addr
,
1507 struct resv_map
*resv
;
1511 resv
= vma_resv_map(vma
);
1515 idx
= vma_hugecache_offset(h
, vma
, addr
);
1517 ret
= region_add(resv
, idx
, idx
+ 1);
1519 ret
= region_chg(resv
, idx
, idx
+ 1);
1521 if (vma
->vm_flags
& VM_MAYSHARE
)
1524 return ret
< 0 ? ret
: 0;
1527 static long vma_needs_reservation(struct hstate
*h
,
1528 struct vm_area_struct
*vma
, unsigned long addr
)
1530 return __vma_reservation_common(h
, vma
, addr
, false);
1533 static long vma_commit_reservation(struct hstate
*h
,
1534 struct vm_area_struct
*vma
, unsigned long addr
)
1536 return __vma_reservation_common(h
, vma
, addr
, true);
1539 static struct page
*alloc_huge_page(struct vm_area_struct
*vma
,
1540 unsigned long addr
, int avoid_reserve
)
1542 struct hugepage_subpool
*spool
= subpool_vma(vma
);
1543 struct hstate
*h
= hstate_vma(vma
);
1547 struct hugetlb_cgroup
*h_cg
;
1549 idx
= hstate_index(h
);
1551 * Processes that did not create the mapping will have no
1552 * reserves and will not have accounted against subpool
1553 * limit. Check that the subpool limit can be made before
1554 * satisfying the allocation MAP_NORESERVE mappings may also
1555 * need pages and subpool limit allocated allocated if no reserve
1558 chg
= vma_needs_reservation(h
, vma
, addr
);
1560 return ERR_PTR(-ENOMEM
);
1561 if (chg
|| avoid_reserve
)
1562 if (hugepage_subpool_get_pages(spool
, 1) < 0)
1563 return ERR_PTR(-ENOSPC
);
1565 ret
= hugetlb_cgroup_charge_cgroup(idx
, pages_per_huge_page(h
), &h_cg
);
1567 goto out_subpool_put
;
1569 spin_lock(&hugetlb_lock
);
1570 page
= dequeue_huge_page_vma(h
, vma
, addr
, avoid_reserve
, chg
);
1572 spin_unlock(&hugetlb_lock
);
1573 page
= alloc_buddy_huge_page(h
, NUMA_NO_NODE
);
1575 goto out_uncharge_cgroup
;
1577 spin_lock(&hugetlb_lock
);
1578 list_move(&page
->lru
, &h
->hugepage_activelist
);
1581 hugetlb_cgroup_commit_charge(idx
, pages_per_huge_page(h
), h_cg
, page
);
1582 spin_unlock(&hugetlb_lock
);
1584 set_page_private(page
, (unsigned long)spool
);
1586 commit
= vma_commit_reservation(h
, vma
, addr
);
1587 if (unlikely(chg
> commit
)) {
1589 * The page was added to the reservation map between
1590 * vma_needs_reservation and vma_commit_reservation.
1591 * This indicates a race with hugetlb_reserve_pages.
1592 * Adjust for the subpool count incremented above AND
1593 * in hugetlb_reserve_pages for the same page. Also,
1594 * the reservation count added in hugetlb_reserve_pages
1595 * no longer applies.
1599 rsv_adjust
= hugepage_subpool_put_pages(spool
, 1);
1600 hugetlb_acct_memory(h
, -rsv_adjust
);
1604 out_uncharge_cgroup
:
1605 hugetlb_cgroup_uncharge_cgroup(idx
, pages_per_huge_page(h
), h_cg
);
1607 if (chg
|| avoid_reserve
)
1608 hugepage_subpool_put_pages(spool
, 1);
1609 return ERR_PTR(-ENOSPC
);
1613 * alloc_huge_page()'s wrapper which simply returns the page if allocation
1614 * succeeds, otherwise NULL. This function is called from new_vma_page(),
1615 * where no ERR_VALUE is expected to be returned.
1617 struct page
*alloc_huge_page_noerr(struct vm_area_struct
*vma
,
1618 unsigned long addr
, int avoid_reserve
)
1620 struct page
*page
= alloc_huge_page(vma
, addr
, avoid_reserve
);
1626 int __weak
alloc_bootmem_huge_page(struct hstate
*h
)
1628 struct huge_bootmem_page
*m
;
1631 for_each_node_mask_to_alloc(h
, nr_nodes
, node
, &node_states
[N_MEMORY
]) {
1634 addr
= memblock_virt_alloc_try_nid_nopanic(
1635 huge_page_size(h
), huge_page_size(h
),
1636 0, BOOTMEM_ALLOC_ACCESSIBLE
, node
);
1639 * Use the beginning of the huge page to store the
1640 * huge_bootmem_page struct (until gather_bootmem
1641 * puts them into the mem_map).
1650 BUG_ON(!IS_ALIGNED(virt_to_phys(m
), huge_page_size(h
)));
1651 /* Put them into a private list first because mem_map is not up yet */
1652 list_add(&m
->list
, &huge_boot_pages
);
1657 static void __init
prep_compound_huge_page(struct page
*page
, int order
)
1659 if (unlikely(order
> (MAX_ORDER
- 1)))
1660 prep_compound_gigantic_page(page
, order
);
1662 prep_compound_page(page
, order
);
1665 /* Put bootmem huge pages into the standard lists after mem_map is up */
1666 static void __init
gather_bootmem_prealloc(void)
1668 struct huge_bootmem_page
*m
;
1670 list_for_each_entry(m
, &huge_boot_pages
, list
) {
1671 struct hstate
*h
= m
->hstate
;
1674 #ifdef CONFIG_HIGHMEM
1675 page
= pfn_to_page(m
->phys
>> PAGE_SHIFT
);
1676 memblock_free_late(__pa(m
),
1677 sizeof(struct huge_bootmem_page
));
1679 page
= virt_to_page(m
);
1681 WARN_ON(page_count(page
) != 1);
1682 prep_compound_huge_page(page
, h
->order
);
1683 WARN_ON(PageReserved(page
));
1684 prep_new_huge_page(h
, page
, page_to_nid(page
));
1686 * If we had gigantic hugepages allocated at boot time, we need
1687 * to restore the 'stolen' pages to totalram_pages in order to
1688 * fix confusing memory reports from free(1) and another
1689 * side-effects, like CommitLimit going negative.
1691 if (hstate_is_gigantic(h
))
1692 adjust_managed_page_count(page
, 1 << h
->order
);
1696 static void __init
hugetlb_hstate_alloc_pages(struct hstate
*h
)
1700 for (i
= 0; i
< h
->max_huge_pages
; ++i
) {
1701 if (hstate_is_gigantic(h
)) {
1702 if (!alloc_bootmem_huge_page(h
))
1704 } else if (!alloc_fresh_huge_page(h
,
1705 &node_states
[N_MEMORY
]))
1708 h
->max_huge_pages
= i
;
1711 static void __init
hugetlb_init_hstates(void)
1715 for_each_hstate(h
) {
1716 if (minimum_order
> huge_page_order(h
))
1717 minimum_order
= huge_page_order(h
);
1719 /* oversize hugepages were init'ed in early boot */
1720 if (!hstate_is_gigantic(h
))
1721 hugetlb_hstate_alloc_pages(h
);
1723 VM_BUG_ON(minimum_order
== UINT_MAX
);
1726 static char * __init
memfmt(char *buf
, unsigned long n
)
1728 if (n
>= (1UL << 30))
1729 sprintf(buf
, "%lu GB", n
>> 30);
1730 else if (n
>= (1UL << 20))
1731 sprintf(buf
, "%lu MB", n
>> 20);
1733 sprintf(buf
, "%lu KB", n
>> 10);
1737 static void __init
report_hugepages(void)
1741 for_each_hstate(h
) {
1743 pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n",
1744 memfmt(buf
, huge_page_size(h
)),
1745 h
->free_huge_pages
);
1749 #ifdef CONFIG_HIGHMEM
1750 static void try_to_free_low(struct hstate
*h
, unsigned long count
,
1751 nodemask_t
*nodes_allowed
)
1755 if (hstate_is_gigantic(h
))
1758 for_each_node_mask(i
, *nodes_allowed
) {
1759 struct page
*page
, *next
;
1760 struct list_head
*freel
= &h
->hugepage_freelists
[i
];
1761 list_for_each_entry_safe(page
, next
, freel
, lru
) {
1762 if (count
>= h
->nr_huge_pages
)
1764 if (PageHighMem(page
))
1766 list_del(&page
->lru
);
1767 update_and_free_page(h
, page
);
1768 h
->free_huge_pages
--;
1769 h
->free_huge_pages_node
[page_to_nid(page
)]--;
1774 static inline void try_to_free_low(struct hstate
*h
, unsigned long count
,
1775 nodemask_t
*nodes_allowed
)
1781 * Increment or decrement surplus_huge_pages. Keep node-specific counters
1782 * balanced by operating on them in a round-robin fashion.
1783 * Returns 1 if an adjustment was made.
1785 static int adjust_pool_surplus(struct hstate
*h
, nodemask_t
*nodes_allowed
,
1790 VM_BUG_ON(delta
!= -1 && delta
!= 1);
1793 for_each_node_mask_to_alloc(h
, nr_nodes
, node
, nodes_allowed
) {
1794 if (h
->surplus_huge_pages_node
[node
])
1798 for_each_node_mask_to_free(h
, nr_nodes
, node
, nodes_allowed
) {
1799 if (h
->surplus_huge_pages_node
[node
] <
1800 h
->nr_huge_pages_node
[node
])
1807 h
->surplus_huge_pages
+= delta
;
1808 h
->surplus_huge_pages_node
[node
] += delta
;
1812 #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)
1813 static unsigned long set_max_huge_pages(struct hstate
*h
, unsigned long count
,
1814 nodemask_t
*nodes_allowed
)
1816 unsigned long min_count
, ret
;
1818 if (hstate_is_gigantic(h
) && !gigantic_page_supported())
1819 return h
->max_huge_pages
;
1822 * Increase the pool size
1823 * First take pages out of surplus state. Then make up the
1824 * remaining difference by allocating fresh huge pages.
1826 * We might race with alloc_buddy_huge_page() here and be unable
1827 * to convert a surplus huge page to a normal huge page. That is
1828 * not critical, though, it just means the overall size of the
1829 * pool might be one hugepage larger than it needs to be, but
1830 * within all the constraints specified by the sysctls.
1832 spin_lock(&hugetlb_lock
);
1833 while (h
->surplus_huge_pages
&& count
> persistent_huge_pages(h
)) {
1834 if (!adjust_pool_surplus(h
, nodes_allowed
, -1))
1838 while (count
> persistent_huge_pages(h
)) {
1840 * If this allocation races such that we no longer need the
1841 * page, free_huge_page will handle it by freeing the page
1842 * and reducing the surplus.
1844 spin_unlock(&hugetlb_lock
);
1845 if (hstate_is_gigantic(h
))
1846 ret
= alloc_fresh_gigantic_page(h
, nodes_allowed
);
1848 ret
= alloc_fresh_huge_page(h
, nodes_allowed
);
1849 spin_lock(&hugetlb_lock
);
1853 /* Bail for signals. Probably ctrl-c from user */
1854 if (signal_pending(current
))
1859 * Decrease the pool size
1860 * First return free pages to the buddy allocator (being careful
1861 * to keep enough around to satisfy reservations). Then place
1862 * pages into surplus state as needed so the pool will shrink
1863 * to the desired size as pages become free.
1865 * By placing pages into the surplus state independent of the
1866 * overcommit value, we are allowing the surplus pool size to
1867 * exceed overcommit. There are few sane options here. Since
1868 * alloc_buddy_huge_page() is checking the global counter,
1869 * though, we'll note that we're not allowed to exceed surplus
1870 * and won't grow the pool anywhere else. Not until one of the
1871 * sysctls are changed, or the surplus pages go out of use.
1873 min_count
= h
->resv_huge_pages
+ h
->nr_huge_pages
- h
->free_huge_pages
;
1874 min_count
= max(count
, min_count
);
1875 try_to_free_low(h
, min_count
, nodes_allowed
);
1876 while (min_count
< persistent_huge_pages(h
)) {
1877 if (!free_pool_huge_page(h
, nodes_allowed
, 0))
1879 cond_resched_lock(&hugetlb_lock
);
1881 while (count
< persistent_huge_pages(h
)) {
1882 if (!adjust_pool_surplus(h
, nodes_allowed
, 1))
1886 ret
= persistent_huge_pages(h
);
1887 spin_unlock(&hugetlb_lock
);
1891 #define HSTATE_ATTR_RO(_name) \
1892 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
1894 #define HSTATE_ATTR(_name) \
1895 static struct kobj_attribute _name##_attr = \
1896 __ATTR(_name, 0644, _name##_show, _name##_store)
1898 static struct kobject
*hugepages_kobj
;
1899 static struct kobject
*hstate_kobjs
[HUGE_MAX_HSTATE
];
1901 static struct hstate
*kobj_to_node_hstate(struct kobject
*kobj
, int *nidp
);
1903 static struct hstate
*kobj_to_hstate(struct kobject
*kobj
, int *nidp
)
1907 for (i
= 0; i
< HUGE_MAX_HSTATE
; i
++)
1908 if (hstate_kobjs
[i
] == kobj
) {
1910 *nidp
= NUMA_NO_NODE
;
1914 return kobj_to_node_hstate(kobj
, nidp
);
1917 static ssize_t
nr_hugepages_show_common(struct kobject
*kobj
,
1918 struct kobj_attribute
*attr
, char *buf
)
1921 unsigned long nr_huge_pages
;
1924 h
= kobj_to_hstate(kobj
, &nid
);
1925 if (nid
== NUMA_NO_NODE
)
1926 nr_huge_pages
= h
->nr_huge_pages
;
1928 nr_huge_pages
= h
->nr_huge_pages_node
[nid
];
1930 return sprintf(buf
, "%lu\n", nr_huge_pages
);
1933 static ssize_t
__nr_hugepages_store_common(bool obey_mempolicy
,
1934 struct hstate
*h
, int nid
,
1935 unsigned long count
, size_t len
)
1938 NODEMASK_ALLOC(nodemask_t
, nodes_allowed
, GFP_KERNEL
| __GFP_NORETRY
);
1940 if (hstate_is_gigantic(h
) && !gigantic_page_supported()) {
1945 if (nid
== NUMA_NO_NODE
) {
1947 * global hstate attribute
1949 if (!(obey_mempolicy
&&
1950 init_nodemask_of_mempolicy(nodes_allowed
))) {
1951 NODEMASK_FREE(nodes_allowed
);
1952 nodes_allowed
= &node_states
[N_MEMORY
];
1954 } else if (nodes_allowed
) {
1956 * per node hstate attribute: adjust count to global,
1957 * but restrict alloc/free to the specified node.
1959 count
+= h
->nr_huge_pages
- h
->nr_huge_pages_node
[nid
];
1960 init_nodemask_of_node(nodes_allowed
, nid
);
1962 nodes_allowed
= &node_states
[N_MEMORY
];
1964 h
->max_huge_pages
= set_max_huge_pages(h
, count
, nodes_allowed
);
1966 if (nodes_allowed
!= &node_states
[N_MEMORY
])
1967 NODEMASK_FREE(nodes_allowed
);
1971 NODEMASK_FREE(nodes_allowed
);
1975 static ssize_t
nr_hugepages_store_common(bool obey_mempolicy
,
1976 struct kobject
*kobj
, const char *buf
,
1980 unsigned long count
;
1984 err
= kstrtoul(buf
, 10, &count
);
1988 h
= kobj_to_hstate(kobj
, &nid
);
1989 return __nr_hugepages_store_common(obey_mempolicy
, h
, nid
, count
, len
);
1992 static ssize_t
nr_hugepages_show(struct kobject
*kobj
,
1993 struct kobj_attribute
*attr
, char *buf
)
1995 return nr_hugepages_show_common(kobj
, attr
, buf
);
1998 static ssize_t
nr_hugepages_store(struct kobject
*kobj
,
1999 struct kobj_attribute
*attr
, const char *buf
, size_t len
)
2001 return nr_hugepages_store_common(false, kobj
, buf
, len
);
2003 HSTATE_ATTR(nr_hugepages
);
2008 * hstate attribute for optionally mempolicy-based constraint on persistent
2009 * huge page alloc/free.
2011 static ssize_t
nr_hugepages_mempolicy_show(struct kobject
*kobj
,
2012 struct kobj_attribute
*attr
, char *buf
)
2014 return nr_hugepages_show_common(kobj
, attr
, buf
);
2017 static ssize_t
nr_hugepages_mempolicy_store(struct kobject
*kobj
,
2018 struct kobj_attribute
*attr
, const char *buf
, size_t len
)
2020 return nr_hugepages_store_common(true, kobj
, buf
, len
);
2022 HSTATE_ATTR(nr_hugepages_mempolicy
);
2026 static ssize_t
nr_overcommit_hugepages_show(struct kobject
*kobj
,
2027 struct kobj_attribute
*attr
, char *buf
)
2029 struct hstate
*h
= kobj_to_hstate(kobj
, NULL
);
2030 return sprintf(buf
, "%lu\n", h
->nr_overcommit_huge_pages
);
2033 static ssize_t
nr_overcommit_hugepages_store(struct kobject
*kobj
,
2034 struct kobj_attribute
*attr
, const char *buf
, size_t count
)
2037 unsigned long input
;
2038 struct hstate
*h
= kobj_to_hstate(kobj
, NULL
);
2040 if (hstate_is_gigantic(h
))
2043 err
= kstrtoul(buf
, 10, &input
);
2047 spin_lock(&hugetlb_lock
);
2048 h
->nr_overcommit_huge_pages
= input
;
2049 spin_unlock(&hugetlb_lock
);
2053 HSTATE_ATTR(nr_overcommit_hugepages
);
2055 static ssize_t
free_hugepages_show(struct kobject
*kobj
,
2056 struct kobj_attribute
*attr
, char *buf
)
2059 unsigned long free_huge_pages
;
2062 h
= kobj_to_hstate(kobj
, &nid
);
2063 if (nid
== NUMA_NO_NODE
)
2064 free_huge_pages
= h
->free_huge_pages
;
2066 free_huge_pages
= h
->free_huge_pages_node
[nid
];
2068 return sprintf(buf
, "%lu\n", free_huge_pages
);
2070 HSTATE_ATTR_RO(free_hugepages
);
2072 static ssize_t
resv_hugepages_show(struct kobject
*kobj
,
2073 struct kobj_attribute
*attr
, char *buf
)
2075 struct hstate
*h
= kobj_to_hstate(kobj
, NULL
);
2076 return sprintf(buf
, "%lu\n", h
->resv_huge_pages
);
2078 HSTATE_ATTR_RO(resv_hugepages
);
2080 static ssize_t
surplus_hugepages_show(struct kobject
*kobj
,
2081 struct kobj_attribute
*attr
, char *buf
)
2084 unsigned long surplus_huge_pages
;
2087 h
= kobj_to_hstate(kobj
, &nid
);
2088 if (nid
== NUMA_NO_NODE
)
2089 surplus_huge_pages
= h
->surplus_huge_pages
;
2091 surplus_huge_pages
= h
->surplus_huge_pages_node
[nid
];
2093 return sprintf(buf
, "%lu\n", surplus_huge_pages
);
2095 HSTATE_ATTR_RO(surplus_hugepages
);
2097 static struct attribute
*hstate_attrs
[] = {
2098 &nr_hugepages_attr
.attr
,
2099 &nr_overcommit_hugepages_attr
.attr
,
2100 &free_hugepages_attr
.attr
,
2101 &resv_hugepages_attr
.attr
,
2102 &surplus_hugepages_attr
.attr
,
2104 &nr_hugepages_mempolicy_attr
.attr
,
2109 static struct attribute_group hstate_attr_group
= {
2110 .attrs
= hstate_attrs
,
2113 static int hugetlb_sysfs_add_hstate(struct hstate
*h
, struct kobject
*parent
,
2114 struct kobject
**hstate_kobjs
,
2115 struct attribute_group
*hstate_attr_group
)
2118 int hi
= hstate_index(h
);
2120 hstate_kobjs
[hi
] = kobject_create_and_add(h
->name
, parent
);
2121 if (!hstate_kobjs
[hi
])
2124 retval
= sysfs_create_group(hstate_kobjs
[hi
], hstate_attr_group
);
2126 kobject_put(hstate_kobjs
[hi
]);
2131 static void __init
hugetlb_sysfs_init(void)
2136 hugepages_kobj
= kobject_create_and_add("hugepages", mm_kobj
);
2137 if (!hugepages_kobj
)
2140 for_each_hstate(h
) {
2141 err
= hugetlb_sysfs_add_hstate(h
, hugepages_kobj
,
2142 hstate_kobjs
, &hstate_attr_group
);
2144 pr_err("Hugetlb: Unable to add hstate %s", h
->name
);
2151 * node_hstate/s - associate per node hstate attributes, via their kobjects,
2152 * with node devices in node_devices[] using a parallel array. The array
2153 * index of a node device or _hstate == node id.
2154 * This is here to avoid any static dependency of the node device driver, in
2155 * the base kernel, on the hugetlb module.
2157 struct node_hstate
{
2158 struct kobject
*hugepages_kobj
;
2159 struct kobject
*hstate_kobjs
[HUGE_MAX_HSTATE
];
2161 struct node_hstate node_hstates
[MAX_NUMNODES
];
2164 * A subset of global hstate attributes for node devices
2166 static struct attribute
*per_node_hstate_attrs
[] = {
2167 &nr_hugepages_attr
.attr
,
2168 &free_hugepages_attr
.attr
,
2169 &surplus_hugepages_attr
.attr
,
2173 static struct attribute_group per_node_hstate_attr_group
= {
2174 .attrs
= per_node_hstate_attrs
,
2178 * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj.
2179 * Returns node id via non-NULL nidp.
2181 static struct hstate
*kobj_to_node_hstate(struct kobject
*kobj
, int *nidp
)
2185 for (nid
= 0; nid
< nr_node_ids
; nid
++) {
2186 struct node_hstate
*nhs
= &node_hstates
[nid
];
2188 for (i
= 0; i
< HUGE_MAX_HSTATE
; i
++)
2189 if (nhs
->hstate_kobjs
[i
] == kobj
) {
2201 * Unregister hstate attributes from a single node device.
2202 * No-op if no hstate attributes attached.
2204 static void hugetlb_unregister_node(struct node
*node
)
2207 struct node_hstate
*nhs
= &node_hstates
[node
->dev
.id
];
2209 if (!nhs
->hugepages_kobj
)
2210 return; /* no hstate attributes */
2212 for_each_hstate(h
) {
2213 int idx
= hstate_index(h
);
2214 if (nhs
->hstate_kobjs
[idx
]) {
2215 kobject_put(nhs
->hstate_kobjs
[idx
]);
2216 nhs
->hstate_kobjs
[idx
] = NULL
;
2220 kobject_put(nhs
->hugepages_kobj
);
2221 nhs
->hugepages_kobj
= NULL
;
2225 * hugetlb module exit: unregister hstate attributes from node devices
2228 static void hugetlb_unregister_all_nodes(void)
2233 * disable node device registrations.
2235 register_hugetlbfs_with_node(NULL
, NULL
);
2238 * remove hstate attributes from any nodes that have them.
2240 for (nid
= 0; nid
< nr_node_ids
; nid
++)
2241 hugetlb_unregister_node(node_devices
[nid
]);
2245 * Register hstate attributes for a single node device.
2246 * No-op if attributes already registered.
2248 static void hugetlb_register_node(struct node
*node
)
2251 struct node_hstate
*nhs
= &node_hstates
[node
->dev
.id
];
2254 if (nhs
->hugepages_kobj
)
2255 return; /* already allocated */
2257 nhs
->hugepages_kobj
= kobject_create_and_add("hugepages",
2259 if (!nhs
->hugepages_kobj
)
2262 for_each_hstate(h
) {
2263 err
= hugetlb_sysfs_add_hstate(h
, nhs
->hugepages_kobj
,
2265 &per_node_hstate_attr_group
);
2267 pr_err("Hugetlb: Unable to add hstate %s for node %d\n",
2268 h
->name
, node
->dev
.id
);
2269 hugetlb_unregister_node(node
);
2276 * hugetlb init time: register hstate attributes for all registered node
2277 * devices of nodes that have memory. All on-line nodes should have
2278 * registered their associated device by this time.
2280 static void __init
hugetlb_register_all_nodes(void)
2284 for_each_node_state(nid
, N_MEMORY
) {
2285 struct node
*node
= node_devices
[nid
];
2286 if (node
->dev
.id
== nid
)
2287 hugetlb_register_node(node
);
2291 * Let the node device driver know we're here so it can
2292 * [un]register hstate attributes on node hotplug.
2294 register_hugetlbfs_with_node(hugetlb_register_node
,
2295 hugetlb_unregister_node
);
2297 #else /* !CONFIG_NUMA */
2299 static struct hstate
*kobj_to_node_hstate(struct kobject
*kobj
, int *nidp
)
2307 static void hugetlb_unregister_all_nodes(void) { }
2309 static void hugetlb_register_all_nodes(void) { }
2313 static void __exit
hugetlb_exit(void)
2317 hugetlb_unregister_all_nodes();
2319 for_each_hstate(h
) {
2320 kobject_put(hstate_kobjs
[hstate_index(h
)]);
2323 kobject_put(hugepages_kobj
);
2324 kfree(htlb_fault_mutex_table
);
2326 module_exit(hugetlb_exit
);
2328 static int __init
hugetlb_init(void)
2332 if (!hugepages_supported())
2335 if (!size_to_hstate(default_hstate_size
)) {
2336 default_hstate_size
= HPAGE_SIZE
;
2337 if (!size_to_hstate(default_hstate_size
))
2338 hugetlb_add_hstate(HUGETLB_PAGE_ORDER
);
2340 default_hstate_idx
= hstate_index(size_to_hstate(default_hstate_size
));
2341 if (default_hstate_max_huge_pages
)
2342 default_hstate
.max_huge_pages
= default_hstate_max_huge_pages
;
2344 hugetlb_init_hstates();
2345 gather_bootmem_prealloc();
2348 hugetlb_sysfs_init();
2349 hugetlb_register_all_nodes();
2350 hugetlb_cgroup_file_init();
2353 num_fault_mutexes
= roundup_pow_of_two(8 * num_possible_cpus());
2355 num_fault_mutexes
= 1;
2357 htlb_fault_mutex_table
=
2358 kmalloc(sizeof(struct mutex
) * num_fault_mutexes
, GFP_KERNEL
);
2359 BUG_ON(!htlb_fault_mutex_table
);
2361 for (i
= 0; i
< num_fault_mutexes
; i
++)
2362 mutex_init(&htlb_fault_mutex_table
[i
]);
2365 module_init(hugetlb_init
);
2367 /* Should be called on processing a hugepagesz=... option */
2368 void __init
hugetlb_add_hstate(unsigned order
)
2373 if (size_to_hstate(PAGE_SIZE
<< order
)) {
2374 pr_warning("hugepagesz= specified twice, ignoring\n");
2377 BUG_ON(hugetlb_max_hstate
>= HUGE_MAX_HSTATE
);
2379 h
= &hstates
[hugetlb_max_hstate
++];
2381 h
->mask
= ~((1ULL << (order
+ PAGE_SHIFT
)) - 1);
2382 h
->nr_huge_pages
= 0;
2383 h
->free_huge_pages
= 0;
2384 for (i
= 0; i
< MAX_NUMNODES
; ++i
)
2385 INIT_LIST_HEAD(&h
->hugepage_freelists
[i
]);
2386 INIT_LIST_HEAD(&h
->hugepage_activelist
);
2387 h
->next_nid_to_alloc
= first_node(node_states
[N_MEMORY
]);
2388 h
->next_nid_to_free
= first_node(node_states
[N_MEMORY
]);
2389 snprintf(h
->name
, HSTATE_NAME_LEN
, "hugepages-%lukB",
2390 huge_page_size(h
)/1024);
2395 static int __init
hugetlb_nrpages_setup(char *s
)
2398 static unsigned long *last_mhp
;
2401 * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter yet,
2402 * so this hugepages= parameter goes to the "default hstate".
2404 if (!hugetlb_max_hstate
)
2405 mhp
= &default_hstate_max_huge_pages
;
2407 mhp
= &parsed_hstate
->max_huge_pages
;
2409 if (mhp
== last_mhp
) {
2410 pr_warning("hugepages= specified twice without "
2411 "interleaving hugepagesz=, ignoring\n");
2415 if (sscanf(s
, "%lu", mhp
) <= 0)
2419 * Global state is always initialized later in hugetlb_init.
2420 * But we need to allocate >= MAX_ORDER hstates here early to still
2421 * use the bootmem allocator.
2423 if (hugetlb_max_hstate
&& parsed_hstate
->order
>= MAX_ORDER
)
2424 hugetlb_hstate_alloc_pages(parsed_hstate
);
2430 __setup("hugepages=", hugetlb_nrpages_setup
);
2432 static int __init
hugetlb_default_setup(char *s
)
2434 default_hstate_size
= memparse(s
, &s
);
2437 __setup("default_hugepagesz=", hugetlb_default_setup
);
2439 static unsigned int cpuset_mems_nr(unsigned int *array
)
2442 unsigned int nr
= 0;
2444 for_each_node_mask(node
, cpuset_current_mems_allowed
)
2450 #ifdef CONFIG_SYSCTL
2451 static int hugetlb_sysctl_handler_common(bool obey_mempolicy
,
2452 struct ctl_table
*table
, int write
,
2453 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
2455 struct hstate
*h
= &default_hstate
;
2456 unsigned long tmp
= h
->max_huge_pages
;
2459 if (!hugepages_supported())
2463 table
->maxlen
= sizeof(unsigned long);
2464 ret
= proc_doulongvec_minmax(table
, write
, buffer
, length
, ppos
);
2469 ret
= __nr_hugepages_store_common(obey_mempolicy
, h
,
2470 NUMA_NO_NODE
, tmp
, *length
);
2475 int hugetlb_sysctl_handler(struct ctl_table
*table
, int write
,
2476 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
2479 return hugetlb_sysctl_handler_common(false, table
, write
,
2480 buffer
, length
, ppos
);
2484 int hugetlb_mempolicy_sysctl_handler(struct ctl_table
*table
, int write
,
2485 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
2487 return hugetlb_sysctl_handler_common(true, table
, write
,
2488 buffer
, length
, ppos
);
2490 #endif /* CONFIG_NUMA */
2492 int hugetlb_overcommit_handler(struct ctl_table
*table
, int write
,
2493 void __user
*buffer
,
2494 size_t *length
, loff_t
*ppos
)
2496 struct hstate
*h
= &default_hstate
;
2500 if (!hugepages_supported())
2503 tmp
= h
->nr_overcommit_huge_pages
;
2505 if (write
&& hstate_is_gigantic(h
))
2509 table
->maxlen
= sizeof(unsigned long);
2510 ret
= proc_doulongvec_minmax(table
, write
, buffer
, length
, ppos
);
2515 spin_lock(&hugetlb_lock
);
2516 h
->nr_overcommit_huge_pages
= tmp
;
2517 spin_unlock(&hugetlb_lock
);
2523 #endif /* CONFIG_SYSCTL */
2525 void hugetlb_report_meminfo(struct seq_file
*m
)
2527 struct hstate
*h
= &default_hstate
;
2528 if (!hugepages_supported())
2531 "HugePages_Total: %5lu\n"
2532 "HugePages_Free: %5lu\n"
2533 "HugePages_Rsvd: %5lu\n"
2534 "HugePages_Surp: %5lu\n"
2535 "Hugepagesize: %8lu kB\n",
2539 h
->surplus_huge_pages
,
2540 1UL << (huge_page_order(h
) + PAGE_SHIFT
- 10));
2543 int hugetlb_report_node_meminfo(int nid
, char *buf
)
2545 struct hstate
*h
= &default_hstate
;
2546 if (!hugepages_supported())
2549 "Node %d HugePages_Total: %5u\n"
2550 "Node %d HugePages_Free: %5u\n"
2551 "Node %d HugePages_Surp: %5u\n",
2552 nid
, h
->nr_huge_pages_node
[nid
],
2553 nid
, h
->free_huge_pages_node
[nid
],
2554 nid
, h
->surplus_huge_pages_node
[nid
]);
2557 void hugetlb_show_meminfo(void)
2562 if (!hugepages_supported())
2565 for_each_node_state(nid
, N_MEMORY
)
2567 pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n",
2569 h
->nr_huge_pages_node
[nid
],
2570 h
->free_huge_pages_node
[nid
],
2571 h
->surplus_huge_pages_node
[nid
],
2572 1UL << (huge_page_order(h
) + PAGE_SHIFT
- 10));
2575 /* Return the number pages of memory we physically have, in PAGE_SIZE units. */
2576 unsigned long hugetlb_total_pages(void)
2579 unsigned long nr_total_pages
= 0;
2582 nr_total_pages
+= h
->nr_huge_pages
* pages_per_huge_page(h
);
2583 return nr_total_pages
;
2586 static int hugetlb_acct_memory(struct hstate
*h
, long delta
)
2590 spin_lock(&hugetlb_lock
);
2592 * When cpuset is configured, it breaks the strict hugetlb page
2593 * reservation as the accounting is done on a global variable. Such
2594 * reservation is completely rubbish in the presence of cpuset because
2595 * the reservation is not checked against page availability for the
2596 * current cpuset. Application can still potentially OOM'ed by kernel
2597 * with lack of free htlb page in cpuset that the task is in.
2598 * Attempt to enforce strict accounting with cpuset is almost
2599 * impossible (or too ugly) because cpuset is too fluid that
2600 * task or memory node can be dynamically moved between cpusets.
2602 * The change of semantics for shared hugetlb mapping with cpuset is
2603 * undesirable. However, in order to preserve some of the semantics,
2604 * we fall back to check against current free page availability as
2605 * a best attempt and hopefully to minimize the impact of changing
2606 * semantics that cpuset has.
2609 if (gather_surplus_pages(h
, delta
) < 0)
2612 if (delta
> cpuset_mems_nr(h
->free_huge_pages_node
)) {
2613 return_unused_surplus_pages(h
, delta
);
2620 return_unused_surplus_pages(h
, (unsigned long) -delta
);
2623 spin_unlock(&hugetlb_lock
);
2627 static void hugetlb_vm_op_open(struct vm_area_struct
*vma
)
2629 struct resv_map
*resv
= vma_resv_map(vma
);
2632 * This new VMA should share its siblings reservation map if present.
2633 * The VMA will only ever have a valid reservation map pointer where
2634 * it is being copied for another still existing VMA. As that VMA
2635 * has a reference to the reservation map it cannot disappear until
2636 * after this open call completes. It is therefore safe to take a
2637 * new reference here without additional locking.
2639 if (resv
&& is_vma_resv_set(vma
, HPAGE_RESV_OWNER
))
2640 kref_get(&resv
->refs
);
2643 static void hugetlb_vm_op_close(struct vm_area_struct
*vma
)
2645 struct hstate
*h
= hstate_vma(vma
);
2646 struct resv_map
*resv
= vma_resv_map(vma
);
2647 struct hugepage_subpool
*spool
= subpool_vma(vma
);
2648 unsigned long reserve
, start
, end
;
2651 if (!resv
|| !is_vma_resv_set(vma
, HPAGE_RESV_OWNER
))
2654 start
= vma_hugecache_offset(h
, vma
, vma
->vm_start
);
2655 end
= vma_hugecache_offset(h
, vma
, vma
->vm_end
);
2657 reserve
= (end
- start
) - region_count(resv
, start
, end
);
2659 kref_put(&resv
->refs
, resv_map_release
);
2663 * Decrement reserve counts. The global reserve count may be
2664 * adjusted if the subpool has a minimum size.
2666 gbl_reserve
= hugepage_subpool_put_pages(spool
, reserve
);
2667 hugetlb_acct_memory(h
, -gbl_reserve
);
2672 * We cannot handle pagefaults against hugetlb pages at all. They cause
2673 * handle_mm_fault() to try to instantiate regular-sized pages in the
2674 * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get
2677 static int hugetlb_vm_op_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
2683 const struct vm_operations_struct hugetlb_vm_ops
= {
2684 .fault
= hugetlb_vm_op_fault
,
2685 .open
= hugetlb_vm_op_open
,
2686 .close
= hugetlb_vm_op_close
,
2689 static pte_t
make_huge_pte(struct vm_area_struct
*vma
, struct page
*page
,
2695 entry
= huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page
,
2696 vma
->vm_page_prot
)));
2698 entry
= huge_pte_wrprotect(mk_huge_pte(page
,
2699 vma
->vm_page_prot
));
2701 entry
= pte_mkyoung(entry
);
2702 entry
= pte_mkhuge(entry
);
2703 entry
= arch_make_huge_pte(entry
, vma
, page
, writable
);
2708 static void set_huge_ptep_writable(struct vm_area_struct
*vma
,
2709 unsigned long address
, pte_t
*ptep
)
2713 entry
= huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep
)));
2714 if (huge_ptep_set_access_flags(vma
, address
, ptep
, entry
, 1))
2715 update_mmu_cache(vma
, address
, ptep
);
2718 static int is_hugetlb_entry_migration(pte_t pte
)
2722 if (huge_pte_none(pte
) || pte_present(pte
))
2724 swp
= pte_to_swp_entry(pte
);
2725 if (non_swap_entry(swp
) && is_migration_entry(swp
))
2731 static int is_hugetlb_entry_hwpoisoned(pte_t pte
)
2735 if (huge_pte_none(pte
) || pte_present(pte
))
2737 swp
= pte_to_swp_entry(pte
);
2738 if (non_swap_entry(swp
) && is_hwpoison_entry(swp
))
2744 int copy_hugetlb_page_range(struct mm_struct
*dst
, struct mm_struct
*src
,
2745 struct vm_area_struct
*vma
)
2747 pte_t
*src_pte
, *dst_pte
, entry
;
2748 struct page
*ptepage
;
2751 struct hstate
*h
= hstate_vma(vma
);
2752 unsigned long sz
= huge_page_size(h
);
2753 unsigned long mmun_start
; /* For mmu_notifiers */
2754 unsigned long mmun_end
; /* For mmu_notifiers */
2757 cow
= (vma
->vm_flags
& (VM_SHARED
| VM_MAYWRITE
)) == VM_MAYWRITE
;
2759 mmun_start
= vma
->vm_start
;
2760 mmun_end
= vma
->vm_end
;
2762 mmu_notifier_invalidate_range_start(src
, mmun_start
, mmun_end
);
2764 for (addr
= vma
->vm_start
; addr
< vma
->vm_end
; addr
+= sz
) {
2765 spinlock_t
*src_ptl
, *dst_ptl
;
2766 src_pte
= huge_pte_offset(src
, addr
);
2769 dst_pte
= huge_pte_alloc(dst
, addr
, sz
);
2775 /* If the pagetables are shared don't copy or take references */
2776 if (dst_pte
== src_pte
)
2779 dst_ptl
= huge_pte_lock(h
, dst
, dst_pte
);
2780 src_ptl
= huge_pte_lockptr(h
, src
, src_pte
);
2781 spin_lock_nested(src_ptl
, SINGLE_DEPTH_NESTING
);
2782 entry
= huge_ptep_get(src_pte
);
2783 if (huge_pte_none(entry
)) { /* skip none entry */
2785 } else if (unlikely(is_hugetlb_entry_migration(entry
) ||
2786 is_hugetlb_entry_hwpoisoned(entry
))) {
2787 swp_entry_t swp_entry
= pte_to_swp_entry(entry
);
2789 if (is_write_migration_entry(swp_entry
) && cow
) {
2791 * COW mappings require pages in both
2792 * parent and child to be set to read.
2794 make_migration_entry_read(&swp_entry
);
2795 entry
= swp_entry_to_pte(swp_entry
);
2796 set_huge_pte_at(src
, addr
, src_pte
, entry
);
2798 set_huge_pte_at(dst
, addr
, dst_pte
, entry
);
2801 huge_ptep_set_wrprotect(src
, addr
, src_pte
);
2802 mmu_notifier_invalidate_range(src
, mmun_start
,
2805 entry
= huge_ptep_get(src_pte
);
2806 ptepage
= pte_page(entry
);
2808 page_dup_rmap(ptepage
);
2809 set_huge_pte_at(dst
, addr
, dst_pte
, entry
);
2811 spin_unlock(src_ptl
);
2812 spin_unlock(dst_ptl
);
2816 mmu_notifier_invalidate_range_end(src
, mmun_start
, mmun_end
);
2821 void __unmap_hugepage_range(struct mmu_gather
*tlb
, struct vm_area_struct
*vma
,
2822 unsigned long start
, unsigned long end
,
2823 struct page
*ref_page
)
2825 int force_flush
= 0;
2826 struct mm_struct
*mm
= vma
->vm_mm
;
2827 unsigned long address
;
2832 struct hstate
*h
= hstate_vma(vma
);
2833 unsigned long sz
= huge_page_size(h
);
2834 const unsigned long mmun_start
= start
; /* For mmu_notifiers */
2835 const unsigned long mmun_end
= end
; /* For mmu_notifiers */
2837 WARN_ON(!is_vm_hugetlb_page(vma
));
2838 BUG_ON(start
& ~huge_page_mask(h
));
2839 BUG_ON(end
& ~huge_page_mask(h
));
2841 tlb_start_vma(tlb
, vma
);
2842 mmu_notifier_invalidate_range_start(mm
, mmun_start
, mmun_end
);
2845 for (; address
< end
; address
+= sz
) {
2846 ptep
= huge_pte_offset(mm
, address
);
2850 ptl
= huge_pte_lock(h
, mm
, ptep
);
2851 if (huge_pmd_unshare(mm
, &address
, ptep
))
2854 pte
= huge_ptep_get(ptep
);
2855 if (huge_pte_none(pte
))
2859 * Migrating hugepage or HWPoisoned hugepage is already
2860 * unmapped and its refcount is dropped, so just clear pte here.
2862 if (unlikely(!pte_present(pte
))) {
2863 huge_pte_clear(mm
, address
, ptep
);
2867 page
= pte_page(pte
);
2869 * If a reference page is supplied, it is because a specific
2870 * page is being unmapped, not a range. Ensure the page we
2871 * are about to unmap is the actual page of interest.
2874 if (page
!= ref_page
)
2878 * Mark the VMA as having unmapped its page so that
2879 * future faults in this VMA will fail rather than
2880 * looking like data was lost
2882 set_vma_resv_flags(vma
, HPAGE_RESV_UNMAPPED
);
2885 pte
= huge_ptep_get_and_clear(mm
, address
, ptep
);
2886 tlb_remove_tlb_entry(tlb
, ptep
, address
);
2887 if (huge_pte_dirty(pte
))
2888 set_page_dirty(page
);
2890 page_remove_rmap(page
);
2891 force_flush
= !__tlb_remove_page(tlb
, page
);
2897 /* Bail out after unmapping reference page if supplied */
2906 * mmu_gather ran out of room to batch pages, we break out of
2907 * the PTE lock to avoid doing the potential expensive TLB invalidate
2908 * and page-free while holding it.
2913 if (address
< end
&& !ref_page
)
2916 mmu_notifier_invalidate_range_end(mm
, mmun_start
, mmun_end
);
2917 tlb_end_vma(tlb
, vma
);
2920 void __unmap_hugepage_range_final(struct mmu_gather
*tlb
,
2921 struct vm_area_struct
*vma
, unsigned long start
,
2922 unsigned long end
, struct page
*ref_page
)
2924 __unmap_hugepage_range(tlb
, vma
, start
, end
, ref_page
);
2927 * Clear this flag so that x86's huge_pmd_share page_table_shareable
2928 * test will fail on a vma being torn down, and not grab a page table
2929 * on its way out. We're lucky that the flag has such an appropriate
2930 * name, and can in fact be safely cleared here. We could clear it
2931 * before the __unmap_hugepage_range above, but all that's necessary
2932 * is to clear it before releasing the i_mmap_rwsem. This works
2933 * because in the context this is called, the VMA is about to be
2934 * destroyed and the i_mmap_rwsem is held.
2936 vma
->vm_flags
&= ~VM_MAYSHARE
;
2939 void unmap_hugepage_range(struct vm_area_struct
*vma
, unsigned long start
,
2940 unsigned long end
, struct page
*ref_page
)
2942 struct mm_struct
*mm
;
2943 struct mmu_gather tlb
;
2947 tlb_gather_mmu(&tlb
, mm
, start
, end
);
2948 __unmap_hugepage_range(&tlb
, vma
, start
, end
, ref_page
);
2949 tlb_finish_mmu(&tlb
, start
, end
);
2953 * This is called when the original mapper is failing to COW a MAP_PRIVATE
2954 * mappping it owns the reserve page for. The intention is to unmap the page
2955 * from other VMAs and let the children be SIGKILLed if they are faulting the
2958 static void unmap_ref_private(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
2959 struct page
*page
, unsigned long address
)
2961 struct hstate
*h
= hstate_vma(vma
);
2962 struct vm_area_struct
*iter_vma
;
2963 struct address_space
*mapping
;
2967 * vm_pgoff is in PAGE_SIZE units, hence the different calculation
2968 * from page cache lookup which is in HPAGE_SIZE units.
2970 address
= address
& huge_page_mask(h
);
2971 pgoff
= ((address
- vma
->vm_start
) >> PAGE_SHIFT
) +
2973 mapping
= file_inode(vma
->vm_file
)->i_mapping
;
2976 * Take the mapping lock for the duration of the table walk. As
2977 * this mapping should be shared between all the VMAs,
2978 * __unmap_hugepage_range() is called as the lock is already held
2980 i_mmap_lock_write(mapping
);
2981 vma_interval_tree_foreach(iter_vma
, &mapping
->i_mmap
, pgoff
, pgoff
) {
2982 /* Do not unmap the current VMA */
2983 if (iter_vma
== vma
)
2987 * Unmap the page from other VMAs without their own reserves.
2988 * They get marked to be SIGKILLed if they fault in these
2989 * areas. This is because a future no-page fault on this VMA
2990 * could insert a zeroed page instead of the data existing
2991 * from the time of fork. This would look like data corruption
2993 if (!is_vma_resv_set(iter_vma
, HPAGE_RESV_OWNER
))
2994 unmap_hugepage_range(iter_vma
, address
,
2995 address
+ huge_page_size(h
), page
);
2997 i_mmap_unlock_write(mapping
);
3001 * Hugetlb_cow() should be called with page lock of the original hugepage held.
3002 * Called with hugetlb_instantiation_mutex held and pte_page locked so we
3003 * cannot race with other handlers or page migration.
3004 * Keep the pte_same checks anyway to make transition from the mutex easier.
3006 static int hugetlb_cow(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
3007 unsigned long address
, pte_t
*ptep
, pte_t pte
,
3008 struct page
*pagecache_page
, spinlock_t
*ptl
)
3010 struct hstate
*h
= hstate_vma(vma
);
3011 struct page
*old_page
, *new_page
;
3012 int ret
= 0, outside_reserve
= 0;
3013 unsigned long mmun_start
; /* For mmu_notifiers */
3014 unsigned long mmun_end
; /* For mmu_notifiers */
3016 old_page
= pte_page(pte
);
3019 /* If no-one else is actually using this page, avoid the copy
3020 * and just make the page writable */
3021 if (page_mapcount(old_page
) == 1 && PageAnon(old_page
)) {
3022 page_move_anon_rmap(old_page
, vma
, address
);
3023 set_huge_ptep_writable(vma
, address
, ptep
);
3028 * If the process that created a MAP_PRIVATE mapping is about to
3029 * perform a COW due to a shared page count, attempt to satisfy
3030 * the allocation without using the existing reserves. The pagecache
3031 * page is used to determine if the reserve at this address was
3032 * consumed or not. If reserves were used, a partial faulted mapping
3033 * at the time of fork() could consume its reserves on COW instead
3034 * of the full address range.
3036 if (is_vma_resv_set(vma
, HPAGE_RESV_OWNER
) &&
3037 old_page
!= pagecache_page
)
3038 outside_reserve
= 1;
3040 page_cache_get(old_page
);
3043 * Drop page table lock as buddy allocator may be called. It will
3044 * be acquired again before returning to the caller, as expected.
3047 new_page
= alloc_huge_page(vma
, address
, outside_reserve
);
3049 if (IS_ERR(new_page
)) {
3051 * If a process owning a MAP_PRIVATE mapping fails to COW,
3052 * it is due to references held by a child and an insufficient
3053 * huge page pool. To guarantee the original mappers
3054 * reliability, unmap the page from child processes. The child
3055 * may get SIGKILLed if it later faults.
3057 if (outside_reserve
) {
3058 page_cache_release(old_page
);
3059 BUG_ON(huge_pte_none(pte
));
3060 unmap_ref_private(mm
, vma
, old_page
, address
);
3061 BUG_ON(huge_pte_none(pte
));
3063 ptep
= huge_pte_offset(mm
, address
& huge_page_mask(h
));
3065 pte_same(huge_ptep_get(ptep
), pte
)))
3066 goto retry_avoidcopy
;
3068 * race occurs while re-acquiring page table
3069 * lock, and our job is done.
3074 ret
= (PTR_ERR(new_page
) == -ENOMEM
) ?
3075 VM_FAULT_OOM
: VM_FAULT_SIGBUS
;
3076 goto out_release_old
;
3080 * When the original hugepage is shared one, it does not have
3081 * anon_vma prepared.
3083 if (unlikely(anon_vma_prepare(vma
))) {
3085 goto out_release_all
;
3088 copy_user_huge_page(new_page
, old_page
, address
, vma
,
3089 pages_per_huge_page(h
));
3090 __SetPageUptodate(new_page
);
3091 set_page_huge_active(new_page
);
3093 mmun_start
= address
& huge_page_mask(h
);
3094 mmun_end
= mmun_start
+ huge_page_size(h
);
3095 mmu_notifier_invalidate_range_start(mm
, mmun_start
, mmun_end
);
3098 * Retake the page table lock to check for racing updates
3099 * before the page tables are altered
3102 ptep
= huge_pte_offset(mm
, address
& huge_page_mask(h
));
3103 if (likely(ptep
&& pte_same(huge_ptep_get(ptep
), pte
))) {
3104 ClearPagePrivate(new_page
);
3107 huge_ptep_clear_flush(vma
, address
, ptep
);
3108 mmu_notifier_invalidate_range(mm
, mmun_start
, mmun_end
);
3109 set_huge_pte_at(mm
, address
, ptep
,
3110 make_huge_pte(vma
, new_page
, 1));
3111 page_remove_rmap(old_page
);
3112 hugepage_add_new_anon_rmap(new_page
, vma
, address
);
3113 /* Make the old page be freed below */
3114 new_page
= old_page
;
3117 mmu_notifier_invalidate_range_end(mm
, mmun_start
, mmun_end
);
3119 page_cache_release(new_page
);
3121 page_cache_release(old_page
);
3123 spin_lock(ptl
); /* Caller expects lock to be held */
3127 /* Return the pagecache page at a given address within a VMA */
3128 static struct page
*hugetlbfs_pagecache_page(struct hstate
*h
,
3129 struct vm_area_struct
*vma
, unsigned long address
)
3131 struct address_space
*mapping
;
3134 mapping
= vma
->vm_file
->f_mapping
;
3135 idx
= vma_hugecache_offset(h
, vma
, address
);
3137 return find_lock_page(mapping
, idx
);
3141 * Return whether there is a pagecache page to back given address within VMA.
3142 * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page.
3144 static bool hugetlbfs_pagecache_present(struct hstate
*h
,
3145 struct vm_area_struct
*vma
, unsigned long address
)
3147 struct address_space
*mapping
;
3151 mapping
= vma
->vm_file
->f_mapping
;
3152 idx
= vma_hugecache_offset(h
, vma
, address
);
3154 page
= find_get_page(mapping
, idx
);
3157 return page
!= NULL
;
3160 static int hugetlb_no_page(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
3161 struct address_space
*mapping
, pgoff_t idx
,
3162 unsigned long address
, pte_t
*ptep
, unsigned int flags
)
3164 struct hstate
*h
= hstate_vma(vma
);
3165 int ret
= VM_FAULT_SIGBUS
;
3173 * Currently, we are forced to kill the process in the event the
3174 * original mapper has unmapped pages from the child due to a failed
3175 * COW. Warn that such a situation has occurred as it may not be obvious
3177 if (is_vma_resv_set(vma
, HPAGE_RESV_UNMAPPED
)) {
3178 pr_warning("PID %d killed due to inadequate hugepage pool\n",
3184 * Use page lock to guard against racing truncation
3185 * before we get page_table_lock.
3188 page
= find_lock_page(mapping
, idx
);
3190 size
= i_size_read(mapping
->host
) >> huge_page_shift(h
);
3193 page
= alloc_huge_page(vma
, address
, 0);
3195 ret
= PTR_ERR(page
);
3199 ret
= VM_FAULT_SIGBUS
;
3202 clear_huge_page(page
, address
, pages_per_huge_page(h
));
3203 __SetPageUptodate(page
);
3204 set_page_huge_active(page
);
3206 if (vma
->vm_flags
& VM_MAYSHARE
) {
3208 struct inode
*inode
= mapping
->host
;
3210 err
= add_to_page_cache(page
, mapping
, idx
, GFP_KERNEL
);
3217 ClearPagePrivate(page
);
3219 spin_lock(&inode
->i_lock
);
3220 inode
->i_blocks
+= blocks_per_huge_page(h
);
3221 spin_unlock(&inode
->i_lock
);
3224 if (unlikely(anon_vma_prepare(vma
))) {
3226 goto backout_unlocked
;
3232 * If memory error occurs between mmap() and fault, some process
3233 * don't have hwpoisoned swap entry for errored virtual address.
3234 * So we need to block hugepage fault by PG_hwpoison bit check.
3236 if (unlikely(PageHWPoison(page
))) {
3237 ret
= VM_FAULT_HWPOISON
|
3238 VM_FAULT_SET_HINDEX(hstate_index(h
));
3239 goto backout_unlocked
;
3244 * If we are going to COW a private mapping later, we examine the
3245 * pending reservations for this page now. This will ensure that
3246 * any allocations necessary to record that reservation occur outside
3249 if ((flags
& FAULT_FLAG_WRITE
) && !(vma
->vm_flags
& VM_SHARED
))
3250 if (vma_needs_reservation(h
, vma
, address
) < 0) {
3252 goto backout_unlocked
;
3255 ptl
= huge_pte_lockptr(h
, mm
, ptep
);
3257 size
= i_size_read(mapping
->host
) >> huge_page_shift(h
);
3262 if (!huge_pte_none(huge_ptep_get(ptep
)))
3266 ClearPagePrivate(page
);
3267 hugepage_add_new_anon_rmap(page
, vma
, address
);
3269 page_dup_rmap(page
);
3270 new_pte
= make_huge_pte(vma
, page
, ((vma
->vm_flags
& VM_WRITE
)
3271 && (vma
->vm_flags
& VM_SHARED
)));
3272 set_huge_pte_at(mm
, address
, ptep
, new_pte
);
3274 if ((flags
& FAULT_FLAG_WRITE
) && !(vma
->vm_flags
& VM_SHARED
)) {
3275 /* Optimization, do the COW without a second fault */
3276 ret
= hugetlb_cow(mm
, vma
, address
, ptep
, new_pte
, page
, ptl
);
3293 static u32
fault_mutex_hash(struct hstate
*h
, struct mm_struct
*mm
,
3294 struct vm_area_struct
*vma
,
3295 struct address_space
*mapping
,
3296 pgoff_t idx
, unsigned long address
)
3298 unsigned long key
[2];
3301 if (vma
->vm_flags
& VM_SHARED
) {
3302 key
[0] = (unsigned long) mapping
;
3305 key
[0] = (unsigned long) mm
;
3306 key
[1] = address
>> huge_page_shift(h
);
3309 hash
= jhash2((u32
*)&key
, sizeof(key
)/sizeof(u32
), 0);
3311 return hash
& (num_fault_mutexes
- 1);
3315 * For uniprocesor systems we always use a single mutex, so just
3316 * return 0 and avoid the hashing overhead.
3318 static u32
fault_mutex_hash(struct hstate
*h
, struct mm_struct
*mm
,
3319 struct vm_area_struct
*vma
,
3320 struct address_space
*mapping
,
3321 pgoff_t idx
, unsigned long address
)
3327 int hugetlb_fault(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
3328 unsigned long address
, unsigned int flags
)
3335 struct page
*page
= NULL
;
3336 struct page
*pagecache_page
= NULL
;
3337 struct hstate
*h
= hstate_vma(vma
);
3338 struct address_space
*mapping
;
3339 int need_wait_lock
= 0;
3341 address
&= huge_page_mask(h
);
3343 ptep
= huge_pte_offset(mm
, address
);
3345 entry
= huge_ptep_get(ptep
);
3346 if (unlikely(is_hugetlb_entry_migration(entry
))) {
3347 migration_entry_wait_huge(vma
, mm
, ptep
);
3349 } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry
)))
3350 return VM_FAULT_HWPOISON_LARGE
|
3351 VM_FAULT_SET_HINDEX(hstate_index(h
));
3354 ptep
= huge_pte_alloc(mm
, address
, huge_page_size(h
));
3356 return VM_FAULT_OOM
;
3358 mapping
= vma
->vm_file
->f_mapping
;
3359 idx
= vma_hugecache_offset(h
, vma
, address
);
3362 * Serialize hugepage allocation and instantiation, so that we don't
3363 * get spurious allocation failures if two CPUs race to instantiate
3364 * the same page in the page cache.
3366 hash
= fault_mutex_hash(h
, mm
, vma
, mapping
, idx
, address
);
3367 mutex_lock(&htlb_fault_mutex_table
[hash
]);
3369 entry
= huge_ptep_get(ptep
);
3370 if (huge_pte_none(entry
)) {
3371 ret
= hugetlb_no_page(mm
, vma
, mapping
, idx
, address
, ptep
, flags
);
3378 * entry could be a migration/hwpoison entry at this point, so this
3379 * check prevents the kernel from going below assuming that we have
3380 * a active hugepage in pagecache. This goto expects the 2nd page fault,
3381 * and is_hugetlb_entry_(migration|hwpoisoned) check will properly
3384 if (!pte_present(entry
))
3388 * If we are going to COW the mapping later, we examine the pending
3389 * reservations for this page now. This will ensure that any
3390 * allocations necessary to record that reservation occur outside the
3391 * spinlock. For private mappings, we also lookup the pagecache
3392 * page now as it is used to determine if a reservation has been
3395 if ((flags
& FAULT_FLAG_WRITE
) && !huge_pte_write(entry
)) {
3396 if (vma_needs_reservation(h
, vma
, address
) < 0) {
3401 if (!(vma
->vm_flags
& VM_MAYSHARE
))
3402 pagecache_page
= hugetlbfs_pagecache_page(h
,
3406 ptl
= huge_pte_lock(h
, mm
, ptep
);
3408 /* Check for a racing update before calling hugetlb_cow */
3409 if (unlikely(!pte_same(entry
, huge_ptep_get(ptep
))))
3413 * hugetlb_cow() requires page locks of pte_page(entry) and
3414 * pagecache_page, so here we need take the former one
3415 * when page != pagecache_page or !pagecache_page.
3417 page
= pte_page(entry
);
3418 if (page
!= pagecache_page
)
3419 if (!trylock_page(page
)) {
3426 if (flags
& FAULT_FLAG_WRITE
) {
3427 if (!huge_pte_write(entry
)) {
3428 ret
= hugetlb_cow(mm
, vma
, address
, ptep
, entry
,
3429 pagecache_page
, ptl
);
3432 entry
= huge_pte_mkdirty(entry
);
3434 entry
= pte_mkyoung(entry
);
3435 if (huge_ptep_set_access_flags(vma
, address
, ptep
, entry
,
3436 flags
& FAULT_FLAG_WRITE
))
3437 update_mmu_cache(vma
, address
, ptep
);
3439 if (page
!= pagecache_page
)
3445 if (pagecache_page
) {
3446 unlock_page(pagecache_page
);
3447 put_page(pagecache_page
);
3450 mutex_unlock(&htlb_fault_mutex_table
[hash
]);
3452 * Generally it's safe to hold refcount during waiting page lock. But
3453 * here we just wait to defer the next page fault to avoid busy loop and
3454 * the page is not used after unlocked before returning from the current
3455 * page fault. So we are safe from accessing freed page, even if we wait
3456 * here without taking refcount.
3459 wait_on_page_locked(page
);
3463 long follow_hugetlb_page(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
3464 struct page
**pages
, struct vm_area_struct
**vmas
,
3465 unsigned long *position
, unsigned long *nr_pages
,
3466 long i
, unsigned int flags
)
3468 unsigned long pfn_offset
;
3469 unsigned long vaddr
= *position
;
3470 unsigned long remainder
= *nr_pages
;
3471 struct hstate
*h
= hstate_vma(vma
);
3473 while (vaddr
< vma
->vm_end
&& remainder
) {
3475 spinlock_t
*ptl
= NULL
;
3480 * If we have a pending SIGKILL, don't keep faulting pages and
3481 * potentially allocating memory.
3483 if (unlikely(fatal_signal_pending(current
))) {
3489 * Some archs (sparc64, sh*) have multiple pte_ts to
3490 * each hugepage. We have to make sure we get the
3491 * first, for the page indexing below to work.
3493 * Note that page table lock is not held when pte is null.
3495 pte
= huge_pte_offset(mm
, vaddr
& huge_page_mask(h
));
3497 ptl
= huge_pte_lock(h
, mm
, pte
);
3498 absent
= !pte
|| huge_pte_none(huge_ptep_get(pte
));
3501 * When coredumping, it suits get_dump_page if we just return
3502 * an error where there's an empty slot with no huge pagecache
3503 * to back it. This way, we avoid allocating a hugepage, and
3504 * the sparse dumpfile avoids allocating disk blocks, but its
3505 * huge holes still show up with zeroes where they need to be.
3507 if (absent
&& (flags
& FOLL_DUMP
) &&
3508 !hugetlbfs_pagecache_present(h
, vma
, vaddr
)) {
3516 * We need call hugetlb_fault for both hugepages under migration
3517 * (in which case hugetlb_fault waits for the migration,) and
3518 * hwpoisoned hugepages (in which case we need to prevent the
3519 * caller from accessing to them.) In order to do this, we use
3520 * here is_swap_pte instead of is_hugetlb_entry_migration and
3521 * is_hugetlb_entry_hwpoisoned. This is because it simply covers
3522 * both cases, and because we can't follow correct pages
3523 * directly from any kind of swap entries.
3525 if (absent
|| is_swap_pte(huge_ptep_get(pte
)) ||
3526 ((flags
& FOLL_WRITE
) &&
3527 !huge_pte_write(huge_ptep_get(pte
)))) {
3532 ret
= hugetlb_fault(mm
, vma
, vaddr
,
3533 (flags
& FOLL_WRITE
) ? FAULT_FLAG_WRITE
: 0);
3534 if (!(ret
& VM_FAULT_ERROR
))
3541 pfn_offset
= (vaddr
& ~huge_page_mask(h
)) >> PAGE_SHIFT
;
3542 page
= pte_page(huge_ptep_get(pte
));
3545 pages
[i
] = mem_map_offset(page
, pfn_offset
);
3546 get_page_foll(pages
[i
]);
3556 if (vaddr
< vma
->vm_end
&& remainder
&&
3557 pfn_offset
< pages_per_huge_page(h
)) {
3559 * We use pfn_offset to avoid touching the pageframes
3560 * of this compound page.
3566 *nr_pages
= remainder
;
3569 return i
? i
: -EFAULT
;
3572 unsigned long hugetlb_change_protection(struct vm_area_struct
*vma
,
3573 unsigned long address
, unsigned long end
, pgprot_t newprot
)
3575 struct mm_struct
*mm
= vma
->vm_mm
;
3576 unsigned long start
= address
;
3579 struct hstate
*h
= hstate_vma(vma
);
3580 unsigned long pages
= 0;
3582 BUG_ON(address
>= end
);
3583 flush_cache_range(vma
, address
, end
);
3585 mmu_notifier_invalidate_range_start(mm
, start
, end
);
3586 i_mmap_lock_write(vma
->vm_file
->f_mapping
);
3587 for (; address
< end
; address
+= huge_page_size(h
)) {
3589 ptep
= huge_pte_offset(mm
, address
);
3592 ptl
= huge_pte_lock(h
, mm
, ptep
);
3593 if (huge_pmd_unshare(mm
, &address
, ptep
)) {
3598 pte
= huge_ptep_get(ptep
);
3599 if (unlikely(is_hugetlb_entry_hwpoisoned(pte
))) {
3603 if (unlikely(is_hugetlb_entry_migration(pte
))) {
3604 swp_entry_t entry
= pte_to_swp_entry(pte
);
3606 if (is_write_migration_entry(entry
)) {
3609 make_migration_entry_read(&entry
);
3610 newpte
= swp_entry_to_pte(entry
);
3611 set_huge_pte_at(mm
, address
, ptep
, newpte
);
3617 if (!huge_pte_none(pte
)) {
3618 pte
= huge_ptep_get_and_clear(mm
, address
, ptep
);
3619 pte
= pte_mkhuge(huge_pte_modify(pte
, newprot
));
3620 pte
= arch_make_huge_pte(pte
, vma
, NULL
, 0);
3621 set_huge_pte_at(mm
, address
, ptep
, pte
);
3627 * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare
3628 * may have cleared our pud entry and done put_page on the page table:
3629 * once we release i_mmap_rwsem, another task can do the final put_page
3630 * and that page table be reused and filled with junk.
3632 flush_tlb_range(vma
, start
, end
);
3633 mmu_notifier_invalidate_range(mm
, start
, end
);
3634 i_mmap_unlock_write(vma
->vm_file
->f_mapping
);
3635 mmu_notifier_invalidate_range_end(mm
, start
, end
);
3637 return pages
<< h
->order
;
3640 int hugetlb_reserve_pages(struct inode
*inode
,
3642 struct vm_area_struct
*vma
,
3643 vm_flags_t vm_flags
)
3646 struct hstate
*h
= hstate_inode(inode
);
3647 struct hugepage_subpool
*spool
= subpool_inode(inode
);
3648 struct resv_map
*resv_map
;
3652 * Only apply hugepage reservation if asked. At fault time, an
3653 * attempt will be made for VM_NORESERVE to allocate a page
3654 * without using reserves
3656 if (vm_flags
& VM_NORESERVE
)
3660 * Shared mappings base their reservation on the number of pages that
3661 * are already allocated on behalf of the file. Private mappings need
3662 * to reserve the full area even if read-only as mprotect() may be
3663 * called to make the mapping read-write. Assume !vma is a shm mapping
3665 if (!vma
|| vma
->vm_flags
& VM_MAYSHARE
) {
3666 resv_map
= inode_resv_map(inode
);
3668 chg
= region_chg(resv_map
, from
, to
);
3671 resv_map
= resv_map_alloc();
3677 set_vma_resv_map(vma
, resv_map
);
3678 set_vma_resv_flags(vma
, HPAGE_RESV_OWNER
);
3687 * There must be enough pages in the subpool for the mapping. If
3688 * the subpool has a minimum size, there may be some global
3689 * reservations already in place (gbl_reserve).
3691 gbl_reserve
= hugepage_subpool_get_pages(spool
, chg
);
3692 if (gbl_reserve
< 0) {
3698 * Check enough hugepages are available for the reservation.
3699 * Hand the pages back to the subpool if there are not
3701 ret
= hugetlb_acct_memory(h
, gbl_reserve
);
3703 /* put back original number of pages, chg */
3704 (void)hugepage_subpool_put_pages(spool
, chg
);
3709 * Account for the reservations made. Shared mappings record regions
3710 * that have reservations as they are shared by multiple VMAs.
3711 * When the last VMA disappears, the region map says how much
3712 * the reservation was and the page cache tells how much of
3713 * the reservation was consumed. Private mappings are per-VMA and
3714 * only the consumed reservations are tracked. When the VMA
3715 * disappears, the original reservation is the VMA size and the
3716 * consumed reservations are stored in the map. Hence, nothing
3717 * else has to be done for private mappings here
3719 if (!vma
|| vma
->vm_flags
& VM_MAYSHARE
) {
3720 long add
= region_add(resv_map
, from
, to
);
3722 if (unlikely(chg
> add
)) {
3724 * pages in this range were added to the reserve
3725 * map between region_chg and region_add. This
3726 * indicates a race with alloc_huge_page. Adjust
3727 * the subpool and reserve counts modified above
3728 * based on the difference.
3732 rsv_adjust
= hugepage_subpool_put_pages(spool
,
3734 hugetlb_acct_memory(h
, -rsv_adjust
);
3739 if (vma
&& is_vma_resv_set(vma
, HPAGE_RESV_OWNER
))
3740 kref_put(&resv_map
->refs
, resv_map_release
);
3744 void hugetlb_unreserve_pages(struct inode
*inode
, long offset
, long freed
)
3746 struct hstate
*h
= hstate_inode(inode
);
3747 struct resv_map
*resv_map
= inode_resv_map(inode
);
3749 struct hugepage_subpool
*spool
= subpool_inode(inode
);
3753 chg
= region_truncate(resv_map
, offset
);
3754 spin_lock(&inode
->i_lock
);
3755 inode
->i_blocks
-= (blocks_per_huge_page(h
) * freed
);
3756 spin_unlock(&inode
->i_lock
);
3759 * If the subpool has a minimum size, the number of global
3760 * reservations to be released may be adjusted.
3762 gbl_reserve
= hugepage_subpool_put_pages(spool
, (chg
- freed
));
3763 hugetlb_acct_memory(h
, -gbl_reserve
);
3766 #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
3767 static unsigned long page_table_shareable(struct vm_area_struct
*svma
,
3768 struct vm_area_struct
*vma
,
3769 unsigned long addr
, pgoff_t idx
)
3771 unsigned long saddr
= ((idx
- svma
->vm_pgoff
) << PAGE_SHIFT
) +
3773 unsigned long sbase
= saddr
& PUD_MASK
;
3774 unsigned long s_end
= sbase
+ PUD_SIZE
;
3776 /* Allow segments to share if only one is marked locked */
3777 unsigned long vm_flags
= vma
->vm_flags
& ~VM_LOCKED
;
3778 unsigned long svm_flags
= svma
->vm_flags
& ~VM_LOCKED
;
3781 * match the virtual addresses, permission and the alignment of the
3784 if (pmd_index(addr
) != pmd_index(saddr
) ||
3785 vm_flags
!= svm_flags
||
3786 sbase
< svma
->vm_start
|| svma
->vm_end
< s_end
)
3792 static int vma_shareable(struct vm_area_struct
*vma
, unsigned long addr
)
3794 unsigned long base
= addr
& PUD_MASK
;
3795 unsigned long end
= base
+ PUD_SIZE
;
3798 * check on proper vm_flags and page table alignment
3800 if (vma
->vm_flags
& VM_MAYSHARE
&&
3801 vma
->vm_start
<= base
&& end
<= vma
->vm_end
)
3807 * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc()
3808 * and returns the corresponding pte. While this is not necessary for the
3809 * !shared pmd case because we can allocate the pmd later as well, it makes the
3810 * code much cleaner. pmd allocation is essential for the shared case because
3811 * pud has to be populated inside the same i_mmap_rwsem section - otherwise
3812 * racing tasks could either miss the sharing (see huge_pte_offset) or select a
3813 * bad pmd for sharing.
3815 pte_t
*huge_pmd_share(struct mm_struct
*mm
, unsigned long addr
, pud_t
*pud
)
3817 struct vm_area_struct
*vma
= find_vma(mm
, addr
);
3818 struct address_space
*mapping
= vma
->vm_file
->f_mapping
;
3819 pgoff_t idx
= ((addr
- vma
->vm_start
) >> PAGE_SHIFT
) +
3821 struct vm_area_struct
*svma
;
3822 unsigned long saddr
;
3827 if (!vma_shareable(vma
, addr
))
3828 return (pte_t
*)pmd_alloc(mm
, pud
, addr
);
3830 i_mmap_lock_write(mapping
);
3831 vma_interval_tree_foreach(svma
, &mapping
->i_mmap
, idx
, idx
) {
3835 saddr
= page_table_shareable(svma
, vma
, addr
, idx
);
3837 spte
= huge_pte_offset(svma
->vm_mm
, saddr
);
3840 get_page(virt_to_page(spte
));
3849 ptl
= huge_pte_lockptr(hstate_vma(vma
), mm
, spte
);
3851 if (pud_none(*pud
)) {
3852 pud_populate(mm
, pud
,
3853 (pmd_t
*)((unsigned long)spte
& PAGE_MASK
));
3855 put_page(virt_to_page(spte
));
3860 pte
= (pte_t
*)pmd_alloc(mm
, pud
, addr
);
3861 i_mmap_unlock_write(mapping
);
3866 * unmap huge page backed by shared pte.
3868 * Hugetlb pte page is ref counted at the time of mapping. If pte is shared
3869 * indicated by page_count > 1, unmap is achieved by clearing pud and
3870 * decrementing the ref count. If count == 1, the pte page is not shared.
3872 * called with page table lock held.
3874 * returns: 1 successfully unmapped a shared pte page
3875 * 0 the underlying pte page is not shared, or it is the last user
3877 int huge_pmd_unshare(struct mm_struct
*mm
, unsigned long *addr
, pte_t
*ptep
)
3879 pgd_t
*pgd
= pgd_offset(mm
, *addr
);
3880 pud_t
*pud
= pud_offset(pgd
, *addr
);
3882 BUG_ON(page_count(virt_to_page(ptep
)) == 0);
3883 if (page_count(virt_to_page(ptep
)) == 1)
3887 put_page(virt_to_page(ptep
));
3889 *addr
= ALIGN(*addr
, HPAGE_SIZE
* PTRS_PER_PTE
) - HPAGE_SIZE
;
3892 #define want_pmd_share() (1)
3893 #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
3894 pte_t
*huge_pmd_share(struct mm_struct
*mm
, unsigned long addr
, pud_t
*pud
)
3899 int huge_pmd_unshare(struct mm_struct
*mm
, unsigned long *addr
, pte_t
*ptep
)
3903 #define want_pmd_share() (0)
3904 #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
3906 #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
3907 pte_t
*huge_pte_alloc(struct mm_struct
*mm
,
3908 unsigned long addr
, unsigned long sz
)
3914 pgd
= pgd_offset(mm
, addr
);
3915 pud
= pud_alloc(mm
, pgd
, addr
);
3917 if (sz
== PUD_SIZE
) {
3920 BUG_ON(sz
!= PMD_SIZE
);
3921 if (want_pmd_share() && pud_none(*pud
))
3922 pte
= huge_pmd_share(mm
, addr
, pud
);
3924 pte
= (pte_t
*)pmd_alloc(mm
, pud
, addr
);
3927 BUG_ON(pte
&& !pte_none(*pte
) && !pte_huge(*pte
));
3932 pte_t
*huge_pte_offset(struct mm_struct
*mm
, unsigned long addr
)
3938 pgd
= pgd_offset(mm
, addr
);
3939 if (pgd_present(*pgd
)) {
3940 pud
= pud_offset(pgd
, addr
);
3941 if (pud_present(*pud
)) {
3943 return (pte_t
*)pud
;
3944 pmd
= pmd_offset(pud
, addr
);
3947 return (pte_t
*) pmd
;
3950 #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
3953 * These functions are overwritable if your architecture needs its own
3956 struct page
* __weak
3957 follow_huge_addr(struct mm_struct
*mm
, unsigned long address
,
3960 return ERR_PTR(-EINVAL
);
3963 struct page
* __weak
3964 follow_huge_pmd(struct mm_struct
*mm
, unsigned long address
,
3965 pmd_t
*pmd
, int flags
)
3967 struct page
*page
= NULL
;
3970 ptl
= pmd_lockptr(mm
, pmd
);
3973 * make sure that the address range covered by this pmd is not
3974 * unmapped from other threads.
3976 if (!pmd_huge(*pmd
))
3978 if (pmd_present(*pmd
)) {
3979 page
= pmd_page(*pmd
) + ((address
& ~PMD_MASK
) >> PAGE_SHIFT
);
3980 if (flags
& FOLL_GET
)
3983 if (is_hugetlb_entry_migration(huge_ptep_get((pte_t
*)pmd
))) {
3985 __migration_entry_wait(mm
, (pte_t
*)pmd
, ptl
);
3989 * hwpoisoned entry is treated as no_page_table in
3990 * follow_page_mask().
3998 struct page
* __weak
3999 follow_huge_pud(struct mm_struct
*mm
, unsigned long address
,
4000 pud_t
*pud
, int flags
)
4002 if (flags
& FOLL_GET
)
4005 return pte_page(*(pte_t
*)pud
) + ((address
& ~PUD_MASK
) >> PAGE_SHIFT
);
4008 #ifdef CONFIG_MEMORY_FAILURE
4011 * This function is called from memory failure code.
4012 * Assume the caller holds page lock of the head page.
4014 int dequeue_hwpoisoned_huge_page(struct page
*hpage
)
4016 struct hstate
*h
= page_hstate(hpage
);
4017 int nid
= page_to_nid(hpage
);
4020 spin_lock(&hugetlb_lock
);
4022 * Just checking !page_huge_active is not enough, because that could be
4023 * an isolated/hwpoisoned hugepage (which have >0 refcount).
4025 if (!page_huge_active(hpage
) && !page_count(hpage
)) {
4027 * Hwpoisoned hugepage isn't linked to activelist or freelist,
4028 * but dangling hpage->lru can trigger list-debug warnings
4029 * (this happens when we call unpoison_memory() on it),
4030 * so let it point to itself with list_del_init().
4032 list_del_init(&hpage
->lru
);
4033 set_page_refcounted(hpage
);
4034 h
->free_huge_pages
--;
4035 h
->free_huge_pages_node
[nid
]--;
4038 spin_unlock(&hugetlb_lock
);
4043 bool isolate_huge_page(struct page
*page
, struct list_head
*list
)
4047 VM_BUG_ON_PAGE(!PageHead(page
), page
);
4048 spin_lock(&hugetlb_lock
);
4049 if (!page_huge_active(page
) || !get_page_unless_zero(page
)) {
4053 clear_page_huge_active(page
);
4054 list_move_tail(&page
->lru
, list
);
4056 spin_unlock(&hugetlb_lock
);
4060 void putback_active_hugepage(struct page
*page
)
4062 VM_BUG_ON_PAGE(!PageHead(page
), page
);
4063 spin_lock(&hugetlb_lock
);
4064 set_page_huge_active(page
);
4065 list_move_tail(&page
->lru
, &(page_hstate(page
))->hugepage_activelist
);
4066 spin_unlock(&hugetlb_lock
);