1 // SPDX-License-Identifier: GPL-2.0-only
3 * Generic hugetlb support.
4 * (C) Nadia Yvette Chambers, April 2004
6 #include <linux/list.h>
7 #include <linux/init.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/memblock.h>
20 #include <linux/sysfs.h>
21 #include <linux/slab.h>
22 #include <linux/sched/mm.h>
23 #include <linux/mmdebug.h>
24 #include <linux/sched/signal.h>
25 #include <linux/rmap.h>
26 #include <linux/string_helpers.h>
27 #include <linux/swap.h>
28 #include <linux/swapops.h>
29 #include <linux/jhash.h>
30 #include <linux/numa.h>
31 #include <linux/llist.h>
32 #include <linux/cma.h>
33 #include <linux/migrate.h>
36 #include <asm/pgalloc.h>
40 #include <linux/hugetlb.h>
41 #include <linux/hugetlb_cgroup.h>
42 #include <linux/node.h>
43 #include <linux/page_owner.h>
45 #include "hugetlb_vmemmap.h"
47 int hugetlb_max_hstate __read_mostly
;
48 unsigned int default_hstate_idx
;
49 struct hstate hstates
[HUGE_MAX_HSTATE
];
52 static struct cma
*hugetlb_cma
[MAX_NUMNODES
];
54 static unsigned long hugetlb_cma_size __initdata
;
57 * Minimum page order among possible hugepage sizes, set to a proper value
60 static unsigned int minimum_order __read_mostly
= UINT_MAX
;
62 __initdata
LIST_HEAD(huge_boot_pages
);
64 /* for command line parsing */
65 static struct hstate
* __initdata parsed_hstate
;
66 static unsigned long __initdata default_hstate_max_huge_pages
;
67 static bool __initdata parsed_valid_hugepagesz
= true;
68 static bool __initdata parsed_default_hugepagesz
;
71 * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages,
72 * free_huge_pages, and surplus_huge_pages.
74 DEFINE_SPINLOCK(hugetlb_lock
);
77 * Serializes faults on the same logical page. This is used to
78 * prevent spurious OOMs when the hugepage pool is fully utilized.
80 static int num_fault_mutexes
;
81 struct mutex
*hugetlb_fault_mutex_table ____cacheline_aligned_in_smp
;
83 /* Forward declaration */
84 static int hugetlb_acct_memory(struct hstate
*h
, long delta
);
86 static inline bool subpool_is_free(struct hugepage_subpool
*spool
)
90 if (spool
->max_hpages
!= -1)
91 return spool
->used_hpages
== 0;
92 if (spool
->min_hpages
!= -1)
93 return spool
->rsv_hpages
== spool
->min_hpages
;
98 static inline void unlock_or_release_subpool(struct hugepage_subpool
*spool
,
99 unsigned long irq_flags
)
101 spin_unlock_irqrestore(&spool
->lock
, irq_flags
);
103 /* If no pages are used, and no other handles to the subpool
104 * remain, give up any reservations based on minimum size and
105 * free the subpool */
106 if (subpool_is_free(spool
)) {
107 if (spool
->min_hpages
!= -1)
108 hugetlb_acct_memory(spool
->hstate
,
114 struct hugepage_subpool
*hugepage_new_subpool(struct hstate
*h
, long max_hpages
,
117 struct hugepage_subpool
*spool
;
119 spool
= kzalloc(sizeof(*spool
), GFP_KERNEL
);
123 spin_lock_init(&spool
->lock
);
125 spool
->max_hpages
= max_hpages
;
127 spool
->min_hpages
= min_hpages
;
129 if (min_hpages
!= -1 && hugetlb_acct_memory(h
, min_hpages
)) {
133 spool
->rsv_hpages
= min_hpages
;
138 void hugepage_put_subpool(struct hugepage_subpool
*spool
)
142 spin_lock_irqsave(&spool
->lock
, flags
);
143 BUG_ON(!spool
->count
);
145 unlock_or_release_subpool(spool
, flags
);
149 * Subpool accounting for allocating and reserving pages.
150 * Return -ENOMEM if there are not enough resources to satisfy the
151 * request. Otherwise, return the number of pages by which the
152 * global pools must be adjusted (upward). The returned value may
153 * only be different than the passed value (delta) in the case where
154 * a subpool minimum size must be maintained.
156 static long hugepage_subpool_get_pages(struct hugepage_subpool
*spool
,
164 spin_lock_irq(&spool
->lock
);
166 if (spool
->max_hpages
!= -1) { /* maximum size accounting */
167 if ((spool
->used_hpages
+ delta
) <= spool
->max_hpages
)
168 spool
->used_hpages
+= delta
;
175 /* minimum size accounting */
176 if (spool
->min_hpages
!= -1 && spool
->rsv_hpages
) {
177 if (delta
> spool
->rsv_hpages
) {
179 * Asking for more reserves than those already taken on
180 * behalf of subpool. Return difference.
182 ret
= delta
- spool
->rsv_hpages
;
183 spool
->rsv_hpages
= 0;
185 ret
= 0; /* reserves already accounted for */
186 spool
->rsv_hpages
-= delta
;
191 spin_unlock_irq(&spool
->lock
);
196 * Subpool accounting for freeing and unreserving pages.
197 * Return the number of global page reservations that must be dropped.
198 * The return value may only be different than the passed value (delta)
199 * in the case where a subpool minimum size must be maintained.
201 static long hugepage_subpool_put_pages(struct hugepage_subpool
*spool
,
210 spin_lock_irqsave(&spool
->lock
, flags
);
212 if (spool
->max_hpages
!= -1) /* maximum size accounting */
213 spool
->used_hpages
-= delta
;
215 /* minimum size accounting */
216 if (spool
->min_hpages
!= -1 && spool
->used_hpages
< spool
->min_hpages
) {
217 if (spool
->rsv_hpages
+ delta
<= spool
->min_hpages
)
220 ret
= spool
->rsv_hpages
+ delta
- spool
->min_hpages
;
222 spool
->rsv_hpages
+= delta
;
223 if (spool
->rsv_hpages
> spool
->min_hpages
)
224 spool
->rsv_hpages
= spool
->min_hpages
;
228 * If hugetlbfs_put_super couldn't free spool due to an outstanding
229 * quota reference, free it now.
231 unlock_or_release_subpool(spool
, flags
);
236 static inline struct hugepage_subpool
*subpool_inode(struct inode
*inode
)
238 return HUGETLBFS_SB(inode
->i_sb
)->spool
;
241 static inline struct hugepage_subpool
*subpool_vma(struct vm_area_struct
*vma
)
243 return subpool_inode(file_inode(vma
->vm_file
));
246 /* Helper that removes a struct file_region from the resv_map cache and returns
249 static struct file_region
*
250 get_file_region_entry_from_cache(struct resv_map
*resv
, long from
, long to
)
252 struct file_region
*nrg
= NULL
;
254 VM_BUG_ON(resv
->region_cache_count
<= 0);
256 resv
->region_cache_count
--;
257 nrg
= list_first_entry(&resv
->region_cache
, struct file_region
, link
);
258 list_del(&nrg
->link
);
266 static void copy_hugetlb_cgroup_uncharge_info(struct file_region
*nrg
,
267 struct file_region
*rg
)
269 #ifdef CONFIG_CGROUP_HUGETLB
270 nrg
->reservation_counter
= rg
->reservation_counter
;
277 /* Helper that records hugetlb_cgroup uncharge info. */
278 static void record_hugetlb_cgroup_uncharge_info(struct hugetlb_cgroup
*h_cg
,
280 struct resv_map
*resv
,
281 struct file_region
*nrg
)
283 #ifdef CONFIG_CGROUP_HUGETLB
285 nrg
->reservation_counter
=
286 &h_cg
->rsvd_hugepage
[hstate_index(h
)];
287 nrg
->css
= &h_cg
->css
;
289 * The caller will hold exactly one h_cg->css reference for the
290 * whole contiguous reservation region. But this area might be
291 * scattered when there are already some file_regions reside in
292 * it. As a result, many file_regions may share only one css
293 * reference. In order to ensure that one file_region must hold
294 * exactly one h_cg->css reference, we should do css_get for
295 * each file_region and leave the reference held by caller
299 if (!resv
->pages_per_hpage
)
300 resv
->pages_per_hpage
= pages_per_huge_page(h
);
301 /* pages_per_hpage should be the same for all entries in
304 VM_BUG_ON(resv
->pages_per_hpage
!= pages_per_huge_page(h
));
306 nrg
->reservation_counter
= NULL
;
312 static void put_uncharge_info(struct file_region
*rg
)
314 #ifdef CONFIG_CGROUP_HUGETLB
320 static bool has_same_uncharge_info(struct file_region
*rg
,
321 struct file_region
*org
)
323 #ifdef CONFIG_CGROUP_HUGETLB
325 rg
->reservation_counter
== org
->reservation_counter
&&
333 static void coalesce_file_region(struct resv_map
*resv
, struct file_region
*rg
)
335 struct file_region
*nrg
= NULL
, *prg
= NULL
;
337 prg
= list_prev_entry(rg
, link
);
338 if (&prg
->link
!= &resv
->regions
&& prg
->to
== rg
->from
&&
339 has_same_uncharge_info(prg
, rg
)) {
343 put_uncharge_info(rg
);
349 nrg
= list_next_entry(rg
, link
);
350 if (&nrg
->link
!= &resv
->regions
&& nrg
->from
== rg
->to
&&
351 has_same_uncharge_info(nrg
, rg
)) {
352 nrg
->from
= rg
->from
;
355 put_uncharge_info(rg
);
361 hugetlb_resv_map_add(struct resv_map
*map
, struct file_region
*rg
, long from
,
362 long to
, struct hstate
*h
, struct hugetlb_cgroup
*cg
,
363 long *regions_needed
)
365 struct file_region
*nrg
;
367 if (!regions_needed
) {
368 nrg
= get_file_region_entry_from_cache(map
, from
, to
);
369 record_hugetlb_cgroup_uncharge_info(cg
, h
, map
, nrg
);
370 list_add(&nrg
->link
, rg
->link
.prev
);
371 coalesce_file_region(map
, nrg
);
373 *regions_needed
+= 1;
379 * Must be called with resv->lock held.
381 * Calling this with regions_needed != NULL will count the number of pages
382 * to be added but will not modify the linked list. And regions_needed will
383 * indicate the number of file_regions needed in the cache to carry out to add
384 * the regions for this range.
386 static long add_reservation_in_range(struct resv_map
*resv
, long f
, long t
,
387 struct hugetlb_cgroup
*h_cg
,
388 struct hstate
*h
, long *regions_needed
)
391 struct list_head
*head
= &resv
->regions
;
392 long last_accounted_offset
= f
;
393 struct file_region
*rg
= NULL
, *trg
= NULL
;
398 /* In this loop, we essentially handle an entry for the range
399 * [last_accounted_offset, rg->from), at every iteration, with some
402 list_for_each_entry_safe(rg
, trg
, head
, link
) {
403 /* Skip irrelevant regions that start before our range. */
405 /* If this region ends after the last accounted offset,
406 * then we need to update last_accounted_offset.
408 if (rg
->to
> last_accounted_offset
)
409 last_accounted_offset
= rg
->to
;
413 /* When we find a region that starts beyond our range, we've
419 /* Add an entry for last_accounted_offset -> rg->from, and
420 * update last_accounted_offset.
422 if (rg
->from
> last_accounted_offset
)
423 add
+= hugetlb_resv_map_add(resv
, rg
,
424 last_accounted_offset
,
428 last_accounted_offset
= rg
->to
;
431 /* Handle the case where our range extends beyond
432 * last_accounted_offset.
434 if (last_accounted_offset
< t
)
435 add
+= hugetlb_resv_map_add(resv
, rg
, last_accounted_offset
,
436 t
, h
, h_cg
, regions_needed
);
442 /* Must be called with resv->lock acquired. Will drop lock to allocate entries.
444 static int allocate_file_region_entries(struct resv_map
*resv
,
446 __must_hold(&resv
->lock
)
448 struct list_head allocated_regions
;
449 int to_allocate
= 0, i
= 0;
450 struct file_region
*trg
= NULL
, *rg
= NULL
;
452 VM_BUG_ON(regions_needed
< 0);
454 INIT_LIST_HEAD(&allocated_regions
);
457 * Check for sufficient descriptors in the cache to accommodate
458 * the number of in progress add operations plus regions_needed.
460 * This is a while loop because when we drop the lock, some other call
461 * to region_add or region_del may have consumed some region_entries,
462 * so we keep looping here until we finally have enough entries for
463 * (adds_in_progress + regions_needed).
465 while (resv
->region_cache_count
<
466 (resv
->adds_in_progress
+ regions_needed
)) {
467 to_allocate
= resv
->adds_in_progress
+ regions_needed
-
468 resv
->region_cache_count
;
470 /* At this point, we should have enough entries in the cache
471 * for all the existing adds_in_progress. We should only be
472 * needing to allocate for regions_needed.
474 VM_BUG_ON(resv
->region_cache_count
< resv
->adds_in_progress
);
476 spin_unlock(&resv
->lock
);
477 for (i
= 0; i
< to_allocate
; i
++) {
478 trg
= kmalloc(sizeof(*trg
), GFP_KERNEL
);
481 list_add(&trg
->link
, &allocated_regions
);
484 spin_lock(&resv
->lock
);
486 list_splice(&allocated_regions
, &resv
->region_cache
);
487 resv
->region_cache_count
+= to_allocate
;
493 list_for_each_entry_safe(rg
, trg
, &allocated_regions
, link
) {
501 * Add the huge page range represented by [f, t) to the reserve
502 * map. Regions will be taken from the cache to fill in this range.
503 * Sufficient regions should exist in the cache due to the previous
504 * call to region_chg with the same range, but in some cases the cache will not
505 * have sufficient entries due to races with other code doing region_add or
506 * region_del. The extra needed entries will be allocated.
508 * regions_needed is the out value provided by a previous call to region_chg.
510 * Return the number of new huge pages added to the map. This number is greater
511 * than or equal to zero. If file_region entries needed to be allocated for
512 * this operation and we were not able to allocate, it returns -ENOMEM.
513 * region_add of regions of length 1 never allocate file_regions and cannot
514 * fail; region_chg will always allocate at least 1 entry and a region_add for
515 * 1 page will only require at most 1 entry.
517 static long region_add(struct resv_map
*resv
, long f
, long t
,
518 long in_regions_needed
, struct hstate
*h
,
519 struct hugetlb_cgroup
*h_cg
)
521 long add
= 0, actual_regions_needed
= 0;
523 spin_lock(&resv
->lock
);
526 /* Count how many regions are actually needed to execute this add. */
527 add_reservation_in_range(resv
, f
, t
, NULL
, NULL
,
528 &actual_regions_needed
);
531 * Check for sufficient descriptors in the cache to accommodate
532 * this add operation. Note that actual_regions_needed may be greater
533 * than in_regions_needed, as the resv_map may have been modified since
534 * the region_chg call. In this case, we need to make sure that we
535 * allocate extra entries, such that we have enough for all the
536 * existing adds_in_progress, plus the excess needed for this
539 if (actual_regions_needed
> in_regions_needed
&&
540 resv
->region_cache_count
<
541 resv
->adds_in_progress
+
542 (actual_regions_needed
- in_regions_needed
)) {
543 /* region_add operation of range 1 should never need to
544 * allocate file_region entries.
546 VM_BUG_ON(t
- f
<= 1);
548 if (allocate_file_region_entries(
549 resv
, actual_regions_needed
- in_regions_needed
)) {
556 add
= add_reservation_in_range(resv
, f
, t
, h_cg
, h
, NULL
);
558 resv
->adds_in_progress
-= in_regions_needed
;
560 spin_unlock(&resv
->lock
);
565 * Examine the existing reserve map and determine how many
566 * huge pages in the specified range [f, t) are NOT currently
567 * represented. This routine is called before a subsequent
568 * call to region_add that will actually modify the reserve
569 * map to add the specified range [f, t). region_chg does
570 * not change the number of huge pages represented by the
571 * map. A number of new file_region structures is added to the cache as a
572 * placeholder, for the subsequent region_add call to use. At least 1
573 * file_region structure is added.
575 * out_regions_needed is the number of regions added to the
576 * resv->adds_in_progress. This value needs to be provided to a follow up call
577 * to region_add or region_abort for proper accounting.
579 * Returns the number of huge pages that need to be added to the existing
580 * reservation map for the range [f, t). This number is greater or equal to
581 * zero. -ENOMEM is returned if a new file_region structure or cache entry
582 * is needed and can not be allocated.
584 static long region_chg(struct resv_map
*resv
, long f
, long t
,
585 long *out_regions_needed
)
589 spin_lock(&resv
->lock
);
591 /* Count how many hugepages in this range are NOT represented. */
592 chg
= add_reservation_in_range(resv
, f
, t
, NULL
, NULL
,
595 if (*out_regions_needed
== 0)
596 *out_regions_needed
= 1;
598 if (allocate_file_region_entries(resv
, *out_regions_needed
))
601 resv
->adds_in_progress
+= *out_regions_needed
;
603 spin_unlock(&resv
->lock
);
608 * Abort the in progress add operation. The adds_in_progress field
609 * of the resv_map keeps track of the operations in progress between
610 * calls to region_chg and region_add. Operations are sometimes
611 * aborted after the call to region_chg. In such cases, region_abort
612 * is called to decrement the adds_in_progress counter. regions_needed
613 * is the value returned by the region_chg call, it is used to decrement
614 * the adds_in_progress counter.
616 * NOTE: The range arguments [f, t) are not needed or used in this
617 * routine. They are kept to make reading the calling code easier as
618 * arguments will match the associated region_chg call.
620 static void region_abort(struct resv_map
*resv
, long f
, long t
,
623 spin_lock(&resv
->lock
);
624 VM_BUG_ON(!resv
->region_cache_count
);
625 resv
->adds_in_progress
-= regions_needed
;
626 spin_unlock(&resv
->lock
);
630 * Delete the specified range [f, t) from the reserve map. If the
631 * t parameter is LONG_MAX, this indicates that ALL regions after f
632 * should be deleted. Locate the regions which intersect [f, t)
633 * and either trim, delete or split the existing regions.
635 * Returns the number of huge pages deleted from the reserve map.
636 * In the normal case, the return value is zero or more. In the
637 * case where a region must be split, a new region descriptor must
638 * be allocated. If the allocation fails, -ENOMEM will be returned.
639 * NOTE: If the parameter t == LONG_MAX, then we will never split
640 * a region and possibly return -ENOMEM. Callers specifying
641 * t == LONG_MAX do not need to check for -ENOMEM error.
643 static long region_del(struct resv_map
*resv
, long f
, long t
)
645 struct list_head
*head
= &resv
->regions
;
646 struct file_region
*rg
, *trg
;
647 struct file_region
*nrg
= NULL
;
651 spin_lock(&resv
->lock
);
652 list_for_each_entry_safe(rg
, trg
, head
, link
) {
654 * Skip regions before the range to be deleted. file_region
655 * ranges are normally of the form [from, to). However, there
656 * may be a "placeholder" entry in the map which is of the form
657 * (from, to) with from == to. Check for placeholder entries
658 * at the beginning of the range to be deleted.
660 if (rg
->to
<= f
&& (rg
->to
!= rg
->from
|| rg
->to
!= f
))
666 if (f
> rg
->from
&& t
< rg
->to
) { /* Must split region */
668 * Check for an entry in the cache before dropping
669 * lock and attempting allocation.
672 resv
->region_cache_count
> resv
->adds_in_progress
) {
673 nrg
= list_first_entry(&resv
->region_cache
,
676 list_del(&nrg
->link
);
677 resv
->region_cache_count
--;
681 spin_unlock(&resv
->lock
);
682 nrg
= kmalloc(sizeof(*nrg
), GFP_KERNEL
);
689 hugetlb_cgroup_uncharge_file_region(
690 resv
, rg
, t
- f
, false);
692 /* New entry for end of split region */
696 copy_hugetlb_cgroup_uncharge_info(nrg
, rg
);
698 INIT_LIST_HEAD(&nrg
->link
);
700 /* Original entry is trimmed */
703 list_add(&nrg
->link
, &rg
->link
);
708 if (f
<= rg
->from
&& t
>= rg
->to
) { /* Remove entire region */
709 del
+= rg
->to
- rg
->from
;
710 hugetlb_cgroup_uncharge_file_region(resv
, rg
,
711 rg
->to
- rg
->from
, true);
717 if (f
<= rg
->from
) { /* Trim beginning of region */
718 hugetlb_cgroup_uncharge_file_region(resv
, rg
,
719 t
- rg
->from
, false);
723 } else { /* Trim end of region */
724 hugetlb_cgroup_uncharge_file_region(resv
, rg
,
732 spin_unlock(&resv
->lock
);
738 * A rare out of memory error was encountered which prevented removal of
739 * the reserve map region for a page. The huge page itself was free'ed
740 * and removed from the page cache. This routine will adjust the subpool
741 * usage count, and the global reserve count if needed. By incrementing
742 * these counts, the reserve map entry which could not be deleted will
743 * appear as a "reserved" entry instead of simply dangling with incorrect
746 void hugetlb_fix_reserve_counts(struct inode
*inode
)
748 struct hugepage_subpool
*spool
= subpool_inode(inode
);
750 bool reserved
= false;
752 rsv_adjust
= hugepage_subpool_get_pages(spool
, 1);
753 if (rsv_adjust
> 0) {
754 struct hstate
*h
= hstate_inode(inode
);
756 if (!hugetlb_acct_memory(h
, 1))
758 } else if (!rsv_adjust
) {
763 pr_warn("hugetlb: Huge Page Reserved count may go negative.\n");
767 * Count and return the number of huge pages in the reserve map
768 * that intersect with the range [f, t).
770 static long region_count(struct resv_map
*resv
, long f
, long t
)
772 struct list_head
*head
= &resv
->regions
;
773 struct file_region
*rg
;
776 spin_lock(&resv
->lock
);
777 /* Locate each segment we overlap with, and count that overlap. */
778 list_for_each_entry(rg
, head
, link
) {
787 seg_from
= max(rg
->from
, f
);
788 seg_to
= min(rg
->to
, t
);
790 chg
+= seg_to
- seg_from
;
792 spin_unlock(&resv
->lock
);
798 * Convert the address within this vma to the page offset within
799 * the mapping, in pagecache page units; huge pages here.
801 static pgoff_t
vma_hugecache_offset(struct hstate
*h
,
802 struct vm_area_struct
*vma
, unsigned long address
)
804 return ((address
- vma
->vm_start
) >> huge_page_shift(h
)) +
805 (vma
->vm_pgoff
>> huge_page_order(h
));
808 pgoff_t
linear_hugepage_index(struct vm_area_struct
*vma
,
809 unsigned long address
)
811 return vma_hugecache_offset(hstate_vma(vma
), vma
, address
);
813 EXPORT_SYMBOL_GPL(linear_hugepage_index
);
816 * Return the size of the pages allocated when backing a VMA. In the majority
817 * cases this will be same size as used by the page table entries.
819 unsigned long vma_kernel_pagesize(struct vm_area_struct
*vma
)
821 if (vma
->vm_ops
&& vma
->vm_ops
->pagesize
)
822 return vma
->vm_ops
->pagesize(vma
);
825 EXPORT_SYMBOL_GPL(vma_kernel_pagesize
);
828 * Return the page size being used by the MMU to back a VMA. In the majority
829 * of cases, the page size used by the kernel matches the MMU size. On
830 * architectures where it differs, an architecture-specific 'strong'
831 * version of this symbol is required.
833 __weak
unsigned long vma_mmu_pagesize(struct vm_area_struct
*vma
)
835 return vma_kernel_pagesize(vma
);
839 * Flags for MAP_PRIVATE reservations. These are stored in the bottom
840 * bits of the reservation map pointer, which are always clear due to
843 #define HPAGE_RESV_OWNER (1UL << 0)
844 #define HPAGE_RESV_UNMAPPED (1UL << 1)
845 #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED)
848 * These helpers are used to track how many pages are reserved for
849 * faults in a MAP_PRIVATE mapping. Only the process that called mmap()
850 * is guaranteed to have their future faults succeed.
852 * With the exception of reset_vma_resv_huge_pages() which is called at fork(),
853 * the reserve counters are updated with the hugetlb_lock held. It is safe
854 * to reset the VMA at fork() time as it is not in use yet and there is no
855 * chance of the global counters getting corrupted as a result of the values.
857 * The private mapping reservation is represented in a subtly different
858 * manner to a shared mapping. A shared mapping has a region map associated
859 * with the underlying file, this region map represents the backing file
860 * pages which have ever had a reservation assigned which this persists even
861 * after the page is instantiated. A private mapping has a region map
862 * associated with the original mmap which is attached to all VMAs which
863 * reference it, this region map represents those offsets which have consumed
864 * reservation ie. where pages have been instantiated.
866 static unsigned long get_vma_private_data(struct vm_area_struct
*vma
)
868 return (unsigned long)vma
->vm_private_data
;
871 static void set_vma_private_data(struct vm_area_struct
*vma
,
874 vma
->vm_private_data
= (void *)value
;
878 resv_map_set_hugetlb_cgroup_uncharge_info(struct resv_map
*resv_map
,
879 struct hugetlb_cgroup
*h_cg
,
882 #ifdef CONFIG_CGROUP_HUGETLB
884 resv_map
->reservation_counter
= NULL
;
885 resv_map
->pages_per_hpage
= 0;
886 resv_map
->css
= NULL
;
888 resv_map
->reservation_counter
=
889 &h_cg
->rsvd_hugepage
[hstate_index(h
)];
890 resv_map
->pages_per_hpage
= pages_per_huge_page(h
);
891 resv_map
->css
= &h_cg
->css
;
896 struct resv_map
*resv_map_alloc(void)
898 struct resv_map
*resv_map
= kmalloc(sizeof(*resv_map
), GFP_KERNEL
);
899 struct file_region
*rg
= kmalloc(sizeof(*rg
), GFP_KERNEL
);
901 if (!resv_map
|| !rg
) {
907 kref_init(&resv_map
->refs
);
908 spin_lock_init(&resv_map
->lock
);
909 INIT_LIST_HEAD(&resv_map
->regions
);
911 resv_map
->adds_in_progress
= 0;
913 * Initialize these to 0. On shared mappings, 0's here indicate these
914 * fields don't do cgroup accounting. On private mappings, these will be
915 * re-initialized to the proper values, to indicate that hugetlb cgroup
916 * reservations are to be un-charged from here.
918 resv_map_set_hugetlb_cgroup_uncharge_info(resv_map
, NULL
, NULL
);
920 INIT_LIST_HEAD(&resv_map
->region_cache
);
921 list_add(&rg
->link
, &resv_map
->region_cache
);
922 resv_map
->region_cache_count
= 1;
927 void resv_map_release(struct kref
*ref
)
929 struct resv_map
*resv_map
= container_of(ref
, struct resv_map
, refs
);
930 struct list_head
*head
= &resv_map
->region_cache
;
931 struct file_region
*rg
, *trg
;
933 /* Clear out any active regions before we release the map. */
934 region_del(resv_map
, 0, LONG_MAX
);
936 /* ... and any entries left in the cache */
937 list_for_each_entry_safe(rg
, trg
, head
, link
) {
942 VM_BUG_ON(resv_map
->adds_in_progress
);
947 static inline struct resv_map
*inode_resv_map(struct inode
*inode
)
950 * At inode evict time, i_mapping may not point to the original
951 * address space within the inode. This original address space
952 * contains the pointer to the resv_map. So, always use the
953 * address space embedded within the inode.
954 * The VERY common case is inode->mapping == &inode->i_data but,
955 * this may not be true for device special inodes.
957 return (struct resv_map
*)(&inode
->i_data
)->private_data
;
960 static struct resv_map
*vma_resv_map(struct vm_area_struct
*vma
)
962 VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma
), vma
);
963 if (vma
->vm_flags
& VM_MAYSHARE
) {
964 struct address_space
*mapping
= vma
->vm_file
->f_mapping
;
965 struct inode
*inode
= mapping
->host
;
967 return inode_resv_map(inode
);
970 return (struct resv_map
*)(get_vma_private_data(vma
) &
975 static void set_vma_resv_map(struct vm_area_struct
*vma
, struct resv_map
*map
)
977 VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma
), vma
);
978 VM_BUG_ON_VMA(vma
->vm_flags
& VM_MAYSHARE
, vma
);
980 set_vma_private_data(vma
, (get_vma_private_data(vma
) &
981 HPAGE_RESV_MASK
) | (unsigned long)map
);
984 static void set_vma_resv_flags(struct vm_area_struct
*vma
, unsigned long flags
)
986 VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma
), vma
);
987 VM_BUG_ON_VMA(vma
->vm_flags
& VM_MAYSHARE
, vma
);
989 set_vma_private_data(vma
, get_vma_private_data(vma
) | flags
);
992 static int is_vma_resv_set(struct vm_area_struct
*vma
, unsigned long flag
)
994 VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma
), vma
);
996 return (get_vma_private_data(vma
) & flag
) != 0;
999 /* Reset counters to 0 and clear all HPAGE_RESV_* flags */
1000 void reset_vma_resv_huge_pages(struct vm_area_struct
*vma
)
1002 VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma
), vma
);
1003 if (!(vma
->vm_flags
& VM_MAYSHARE
))
1004 vma
->vm_private_data
= (void *)0;
1007 /* Returns true if the VMA has associated reserve pages */
1008 static bool vma_has_reserves(struct vm_area_struct
*vma
, long chg
)
1010 if (vma
->vm_flags
& VM_NORESERVE
) {
1012 * This address is already reserved by other process(chg == 0),
1013 * so, we should decrement reserved count. Without decrementing,
1014 * reserve count remains after releasing inode, because this
1015 * allocated page will go into page cache and is regarded as
1016 * coming from reserved pool in releasing step. Currently, we
1017 * don't have any other solution to deal with this situation
1018 * properly, so add work-around here.
1020 if (vma
->vm_flags
& VM_MAYSHARE
&& chg
== 0)
1026 /* Shared mappings always use reserves */
1027 if (vma
->vm_flags
& VM_MAYSHARE
) {
1029 * We know VM_NORESERVE is not set. Therefore, there SHOULD
1030 * be a region map for all pages. The only situation where
1031 * there is no region map is if a hole was punched via
1032 * fallocate. In this case, there really are no reserves to
1033 * use. This situation is indicated if chg != 0.
1042 * Only the process that called mmap() has reserves for
1045 if (is_vma_resv_set(vma
, HPAGE_RESV_OWNER
)) {
1047 * Like the shared case above, a hole punch or truncate
1048 * could have been performed on the private mapping.
1049 * Examine the value of chg to determine if reserves
1050 * actually exist or were previously consumed.
1051 * Very Subtle - The value of chg comes from a previous
1052 * call to vma_needs_reserves(). The reserve map for
1053 * private mappings has different (opposite) semantics
1054 * than that of shared mappings. vma_needs_reserves()
1055 * has already taken this difference in semantics into
1056 * account. Therefore, the meaning of chg is the same
1057 * as in the shared case above. Code could easily be
1058 * combined, but keeping it separate draws attention to
1059 * subtle differences.
1070 static void enqueue_huge_page(struct hstate
*h
, struct page
*page
)
1072 int nid
= page_to_nid(page
);
1074 lockdep_assert_held(&hugetlb_lock
);
1075 list_move(&page
->lru
, &h
->hugepage_freelists
[nid
]);
1076 h
->free_huge_pages
++;
1077 h
->free_huge_pages_node
[nid
]++;
1078 SetHPageFreed(page
);
1081 static struct page
*dequeue_huge_page_node_exact(struct hstate
*h
, int nid
)
1084 bool pin
= !!(current
->flags
& PF_MEMALLOC_PIN
);
1086 lockdep_assert_held(&hugetlb_lock
);
1087 list_for_each_entry(page
, &h
->hugepage_freelists
[nid
], lru
) {
1088 if (pin
&& !is_pinnable_page(page
))
1091 if (PageHWPoison(page
))
1094 list_move(&page
->lru
, &h
->hugepage_activelist
);
1095 set_page_refcounted(page
);
1096 ClearHPageFreed(page
);
1097 h
->free_huge_pages
--;
1098 h
->free_huge_pages_node
[nid
]--;
1105 static struct page
*dequeue_huge_page_nodemask(struct hstate
*h
, gfp_t gfp_mask
, int nid
,
1108 unsigned int cpuset_mems_cookie
;
1109 struct zonelist
*zonelist
;
1112 int node
= NUMA_NO_NODE
;
1114 zonelist
= node_zonelist(nid
, gfp_mask
);
1117 cpuset_mems_cookie
= read_mems_allowed_begin();
1118 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, gfp_zone(gfp_mask
), nmask
) {
1121 if (!cpuset_zone_allowed(zone
, gfp_mask
))
1124 * no need to ask again on the same node. Pool is node rather than
1127 if (zone_to_nid(zone
) == node
)
1129 node
= zone_to_nid(zone
);
1131 page
= dequeue_huge_page_node_exact(h
, node
);
1135 if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie
)))
1141 static struct page
*dequeue_huge_page_vma(struct hstate
*h
,
1142 struct vm_area_struct
*vma
,
1143 unsigned long address
, int avoid_reserve
,
1147 struct mempolicy
*mpol
;
1149 nodemask_t
*nodemask
;
1153 * A child process with MAP_PRIVATE mappings created by their parent
1154 * have no page reserves. This check ensures that reservations are
1155 * not "stolen". The child may still get SIGKILLed
1157 if (!vma_has_reserves(vma
, chg
) &&
1158 h
->free_huge_pages
- h
->resv_huge_pages
== 0)
1161 /* If reserves cannot be used, ensure enough pages are in the pool */
1162 if (avoid_reserve
&& h
->free_huge_pages
- h
->resv_huge_pages
== 0)
1165 gfp_mask
= htlb_alloc_mask(h
);
1166 nid
= huge_node(vma
, address
, gfp_mask
, &mpol
, &nodemask
);
1167 page
= dequeue_huge_page_nodemask(h
, gfp_mask
, nid
, nodemask
);
1168 if (page
&& !avoid_reserve
&& vma_has_reserves(vma
, chg
)) {
1169 SetHPageRestoreReserve(page
);
1170 h
->resv_huge_pages
--;
1173 mpol_cond_put(mpol
);
1181 * common helper functions for hstate_next_node_to_{alloc|free}.
1182 * We may have allocated or freed a huge page based on a different
1183 * nodes_allowed previously, so h->next_node_to_{alloc|free} might
1184 * be outside of *nodes_allowed. Ensure that we use an allowed
1185 * node for alloc or free.
1187 static int next_node_allowed(int nid
, nodemask_t
*nodes_allowed
)
1189 nid
= next_node_in(nid
, *nodes_allowed
);
1190 VM_BUG_ON(nid
>= MAX_NUMNODES
);
1195 static int get_valid_node_allowed(int nid
, nodemask_t
*nodes_allowed
)
1197 if (!node_isset(nid
, *nodes_allowed
))
1198 nid
= next_node_allowed(nid
, nodes_allowed
);
1203 * returns the previously saved node ["this node"] from which to
1204 * allocate a persistent huge page for the pool and advance the
1205 * next node from which to allocate, handling wrap at end of node
1208 static int hstate_next_node_to_alloc(struct hstate
*h
,
1209 nodemask_t
*nodes_allowed
)
1213 VM_BUG_ON(!nodes_allowed
);
1215 nid
= get_valid_node_allowed(h
->next_nid_to_alloc
, nodes_allowed
);
1216 h
->next_nid_to_alloc
= next_node_allowed(nid
, nodes_allowed
);
1222 * helper for remove_pool_huge_page() - return the previously saved
1223 * node ["this node"] from which to free a huge page. Advance the
1224 * next node id whether or not we find a free huge page to free so
1225 * that the next attempt to free addresses the next node.
1227 static int hstate_next_node_to_free(struct hstate
*h
, nodemask_t
*nodes_allowed
)
1231 VM_BUG_ON(!nodes_allowed
);
1233 nid
= get_valid_node_allowed(h
->next_nid_to_free
, nodes_allowed
);
1234 h
->next_nid_to_free
= next_node_allowed(nid
, nodes_allowed
);
1239 #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \
1240 for (nr_nodes = nodes_weight(*mask); \
1242 ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \
1245 #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \
1246 for (nr_nodes = nodes_weight(*mask); \
1248 ((node = hstate_next_node_to_free(hs, mask)) || 1); \
1251 #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE
1252 static void destroy_compound_gigantic_page(struct page
*page
,
1256 int nr_pages
= 1 << order
;
1257 struct page
*p
= page
+ 1;
1259 atomic_set(compound_mapcount_ptr(page
), 0);
1260 atomic_set(compound_pincount_ptr(page
), 0);
1262 for (i
= 1; i
< nr_pages
; i
++, p
= mem_map_next(p
, page
, i
)) {
1263 clear_compound_head(p
);
1264 set_page_refcounted(p
);
1267 set_compound_order(page
, 0);
1268 page
[1].compound_nr
= 0;
1269 __ClearPageHead(page
);
1272 static void free_gigantic_page(struct page
*page
, unsigned int order
)
1275 * If the page isn't allocated using the cma allocator,
1276 * cma_release() returns false.
1279 if (cma_release(hugetlb_cma
[page_to_nid(page
)], page
, 1 << order
))
1283 free_contig_range(page_to_pfn(page
), 1 << order
);
1286 #ifdef CONFIG_CONTIG_ALLOC
1287 static struct page
*alloc_gigantic_page(struct hstate
*h
, gfp_t gfp_mask
,
1288 int nid
, nodemask_t
*nodemask
)
1290 unsigned long nr_pages
= pages_per_huge_page(h
);
1291 if (nid
== NUMA_NO_NODE
)
1292 nid
= numa_mem_id();
1299 if (hugetlb_cma
[nid
]) {
1300 page
= cma_alloc(hugetlb_cma
[nid
], nr_pages
,
1301 huge_page_order(h
), true);
1306 if (!(gfp_mask
& __GFP_THISNODE
)) {
1307 for_each_node_mask(node
, *nodemask
) {
1308 if (node
== nid
|| !hugetlb_cma
[node
])
1311 page
= cma_alloc(hugetlb_cma
[node
], nr_pages
,
1312 huge_page_order(h
), true);
1320 return alloc_contig_pages(nr_pages
, gfp_mask
, nid
, nodemask
);
1323 #else /* !CONFIG_CONTIG_ALLOC */
1324 static struct page
*alloc_gigantic_page(struct hstate
*h
, gfp_t gfp_mask
,
1325 int nid
, nodemask_t
*nodemask
)
1329 #endif /* CONFIG_CONTIG_ALLOC */
1331 #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */
1332 static struct page
*alloc_gigantic_page(struct hstate
*h
, gfp_t gfp_mask
,
1333 int nid
, nodemask_t
*nodemask
)
1337 static inline void free_gigantic_page(struct page
*page
, unsigned int order
) { }
1338 static inline void destroy_compound_gigantic_page(struct page
*page
,
1339 unsigned int order
) { }
1343 * Remove hugetlb page from lists, and update dtor so that page appears
1344 * as just a compound page. A reference is held on the page.
1346 * Must be called with hugetlb lock held.
1348 static void remove_hugetlb_page(struct hstate
*h
, struct page
*page
,
1349 bool adjust_surplus
)
1351 int nid
= page_to_nid(page
);
1353 VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page
), page
);
1354 VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page
), page
);
1356 lockdep_assert_held(&hugetlb_lock
);
1357 if (hstate_is_gigantic(h
) && !gigantic_page_runtime_supported())
1360 list_del(&page
->lru
);
1362 if (HPageFreed(page
)) {
1363 h
->free_huge_pages
--;
1364 h
->free_huge_pages_node
[nid
]--;
1366 if (adjust_surplus
) {
1367 h
->surplus_huge_pages
--;
1368 h
->surplus_huge_pages_node
[nid
]--;
1371 set_page_refcounted(page
);
1372 set_compound_page_dtor(page
, NULL_COMPOUND_DTOR
);
1375 h
->nr_huge_pages_node
[nid
]--;
1378 static void add_hugetlb_page(struct hstate
*h
, struct page
*page
,
1379 bool adjust_surplus
)
1382 int nid
= page_to_nid(page
);
1384 VM_BUG_ON_PAGE(!HPageVmemmapOptimized(page
), page
);
1386 lockdep_assert_held(&hugetlb_lock
);
1388 INIT_LIST_HEAD(&page
->lru
);
1390 h
->nr_huge_pages_node
[nid
]++;
1392 if (adjust_surplus
) {
1393 h
->surplus_huge_pages
++;
1394 h
->surplus_huge_pages_node
[nid
]++;
1397 set_compound_page_dtor(page
, HUGETLB_PAGE_DTOR
);
1398 set_page_private(page
, 0);
1399 SetHPageVmemmapOptimized(page
);
1402 * This page is now managed by the hugetlb allocator and has
1403 * no users -- drop the last reference.
1405 zeroed
= put_page_testzero(page
);
1406 VM_BUG_ON_PAGE(!zeroed
, page
);
1407 arch_clear_hugepage_flags(page
);
1408 enqueue_huge_page(h
, page
);
1411 static void __update_and_free_page(struct hstate
*h
, struct page
*page
)
1414 struct page
*subpage
= page
;
1416 if (hstate_is_gigantic(h
) && !gigantic_page_runtime_supported())
1419 if (alloc_huge_page_vmemmap(h
, page
)) {
1420 spin_lock_irq(&hugetlb_lock
);
1422 * If we cannot allocate vmemmap pages, just refuse to free the
1423 * page and put the page back on the hugetlb free list and treat
1424 * as a surplus page.
1426 add_hugetlb_page(h
, page
, true);
1427 spin_unlock_irq(&hugetlb_lock
);
1431 for (i
= 0; i
< pages_per_huge_page(h
);
1432 i
++, subpage
= mem_map_next(subpage
, page
, i
)) {
1433 subpage
->flags
&= ~(1 << PG_locked
| 1 << PG_error
|
1434 1 << PG_referenced
| 1 << PG_dirty
|
1435 1 << PG_active
| 1 << PG_private
|
1438 if (hstate_is_gigantic(h
)) {
1439 destroy_compound_gigantic_page(page
, huge_page_order(h
));
1440 free_gigantic_page(page
, huge_page_order(h
));
1442 __free_pages(page
, huge_page_order(h
));
1447 * As update_and_free_page() can be called under any context, so we cannot
1448 * use GFP_KERNEL to allocate vmemmap pages. However, we can defer the
1449 * actual freeing in a workqueue to prevent from using GFP_ATOMIC to allocate
1450 * the vmemmap pages.
1452 * free_hpage_workfn() locklessly retrieves the linked list of pages to be
1453 * freed and frees them one-by-one. As the page->mapping pointer is going
1454 * to be cleared in free_hpage_workfn() anyway, it is reused as the llist_node
1455 * structure of a lockless linked list of huge pages to be freed.
1457 static LLIST_HEAD(hpage_freelist
);
1459 static void free_hpage_workfn(struct work_struct
*work
)
1461 struct llist_node
*node
;
1463 node
= llist_del_all(&hpage_freelist
);
1469 page
= container_of((struct address_space
**)node
,
1470 struct page
, mapping
);
1472 page
->mapping
= NULL
;
1474 * The VM_BUG_ON_PAGE(!PageHuge(page), page) in page_hstate()
1475 * is going to trigger because a previous call to
1476 * remove_hugetlb_page() will set_compound_page_dtor(page,
1477 * NULL_COMPOUND_DTOR), so do not use page_hstate() directly.
1479 h
= size_to_hstate(page_size(page
));
1481 __update_and_free_page(h
, page
);
1486 static DECLARE_WORK(free_hpage_work
, free_hpage_workfn
);
1488 static inline void flush_free_hpage_work(struct hstate
*h
)
1490 if (free_vmemmap_pages_per_hpage(h
))
1491 flush_work(&free_hpage_work
);
1494 static void update_and_free_page(struct hstate
*h
, struct page
*page
,
1497 if (!HPageVmemmapOptimized(page
) || !atomic
) {
1498 __update_and_free_page(h
, page
);
1503 * Defer freeing to avoid using GFP_ATOMIC to allocate vmemmap pages.
1505 * Only call schedule_work() if hpage_freelist is previously
1506 * empty. Otherwise, schedule_work() had been called but the workfn
1507 * hasn't retrieved the list yet.
1509 if (llist_add((struct llist_node
*)&page
->mapping
, &hpage_freelist
))
1510 schedule_work(&free_hpage_work
);
1513 static void update_and_free_pages_bulk(struct hstate
*h
, struct list_head
*list
)
1515 struct page
*page
, *t_page
;
1517 list_for_each_entry_safe(page
, t_page
, list
, lru
) {
1518 update_and_free_page(h
, page
, false);
1523 struct hstate
*size_to_hstate(unsigned long size
)
1527 for_each_hstate(h
) {
1528 if (huge_page_size(h
) == size
)
1534 void free_huge_page(struct page
*page
)
1537 * Can't pass hstate in here because it is called from the
1538 * compound page destructor.
1540 struct hstate
*h
= page_hstate(page
);
1541 int nid
= page_to_nid(page
);
1542 struct hugepage_subpool
*spool
= hugetlb_page_subpool(page
);
1543 bool restore_reserve
;
1544 unsigned long flags
;
1546 VM_BUG_ON_PAGE(page_count(page
), page
);
1547 VM_BUG_ON_PAGE(page_mapcount(page
), page
);
1549 hugetlb_set_page_subpool(page
, NULL
);
1550 page
->mapping
= NULL
;
1551 restore_reserve
= HPageRestoreReserve(page
);
1552 ClearHPageRestoreReserve(page
);
1555 * If HPageRestoreReserve was set on page, page allocation consumed a
1556 * reservation. If the page was associated with a subpool, there
1557 * would have been a page reserved in the subpool before allocation
1558 * via hugepage_subpool_get_pages(). Since we are 'restoring' the
1559 * reservation, do not call hugepage_subpool_put_pages() as this will
1560 * remove the reserved page from the subpool.
1562 if (!restore_reserve
) {
1564 * A return code of zero implies that the subpool will be
1565 * under its minimum size if the reservation is not restored
1566 * after page is free. Therefore, force restore_reserve
1569 if (hugepage_subpool_put_pages(spool
, 1) == 0)
1570 restore_reserve
= true;
1573 spin_lock_irqsave(&hugetlb_lock
, flags
);
1574 ClearHPageMigratable(page
);
1575 hugetlb_cgroup_uncharge_page(hstate_index(h
),
1576 pages_per_huge_page(h
), page
);
1577 hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h
),
1578 pages_per_huge_page(h
), page
);
1579 if (restore_reserve
)
1580 h
->resv_huge_pages
++;
1582 if (HPageTemporary(page
)) {
1583 remove_hugetlb_page(h
, page
, false);
1584 spin_unlock_irqrestore(&hugetlb_lock
, flags
);
1585 update_and_free_page(h
, page
, true);
1586 } else if (h
->surplus_huge_pages_node
[nid
]) {
1587 /* remove the page from active list */
1588 remove_hugetlb_page(h
, page
, true);
1589 spin_unlock_irqrestore(&hugetlb_lock
, flags
);
1590 update_and_free_page(h
, page
, true);
1592 arch_clear_hugepage_flags(page
);
1593 enqueue_huge_page(h
, page
);
1594 spin_unlock_irqrestore(&hugetlb_lock
, flags
);
1599 * Must be called with the hugetlb lock held
1601 static void __prep_account_new_huge_page(struct hstate
*h
, int nid
)
1603 lockdep_assert_held(&hugetlb_lock
);
1605 h
->nr_huge_pages_node
[nid
]++;
1608 static void __prep_new_huge_page(struct hstate
*h
, struct page
*page
)
1610 free_huge_page_vmemmap(h
, page
);
1611 INIT_LIST_HEAD(&page
->lru
);
1612 set_compound_page_dtor(page
, HUGETLB_PAGE_DTOR
);
1613 hugetlb_set_page_subpool(page
, NULL
);
1614 set_hugetlb_cgroup(page
, NULL
);
1615 set_hugetlb_cgroup_rsvd(page
, NULL
);
1618 static void prep_new_huge_page(struct hstate
*h
, struct page
*page
, int nid
)
1620 __prep_new_huge_page(h
, page
);
1621 spin_lock_irq(&hugetlb_lock
);
1622 __prep_account_new_huge_page(h
, nid
);
1623 spin_unlock_irq(&hugetlb_lock
);
1626 static bool prep_compound_gigantic_page(struct page
*page
, unsigned int order
)
1629 int nr_pages
= 1 << order
;
1630 struct page
*p
= page
+ 1;
1632 /* we rely on prep_new_huge_page to set the destructor */
1633 set_compound_order(page
, order
);
1634 __ClearPageReserved(page
);
1635 __SetPageHead(page
);
1636 for (i
= 1; i
< nr_pages
; i
++, p
= mem_map_next(p
, page
, i
)) {
1638 * For gigantic hugepages allocated through bootmem at
1639 * boot, it's safer to be consistent with the not-gigantic
1640 * hugepages and clear the PG_reserved bit from all tail pages
1641 * too. Otherwise drivers using get_user_pages() to access tail
1642 * pages may get the reference counting wrong if they see
1643 * PG_reserved set on a tail page (despite the head page not
1644 * having PG_reserved set). Enforcing this consistency between
1645 * head and tail pages allows drivers to optimize away a check
1646 * on the head page when they need know if put_page() is needed
1647 * after get_user_pages().
1649 __ClearPageReserved(p
);
1651 * Subtle and very unlikely
1653 * Gigantic 'page allocators' such as memblock or cma will
1654 * return a set of pages with each page ref counted. We need
1655 * to turn this set of pages into a compound page with tail
1656 * page ref counts set to zero. Code such as speculative page
1657 * cache adding could take a ref on a 'to be' tail page.
1658 * We need to respect any increased ref count, and only set
1659 * the ref count to zero if count is currently 1. If count
1660 * is not 1, we call synchronize_rcu in the hope that a rcu
1661 * grace period will cause ref count to drop and then retry.
1662 * If count is still inflated on retry we return an error and
1663 * must discard the pages.
1665 if (!page_ref_freeze(p
, 1)) {
1666 pr_info("HugeTLB unexpected inflated ref count on freshly allocated page\n");
1668 if (!page_ref_freeze(p
, 1))
1671 set_page_count(p
, 0);
1672 set_compound_head(p
, page
);
1674 atomic_set(compound_mapcount_ptr(page
), -1);
1675 atomic_set(compound_pincount_ptr(page
), 0);
1679 /* undo tail page modifications made above */
1681 for (j
= 1; j
< i
; j
++, p
= mem_map_next(p
, page
, j
)) {
1682 clear_compound_head(p
);
1683 set_page_refcounted(p
);
1685 /* need to clear PG_reserved on remaining tail pages */
1686 for (; j
< nr_pages
; j
++, p
= mem_map_next(p
, page
, j
))
1687 __ClearPageReserved(p
);
1688 set_compound_order(page
, 0);
1689 page
[1].compound_nr
= 0;
1690 __ClearPageHead(page
);
1695 * PageHuge() only returns true for hugetlbfs pages, but not for normal or
1696 * transparent huge pages. See the PageTransHuge() documentation for more
1699 int PageHuge(struct page
*page
)
1701 if (!PageCompound(page
))
1704 page
= compound_head(page
);
1705 return page
[1].compound_dtor
== HUGETLB_PAGE_DTOR
;
1707 EXPORT_SYMBOL_GPL(PageHuge
);
1710 * PageHeadHuge() only returns true for hugetlbfs head page, but not for
1711 * normal or transparent huge pages.
1713 int PageHeadHuge(struct page
*page_head
)
1715 if (!PageHead(page_head
))
1718 return page_head
[1].compound_dtor
== HUGETLB_PAGE_DTOR
;
1722 * Find and lock address space (mapping) in write mode.
1724 * Upon entry, the page is locked which means that page_mapping() is
1725 * stable. Due to locking order, we can only trylock_write. If we can
1726 * not get the lock, simply return NULL to caller.
1728 struct address_space
*hugetlb_page_mapping_lock_write(struct page
*hpage
)
1730 struct address_space
*mapping
= page_mapping(hpage
);
1735 if (i_mmap_trylock_write(mapping
))
1741 pgoff_t
hugetlb_basepage_index(struct page
*page
)
1743 struct page
*page_head
= compound_head(page
);
1744 pgoff_t index
= page_index(page_head
);
1745 unsigned long compound_idx
;
1747 if (compound_order(page_head
) >= MAX_ORDER
)
1748 compound_idx
= page_to_pfn(page
) - page_to_pfn(page_head
);
1750 compound_idx
= page
- page_head
;
1752 return (index
<< compound_order(page_head
)) + compound_idx
;
1755 static struct page
*alloc_buddy_huge_page(struct hstate
*h
,
1756 gfp_t gfp_mask
, int nid
, nodemask_t
*nmask
,
1757 nodemask_t
*node_alloc_noretry
)
1759 int order
= huge_page_order(h
);
1761 bool alloc_try_hard
= true;
1764 * By default we always try hard to allocate the page with
1765 * __GFP_RETRY_MAYFAIL flag. However, if we are allocating pages in
1766 * a loop (to adjust global huge page counts) and previous allocation
1767 * failed, do not continue to try hard on the same node. Use the
1768 * node_alloc_noretry bitmap to manage this state information.
1770 if (node_alloc_noretry
&& node_isset(nid
, *node_alloc_noretry
))
1771 alloc_try_hard
= false;
1772 gfp_mask
|= __GFP_COMP
|__GFP_NOWARN
;
1774 gfp_mask
|= __GFP_RETRY_MAYFAIL
;
1775 if (nid
== NUMA_NO_NODE
)
1776 nid
= numa_mem_id();
1777 page
= __alloc_pages(gfp_mask
, order
, nid
, nmask
);
1779 __count_vm_event(HTLB_BUDDY_PGALLOC
);
1781 __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL
);
1784 * If we did not specify __GFP_RETRY_MAYFAIL, but still got a page this
1785 * indicates an overall state change. Clear bit so that we resume
1786 * normal 'try hard' allocations.
1788 if (node_alloc_noretry
&& page
&& !alloc_try_hard
)
1789 node_clear(nid
, *node_alloc_noretry
);
1792 * If we tried hard to get a page but failed, set bit so that
1793 * subsequent attempts will not try as hard until there is an
1794 * overall state change.
1796 if (node_alloc_noretry
&& !page
&& alloc_try_hard
)
1797 node_set(nid
, *node_alloc_noretry
);
1803 * Common helper to allocate a fresh hugetlb page. All specific allocators
1804 * should use this function to get new hugetlb pages
1806 static struct page
*alloc_fresh_huge_page(struct hstate
*h
,
1807 gfp_t gfp_mask
, int nid
, nodemask_t
*nmask
,
1808 nodemask_t
*node_alloc_noretry
)
1814 if (hstate_is_gigantic(h
))
1815 page
= alloc_gigantic_page(h
, gfp_mask
, nid
, nmask
);
1817 page
= alloc_buddy_huge_page(h
, gfp_mask
,
1818 nid
, nmask
, node_alloc_noretry
);
1822 if (hstate_is_gigantic(h
)) {
1823 if (!prep_compound_gigantic_page(page
, huge_page_order(h
))) {
1825 * Rare failure to convert pages to compound page.
1826 * Free pages and try again - ONCE!
1828 free_gigantic_page(page
, huge_page_order(h
));
1833 pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n");
1837 prep_new_huge_page(h
, page
, page_to_nid(page
));
1843 * Allocates a fresh page to the hugetlb allocator pool in the node interleaved
1846 static int alloc_pool_huge_page(struct hstate
*h
, nodemask_t
*nodes_allowed
,
1847 nodemask_t
*node_alloc_noretry
)
1851 gfp_t gfp_mask
= htlb_alloc_mask(h
) | __GFP_THISNODE
;
1853 for_each_node_mask_to_alloc(h
, nr_nodes
, node
, nodes_allowed
) {
1854 page
= alloc_fresh_huge_page(h
, gfp_mask
, node
, nodes_allowed
,
1855 node_alloc_noretry
);
1863 put_page(page
); /* free it into the hugepage allocator */
1869 * Remove huge page from pool from next node to free. Attempt to keep
1870 * persistent huge pages more or less balanced over allowed nodes.
1871 * This routine only 'removes' the hugetlb page. The caller must make
1872 * an additional call to free the page to low level allocators.
1873 * Called with hugetlb_lock locked.
1875 static struct page
*remove_pool_huge_page(struct hstate
*h
,
1876 nodemask_t
*nodes_allowed
,
1880 struct page
*page
= NULL
;
1882 lockdep_assert_held(&hugetlb_lock
);
1883 for_each_node_mask_to_free(h
, nr_nodes
, node
, nodes_allowed
) {
1885 * If we're returning unused surplus pages, only examine
1886 * nodes with surplus pages.
1888 if ((!acct_surplus
|| h
->surplus_huge_pages_node
[node
]) &&
1889 !list_empty(&h
->hugepage_freelists
[node
])) {
1890 page
= list_entry(h
->hugepage_freelists
[node
].next
,
1892 remove_hugetlb_page(h
, page
, acct_surplus
);
1901 * Dissolve a given free hugepage into free buddy pages. This function does
1902 * nothing for in-use hugepages and non-hugepages.
1903 * This function returns values like below:
1905 * -ENOMEM: failed to allocate vmemmap pages to free the freed hugepages
1906 * when the system is under memory pressure and the feature of
1907 * freeing unused vmemmap pages associated with each hugetlb page
1909 * -EBUSY: failed to dissolved free hugepages or the hugepage is in-use
1910 * (allocated or reserved.)
1911 * 0: successfully dissolved free hugepages or the page is not a
1912 * hugepage (considered as already dissolved)
1914 int dissolve_free_huge_page(struct page
*page
)
1919 /* Not to disrupt normal path by vainly holding hugetlb_lock */
1920 if (!PageHuge(page
))
1923 spin_lock_irq(&hugetlb_lock
);
1924 if (!PageHuge(page
)) {
1929 if (!page_count(page
)) {
1930 struct page
*head
= compound_head(page
);
1931 struct hstate
*h
= page_hstate(head
);
1932 if (h
->free_huge_pages
- h
->resv_huge_pages
== 0)
1936 * We should make sure that the page is already on the free list
1937 * when it is dissolved.
1939 if (unlikely(!HPageFreed(head
))) {
1940 spin_unlock_irq(&hugetlb_lock
);
1944 * Theoretically, we should return -EBUSY when we
1945 * encounter this race. In fact, we have a chance
1946 * to successfully dissolve the page if we do a
1947 * retry. Because the race window is quite small.
1948 * If we seize this opportunity, it is an optimization
1949 * for increasing the success rate of dissolving page.
1954 remove_hugetlb_page(h
, head
, false);
1955 h
->max_huge_pages
--;
1956 spin_unlock_irq(&hugetlb_lock
);
1959 * Normally update_and_free_page will allocate required vmemmmap
1960 * before freeing the page. update_and_free_page will fail to
1961 * free the page if it can not allocate required vmemmap. We
1962 * need to adjust max_huge_pages if the page is not freed.
1963 * Attempt to allocate vmemmmap here so that we can take
1964 * appropriate action on failure.
1966 rc
= alloc_huge_page_vmemmap(h
, head
);
1969 * Move PageHWPoison flag from head page to the raw
1970 * error page, which makes any subpages rather than
1971 * the error page reusable.
1973 if (PageHWPoison(head
) && page
!= head
) {
1974 SetPageHWPoison(page
);
1975 ClearPageHWPoison(head
);
1977 update_and_free_page(h
, head
, false);
1979 spin_lock_irq(&hugetlb_lock
);
1980 add_hugetlb_page(h
, head
, false);
1981 h
->max_huge_pages
++;
1982 spin_unlock_irq(&hugetlb_lock
);
1988 spin_unlock_irq(&hugetlb_lock
);
1993 * Dissolve free hugepages in a given pfn range. Used by memory hotplug to
1994 * make specified memory blocks removable from the system.
1995 * Note that this will dissolve a free gigantic hugepage completely, if any
1996 * part of it lies within the given range.
1997 * Also note that if dissolve_free_huge_page() returns with an error, all
1998 * free hugepages that were dissolved before that error are lost.
2000 int dissolve_free_huge_pages(unsigned long start_pfn
, unsigned long end_pfn
)
2006 if (!hugepages_supported())
2009 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= 1 << minimum_order
) {
2010 page
= pfn_to_page(pfn
);
2011 rc
= dissolve_free_huge_page(page
);
2020 * Allocates a fresh surplus page from the page allocator.
2022 static struct page
*alloc_surplus_huge_page(struct hstate
*h
, gfp_t gfp_mask
,
2023 int nid
, nodemask_t
*nmask
)
2025 struct page
*page
= NULL
;
2027 if (hstate_is_gigantic(h
))
2030 spin_lock_irq(&hugetlb_lock
);
2031 if (h
->surplus_huge_pages
>= h
->nr_overcommit_huge_pages
)
2033 spin_unlock_irq(&hugetlb_lock
);
2035 page
= alloc_fresh_huge_page(h
, gfp_mask
, nid
, nmask
, NULL
);
2039 spin_lock_irq(&hugetlb_lock
);
2041 * We could have raced with the pool size change.
2042 * Double check that and simply deallocate the new page
2043 * if we would end up overcommiting the surpluses. Abuse
2044 * temporary page to workaround the nasty free_huge_page
2047 if (h
->surplus_huge_pages
>= h
->nr_overcommit_huge_pages
) {
2048 SetHPageTemporary(page
);
2049 spin_unlock_irq(&hugetlb_lock
);
2053 h
->surplus_huge_pages
++;
2054 h
->surplus_huge_pages_node
[page_to_nid(page
)]++;
2058 spin_unlock_irq(&hugetlb_lock
);
2063 static struct page
*alloc_migrate_huge_page(struct hstate
*h
, gfp_t gfp_mask
,
2064 int nid
, nodemask_t
*nmask
)
2068 if (hstate_is_gigantic(h
))
2071 page
= alloc_fresh_huge_page(h
, gfp_mask
, nid
, nmask
, NULL
);
2076 * We do not account these pages as surplus because they are only
2077 * temporary and will be released properly on the last reference
2079 SetHPageTemporary(page
);
2085 * Use the VMA's mpolicy to allocate a huge page from the buddy.
2088 struct page
*alloc_buddy_huge_page_with_mpol(struct hstate
*h
,
2089 struct vm_area_struct
*vma
, unsigned long addr
)
2092 struct mempolicy
*mpol
;
2093 gfp_t gfp_mask
= htlb_alloc_mask(h
);
2095 nodemask_t
*nodemask
;
2097 nid
= huge_node(vma
, addr
, gfp_mask
, &mpol
, &nodemask
);
2098 page
= alloc_surplus_huge_page(h
, gfp_mask
, nid
, nodemask
);
2099 mpol_cond_put(mpol
);
2104 /* page migration callback function */
2105 struct page
*alloc_huge_page_nodemask(struct hstate
*h
, int preferred_nid
,
2106 nodemask_t
*nmask
, gfp_t gfp_mask
)
2108 spin_lock_irq(&hugetlb_lock
);
2109 if (h
->free_huge_pages
- h
->resv_huge_pages
> 0) {
2112 page
= dequeue_huge_page_nodemask(h
, gfp_mask
, preferred_nid
, nmask
);
2114 spin_unlock_irq(&hugetlb_lock
);
2118 spin_unlock_irq(&hugetlb_lock
);
2120 return alloc_migrate_huge_page(h
, gfp_mask
, preferred_nid
, nmask
);
2123 /* mempolicy aware migration callback */
2124 struct page
*alloc_huge_page_vma(struct hstate
*h
, struct vm_area_struct
*vma
,
2125 unsigned long address
)
2127 struct mempolicy
*mpol
;
2128 nodemask_t
*nodemask
;
2133 gfp_mask
= htlb_alloc_mask(h
);
2134 node
= huge_node(vma
, address
, gfp_mask
, &mpol
, &nodemask
);
2135 page
= alloc_huge_page_nodemask(h
, node
, nodemask
, gfp_mask
);
2136 mpol_cond_put(mpol
);
2142 * Increase the hugetlb pool such that it can accommodate a reservation
2145 static int gather_surplus_pages(struct hstate
*h
, long delta
)
2146 __must_hold(&hugetlb_lock
)
2148 struct list_head surplus_list
;
2149 struct page
*page
, *tmp
;
2152 long needed
, allocated
;
2153 bool alloc_ok
= true;
2155 lockdep_assert_held(&hugetlb_lock
);
2156 needed
= (h
->resv_huge_pages
+ delta
) - h
->free_huge_pages
;
2158 h
->resv_huge_pages
+= delta
;
2163 INIT_LIST_HEAD(&surplus_list
);
2167 spin_unlock_irq(&hugetlb_lock
);
2168 for (i
= 0; i
< needed
; i
++) {
2169 page
= alloc_surplus_huge_page(h
, htlb_alloc_mask(h
),
2170 NUMA_NO_NODE
, NULL
);
2175 list_add(&page
->lru
, &surplus_list
);
2181 * After retaking hugetlb_lock, we need to recalculate 'needed'
2182 * because either resv_huge_pages or free_huge_pages may have changed.
2184 spin_lock_irq(&hugetlb_lock
);
2185 needed
= (h
->resv_huge_pages
+ delta
) -
2186 (h
->free_huge_pages
+ allocated
);
2191 * We were not able to allocate enough pages to
2192 * satisfy the entire reservation so we free what
2193 * we've allocated so far.
2198 * The surplus_list now contains _at_least_ the number of extra pages
2199 * needed to accommodate the reservation. Add the appropriate number
2200 * of pages to the hugetlb pool and free the extras back to the buddy
2201 * allocator. Commit the entire reservation here to prevent another
2202 * process from stealing the pages as they are added to the pool but
2203 * before they are reserved.
2205 needed
+= allocated
;
2206 h
->resv_huge_pages
+= delta
;
2209 /* Free the needed pages to the hugetlb pool */
2210 list_for_each_entry_safe(page
, tmp
, &surplus_list
, lru
) {
2216 * This page is now managed by the hugetlb allocator and has
2217 * no users -- drop the buddy allocator's reference.
2219 zeroed
= put_page_testzero(page
);
2220 VM_BUG_ON_PAGE(!zeroed
, page
);
2221 enqueue_huge_page(h
, page
);
2224 spin_unlock_irq(&hugetlb_lock
);
2226 /* Free unnecessary surplus pages to the buddy allocator */
2227 list_for_each_entry_safe(page
, tmp
, &surplus_list
, lru
)
2229 spin_lock_irq(&hugetlb_lock
);
2235 * This routine has two main purposes:
2236 * 1) Decrement the reservation count (resv_huge_pages) by the value passed
2237 * in unused_resv_pages. This corresponds to the prior adjustments made
2238 * to the associated reservation map.
2239 * 2) Free any unused surplus pages that may have been allocated to satisfy
2240 * the reservation. As many as unused_resv_pages may be freed.
2242 static void return_unused_surplus_pages(struct hstate
*h
,
2243 unsigned long unused_resv_pages
)
2245 unsigned long nr_pages
;
2247 LIST_HEAD(page_list
);
2249 lockdep_assert_held(&hugetlb_lock
);
2250 /* Uncommit the reservation */
2251 h
->resv_huge_pages
-= unused_resv_pages
;
2253 /* Cannot return gigantic pages currently */
2254 if (hstate_is_gigantic(h
))
2258 * Part (or even all) of the reservation could have been backed
2259 * by pre-allocated pages. Only free surplus pages.
2261 nr_pages
= min(unused_resv_pages
, h
->surplus_huge_pages
);
2264 * We want to release as many surplus pages as possible, spread
2265 * evenly across all nodes with memory. Iterate across these nodes
2266 * until we can no longer free unreserved surplus pages. This occurs
2267 * when the nodes with surplus pages have no free pages.
2268 * remove_pool_huge_page() will balance the freed pages across the
2269 * on-line nodes with memory and will handle the hstate accounting.
2271 while (nr_pages
--) {
2272 page
= remove_pool_huge_page(h
, &node_states
[N_MEMORY
], 1);
2276 list_add(&page
->lru
, &page_list
);
2280 spin_unlock_irq(&hugetlb_lock
);
2281 update_and_free_pages_bulk(h
, &page_list
);
2282 spin_lock_irq(&hugetlb_lock
);
2287 * vma_needs_reservation, vma_commit_reservation and vma_end_reservation
2288 * are used by the huge page allocation routines to manage reservations.
2290 * vma_needs_reservation is called to determine if the huge page at addr
2291 * within the vma has an associated reservation. If a reservation is
2292 * needed, the value 1 is returned. The caller is then responsible for
2293 * managing the global reservation and subpool usage counts. After
2294 * the huge page has been allocated, vma_commit_reservation is called
2295 * to add the page to the reservation map. If the page allocation fails,
2296 * the reservation must be ended instead of committed. vma_end_reservation
2297 * is called in such cases.
2299 * In the normal case, vma_commit_reservation returns the same value
2300 * as the preceding vma_needs_reservation call. The only time this
2301 * is not the case is if a reserve map was changed between calls. It
2302 * is the responsibility of the caller to notice the difference and
2303 * take appropriate action.
2305 * vma_add_reservation is used in error paths where a reservation must
2306 * be restored when a newly allocated huge page must be freed. It is
2307 * to be called after calling vma_needs_reservation to determine if a
2308 * reservation exists.
2310 * vma_del_reservation is used in error paths where an entry in the reserve
2311 * map was created during huge page allocation and must be removed. It is to
2312 * be called after calling vma_needs_reservation to determine if a reservation
2315 enum vma_resv_mode
{
2322 static long __vma_reservation_common(struct hstate
*h
,
2323 struct vm_area_struct
*vma
, unsigned long addr
,
2324 enum vma_resv_mode mode
)
2326 struct resv_map
*resv
;
2329 long dummy_out_regions_needed
;
2331 resv
= vma_resv_map(vma
);
2335 idx
= vma_hugecache_offset(h
, vma
, addr
);
2337 case VMA_NEEDS_RESV
:
2338 ret
= region_chg(resv
, idx
, idx
+ 1, &dummy_out_regions_needed
);
2339 /* We assume that vma_reservation_* routines always operate on
2340 * 1 page, and that adding to resv map a 1 page entry can only
2341 * ever require 1 region.
2343 VM_BUG_ON(dummy_out_regions_needed
!= 1);
2345 case VMA_COMMIT_RESV
:
2346 ret
= region_add(resv
, idx
, idx
+ 1, 1, NULL
, NULL
);
2347 /* region_add calls of range 1 should never fail. */
2351 region_abort(resv
, idx
, idx
+ 1, 1);
2355 if (vma
->vm_flags
& VM_MAYSHARE
) {
2356 ret
= region_add(resv
, idx
, idx
+ 1, 1, NULL
, NULL
);
2357 /* region_add calls of range 1 should never fail. */
2360 region_abort(resv
, idx
, idx
+ 1, 1);
2361 ret
= region_del(resv
, idx
, idx
+ 1);
2365 if (vma
->vm_flags
& VM_MAYSHARE
) {
2366 region_abort(resv
, idx
, idx
+ 1, 1);
2367 ret
= region_del(resv
, idx
, idx
+ 1);
2369 ret
= region_add(resv
, idx
, idx
+ 1, 1, NULL
, NULL
);
2370 /* region_add calls of range 1 should never fail. */
2378 if (vma
->vm_flags
& VM_MAYSHARE
|| mode
== VMA_DEL_RESV
)
2381 * We know private mapping must have HPAGE_RESV_OWNER set.
2383 * In most cases, reserves always exist for private mappings.
2384 * However, a file associated with mapping could have been
2385 * hole punched or truncated after reserves were consumed.
2386 * As subsequent fault on such a range will not use reserves.
2387 * Subtle - The reserve map for private mappings has the
2388 * opposite meaning than that of shared mappings. If NO
2389 * entry is in the reserve map, it means a reservation exists.
2390 * If an entry exists in the reserve map, it means the
2391 * reservation has already been consumed. As a result, the
2392 * return value of this routine is the opposite of the
2393 * value returned from reserve map manipulation routines above.
2402 static long vma_needs_reservation(struct hstate
*h
,
2403 struct vm_area_struct
*vma
, unsigned long addr
)
2405 return __vma_reservation_common(h
, vma
, addr
, VMA_NEEDS_RESV
);
2408 static long vma_commit_reservation(struct hstate
*h
,
2409 struct vm_area_struct
*vma
, unsigned long addr
)
2411 return __vma_reservation_common(h
, vma
, addr
, VMA_COMMIT_RESV
);
2414 static void vma_end_reservation(struct hstate
*h
,
2415 struct vm_area_struct
*vma
, unsigned long addr
)
2417 (void)__vma_reservation_common(h
, vma
, addr
, VMA_END_RESV
);
2420 static long vma_add_reservation(struct hstate
*h
,
2421 struct vm_area_struct
*vma
, unsigned long addr
)
2423 return __vma_reservation_common(h
, vma
, addr
, VMA_ADD_RESV
);
2426 static long vma_del_reservation(struct hstate
*h
,
2427 struct vm_area_struct
*vma
, unsigned long addr
)
2429 return __vma_reservation_common(h
, vma
, addr
, VMA_DEL_RESV
);
2433 * This routine is called to restore reservation information on error paths.
2434 * It should ONLY be called for pages allocated via alloc_huge_page(), and
2435 * the hugetlb mutex should remain held when calling this routine.
2437 * It handles two specific cases:
2438 * 1) A reservation was in place and the page consumed the reservation.
2439 * HPageRestoreReserve is set in the page.
2440 * 2) No reservation was in place for the page, so HPageRestoreReserve is
2441 * not set. However, alloc_huge_page always updates the reserve map.
2443 * In case 1, free_huge_page later in the error path will increment the
2444 * global reserve count. But, free_huge_page does not have enough context
2445 * to adjust the reservation map. This case deals primarily with private
2446 * mappings. Adjust the reserve map here to be consistent with global
2447 * reserve count adjustments to be made by free_huge_page. Make sure the
2448 * reserve map indicates there is a reservation present.
2450 * In case 2, simply undo reserve map modifications done by alloc_huge_page.
2452 void restore_reserve_on_error(struct hstate
*h
, struct vm_area_struct
*vma
,
2453 unsigned long address
, struct page
*page
)
2455 long rc
= vma_needs_reservation(h
, vma
, address
);
2457 if (HPageRestoreReserve(page
)) {
2458 if (unlikely(rc
< 0))
2460 * Rare out of memory condition in reserve map
2461 * manipulation. Clear HPageRestoreReserve so that
2462 * global reserve count will not be incremented
2463 * by free_huge_page. This will make it appear
2464 * as though the reservation for this page was
2465 * consumed. This may prevent the task from
2466 * faulting in the page at a later time. This
2467 * is better than inconsistent global huge page
2468 * accounting of reserve counts.
2470 ClearHPageRestoreReserve(page
);
2472 (void)vma_add_reservation(h
, vma
, address
);
2474 vma_end_reservation(h
, vma
, address
);
2478 * This indicates there is an entry in the reserve map
2479 * added by alloc_huge_page. We know it was added
2480 * before the alloc_huge_page call, otherwise
2481 * HPageRestoreReserve would be set on the page.
2482 * Remove the entry so that a subsequent allocation
2483 * does not consume a reservation.
2485 rc
= vma_del_reservation(h
, vma
, address
);
2488 * VERY rare out of memory condition. Since
2489 * we can not delete the entry, set
2490 * HPageRestoreReserve so that the reserve
2491 * count will be incremented when the page
2492 * is freed. This reserve will be consumed
2493 * on a subsequent allocation.
2495 SetHPageRestoreReserve(page
);
2496 } else if (rc
< 0) {
2498 * Rare out of memory condition from
2499 * vma_needs_reservation call. Memory allocation is
2500 * only attempted if a new entry is needed. Therefore,
2501 * this implies there is not an entry in the
2504 * For shared mappings, no entry in the map indicates
2505 * no reservation. We are done.
2507 if (!(vma
->vm_flags
& VM_MAYSHARE
))
2509 * For private mappings, no entry indicates
2510 * a reservation is present. Since we can
2511 * not add an entry, set SetHPageRestoreReserve
2512 * on the page so reserve count will be
2513 * incremented when freed. This reserve will
2514 * be consumed on a subsequent allocation.
2516 SetHPageRestoreReserve(page
);
2519 * No reservation present, do nothing
2521 vma_end_reservation(h
, vma
, address
);
2526 * alloc_and_dissolve_huge_page - Allocate a new page and dissolve the old one
2527 * @h: struct hstate old page belongs to
2528 * @old_page: Old page to dissolve
2529 * @list: List to isolate the page in case we need to
2530 * Returns 0 on success, otherwise negated error.
2532 static int alloc_and_dissolve_huge_page(struct hstate
*h
, struct page
*old_page
,
2533 struct list_head
*list
)
2535 gfp_t gfp_mask
= htlb_alloc_mask(h
) | __GFP_THISNODE
;
2536 int nid
= page_to_nid(old_page
);
2537 struct page
*new_page
;
2541 * Before dissolving the page, we need to allocate a new one for the
2542 * pool to remain stable. Here, we allocate the page and 'prep' it
2543 * by doing everything but actually updating counters and adding to
2544 * the pool. This simplifies and let us do most of the processing
2547 new_page
= alloc_buddy_huge_page(h
, gfp_mask
, nid
, NULL
, NULL
);
2550 __prep_new_huge_page(h
, new_page
);
2553 spin_lock_irq(&hugetlb_lock
);
2554 if (!PageHuge(old_page
)) {
2556 * Freed from under us. Drop new_page too.
2559 } else if (page_count(old_page
)) {
2561 * Someone has grabbed the page, try to isolate it here.
2562 * Fail with -EBUSY if not possible.
2564 spin_unlock_irq(&hugetlb_lock
);
2565 if (!isolate_huge_page(old_page
, list
))
2567 spin_lock_irq(&hugetlb_lock
);
2569 } else if (!HPageFreed(old_page
)) {
2571 * Page's refcount is 0 but it has not been enqueued in the
2572 * freelist yet. Race window is small, so we can succeed here if
2575 spin_unlock_irq(&hugetlb_lock
);
2580 * Ok, old_page is still a genuine free hugepage. Remove it from
2581 * the freelist and decrease the counters. These will be
2582 * incremented again when calling __prep_account_new_huge_page()
2583 * and enqueue_huge_page() for new_page. The counters will remain
2584 * stable since this happens under the lock.
2586 remove_hugetlb_page(h
, old_page
, false);
2589 * Reference count trick is needed because allocator gives us
2590 * referenced page but the pool requires pages with 0 refcount.
2592 __prep_account_new_huge_page(h
, nid
);
2593 page_ref_dec(new_page
);
2594 enqueue_huge_page(h
, new_page
);
2597 * Pages have been replaced, we can safely free the old one.
2599 spin_unlock_irq(&hugetlb_lock
);
2600 update_and_free_page(h
, old_page
, false);
2606 spin_unlock_irq(&hugetlb_lock
);
2607 update_and_free_page(h
, new_page
, false);
2612 int isolate_or_dissolve_huge_page(struct page
*page
, struct list_head
*list
)
2619 * The page might have been dissolved from under our feet, so make sure
2620 * to carefully check the state under the lock.
2621 * Return success when racing as if we dissolved the page ourselves.
2623 spin_lock_irq(&hugetlb_lock
);
2624 if (PageHuge(page
)) {
2625 head
= compound_head(page
);
2626 h
= page_hstate(head
);
2628 spin_unlock_irq(&hugetlb_lock
);
2631 spin_unlock_irq(&hugetlb_lock
);
2634 * Fence off gigantic pages as there is a cyclic dependency between
2635 * alloc_contig_range and them. Return -ENOMEM as this has the effect
2636 * of bailing out right away without further retrying.
2638 if (hstate_is_gigantic(h
))
2641 if (page_count(head
) && isolate_huge_page(head
, list
))
2643 else if (!page_count(head
))
2644 ret
= alloc_and_dissolve_huge_page(h
, head
, list
);
2649 struct page
*alloc_huge_page(struct vm_area_struct
*vma
,
2650 unsigned long addr
, int avoid_reserve
)
2652 struct hugepage_subpool
*spool
= subpool_vma(vma
);
2653 struct hstate
*h
= hstate_vma(vma
);
2655 long map_chg
, map_commit
;
2658 struct hugetlb_cgroup
*h_cg
;
2659 bool deferred_reserve
;
2661 idx
= hstate_index(h
);
2663 * Examine the region/reserve map to determine if the process
2664 * has a reservation for the page to be allocated. A return
2665 * code of zero indicates a reservation exists (no change).
2667 map_chg
= gbl_chg
= vma_needs_reservation(h
, vma
, addr
);
2669 return ERR_PTR(-ENOMEM
);
2672 * Processes that did not create the mapping will have no
2673 * reserves as indicated by the region/reserve map. Check
2674 * that the allocation will not exceed the subpool limit.
2675 * Allocations for MAP_NORESERVE mappings also need to be
2676 * checked against any subpool limit.
2678 if (map_chg
|| avoid_reserve
) {
2679 gbl_chg
= hugepage_subpool_get_pages(spool
, 1);
2681 vma_end_reservation(h
, vma
, addr
);
2682 return ERR_PTR(-ENOSPC
);
2686 * Even though there was no reservation in the region/reserve
2687 * map, there could be reservations associated with the
2688 * subpool that can be used. This would be indicated if the
2689 * return value of hugepage_subpool_get_pages() is zero.
2690 * However, if avoid_reserve is specified we still avoid even
2691 * the subpool reservations.
2697 /* If this allocation is not consuming a reservation, charge it now.
2699 deferred_reserve
= map_chg
|| avoid_reserve
;
2700 if (deferred_reserve
) {
2701 ret
= hugetlb_cgroup_charge_cgroup_rsvd(
2702 idx
, pages_per_huge_page(h
), &h_cg
);
2704 goto out_subpool_put
;
2707 ret
= hugetlb_cgroup_charge_cgroup(idx
, pages_per_huge_page(h
), &h_cg
);
2709 goto out_uncharge_cgroup_reservation
;
2711 spin_lock_irq(&hugetlb_lock
);
2713 * glb_chg is passed to indicate whether or not a page must be taken
2714 * from the global free pool (global change). gbl_chg == 0 indicates
2715 * a reservation exists for the allocation.
2717 page
= dequeue_huge_page_vma(h
, vma
, addr
, avoid_reserve
, gbl_chg
);
2719 spin_unlock_irq(&hugetlb_lock
);
2720 page
= alloc_buddy_huge_page_with_mpol(h
, vma
, addr
);
2722 goto out_uncharge_cgroup
;
2723 if (!avoid_reserve
&& vma_has_reserves(vma
, gbl_chg
)) {
2724 SetHPageRestoreReserve(page
);
2725 h
->resv_huge_pages
--;
2727 spin_lock_irq(&hugetlb_lock
);
2728 list_add(&page
->lru
, &h
->hugepage_activelist
);
2731 hugetlb_cgroup_commit_charge(idx
, pages_per_huge_page(h
), h_cg
, page
);
2732 /* If allocation is not consuming a reservation, also store the
2733 * hugetlb_cgroup pointer on the page.
2735 if (deferred_reserve
) {
2736 hugetlb_cgroup_commit_charge_rsvd(idx
, pages_per_huge_page(h
),
2740 spin_unlock_irq(&hugetlb_lock
);
2742 hugetlb_set_page_subpool(page
, spool
);
2744 map_commit
= vma_commit_reservation(h
, vma
, addr
);
2745 if (unlikely(map_chg
> map_commit
)) {
2747 * The page was added to the reservation map between
2748 * vma_needs_reservation and vma_commit_reservation.
2749 * This indicates a race with hugetlb_reserve_pages.
2750 * Adjust for the subpool count incremented above AND
2751 * in hugetlb_reserve_pages for the same page. Also,
2752 * the reservation count added in hugetlb_reserve_pages
2753 * no longer applies.
2757 rsv_adjust
= hugepage_subpool_put_pages(spool
, 1);
2758 hugetlb_acct_memory(h
, -rsv_adjust
);
2759 if (deferred_reserve
)
2760 hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h
),
2761 pages_per_huge_page(h
), page
);
2765 out_uncharge_cgroup
:
2766 hugetlb_cgroup_uncharge_cgroup(idx
, pages_per_huge_page(h
), h_cg
);
2767 out_uncharge_cgroup_reservation
:
2768 if (deferred_reserve
)
2769 hugetlb_cgroup_uncharge_cgroup_rsvd(idx
, pages_per_huge_page(h
),
2772 if (map_chg
|| avoid_reserve
)
2773 hugepage_subpool_put_pages(spool
, 1);
2774 vma_end_reservation(h
, vma
, addr
);
2775 return ERR_PTR(-ENOSPC
);
2778 int alloc_bootmem_huge_page(struct hstate
*h
)
2779 __attribute__ ((weak
, alias("__alloc_bootmem_huge_page")));
2780 int __alloc_bootmem_huge_page(struct hstate
*h
)
2782 struct huge_bootmem_page
*m
;
2785 for_each_node_mask_to_alloc(h
, nr_nodes
, node
, &node_states
[N_MEMORY
]) {
2788 addr
= memblock_alloc_try_nid_raw(
2789 huge_page_size(h
), huge_page_size(h
),
2790 0, MEMBLOCK_ALLOC_ACCESSIBLE
, node
);
2793 * Use the beginning of the huge page to store the
2794 * huge_bootmem_page struct (until gather_bootmem
2795 * puts them into the mem_map).
2804 BUG_ON(!IS_ALIGNED(virt_to_phys(m
), huge_page_size(h
)));
2805 /* Put them into a private list first because mem_map is not up yet */
2806 INIT_LIST_HEAD(&m
->list
);
2807 list_add(&m
->list
, &huge_boot_pages
);
2813 * Put bootmem huge pages into the standard lists after mem_map is up.
2814 * Note: This only applies to gigantic (order > MAX_ORDER) pages.
2816 static void __init
gather_bootmem_prealloc(void)
2818 struct huge_bootmem_page
*m
;
2820 list_for_each_entry(m
, &huge_boot_pages
, list
) {
2821 struct page
*page
= virt_to_page(m
);
2822 struct hstate
*h
= m
->hstate
;
2824 VM_BUG_ON(!hstate_is_gigantic(h
));
2825 WARN_ON(page_count(page
) != 1);
2826 if (prep_compound_gigantic_page(page
, huge_page_order(h
))) {
2827 WARN_ON(PageReserved(page
));
2828 prep_new_huge_page(h
, page
, page_to_nid(page
));
2829 put_page(page
); /* add to the hugepage allocator */
2831 free_gigantic_page(page
, huge_page_order(h
));
2832 pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n");
2836 * We need to restore the 'stolen' pages to totalram_pages
2837 * in order to fix confusing memory reports from free(1) and
2838 * other side-effects, like CommitLimit going negative.
2840 adjust_managed_page_count(page
, pages_per_huge_page(h
));
2845 static void __init
hugetlb_hstate_alloc_pages(struct hstate
*h
)
2848 nodemask_t
*node_alloc_noretry
;
2850 if (!hstate_is_gigantic(h
)) {
2852 * Bit mask controlling how hard we retry per-node allocations.
2853 * Ignore errors as lower level routines can deal with
2854 * node_alloc_noretry == NULL. If this kmalloc fails at boot
2855 * time, we are likely in bigger trouble.
2857 node_alloc_noretry
= kmalloc(sizeof(*node_alloc_noretry
),
2860 /* allocations done at boot time */
2861 node_alloc_noretry
= NULL
;
2864 /* bit mask controlling how hard we retry per-node allocations */
2865 if (node_alloc_noretry
)
2866 nodes_clear(*node_alloc_noretry
);
2868 for (i
= 0; i
< h
->max_huge_pages
; ++i
) {
2869 if (hstate_is_gigantic(h
)) {
2870 if (hugetlb_cma_size
) {
2871 pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n");
2874 if (!alloc_bootmem_huge_page(h
))
2876 } else if (!alloc_pool_huge_page(h
,
2877 &node_states
[N_MEMORY
],
2878 node_alloc_noretry
))
2882 if (i
< h
->max_huge_pages
) {
2885 string_get_size(huge_page_size(h
), 1, STRING_UNITS_2
, buf
, 32);
2886 pr_warn("HugeTLB: allocating %lu of page size %s failed. Only allocated %lu hugepages.\n",
2887 h
->max_huge_pages
, buf
, i
);
2888 h
->max_huge_pages
= i
;
2891 kfree(node_alloc_noretry
);
2894 static void __init
hugetlb_init_hstates(void)
2898 for_each_hstate(h
) {
2899 if (minimum_order
> huge_page_order(h
))
2900 minimum_order
= huge_page_order(h
);
2902 /* oversize hugepages were init'ed in early boot */
2903 if (!hstate_is_gigantic(h
))
2904 hugetlb_hstate_alloc_pages(h
);
2906 VM_BUG_ON(minimum_order
== UINT_MAX
);
2909 static void __init
report_hugepages(void)
2913 for_each_hstate(h
) {
2916 string_get_size(huge_page_size(h
), 1, STRING_UNITS_2
, buf
, 32);
2917 pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n",
2918 buf
, h
->free_huge_pages
);
2922 #ifdef CONFIG_HIGHMEM
2923 static void try_to_free_low(struct hstate
*h
, unsigned long count
,
2924 nodemask_t
*nodes_allowed
)
2927 LIST_HEAD(page_list
);
2929 lockdep_assert_held(&hugetlb_lock
);
2930 if (hstate_is_gigantic(h
))
2934 * Collect pages to be freed on a list, and free after dropping lock
2936 for_each_node_mask(i
, *nodes_allowed
) {
2937 struct page
*page
, *next
;
2938 struct list_head
*freel
= &h
->hugepage_freelists
[i
];
2939 list_for_each_entry_safe(page
, next
, freel
, lru
) {
2940 if (count
>= h
->nr_huge_pages
)
2942 if (PageHighMem(page
))
2944 remove_hugetlb_page(h
, page
, false);
2945 list_add(&page
->lru
, &page_list
);
2950 spin_unlock_irq(&hugetlb_lock
);
2951 update_and_free_pages_bulk(h
, &page_list
);
2952 spin_lock_irq(&hugetlb_lock
);
2955 static inline void try_to_free_low(struct hstate
*h
, unsigned long count
,
2956 nodemask_t
*nodes_allowed
)
2962 * Increment or decrement surplus_huge_pages. Keep node-specific counters
2963 * balanced by operating on them in a round-robin fashion.
2964 * Returns 1 if an adjustment was made.
2966 static int adjust_pool_surplus(struct hstate
*h
, nodemask_t
*nodes_allowed
,
2971 lockdep_assert_held(&hugetlb_lock
);
2972 VM_BUG_ON(delta
!= -1 && delta
!= 1);
2975 for_each_node_mask_to_alloc(h
, nr_nodes
, node
, nodes_allowed
) {
2976 if (h
->surplus_huge_pages_node
[node
])
2980 for_each_node_mask_to_free(h
, nr_nodes
, node
, nodes_allowed
) {
2981 if (h
->surplus_huge_pages_node
[node
] <
2982 h
->nr_huge_pages_node
[node
])
2989 h
->surplus_huge_pages
+= delta
;
2990 h
->surplus_huge_pages_node
[node
] += delta
;
2994 #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)
2995 static int set_max_huge_pages(struct hstate
*h
, unsigned long count
, int nid
,
2996 nodemask_t
*nodes_allowed
)
2998 unsigned long min_count
, ret
;
3000 LIST_HEAD(page_list
);
3001 NODEMASK_ALLOC(nodemask_t
, node_alloc_noretry
, GFP_KERNEL
);
3004 * Bit mask controlling how hard we retry per-node allocations.
3005 * If we can not allocate the bit mask, do not attempt to allocate
3006 * the requested huge pages.
3008 if (node_alloc_noretry
)
3009 nodes_clear(*node_alloc_noretry
);
3014 * resize_lock mutex prevents concurrent adjustments to number of
3015 * pages in hstate via the proc/sysfs interfaces.
3017 mutex_lock(&h
->resize_lock
);
3018 flush_free_hpage_work(h
);
3019 spin_lock_irq(&hugetlb_lock
);
3022 * Check for a node specific request.
3023 * Changing node specific huge page count may require a corresponding
3024 * change to the global count. In any case, the passed node mask
3025 * (nodes_allowed) will restrict alloc/free to the specified node.
3027 if (nid
!= NUMA_NO_NODE
) {
3028 unsigned long old_count
= count
;
3030 count
+= h
->nr_huge_pages
- h
->nr_huge_pages_node
[nid
];
3032 * User may have specified a large count value which caused the
3033 * above calculation to overflow. In this case, they wanted
3034 * to allocate as many huge pages as possible. Set count to
3035 * largest possible value to align with their intention.
3037 if (count
< old_count
)
3042 * Gigantic pages runtime allocation depend on the capability for large
3043 * page range allocation.
3044 * If the system does not provide this feature, return an error when
3045 * the user tries to allocate gigantic pages but let the user free the
3046 * boottime allocated gigantic pages.
3048 if (hstate_is_gigantic(h
) && !IS_ENABLED(CONFIG_CONTIG_ALLOC
)) {
3049 if (count
> persistent_huge_pages(h
)) {
3050 spin_unlock_irq(&hugetlb_lock
);
3051 mutex_unlock(&h
->resize_lock
);
3052 NODEMASK_FREE(node_alloc_noretry
);
3055 /* Fall through to decrease pool */
3059 * Increase the pool size
3060 * First take pages out of surplus state. Then make up the
3061 * remaining difference by allocating fresh huge pages.
3063 * We might race with alloc_surplus_huge_page() here and be unable
3064 * to convert a surplus huge page to a normal huge page. That is
3065 * not critical, though, it just means the overall size of the
3066 * pool might be one hugepage larger than it needs to be, but
3067 * within all the constraints specified by the sysctls.
3069 while (h
->surplus_huge_pages
&& count
> persistent_huge_pages(h
)) {
3070 if (!adjust_pool_surplus(h
, nodes_allowed
, -1))
3074 while (count
> persistent_huge_pages(h
)) {
3076 * If this allocation races such that we no longer need the
3077 * page, free_huge_page will handle it by freeing the page
3078 * and reducing the surplus.
3080 spin_unlock_irq(&hugetlb_lock
);
3082 /* yield cpu to avoid soft lockup */
3085 ret
= alloc_pool_huge_page(h
, nodes_allowed
,
3086 node_alloc_noretry
);
3087 spin_lock_irq(&hugetlb_lock
);
3091 /* Bail for signals. Probably ctrl-c from user */
3092 if (signal_pending(current
))
3097 * Decrease the pool size
3098 * First return free pages to the buddy allocator (being careful
3099 * to keep enough around to satisfy reservations). Then place
3100 * pages into surplus state as needed so the pool will shrink
3101 * to the desired size as pages become free.
3103 * By placing pages into the surplus state independent of the
3104 * overcommit value, we are allowing the surplus pool size to
3105 * exceed overcommit. There are few sane options here. Since
3106 * alloc_surplus_huge_page() is checking the global counter,
3107 * though, we'll note that we're not allowed to exceed surplus
3108 * and won't grow the pool anywhere else. Not until one of the
3109 * sysctls are changed, or the surplus pages go out of use.
3111 min_count
= h
->resv_huge_pages
+ h
->nr_huge_pages
- h
->free_huge_pages
;
3112 min_count
= max(count
, min_count
);
3113 try_to_free_low(h
, min_count
, nodes_allowed
);
3116 * Collect pages to be removed on list without dropping lock
3118 while (min_count
< persistent_huge_pages(h
)) {
3119 page
= remove_pool_huge_page(h
, nodes_allowed
, 0);
3123 list_add(&page
->lru
, &page_list
);
3125 /* free the pages after dropping lock */
3126 spin_unlock_irq(&hugetlb_lock
);
3127 update_and_free_pages_bulk(h
, &page_list
);
3128 flush_free_hpage_work(h
);
3129 spin_lock_irq(&hugetlb_lock
);
3131 while (count
< persistent_huge_pages(h
)) {
3132 if (!adjust_pool_surplus(h
, nodes_allowed
, 1))
3136 h
->max_huge_pages
= persistent_huge_pages(h
);
3137 spin_unlock_irq(&hugetlb_lock
);
3138 mutex_unlock(&h
->resize_lock
);
3140 NODEMASK_FREE(node_alloc_noretry
);
3145 #define HSTATE_ATTR_RO(_name) \
3146 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
3148 #define HSTATE_ATTR(_name) \
3149 static struct kobj_attribute _name##_attr = \
3150 __ATTR(_name, 0644, _name##_show, _name##_store)
3152 static struct kobject
*hugepages_kobj
;
3153 static struct kobject
*hstate_kobjs
[HUGE_MAX_HSTATE
];
3155 static struct hstate
*kobj_to_node_hstate(struct kobject
*kobj
, int *nidp
);
3157 static struct hstate
*kobj_to_hstate(struct kobject
*kobj
, int *nidp
)
3161 for (i
= 0; i
< HUGE_MAX_HSTATE
; i
++)
3162 if (hstate_kobjs
[i
] == kobj
) {
3164 *nidp
= NUMA_NO_NODE
;
3168 return kobj_to_node_hstate(kobj
, nidp
);
3171 static ssize_t
nr_hugepages_show_common(struct kobject
*kobj
,
3172 struct kobj_attribute
*attr
, char *buf
)
3175 unsigned long nr_huge_pages
;
3178 h
= kobj_to_hstate(kobj
, &nid
);
3179 if (nid
== NUMA_NO_NODE
)
3180 nr_huge_pages
= h
->nr_huge_pages
;
3182 nr_huge_pages
= h
->nr_huge_pages_node
[nid
];
3184 return sysfs_emit(buf
, "%lu\n", nr_huge_pages
);
3187 static ssize_t
__nr_hugepages_store_common(bool obey_mempolicy
,
3188 struct hstate
*h
, int nid
,
3189 unsigned long count
, size_t len
)
3192 nodemask_t nodes_allowed
, *n_mask
;
3194 if (hstate_is_gigantic(h
) && !gigantic_page_runtime_supported())
3197 if (nid
== NUMA_NO_NODE
) {
3199 * global hstate attribute
3201 if (!(obey_mempolicy
&&
3202 init_nodemask_of_mempolicy(&nodes_allowed
)))
3203 n_mask
= &node_states
[N_MEMORY
];
3205 n_mask
= &nodes_allowed
;
3208 * Node specific request. count adjustment happens in
3209 * set_max_huge_pages() after acquiring hugetlb_lock.
3211 init_nodemask_of_node(&nodes_allowed
, nid
);
3212 n_mask
= &nodes_allowed
;
3215 err
= set_max_huge_pages(h
, count
, nid
, n_mask
);
3217 return err
? err
: len
;
3220 static ssize_t
nr_hugepages_store_common(bool obey_mempolicy
,
3221 struct kobject
*kobj
, const char *buf
,
3225 unsigned long count
;
3229 err
= kstrtoul(buf
, 10, &count
);
3233 h
= kobj_to_hstate(kobj
, &nid
);
3234 return __nr_hugepages_store_common(obey_mempolicy
, h
, nid
, count
, len
);
3237 static ssize_t
nr_hugepages_show(struct kobject
*kobj
,
3238 struct kobj_attribute
*attr
, char *buf
)
3240 return nr_hugepages_show_common(kobj
, attr
, buf
);
3243 static ssize_t
nr_hugepages_store(struct kobject
*kobj
,
3244 struct kobj_attribute
*attr
, const char *buf
, size_t len
)
3246 return nr_hugepages_store_common(false, kobj
, buf
, len
);
3248 HSTATE_ATTR(nr_hugepages
);
3253 * hstate attribute for optionally mempolicy-based constraint on persistent
3254 * huge page alloc/free.
3256 static ssize_t
nr_hugepages_mempolicy_show(struct kobject
*kobj
,
3257 struct kobj_attribute
*attr
,
3260 return nr_hugepages_show_common(kobj
, attr
, buf
);
3263 static ssize_t
nr_hugepages_mempolicy_store(struct kobject
*kobj
,
3264 struct kobj_attribute
*attr
, const char *buf
, size_t len
)
3266 return nr_hugepages_store_common(true, kobj
, buf
, len
);
3268 HSTATE_ATTR(nr_hugepages_mempolicy
);
3272 static ssize_t
nr_overcommit_hugepages_show(struct kobject
*kobj
,
3273 struct kobj_attribute
*attr
, char *buf
)
3275 struct hstate
*h
= kobj_to_hstate(kobj
, NULL
);
3276 return sysfs_emit(buf
, "%lu\n", h
->nr_overcommit_huge_pages
);
3279 static ssize_t
nr_overcommit_hugepages_store(struct kobject
*kobj
,
3280 struct kobj_attribute
*attr
, const char *buf
, size_t count
)
3283 unsigned long input
;
3284 struct hstate
*h
= kobj_to_hstate(kobj
, NULL
);
3286 if (hstate_is_gigantic(h
))
3289 err
= kstrtoul(buf
, 10, &input
);
3293 spin_lock_irq(&hugetlb_lock
);
3294 h
->nr_overcommit_huge_pages
= input
;
3295 spin_unlock_irq(&hugetlb_lock
);
3299 HSTATE_ATTR(nr_overcommit_hugepages
);
3301 static ssize_t
free_hugepages_show(struct kobject
*kobj
,
3302 struct kobj_attribute
*attr
, char *buf
)
3305 unsigned long free_huge_pages
;
3308 h
= kobj_to_hstate(kobj
, &nid
);
3309 if (nid
== NUMA_NO_NODE
)
3310 free_huge_pages
= h
->free_huge_pages
;
3312 free_huge_pages
= h
->free_huge_pages_node
[nid
];
3314 return sysfs_emit(buf
, "%lu\n", free_huge_pages
);
3316 HSTATE_ATTR_RO(free_hugepages
);
3318 static ssize_t
resv_hugepages_show(struct kobject
*kobj
,
3319 struct kobj_attribute
*attr
, char *buf
)
3321 struct hstate
*h
= kobj_to_hstate(kobj
, NULL
);
3322 return sysfs_emit(buf
, "%lu\n", h
->resv_huge_pages
);
3324 HSTATE_ATTR_RO(resv_hugepages
);
3326 static ssize_t
surplus_hugepages_show(struct kobject
*kobj
,
3327 struct kobj_attribute
*attr
, char *buf
)
3330 unsigned long surplus_huge_pages
;
3333 h
= kobj_to_hstate(kobj
, &nid
);
3334 if (nid
== NUMA_NO_NODE
)
3335 surplus_huge_pages
= h
->surplus_huge_pages
;
3337 surplus_huge_pages
= h
->surplus_huge_pages_node
[nid
];
3339 return sysfs_emit(buf
, "%lu\n", surplus_huge_pages
);
3341 HSTATE_ATTR_RO(surplus_hugepages
);
3343 static struct attribute
*hstate_attrs
[] = {
3344 &nr_hugepages_attr
.attr
,
3345 &nr_overcommit_hugepages_attr
.attr
,
3346 &free_hugepages_attr
.attr
,
3347 &resv_hugepages_attr
.attr
,
3348 &surplus_hugepages_attr
.attr
,
3350 &nr_hugepages_mempolicy_attr
.attr
,
3355 static const struct attribute_group hstate_attr_group
= {
3356 .attrs
= hstate_attrs
,
3359 static int hugetlb_sysfs_add_hstate(struct hstate
*h
, struct kobject
*parent
,
3360 struct kobject
**hstate_kobjs
,
3361 const struct attribute_group
*hstate_attr_group
)
3364 int hi
= hstate_index(h
);
3366 hstate_kobjs
[hi
] = kobject_create_and_add(h
->name
, parent
);
3367 if (!hstate_kobjs
[hi
])
3370 retval
= sysfs_create_group(hstate_kobjs
[hi
], hstate_attr_group
);
3372 kobject_put(hstate_kobjs
[hi
]);
3373 hstate_kobjs
[hi
] = NULL
;
3379 static void __init
hugetlb_sysfs_init(void)
3384 hugepages_kobj
= kobject_create_and_add("hugepages", mm_kobj
);
3385 if (!hugepages_kobj
)
3388 for_each_hstate(h
) {
3389 err
= hugetlb_sysfs_add_hstate(h
, hugepages_kobj
,
3390 hstate_kobjs
, &hstate_attr_group
);
3392 pr_err("HugeTLB: Unable to add hstate %s", h
->name
);
3399 * node_hstate/s - associate per node hstate attributes, via their kobjects,
3400 * with node devices in node_devices[] using a parallel array. The array
3401 * index of a node device or _hstate == node id.
3402 * This is here to avoid any static dependency of the node device driver, in
3403 * the base kernel, on the hugetlb module.
3405 struct node_hstate
{
3406 struct kobject
*hugepages_kobj
;
3407 struct kobject
*hstate_kobjs
[HUGE_MAX_HSTATE
];
3409 static struct node_hstate node_hstates
[MAX_NUMNODES
];
3412 * A subset of global hstate attributes for node devices
3414 static struct attribute
*per_node_hstate_attrs
[] = {
3415 &nr_hugepages_attr
.attr
,
3416 &free_hugepages_attr
.attr
,
3417 &surplus_hugepages_attr
.attr
,
3421 static const struct attribute_group per_node_hstate_attr_group
= {
3422 .attrs
= per_node_hstate_attrs
,
3426 * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj.
3427 * Returns node id via non-NULL nidp.
3429 static struct hstate
*kobj_to_node_hstate(struct kobject
*kobj
, int *nidp
)
3433 for (nid
= 0; nid
< nr_node_ids
; nid
++) {
3434 struct node_hstate
*nhs
= &node_hstates
[nid
];
3436 for (i
= 0; i
< HUGE_MAX_HSTATE
; i
++)
3437 if (nhs
->hstate_kobjs
[i
] == kobj
) {
3449 * Unregister hstate attributes from a single node device.
3450 * No-op if no hstate attributes attached.
3452 static void hugetlb_unregister_node(struct node
*node
)
3455 struct node_hstate
*nhs
= &node_hstates
[node
->dev
.id
];
3457 if (!nhs
->hugepages_kobj
)
3458 return; /* no hstate attributes */
3460 for_each_hstate(h
) {
3461 int idx
= hstate_index(h
);
3462 if (nhs
->hstate_kobjs
[idx
]) {
3463 kobject_put(nhs
->hstate_kobjs
[idx
]);
3464 nhs
->hstate_kobjs
[idx
] = NULL
;
3468 kobject_put(nhs
->hugepages_kobj
);
3469 nhs
->hugepages_kobj
= NULL
;
3474 * Register hstate attributes for a single node device.
3475 * No-op if attributes already registered.
3477 static void hugetlb_register_node(struct node
*node
)
3480 struct node_hstate
*nhs
= &node_hstates
[node
->dev
.id
];
3483 if (nhs
->hugepages_kobj
)
3484 return; /* already allocated */
3486 nhs
->hugepages_kobj
= kobject_create_and_add("hugepages",
3488 if (!nhs
->hugepages_kobj
)
3491 for_each_hstate(h
) {
3492 err
= hugetlb_sysfs_add_hstate(h
, nhs
->hugepages_kobj
,
3494 &per_node_hstate_attr_group
);
3496 pr_err("HugeTLB: Unable to add hstate %s for node %d\n",
3497 h
->name
, node
->dev
.id
);
3498 hugetlb_unregister_node(node
);
3505 * hugetlb init time: register hstate attributes for all registered node
3506 * devices of nodes that have memory. All on-line nodes should have
3507 * registered their associated device by this time.
3509 static void __init
hugetlb_register_all_nodes(void)
3513 for_each_node_state(nid
, N_MEMORY
) {
3514 struct node
*node
= node_devices
[nid
];
3515 if (node
->dev
.id
== nid
)
3516 hugetlb_register_node(node
);
3520 * Let the node device driver know we're here so it can
3521 * [un]register hstate attributes on node hotplug.
3523 register_hugetlbfs_with_node(hugetlb_register_node
,
3524 hugetlb_unregister_node
);
3526 #else /* !CONFIG_NUMA */
3528 static struct hstate
*kobj_to_node_hstate(struct kobject
*kobj
, int *nidp
)
3536 static void hugetlb_register_all_nodes(void) { }
3540 static int __init
hugetlb_init(void)
3544 BUILD_BUG_ON(sizeof_field(struct page
, private) * BITS_PER_BYTE
<
3547 if (!hugepages_supported()) {
3548 if (hugetlb_max_hstate
|| default_hstate_max_huge_pages
)
3549 pr_warn("HugeTLB: huge pages not supported, ignoring associated command-line parameters\n");
3554 * Make sure HPAGE_SIZE (HUGETLB_PAGE_ORDER) hstate exists. Some
3555 * architectures depend on setup being done here.
3557 hugetlb_add_hstate(HUGETLB_PAGE_ORDER
);
3558 if (!parsed_default_hugepagesz
) {
3560 * If we did not parse a default huge page size, set
3561 * default_hstate_idx to HPAGE_SIZE hstate. And, if the
3562 * number of huge pages for this default size was implicitly
3563 * specified, set that here as well.
3564 * Note that the implicit setting will overwrite an explicit
3565 * setting. A warning will be printed in this case.
3567 default_hstate_idx
= hstate_index(size_to_hstate(HPAGE_SIZE
));
3568 if (default_hstate_max_huge_pages
) {
3569 if (default_hstate
.max_huge_pages
) {
3572 string_get_size(huge_page_size(&default_hstate
),
3573 1, STRING_UNITS_2
, buf
, 32);
3574 pr_warn("HugeTLB: Ignoring hugepages=%lu associated with %s page size\n",
3575 default_hstate
.max_huge_pages
, buf
);
3576 pr_warn("HugeTLB: Using hugepages=%lu for number of default huge pages\n",
3577 default_hstate_max_huge_pages
);
3579 default_hstate
.max_huge_pages
=
3580 default_hstate_max_huge_pages
;
3584 hugetlb_cma_check();
3585 hugetlb_init_hstates();
3586 gather_bootmem_prealloc();
3589 hugetlb_sysfs_init();
3590 hugetlb_register_all_nodes();
3591 hugetlb_cgroup_file_init();
3594 num_fault_mutexes
= roundup_pow_of_two(8 * num_possible_cpus());
3596 num_fault_mutexes
= 1;
3598 hugetlb_fault_mutex_table
=
3599 kmalloc_array(num_fault_mutexes
, sizeof(struct mutex
),
3601 BUG_ON(!hugetlb_fault_mutex_table
);
3603 for (i
= 0; i
< num_fault_mutexes
; i
++)
3604 mutex_init(&hugetlb_fault_mutex_table
[i
]);
3607 subsys_initcall(hugetlb_init
);
3609 /* Overwritten by architectures with more huge page sizes */
3610 bool __init
__attribute((weak
)) arch_hugetlb_valid_size(unsigned long size
)
3612 return size
== HPAGE_SIZE
;
3615 void __init
hugetlb_add_hstate(unsigned int order
)
3620 if (size_to_hstate(PAGE_SIZE
<< order
)) {
3623 BUG_ON(hugetlb_max_hstate
>= HUGE_MAX_HSTATE
);
3625 h
= &hstates
[hugetlb_max_hstate
++];
3626 mutex_init(&h
->resize_lock
);
3628 h
->mask
= ~(huge_page_size(h
) - 1);
3629 for (i
= 0; i
< MAX_NUMNODES
; ++i
)
3630 INIT_LIST_HEAD(&h
->hugepage_freelists
[i
]);
3631 INIT_LIST_HEAD(&h
->hugepage_activelist
);
3632 h
->next_nid_to_alloc
= first_memory_node
;
3633 h
->next_nid_to_free
= first_memory_node
;
3634 snprintf(h
->name
, HSTATE_NAME_LEN
, "hugepages-%lukB",
3635 huge_page_size(h
)/1024);
3636 hugetlb_vmemmap_init(h
);
3642 * hugepages command line processing
3643 * hugepages normally follows a valid hugepagsz or default_hugepagsz
3644 * specification. If not, ignore the hugepages value. hugepages can also
3645 * be the first huge page command line option in which case it implicitly
3646 * specifies the number of huge pages for the default size.
3648 static int __init
hugepages_setup(char *s
)
3651 static unsigned long *last_mhp
;
3653 if (!parsed_valid_hugepagesz
) {
3654 pr_warn("HugeTLB: hugepages=%s does not follow a valid hugepagesz, ignoring\n", s
);
3655 parsed_valid_hugepagesz
= true;
3660 * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter
3661 * yet, so this hugepages= parameter goes to the "default hstate".
3662 * Otherwise, it goes with the previously parsed hugepagesz or
3663 * default_hugepagesz.
3665 else if (!hugetlb_max_hstate
)
3666 mhp
= &default_hstate_max_huge_pages
;
3668 mhp
= &parsed_hstate
->max_huge_pages
;
3670 if (mhp
== last_mhp
) {
3671 pr_warn("HugeTLB: hugepages= specified twice without interleaving hugepagesz=, ignoring hugepages=%s\n", s
);
3675 if (sscanf(s
, "%lu", mhp
) <= 0)
3679 * Global state is always initialized later in hugetlb_init.
3680 * But we need to allocate gigantic hstates here early to still
3681 * use the bootmem allocator.
3683 if (hugetlb_max_hstate
&& hstate_is_gigantic(parsed_hstate
))
3684 hugetlb_hstate_alloc_pages(parsed_hstate
);
3690 __setup("hugepages=", hugepages_setup
);
3693 * hugepagesz command line processing
3694 * A specific huge page size can only be specified once with hugepagesz.
3695 * hugepagesz is followed by hugepages on the command line. The global
3696 * variable 'parsed_valid_hugepagesz' is used to determine if prior
3697 * hugepagesz argument was valid.
3699 static int __init
hugepagesz_setup(char *s
)
3704 parsed_valid_hugepagesz
= false;
3705 size
= (unsigned long)memparse(s
, NULL
);
3707 if (!arch_hugetlb_valid_size(size
)) {
3708 pr_err("HugeTLB: unsupported hugepagesz=%s\n", s
);
3712 h
= size_to_hstate(size
);
3715 * hstate for this size already exists. This is normally
3716 * an error, but is allowed if the existing hstate is the
3717 * default hstate. More specifically, it is only allowed if
3718 * the number of huge pages for the default hstate was not
3719 * previously specified.
3721 if (!parsed_default_hugepagesz
|| h
!= &default_hstate
||
3722 default_hstate
.max_huge_pages
) {
3723 pr_warn("HugeTLB: hugepagesz=%s specified twice, ignoring\n", s
);
3728 * No need to call hugetlb_add_hstate() as hstate already
3729 * exists. But, do set parsed_hstate so that a following
3730 * hugepages= parameter will be applied to this hstate.
3733 parsed_valid_hugepagesz
= true;
3737 hugetlb_add_hstate(ilog2(size
) - PAGE_SHIFT
);
3738 parsed_valid_hugepagesz
= true;
3741 __setup("hugepagesz=", hugepagesz_setup
);
3744 * default_hugepagesz command line input
3745 * Only one instance of default_hugepagesz allowed on command line.
3747 static int __init
default_hugepagesz_setup(char *s
)
3751 parsed_valid_hugepagesz
= false;
3752 if (parsed_default_hugepagesz
) {
3753 pr_err("HugeTLB: default_hugepagesz previously specified, ignoring %s\n", s
);
3757 size
= (unsigned long)memparse(s
, NULL
);
3759 if (!arch_hugetlb_valid_size(size
)) {
3760 pr_err("HugeTLB: unsupported default_hugepagesz=%s\n", s
);
3764 hugetlb_add_hstate(ilog2(size
) - PAGE_SHIFT
);
3765 parsed_valid_hugepagesz
= true;
3766 parsed_default_hugepagesz
= true;
3767 default_hstate_idx
= hstate_index(size_to_hstate(size
));
3770 * The number of default huge pages (for this size) could have been
3771 * specified as the first hugetlb parameter: hugepages=X. If so,
3772 * then default_hstate_max_huge_pages is set. If the default huge
3773 * page size is gigantic (>= MAX_ORDER), then the pages must be
3774 * allocated here from bootmem allocator.
3776 if (default_hstate_max_huge_pages
) {
3777 default_hstate
.max_huge_pages
= default_hstate_max_huge_pages
;
3778 if (hstate_is_gigantic(&default_hstate
))
3779 hugetlb_hstate_alloc_pages(&default_hstate
);
3780 default_hstate_max_huge_pages
= 0;
3785 __setup("default_hugepagesz=", default_hugepagesz_setup
);
3787 static unsigned int allowed_mems_nr(struct hstate
*h
)
3790 unsigned int nr
= 0;
3791 nodemask_t
*mpol_allowed
;
3792 unsigned int *array
= h
->free_huge_pages_node
;
3793 gfp_t gfp_mask
= htlb_alloc_mask(h
);
3795 mpol_allowed
= policy_nodemask_current(gfp_mask
);
3797 for_each_node_mask(node
, cpuset_current_mems_allowed
) {
3798 if (!mpol_allowed
|| node_isset(node
, *mpol_allowed
))
3805 #ifdef CONFIG_SYSCTL
3806 static int proc_hugetlb_doulongvec_minmax(struct ctl_table
*table
, int write
,
3807 void *buffer
, size_t *length
,
3808 loff_t
*ppos
, unsigned long *out
)
3810 struct ctl_table dup_table
;
3813 * In order to avoid races with __do_proc_doulongvec_minmax(), we
3814 * can duplicate the @table and alter the duplicate of it.
3817 dup_table
.data
= out
;
3819 return proc_doulongvec_minmax(&dup_table
, write
, buffer
, length
, ppos
);
3822 static int hugetlb_sysctl_handler_common(bool obey_mempolicy
,
3823 struct ctl_table
*table
, int write
,
3824 void *buffer
, size_t *length
, loff_t
*ppos
)
3826 struct hstate
*h
= &default_hstate
;
3827 unsigned long tmp
= h
->max_huge_pages
;
3830 if (!hugepages_supported())
3833 ret
= proc_hugetlb_doulongvec_minmax(table
, write
, buffer
, length
, ppos
,
3839 ret
= __nr_hugepages_store_common(obey_mempolicy
, h
,
3840 NUMA_NO_NODE
, tmp
, *length
);
3845 int hugetlb_sysctl_handler(struct ctl_table
*table
, int write
,
3846 void *buffer
, size_t *length
, loff_t
*ppos
)
3849 return hugetlb_sysctl_handler_common(false, table
, write
,
3850 buffer
, length
, ppos
);
3854 int hugetlb_mempolicy_sysctl_handler(struct ctl_table
*table
, int write
,
3855 void *buffer
, size_t *length
, loff_t
*ppos
)
3857 return hugetlb_sysctl_handler_common(true, table
, write
,
3858 buffer
, length
, ppos
);
3860 #endif /* CONFIG_NUMA */
3862 int hugetlb_overcommit_handler(struct ctl_table
*table
, int write
,
3863 void *buffer
, size_t *length
, loff_t
*ppos
)
3865 struct hstate
*h
= &default_hstate
;
3869 if (!hugepages_supported())
3872 tmp
= h
->nr_overcommit_huge_pages
;
3874 if (write
&& hstate_is_gigantic(h
))
3877 ret
= proc_hugetlb_doulongvec_minmax(table
, write
, buffer
, length
, ppos
,
3883 spin_lock_irq(&hugetlb_lock
);
3884 h
->nr_overcommit_huge_pages
= tmp
;
3885 spin_unlock_irq(&hugetlb_lock
);
3891 #endif /* CONFIG_SYSCTL */
3893 void hugetlb_report_meminfo(struct seq_file
*m
)
3896 unsigned long total
= 0;
3898 if (!hugepages_supported())
3901 for_each_hstate(h
) {
3902 unsigned long count
= h
->nr_huge_pages
;
3904 total
+= huge_page_size(h
) * count
;
3906 if (h
== &default_hstate
)
3908 "HugePages_Total: %5lu\n"
3909 "HugePages_Free: %5lu\n"
3910 "HugePages_Rsvd: %5lu\n"
3911 "HugePages_Surp: %5lu\n"
3912 "Hugepagesize: %8lu kB\n",
3916 h
->surplus_huge_pages
,
3917 huge_page_size(h
) / SZ_1K
);
3920 seq_printf(m
, "Hugetlb: %8lu kB\n", total
/ SZ_1K
);
3923 int hugetlb_report_node_meminfo(char *buf
, int len
, int nid
)
3925 struct hstate
*h
= &default_hstate
;
3927 if (!hugepages_supported())
3930 return sysfs_emit_at(buf
, len
,
3931 "Node %d HugePages_Total: %5u\n"
3932 "Node %d HugePages_Free: %5u\n"
3933 "Node %d HugePages_Surp: %5u\n",
3934 nid
, h
->nr_huge_pages_node
[nid
],
3935 nid
, h
->free_huge_pages_node
[nid
],
3936 nid
, h
->surplus_huge_pages_node
[nid
]);
3939 void hugetlb_show_meminfo(void)
3944 if (!hugepages_supported())
3947 for_each_node_state(nid
, N_MEMORY
)
3949 pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n",
3951 h
->nr_huge_pages_node
[nid
],
3952 h
->free_huge_pages_node
[nid
],
3953 h
->surplus_huge_pages_node
[nid
],
3954 huge_page_size(h
) / SZ_1K
);
3957 void hugetlb_report_usage(struct seq_file
*m
, struct mm_struct
*mm
)
3959 seq_printf(m
, "HugetlbPages:\t%8lu kB\n",
3960 atomic_long_read(&mm
->hugetlb_usage
) << (PAGE_SHIFT
- 10));
3963 /* Return the number pages of memory we physically have, in PAGE_SIZE units. */
3964 unsigned long hugetlb_total_pages(void)
3967 unsigned long nr_total_pages
= 0;
3970 nr_total_pages
+= h
->nr_huge_pages
* pages_per_huge_page(h
);
3971 return nr_total_pages
;
3974 static int hugetlb_acct_memory(struct hstate
*h
, long delta
)
3981 spin_lock_irq(&hugetlb_lock
);
3983 * When cpuset is configured, it breaks the strict hugetlb page
3984 * reservation as the accounting is done on a global variable. Such
3985 * reservation is completely rubbish in the presence of cpuset because
3986 * the reservation is not checked against page availability for the
3987 * current cpuset. Application can still potentially OOM'ed by kernel
3988 * with lack of free htlb page in cpuset that the task is in.
3989 * Attempt to enforce strict accounting with cpuset is almost
3990 * impossible (or too ugly) because cpuset is too fluid that
3991 * task or memory node can be dynamically moved between cpusets.
3993 * The change of semantics for shared hugetlb mapping with cpuset is
3994 * undesirable. However, in order to preserve some of the semantics,
3995 * we fall back to check against current free page availability as
3996 * a best attempt and hopefully to minimize the impact of changing
3997 * semantics that cpuset has.
3999 * Apart from cpuset, we also have memory policy mechanism that
4000 * also determines from which node the kernel will allocate memory
4001 * in a NUMA system. So similar to cpuset, we also should consider
4002 * the memory policy of the current task. Similar to the description
4006 if (gather_surplus_pages(h
, delta
) < 0)
4009 if (delta
> allowed_mems_nr(h
)) {
4010 return_unused_surplus_pages(h
, delta
);
4017 return_unused_surplus_pages(h
, (unsigned long) -delta
);
4020 spin_unlock_irq(&hugetlb_lock
);
4024 static void hugetlb_vm_op_open(struct vm_area_struct
*vma
)
4026 struct resv_map
*resv
= vma_resv_map(vma
);
4029 * This new VMA should share its siblings reservation map if present.
4030 * The VMA will only ever have a valid reservation map pointer where
4031 * it is being copied for another still existing VMA. As that VMA
4032 * has a reference to the reservation map it cannot disappear until
4033 * after this open call completes. It is therefore safe to take a
4034 * new reference here without additional locking.
4036 if (resv
&& is_vma_resv_set(vma
, HPAGE_RESV_OWNER
))
4037 kref_get(&resv
->refs
);
4040 static void hugetlb_vm_op_close(struct vm_area_struct
*vma
)
4042 struct hstate
*h
= hstate_vma(vma
);
4043 struct resv_map
*resv
= vma_resv_map(vma
);
4044 struct hugepage_subpool
*spool
= subpool_vma(vma
);
4045 unsigned long reserve
, start
, end
;
4048 if (!resv
|| !is_vma_resv_set(vma
, HPAGE_RESV_OWNER
))
4051 start
= vma_hugecache_offset(h
, vma
, vma
->vm_start
);
4052 end
= vma_hugecache_offset(h
, vma
, vma
->vm_end
);
4054 reserve
= (end
- start
) - region_count(resv
, start
, end
);
4055 hugetlb_cgroup_uncharge_counter(resv
, start
, end
);
4058 * Decrement reserve counts. The global reserve count may be
4059 * adjusted if the subpool has a minimum size.
4061 gbl_reserve
= hugepage_subpool_put_pages(spool
, reserve
);
4062 hugetlb_acct_memory(h
, -gbl_reserve
);
4065 kref_put(&resv
->refs
, resv_map_release
);
4068 static int hugetlb_vm_op_split(struct vm_area_struct
*vma
, unsigned long addr
)
4070 if (addr
& ~(huge_page_mask(hstate_vma(vma
))))
4075 static unsigned long hugetlb_vm_op_pagesize(struct vm_area_struct
*vma
)
4077 return huge_page_size(hstate_vma(vma
));
4081 * We cannot handle pagefaults against hugetlb pages at all. They cause
4082 * handle_mm_fault() to try to instantiate regular-sized pages in the
4083 * hugepage VMA. do_page_fault() is supposed to trap this, so BUG is we get
4086 static vm_fault_t
hugetlb_vm_op_fault(struct vm_fault
*vmf
)
4093 * When a new function is introduced to vm_operations_struct and added
4094 * to hugetlb_vm_ops, please consider adding the function to shm_vm_ops.
4095 * This is because under System V memory model, mappings created via
4096 * shmget/shmat with "huge page" specified are backed by hugetlbfs files,
4097 * their original vm_ops are overwritten with shm_vm_ops.
4099 const struct vm_operations_struct hugetlb_vm_ops
= {
4100 .fault
= hugetlb_vm_op_fault
,
4101 .open
= hugetlb_vm_op_open
,
4102 .close
= hugetlb_vm_op_close
,
4103 .may_split
= hugetlb_vm_op_split
,
4104 .pagesize
= hugetlb_vm_op_pagesize
,
4107 static pte_t
make_huge_pte(struct vm_area_struct
*vma
, struct page
*page
,
4111 unsigned int shift
= huge_page_shift(hstate_vma(vma
));
4114 entry
= huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page
,
4115 vma
->vm_page_prot
)));
4117 entry
= huge_pte_wrprotect(mk_huge_pte(page
,
4118 vma
->vm_page_prot
));
4120 entry
= pte_mkyoung(entry
);
4121 entry
= pte_mkhuge(entry
);
4122 entry
= arch_make_huge_pte(entry
, shift
, vma
->vm_flags
);
4127 static void set_huge_ptep_writable(struct vm_area_struct
*vma
,
4128 unsigned long address
, pte_t
*ptep
)
4132 entry
= huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep
)));
4133 if (huge_ptep_set_access_flags(vma
, address
, ptep
, entry
, 1))
4134 update_mmu_cache(vma
, address
, ptep
);
4137 bool is_hugetlb_entry_migration(pte_t pte
)
4141 if (huge_pte_none(pte
) || pte_present(pte
))
4143 swp
= pte_to_swp_entry(pte
);
4144 if (is_migration_entry(swp
))
4150 static bool is_hugetlb_entry_hwpoisoned(pte_t pte
)
4154 if (huge_pte_none(pte
) || pte_present(pte
))
4156 swp
= pte_to_swp_entry(pte
);
4157 if (is_hwpoison_entry(swp
))
4164 hugetlb_install_page(struct vm_area_struct
*vma
, pte_t
*ptep
, unsigned long addr
,
4165 struct page
*new_page
)
4167 __SetPageUptodate(new_page
);
4168 set_huge_pte_at(vma
->vm_mm
, addr
, ptep
, make_huge_pte(vma
, new_page
, 1));
4169 hugepage_add_new_anon_rmap(new_page
, vma
, addr
);
4170 hugetlb_count_add(pages_per_huge_page(hstate_vma(vma
)), vma
->vm_mm
);
4171 ClearHPageRestoreReserve(new_page
);
4172 SetHPageMigratable(new_page
);
4175 int copy_hugetlb_page_range(struct mm_struct
*dst
, struct mm_struct
*src
,
4176 struct vm_area_struct
*vma
)
4178 pte_t
*src_pte
, *dst_pte
, entry
, dst_entry
;
4179 struct page
*ptepage
;
4181 bool cow
= is_cow_mapping(vma
->vm_flags
);
4182 struct hstate
*h
= hstate_vma(vma
);
4183 unsigned long sz
= huge_page_size(h
);
4184 unsigned long npages
= pages_per_huge_page(h
);
4185 struct address_space
*mapping
= vma
->vm_file
->f_mapping
;
4186 struct mmu_notifier_range range
;
4190 mmu_notifier_range_init(&range
, MMU_NOTIFY_CLEAR
, 0, vma
, src
,
4193 mmu_notifier_invalidate_range_start(&range
);
4196 * For shared mappings i_mmap_rwsem must be held to call
4197 * huge_pte_alloc, otherwise the returned ptep could go
4198 * away if part of a shared pmd and another thread calls
4201 i_mmap_lock_read(mapping
);
4204 for (addr
= vma
->vm_start
; addr
< vma
->vm_end
; addr
+= sz
) {
4205 spinlock_t
*src_ptl
, *dst_ptl
;
4206 src_pte
= huge_pte_offset(src
, addr
, sz
);
4209 dst_pte
= huge_pte_alloc(dst
, vma
, addr
, sz
);
4216 * If the pagetables are shared don't copy or take references.
4217 * dst_pte == src_pte is the common case of src/dest sharing.
4219 * However, src could have 'unshared' and dst shares with
4220 * another vma. If dst_pte !none, this implies sharing.
4221 * Check here before taking page table lock, and once again
4222 * after taking the lock below.
4224 dst_entry
= huge_ptep_get(dst_pte
);
4225 if ((dst_pte
== src_pte
) || !huge_pte_none(dst_entry
))
4228 dst_ptl
= huge_pte_lock(h
, dst
, dst_pte
);
4229 src_ptl
= huge_pte_lockptr(h
, src
, src_pte
);
4230 spin_lock_nested(src_ptl
, SINGLE_DEPTH_NESTING
);
4231 entry
= huge_ptep_get(src_pte
);
4232 dst_entry
= huge_ptep_get(dst_pte
);
4234 if (huge_pte_none(entry
) || !huge_pte_none(dst_entry
)) {
4236 * Skip if src entry none. Also, skip in the
4237 * unlikely case dst entry !none as this implies
4238 * sharing with another vma.
4241 } else if (unlikely(is_hugetlb_entry_migration(entry
) ||
4242 is_hugetlb_entry_hwpoisoned(entry
))) {
4243 swp_entry_t swp_entry
= pte_to_swp_entry(entry
);
4245 if (is_writable_migration_entry(swp_entry
) && cow
) {
4247 * COW mappings require pages in both
4248 * parent and child to be set to read.
4250 swp_entry
= make_readable_migration_entry(
4251 swp_offset(swp_entry
));
4252 entry
= swp_entry_to_pte(swp_entry
);
4253 set_huge_swap_pte_at(src
, addr
, src_pte
,
4256 set_huge_swap_pte_at(dst
, addr
, dst_pte
, entry
, sz
);
4258 entry
= huge_ptep_get(src_pte
);
4259 ptepage
= pte_page(entry
);
4263 * This is a rare case where we see pinned hugetlb
4264 * pages while they're prone to COW. We need to do the
4265 * COW earlier during fork.
4267 * When pre-allocating the page or copying data, we
4268 * need to be without the pgtable locks since we could
4269 * sleep during the process.
4271 if (unlikely(page_needs_cow_for_dma(vma
, ptepage
))) {
4272 pte_t src_pte_old
= entry
;
4275 spin_unlock(src_ptl
);
4276 spin_unlock(dst_ptl
);
4277 /* Do not use reserve as it's private owned */
4278 new = alloc_huge_page(vma
, addr
, 1);
4284 copy_user_huge_page(new, ptepage
, addr
, vma
,
4288 /* Install the new huge page if src pte stable */
4289 dst_ptl
= huge_pte_lock(h
, dst
, dst_pte
);
4290 src_ptl
= huge_pte_lockptr(h
, src
, src_pte
);
4291 spin_lock_nested(src_ptl
, SINGLE_DEPTH_NESTING
);
4292 entry
= huge_ptep_get(src_pte
);
4293 if (!pte_same(src_pte_old
, entry
)) {
4294 restore_reserve_on_error(h
, vma
, addr
,
4297 /* dst_entry won't change as in child */
4300 hugetlb_install_page(vma
, dst_pte
, addr
, new);
4301 spin_unlock(src_ptl
);
4302 spin_unlock(dst_ptl
);
4308 * No need to notify as we are downgrading page
4309 * table protection not changing it to point
4312 * See Documentation/vm/mmu_notifier.rst
4314 huge_ptep_set_wrprotect(src
, addr
, src_pte
);
4315 entry
= huge_pte_wrprotect(entry
);
4318 page_dup_rmap(ptepage
, true);
4319 set_huge_pte_at(dst
, addr
, dst_pte
, entry
);
4320 hugetlb_count_add(npages
, dst
);
4322 spin_unlock(src_ptl
);
4323 spin_unlock(dst_ptl
);
4327 mmu_notifier_invalidate_range_end(&range
);
4329 i_mmap_unlock_read(mapping
);
4334 void __unmap_hugepage_range(struct mmu_gather
*tlb
, struct vm_area_struct
*vma
,
4335 unsigned long start
, unsigned long end
,
4336 struct page
*ref_page
)
4338 struct mm_struct
*mm
= vma
->vm_mm
;
4339 unsigned long address
;
4344 struct hstate
*h
= hstate_vma(vma
);
4345 unsigned long sz
= huge_page_size(h
);
4346 struct mmu_notifier_range range
;
4348 WARN_ON(!is_vm_hugetlb_page(vma
));
4349 BUG_ON(start
& ~huge_page_mask(h
));
4350 BUG_ON(end
& ~huge_page_mask(h
));
4353 * This is a hugetlb vma, all the pte entries should point
4356 tlb_change_page_size(tlb
, sz
);
4357 tlb_start_vma(tlb
, vma
);
4360 * If sharing possible, alert mmu notifiers of worst case.
4362 mmu_notifier_range_init(&range
, MMU_NOTIFY_UNMAP
, 0, vma
, mm
, start
,
4364 adjust_range_if_pmd_sharing_possible(vma
, &range
.start
, &range
.end
);
4365 mmu_notifier_invalidate_range_start(&range
);
4367 for (; address
< end
; address
+= sz
) {
4368 ptep
= huge_pte_offset(mm
, address
, sz
);
4372 ptl
= huge_pte_lock(h
, mm
, ptep
);
4373 if (huge_pmd_unshare(mm
, vma
, &address
, ptep
)) {
4376 * We just unmapped a page of PMDs by clearing a PUD.
4377 * The caller's TLB flush range should cover this area.
4382 pte
= huge_ptep_get(ptep
);
4383 if (huge_pte_none(pte
)) {
4389 * Migrating hugepage or HWPoisoned hugepage is already
4390 * unmapped and its refcount is dropped, so just clear pte here.
4392 if (unlikely(!pte_present(pte
))) {
4393 huge_pte_clear(mm
, address
, ptep
, sz
);
4398 page
= pte_page(pte
);
4400 * If a reference page is supplied, it is because a specific
4401 * page is being unmapped, not a range. Ensure the page we
4402 * are about to unmap is the actual page of interest.
4405 if (page
!= ref_page
) {
4410 * Mark the VMA as having unmapped its page so that
4411 * future faults in this VMA will fail rather than
4412 * looking like data was lost
4414 set_vma_resv_flags(vma
, HPAGE_RESV_UNMAPPED
);
4417 pte
= huge_ptep_get_and_clear(mm
, address
, ptep
);
4418 tlb_remove_huge_tlb_entry(h
, tlb
, ptep
, address
);
4419 if (huge_pte_dirty(pte
))
4420 set_page_dirty(page
);
4422 hugetlb_count_sub(pages_per_huge_page(h
), mm
);
4423 page_remove_rmap(page
, true);
4426 tlb_remove_page_size(tlb
, page
, huge_page_size(h
));
4428 * Bail out after unmapping reference page if supplied
4433 mmu_notifier_invalidate_range_end(&range
);
4434 tlb_end_vma(tlb
, vma
);
4437 void __unmap_hugepage_range_final(struct mmu_gather
*tlb
,
4438 struct vm_area_struct
*vma
, unsigned long start
,
4439 unsigned long end
, struct page
*ref_page
)
4441 __unmap_hugepage_range(tlb
, vma
, start
, end
, ref_page
);
4444 * Clear this flag so that x86's huge_pmd_share page_table_shareable
4445 * test will fail on a vma being torn down, and not grab a page table
4446 * on its way out. We're lucky that the flag has such an appropriate
4447 * name, and can in fact be safely cleared here. We could clear it
4448 * before the __unmap_hugepage_range above, but all that's necessary
4449 * is to clear it before releasing the i_mmap_rwsem. This works
4450 * because in the context this is called, the VMA is about to be
4451 * destroyed and the i_mmap_rwsem is held.
4453 vma
->vm_flags
&= ~VM_MAYSHARE
;
4456 void unmap_hugepage_range(struct vm_area_struct
*vma
, unsigned long start
,
4457 unsigned long end
, struct page
*ref_page
)
4459 struct mmu_gather tlb
;
4461 tlb_gather_mmu(&tlb
, vma
->vm_mm
);
4462 __unmap_hugepage_range(&tlb
, vma
, start
, end
, ref_page
);
4463 tlb_finish_mmu(&tlb
);
4467 * This is called when the original mapper is failing to COW a MAP_PRIVATE
4468 * mapping it owns the reserve page for. The intention is to unmap the page
4469 * from other VMAs and let the children be SIGKILLed if they are faulting the
4472 static void unmap_ref_private(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
4473 struct page
*page
, unsigned long address
)
4475 struct hstate
*h
= hstate_vma(vma
);
4476 struct vm_area_struct
*iter_vma
;
4477 struct address_space
*mapping
;
4481 * vm_pgoff is in PAGE_SIZE units, hence the different calculation
4482 * from page cache lookup which is in HPAGE_SIZE units.
4484 address
= address
& huge_page_mask(h
);
4485 pgoff
= ((address
- vma
->vm_start
) >> PAGE_SHIFT
) +
4487 mapping
= vma
->vm_file
->f_mapping
;
4490 * Take the mapping lock for the duration of the table walk. As
4491 * this mapping should be shared between all the VMAs,
4492 * __unmap_hugepage_range() is called as the lock is already held
4494 i_mmap_lock_write(mapping
);
4495 vma_interval_tree_foreach(iter_vma
, &mapping
->i_mmap
, pgoff
, pgoff
) {
4496 /* Do not unmap the current VMA */
4497 if (iter_vma
== vma
)
4501 * Shared VMAs have their own reserves and do not affect
4502 * MAP_PRIVATE accounting but it is possible that a shared
4503 * VMA is using the same page so check and skip such VMAs.
4505 if (iter_vma
->vm_flags
& VM_MAYSHARE
)
4509 * Unmap the page from other VMAs without their own reserves.
4510 * They get marked to be SIGKILLed if they fault in these
4511 * areas. This is because a future no-page fault on this VMA
4512 * could insert a zeroed page instead of the data existing
4513 * from the time of fork. This would look like data corruption
4515 if (!is_vma_resv_set(iter_vma
, HPAGE_RESV_OWNER
))
4516 unmap_hugepage_range(iter_vma
, address
,
4517 address
+ huge_page_size(h
), page
);
4519 i_mmap_unlock_write(mapping
);
4523 * Hugetlb_cow() should be called with page lock of the original hugepage held.
4524 * Called with hugetlb_instantiation_mutex held and pte_page locked so we
4525 * cannot race with other handlers or page migration.
4526 * Keep the pte_same checks anyway to make transition from the mutex easier.
4528 static vm_fault_t
hugetlb_cow(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
4529 unsigned long address
, pte_t
*ptep
,
4530 struct page
*pagecache_page
, spinlock_t
*ptl
)
4533 struct hstate
*h
= hstate_vma(vma
);
4534 struct page
*old_page
, *new_page
;
4535 int outside_reserve
= 0;
4537 unsigned long haddr
= address
& huge_page_mask(h
);
4538 struct mmu_notifier_range range
;
4540 pte
= huge_ptep_get(ptep
);
4541 old_page
= pte_page(pte
);
4544 /* If no-one else is actually using this page, avoid the copy
4545 * and just make the page writable */
4546 if (page_mapcount(old_page
) == 1 && PageAnon(old_page
)) {
4547 page_move_anon_rmap(old_page
, vma
);
4548 set_huge_ptep_writable(vma
, haddr
, ptep
);
4553 * If the process that created a MAP_PRIVATE mapping is about to
4554 * perform a COW due to a shared page count, attempt to satisfy
4555 * the allocation without using the existing reserves. The pagecache
4556 * page is used to determine if the reserve at this address was
4557 * consumed or not. If reserves were used, a partial faulted mapping
4558 * at the time of fork() could consume its reserves on COW instead
4559 * of the full address range.
4561 if (is_vma_resv_set(vma
, HPAGE_RESV_OWNER
) &&
4562 old_page
!= pagecache_page
)
4563 outside_reserve
= 1;
4568 * Drop page table lock as buddy allocator may be called. It will
4569 * be acquired again before returning to the caller, as expected.
4572 new_page
= alloc_huge_page(vma
, haddr
, outside_reserve
);
4574 if (IS_ERR(new_page
)) {
4576 * If a process owning a MAP_PRIVATE mapping fails to COW,
4577 * it is due to references held by a child and an insufficient
4578 * huge page pool. To guarantee the original mappers
4579 * reliability, unmap the page from child processes. The child
4580 * may get SIGKILLed if it later faults.
4582 if (outside_reserve
) {
4583 struct address_space
*mapping
= vma
->vm_file
->f_mapping
;
4588 BUG_ON(huge_pte_none(pte
));
4590 * Drop hugetlb_fault_mutex and i_mmap_rwsem before
4591 * unmapping. unmapping needs to hold i_mmap_rwsem
4592 * in write mode. Dropping i_mmap_rwsem in read mode
4593 * here is OK as COW mappings do not interact with
4596 * Reacquire both after unmap operation.
4598 idx
= vma_hugecache_offset(h
, vma
, haddr
);
4599 hash
= hugetlb_fault_mutex_hash(mapping
, idx
);
4600 mutex_unlock(&hugetlb_fault_mutex_table
[hash
]);
4601 i_mmap_unlock_read(mapping
);
4603 unmap_ref_private(mm
, vma
, old_page
, haddr
);
4605 i_mmap_lock_read(mapping
);
4606 mutex_lock(&hugetlb_fault_mutex_table
[hash
]);
4608 ptep
= huge_pte_offset(mm
, haddr
, huge_page_size(h
));
4610 pte_same(huge_ptep_get(ptep
), pte
)))
4611 goto retry_avoidcopy
;
4613 * race occurs while re-acquiring page table
4614 * lock, and our job is done.
4619 ret
= vmf_error(PTR_ERR(new_page
));
4620 goto out_release_old
;
4624 * When the original hugepage is shared one, it does not have
4625 * anon_vma prepared.
4627 if (unlikely(anon_vma_prepare(vma
))) {
4629 goto out_release_all
;
4632 copy_user_huge_page(new_page
, old_page
, address
, vma
,
4633 pages_per_huge_page(h
));
4634 __SetPageUptodate(new_page
);
4636 mmu_notifier_range_init(&range
, MMU_NOTIFY_CLEAR
, 0, vma
, mm
, haddr
,
4637 haddr
+ huge_page_size(h
));
4638 mmu_notifier_invalidate_range_start(&range
);
4641 * Retake the page table lock to check for racing updates
4642 * before the page tables are altered
4645 ptep
= huge_pte_offset(mm
, haddr
, huge_page_size(h
));
4646 if (likely(ptep
&& pte_same(huge_ptep_get(ptep
), pte
))) {
4647 ClearHPageRestoreReserve(new_page
);
4650 huge_ptep_clear_flush(vma
, haddr
, ptep
);
4651 mmu_notifier_invalidate_range(mm
, range
.start
, range
.end
);
4652 set_huge_pte_at(mm
, haddr
, ptep
,
4653 make_huge_pte(vma
, new_page
, 1));
4654 page_remove_rmap(old_page
, true);
4655 hugepage_add_new_anon_rmap(new_page
, vma
, haddr
);
4656 SetHPageMigratable(new_page
);
4657 /* Make the old page be freed below */
4658 new_page
= old_page
;
4661 mmu_notifier_invalidate_range_end(&range
);
4663 restore_reserve_on_error(h
, vma
, haddr
, new_page
);
4668 spin_lock(ptl
); /* Caller expects lock to be held */
4672 /* Return the pagecache page at a given address within a VMA */
4673 static struct page
*hugetlbfs_pagecache_page(struct hstate
*h
,
4674 struct vm_area_struct
*vma
, unsigned long address
)
4676 struct address_space
*mapping
;
4679 mapping
= vma
->vm_file
->f_mapping
;
4680 idx
= vma_hugecache_offset(h
, vma
, address
);
4682 return find_lock_page(mapping
, idx
);
4686 * Return whether there is a pagecache page to back given address within VMA.
4687 * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page.
4689 static bool hugetlbfs_pagecache_present(struct hstate
*h
,
4690 struct vm_area_struct
*vma
, unsigned long address
)
4692 struct address_space
*mapping
;
4696 mapping
= vma
->vm_file
->f_mapping
;
4697 idx
= vma_hugecache_offset(h
, vma
, address
);
4699 page
= find_get_page(mapping
, idx
);
4702 return page
!= NULL
;
4705 int huge_add_to_page_cache(struct page
*page
, struct address_space
*mapping
,
4708 struct inode
*inode
= mapping
->host
;
4709 struct hstate
*h
= hstate_inode(inode
);
4710 int err
= add_to_page_cache(page
, mapping
, idx
, GFP_KERNEL
);
4714 ClearHPageRestoreReserve(page
);
4717 * set page dirty so that it will not be removed from cache/file
4718 * by non-hugetlbfs specific code paths.
4720 set_page_dirty(page
);
4722 spin_lock(&inode
->i_lock
);
4723 inode
->i_blocks
+= blocks_per_huge_page(h
);
4724 spin_unlock(&inode
->i_lock
);
4728 static inline vm_fault_t
hugetlb_handle_userfault(struct vm_area_struct
*vma
,
4729 struct address_space
*mapping
,
4732 unsigned long haddr
,
4733 unsigned long reason
)
4737 struct vm_fault vmf
= {
4743 * Hard to debug if it ends up being
4744 * used by a callee that assumes
4745 * something about the other
4746 * uninitialized fields... same as in
4752 * hugetlb_fault_mutex and i_mmap_rwsem must be
4753 * dropped before handling userfault. Reacquire
4754 * after handling fault to make calling code simpler.
4756 hash
= hugetlb_fault_mutex_hash(mapping
, idx
);
4757 mutex_unlock(&hugetlb_fault_mutex_table
[hash
]);
4758 i_mmap_unlock_read(mapping
);
4759 ret
= handle_userfault(&vmf
, reason
);
4760 i_mmap_lock_read(mapping
);
4761 mutex_lock(&hugetlb_fault_mutex_table
[hash
]);
4766 static vm_fault_t
hugetlb_no_page(struct mm_struct
*mm
,
4767 struct vm_area_struct
*vma
,
4768 struct address_space
*mapping
, pgoff_t idx
,
4769 unsigned long address
, pte_t
*ptep
, unsigned int flags
)
4771 struct hstate
*h
= hstate_vma(vma
);
4772 vm_fault_t ret
= VM_FAULT_SIGBUS
;
4778 unsigned long haddr
= address
& huge_page_mask(h
);
4779 bool new_page
= false;
4782 * Currently, we are forced to kill the process in the event the
4783 * original mapper has unmapped pages from the child due to a failed
4784 * COW. Warn that such a situation has occurred as it may not be obvious
4786 if (is_vma_resv_set(vma
, HPAGE_RESV_UNMAPPED
)) {
4787 pr_warn_ratelimited("PID %d killed due to inadequate hugepage pool\n",
4793 * We can not race with truncation due to holding i_mmap_rwsem.
4794 * i_size is modified when holding i_mmap_rwsem, so check here
4795 * once for faults beyond end of file.
4797 size
= i_size_read(mapping
->host
) >> huge_page_shift(h
);
4802 page
= find_lock_page(mapping
, idx
);
4804 /* Check for page in userfault range */
4805 if (userfaultfd_missing(vma
)) {
4806 ret
= hugetlb_handle_userfault(vma
, mapping
, idx
,
4812 page
= alloc_huge_page(vma
, haddr
, 0);
4815 * Returning error will result in faulting task being
4816 * sent SIGBUS. The hugetlb fault mutex prevents two
4817 * tasks from racing to fault in the same page which
4818 * could result in false unable to allocate errors.
4819 * Page migration does not take the fault mutex, but
4820 * does a clear then write of pte's under page table
4821 * lock. Page fault code could race with migration,
4822 * notice the clear pte and try to allocate a page
4823 * here. Before returning error, get ptl and make
4824 * sure there really is no pte entry.
4826 ptl
= huge_pte_lock(h
, mm
, ptep
);
4828 if (huge_pte_none(huge_ptep_get(ptep
)))
4829 ret
= vmf_error(PTR_ERR(page
));
4833 clear_huge_page(page
, address
, pages_per_huge_page(h
));
4834 __SetPageUptodate(page
);
4837 if (vma
->vm_flags
& VM_MAYSHARE
) {
4838 int err
= huge_add_to_page_cache(page
, mapping
, idx
);
4847 if (unlikely(anon_vma_prepare(vma
))) {
4849 goto backout_unlocked
;
4855 * If memory error occurs between mmap() and fault, some process
4856 * don't have hwpoisoned swap entry for errored virtual address.
4857 * So we need to block hugepage fault by PG_hwpoison bit check.
4859 if (unlikely(PageHWPoison(page
))) {
4860 ret
= VM_FAULT_HWPOISON_LARGE
|
4861 VM_FAULT_SET_HINDEX(hstate_index(h
));
4862 goto backout_unlocked
;
4865 /* Check for page in userfault range. */
4866 if (userfaultfd_minor(vma
)) {
4869 ret
= hugetlb_handle_userfault(vma
, mapping
, idx
,
4877 * If we are going to COW a private mapping later, we examine the
4878 * pending reservations for this page now. This will ensure that
4879 * any allocations necessary to record that reservation occur outside
4882 if ((flags
& FAULT_FLAG_WRITE
) && !(vma
->vm_flags
& VM_SHARED
)) {
4883 if (vma_needs_reservation(h
, vma
, haddr
) < 0) {
4885 goto backout_unlocked
;
4887 /* Just decrements count, does not deallocate */
4888 vma_end_reservation(h
, vma
, haddr
);
4891 ptl
= huge_pte_lock(h
, mm
, ptep
);
4893 if (!huge_pte_none(huge_ptep_get(ptep
)))
4897 ClearHPageRestoreReserve(page
);
4898 hugepage_add_new_anon_rmap(page
, vma
, haddr
);
4900 page_dup_rmap(page
, true);
4901 new_pte
= make_huge_pte(vma
, page
, ((vma
->vm_flags
& VM_WRITE
)
4902 && (vma
->vm_flags
& VM_SHARED
)));
4903 set_huge_pte_at(mm
, haddr
, ptep
, new_pte
);
4905 hugetlb_count_add(pages_per_huge_page(h
), mm
);
4906 if ((flags
& FAULT_FLAG_WRITE
) && !(vma
->vm_flags
& VM_SHARED
)) {
4907 /* Optimization, do the COW without a second fault */
4908 ret
= hugetlb_cow(mm
, vma
, address
, ptep
, page
, ptl
);
4914 * Only set HPageMigratable in newly allocated pages. Existing pages
4915 * found in the pagecache may not have HPageMigratableset if they have
4916 * been isolated for migration.
4919 SetHPageMigratable(page
);
4929 restore_reserve_on_error(h
, vma
, haddr
, page
);
4935 u32
hugetlb_fault_mutex_hash(struct address_space
*mapping
, pgoff_t idx
)
4937 unsigned long key
[2];
4940 key
[0] = (unsigned long) mapping
;
4943 hash
= jhash2((u32
*)&key
, sizeof(key
)/(sizeof(u32
)), 0);
4945 return hash
& (num_fault_mutexes
- 1);
4949 * For uniprocessor systems we always use a single mutex, so just
4950 * return 0 and avoid the hashing overhead.
4952 u32
hugetlb_fault_mutex_hash(struct address_space
*mapping
, pgoff_t idx
)
4958 vm_fault_t
hugetlb_fault(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
4959 unsigned long address
, unsigned int flags
)
4966 struct page
*page
= NULL
;
4967 struct page
*pagecache_page
= NULL
;
4968 struct hstate
*h
= hstate_vma(vma
);
4969 struct address_space
*mapping
;
4970 int need_wait_lock
= 0;
4971 unsigned long haddr
= address
& huge_page_mask(h
);
4973 ptep
= huge_pte_offset(mm
, haddr
, huge_page_size(h
));
4976 * Since we hold no locks, ptep could be stale. That is
4977 * OK as we are only making decisions based on content and
4978 * not actually modifying content here.
4980 entry
= huge_ptep_get(ptep
);
4981 if (unlikely(is_hugetlb_entry_migration(entry
))) {
4982 migration_entry_wait_huge(vma
, mm
, ptep
);
4984 } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry
)))
4985 return VM_FAULT_HWPOISON_LARGE
|
4986 VM_FAULT_SET_HINDEX(hstate_index(h
));
4990 * Acquire i_mmap_rwsem before calling huge_pte_alloc and hold
4991 * until finished with ptep. This serves two purposes:
4992 * 1) It prevents huge_pmd_unshare from being called elsewhere
4993 * and making the ptep no longer valid.
4994 * 2) It synchronizes us with i_size modifications during truncation.
4996 * ptep could have already be assigned via huge_pte_offset. That
4997 * is OK, as huge_pte_alloc will return the same value unless
4998 * something has changed.
5000 mapping
= vma
->vm_file
->f_mapping
;
5001 i_mmap_lock_read(mapping
);
5002 ptep
= huge_pte_alloc(mm
, vma
, haddr
, huge_page_size(h
));
5004 i_mmap_unlock_read(mapping
);
5005 return VM_FAULT_OOM
;
5009 * Serialize hugepage allocation and instantiation, so that we don't
5010 * get spurious allocation failures if two CPUs race to instantiate
5011 * the same page in the page cache.
5013 idx
= vma_hugecache_offset(h
, vma
, haddr
);
5014 hash
= hugetlb_fault_mutex_hash(mapping
, idx
);
5015 mutex_lock(&hugetlb_fault_mutex_table
[hash
]);
5017 entry
= huge_ptep_get(ptep
);
5018 if (huge_pte_none(entry
)) {
5019 ret
= hugetlb_no_page(mm
, vma
, mapping
, idx
, address
, ptep
, flags
);
5026 * entry could be a migration/hwpoison entry at this point, so this
5027 * check prevents the kernel from going below assuming that we have
5028 * an active hugepage in pagecache. This goto expects the 2nd page
5029 * fault, and is_hugetlb_entry_(migration|hwpoisoned) check will
5030 * properly handle it.
5032 if (!pte_present(entry
))
5036 * If we are going to COW the mapping later, we examine the pending
5037 * reservations for this page now. This will ensure that any
5038 * allocations necessary to record that reservation occur outside the
5039 * spinlock. For private mappings, we also lookup the pagecache
5040 * page now as it is used to determine if a reservation has been
5043 if ((flags
& FAULT_FLAG_WRITE
) && !huge_pte_write(entry
)) {
5044 if (vma_needs_reservation(h
, vma
, haddr
) < 0) {
5048 /* Just decrements count, does not deallocate */
5049 vma_end_reservation(h
, vma
, haddr
);
5051 if (!(vma
->vm_flags
& VM_MAYSHARE
))
5052 pagecache_page
= hugetlbfs_pagecache_page(h
,
5056 ptl
= huge_pte_lock(h
, mm
, ptep
);
5058 /* Check for a racing update before calling hugetlb_cow */
5059 if (unlikely(!pte_same(entry
, huge_ptep_get(ptep
))))
5063 * hugetlb_cow() requires page locks of pte_page(entry) and
5064 * pagecache_page, so here we need take the former one
5065 * when page != pagecache_page or !pagecache_page.
5067 page
= pte_page(entry
);
5068 if (page
!= pagecache_page
)
5069 if (!trylock_page(page
)) {
5076 if (flags
& FAULT_FLAG_WRITE
) {
5077 if (!huge_pte_write(entry
)) {
5078 ret
= hugetlb_cow(mm
, vma
, address
, ptep
,
5079 pagecache_page
, ptl
);
5082 entry
= huge_pte_mkdirty(entry
);
5084 entry
= pte_mkyoung(entry
);
5085 if (huge_ptep_set_access_flags(vma
, haddr
, ptep
, entry
,
5086 flags
& FAULT_FLAG_WRITE
))
5087 update_mmu_cache(vma
, haddr
, ptep
);
5089 if (page
!= pagecache_page
)
5095 if (pagecache_page
) {
5096 unlock_page(pagecache_page
);
5097 put_page(pagecache_page
);
5100 mutex_unlock(&hugetlb_fault_mutex_table
[hash
]);
5101 i_mmap_unlock_read(mapping
);
5103 * Generally it's safe to hold refcount during waiting page lock. But
5104 * here we just wait to defer the next page fault to avoid busy loop and
5105 * the page is not used after unlocked before returning from the current
5106 * page fault. So we are safe from accessing freed page, even if we wait
5107 * here without taking refcount.
5110 wait_on_page_locked(page
);
5114 #ifdef CONFIG_USERFAULTFD
5116 * Used by userfaultfd UFFDIO_COPY. Based on mcopy_atomic_pte with
5117 * modifications for huge pages.
5119 int hugetlb_mcopy_atomic_pte(struct mm_struct
*dst_mm
,
5121 struct vm_area_struct
*dst_vma
,
5122 unsigned long dst_addr
,
5123 unsigned long src_addr
,
5124 enum mcopy_atomic_mode mode
,
5125 struct page
**pagep
)
5127 bool is_continue
= (mode
== MCOPY_ATOMIC_CONTINUE
);
5128 struct hstate
*h
= hstate_vma(dst_vma
);
5129 struct address_space
*mapping
= dst_vma
->vm_file
->f_mapping
;
5130 pgoff_t idx
= vma_hugecache_offset(h
, dst_vma
, dst_addr
);
5132 int vm_shared
= dst_vma
->vm_flags
& VM_SHARED
;
5141 page
= find_lock_page(mapping
, idx
);
5144 } else if (!*pagep
) {
5145 /* If a page already exists, then it's UFFDIO_COPY for
5146 * a non-missing case. Return -EEXIST.
5149 hugetlbfs_pagecache_present(h
, dst_vma
, dst_addr
)) {
5154 page
= alloc_huge_page(dst_vma
, dst_addr
, 0);
5160 ret
= copy_huge_page_from_user(page
,
5161 (const void __user
*) src_addr
,
5162 pages_per_huge_page(h
), false);
5164 /* fallback to copy_from_user outside mmap_lock */
5165 if (unlikely(ret
)) {
5167 /* Free the allocated page which may have
5168 * consumed a reservation.
5170 restore_reserve_on_error(h
, dst_vma
, dst_addr
, page
);
5173 /* Allocate a temporary page to hold the copied
5176 page
= alloc_huge_page_vma(h
, dst_vma
, dst_addr
);
5182 /* Set the outparam pagep and return to the caller to
5183 * copy the contents outside the lock. Don't free the
5190 hugetlbfs_pagecache_present(h
, dst_vma
, dst_addr
)) {
5197 page
= alloc_huge_page(dst_vma
, dst_addr
, 0);
5203 copy_huge_page(page
, *pagep
);
5209 * The memory barrier inside __SetPageUptodate makes sure that
5210 * preceding stores to the page contents become visible before
5211 * the set_pte_at() write.
5213 __SetPageUptodate(page
);
5215 /* Add shared, newly allocated pages to the page cache. */
5216 if (vm_shared
&& !is_continue
) {
5217 size
= i_size_read(mapping
->host
) >> huge_page_shift(h
);
5220 goto out_release_nounlock
;
5223 * Serialization between remove_inode_hugepages() and
5224 * huge_add_to_page_cache() below happens through the
5225 * hugetlb_fault_mutex_table that here must be hold by
5228 ret
= huge_add_to_page_cache(page
, mapping
, idx
);
5230 goto out_release_nounlock
;
5233 ptl
= huge_pte_lockptr(h
, dst_mm
, dst_pte
);
5237 * Recheck the i_size after holding PT lock to make sure not
5238 * to leave any page mapped (as page_mapped()) beyond the end
5239 * of the i_size (remove_inode_hugepages() is strict about
5240 * enforcing that). If we bail out here, we'll also leave a
5241 * page in the radix tree in the vm_shared case beyond the end
5242 * of the i_size, but remove_inode_hugepages() will take care
5243 * of it as soon as we drop the hugetlb_fault_mutex_table.
5245 size
= i_size_read(mapping
->host
) >> huge_page_shift(h
);
5248 goto out_release_unlock
;
5251 if (!huge_pte_none(huge_ptep_get(dst_pte
)))
5252 goto out_release_unlock
;
5255 page_dup_rmap(page
, true);
5257 ClearHPageRestoreReserve(page
);
5258 hugepage_add_new_anon_rmap(page
, dst_vma
, dst_addr
);
5261 /* For CONTINUE on a non-shared VMA, don't set VM_WRITE for CoW. */
5262 if (is_continue
&& !vm_shared
)
5265 writable
= dst_vma
->vm_flags
& VM_WRITE
;
5267 _dst_pte
= make_huge_pte(dst_vma
, page
, writable
);
5269 _dst_pte
= huge_pte_mkdirty(_dst_pte
);
5270 _dst_pte
= pte_mkyoung(_dst_pte
);
5272 set_huge_pte_at(dst_mm
, dst_addr
, dst_pte
, _dst_pte
);
5274 (void)huge_ptep_set_access_flags(dst_vma
, dst_addr
, dst_pte
, _dst_pte
,
5275 dst_vma
->vm_flags
& VM_WRITE
);
5276 hugetlb_count_add(pages_per_huge_page(h
), dst_mm
);
5278 /* No need to invalidate - it was non-present before */
5279 update_mmu_cache(dst_vma
, dst_addr
, dst_pte
);
5283 SetHPageMigratable(page
);
5284 if (vm_shared
|| is_continue
)
5291 if (vm_shared
|| is_continue
)
5293 out_release_nounlock
:
5294 restore_reserve_on_error(h
, dst_vma
, dst_addr
, page
);
5298 #endif /* CONFIG_USERFAULTFD */
5300 static void record_subpages_vmas(struct page
*page
, struct vm_area_struct
*vma
,
5301 int refs
, struct page
**pages
,
5302 struct vm_area_struct
**vmas
)
5306 for (nr
= 0; nr
< refs
; nr
++) {
5308 pages
[nr
] = mem_map_offset(page
, nr
);
5314 long follow_hugetlb_page(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
5315 struct page
**pages
, struct vm_area_struct
**vmas
,
5316 unsigned long *position
, unsigned long *nr_pages
,
5317 long i
, unsigned int flags
, int *locked
)
5319 unsigned long pfn_offset
;
5320 unsigned long vaddr
= *position
;
5321 unsigned long remainder
= *nr_pages
;
5322 struct hstate
*h
= hstate_vma(vma
);
5323 int err
= -EFAULT
, refs
;
5325 while (vaddr
< vma
->vm_end
&& remainder
) {
5327 spinlock_t
*ptl
= NULL
;
5332 * If we have a pending SIGKILL, don't keep faulting pages and
5333 * potentially allocating memory.
5335 if (fatal_signal_pending(current
)) {
5341 * Some archs (sparc64, sh*) have multiple pte_ts to
5342 * each hugepage. We have to make sure we get the
5343 * first, for the page indexing below to work.
5345 * Note that page table lock is not held when pte is null.
5347 pte
= huge_pte_offset(mm
, vaddr
& huge_page_mask(h
),
5350 ptl
= huge_pte_lock(h
, mm
, pte
);
5351 absent
= !pte
|| huge_pte_none(huge_ptep_get(pte
));
5354 * When coredumping, it suits get_dump_page if we just return
5355 * an error where there's an empty slot with no huge pagecache
5356 * to back it. This way, we avoid allocating a hugepage, and
5357 * the sparse dumpfile avoids allocating disk blocks, but its
5358 * huge holes still show up with zeroes where they need to be.
5360 if (absent
&& (flags
& FOLL_DUMP
) &&
5361 !hugetlbfs_pagecache_present(h
, vma
, vaddr
)) {
5369 * We need call hugetlb_fault for both hugepages under migration
5370 * (in which case hugetlb_fault waits for the migration,) and
5371 * hwpoisoned hugepages (in which case we need to prevent the
5372 * caller from accessing to them.) In order to do this, we use
5373 * here is_swap_pte instead of is_hugetlb_entry_migration and
5374 * is_hugetlb_entry_hwpoisoned. This is because it simply covers
5375 * both cases, and because we can't follow correct pages
5376 * directly from any kind of swap entries.
5378 if (absent
|| is_swap_pte(huge_ptep_get(pte
)) ||
5379 ((flags
& FOLL_WRITE
) &&
5380 !huge_pte_write(huge_ptep_get(pte
)))) {
5382 unsigned int fault_flags
= 0;
5386 if (flags
& FOLL_WRITE
)
5387 fault_flags
|= FAULT_FLAG_WRITE
;
5389 fault_flags
|= FAULT_FLAG_ALLOW_RETRY
|
5390 FAULT_FLAG_KILLABLE
;
5391 if (flags
& FOLL_NOWAIT
)
5392 fault_flags
|= FAULT_FLAG_ALLOW_RETRY
|
5393 FAULT_FLAG_RETRY_NOWAIT
;
5394 if (flags
& FOLL_TRIED
) {
5396 * Note: FAULT_FLAG_ALLOW_RETRY and
5397 * FAULT_FLAG_TRIED can co-exist
5399 fault_flags
|= FAULT_FLAG_TRIED
;
5401 ret
= hugetlb_fault(mm
, vma
, vaddr
, fault_flags
);
5402 if (ret
& VM_FAULT_ERROR
) {
5403 err
= vm_fault_to_errno(ret
, flags
);
5407 if (ret
& VM_FAULT_RETRY
) {
5409 !(fault_flags
& FAULT_FLAG_RETRY_NOWAIT
))
5413 * VM_FAULT_RETRY must not return an
5414 * error, it will return zero
5417 * No need to update "position" as the
5418 * caller will not check it after
5419 * *nr_pages is set to 0.
5426 pfn_offset
= (vaddr
& ~huge_page_mask(h
)) >> PAGE_SHIFT
;
5427 page
= pte_page(huge_ptep_get(pte
));
5430 * If subpage information not requested, update counters
5431 * and skip the same_page loop below.
5433 if (!pages
&& !vmas
&& !pfn_offset
&&
5434 (vaddr
+ huge_page_size(h
) < vma
->vm_end
) &&
5435 (remainder
>= pages_per_huge_page(h
))) {
5436 vaddr
+= huge_page_size(h
);
5437 remainder
-= pages_per_huge_page(h
);
5438 i
+= pages_per_huge_page(h
);
5443 refs
= min3(pages_per_huge_page(h
) - pfn_offset
,
5444 (vma
->vm_end
- vaddr
) >> PAGE_SHIFT
, remainder
);
5447 record_subpages_vmas(mem_map_offset(page
, pfn_offset
),
5449 likely(pages
) ? pages
+ i
: NULL
,
5450 vmas
? vmas
+ i
: NULL
);
5454 * try_grab_compound_head() should always succeed here,
5455 * because: a) we hold the ptl lock, and b) we've just
5456 * checked that the huge page is present in the page
5457 * tables. If the huge page is present, then the tail
5458 * pages must also be present. The ptl prevents the
5459 * head page and tail pages from being rearranged in
5460 * any way. So this page must be available at this
5461 * point, unless the page refcount overflowed:
5463 if (WARN_ON_ONCE(!try_grab_compound_head(pages
[i
],
5473 vaddr
+= (refs
<< PAGE_SHIFT
);
5479 *nr_pages
= remainder
;
5481 * setting position is actually required only if remainder is
5482 * not zero but it's faster not to add a "if (remainder)"
5490 unsigned long hugetlb_change_protection(struct vm_area_struct
*vma
,
5491 unsigned long address
, unsigned long end
, pgprot_t newprot
)
5493 struct mm_struct
*mm
= vma
->vm_mm
;
5494 unsigned long start
= address
;
5497 struct hstate
*h
= hstate_vma(vma
);
5498 unsigned long pages
= 0;
5499 bool shared_pmd
= false;
5500 struct mmu_notifier_range range
;
5503 * In the case of shared PMDs, the area to flush could be beyond
5504 * start/end. Set range.start/range.end to cover the maximum possible
5505 * range if PMD sharing is possible.
5507 mmu_notifier_range_init(&range
, MMU_NOTIFY_PROTECTION_VMA
,
5508 0, vma
, mm
, start
, end
);
5509 adjust_range_if_pmd_sharing_possible(vma
, &range
.start
, &range
.end
);
5511 BUG_ON(address
>= end
);
5512 flush_cache_range(vma
, range
.start
, range
.end
);
5514 mmu_notifier_invalidate_range_start(&range
);
5515 i_mmap_lock_write(vma
->vm_file
->f_mapping
);
5516 for (; address
< end
; address
+= huge_page_size(h
)) {
5518 ptep
= huge_pte_offset(mm
, address
, huge_page_size(h
));
5521 ptl
= huge_pte_lock(h
, mm
, ptep
);
5522 if (huge_pmd_unshare(mm
, vma
, &address
, ptep
)) {
5528 pte
= huge_ptep_get(ptep
);
5529 if (unlikely(is_hugetlb_entry_hwpoisoned(pte
))) {
5533 if (unlikely(is_hugetlb_entry_migration(pte
))) {
5534 swp_entry_t entry
= pte_to_swp_entry(pte
);
5536 if (is_writable_migration_entry(entry
)) {
5539 entry
= make_readable_migration_entry(
5541 newpte
= swp_entry_to_pte(entry
);
5542 set_huge_swap_pte_at(mm
, address
, ptep
,
5543 newpte
, huge_page_size(h
));
5549 if (!huge_pte_none(pte
)) {
5551 unsigned int shift
= huge_page_shift(hstate_vma(vma
));
5553 old_pte
= huge_ptep_modify_prot_start(vma
, address
, ptep
);
5554 pte
= pte_mkhuge(huge_pte_modify(old_pte
, newprot
));
5555 pte
= arch_make_huge_pte(pte
, shift
, vma
->vm_flags
);
5556 huge_ptep_modify_prot_commit(vma
, address
, ptep
, old_pte
, pte
);
5562 * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare
5563 * may have cleared our pud entry and done put_page on the page table:
5564 * once we release i_mmap_rwsem, another task can do the final put_page
5565 * and that page table be reused and filled with junk. If we actually
5566 * did unshare a page of pmds, flush the range corresponding to the pud.
5569 flush_hugetlb_tlb_range(vma
, range
.start
, range
.end
);
5571 flush_hugetlb_tlb_range(vma
, start
, end
);
5573 * No need to call mmu_notifier_invalidate_range() we are downgrading
5574 * page table protection not changing it to point to a new page.
5576 * See Documentation/vm/mmu_notifier.rst
5578 i_mmap_unlock_write(vma
->vm_file
->f_mapping
);
5579 mmu_notifier_invalidate_range_end(&range
);
5581 return pages
<< h
->order
;
5584 /* Return true if reservation was successful, false otherwise. */
5585 bool hugetlb_reserve_pages(struct inode
*inode
,
5587 struct vm_area_struct
*vma
,
5588 vm_flags_t vm_flags
)
5591 struct hstate
*h
= hstate_inode(inode
);
5592 struct hugepage_subpool
*spool
= subpool_inode(inode
);
5593 struct resv_map
*resv_map
;
5594 struct hugetlb_cgroup
*h_cg
= NULL
;
5595 long gbl_reserve
, regions_needed
= 0;
5597 /* This should never happen */
5599 VM_WARN(1, "%s called with a negative range\n", __func__
);
5604 * Only apply hugepage reservation if asked. At fault time, an
5605 * attempt will be made for VM_NORESERVE to allocate a page
5606 * without using reserves
5608 if (vm_flags
& VM_NORESERVE
)
5612 * Shared mappings base their reservation on the number of pages that
5613 * are already allocated on behalf of the file. Private mappings need
5614 * to reserve the full area even if read-only as mprotect() may be
5615 * called to make the mapping read-write. Assume !vma is a shm mapping
5617 if (!vma
|| vma
->vm_flags
& VM_MAYSHARE
) {
5619 * resv_map can not be NULL as hugetlb_reserve_pages is only
5620 * called for inodes for which resv_maps were created (see
5621 * hugetlbfs_get_inode).
5623 resv_map
= inode_resv_map(inode
);
5625 chg
= region_chg(resv_map
, from
, to
, ®ions_needed
);
5628 /* Private mapping. */
5629 resv_map
= resv_map_alloc();
5635 set_vma_resv_map(vma
, resv_map
);
5636 set_vma_resv_flags(vma
, HPAGE_RESV_OWNER
);
5642 if (hugetlb_cgroup_charge_cgroup_rsvd(hstate_index(h
),
5643 chg
* pages_per_huge_page(h
), &h_cg
) < 0)
5646 if (vma
&& !(vma
->vm_flags
& VM_MAYSHARE
) && h_cg
) {
5647 /* For private mappings, the hugetlb_cgroup uncharge info hangs
5650 resv_map_set_hugetlb_cgroup_uncharge_info(resv_map
, h_cg
, h
);
5654 * There must be enough pages in the subpool for the mapping. If
5655 * the subpool has a minimum size, there may be some global
5656 * reservations already in place (gbl_reserve).
5658 gbl_reserve
= hugepage_subpool_get_pages(spool
, chg
);
5659 if (gbl_reserve
< 0)
5660 goto out_uncharge_cgroup
;
5663 * Check enough hugepages are available for the reservation.
5664 * Hand the pages back to the subpool if there are not
5666 if (hugetlb_acct_memory(h
, gbl_reserve
) < 0)
5670 * Account for the reservations made. Shared mappings record regions
5671 * that have reservations as they are shared by multiple VMAs.
5672 * When the last VMA disappears, the region map says how much
5673 * the reservation was and the page cache tells how much of
5674 * the reservation was consumed. Private mappings are per-VMA and
5675 * only the consumed reservations are tracked. When the VMA
5676 * disappears, the original reservation is the VMA size and the
5677 * consumed reservations are stored in the map. Hence, nothing
5678 * else has to be done for private mappings here
5680 if (!vma
|| vma
->vm_flags
& VM_MAYSHARE
) {
5681 add
= region_add(resv_map
, from
, to
, regions_needed
, h
, h_cg
);
5683 if (unlikely(add
< 0)) {
5684 hugetlb_acct_memory(h
, -gbl_reserve
);
5686 } else if (unlikely(chg
> add
)) {
5688 * pages in this range were added to the reserve
5689 * map between region_chg and region_add. This
5690 * indicates a race with alloc_huge_page. Adjust
5691 * the subpool and reserve counts modified above
5692 * based on the difference.
5697 * hugetlb_cgroup_uncharge_cgroup_rsvd() will put the
5698 * reference to h_cg->css. See comment below for detail.
5700 hugetlb_cgroup_uncharge_cgroup_rsvd(
5702 (chg
- add
) * pages_per_huge_page(h
), h_cg
);
5704 rsv_adjust
= hugepage_subpool_put_pages(spool
,
5706 hugetlb_acct_memory(h
, -rsv_adjust
);
5709 * The file_regions will hold their own reference to
5710 * h_cg->css. So we should release the reference held
5711 * via hugetlb_cgroup_charge_cgroup_rsvd() when we are
5714 hugetlb_cgroup_put_rsvd_cgroup(h_cg
);
5720 /* put back original number of pages, chg */
5721 (void)hugepage_subpool_put_pages(spool
, chg
);
5722 out_uncharge_cgroup
:
5723 hugetlb_cgroup_uncharge_cgroup_rsvd(hstate_index(h
),
5724 chg
* pages_per_huge_page(h
), h_cg
);
5726 if (!vma
|| vma
->vm_flags
& VM_MAYSHARE
)
5727 /* Only call region_abort if the region_chg succeeded but the
5728 * region_add failed or didn't run.
5730 if (chg
>= 0 && add
< 0)
5731 region_abort(resv_map
, from
, to
, regions_needed
);
5732 if (vma
&& is_vma_resv_set(vma
, HPAGE_RESV_OWNER
))
5733 kref_put(&resv_map
->refs
, resv_map_release
);
5737 long hugetlb_unreserve_pages(struct inode
*inode
, long start
, long end
,
5740 struct hstate
*h
= hstate_inode(inode
);
5741 struct resv_map
*resv_map
= inode_resv_map(inode
);
5743 struct hugepage_subpool
*spool
= subpool_inode(inode
);
5747 * Since this routine can be called in the evict inode path for all
5748 * hugetlbfs inodes, resv_map could be NULL.
5751 chg
= region_del(resv_map
, start
, end
);
5753 * region_del() can fail in the rare case where a region
5754 * must be split and another region descriptor can not be
5755 * allocated. If end == LONG_MAX, it will not fail.
5761 spin_lock(&inode
->i_lock
);
5762 inode
->i_blocks
-= (blocks_per_huge_page(h
) * freed
);
5763 spin_unlock(&inode
->i_lock
);
5766 * If the subpool has a minimum size, the number of global
5767 * reservations to be released may be adjusted.
5769 * Note that !resv_map implies freed == 0. So (chg - freed)
5770 * won't go negative.
5772 gbl_reserve
= hugepage_subpool_put_pages(spool
, (chg
- freed
));
5773 hugetlb_acct_memory(h
, -gbl_reserve
);
5778 #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
5779 static unsigned long page_table_shareable(struct vm_area_struct
*svma
,
5780 struct vm_area_struct
*vma
,
5781 unsigned long addr
, pgoff_t idx
)
5783 unsigned long saddr
= ((idx
- svma
->vm_pgoff
) << PAGE_SHIFT
) +
5785 unsigned long sbase
= saddr
& PUD_MASK
;
5786 unsigned long s_end
= sbase
+ PUD_SIZE
;
5788 /* Allow segments to share if only one is marked locked */
5789 unsigned long vm_flags
= vma
->vm_flags
& VM_LOCKED_CLEAR_MASK
;
5790 unsigned long svm_flags
= svma
->vm_flags
& VM_LOCKED_CLEAR_MASK
;
5793 * match the virtual addresses, permission and the alignment of the
5796 if (pmd_index(addr
) != pmd_index(saddr
) ||
5797 vm_flags
!= svm_flags
||
5798 !range_in_vma(svma
, sbase
, s_end
))
5804 static bool vma_shareable(struct vm_area_struct
*vma
, unsigned long addr
)
5806 unsigned long base
= addr
& PUD_MASK
;
5807 unsigned long end
= base
+ PUD_SIZE
;
5810 * check on proper vm_flags and page table alignment
5812 if (vma
->vm_flags
& VM_MAYSHARE
&& range_in_vma(vma
, base
, end
))
5817 bool want_pmd_share(struct vm_area_struct
*vma
, unsigned long addr
)
5819 #ifdef CONFIG_USERFAULTFD
5820 if (uffd_disable_huge_pmd_share(vma
))
5823 return vma_shareable(vma
, addr
);
5827 * Determine if start,end range within vma could be mapped by shared pmd.
5828 * If yes, adjust start and end to cover range associated with possible
5829 * shared pmd mappings.
5831 void adjust_range_if_pmd_sharing_possible(struct vm_area_struct
*vma
,
5832 unsigned long *start
, unsigned long *end
)
5834 unsigned long v_start
= ALIGN(vma
->vm_start
, PUD_SIZE
),
5835 v_end
= ALIGN_DOWN(vma
->vm_end
, PUD_SIZE
);
5838 * vma needs to span at least one aligned PUD size, and the range
5839 * must be at least partially within in.
5841 if (!(vma
->vm_flags
& VM_MAYSHARE
) || !(v_end
> v_start
) ||
5842 (*end
<= v_start
) || (*start
>= v_end
))
5845 /* Extend the range to be PUD aligned for a worst case scenario */
5846 if (*start
> v_start
)
5847 *start
= ALIGN_DOWN(*start
, PUD_SIZE
);
5850 *end
= ALIGN(*end
, PUD_SIZE
);
5854 * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc()
5855 * and returns the corresponding pte. While this is not necessary for the
5856 * !shared pmd case because we can allocate the pmd later as well, it makes the
5857 * code much cleaner.
5859 * This routine must be called with i_mmap_rwsem held in at least read mode if
5860 * sharing is possible. For hugetlbfs, this prevents removal of any page
5861 * table entries associated with the address space. This is important as we
5862 * are setting up sharing based on existing page table entries (mappings).
5864 * NOTE: This routine is only called from huge_pte_alloc. Some callers of
5865 * huge_pte_alloc know that sharing is not possible and do not take
5866 * i_mmap_rwsem as a performance optimization. This is handled by the
5867 * if !vma_shareable check at the beginning of the routine. i_mmap_rwsem is
5868 * only required for subsequent processing.
5870 pte_t
*huge_pmd_share(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
5871 unsigned long addr
, pud_t
*pud
)
5873 struct address_space
*mapping
= vma
->vm_file
->f_mapping
;
5874 pgoff_t idx
= ((addr
- vma
->vm_start
) >> PAGE_SHIFT
) +
5876 struct vm_area_struct
*svma
;
5877 unsigned long saddr
;
5882 i_mmap_assert_locked(mapping
);
5883 vma_interval_tree_foreach(svma
, &mapping
->i_mmap
, idx
, idx
) {
5887 saddr
= page_table_shareable(svma
, vma
, addr
, idx
);
5889 spte
= huge_pte_offset(svma
->vm_mm
, saddr
,
5890 vma_mmu_pagesize(svma
));
5892 get_page(virt_to_page(spte
));
5901 ptl
= huge_pte_lock(hstate_vma(vma
), mm
, spte
);
5902 if (pud_none(*pud
)) {
5903 pud_populate(mm
, pud
,
5904 (pmd_t
*)((unsigned long)spte
& PAGE_MASK
));
5907 put_page(virt_to_page(spte
));
5911 pte
= (pte_t
*)pmd_alloc(mm
, pud
, addr
);
5916 * unmap huge page backed by shared pte.
5918 * Hugetlb pte page is ref counted at the time of mapping. If pte is shared
5919 * indicated by page_count > 1, unmap is achieved by clearing pud and
5920 * decrementing the ref count. If count == 1, the pte page is not shared.
5922 * Called with page table lock held and i_mmap_rwsem held in write mode.
5924 * returns: 1 successfully unmapped a shared pte page
5925 * 0 the underlying pte page is not shared, or it is the last user
5927 int huge_pmd_unshare(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
5928 unsigned long *addr
, pte_t
*ptep
)
5930 pgd_t
*pgd
= pgd_offset(mm
, *addr
);
5931 p4d_t
*p4d
= p4d_offset(pgd
, *addr
);
5932 pud_t
*pud
= pud_offset(p4d
, *addr
);
5934 i_mmap_assert_write_locked(vma
->vm_file
->f_mapping
);
5935 BUG_ON(page_count(virt_to_page(ptep
)) == 0);
5936 if (page_count(virt_to_page(ptep
)) == 1)
5940 put_page(virt_to_page(ptep
));
5942 *addr
= ALIGN(*addr
, HPAGE_SIZE
* PTRS_PER_PTE
) - HPAGE_SIZE
;
5946 #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
5947 pte_t
*huge_pmd_share(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
5948 unsigned long addr
, pud_t
*pud
)
5953 int huge_pmd_unshare(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
5954 unsigned long *addr
, pte_t
*ptep
)
5959 void adjust_range_if_pmd_sharing_possible(struct vm_area_struct
*vma
,
5960 unsigned long *start
, unsigned long *end
)
5964 bool want_pmd_share(struct vm_area_struct
*vma
, unsigned long addr
)
5968 #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
5970 #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
5971 pte_t
*huge_pte_alloc(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
5972 unsigned long addr
, unsigned long sz
)
5979 pgd
= pgd_offset(mm
, addr
);
5980 p4d
= p4d_alloc(mm
, pgd
, addr
);
5983 pud
= pud_alloc(mm
, p4d
, addr
);
5985 if (sz
== PUD_SIZE
) {
5988 BUG_ON(sz
!= PMD_SIZE
);
5989 if (want_pmd_share(vma
, addr
) && pud_none(*pud
))
5990 pte
= huge_pmd_share(mm
, vma
, addr
, pud
);
5992 pte
= (pte_t
*)pmd_alloc(mm
, pud
, addr
);
5995 BUG_ON(pte
&& pte_present(*pte
) && !pte_huge(*pte
));
6001 * huge_pte_offset() - Walk the page table to resolve the hugepage
6002 * entry at address @addr
6004 * Return: Pointer to page table entry (PUD or PMD) for
6005 * address @addr, or NULL if a !p*d_present() entry is encountered and the
6006 * size @sz doesn't match the hugepage size at this level of the page
6009 pte_t
*huge_pte_offset(struct mm_struct
*mm
,
6010 unsigned long addr
, unsigned long sz
)
6017 pgd
= pgd_offset(mm
, addr
);
6018 if (!pgd_present(*pgd
))
6020 p4d
= p4d_offset(pgd
, addr
);
6021 if (!p4d_present(*p4d
))
6024 pud
= pud_offset(p4d
, addr
);
6026 /* must be pud huge, non-present or none */
6027 return (pte_t
*)pud
;
6028 if (!pud_present(*pud
))
6030 /* must have a valid entry and size to go further */
6032 pmd
= pmd_offset(pud
, addr
);
6033 /* must be pmd huge, non-present or none */
6034 return (pte_t
*)pmd
;
6037 #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
6040 * These functions are overwritable if your architecture needs its own
6043 struct page
* __weak
6044 follow_huge_addr(struct mm_struct
*mm
, unsigned long address
,
6047 return ERR_PTR(-EINVAL
);
6050 struct page
* __weak
6051 follow_huge_pd(struct vm_area_struct
*vma
,
6052 unsigned long address
, hugepd_t hpd
, int flags
, int pdshift
)
6054 WARN(1, "hugepd follow called with no support for hugepage directory format\n");
6058 struct page
* __weak
6059 follow_huge_pmd(struct mm_struct
*mm
, unsigned long address
,
6060 pmd_t
*pmd
, int flags
)
6062 struct page
*page
= NULL
;
6066 /* FOLL_GET and FOLL_PIN are mutually exclusive. */
6067 if (WARN_ON_ONCE((flags
& (FOLL_PIN
| FOLL_GET
)) ==
6068 (FOLL_PIN
| FOLL_GET
)))
6072 ptl
= pmd_lockptr(mm
, pmd
);
6075 * make sure that the address range covered by this pmd is not
6076 * unmapped from other threads.
6078 if (!pmd_huge(*pmd
))
6080 pte
= huge_ptep_get((pte_t
*)pmd
);
6081 if (pte_present(pte
)) {
6082 page
= pmd_page(*pmd
) + ((address
& ~PMD_MASK
) >> PAGE_SHIFT
);
6084 * try_grab_page() should always succeed here, because: a) we
6085 * hold the pmd (ptl) lock, and b) we've just checked that the
6086 * huge pmd (head) page is present in the page tables. The ptl
6087 * prevents the head page and tail pages from being rearranged
6088 * in any way. So this page must be available at this point,
6089 * unless the page refcount overflowed:
6091 if (WARN_ON_ONCE(!try_grab_page(page
, flags
))) {
6096 if (is_hugetlb_entry_migration(pte
)) {
6098 __migration_entry_wait(mm
, (pte_t
*)pmd
, ptl
);
6102 * hwpoisoned entry is treated as no_page_table in
6103 * follow_page_mask().
6111 struct page
* __weak
6112 follow_huge_pud(struct mm_struct
*mm
, unsigned long address
,
6113 pud_t
*pud
, int flags
)
6115 if (flags
& (FOLL_GET
| FOLL_PIN
))
6118 return pte_page(*(pte_t
*)pud
) + ((address
& ~PUD_MASK
) >> PAGE_SHIFT
);
6121 struct page
* __weak
6122 follow_huge_pgd(struct mm_struct
*mm
, unsigned long address
, pgd_t
*pgd
, int flags
)
6124 if (flags
& (FOLL_GET
| FOLL_PIN
))
6127 return pte_page(*(pte_t
*)pgd
) + ((address
& ~PGDIR_MASK
) >> PAGE_SHIFT
);
6130 bool isolate_huge_page(struct page
*page
, struct list_head
*list
)
6134 spin_lock_irq(&hugetlb_lock
);
6135 if (!PageHeadHuge(page
) ||
6136 !HPageMigratable(page
) ||
6137 !get_page_unless_zero(page
)) {
6141 ClearHPageMigratable(page
);
6142 list_move_tail(&page
->lru
, list
);
6144 spin_unlock_irq(&hugetlb_lock
);
6148 int get_hwpoison_huge_page(struct page
*page
, bool *hugetlb
)
6153 spin_lock_irq(&hugetlb_lock
);
6154 if (PageHeadHuge(page
)) {
6156 if (HPageFreed(page
) || HPageMigratable(page
))
6157 ret
= get_page_unless_zero(page
);
6161 spin_unlock_irq(&hugetlb_lock
);
6165 void putback_active_hugepage(struct page
*page
)
6167 spin_lock_irq(&hugetlb_lock
);
6168 SetHPageMigratable(page
);
6169 list_move_tail(&page
->lru
, &(page_hstate(page
))->hugepage_activelist
);
6170 spin_unlock_irq(&hugetlb_lock
);
6174 void move_hugetlb_state(struct page
*oldpage
, struct page
*newpage
, int reason
)
6176 struct hstate
*h
= page_hstate(oldpage
);
6178 hugetlb_cgroup_migrate(oldpage
, newpage
);
6179 set_page_owner_migrate_reason(newpage
, reason
);
6182 * transfer temporary state of the new huge page. This is
6183 * reverse to other transitions because the newpage is going to
6184 * be final while the old one will be freed so it takes over
6185 * the temporary status.
6187 * Also note that we have to transfer the per-node surplus state
6188 * here as well otherwise the global surplus count will not match
6191 if (HPageTemporary(newpage
)) {
6192 int old_nid
= page_to_nid(oldpage
);
6193 int new_nid
= page_to_nid(newpage
);
6195 SetHPageTemporary(oldpage
);
6196 ClearHPageTemporary(newpage
);
6199 * There is no need to transfer the per-node surplus state
6200 * when we do not cross the node.
6202 if (new_nid
== old_nid
)
6204 spin_lock_irq(&hugetlb_lock
);
6205 if (h
->surplus_huge_pages_node
[old_nid
]) {
6206 h
->surplus_huge_pages_node
[old_nid
]--;
6207 h
->surplus_huge_pages_node
[new_nid
]++;
6209 spin_unlock_irq(&hugetlb_lock
);
6214 * This function will unconditionally remove all the shared pmd pgtable entries
6215 * within the specific vma for a hugetlbfs memory range.
6217 void hugetlb_unshare_all_pmds(struct vm_area_struct
*vma
)
6219 struct hstate
*h
= hstate_vma(vma
);
6220 unsigned long sz
= huge_page_size(h
);
6221 struct mm_struct
*mm
= vma
->vm_mm
;
6222 struct mmu_notifier_range range
;
6223 unsigned long address
, start
, end
;
6227 if (!(vma
->vm_flags
& VM_MAYSHARE
))
6230 start
= ALIGN(vma
->vm_start
, PUD_SIZE
);
6231 end
= ALIGN_DOWN(vma
->vm_end
, PUD_SIZE
);
6237 * No need to call adjust_range_if_pmd_sharing_possible(), because
6238 * we have already done the PUD_SIZE alignment.
6240 mmu_notifier_range_init(&range
, MMU_NOTIFY_CLEAR
, 0, vma
, mm
,
6242 mmu_notifier_invalidate_range_start(&range
);
6243 i_mmap_lock_write(vma
->vm_file
->f_mapping
);
6244 for (address
= start
; address
< end
; address
+= PUD_SIZE
) {
6245 unsigned long tmp
= address
;
6247 ptep
= huge_pte_offset(mm
, address
, sz
);
6250 ptl
= huge_pte_lock(h
, mm
, ptep
);
6251 /* We don't want 'address' to be changed */
6252 huge_pmd_unshare(mm
, vma
, &tmp
, ptep
);
6255 flush_hugetlb_tlb_range(vma
, start
, end
);
6256 i_mmap_unlock_write(vma
->vm_file
->f_mapping
);
6258 * No need to call mmu_notifier_invalidate_range(), see
6259 * Documentation/vm/mmu_notifier.rst.
6261 mmu_notifier_invalidate_range_end(&range
);
6265 static bool cma_reserve_called __initdata
;
6267 static int __init
cmdline_parse_hugetlb_cma(char *p
)
6269 hugetlb_cma_size
= memparse(p
, &p
);
6273 early_param("hugetlb_cma", cmdline_parse_hugetlb_cma
);
6275 void __init
hugetlb_cma_reserve(int order
)
6277 unsigned long size
, reserved
, per_node
;
6280 cma_reserve_called
= true;
6282 if (!hugetlb_cma_size
)
6285 if (hugetlb_cma_size
< (PAGE_SIZE
<< order
)) {
6286 pr_warn("hugetlb_cma: cma area should be at least %lu MiB\n",
6287 (PAGE_SIZE
<< order
) / SZ_1M
);
6292 * If 3 GB area is requested on a machine with 4 numa nodes,
6293 * let's allocate 1 GB on first three nodes and ignore the last one.
6295 per_node
= DIV_ROUND_UP(hugetlb_cma_size
, nr_online_nodes
);
6296 pr_info("hugetlb_cma: reserve %lu MiB, up to %lu MiB per node\n",
6297 hugetlb_cma_size
/ SZ_1M
, per_node
/ SZ_1M
);
6300 for_each_node_state(nid
, N_ONLINE
) {
6302 char name
[CMA_MAX_NAME
];
6304 size
= min(per_node
, hugetlb_cma_size
- reserved
);
6305 size
= round_up(size
, PAGE_SIZE
<< order
);
6307 snprintf(name
, sizeof(name
), "hugetlb%d", nid
);
6308 res
= cma_declare_contiguous_nid(0, size
, 0, PAGE_SIZE
<< order
,
6310 &hugetlb_cma
[nid
], nid
);
6312 pr_warn("hugetlb_cma: reservation failed: err %d, node %d",
6318 pr_info("hugetlb_cma: reserved %lu MiB on node %d\n",
6321 if (reserved
>= hugetlb_cma_size
)
6326 void __init
hugetlb_cma_check(void)
6328 if (!hugetlb_cma_size
|| cma_reserve_called
)
6331 pr_warn("hugetlb_cma: the option isn't supported by current arch\n");
6334 #endif /* CONFIG_CMA */