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-rw-r--r--mm/hugetlb.c78
1 files changed, 51 insertions, 27 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 224cdd953a79..310656b4ede6 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1081,11 +1081,10 @@ static bool pfn_range_valid_gigantic(struct zone *z,
struct page *page;
for (i = start_pfn; i < end_pfn; i++) {
- if (!pfn_valid(i))
+ page = pfn_to_online_page(i);
+ if (!page)
return false;
- page = pfn_to_page(i);
-
if (page_zone(page) != z)
return false;
@@ -1271,12 +1270,23 @@ void free_huge_page(struct page *page)
ClearPagePrivate(page);
/*
- * A return code of zero implies that the subpool will be under its
- * minimum size if the reservation is not restored after page is free.
- * Therefore, force restore_reserve operation.
+ * If PagePrivate() was set on page, page allocation consumed a
+ * reservation. If the page was associated with a subpool, there
+ * would have been a page reserved in the subpool before allocation
+ * via hugepage_subpool_get_pages(). Since we are 'restoring' the
+ * reservtion, do not call hugepage_subpool_put_pages() as this will
+ * remove the reserved page from the subpool.
*/
- if (hugepage_subpool_put_pages(spool, 1) == 0)
- restore_reserve = true;
+ if (!restore_reserve) {
+ /*
+ * A return code of zero implies that the subpool will be
+ * under its minimum size if the reservation is not restored
+ * after page is free. Therefore, force restore_reserve
+ * operation.
+ */
+ if (hugepage_subpool_put_pages(spool, 1) == 0)
+ restore_reserve = true;
+ }
spin_lock(&hugetlb_lock);
clear_page_huge_active(page);
@@ -3577,7 +3587,6 @@ retry_avoidcopy:
copy_user_huge_page(new_page, old_page, address, vma,
pages_per_huge_page(h));
__SetPageUptodate(new_page);
- set_page_huge_active(new_page);
mmun_start = address & huge_page_mask(h);
mmun_end = mmun_start + huge_page_size(h);
@@ -3600,6 +3609,7 @@ retry_avoidcopy:
make_huge_pte(vma, new_page, 1));
page_remove_rmap(old_page, true);
hugepage_add_new_anon_rmap(new_page, vma, address);
+ set_page_huge_active(new_page);
/* Make the old page be freed below */
new_page = old_page;
}
@@ -3682,6 +3692,7 @@ static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
struct page *page;
pte_t new_pte;
spinlock_t *ptl;
+ bool new_page = false;
/*
* Currently, we are forced to kill the process in the event the
@@ -3728,8 +3739,8 @@ retry:
* handling userfault. Reacquire after handling
* fault to make calling code simpler.
*/
- hash = hugetlb_fault_mutex_hash(h, mm, vma, mapping,
- idx, address);
+ hash = hugetlb_fault_mutex_hash(h, mapping, idx,
+ address);
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
ret = handle_userfault(&vmf, VM_UFFD_MISSING);
mutex_lock(&hugetlb_fault_mutex_table[hash]);
@@ -3747,7 +3758,7 @@ retry:
}
clear_huge_page(page, address, pages_per_huge_page(h));
__SetPageUptodate(page);
- set_page_huge_active(page);
+ new_page = true;
if (vma->vm_flags & VM_MAYSHARE) {
int err = huge_add_to_page_cache(page, mapping, idx);
@@ -3818,6 +3829,15 @@ retry:
}
spin_unlock(ptl);
+
+ /*
+ * Only make newly allocated pages active. Existing pages found
+ * in the pagecache could be !page_huge_active() if they have been
+ * isolated for migration.
+ */
+ if (new_page)
+ set_page_huge_active(page);
+
unlock_page(page);
out:
return ret;
@@ -3832,21 +3852,14 @@ backout_unlocked:
}
#ifdef CONFIG_SMP
-u32 hugetlb_fault_mutex_hash(struct hstate *h, struct mm_struct *mm,
- struct vm_area_struct *vma,
- struct address_space *mapping,
+u32 hugetlb_fault_mutex_hash(struct hstate *h, struct address_space *mapping,
pgoff_t idx, unsigned long address)
{
unsigned long key[2];
u32 hash;
- if (vma->vm_flags & VM_SHARED) {
- key[0] = (unsigned long) mapping;
- key[1] = idx;
- } else {
- key[0] = (unsigned long) mm;
- key[1] = address >> huge_page_shift(h);
- }
+ key[0] = (unsigned long) mapping;
+ key[1] = idx;
hash = jhash2((u32 *)&key, sizeof(key)/sizeof(u32), 0);
@@ -3857,9 +3870,7 @@ u32 hugetlb_fault_mutex_hash(struct hstate *h, struct mm_struct *mm,
* For uniprocesor systems we always use a single mutex, so just
* return 0 and avoid the hashing overhead.
*/
-u32 hugetlb_fault_mutex_hash(struct hstate *h, struct mm_struct *mm,
- struct vm_area_struct *vma,
- struct address_space *mapping,
+u32 hugetlb_fault_mutex_hash(struct hstate *h, struct address_space *mapping,
pgoff_t idx, unsigned long address)
{
return 0;
@@ -3905,7 +3916,7 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
* get spurious allocation failures if two CPUs race to instantiate
* the same page in the page cache.
*/
- hash = hugetlb_fault_mutex_hash(h, mm, vma, mapping, idx, address);
+ hash = hugetlb_fault_mutex_hash(h, mapping, idx, address);
mutex_lock(&hugetlb_fault_mutex_table[hash]);
entry = huge_ptep_get(ptep);
@@ -4053,7 +4064,6 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
* the set_pte_at() write.
*/
__SetPageUptodate(page);
- set_page_huge_active(page);
mapping = dst_vma->vm_file->f_mapping;
idx = vma_hugecache_offset(h, dst_vma, dst_addr);
@@ -4121,6 +4131,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
update_mmu_cache(dst_vma, dst_addr, dst_pte);
spin_unlock(ptl);
+ set_page_huge_active(page);
if (vm_shared)
unlock_page(page);
ret = 0;
@@ -4245,6 +4256,19 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT;
page = pte_page(huge_ptep_get(pte));
+
+ /*
+ * Instead of doing 'try_get_page()' below in the same_page
+ * loop, just check the count once here.
+ */
+ if (unlikely(page_count(page) <= 0)) {
+ if (pages) {
+ spin_unlock(ptl);
+ remainder = 0;
+ err = -ENOMEM;
+ break;
+ }
+ }
same_page:
if (pages) {
pages[i] = mem_map_offset(page, pfn_offset);