Refactor hugetlbfs_pagecache_present() to avoid getting and dropping
a refcount on a page. Use RCU and page_cache_next_miss() instead.
Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
---
mm/hugetlb.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 849206e94742..e506a46b7871 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5651,17 +5651,15 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
static bool hugetlbfs_pagecache_present(struct hstate *h,
struct vm_area_struct *vma, unsigned long address)
{
- struct address_space *mapping;
- pgoff_t idx;
- struct page *page;
+ struct address_space *mapping = vma->vm_file->f_mapping;
+ pgoff_t idx = vma_hugecache_offset(h, vma, address);
+ bool present;
- mapping = vma->vm_file->f_mapping;
- idx = vma_hugecache_offset(h, vma, address);
+ rcu_read_lock();
+ present = page_cache_next_miss(mapping, idx, 1) != idx;
+ rcu_read_unlock();
- page = find_get_page(mapping, idx);
- if (page)
- put_page(page);
- return page != NULL;
+ return present;
}
int hugetlb_add_to_page_cache(struct page *page, struct address_space *mapping,
--
2.39.1
