[PATCH v1 2/2] fs/proc/task_mmu: convert smaps_hugetlb_range() to work on folios

From: David Hildenbrand
Date: Wed Apr 17 2024 - 05:23:58 EST


Let's get rid of another page_mapcount() check and simply use
folio_likely_mapped_shared(), which is precise for hugetlb folios.

While at it, use huge_ptep_get() + pte_page() instead of ptep_get() +
vm_normal_page(), just like we do in pagemap_hugetlb_range().

No functional change intended.

Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
fs/proc/task_mmu.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index cd6e45e0cde8e..f4259b7edfded 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -730,19 +730,20 @@ static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
{
struct mem_size_stats *mss = walk->private;
struct vm_area_struct *vma = walk->vma;
- struct page *page = NULL;
- pte_t ptent = ptep_get(pte);
+ pte_t ptent = huge_ptep_get(pte);
+ struct folio *folio = NULL;

if (pte_present(ptent)) {
- page = vm_normal_page(vma, addr, ptent);
+ folio = page_folio(pte_page(ptent));
} else if (is_swap_pte(ptent)) {
swp_entry_t swpent = pte_to_swp_entry(ptent);

if (is_pfn_swap_entry(swpent))
- page = pfn_swap_entry_to_page(swpent);
+ folio = pfn_swap_entry_folio(swpent);
}
- if (page) {
- if (page_mapcount(page) >= 2 || hugetlb_pmd_shared(pte))
+ if (folio) {
+ if (folio_likely_mapped_shared(folio) ||
+ hugetlb_pmd_shared(pte))
mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
else
mss->private_hugetlb += huge_page_size(hstate_vma(vma));
--
2.44.0