[PATCH -next 2/7] mm: mprotect: use a folio in change_pte_range()

From: Kefeng Wang
Date: Tue Oct 10 2023 - 02:47:18 EST


Use a folio in change_pte_range() to save three compound_head() calls.

Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
mm/mprotect.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/mm/mprotect.c b/mm/mprotect.c
index b94fbb45d5c7..459daa987131 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -114,7 +114,7 @@ static long change_pte_range(struct mmu_gather *tlb,
* pages. See similar comment in change_huge_pmd.
*/
if (prot_numa) {
- struct page *page;
+ struct folio *folio;
int nid;
bool toptier;

@@ -122,13 +122,14 @@ static long change_pte_range(struct mmu_gather *tlb,
if (pte_protnone(oldpte))
continue;

- page = vm_normal_page(vma, addr, oldpte);
- if (!page || is_zone_device_page(page) || PageKsm(page))
+ folio = vm_normal_folio(vma, addr, oldpte);
+ if (!folio || folio_is_zone_device(folio) ||
+ folio_test_ksm(folio))
continue;

/* Also skip shared copy-on-write pages */
if (is_cow_mapping(vma->vm_flags) &&
- page_count(page) != 1)
+ folio_ref_count(folio) != 1)
continue;

/*
@@ -136,14 +137,15 @@ static long change_pte_range(struct mmu_gather *tlb,
* it cannot move them all from MIGRATE_ASYNC
* context.
*/
- if (page_is_file_lru(page) && PageDirty(page))
+ if (folio_is_file_lru(folio) &&
+ folio_test_dirty(folio))
continue;

/*
* Don't mess with PTEs if page is already on the node
* a single-threaded process is running on.
*/
- nid = page_to_nid(page);
+ nid = folio_nid(folio);
if (target_node == nid)
continue;
toptier = node_is_toptier(nid);
@@ -157,7 +159,7 @@ static long change_pte_range(struct mmu_gather *tlb,
continue;
if (sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING &&
!toptier)
- xchg_page_access_time(page,
+ xchg_page_access_time(&folio->page,
jiffies_to_msecs(jiffies));
}

--
2.27.0