[PATCH -next 5/7] mm: memory: convert wp_page_copy() to use folios

From: Kefeng Wang
Date: Thu Jan 12 2023 - 03:19:29 EST


The old_page/new_page are converted to old_folio/new_folio in
wp_page_copy(), then replaced related page functions to folio
functions.

Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
mm/memory.c | 47 +++++++++++++++++++++++++----------------------
1 file changed, 25 insertions(+), 22 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index b66c425b4d7c..746f485366e8 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3044,7 +3044,9 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
struct vm_area_struct *vma = vmf->vma;
struct mm_struct *mm = vma->vm_mm;
struct page *old_page = vmf->page;
+ struct folio *old_folio = page_folio(old_page);
struct page *new_page = NULL;
+ struct folio *new_folio = NULL;
pte_t entry;
int page_copied = 0;
struct mmu_notifier_range range;
@@ -3060,12 +3062,13 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
vmf->address);
if (!new_page)
goto oom;
+ new_folio = page_folio(new_page);
} else {
- new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma,
- vmf->address);
- if (!new_page)
+ new_folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, vma,
+ vmf->address, false);
+ if (!new_folio)
goto oom;
-
+ new_page = &new_folio->page;
ret = __wp_page_copy_user(new_page, old_page, vmf);
if (ret) {
/*
@@ -3075,9 +3078,9 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
* from the second attempt.
* The -EHWPOISON case will not be retried.
*/
- put_page(new_page);
- if (old_page)
- put_page(old_page);
+ folio_put(new_folio);
+ if (old_folio)
+ folio_put(old_folio);

delayacct_wpcopy_end();
return ret == -EHWPOISON ? VM_FAULT_HWPOISON : 0;
@@ -3085,11 +3088,11 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
kmsan_copy_page_meta(new_page, old_page);
}

- if (mem_cgroup_charge(page_folio(new_page), mm, GFP_KERNEL))
+ if (mem_cgroup_charge(new_folio, mm, GFP_KERNEL))
goto oom_free_new;
- cgroup_throttle_swaprate(new_page, GFP_KERNEL);
+ folio_throttle_swaprate(new_folio, GFP_KERNEL);

- __SetPageUptodate(new_page);
+ __folio_mark_uptodate(new_folio);

mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, mm,
vmf->address & PAGE_MASK,
@@ -3101,8 +3104,8 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
*/
vmf->pte = pte_offset_map_lock(mm, vmf->pmd, vmf->address, &vmf->ptl);
if (likely(pte_same(*vmf->pte, vmf->orig_pte))) {
- if (old_page) {
- if (!PageAnon(old_page)) {
+ if (old_folio) {
+ if (!folio_test_anon(old_folio)) {
dec_mm_counter(mm, mm_counter_file(old_page));
inc_mm_counter(mm, MM_ANONPAGES);
}
@@ -3130,7 +3133,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
*/
ptep_clear_flush_notify(vma, vmf->address, vmf->pte);
page_add_new_anon_rmap(new_page, vma, vmf->address);
- lru_cache_add_inactive_or_unevictable(new_page, vma);
+ folio_add_lru_vma(new_folio, vma);
/*
* We call the notify macro here because, when using secondary
* mmu page tables (such as kvm shadow page tables), we want the
@@ -3139,7 +3142,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
BUG_ON(unshare && pte_write(entry));
set_pte_at_notify(mm, vmf->address, vmf->pte, entry);
update_mmu_cache(vma, vmf->address, vmf->pte);
- if (old_page) {
+ if (old_folio) {
/*
* Only after switching the pte to the new page may
* we remove the mapcount here. Otherwise another
@@ -3166,14 +3169,14 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
}

/* Free the old page.. */
- new_page = old_page;
+ new_folio = old_folio;
page_copied = 1;
} else {
update_mmu_tlb(vma, vmf->address, vmf->pte);
}

- if (new_page)
- put_page(new_page);
+ if (new_folio)
+ folio_put(new_folio);

pte_unmap_unlock(vmf->pte, vmf->ptl);
/*
@@ -3181,19 +3184,19 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
* the above ptep_clear_flush_notify() did already call it.
*/
mmu_notifier_invalidate_range_only_end(&range);
- if (old_page) {
+ if (old_folio) {
if (page_copied)
free_swap_cache(old_page);
- put_page(old_page);
+ folio_put(old_folio);
}

delayacct_wpcopy_end();
return 0;
oom_free_new:
- put_page(new_page);
+ folio_put(new_folio);
oom:
- if (old_page)
- put_page(old_page);
+ if (old_folio)
+ folio_put(old_folio);

delayacct_wpcopy_end();
return VM_FAULT_OOM;
--
2.35.3