[PATCH 0/5] mm: remove page idle and young wrapper

[PATCH 0/5] mm: remove page idle and young wrapper

[Kefeng Wang]

Convert to use folio idle and young functions instead of page ones,
then remove all page idle and young wrapper.

Kefeng Wang (5):
  mm: huge_memory: use more folio api in __split_huge_page_tail()
  mm: task_mmu: use a folio in smaps_account()
  mm: task_mmu: use a folio in clear_refs_pte_range()
  fs/proc/page: use a folio in stable_page_flags()
  page_idle: kill page idle and young wrapper

 fs/proc/page.c            | 22 +++++++++++-----------
 fs/proc/task_mmu.c        | 28 +++++++++++++++-------------
 include/linux/page_idle.h | 25 -------------------------
 mm/huge_memory.c          | 12 ++++++------
 4 files changed, 32 insertions(+), 55 deletions(-)

-- 
2.27.0

[PATCH 1/5] mm: huge_memory: use more folio api in __split_huge_page_tail()

[Kefeng Wang]

Use more folio APIs to save six compound_head() calls in
__split_huge_page_tail().

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 mm/huge_memory.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index f31f02472396..34001ef9d029 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2507,13 +2507,13 @@ static void __split_huge_page_tail(struct folio *folio, int tail,
 	clear_compound_head(page_tail);
 
 	/* Finally unfreeze refcount. Additional reference from page cache. */
-	page_ref_unfreeze(page_tail, 1 + (!PageAnon(head) ||
-					  PageSwapCache(head)));
+	page_ref_unfreeze(page_tail, 1 + (!folio_test_anon(folio) ||
+					  folio_test_swapcache(folio)));
 
-	if (page_is_young(head))
-		set_page_young(page_tail);
-	if (page_is_idle(head))
-		set_page_idle(page_tail);
+	if (folio_test_young(folio))
+		folio_set_young(new_folio);
+	if (folio_test_idle(folio))
+		folio_set_idle(new_folio);
 
 	folio_xchg_last_cpupid(new_folio, folio_last_cpupid(folio));
 
-- 
2.27.0

[PATCH 2/5] mm: task_mmu: use a folio in smaps_account()

[Kefeng Wang]

Replace seven implicit calls to compound_head() with one page_folio().

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 fs/proc/task_mmu.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index ef2eb12906da..5ec06fee1f14 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -445,23 +445,25 @@ static void smaps_account(struct mem_size_stats *mss, struct page *page,
 {
 	int i, nr = compound ? compound_nr(page) : 1;
 	unsigned long size = nr * PAGE_SIZE;
+	struct folio *folio = page_folio(page);
 
 	/*
 	 * First accumulate quantities that depend only on |size| and the type
 	 * of the compound page.
 	 */
-	if (PageAnon(page)) {
+	if (folio_test_anon(folio)) {
 		mss->anonymous += size;
-		if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
+		if (!folio_test_swapbacked(folio) && !dirty &&
+		    !folio_test_dirty(folio))
 			mss->lazyfree += size;
 	}
 
-	if (PageKsm(page))
+	if (folio_test_ksm(folio))
 		mss->ksm += size;
 
 	mss->resident += size;
 	/* Accumulate the size in pages that have been accessed. */
-	if (young || page_is_young(page) || PageReferenced(page))
+	if (young || folio_test_young(folio) || folio_test_referenced(folio))
 		mss->referenced += size;
 
 	/*
@@ -479,7 +481,7 @@ static void smaps_account(struct mem_size_stats *mss, struct page *page,
 	 * especially for migration entries.  Treat regular migration entries
 	 * as mapcount == 1.
 	 */
-	if ((page_count(page) == 1) || migration) {
+	if ((folio_ref_count(folio) == 1) || migration) {
 		smaps_page_accumulate(mss, page, size, size << PSS_SHIFT, dirty,
 			locked, true);
 		return;
-- 
2.27.0

[PATCH 3/5] mm: task_mmu: use a folio in clear_refs_pte_range()

[Kefeng Wang]

Use a folio to save two compound_head() calls in clear_refs_pte_range().

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 fs/proc/task_mmu.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 5ec06fee1f14..869f6bb89230 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1161,7 +1161,7 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
 	struct vm_area_struct *vma = walk->vma;
 	pte_t *pte, ptent;
 	spinlock_t *ptl;
-	struct page *page;
+	struct folio *folio;
 
 	ptl = pmd_trans_huge_lock(pmd, vma);
 	if (ptl) {
@@ -1173,12 +1173,12 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
 		if (!pmd_present(*pmd))
 			goto out;
 
-		page = pmd_page(*pmd);
+		folio = page_folio(pmd_page(*pmd));
 
 		/* Clear accessed and referenced bits. */
 		pmdp_test_and_clear_young(vma, addr, pmd);
-		test_and_clear_page_young(page);
-		ClearPageReferenced(page);
+		folio_test_clear_young(folio);
+		folio_clear_referenced(folio);
 out:
 		spin_unlock(ptl);
 		return 0;
@@ -1200,14 +1200,14 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
 		if (!pte_present(ptent))
 			continue;
 
-		page = vm_normal_page(vma, addr, ptent);
-		if (!page)
+		folio = vm_normal_folio(vma, addr, ptent);
+		if (!folio)
 			continue;
 
 		/* Clear accessed and referenced bits. */
 		ptep_test_and_clear_young(vma, addr, pte);
-		test_and_clear_page_young(page);
-		ClearPageReferenced(page);
+		folio_test_clear_young(folio);
+		folio_clear_referenced(folio);
 	}
 	pte_unmap_unlock(pte - 1, ptl);
 	cond_resched();
-- 
2.27.0

[PATCH 4/5] fs/proc/page: use a folio in stable_page_flags()

[Kefeng Wang]

Replace ten compound_head() calls with one page_folio().

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 fs/proc/page.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/fs/proc/page.c b/fs/proc/page.c
index 195b077c0fac..94ab0ba13b16 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -109,6 +109,7 @@ static inline u64 kpf_copy_bit(u64 kflags, int ubit, int kbit)
 
 u64 stable_page_flags(struct page *page)
 {
+	struct folio *folio;
 	u64 k;
 	u64 u;
 
@@ -119,6 +120,7 @@ u64 stable_page_flags(struct page *page)
 	if (!page)
 		return 1 << KPF_NOPAGE;
 
+	folio = page_folio(page);
 	k = page->flags;
 	u = 0;
 
@@ -128,11 +130,11 @@ u64 stable_page_flags(struct page *page)
 	 * Note that page->_mapcount is overloaded in SLAB, so the
 	 * simple test in page_mapped() is not enough.
 	 */
-	if (!PageSlab(page) && page_mapped(page))
+	if (!folio_test_slab(folio) && folio_mapped(folio))
 		u |= 1 << KPF_MMAP;
-	if (PageAnon(page))
+	if (folio_test_anon(folio))
 		u |= 1 << KPF_ANON;
-	if (PageKsm(page))
+	if (folio_test_ksm(folio))
 		u |= 1 << KPF_KSM;
 
 	/*
@@ -152,11 +154,9 @@ u64 stable_page_flags(struct page *page)
 	 * to make sure a given page is a thp, not a non-huge compound page.
 	 */
 	else if (PageTransCompound(page)) {
-		struct page *head = compound_head(page);
-
-		if (PageLRU(head) || PageAnon(head))
+		if (folio_test_lru(folio) || folio_test_anon(folio))
 			u |= 1 << KPF_THP;
-		else if (is_huge_zero_page(head)) {
+		else if (is_huge_zero_page(&folio->page)) {
 			u |= 1 << KPF_ZERO_PAGE;
 			u |= 1 << KPF_THP;
 		}
@@ -170,7 +170,7 @@ u64 stable_page_flags(struct page *page)
 	 */
 	if (PageBuddy(page))
 		u |= 1 << KPF_BUDDY;
-	else if (page_count(page) == 0 && is_free_buddy_page(page))
+	else if (folio_ref_count(folio) == 0 && is_free_buddy_page(page))
 		u |= 1 << KPF_BUDDY;
 
 	if (PageOffline(page))
@@ -178,13 +178,13 @@ u64 stable_page_flags(struct page *page)
 	if (PageTable(page))
 		u |= 1 << KPF_PGTABLE;
 
-	if (page_is_idle(page))
+	if (folio_test_idle(folio))
 		u |= 1 << KPF_IDLE;
 
 	u |= kpf_copy_bit(k, KPF_LOCKED,	PG_locked);
 
 	u |= kpf_copy_bit(k, KPF_SLAB,		PG_slab);
-	if (PageTail(page) && PageSlab(page))
+	if (PageTail(page) && folio_test_slab(folio))
 		u |= 1 << KPF_SLAB;
 
 	u |= kpf_copy_bit(k, KPF_ERROR,		PG_error);
@@ -197,7 +197,7 @@ u64 stable_page_flags(struct page *page)
 	u |= kpf_copy_bit(k, KPF_ACTIVE,	PG_active);
 	u |= kpf_copy_bit(k, KPF_RECLAIM,	PG_reclaim);
 
-	if (PageSwapCache(page))
+	if (folio_test_swapcache(folio))
 		u |= 1 << KPF_SWAPCACHE;
 	u |= kpf_copy_bit(k, KPF_SWAPBACKED,	PG_swapbacked);
 
-- 
2.27.0

[PATCH 5/5] page_idle: kill page idle and young wrapper

[Kefeng Wang]

Since all the calls of page idle and young functions are gone,
let's remove all the wrapper.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 include/linux/page_idle.h | 25 -------------------------
 1 file changed, 25 deletions(-)

diff --git a/include/linux/page_idle.h b/include/linux/page_idle.h
index d8f344840643..1168d5f58ff2 100644
--- a/include/linux/page_idle.h
+++ b/include/linux/page_idle.h
@@ -119,29 +119,4 @@ static inline void folio_clear_idle(struct folio *folio)
 }
 
 #endif /* CONFIG_PAGE_IDLE_FLAG */
-
-static inline bool page_is_young(struct page *page)
-{
-	return folio_test_young(page_folio(page));
-}
-
-static inline void set_page_young(struct page *page)
-{
-	folio_set_young(page_folio(page));
-}
-
-static inline bool test_and_clear_page_young(struct page *page)
-{
-	return folio_test_clear_young(page_folio(page));
-}
-
-static inline bool page_is_idle(struct page *page)
-{
-	return folio_test_idle(page_folio(page));
-}
-
-static inline void set_page_idle(struct page *page)
-{
-	folio_set_idle(page_folio(page));
-}
 #endif /* _LINUX_MM_PAGE_IDLE_H */
-- 
2.27.0

Re: [PATCH 4/5] fs/proc/page: use a folio in stable_page_flags()

[Matthew Wilcox]

On Fri, Nov 03, 2023 at 03:29:05PM +0800, Kefeng Wang wrote:
> Replace ten compound_head() calls with one page_folio().

This is going to conflict with Gregory Price's work:

https://lore.kernel.org/linux-mm/ZUCD1dsbrFjdZgVv@memverge.com/

Perhaps the two of you can collaborate on a patch series?

>  	u |= kpf_copy_bit(k, KPF_SLAB,		PG_slab);
> -	if (PageTail(page) && PageSlab(page))
> +	if (PageTail(page) && folio_test_slab(folio))
>  		u |= 1 << KPF_SLAB;

This doesn't make sense ...

Re: [PATCH 4/5] fs/proc/page: use a folio in stable_page_flags()

[Kefeng Wang]

On 2023/11/3 20:28, Matthew Wilcox wrote:
> On Fri, Nov 03, 2023 at 03:29:05PM +0800, Kefeng Wang wrote:
>> Replace ten compound_head() calls with one page_folio().
> 
> This is going to conflict with Gregory Price's work:
> 
> https://lore.kernel.org/linux-mm/ZUCD1dsbrFjdZgVv@memverge.com/
> 
> Perhaps the two of you can collaborate on a patch series?

Will check this patch.

> 
>>   	u |= kpf_copy_bit(k, KPF_SLAB,		PG_slab);
>> -	if (PageTail(page) && PageSlab(page))
>> +	if (PageTail(page) && folio_test_slab(folio))
>>   		u |= 1 << KPF_SLAB;
> 
> This doesn't make sense ...
> 

Yes, after commit dcb351cd095a ("page-flags: define behavior SL*B-
related flags on compound pages"), the slab could not be a tail,
I will drop this line.