[PATCH v2 0/7] mm: remove cgroup_throttle_swaprate() completely

[PATCH v2 0/7] mm: remove cgroup_throttle_swaprate() completely

[Kefeng Wang]

Convert all the caller functions of cgroup_throttle_swaprate() to use
folios, and use folio_throttle_swaprate(),  which allows us to remove
cgroup_throttle_swaprate() completely.

v2:
- address comments from Matthew Wilcox, eg, 
  1) folio conversion inside  __do_huge_pmd_anonymous_page() function,
  2) rename __cgroup_throttle_swaprate() to __folio_throttle_swaprate()
  3) rename gfp_mask to gfp

Kefeng Wang (7):
  mm: huge_memory: convert __do_huge_pmd_anonymous_page() to use a folio
  mm: memory: use folio_throttle_swaprate() in do_swap_page()
  mm: memory: use folio_throttle_swaprate() in page_copy_prealloc()
  mm: memory: use folio_throttle_swaprate() in wp_page_copy()
  mm: memory: use folio_throttle_swaprate() in do_anonymous_page()
  mm: memory: use folio_throttle_swaprate() in do_cow_fault()
  mm: swap: remove unneeded cgroup_throttle_swaprate()

 include/linux/swap.h | 12 ++++--------
 mm/huge_memory.c     | 21 +++++++++++----------
 mm/memory.c          | 10 +++++-----
 mm/swapfile.c        |  6 +++---
 4 files changed, 23 insertions(+), 26 deletions(-)

-- 
2.35.3

[PATCH v2 1/7] mm: huge_memory: convert __do_huge_pmd_anonymous_page() to use a folio

[Kefeng Wang]

Convert from page to folio within __do_huge_pmd_anonymous_page(),
as we need the precise page which is to be stored at this PTE in
the folio, the function still keep a page as the parameter.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 mm/huge_memory.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 4fc43859e59a..39c19c5345ae 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -656,19 +656,20 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf,
 			struct page *page, gfp_t gfp)
 {
 	struct vm_area_struct *vma = vmf->vma;
+	struct folio *folio = page_folio(page);
 	pgtable_t pgtable;
 	unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
 	vm_fault_t ret = 0;
 
-	VM_BUG_ON_PAGE(!PageCompound(page), page);
+	VM_BUG_ON_FOLIO(!folio_test_large(folio), folio);
 
-	if (mem_cgroup_charge(page_folio(page), vma->vm_mm, gfp)) {
-		put_page(page);
+	if (mem_cgroup_charge(folio, vma->vm_mm, gfp)) {
+		folio_put(folio);
 		count_vm_event(THP_FAULT_FALLBACK);
 		count_vm_event(THP_FAULT_FALLBACK_CHARGE);
 		return VM_FAULT_FALLBACK;
 	}
-	cgroup_throttle_swaprate(page, gfp);
+	folio_throttle_swaprate(folio, gfp);
 
 	pgtable = pte_alloc_one(vma->vm_mm);
 	if (unlikely(!pgtable)) {
@@ -678,11 +679,11 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf,
 
 	clear_huge_page(page, vmf->address, HPAGE_PMD_NR);
 	/*
-	 * The memory barrier inside __SetPageUptodate makes sure that
+	 * The memory barrier inside __folio_mark_uptodate makes sure that
 	 * clear_huge_page writes become visible before the set_pmd_at()
 	 * write.
 	 */
-	__SetPageUptodate(page);
+	__folio_mark_uptodate(folio);
 
 	vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd);
 	if (unlikely(!pmd_none(*vmf->pmd))) {
@@ -697,7 +698,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf,
 		/* Deliver the page fault to userland */
 		if (userfaultfd_missing(vma)) {
 			spin_unlock(vmf->ptl);
-			put_page(page);
+			folio_put(folio);
 			pte_free(vma->vm_mm, pgtable);
 			ret = handle_userfault(vmf, VM_UFFD_MISSING);
 			VM_BUG_ON(ret & VM_FAULT_FALLBACK);
@@ -706,8 +707,8 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf,
 
 		entry = mk_huge_pmd(page, vma->vm_page_prot);
 		entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
-		page_add_new_anon_rmap(page, vma, haddr);
-		lru_cache_add_inactive_or_unevictable(page, vma);
+		folio_add_new_anon_rmap(folio, vma, haddr);
+		folio_add_lru_vma(folio, vma);
 		pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable);
 		set_pmd_at(vma->vm_mm, haddr, vmf->pmd, entry);
 		update_mmu_cache_pmd(vma, vmf->address, vmf->pmd);
@@ -724,7 +725,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf,
 release:
 	if (pgtable)
 		pte_free(vma->vm_mm, pgtable);
-	put_page(page);
+	folio_put(folio);
 	return ret;
 
 }
-- 
2.35.3

[PATCH v2 2/7] mm: memory: use folio_throttle_swaprate() in do_swap_page()

[Kefeng Wang]

Directly use folio_throttle_swaprate() instead of
cgroup_throttle_swaprate().

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 mm/memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memory.c b/mm/memory.c
index 255b2f4fdd4a..948fdcd4d8bf 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3848,7 +3848,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
 			lru_add_drain();
 	}
 
-	cgroup_throttle_swaprate(page, GFP_KERNEL);
+	folio_throttle_swaprate(folio, GFP_KERNEL);
 
 	/*
 	 * Back out if somebody else already faulted in this pte.
-- 
2.35.3

[PATCH v2 3/7] mm: memory: use folio_throttle_swaprate() in page_copy_prealloc()

[Kefeng Wang]

Directly use folio_throttle_swaprate() instead of
cgroup_throttle_swaprate().

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 mm/memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memory.c b/mm/memory.c
index 948fdcd4d8bf..b5c87682bb17 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -974,7 +974,7 @@ static inline struct folio *page_copy_prealloc(struct mm_struct *src_mm,
 		folio_put(new_folio);
 		return NULL;
 	}
-	cgroup_throttle_swaprate(&new_folio->page, GFP_KERNEL);
+	folio_throttle_swaprate(new_folio, GFP_KERNEL);
 
 	return new_folio;
 }
-- 
2.35.3

[PATCH v2 4/7] mm: memory: use folio_throttle_swaprate() in wp_page_copy()

[Kefeng Wang]

Directly use folio_throttle_swaprate() instead of
cgroup_throttle_swaprate().

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 mm/memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memory.c b/mm/memory.c
index b5c87682bb17..e068635d21cf 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3096,7 +3096,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
 
 	if (mem_cgroup_charge(new_folio, mm, GFP_KERNEL))
 		goto oom_free_new;
-	cgroup_throttle_swaprate(&new_folio->page, GFP_KERNEL);
+	folio_throttle_swaprate(new_folio, GFP_KERNEL);
 
 	__folio_mark_uptodate(new_folio);
 
-- 
2.35.3

[PATCH v2 5/7] mm: memory: use folio_throttle_swaprate() in do_anonymous_page()

[Kefeng Wang]

Directly use folio_throttle_swaprate() instead of
cgroup_throttle_swaprate().

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 mm/memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memory.c b/mm/memory.c
index e068635d21cf..841737d5690d 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4065,7 +4065,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 
 	if (mem_cgroup_charge(folio, vma->vm_mm, GFP_KERNEL))
 		goto oom_free_page;
-	cgroup_throttle_swaprate(&folio->page, GFP_KERNEL);
+	folio_throttle_swaprate(folio, GFP_KERNEL);
 
 	/*
 	 * The memory barrier inside __folio_mark_uptodate makes sure that
-- 
2.35.3

[PATCH v2 6/7] mm: memory: use folio_throttle_swaprate() in do_cow_fault()

[Kefeng Wang]

Directly use folio_throttle_swaprate() instead of
cgroup_throttle_swaprate().

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 mm/memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memory.c b/mm/memory.c
index 841737d5690d..b24c618d7348 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4527,7 +4527,7 @@ static vm_fault_t do_cow_fault(struct vm_fault *vmf)
 		put_page(vmf->cow_page);
 		return VM_FAULT_OOM;
 	}
-	cgroup_throttle_swaprate(vmf->cow_page, GFP_KERNEL);
+	folio_throttle_swaprate(page_folio(vmf->cow_page), GFP_KERNEL);
 
 	ret = __do_fault(vmf);
 	if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))
-- 
2.35.3

[PATCH v2 7/7] mm: swap: remove unneeded cgroup_throttle_swaprate()

[Kefeng Wang]

All the callers of cgroup_throttle_swaprate() are converted to
folio_throttle_swaprate(), so make __cgroup_throttle_swaprate()
to take a folio, and rename it to __folio_throttle_swaprate(),
also rename gfp_mask to gfp and drop redundant extern keyword.
finally, drop unused cgroup_throttle_swaprate().

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 include/linux/swap.h | 12 ++++--------
 mm/swapfile.c        |  6 +++---
 2 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 209a425739a9..d5d0b54e90e8 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -641,22 +641,18 @@ extern atomic_t zswap_stored_pages;
 #endif
 
 #if defined(CONFIG_SWAP) && defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
-extern void __cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask);
-static inline  void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)
+void __folio_throttle_swaprate(struct folio *folio, gfp_t gfp);
+static inline void folio_throttle_swaprate(struct folio *folio, gfp_t gfp)
 {
 	if (mem_cgroup_disabled())
 		return;
-	__cgroup_throttle_swaprate(page, gfp_mask);
+	__folio_throttle_swaprate(folio, gfp);
 }
 #else
-static inline void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)
-{
-}
-#endif
 static inline void folio_throttle_swaprate(struct folio *folio, gfp_t gfp)
 {
-	cgroup_throttle_swaprate(&folio->page, gfp);
 }
+#endif
 
 #if defined(CONFIG_MEMCG) && defined(CONFIG_SWAP)
 void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 62ba2bf577d7..c1b97436f811 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -3635,12 +3635,12 @@ static void free_swap_count_continuations(struct swap_info_struct *si)
 }
 
 #if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
-void __cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)
+void __folio_throttle_swaprate(struct folio *folio, gfp_t gfp)
 {
 	struct swap_info_struct *si, *next;
-	int nid = page_to_nid(page);
+	int nid = folio_nid(folio);
 
-	if (!(gfp_mask & __GFP_IO))
+	if (!(gfp & __GFP_IO))
 		return;
 
 	if (!blk_cgroup_congested())
-- 
2.35.3

Re: [PATCH v2 0/7] mm: remove cgroup_throttle_swaprate() completely

[Matthew Wilcox]

On Thu, Mar 02, 2023 at 07:58:28PM +0800, Kefeng Wang wrote:
> Convert all the caller functions of cgroup_throttle_swaprate() to use
> folios, and use folio_throttle_swaprate(),  which allows us to remove
> cgroup_throttle_swaprate() completely.

For the series:

Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>