mm: convert mm_counter_file() to take a folio

Now all callers of mm_counter_file() have a folio, convert
mm_counter_file() to take a folio.  Saves a call to compound_head() hidden
inside PageSwapBacked().

Link: https://lkml.kernel.org/r/20240111152429.3374566-11-willy@infradead.org
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: Kefeng Wang

include/linux/mm.h

@@ -2595,10 +2595,10 @@ static inline void dec_mm_counter(struct mm_struct *mm, int member)
 	mm_trace_rss_stat(mm, member);
 }
 
-/* Optimized variant when page is already known not to be PageAnon */
-static inline int mm_counter_file(struct page *page)
+/* Optimized variant when folio is already known not to be anon */
+static inline int mm_counter_file(struct folio *folio)
 {
-	if (PageSwapBacked(page))
+	if (folio_test_swapbacked(folio))
 		return MM_SHMEMPAGES;
 	return MM_FILEPAGES;
 }
@@ -2607,7 +2607,7 @@ static inline int mm_counter(struct folio *folio)
 {
 	if (folio_test_anon(folio))
 		return MM_ANONPAGES;
-	return mm_counter_file(&folio->page);
+	return mm_counter_file(folio);
 }
 
 static inline unsigned long get_mm_rss(struct mm_struct *mm)

kernel/events/uprobes.c

@@ -188,7 +188,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
 		dec_mm_counter(mm, MM_ANONPAGES);
 
 	if (!folio_test_anon(old_folio)) {
-		dec_mm_counter(mm, mm_counter_file(old_page));
+		dec_mm_counter(mm, mm_counter_file(old_folio));
 		inc_mm_counter(mm, MM_ANONPAGES);
 	}
 

mm/huge_memory.c

@@ -1931,7 +1931,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 		} else {
 			if (arch_needs_pgtable_deposit())
 				zap_deposited_table(tlb->mm, pmd);
-			add_mm_counter(tlb->mm, mm_counter_file(&folio->page),
+			add_mm_counter(tlb->mm, mm_counter_file(folio),
 				       -HPAGE_PMD_NR);
 		}
 
@@ -2456,7 +2456,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
 			folio_remove_rmap_pmd(folio, page, vma);
 			folio_put(folio);
 		}
-		add_mm_counter(mm, mm_counter_file(&folio->page), -HPAGE_PMD_NR);
+		add_mm_counter(mm, mm_counter_file(folio), -HPAGE_PMD_NR);
 		return;
 	}
 

mm/khugepaged.c

@@ -1634,7 +1634,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr,
 	/* step 3: set proper refcount and mm_counters. */
 	if (nr_ptes) {
 		folio_ref_sub(folio, nr_ptes);
-		add_mm_counter(mm, mm_counter_file(&folio->page), -nr_ptes);
+		add_mm_counter(mm, mm_counter_file(folio), -nr_ptes);
 	}
 
 	/* step 4: remove empty page table */
@@ -1665,7 +1665,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr,
 	if (nr_ptes) {
 		flush_tlb_mm(mm);
 		folio_ref_sub(folio, nr_ptes);
-		add_mm_counter(mm, mm_counter_file(&folio->page), -nr_ptes);
+		add_mm_counter(mm, mm_counter_file(folio), -nr_ptes);
 	}
 	if (start_pte)
 		pte_unmap_unlock(start_pte, ptl);

mm/memory.c

@@ -966,7 +966,7 @@ copy_present_pte(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma,
 	} else if (page) {
 		folio_get(folio);
 		folio_dup_file_rmap_pte(folio, page);
-		rss[mm_counter_file(page)]++;
+		rss[mm_counter_file(folio)]++;
 	}
 
 	/*
@@ -1873,7 +1873,7 @@ static int insert_page_into_pte_locked(struct vm_area_struct *vma, pte_t *pte,
 		return -EBUSY;
 	/* Ok, finally just insert the thing.. */
 	folio_get(folio);
-	inc_mm_counter(vma->vm_mm, mm_counter_file(page));
+	inc_mm_counter(vma->vm_mm, mm_counter_file(folio));
 	folio_add_file_rmap_pte(folio, page, vma);
 	set_pte_at(vma->vm_mm, addr, pte, mk_pte(page, prot));
 	return 0;
@@ -3178,7 +3178,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
 	if (likely(vmf->pte && pte_same(ptep_get(vmf->pte), vmf->orig_pte))) {
 		if (old_folio) {
 			if (!folio_test_anon(old_folio)) {
-				dec_mm_counter(mm, mm_counter_file(&old_folio->page));
+				dec_mm_counter(mm, mm_counter_file(old_folio));
 				inc_mm_counter(mm, MM_ANONPAGES);
 			}
 		} else {
@@ -4483,7 +4483,7 @@ vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page)
 	if (write)
 		entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
 
-	add_mm_counter(vma->vm_mm, mm_counter_file(page), HPAGE_PMD_NR);
+	add_mm_counter(vma->vm_mm, mm_counter_file(folio), HPAGE_PMD_NR);
 	folio_add_file_rmap_pmd(folio, page, vma);
 
 	/*
@@ -4546,7 +4546,7 @@ void set_pte_range(struct vm_fault *vmf, struct folio *folio,
 		folio_add_new_anon_rmap(folio, vma, addr);
 		folio_add_lru_vma(folio, vma);
 	} else {
-		add_mm_counter(vma->vm_mm, mm_counter_file(page), nr);
+		add_mm_counter(vma->vm_mm, mm_counter_file(folio), nr);
 		folio_add_file_rmap_ptes(folio, page, nr, vma);
 	}
 	set_ptes(vma->vm_mm, addr, vmf->pte, entry, nr);

mm/rmap.c

@@ -1903,7 +1903,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
 			 *
 			 * See Documentation/mm/mmu_notifier.rst
 			 */
-			dec_mm_counter(mm, mm_counter_file(&folio->page));
+			dec_mm_counter(mm, mm_counter_file(folio));
 		}
 discard:
 		if (unlikely(folio_test_hugetlb(folio)))