1 files changed, 79 insertions, 15 deletions

diff --git a/include/linux/ksm.h b/include/linux/ksm.h
index 161e8164abcf..d73095b5cd96 100644
--- a/include/linux/ksm.h
+++ b/include/linux/ksm.h
@@ -13,21 +13,58 @@
 #include <linux/pagemap.h>
 #include <linux/rmap.h>
 #include <linux/sched.h>
-#include <linux/sched/coredump.h>
-
-struct stable_node;
-struct mem_cgroup;
 
 #ifdef CONFIG_KSM
 int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
 		unsigned long end, int advice, unsigned long *vm_flags);
+
+void ksm_add_vma(struct vm_area_struct *vma);
+int ksm_enable_merge_any(struct mm_struct *mm);
+int ksm_disable_merge_any(struct mm_struct *mm);
+int ksm_disable(struct mm_struct *mm);
+
 int __ksm_enter(struct mm_struct *mm);
 void __ksm_exit(struct mm_struct *mm);
+/*
+ * To identify zeropages that were mapped by KSM, we reuse the dirty bit
+ * in the PTE. If the PTE is dirty, the zeropage was mapped by KSM when
+ * deduplicating memory.
+ */
+#define is_ksm_zero_pte(pte)	(is_zero_pfn(pte_pfn(pte)) && pte_dirty(pte))
+
+extern atomic_long_t ksm_zero_pages;
+
+static inline void ksm_map_zero_page(struct mm_struct *mm)
+{
+	atomic_long_inc(&ksm_zero_pages);
+	atomic_long_inc(&mm->ksm_zero_pages);
+}
 
-static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm)
+static inline void ksm_might_unmap_zero_page(struct mm_struct *mm, pte_t pte)
 {
+	if (is_ksm_zero_pte(pte)) {
+		atomic_long_dec(&ksm_zero_pages);
+		atomic_long_dec(&mm->ksm_zero_pages);
+	}
+}
+
+static inline long mm_ksm_zero_pages(struct mm_struct *mm)
+{
+	return atomic_long_read(&mm->ksm_zero_pages);
+}
+
+static inline void ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm)
+{
+	/* Adding mm to ksm is best effort on fork. */
 	if (test_bit(MMF_VM_MERGEABLE, &oldmm->flags))
+		__ksm_enter(mm);
+}
+
+static inline int ksm_execve(struct mm_struct *mm)
+{
+	if (test_bit(MMF_VM_MERGE_ANY, &mm->flags))
 		return __ksm_enter(mm);
+
 	return 0;
 }
 
@@ -48,15 +85,32 @@ static inline void ksm_exit(struct mm_struct *mm)
  * We'd like to make this conditional on vma->vm_flags & VM_MERGEABLE,
  * but what if the vma was unmerged while the page was swapped out?
  */
-struct page *ksm_might_need_to_copy(struct page *page,
-			struct vm_area_struct *vma, unsigned long address);
+struct folio *ksm_might_need_to_copy(struct folio *folio,
+			struct vm_area_struct *vma, unsigned long addr);
 
-void rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc);
-void ksm_migrate_page(struct page *newpage, struct page *oldpage);
+void rmap_walk_ksm(struct folio *folio, struct rmap_walk_control *rwc);
+void folio_migrate_ksm(struct folio *newfolio, struct folio *folio);
+void collect_procs_ksm(const struct folio *folio, const struct page *page,
+		struct list_head *to_kill, int force_early);
+long ksm_process_profit(struct mm_struct *);
+bool ksm_process_mergeable(struct mm_struct *mm);
 
 #else  /* !CONFIG_KSM */
 
-static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm)
+static inline void ksm_add_vma(struct vm_area_struct *vma)
+{
+}
+
+static inline int ksm_disable(struct mm_struct *mm)
+{
+	return 0;
+}
+
+static inline void ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm)
+{
+}
+
+static inline int ksm_execve(struct mm_struct *mm)
 {
 	return 0;
 }
@@ -65,6 +119,16 @@ static inline void ksm_exit(struct mm_struct *mm)
 {
 }
 
+static inline void ksm_might_unmap_zero_page(struct mm_struct *mm, pte_t pte)
+{
+}
+
+static inline void collect_procs_ksm(const struct folio *folio,
+		const struct page *page, struct list_head *to_kill,
+		int force_early)
+{
+}
+
 #ifdef CONFIG_MMU
 static inline int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
 		unsigned long end, int advice, unsigned long *vm_flags)
@@ -72,18 +136,18 @@ static inline int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
 	return 0;
 }
 
-static inline struct page *ksm_might_need_to_copy(struct page *page,
-			struct vm_area_struct *vma, unsigned long address)
+static inline struct folio *ksm_might_need_to_copy(struct folio *folio,
+			struct vm_area_struct *vma, unsigned long addr)
 {
-	return page;
+	return folio;
 }
 
-static inline void rmap_walk_ksm(struct page *page,
+static inline void rmap_walk_ksm(struct folio *folio,
 			struct rmap_walk_control *rwc)
 {
 }
 
-static inline void ksm_migrate_page(struct page *newpage, struct page *oldpage)
+static inline void folio_migrate_ksm(struct folio *newfolio, struct folio *old)
 {
 }
 #endif /* CONFIG_MMU */