Initial import

1 files changed, 146 insertions, 0 deletions

diff --git a/include/linux/uksm.h b/include/linux/uksm.h
new file mode 100644
index 000000000..206f10958
--- /dev/null
+++ b/include/linux/uksm.h
@@ -0,0 +1,146 @@
+#ifndef __LINUX_UKSM_H
+#define __LINUX_UKSM_H
+/*
+ * Memory merging support.
+ *
+ * This code enables dynamic sharing of identical pages found in different
+ * memory areas, even if they are not shared by fork().
+ */
+
+/* if !CONFIG_UKSM this file should not be compiled at all. */
+#ifdef CONFIG_UKSM
+
+#include <linux/bitops.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/rmap.h>
+#include <linux/sched.h>
+
+extern unsigned long zero_pfn __read_mostly;
+extern unsigned long uksm_zero_pfn __read_mostly;
+extern struct page *empty_uksm_zero_page;
+
+/* must be done before linked to mm */
+extern void uksm_vma_add_new(struct vm_area_struct *vma);
+extern void uksm_remove_vma(struct vm_area_struct *vma);
+
+#define UKSM_SLOT_NEED_SORT	(1 << 0)
+#define UKSM_SLOT_NEED_RERAND 	(1 << 1)
+#define UKSM_SLOT_SCANNED     	(1 << 2) /* It's scanned in this round */
+#define UKSM_SLOT_FUL_SCANNED 	(1 << 3)
+#define UKSM_SLOT_IN_UKSM 	(1 << 4)
+
+struct vma_slot {
+	struct sradix_tree_node *snode;
+	unsigned long sindex;
+
+	struct list_head slot_list;
+	unsigned long fully_scanned_round;
+	unsigned long dedup_num;
+	unsigned long pages_scanned;
+	unsigned long last_scanned;
+	unsigned long pages_to_scan;
+	struct scan_rung *rung;
+	struct page **rmap_list_pool;
+	unsigned int *pool_counts;
+	unsigned long pool_size;
+	struct vm_area_struct *vma;
+	struct mm_struct *mm;
+	unsigned long ctime_j;
+	unsigned long pages;
+	unsigned long flags;
+	unsigned long pages_cowed; /* pages cowed this round */
+	unsigned long pages_merged; /* pages merged this round */
+	unsigned long pages_bemerged;
+
+	/* when it has page merged in this eval round */
+	struct list_head dedup_list;
+};
+
+static inline void uksm_unmap_zero_page(pte_t pte)
+{
+	if (pte_pfn(pte) == uksm_zero_pfn)
+		__dec_zone_page_state(empty_uksm_zero_page, NR_UKSM_ZERO_PAGES);
+}
+
+static inline void uksm_map_zero_page(pte_t pte)
+{
+	if (pte_pfn(pte) == uksm_zero_pfn)
+		__inc_zone_page_state(empty_uksm_zero_page, NR_UKSM_ZERO_PAGES);
+}
+
+static inline void uksm_cow_page(struct vm_area_struct *vma, struct page *page)
+{
+	if (vma->uksm_vma_slot && PageKsm(page))
+		vma->uksm_vma_slot->pages_cowed++;
+}
+
+static inline void uksm_cow_pte(struct vm_area_struct *vma, pte_t pte)
+{
+	if (vma->uksm_vma_slot && pte_pfn(pte) == uksm_zero_pfn)
+		vma->uksm_vma_slot->pages_cowed++;
+}
+
+static inline int uksm_flags_can_scan(unsigned long vm_flags)
+{
+#ifndef VM_SAO
+#define VM_SAO 0
+#endif
+	return !(vm_flags & (VM_PFNMAP | VM_IO  | VM_DONTEXPAND |
+			     VM_HUGETLB | VM_MIXEDMAP | VM_SHARED
+			     | VM_MAYSHARE | VM_GROWSUP | VM_GROWSDOWN | VM_SAO));
+}
+
+static inline void uksm_vm_flags_mod(unsigned long *vm_flags_p)
+{
+	if (uksm_flags_can_scan(*vm_flags_p))
+		*vm_flags_p |= VM_MERGEABLE;
+}
+
+/*
+ * Just a wrapper for BUG_ON for where ksm_zeropage must not be. TODO: it will
+ * be removed when uksm zero page patch is stable enough.
+ */
+static inline void uksm_bugon_zeropage(pte_t pte)
+{
+	BUG_ON(pte_pfn(pte) == uksm_zero_pfn);
+}
+#else
+static inline void uksm_vma_add_new(struct vm_area_struct *vma)
+{
+}
+
+static inline void uksm_remove_vma(struct vm_area_struct *vma)
+{
+}
+
+static inline void uksm_unmap_zero_page(pte_t pte)
+{
+}
+
+static inline void uksm_map_zero_page(pte_t pte)
+{
+}
+
+static inline void uksm_cow_page(struct vm_area_struct *vma, struct page *page)
+{
+}
+
+static inline void uksm_cow_pte(struct vm_area_struct *vma, pte_t pte)
+{
+}
+
+static inline int uksm_flags_can_scan(unsigned long vm_flags)
+{
+	return 0;
+}
+
+static inline void uksm_vm_flags_mod(unsigned long *vm_flags_p)
+{
+}
+
+static inline void uksm_bugon_zeropage(pte_t pte)
+{
+}
+#endif /* !CONFIG_UKSM */
+#endif /* __LINUX_UKSM_H */