[PATCH 075/166] migrate: consolidate MPOL_MF_SW_YOUNG behaviors

[Fengguang Wu]

- if page already in target node: SetPageReferenced
- otherwise: change_prot_numa

Signed-off-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
---
 arch/x86/kvm/Kconfig |  1 +
 mm/migrate.c         | 65 +++++++++++++++++++++++++++++++---------------------
 2 files changed, 40 insertions(+), 26 deletions(-)

diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index 4c6dec47fac6..c103373536fc 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -100,6 +100,7 @@ config KVM_EPT_IDLE
 	tristate "KVM EPT idle page tracking"
 	depends on KVM_INTEL
 	depends on PROC_PAGE_MONITOR
+	depends on NUMA_BALANCING
 	---help---
 	  Provides support for walking EPT to get the A bits on Intel
 	  processors equipped with the VT extensions.
diff --git a/mm/migrate.c b/mm/migrate.c
index d933f6966601..d944f031c9ea 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1500,6 +1500,8 @@ static int add_page_for_migration(struct mm_struct *mm, unsigned long addr,
 {
 	struct vm_area_struct *vma;
 	struct page *page;
+	unsigned long end;
+	unsigned int page_nid;
 	unsigned int follflags;
 	int err;
 	bool migrate_all = flags & MPOL_MF_MOVE_ALL;
@@ -1522,49 +1524,60 @@ static int add_page_for_migration(struct mm_struct *mm, unsigned long addr,
 	if (!page)
 		goto out;
 
-	err = 0;
-	if (page_to_nid(page) == node)
-		goto out_putpage;
+	page_nid = page_to_nid(page);
 
 	err = -EACCES;
 	if (page_mapcount(page) > 1 && !migrate_all)
 		goto out_putpage;
 
-	if (flags & MPOL_MF_SW_YOUNG) {
-		unsigned long start, end;
-		unsigned long nr_pte_updates = 0;
-
-		start = max(addr, vma->vm_start);
-
-		/* TODO: if huge page  */
-		end = ALIGN(addr + (1 << PAGE_SHIFT), PAGE_SIZE);
-		end = min(end, vma->vm_end);
-		nr_pte_updates = change_prot_numa(vma, start, end);
-
-		err = 0;
-		goto out_putpage;
-	}
-
+	err = 0;
 	if (PageHuge(page)) {
-		if (PageHead(page)) {
-			/* Check if the page is software young. */
-			if (flags & MPOL_MF_SW_YOUNG)
+		if (!PageHead(page)) {
+			err = -EACCES;
+			goto out_putpage;
+		}
+		if (flags & MPOL_MF_SW_YOUNG) {
+			if (page_nid == node)
 				SetPageReferenced(page);
-			isolate_huge_page(page, pagelist);
-			err = 0;
+			else if (PageAnon(page)) {
+				end = addr + (hpage_nr_pages(page) << PAGE_SHIFT);
+				if (end <= vma->vm_end)
+					change_prot_numa(vma, addr, end);
+			}
+			goto out_putpage;
 		}
+		if (page_nid == node)
+			goto out_putpage;
+		isolate_huge_page(page, pagelist);
 	} else {
 		struct page *head;
 
 		head = compound_head(page);
+
+		if (flags & MPOL_MF_SW_YOUNG) {
+			if (page_nid == node)
+				SetPageReferenced(head);
+			else {
+				unsigned long size;
+				size = hpage_nr_pages(head) << PAGE_SHIFT;
+				end = addr + size;
+				if (unlikely(addr & (size - 1)))
+					err = -EXDEV;
+				else if (likely(end <= vma->vm_end))
+					change_prot_numa(vma, addr, end);
+				else
+					err = -ERANGE;
+			}
+			goto out_putpage;
+		}
+		if (page_nid == node)
+			goto out_putpage;
+
 		err = isolate_lru_page(head);
 		if (err)
 			goto out_putpage;
 
 		err = 0;
-		/* Check if the page is software young. */
-		if (flags & MPOL_MF_SW_YOUNG)
-			SetPageReferenced(head);
 		list_add_tail(&head->lru, pagelist);
 		mod_node_page_state(page_pgdat(head),
 			NR_ISOLATED_ANON + page_is_file_cache(head),
-- 
2.15.0


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Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment; filename="0076-mempolicy-force-NUMA-balancing.patch"