From 7219c6b566d65956a731c08db360cfada15156e8 Mon Sep 17 00:00:00 2001
From: Johannes Weiner <hannes@cmpxchg.org>
Date: Thu, 13 Jan 2011 15:47:02 -0800
Subject: [PATCH] --- yaml --- r: 230786 b: refs/heads/master c:
 0ca1634d4143c3579273ca53b993df19f5c98e92 h: refs/heads/master v: v3

---
 [refs]                        |  2 +-
 trunk/include/linux/huge_mm.h |  3 +++
 trunk/mm/huge_memory.c        | 25 +++++++++++++++++++++++++
 trunk/mm/mincore.c            |  8 +++++++-
 4 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 7455f5575082..67834ce97c9d 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: f2d6bfe9ff0acec30b713614260e78b03d20e909
+refs/heads/master: 0ca1634d4143c3579273ca53b993df19f5c98e92
diff --git a/trunk/include/linux/huge_mm.h b/trunk/include/linux/huge_mm.h
index 43a694ef8904..25125fb6acf7 100644
--- a/trunk/include/linux/huge_mm.h
+++ b/trunk/include/linux/huge_mm.h
@@ -19,6 +19,9 @@ extern struct page *follow_trans_huge_pmd(struct mm_struct *mm,
 extern int zap_huge_pmd(struct mmu_gather *tlb,
 			struct vm_area_struct *vma,
 			pmd_t *pmd);
+extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
+			unsigned long addr, unsigned long end,
+			unsigned char *vec);
 
 enum transparent_hugepage_flag {
 	TRANSPARENT_HUGEPAGE_FLAG,
diff --git a/trunk/mm/huge_memory.c b/trunk/mm/huge_memory.c
index ae2bf08b1099..37e89a32a0b1 100644
--- a/trunk/mm/huge_memory.c
+++ b/trunk/mm/huge_memory.c
@@ -923,6 +923,31 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 	return ret;
 }
 
+int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
+		unsigned long addr, unsigned long end,
+		unsigned char *vec)
+{
+	int ret = 0;
+
+	spin_lock(&vma->vm_mm->page_table_lock);
+	if (likely(pmd_trans_huge(*pmd))) {
+		ret = !pmd_trans_splitting(*pmd);
+		spin_unlock(&vma->vm_mm->page_table_lock);
+		if (unlikely(!ret))
+			wait_split_huge_page(vma->anon_vma, pmd);
+		else {
+			/*
+			 * All logical pages in the range are present
+			 * if backed by a huge page.
+			 */
+			memset(vec, 1, (end - addr) >> PAGE_SHIFT);
+		}
+	} else
+		spin_unlock(&vma->vm_mm->page_table_lock);
+
+	return ret;
+}
+
 pmd_t *page_check_address_pmd(struct page *page,
 			      struct mm_struct *mm,
 			      unsigned long address,
diff --git a/trunk/mm/mincore.c b/trunk/mm/mincore.c
index 9959bb41570e..a4e6b9d75c76 100644
--- a/trunk/mm/mincore.c
+++ b/trunk/mm/mincore.c
@@ -154,7 +154,13 @@ static void mincore_pmd_range(struct vm_area_struct *vma, pud_t *pud,
 	pmd = pmd_offset(pud, addr);
 	do {
 		next = pmd_addr_end(addr, end);
-		split_huge_page_pmd(vma->vm_mm, pmd);
+		if (pmd_trans_huge(*pmd)) {
+			if (mincore_huge_pmd(vma, pmd, addr, next, vec)) {
+				vec += (next - addr) >> PAGE_SHIFT;
+				continue;
+			}
+			/* fall through */
+		}
 		if (pmd_none_or_clear_bad(pmd))
 			mincore_unmapped_range(vma, addr, next, vec);
 		else