From 98df1c15ea2ce33e7860b85f17756ec49f648bd2 Mon Sep 17 00:00:00 2001
From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Date: Wed, 21 Mar 2012 16:33:56 -0700
Subject: [PATCH] --- yaml --- r: 292631 b: refs/heads/master c:
 b716ad953a2bc4a543143c1d9836b7007a4b182f h: refs/heads/master i:   292629:
 bc8c0105c246e6028827998a6282ad78d7a05150   292627:
 d409b43abfcd57ae7c54bd2f71b3084aab335070   292623:
 04ea745a5a38d8992d841afa306a4761901b23ac v: v3

---
 [refs]                             |  2 +-
 trunk/arch/x86/kernel/sys_x86_64.c | 34 ++++++++++++++--------------
 trunk/mm/mmap.c                    | 36 +++++++++++++++++-------------
 3 files changed, 39 insertions(+), 33 deletions(-)

diff --git a/[refs] b/[refs]
index 634397f82d46..2a16895d4ca7 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: f44d21985eb6af7361d3785e26923355172147bd
+refs/heads/master: b716ad953a2bc4a543143c1d9836b7007a4b182f
diff --git a/trunk/arch/x86/kernel/sys_x86_64.c b/trunk/arch/x86/kernel/sys_x86_64.c
index 051489082d59..ef59642ff1bf 100644
--- a/trunk/arch/x86/kernel/sys_x86_64.c
+++ b/trunk/arch/x86/kernel/sys_x86_64.c
@@ -195,7 +195,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 {
 	struct vm_area_struct *vma;
 	struct mm_struct *mm = current->mm;
-	unsigned long addr = addr0;
+	unsigned long addr = addr0, start_addr;
 
 	/* requested length too big for entire address space */
 	if (len > TASK_SIZE)
@@ -223,25 +223,14 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 		mm->free_area_cache = mm->mmap_base;
 	}
 
+try_again:
 	/* either no address requested or can't fit in requested address hole */
-	addr = mm->free_area_cache;
-
-	/* make sure it can fit in the remaining address space */
-	if (addr > len) {
-		unsigned long tmp_addr = align_addr(addr - len, filp,
-						    ALIGN_TOPDOWN);
-
-		vma = find_vma(mm, tmp_addr);
-		if (!vma || tmp_addr + len <= vma->vm_start)
-			/* remember the address as a hint for next time */
-			return mm->free_area_cache = tmp_addr;
-	}
-
-	if (mm->mmap_base < len)
-		goto bottomup;
+	start_addr = addr = mm->free_area_cache;
 
-	addr = mm->mmap_base-len;
+	if (addr < len)
+		goto fail;
 
+	addr -= len;
 	do {
 		addr = align_addr(addr, filp, ALIGN_TOPDOWN);
 
@@ -263,6 +252,17 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 		addr = vma->vm_start-len;
 	} while (len < vma->vm_start);
 
+fail:
+	/*
+	 * if hint left us with no space for the requested
+	 * mapping then try again:
+	 */
+	if (start_addr != mm->mmap_base) {
+		mm->free_area_cache = mm->mmap_base;
+		mm->cached_hole_size = 0;
+		goto try_again;
+	}
+
 bottomup:
 	/*
 	 * A failed mmap() very likely causes application failure,
diff --git a/trunk/mm/mmap.c b/trunk/mm/mmap.c
index 4f31764d838f..9e0c0de2e7e3 100644
--- a/trunk/mm/mmap.c
+++ b/trunk/mm/mmap.c
@@ -1442,7 +1442,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 {
 	struct vm_area_struct *vma;
 	struct mm_struct *mm = current->mm;
-	unsigned long addr = addr0;
+	unsigned long addr = addr0, start_addr;
 
 	/* requested length too big for entire address space */
 	if (len > TASK_SIZE)
@@ -1466,22 +1466,14 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
  		mm->free_area_cache = mm->mmap_base;
  	}
 
+try_again:
 	/* either no address requested or can't fit in requested address hole */
-	addr = mm->free_area_cache;
+	start_addr = addr = mm->free_area_cache;
 
-	/* make sure it can fit in the remaining address space */
-	if (addr > len) {
-		vma = find_vma(mm, addr-len);
-		if (!vma || addr <= vma->vm_start)
-			/* remember the address as a hint for next time */
-			return (mm->free_area_cache = addr-len);
-	}
-
-	if (mm->mmap_base < len)
-		goto bottomup;
-
-	addr = mm->mmap_base-len;
+	if (addr < len)
+		goto fail;
 
+	addr -= len;
 	do {
 		/*
 		 * Lookup failure means no vma is above this address,
@@ -1501,7 +1493,21 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 		addr = vma->vm_start-len;
 	} while (len < vma->vm_start);
 
-bottomup:
+fail:
+	/*
+	 * if hint left us with no space for the requested
+	 * mapping then try again:
+	 *
+	 * Note: this is different with the case of bottomup
+	 * which does the fully line-search, but we use find_vma
+	 * here that causes some holes skipped.
+	 */
+	if (start_addr != mm->mmap_base) {
+		mm->free_area_cache = mm->mmap_base;
+		mm->cached_hole_size = 0;
+		goto try_again;
+	}
+
 	/*
 	 * A failed mmap() very likely causes application failure,
 	 * so fall back to the bottom-up function here. This scenario