3 files changed, 33 insertions, 30 deletions

diff --git a/mm/Kconfig b/mm/Kconfig
index edd300aca17..57963c6063d 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -224,7 +224,9 @@ config KSM
           the many instances by a single resident page with that content, so
           saving memory until one or another app needs to modify the content.
           Recommended for use with KVM, or with other duplicative applications.
-          See Documentation/vm/ksm.txt for more information.
+          See Documentation/vm/ksm.txt for more information: KSM is inactive
+          until a program has madvised that an area is MADV_MERGEABLE, and
+          root has set /sys/kernel/mm/ksm/run to 1 (if CONFIG_SYSFS is set).
 
 config DEFAULT_MMAP_MIN_ADDR
         int "Low address space to protect from user allocation"
diff --git a/mm/ksm.c b/mm/ksm.c
index f7edac356f4..bef1af4f77e 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -184,11 +184,6 @@ static DEFINE_SPINLOCK(ksm_mmlist_lock);
                 sizeof(struct __struct), __alignof__(struct __struct),\
                 (__flags), NULL)
 
-static void __init ksm_init_max_kernel_pages(void)
-{
-        ksm_max_kernel_pages = nr_free_buffer_pages() / 4;
-}
-
 static int __init ksm_slab_init(void)
 {
         rmap_item_cache = KSM_KMEM_CACHE(rmap_item, 0);
@@ -1673,7 +1668,7 @@ static int __init ksm_init(void)
         struct task_struct *ksm_thread;
         int err;
 
-        ksm_init_max_kernel_pages();
+        ksm_max_kernel_pages = totalram_pages / 4;
 
         err = ksm_slab_init();
         if (err)
@@ -1697,6 +1692,9 @@ static int __init ksm_init(void)
                 kthread_stop(ksm_thread);
                 goto out_free2;
         }
+#else
+        ksm_run = KSM_RUN_MERGE;        /* no way for user to start it */
+
 #endif /* CONFIG_SYSFS */
 
         return 0;
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 69511e66323..5e7aed0802b 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -25,10 +25,10 @@
 #include <linux/rcupdate.h>
 #include <linux/pfn.h>
 #include <linux/kmemleak.h>
-#include <linux/highmem.h>
 #include <asm/atomic.h>
 #include <asm/uaccess.h>
 #include <asm/tlbflush.h>
+#include <asm/shmparam.h>
 
 
 /*** Page table manipulation functions ***/
@@ -1156,12 +1156,11 @@ static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
 }
 
 static struct vm_struct *__get_vm_area_node(unsigned long size,
-                unsigned long flags, unsigned long start, unsigned long end,
-                int node, gfp_t gfp_mask, void *caller)
+                unsigned long align, unsigned long flags, unsigned long start,
+                unsigned long end, int node, gfp_t gfp_mask, void *caller)
 {
         static struct vmap_area *va;
         struct vm_struct *area;
-        unsigned long align = 1;
 
         BUG_ON(in_interrupt());
         if (flags & VM_IOREMAP) {
@@ -1201,7 +1200,7 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,
 struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
                                 unsigned long start, unsigned long end)
 {
-        return __get_vm_area_node(size, flags, start, end, -1, GFP_KERNEL,
+        return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
                                                 __builtin_return_address(0));
 }
 EXPORT_SYMBOL_GPL(__get_vm_area);
@@ -1210,7 +1209,7 @@ struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
                                        unsigned long start, unsigned long end,
                                        void *caller)
 {
-        return __get_vm_area_node(size, flags, start, end, -1, GFP_KERNEL,
+        return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
                                   caller);
 }
 
@@ -1225,22 +1224,22 @@ struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
  */
 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
 {
-        return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END,
+        return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
                                 -1, GFP_KERNEL, __builtin_return_address(0));
 }
 
 struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
                                 void *caller)
 {
-        return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END,
+        return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
                                                 -1, GFP_KERNEL, caller);
 }
 
 struct vm_struct *get_vm_area_node(unsigned long size, unsigned long flags,
                                    int node, gfp_t gfp_mask)
 {
-        return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END, node,
-                                  gfp_mask, __builtin_return_address(0));
+        return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
+                                  node, gfp_mask, __builtin_return_address(0));
 }
 
 static struct vm_struct *find_vm_area(const void *addr)
@@ -1403,7 +1402,8 @@ void *vmap(struct page **pages, unsigned int count,
 }
 EXPORT_SYMBOL(vmap);
 
-static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
+static void *__vmalloc_node(unsigned long size, unsigned long align,
+                            gfp_t gfp_mask, pgprot_t prot,
                             int node, void *caller);
 static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
                                  pgprot_t prot, int node, void *caller)
@@ -1417,7 +1417,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
         area->nr_pages = nr_pages;
         /* Please note that the recursion is strictly bounded. */
         if (array_size > PAGE_SIZE) {
-                pages = __vmalloc_node(array_size, gfp_mask | __GFP_ZERO,
+                pages = __vmalloc_node(array_size, 1, gfp_mask | __GFP_ZERO,
                                 PAGE_KERNEL, node, caller);
                 area->flags |= VM_VPAGES;
         } else {
@@ -1476,6 +1476,7 @@ void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot)
 /**
  *      __vmalloc_node  -  allocate virtually contiguous memory
  *      @size:          allocation size
+ *      @align:         desired alignment
  *      @gfp_mask:      flags for the page level allocator
  *      @prot:          protection mask for the allocated pages
  *      @node:          node to use for allocation or -1
@@ -1485,8 +1486,9 @@ void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot)
  *      allocator with @gfp_mask flags.  Map them into contiguous
  *      kernel virtual space, using a pagetable protection of @prot.
  */
-static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
-                                                int node, void *caller)
+static void *__vmalloc_node(unsigned long size, unsigned long align,
+                            gfp_t gfp_mask, pgprot_t prot,
+                            int node, void *caller)
 {
         struct vm_struct *area;
         void *addr;
@@ -1496,8 +1498,8 @@ static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
         if (!size || (size >> PAGE_SHIFT) > totalram_pages)
                 return NULL;
 
-        area = __get_vm_area_node(size, VM_ALLOC, VMALLOC_START, VMALLOC_END,
-                                                node, gfp_mask, caller);
+        area = __get_vm_area_node(size, align, VM_ALLOC, VMALLOC_START,
+                                  VMALLOC_END, node, gfp_mask, caller);
 
         if (!area)
                 return NULL;
@@ -1516,7 +1518,7 @@ static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
 
 void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
 {
-        return __vmalloc_node(size, gfp_mask, prot, -1,
+        return __vmalloc_node(size, 1, gfp_mask, prot, -1,
                                 __builtin_return_address(0));
 }
 EXPORT_SYMBOL(__vmalloc);
@@ -1532,7 +1534,7 @@ EXPORT_SYMBOL(__vmalloc);
  */
 void *vmalloc(unsigned long size)
 {
-        return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
+        return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
                                         -1, __builtin_return_address(0));
 }
 EXPORT_SYMBOL(vmalloc);
@@ -1549,7 +1551,8 @@ void *vmalloc_user(unsigned long size)
         struct vm_struct *area;
         void *ret;
 
-        ret = __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
+        ret = __vmalloc_node(size, SHMLBA,
+                             GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
                              PAGE_KERNEL, -1, __builtin_return_address(0));
         if (ret) {
                 area = find_vm_area(ret);
@@ -1572,7 +1575,7 @@ EXPORT_SYMBOL(vmalloc_user);
  */
 void *vmalloc_node(unsigned long size, int node)
 {
-        return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
+        return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
                                         node, __builtin_return_address(0));
 }
 EXPORT_SYMBOL(vmalloc_node);
@@ -1595,7 +1598,7 @@ EXPORT_SYMBOL(vmalloc_node);
 
 void *vmalloc_exec(unsigned long size)
 {
-        return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
+        return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
                               -1, __builtin_return_address(0));
 }
 
@@ -1616,7 +1619,7 @@ void *vmalloc_exec(unsigned long size)
  */
 void *vmalloc_32(unsigned long size)
 {
-        return __vmalloc_node(size, GFP_VMALLOC32, PAGE_KERNEL,
+        return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
                               -1, __builtin_return_address(0));
 }
 EXPORT_SYMBOL(vmalloc_32);
@@ -1633,7 +1636,7 @@ void *vmalloc_32_user(unsigned long size)
         struct vm_struct *area;
         void *ret;
 
-        ret = __vmalloc_node(size, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
+        ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
                              -1, __builtin_return_address(0));
         if (ret) {
                 area = find_vm_area(ret);