Do not account for the address space used by hugetlbfs using VM_ACCOUNT

[linux-flexiantxendom0-natty.git] / mm / mmap.c

diff --git a/mm/mmap.c b/mm/mmap.c
index 214b6a2..eb1270b 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -918,7 +918,6 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
        struct inode *inode;
        unsigned int vm_flags;
        int error;
-       int accountable = 1;
        unsigned long reqprot = prot;
 
        /*
@@ -1019,8 +1018,6 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
                                        return -EPERM;
                                vm_flags &= ~VM_MAYEXEC;
                        }
-                       if (is_file_hugepages(file))
-                               accountable = 0;
 
                        if (!file->f_op || !file->f_op->mmap)
                                return -ENODEV;
@@ -1053,8 +1050,7 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
        if (error)
                return error;
 
-       return mmap_region(file, addr, len, flags, vm_flags, pgoff,
-                          accountable);
+       return mmap_region(file, addr, len, flags, vm_flags, pgoff);
 }
 EXPORT_SYMBOL(do_mmap_pgoff);
 
@@ -1092,17 +1088,23 @@ int vma_wants_writenotify(struct vm_area_struct *vma)
 
 /*
  * We account for memory if it's a private writeable mapping,
- * and VM_NORESERVE wasn't set.
+ * not hugepages and VM_NORESERVE wasn't set.
  */
-static inline int accountable_mapping(unsigned int vm_flags)
+static inline int accountable_mapping(struct file *file, unsigned int vm_flags)
 {
+       /*
+        * hugetlb has its own accounting separate from the core VM
+        * VM_HUGETLB may not be set yet so we cannot check for that flag.
+        */
+       if (file && is_file_hugepages(file))
+               return 0;
+
        return (vm_flags & (VM_NORESERVE | VM_SHARED | VM_WRITE)) == VM_WRITE;
 }
 
 unsigned long mmap_region(struct file *file, unsigned long addr,
                          unsigned long len, unsigned long flags,
-                         unsigned int vm_flags, unsigned long pgoff,
-                         int accountable)
+                         unsigned int vm_flags, unsigned long pgoff)
 {
        struct mm_struct *mm = current->mm;
        struct vm_area_struct *vma, *prev;
@@ -1128,18 +1130,22 @@ munmap_back:
 
        /*
         * Set 'VM_NORESERVE' if we should not account for the
-        * memory use of this mapping. We only honor MAP_NORESERVE
-        * if we're allowed to overcommit memory.
+        * memory use of this mapping.
         */
-       if ((flags & MAP_NORESERVE) && sysctl_overcommit_memory != OVERCOMMIT_NEVER)
-               vm_flags |= VM_NORESERVE;
-       if (!accountable)
-               vm_flags |= VM_NORESERVE;
+       if ((flags & MAP_NORESERVE)) {
+               /* We honor MAP_NORESERVE if allowed to overcommit */
+               if (sysctl_overcommit_memory != OVERCOMMIT_NEVER)
+                       vm_flags |= VM_NORESERVE;
+
+               /* hugetlb applies strict overcommit unless MAP_NORESERVE */
+               if (file && is_file_hugepages(file))
+                       vm_flags |= VM_NORESERVE;
+       }
 
        /*
         * Private writable mapping: check memory availability
         */
-       if (accountable_mapping(vm_flags)) {
+       if (accountable_mapping(file, vm_flags)) {
                charged = len >> PAGE_SHIFT;
                if (security_vm_enough_memory(charged))
                        return -ENOMEM;