mm: use vm_unmapped_area() in hugetlbfs on sparc64 architecture

Update the sparc64 hugetlb_get_unmapped_area function to make use of
vm_unmapped_area() instead of implementing a brute force search.

Signed-off-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c
index f76f83d..d2b5944 100644 (file)
--- a/arch/sparc/mm/hugetlbpage.c
+++ b/arch/sparc/mm/hugetlbpage.c
@@ -30,55 +30,28 @@ static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *filp,
                                                        unsigned long pgoff,
                                                        unsigned long flags)
 {
-       struct mm_struct *mm = current->mm;
-       struct vm_area_struct * vma;
        unsigned long task_size = TASK_SIZE;
-       unsigned long start_addr;
+       struct vm_unmapped_area_info info;
 
        if (test_thread_flag(TIF_32BIT))
                task_size = STACK_TOP32;
-       if (unlikely(len >= VA_EXCLUDE_START))
-               return -ENOMEM;
 
-       if (len > mm->cached_hole_size) {
-               start_addr = addr = mm->free_area_cache;
-       } else {
-               start_addr = addr = TASK_UNMAPPED_BASE;
-               mm->cached_hole_size = 0;
+       info.flags = 0;
+       info.length = len;
+       info.low_limit = TASK_UNMAPPED_BASE;
+       info.high_limit = min(task_size, VA_EXCLUDE_START);
+       info.align_mask = PAGE_MASK & ~HPAGE_MASK;
+       info.align_offset = 0;
+       addr = vm_unmapped_area(&info);
+
+       if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) {
+               VM_BUG_ON(addr != -ENOMEM);
+               info.low_limit = VA_EXCLUDE_END;
+               info.high_limit = task_size;
+               addr = vm_unmapped_area(&info);
        }
 
-       task_size -= len;
-
-full_search:
-       addr = ALIGN(addr, HPAGE_SIZE);
-
-       for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
-               /* At this point:  (!vma || addr < vma->vm_end). */
-               if (addr < VA_EXCLUDE_START &&
-                   (addr + len) >= VA_EXCLUDE_START) {
-                       addr = VA_EXCLUDE_END;
-                       vma = find_vma(mm, VA_EXCLUDE_END);
-               }
-               if (unlikely(task_size < addr)) {
-                       if (start_addr != TASK_UNMAPPED_BASE) {
-                               start_addr = addr = TASK_UNMAPPED_BASE;
-                               mm->cached_hole_size = 0;
-                               goto full_search;
-                       }
-                       return -ENOMEM;
-               }
-               if (likely(!vma || addr + len <= vma->vm_start)) {
-                       /*
-                        * Remember the place where we stopped the search:
-                        */
-                       mm->free_area_cache = addr + len;
-                       return addr;
-               }
-               if (addr + mm->cached_hole_size < vma->vm_start)
-                       mm->cached_hole_size = vma->vm_start - addr;
-
-               addr = ALIGN(vma->vm_end, HPAGE_SIZE);
-       }
+       return addr;
 }
 
 static unsigned long
@@ -87,71 +60,34 @@ hugetlb_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
                                  const unsigned long pgoff,
                                  const unsigned long flags)
 {
-       struct vm_area_struct *vma;
        struct mm_struct *mm = current->mm;
        unsigned long addr = addr0;
+       struct vm_unmapped_area_info info;
 
        /* This should only ever run for 32-bit processes.  */
        BUG_ON(!test_thread_flag(TIF_32BIT));
 
-       /* check if free_area_cache is useful for us */
-       if (len <= mm->cached_hole_size) {
-               mm->cached_hole_size = 0;
-               mm->free_area_cache = mm->mmap_base;
-       }
-
-       /* either no address requested or can't fit in requested address hole */
-       addr = mm->free_area_cache & HPAGE_MASK;
-
-       /* make sure it can fit in the remaining address space */
-       if (likely(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 (unlikely(mm->mmap_base < len))
-               goto bottomup;
-
-       addr = (mm->mmap_base-len) & HPAGE_MASK;
-
-       do {
-               /*
-                * Lookup failure means no vma is above this address,
-                * else if new region fits below vma->vm_start,
-                * return with success:
-                */
-               vma = find_vma(mm, addr);
-               if (likely(!vma || addr+len <= vma->vm_start)) {
-                       /* remember the address as a hint for next time */
-                       return (mm->free_area_cache = addr);
-               }
-
-               /* remember the largest hole we saw so far */
-               if (addr + mm->cached_hole_size < vma->vm_start)
-                       mm->cached_hole_size = vma->vm_start - addr;
-
-               /* try just below the current vma->vm_start */
-               addr = (vma->vm_start-len) & HPAGE_MASK;
-       } while (likely(len < vma->vm_start));
+       info.flags = VM_UNMAPPED_AREA_TOPDOWN;
+       info.length = len;
+       info.low_limit = PAGE_SIZE;
+       info.high_limit = mm->mmap_base;
+       info.align_mask = PAGE_MASK & ~HPAGE_MASK;
+       info.align_offset = 0;
+       addr = vm_unmapped_area(&info);
 
-bottomup:
        /*
         * A failed mmap() very likely causes application failure,
         * so fall back to the bottom-up function here. This scenario
         * can happen with large stack limits and large mmap()
         * allocations.
         */
-       mm->cached_hole_size = ~0UL;
-       mm->free_area_cache = TASK_UNMAPPED_BASE;
-       addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
-       /*
-        * Restore the topdown base:
-        */
-       mm->free_area_cache = mm->mmap_base;
-       mm->cached_hole_size = ~0UL;
+       if (addr & ~PAGE_MASK) {
+               VM_BUG_ON(addr != -ENOMEM);
+               info.flags = 0;
+               info.low_limit = TASK_UNMAPPED_BASE;
+               info.high_limit = STACK_TOP32;
+               addr = vm_unmapped_area(&info);
+       }
 
        return addr;
 }