[PATCH] hugepages: fold find_or_alloc_pages into huge_no_page()

The number of parameters for find_or_alloc_page increases significantly after
policy support is added to huge pages.  Simplify the code by folding
find_or_alloc_huge_page() into hugetlb_no_page().

Adam Litke objected to this piece in an earlier patch but I think this is a
good simplification.  Diffstat shows that we can get rid of almost half of the
lines of find_or_alloc_page().  If we can find no consensus then lets simply
drop this patch.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@muc.de>
Acked-by: William Lee Irwin III <wli@holomorphy.com>
Cc: Adam Litke <agl@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index eb405565949da5bd2bee78df2ea2b6dbb478c64c..f4c43d7980ba2d83ff3d038995792aa93d991d18 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -368,43 +368,6 @@ void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
        flush_tlb_range(vma, start, end);
 }
 
-static struct page *find_or_alloc_huge_page(struct vm_area_struct *vma,
-                       unsigned long addr, struct address_space *mapping,
-                       unsigned long idx, int shared)
-{
-       struct page *page;
-       int err;
-
-retry:
-       page = find_lock_page(mapping, idx);
-       if (page)
-               goto out;
-
-       if (hugetlb_get_quota(mapping))
-               goto out;
-       page = alloc_huge_page(vma, addr);
-       if (!page) {
-               hugetlb_put_quota(mapping);
-               goto out;
-       }
-
-       if (shared) {
-               err = add_to_page_cache(page, mapping, idx, GFP_KERNEL);
-               if (err) {
-                       put_page(page);
-                       hugetlb_put_quota(mapping);
-                       if (err == -EEXIST)
-                               goto retry;
-                       page = NULL;
-               }
-       } else {
-               /* Caller expects a locked page */
-               lock_page(page);
-       }
-out:
-       return page;
-}
-
 static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
                        unsigned long address, pte_t *ptep, pte_t pte)
 {
@@ -471,12 +434,31 @@ int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
         * Use page lock to guard against racing truncation
         * before we get page_table_lock.
         */
-       page = find_or_alloc_huge_page(vma, address, mapping, idx,
-                       vma->vm_flags & VM_SHARED);
-       if (!page)
-               goto out;
+retry:
+       page = find_lock_page(mapping, idx);
+       if (!page) {
+               if (hugetlb_get_quota(mapping))
+                       goto out;
+               page = alloc_huge_page(vma, address);
+               if (!page) {
+                       hugetlb_put_quota(mapping);
+                       goto out;
+               }
 
-       BUG_ON(!PageLocked(page));
+               if (vma->vm_flags & VM_SHARED) {
+                       int err;
+
+                       err = add_to_page_cache(page, mapping, idx, GFP_KERNEL);
+                       if (err) {
+                               put_page(page);
+                               hugetlb_put_quota(mapping);
+                               if (err == -EEXIST)
+                                       goto retry;
+                               goto out;
+                       }
+               } else
+                       lock_page(page);
+       }
 
        spin_lock(&mm->page_table_lock);
        size = i_size_read(mapping->host) >> HPAGE_SHIFT;