[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>

1 files changed, 24 insertions, 42 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index eb405565949d..f4c43d7980ba 100644
--- 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;