smaps: break out smaps_pte_entry() from smaps_pte_range()

We will use smaps_pte_entry() in a moment to handle both small and
transparent large pages.  But, we must break it out of smaps_pte_range()
first.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Eric B Munson <emunson@mgebm.net>
Tested-by: Eric B Munson <emunson@mgebm.net>
Cc: Michael J Wolf <mjwolf@us.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 47 insertions, 40 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 78fd3621f565..5cd06fa3106b 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -333,56 +333,63 @@ struct mem_size_stats {
         u64 pss;
 };
 
-static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
-                           struct mm_walk *walk)
+
+static void smaps_pte_entry(pte_t ptent, unsigned long addr,
+                struct mm_walk *walk)
 {
         struct mem_size_stats *mss = walk->private;
         struct vm_area_struct *vma = mss->vma;
-        pte_t *pte, ptent;
-        spinlock_t *ptl;
         struct page *page;
         int mapcount;
 
-        split_huge_page_pmd(walk->mm, pmd);
-
-        pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
-        for (; addr != end; pte++, addr += PAGE_SIZE) {
-                ptent = *pte;
+        if (is_swap_pte(ptent)) {
+                mss->swap += PAGE_SIZE;
+                return;
+        }
 
-                if (is_swap_pte(ptent)) {
-                        mss->swap += PAGE_SIZE;
-                        continue;
-                }
+        if (!pte_present(ptent))
+                return;
+
+        page = vm_normal_page(vma, addr, ptent);
+        if (!page)
+                return;
+
+        if (PageAnon(page))
+                mss->anonymous += PAGE_SIZE;
+
+        mss->resident += PAGE_SIZE;
+        /* Accumulate the size in pages that have been accessed. */
+        if (pte_young(ptent) || PageReferenced(page))
+                mss->referenced += PAGE_SIZE;
+        mapcount = page_mapcount(page);
+        if (mapcount >= 2) {
+                if (pte_dirty(ptent) || PageDirty(page))
+                        mss->shared_dirty += PAGE_SIZE;
+                else
+                        mss->shared_clean += PAGE_SIZE;
+                mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
+        } else {
+                if (pte_dirty(ptent) || PageDirty(page))
+                        mss->private_dirty += PAGE_SIZE;
+                else
+                        mss->private_clean += PAGE_SIZE;
+                mss->pss += (PAGE_SIZE << PSS_SHIFT);
+        }
+}
 
-                if (!pte_present(ptent))
-                        continue;
+static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
+                           struct mm_walk *walk)
+{
+        struct mem_size_stats *mss = walk->private;
+        struct vm_area_struct *vma = mss->vma;
+        pte_t *pte;
+        spinlock_t *ptl;
 
-                page = vm_normal_page(vma, addr, ptent);
-                if (!page)
-                        continue;
+        split_huge_page_pmd(walk->mm, pmd);
 
-                if (PageAnon(page))
-                        mss->anonymous += PAGE_SIZE;
-
-                mss->resident += PAGE_SIZE;
-                /* Accumulate the size in pages that have been accessed. */
-                if (pte_young(ptent) || PageReferenced(page))
-                        mss->referenced += PAGE_SIZE;
-                mapcount = page_mapcount(page);
-                if (mapcount >= 2) {
-                        if (pte_dirty(ptent) || PageDirty(page))
-                                mss->shared_dirty += PAGE_SIZE;
-                        else
-                                mss->shared_clean += PAGE_SIZE;
-                        mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
-                } else {
-                        if (pte_dirty(ptent) || PageDirty(page))
-                                mss->private_dirty += PAGE_SIZE;
-                        else
-                                mss->private_clean += PAGE_SIZE;
-                        mss->pss += (PAGE_SIZE << PSS_SHIFT);
-                }
-        }
+        pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+        for (; addr != end; pte++, addr += PAGE_SIZE)
+                smaps_pte_entry(*pte, addr, walk);
         pte_unmap_unlock(pte - 1, ptl);
         cond_resched();
         return 0;