mm: fold mlocked_vma_newpage() into its only call site

In previous commit(mm: use the light version __mod_zone_page_state in
mlocked_vma_newpage()) a irq-unsafe __mod_zone_page_state is used.  And as
suggested by Andrew, to reduce the risks that new call sites incorrectly
using mlocked_vma_newpage() without knowing they are adding racing, this
patch folds mlocked_vma_newpage() into its only call site,
page_add_new_anon_rmap, to make it open-cocded for people to know what is
going on.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jianyu Zhan <nasa4836@gmail.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Suggested-by: Hugh Dickins <hughd@google.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 17 insertions, 32 deletions

diff --git a/mm/internal.h b/mm/internal.h
index e067984bafa0..802c3a4fc03a 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -189,31 +189,6 @@ static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
 }
 
 /*
- * Called only in fault path, to determine if a new page is being
- * mapped into a LOCKED vma.  If it is, mark page as mlocked.
- */
-static inline int mlocked_vma_newpage(struct vm_area_struct *vma,
-                                    struct page *page)
-{
-        VM_BUG_ON_PAGE(PageLRU(page), page);
-
-        if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
-                return 0;
-
-        if (!TestSetPageMlocked(page)) {
-                /*
-                 * We use the irq-unsafe __mod_zone_page_stat because this
-                 * counter is not modified from interrupt context, and the pte
-                 * lock is held(spinlock), which implies preemption disabled.
-                 */
-                __mod_zone_page_state(page_zone(page), NR_MLOCK,
-                                    hpage_nr_pages(page));
-                count_vm_event(UNEVICTABLE_PGMLOCKED);
-        }
-        return 1;
-}
-
-/*
  * must be called with vma's mmap_sem held for read or write, and page locked.
  */
 extern void mlock_vma_page(struct page *page);
@@ -255,10 +230,6 @@ extern unsigned long vma_address(struct page *page,
                                  struct vm_area_struct *vma);
 #endif
 #else /* !CONFIG_MMU */
-static inline int mlocked_vma_newpage(struct vm_area_struct *v, struct page *p)
-{
-        return 0;
-}
 static inline void clear_page_mlock(struct page *page) { }
 static inline void mlock_vma_page(struct page *page) { }
 static inline void mlock_migrate_page(struct page *new, struct page *old) { }
diff --git a/mm/rmap.c b/mm/rmap.c
index 4644e10248f0..e375ce4bd93e 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1032,11 +1032,25 @@ void page_add_new_anon_rmap(struct page *page,
         __mod_zone_page_state(page_zone(page), NR_ANON_PAGES,
                         hpage_nr_pages(page));
         __page_set_anon_rmap(page, vma, address, 1);
-        if (!mlocked_vma_newpage(vma, page)) {
+
+        VM_BUG_ON_PAGE(PageLRU(page), page);
+        if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED)) {
                 SetPageActive(page);
                 lru_cache_add(page);
-        } else
-                add_page_to_unevictable_list(page);
+                return;
+        }
+
+        if (!TestSetPageMlocked(page)) {
+                /*
+                 * We use the irq-unsafe __mod_zone_page_stat because this
+                 * counter is not modified from interrupt context, and the pte
+                 * lock is held(spinlock), which implies preemption disabled.
+                 */
+                __mod_zone_page_state(page_zone(page), NR_MLOCK,
+                                    hpage_nr_pages(page));
+                count_vm_event(UNEVICTABLE_PGMLOCKED);
+        }
+        add_page_to_unevictable_list(page);
 }
 
 /**