mm: uninline page_mapped()

It's huge.  Uninlining it saves 206 bytes per callsite.  Shaves 4924
bytes from the x86_64 allmodconfig vmlinux.

[akpm@linux-foundation.org: coding-style fixes]
Cc: Steve Capper <steve.capper@arm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/mm/util.c b/mm/util.c
index 6cc81e7b8705..8a1b3a1fb595 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -346,6 +346,29 @@ void *page_rmapping(struct page *page)
         return __page_rmapping(page);
 }
 
+/*
+ * Return true if this page is mapped into pagetables.
+ * For compound page it returns true if any subpage of compound page is mapped.
+ */
+bool page_mapped(struct page *page)
+{
+        int i;
+
+        if (likely(!PageCompound(page)))
+                return atomic_read(&page->_mapcount) >= 0;
+        page = compound_head(page);
+        if (atomic_read(compound_mapcount_ptr(page)) >= 0)
+                return true;
+        if (PageHuge(page))
+                return false;
+        for (i = 0; i < hpage_nr_pages(page); i++) {
+                if (atomic_read(&page[i]._mapcount) >= 0)
+                        return true;
+        }
+        return false;
+}
+EXPORT_SYMBOL(page_mapped);
+
 struct anon_vma *page_anon_vma(struct page *page)
 {
         unsigned long mapping;