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authorAndrew Morton <akpm@linux-foundation.org>2016-05-19 17:12:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-19 19:12:14 -0700
commit1aa8aea535977f0e0b398f39d052e7befff81da6 (patch)
treeb62bccedaf7ff2763dfc3788557482d16eb1cb46 /mm/util.c
parent29f9cb53d25cd9916537b44b0af7f0b95a2e4438 (diff)
downloadop-kernel-dev-1aa8aea535977f0e0b398f39d052e7befff81da6.zip
op-kernel-dev-1aa8aea535977f0e0b398f39d052e7befff81da6.tar.gz
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>
Diffstat (limited to 'mm/util.c')
-rw-r--r--mm/util.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/mm/util.c b/mm/util.c
index 6cc81e7..8a1b3a1 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;
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