[Devel] [PATCH rh7 3/7] Move PageBalloon and PageBuddy helpers to page-flags.h

Vladimir Davydov vdavydov at virtuozzo.com
Mon May 30 07:23:19 PDT 2016


I want to add one more flag based on page->_mapcount, which will be used
in memcontrol.h. We'd better not include mm.h, where other such flags
are defined, to memcontrol.h to avoid possible circular dependencies,
so let's move their definitions to page-flags.h.

Note, upstream these flags are defined in page-flags.h, but I don't want
to pull the commit moving them there due to conflicts.

Signed-off-by: Vladimir Davydov <vdavydov at virtuozzo.com>
---
 include/linux/mm.h         | 47 ----------------------------------------------
 include/linux/page-flags.h | 47 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+), 47 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 582c6db1f08e..a282ed2d1bdd 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -508,53 +508,6 @@ static inline void init_page_count(struct page *page)
 	atomic_set(&page->_count, 1);
 }
 
-/*
- * PageBuddy() indicate that the page is free and in the buddy system
- * (see mm/page_alloc.c).
- *
- * PAGE_BUDDY_MAPCOUNT_VALUE must be <= -2 but better not too close to
- * -2 so that an underflow of the page_mapcount() won't be mistaken
- * for a genuine PAGE_BUDDY_MAPCOUNT_VALUE. -128 can be created very
- * efficiently by most CPU architectures.
- */
-#define PAGE_BUDDY_MAPCOUNT_VALUE (-128)
-
-static inline int PageBuddy(struct page *page)
-{
-	return atomic_read(&page->_mapcount) == PAGE_BUDDY_MAPCOUNT_VALUE;
-}
-
-static inline void __SetPageBuddy(struct page *page)
-{
-	VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page);
-	atomic_set(&page->_mapcount, PAGE_BUDDY_MAPCOUNT_VALUE);
-}
-
-static inline void __ClearPageBuddy(struct page *page)
-{
-	VM_BUG_ON_PAGE(!PageBuddy(page), page);
-	atomic_set(&page->_mapcount, -1);
-}
-
-#define PAGE_BALLOON_MAPCOUNT_VALUE (-256)
-
-static inline int PageBalloon(struct page *page)
-{
-	return atomic_read(&page->_mapcount) == PAGE_BALLOON_MAPCOUNT_VALUE;
-}
-
-static inline void __SetPageBalloon(struct page *page)
-{
-	VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page);
-	atomic_set(&page->_mapcount, PAGE_BALLOON_MAPCOUNT_VALUE);
-}
-
-static inline void __ClearPageBalloon(struct page *page)
-{
-	VM_BUG_ON_PAGE(!PageBalloon(page), page);
-	atomic_set(&page->_mapcount, -1);
-}
-
 void put_page(struct page *page);
 void put_pages_list(struct list_head *pages);
 
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 28f5c4ac98fc..cdf83ecac8f3 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -477,6 +477,53 @@ static inline int PageTransTail(struct page *page)
 #endif
 
 /*
+ * PageBuddy() indicate that the page is free and in the buddy system
+ * (see mm/page_alloc.c).
+ *
+ * PAGE_BUDDY_MAPCOUNT_VALUE must be <= -2 but better not too close to
+ * -2 so that an underflow of the page_mapcount() won't be mistaken
+ * for a genuine PAGE_BUDDY_MAPCOUNT_VALUE. -128 can be created very
+ * efficiently by most CPU architectures.
+ */
+#define PAGE_BUDDY_MAPCOUNT_VALUE (-128)
+
+static inline int PageBuddy(struct page *page)
+{
+	return atomic_read(&page->_mapcount) == PAGE_BUDDY_MAPCOUNT_VALUE;
+}
+
+static inline void __SetPageBuddy(struct page *page)
+{
+	VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page);
+	atomic_set(&page->_mapcount, PAGE_BUDDY_MAPCOUNT_VALUE);
+}
+
+static inline void __ClearPageBuddy(struct page *page)
+{
+	VM_BUG_ON_PAGE(!PageBuddy(page), page);
+	atomic_set(&page->_mapcount, -1);
+}
+
+#define PAGE_BALLOON_MAPCOUNT_VALUE (-256)
+
+static inline int PageBalloon(struct page *page)
+{
+	return atomic_read(&page->_mapcount) == PAGE_BALLOON_MAPCOUNT_VALUE;
+}
+
+static inline void __SetPageBalloon(struct page *page)
+{
+	VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page);
+	atomic_set(&page->_mapcount, PAGE_BALLOON_MAPCOUNT_VALUE);
+}
+
+static inline void __ClearPageBalloon(struct page *page)
+{
+	VM_BUG_ON_PAGE(!PageBalloon(page), page);
+	atomic_set(&page->_mapcount, -1);
+}
+
+/*
  * If network-based swap is enabled, sl*b must keep track of whether pages
  * were allocated from pfmemalloc reserves.
  */
-- 
2.1.4



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