mm: move swp_entry_t definition to include/linux/mm_types.h

swp_entry_t being defined in include/linux/swap.h instead of
include/linux/mm_types.h causes cyclic include dependency later when
include/linux/page_cgroup.h is included from writeback path.  Move the
definition to include/linux/mm_types.h.

While at it, reformat the comment above it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index bf9f575..fc2daff 100644 (file)
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -534,4 +534,12 @@ enum tlb_flush_reason {
        NR_TLB_FLUSH_REASONS,
 };
 
+ /*
+  * A swap entry has to fit into a "unsigned long", as the entry is hidden
+  * in the "index" field of the swapper address space.
+  */
+typedef struct {
+       unsigned long val;
+} swp_entry_t;
+
 #endif /* _LINUX_MM_TYPES_H */

diff --cc include/linux/swap.h
Simple merge