mm: move enum vm_event_item into a standalone header file

enums are problematic because they cannot be forward-declared:

  akpm2:/home/akpm> cat t.c

  enum foo;

  static inline void bar(enum foo f)
  {
  }
  akpm2:/home/akpm> gcc -c t.c
  t.c:4: error: parameter 1 ('f') has incomplete type

So move the enum's definition into a standalone header file which can be used
wherever its definition is needed.

Cc: Ying Han <yinghan@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 65 insertions, 61 deletions

diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
new file mode 100644
index 000000000000..03b90cdc1921
--- /dev/null
+++ b/include/linux/vm_event_item.h
@@ -0,0 +1,64 @@
+#ifndef VM_EVENT_ITEM_H_INCLUDED
+#define VM_EVENT_ITEM_H_INCLUDED
+
+#ifdef CONFIG_ZONE_DMA
+#define DMA_ZONE(xx) xx##_DMA,
+#else
+#define DMA_ZONE(xx)
+#endif
+
+#ifdef CONFIG_ZONE_DMA32
+#define DMA32_ZONE(xx) xx##_DMA32,
+#else
+#define DMA32_ZONE(xx)
+#endif
+
+#ifdef CONFIG_HIGHMEM
+#define HIGHMEM_ZONE(xx) , xx##_HIGH
+#else
+#define HIGHMEM_ZONE(xx)
+#endif
+
+#define FOR_ALL_ZONES(xx) DMA_ZONE(xx) DMA32_ZONE(xx) xx##_NORMAL HIGHMEM_ZONE(xx) , xx##_MOVABLE
+
+enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
+                FOR_ALL_ZONES(PGALLOC),
+                PGFREE, PGACTIVATE, PGDEACTIVATE,
+                PGFAULT, PGMAJFAULT,
+                FOR_ALL_ZONES(PGREFILL),
+                FOR_ALL_ZONES(PGSTEAL),
+                FOR_ALL_ZONES(PGSCAN_KSWAPD),
+                FOR_ALL_ZONES(PGSCAN_DIRECT),
+#ifdef CONFIG_NUMA
+                PGSCAN_ZONE_RECLAIM_FAILED,
+#endif
+                PGINODESTEAL, SLABS_SCANNED, KSWAPD_STEAL, KSWAPD_INODESTEAL,
+                KSWAPD_LOW_WMARK_HIT_QUICKLY, KSWAPD_HIGH_WMARK_HIT_QUICKLY,
+                KSWAPD_SKIP_CONGESTION_WAIT,
+                PAGEOUTRUN, ALLOCSTALL, PGROTATED,
+#ifdef CONFIG_COMPACTION
+                COMPACTBLOCKS, COMPACTPAGES, COMPACTPAGEFAILED,
+                COMPACTSTALL, COMPACTFAIL, COMPACTSUCCESS,
+#endif
+#ifdef CONFIG_HUGETLB_PAGE
+                HTLB_BUDDY_PGALLOC, HTLB_BUDDY_PGALLOC_FAIL,
+#endif
+                UNEVICTABLE_PGCULLED,   /* culled to noreclaim list */
+                UNEVICTABLE_PGSCANNED,  /* scanned for reclaimability */
+                UNEVICTABLE_PGRESCUED,  /* rescued from noreclaim list */
+                UNEVICTABLE_PGMLOCKED,
+                UNEVICTABLE_PGMUNLOCKED,
+                UNEVICTABLE_PGCLEARED,  /* on COW, page truncate */
+                UNEVICTABLE_PGSTRANDED, /* unable to isolate on unlock */
+                UNEVICTABLE_MLOCKFREED,
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+                THP_FAULT_ALLOC,
+                THP_FAULT_FALLBACK,
+                THP_COLLAPSE_ALLOC,
+                THP_COLLAPSE_ALLOC_FAILED,
+                THP_SPLIT,
+#endif
+                NR_VM_EVENT_ITEMS
+};
+
+#endif          /* VM_EVENT_ITEM_H_INCLUDED */
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 51359837511a..bcd942fa611c 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -5,69 +5,9 @@
 #include <linux/percpu.h>
 #include <linux/mm.h>
 #include <linux/mmzone.h>
+#include <linux/vm_event_item.h>
 #include <asm/atomic.h>
 
-#ifdef CONFIG_ZONE_DMA
-#define DMA_ZONE(xx) xx##_DMA,
-#else
-#define DMA_ZONE(xx)
-#endif
-
-#ifdef CONFIG_ZONE_DMA32
-#define DMA32_ZONE(xx) xx##_DMA32,
-#else
-#define DMA32_ZONE(xx)
-#endif
-
-#ifdef CONFIG_HIGHMEM
-#define HIGHMEM_ZONE(xx) , xx##_HIGH
-#else
-#define HIGHMEM_ZONE(xx)
-#endif
-
-
-#define FOR_ALL_ZONES(xx) DMA_ZONE(xx) DMA32_ZONE(xx) xx##_NORMAL HIGHMEM_ZONE(xx) , xx##_MOVABLE
-
-enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
-                FOR_ALL_ZONES(PGALLOC),
-                PGFREE, PGACTIVATE, PGDEACTIVATE,
-                PGFAULT, PGMAJFAULT,
-                FOR_ALL_ZONES(PGREFILL),
-                FOR_ALL_ZONES(PGSTEAL),
-                FOR_ALL_ZONES(PGSCAN_KSWAPD),
-                FOR_ALL_ZONES(PGSCAN_DIRECT),
-#ifdef CONFIG_NUMA
-                PGSCAN_ZONE_RECLAIM_FAILED,
-#endif
-                PGINODESTEAL, SLABS_SCANNED, KSWAPD_STEAL, KSWAPD_INODESTEAL,
-                KSWAPD_LOW_WMARK_HIT_QUICKLY, KSWAPD_HIGH_WMARK_HIT_QUICKLY,
-                KSWAPD_SKIP_CONGESTION_WAIT,
-                PAGEOUTRUN, ALLOCSTALL, PGROTATED,
-#ifdef CONFIG_COMPACTION
-                COMPACTBLOCKS, COMPACTPAGES, COMPACTPAGEFAILED,
-                COMPACTSTALL, COMPACTFAIL, COMPACTSUCCESS,
-#endif
-#ifdef CONFIG_HUGETLB_PAGE
-                HTLB_BUDDY_PGALLOC, HTLB_BUDDY_PGALLOC_FAIL,
-#endif
-                UNEVICTABLE_PGCULLED,   /* culled to noreclaim list */
-                UNEVICTABLE_PGSCANNED,  /* scanned for reclaimability */
-                UNEVICTABLE_PGRESCUED,  /* rescued from noreclaim list */
-                UNEVICTABLE_PGMLOCKED,
-                UNEVICTABLE_PGMUNLOCKED,
-                UNEVICTABLE_PGCLEARED,  /* on COW, page truncate */
-                UNEVICTABLE_PGSTRANDED, /* unable to isolate on unlock */
-                UNEVICTABLE_MLOCKFREED,
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-                THP_FAULT_ALLOC,
-                THP_FAULT_FALLBACK,
-                THP_COLLAPSE_ALLOC,
-                THP_COLLAPSE_ALLOC_FAILED,
-                THP_SPLIT,
-#endif
-                NR_VM_EVENT_ITEMS
-};
-
 extern int sysctl_stat_interval;
 
 #ifdef CONFIG_VM_EVENT_COUNTERS