---

yaml
---
r: 109339
b: refs/heads/master
c: e80d6a2
h: refs/heads/master
i:
  109337: ed52519
  109335: 19b96e3
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: f1bcf7e3e734ea8713e08fbc3409f8bf26ec418f
+refs/heads/master: e80d6a248298721e0ec2cac150c539d8378577d8

trunk/arch/arm/Kconfig

@@ -810,6 +810,11 @@ config OABI_COMPAT
 	  UNPREDICTABLE (in fact it can be predicted that it won't work
 	  at all). If in doubt say Y.
 
+config ARCH_FLATMEM_HAS_HOLES
+	bool
+	default y
+	depends on FLATMEM
+
 config ARCH_DISCONTIGMEM_ENABLE
 	bool
 	default (ARCH_LH7A40X && !LH7A40X_CONTIGMEM)

trunk/mm/vmstat.c

@@ -516,9 +516,26 @@ static void pagetypeinfo_showblockcount_print(struct seq_file *m,
 			continue;
 
 		page = pfn_to_page(pfn);
+#ifdef CONFIG_ARCH_FLATMEM_HAS_HOLES
+		/*
+		 * Ordinarily, memory holes in flatmem still have a valid
+		 * memmap for the PFN range. However, an architecture for
+		 * embedded systems (e.g. ARM) can free up the memmap backing
+		 * holes to save memory on the assumption the memmap is
+		 * never used. The page_zone linkages are then broken even
+		 * though pfn_valid() returns true. Skip the page if the
+		 * linkages are broken. Even if this test passed, the impact
+		 * is that the counters for the movable type are off but
+		 * fragmentation monitoring is likely meaningless on small
+		 * systems.
+		 */
+		if (page_zone(page) != zone)
+			continue;
+#endif
 		mtype = get_pageblock_migratetype(page);
 
-		count[mtype]++;
+		if (mtype < MIGRATE_TYPES)
+			count[mtype]++;
 	}
 
 	/* Print counts */