From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Date: Wed, 18 Feb 2009 22:48:33 +0000 (-0800)
Subject: mm: fix memmap init for handling memory hole
X-Git-Tag: v2.6.29-rc6~50
X-Git-Url: http://bbs.cooldavid.org/git/?a=commitdiff_plain;h=cc2559bccc72767cb446f79b071d96c30c26439b;p=net-next-2.6.git

mm: fix memmap init for handling memory hole

Now, early_pfn_in_nid(PFN, NID) may returns false if PFN is a hole.
and memmap initialization was not done. This was a trouble for
sparc boot.

To fix this, the PFN should be initialized and marked as PG_reserved.
This patch changes early_pfn_in_nid() return true if PFN is a hole.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reported-by: David Miller <davem@davemlloft.net>
Tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/arch/ia64/mm/numa.c b/arch/ia64/mm/numa.c
index 5061c3fb679..3efea7d0a35 100644
--- a/arch/ia64/mm/numa.c
+++ b/arch/ia64/mm/numa.c
@@ -70,7 +70,7 @@ int __meminit __early_pfn_to_nid(unsigned long pfn)
 			return node_memblk[i].nid;
 	}
 
-	return 0;
+	return -1;
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 09c14e213b6..1aca6cebbb7 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -1071,7 +1071,7 @@ void sparse_init(void);
 #endif /* CONFIG_SPARSEMEM */
 
 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
-#define early_pfn_in_nid(pfn, nid)	(early_pfn_to_nid(pfn) == (nid))
+bool early_pfn_in_nid(unsigned long pfn, int nid);
 #else
 #define early_pfn_in_nid(pfn, nid)	(1)
 #endif
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c5dd74602ef..5c44ed49ca9 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3000,16 +3000,33 @@ int __meminit __early_pfn_to_nid(unsigned long pfn)
 		if (start_pfn <= pfn && pfn < end_pfn)
 			return early_node_map[i].nid;
 	}
-
-	return 0;
+	/* This is a memory hole */
+	return -1;
 }
 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
 
 int __meminit early_pfn_to_nid(unsigned long pfn)
 {
-	return __early_pfn_to_nid(pfn);
+	int nid;
+
+	nid = __early_pfn_to_nid(pfn);
+	if (nid >= 0)
+		return nid;
+	/* just returns 0 */
+	return 0;
 }
 
+#ifdef CONFIG_NODES_SPAN_OTHER_NODES
+bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
+{
+	int nid;
+
+	nid = __early_pfn_to_nid(pfn);
+	if (nid >= 0 && nid != node)
+		return false;
+	return true;
+}
+#endif
 
 /* Basic iterator support to walk early_node_map[] */
 #define for_each_active_range_index_in_nid(i, nid) \