1 files changed, 44 insertions, 0 deletions

diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index 78d6a9e5830e..81b2750f3666 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -493,6 +493,14 @@ static int __init numa_register_memblks(struct numa_meminfo *mi)
 		struct numa_memblk *mb = &mi->blk[i];
 		memblock_set_node(mb->start, mb->end - mb->start,
 				  &memblock.memory, mb->nid);
+
+		/*
+		 * At this time, all memory regions reserved by memblock are
+		 * used by the kernel. Set the nid in memblock.reserved will
+		 * mark out all the nodes the kernel resides in.
+		 */
+		memblock_set_node(mb->start, mb->end - mb->start,
+				  &memblock.reserved, mb->nid);
 	}
 
 	/*
@@ -554,6 +562,30 @@ static void __init numa_init_array(void)
 	}
 }
 
+static void __init numa_clear_kernel_node_hotplug(void)
+{
+	int i, nid;
+	nodemask_t numa_kernel_nodes;
+	unsigned long start, end;
+	struct memblock_type *type = &memblock.reserved;
+
+	/* Mark all kernel nodes. */
+	for (i = 0; i < type->cnt; i++)
+		node_set(type->regions[i].nid, numa_kernel_nodes);
+
+	/* Clear MEMBLOCK_HOTPLUG flag for memory in kernel nodes. */
+	for (i = 0; i < numa_meminfo.nr_blks; i++) {
+		nid = numa_meminfo.blk[i].nid;
+		if (!node_isset(nid, numa_kernel_nodes))
+			continue;
+
+		start = numa_meminfo.blk[i].start;
+		end = numa_meminfo.blk[i].end;
+
+		memblock_clear_hotplug(start, end - start);
+	}
+}
+
 static int __init numa_init(int (*init_func)(void))
 {
 	int i;
@@ -568,6 +600,8 @@ static int __init numa_init(int (*init_func)(void))
 	memset(&numa_meminfo, 0, sizeof(numa_meminfo));
 	WARN_ON(memblock_set_node(0, ULLONG_MAX, &memblock.memory,
 				  MAX_NUMNODES));
+	WARN_ON(memblock_set_node(0, ULLONG_MAX, &memblock.reserved,
+				  MAX_NUMNODES));
 	/* In case that parsing SRAT failed. */
 	WARN_ON(memblock_clear_hotplug(0, ULLONG_MAX));
 	numa_reset_distance();
@@ -605,6 +639,16 @@ static int __init numa_init(int (*init_func)(void))
 			numa_clear_node(i);
 	}
 	numa_init_array();
+
+	/*
+	 * At very early time, the kernel have to use some memory such as
+	 * loading the kernel image. We cannot prevent this anyway. So any
+	 * node the kernel resides in should be un-hotpluggable.
+	 *
+	 * And when we come here, numa_init() won't fail.
+	 */
+	numa_clear_kernel_node_hotplug();
+
 	return 0;
 }