x86-64, NUMA: Simplify hotplug node handling in acpi_numa_memory_affinity_init()

Hotplug node handling in acpi_numa_memory_affinity_init() was
unnecessarily complicated with storing the original nodes[] entry and
restoring it afterwards.  Simplify it by not modifying the nodes[]
entry for hotplug nodes from the beginning.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Shaohui Zheng <shaohui.zheng@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 13 insertions, 18 deletions

diff --git a/arch/x86/mm/srat_64.c b/arch/x86/mm/srat_64.c
index 23498f8b09a..988b0b70ff3 100644
--- a/arch/x86/mm/srat_64.c
+++ b/arch/x86/mm/srat_64.c
@@ -251,7 +251,7 @@ update_nodes_add(int node, unsigned long start, unsigned long end)
 void __init
 acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
 {
-        struct bootnode *nd, oldnode;
+        struct bootnode *nd;
         unsigned long start, end;
         int node, pxm;
         int i;
@@ -289,28 +289,23 @@ acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
                 bad_srat();
                 return;
         }
-        nd = &nodes[node];
-        oldnode = *nd;
-        if (!node_test_and_set(node, nodes_parsed)) {
-                nd->start = start;
-                nd->end = end;
-        } else {
-                if (start < nd->start)
-                        nd->start = start;
-                if (nd->end < end)
-                        nd->end = end;
-        }
 
         printk(KERN_INFO "SRAT: Node %u PXM %u %lx-%lx\n", node, pxm,
                start, end);
 
-        if (ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE) {
+        if (!(ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE)) {
+                nd = &nodes[node];
+                if (!node_test_and_set(node, nodes_parsed)) {
+                        nd->start = start;
+                        nd->end = end;
+                } else {
+                        if (start < nd->start)
+                                nd->start = start;
+                        if (nd->end < end)
+                                nd->end = end;
+                }
+        } else
                 update_nodes_add(node, start, end);
-                /* restore nodes[node] */
-                *nd = oldnode;
-                if ((nd->start | nd->end) == 0)
-                        node_clear(node, nodes_parsed);
-        }
 
         node_memblk_range[num_node_memblks].start = start;
         node_memblk_range[num_node_memblks].end = end;