x86_64: disable srat when numa emulation succeeds

When NUMA emulation succeeds, acpi_numa needs to be set to -1 so that
srat_disabled() will always return true.  We won't be calling
acpi_scan_nodes() or registering the true nodes we've found.

[[email protected]: Fix x86_64 CONFIG_NUMA_EMU build: acpi_numa needs CONFIG_ACPI_NUMA]
Signed-off-by: David Rientjes <[email protected]>
Cc: Len Brown <[email protected]>
Signed-off-by: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/arch/x86_64/mm/numa.c b/arch/x86_64/mm/numa.c
index 0191b1ca6aa477d3ebd284ba15ae58b314ca2eb3..6da235522269e856fc000807888db8e345891a90 100644 (file)
--- a/arch/x86_64/mm/numa.c
+++ b/arch/x86_64/mm/numa.c
@@ -473,9 +473,13 @@ out:
 
        /*
         * We need to vacate all active ranges that may have been registered by
-        * SRAT.
+        * SRAT and set acpi_numa to -1 so that srat_disabled() always returns
+        * true.  NUMA emulation has succeeded so we will not scan ACPI nodes.
         */
        remove_all_active_ranges();
+#ifdef CONFIG_ACPI_NUMA
+       acpi_numa = -1;
+#endif
        for_each_node_mask(i, node_possible_map) {
                e820_register_active_regions(i, nodes[i].start >> PAGE_SHIFT,
                                                nodes[i].end >> PAGE_SHIFT);