x86: reduce memory and intra-node effects

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/apic_64.c

@@ -1175,14 +1175,15 @@ __cpuinit int apic_is_clustered_box(void)
 {
 	int i, clusters, zeros;
 	unsigned id;
+	u16 *bios_cpu_apicid = x86_bios_cpu_apicid_early_ptr;
 	DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
 
 	bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
 
 	for (i = 0; i < NR_CPUS; i++) {
 		/* are we being called early in kernel startup? */
-		if (x86_bios_cpu_apicid_early_ptr) {
-			id = ((u16 *)x86_bios_cpu_apicid_early_ptr)[i];
+		if (bios_cpu_apicid) {
+			id = bios_cpu_apicid[i];
 		}
 		else if (i < nr_cpu_ids) {
 			if (cpu_present(i))

arch/x86/kernel/mpparse_64.c

@@ -130,8 +130,8 @@ static void __cpuinit MP_processor_info(struct mpc_config_processor *m)
  	}
 	/* are we being called early in kernel startup? */
 	if (x86_cpu_to_apicid_early_ptr) {
-		u16 *cpu_to_apicid = (u16 *)x86_cpu_to_apicid_early_ptr;
-		u16 *bios_cpu_apicid = (u16 *)x86_bios_cpu_apicid_early_ptr;
+		u16 *cpu_to_apicid = x86_cpu_to_apicid_early_ptr;
+		u16 *bios_cpu_apicid = x86_bios_cpu_apicid_early_ptr;
 
 		cpu_to_apicid[cpu] = m->mpc_apicid;
 		bios_cpu_apicid[cpu] = m->mpc_apicid;

arch/x86/mm/numa_64.c

@@ -562,7 +562,7 @@ __cpuinit void numa_add_cpu(int cpu)
 
 void __cpuinit numa_set_node(int cpu, int node)
 {
-	u16 *cpu_to_node_map = (u16 *)x86_cpu_to_node_map_early_ptr;
+	u16 *cpu_to_node_map = x86_cpu_to_node_map_early_ptr;
 
 	cpu_pda(cpu)->nodenumber = node;
 

arch/x86/mm/srat_64.c

@@ -346,8 +346,12 @@ int __init acpi_scan_nodes(unsigned long start, unsigned long end)
 	/* First clean up the node list */
 	for (i = 0; i < MAX_NUMNODES; i++) {
 		cutoff_node(i, start, end);
-		/* ZZZ why was this needed. At least add a comment */
-		if (nodes[i].end && (nodes[i].end - nodes[i].start) < NODE_MIN_SIZE) {
+		/*
+		 * don't confuse VM with a node that doesn't have the
+		 * minimum memory.
+		 */
+		if (nodes[i].end &&
+			(nodes[i].end - nodes[i].start) < NODE_MIN_SIZE) {
 			unparse_node(i);
 			node_set_offline(i);
 		}

include/asm-x86/topology.h

@@ -40,7 +40,7 @@ extern cpumask_t node_to_cpumask_map[];
 /* Returns the number of the node containing CPU 'cpu' */
 static inline int cpu_to_node(int cpu)
 {
-	u16 *cpu_to_node_map = (u16 *)x86_cpu_to_node_map_early_ptr;
+	u16 *cpu_to_node_map = x86_cpu_to_node_map_early_ptr;
 
 	if (cpu_to_node_map)
 		return cpu_to_node_map[cpu];