[IA64] Minimize per_cpu reservations.

This attached patch significantly shrinks boot memory allocation on ia64.
It does this by not allocating per_cpu areas for cpus that can never
exist.

In the case where acpi does not have any numa node description of the
cpus, I defaulted to assigning the first 32 round-robin on the known
nodes..  For the !CONFIG_ACPI  I used for_each_possible_cpu().

Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

2 files changed, 35 insertions, 0 deletions

diff --git a/include/asm-ia64/acpi.h b/include/asm-ia64/acpi.h
index cd1cc39..fcfad32 100644
--- a/include/asm-ia64/acpi.h
+++ b/include/asm-ia64/acpi.h
@@ -35,6 +35,7 @@
 #include <linux/init.h>
 #include <linux/numa.h>
 #include <asm/system.h>
+#include <asm/numa.h>
 
 #define COMPILER_DEPENDENT_INT64	long
 #define COMPILER_DEPENDENT_UINT64	unsigned long
@@ -115,7 +116,11 @@ extern unsigned int is_cpu_cpei_target(unsigned int cpu);
 extern void set_cpei_target_cpu(unsigned int cpu);
 extern unsigned int get_cpei_target_cpu(void);
 extern void prefill_possible_map(void);
+#ifdef CONFIG_ACPI_HOTPLUG_CPU
 extern int additional_cpus;
+#else
+#define additional_cpus 0
+#endif
 
 #ifdef CONFIG_ACPI_NUMA
 #if MAX_NUMNODES > 256
@@ -129,6 +134,34 @@ extern int __initdata nid_to_pxm_map[MAX_NUMNODES];
 
 #define acpi_unlazy_tlb(x)
 
+#ifdef CONFIG_ACPI_NUMA
+extern cpumask_t early_cpu_possible_map;
+#define for_each_possible_early_cpu(cpu)  \
+	for_each_cpu_mask((cpu), early_cpu_possible_map)
+
+static inline void per_cpu_scan_finalize(int min_cpus, int reserve_cpus)
+{
+	int low_cpu, high_cpu;
+	int cpu;
+	int next_nid = 0;
+
+	low_cpu = cpus_weight(early_cpu_possible_map);
+
+	high_cpu = max(low_cpu, min_cpus);
+	high_cpu = min(high_cpu + reserve_cpus, NR_CPUS);
+
+	for (cpu = low_cpu; cpu < high_cpu; cpu++) {
+		cpu_set(cpu, early_cpu_possible_map);
+		if (node_cpuid[cpu].nid == NUMA_NO_NODE) {
+			node_cpuid[cpu].nid = next_nid;
+			next_nid++;
+			if (next_nid >= num_online_nodes())
+				next_nid = 0;
+		}
+	}
+}
+#endif /* CONFIG_ACPI_NUMA */
+
 #endif /*__KERNEL__*/
 
 #endif /*_ASM_ACPI_H*/
diff --git a/include/asm-ia64/numa.h b/include/asm-ia64/numa.h
index 6a8a27c..3499ff5 100644
--- a/include/asm-ia64/numa.h
+++ b/include/asm-ia64/numa.h
@@ -22,6 +22,8 @@
 
 #include <asm/mmzone.h>
 
+#define NUMA_NO_NODE	-1
+
 extern u16 cpu_to_node_map[NR_CPUS] __cacheline_aligned;
 extern cpumask_t node_to_cpu_mask[MAX_NUMNODES] __cacheline_aligned;
 extern pg_data_t *pgdat_list[MAX_NUMNODES];