[PATCH 0/6] x86: Reduce Memory Usage and Inter-Node message traffic

[PATCH 0/6] x86: Reduce Memory Usage and Inter-Node message traffic

[travis]

In x86_64 and i386 architectures most arrays that are sized
using NR_CPUS lay in local memory on node 0.  Not only will most
(99%?) of the systems not use all the slots in these arrays,
particularly when NR_CPUS is increased to accommodate future
very high cpu count systems, but a number of cache lines are
passed unnecessarily on the system bus when these arrays are
referenced by cpus on other nodes.

Typically, the values in these arrays are referenced by the cpu
accessing it's own values, though when passing IPI interrupts,
the cpu does access the data relevant to the targeted cpu/node.
Of course, if the referencing cpu is not on node 0, then the
reference will still require cross node exchanges of cache
lines.  A common use of this is for an interrupt service
routine to pass the interrupt to other cpus local to that node.

Ideally, all the elements in these arrays should be moved to the
per_cpu data area.  In some cases (such as x86_cpu_to_apicid)
the array is referenced before the per_cpu data areas are setup.
In this case, a static array is declared in the __initdata
area and initialized by the booting cpu (BSP).  The values are
then moved to the per_cpu area after it is initialized and the
original static array is freed with the rest of the __initdata.

Patches applied to: linux-2.6.23-rc2-mm2
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[PATCH 1/6] x86: Convert cpu_core_map to be a per cpu variable

[travis]

[-- Attachment #1: convert-cpu_core_map-to-per_cpu_data --]
[-- Type: text/plain, Size: 14854 bytes --]

This is from an earlier message from 'Christoph Lameter':

    cpu_core_map is currently an array defined using NR_CPUS. This means that
    we overallocate since we will rarely really use maximum configured cpu.

    If we put the cpu_core_map into the per cpu area then it will be allocated
    for each processor as it comes online.

    This means that the core map cannot be accessed until the per cpu area
    has been allocated. Xen does a weird thing here looping over all processors
    and zeroing the masks that are not yet allocated and that will be zeroed
    when they are allocated. I commented the code out.

    Signed-off-by: Christoph Lameter <clameter@sgi.com>

Signed-off-by: Mike Travis <travis@sgi.com>
---
 arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c |    2 -
 arch/i386/kernel/cpu/cpufreq/powernow-k8.c  |   10 ++++----
 arch/i386/kernel/cpu/proc.c                 |    3 +-
 arch/i386/kernel/smpboot.c                  |   34 ++++++++++++++--------------
 arch/i386/xen/smp.c                         |   14 +++++++++--
 arch/x86_64/kernel/mce_amd.c                |    6 ++--
 arch/x86_64/kernel/setup.c                  |    3 +-
 arch/x86_64/kernel/smpboot.c                |   24 +++++++++----------
 include/asm-i386/smp.h                      |    2 -
 include/asm-i386/topology.h                 |    2 -
 include/asm-x86_64/smp.h                    |    8 +++++-
 include/asm-x86_64/topology.h               |    2 -
 12 files changed, 64 insertions(+), 46 deletions(-)

--- a/include/asm-x86_64/smp.h
+++ b/include/asm-x86_64/smp.h
@@ -39,7 +39,13 @@ extern int smp_num_siblings;
 extern void smp_send_reschedule(int cpu);
 
 extern cpumask_t cpu_sibling_map[NR_CPUS];
-extern cpumask_t cpu_core_map[NR_CPUS];
+/*
+ * cpu_core_map lives in a per cpu area
+ *
+ * extern cpumask_t cpu_core_map[NR_CPUS];
+ */
+DECLARE_PER_CPU(cpumask_t, cpu_core_map);
+
 extern u8 cpu_llc_id[NR_CPUS];
 
 #define SMP_TRAMPOLINE_BASE 0x6000
--- a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -595,7 +595,7 @@ static int acpi_cpufreq_cpu_init(struct 
 	dmi_check_system(sw_any_bug_dmi_table);
 	if (bios_with_sw_any_bug && cpus_weight(policy->cpus) == 1) {
 		policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
-		policy->cpus = cpu_core_map[cpu];
+		policy->cpus = per_cpu(cpu_core_map, cpu);
 	}
 #endif
 
--- a/arch/i386/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/i386/kernel/cpu/cpufreq/powernow-k8.c
@@ -57,7 +57,7 @@ static struct powernow_k8_data *powernow
 static int cpu_family = CPU_OPTERON;
 
 #ifndef CONFIG_SMP
-static cpumask_t cpu_core_map[1];
+DEFINE_PER_CPU(cpumask_t, cpu_core_map)
 #endif
 
 /* Return a frequency in MHz, given an input fid */
@@ -667,7 +667,7 @@ static int fill_powernow_table(struct po
 
 	dprintk("cfid 0x%x, cvid 0x%x\n", data->currfid, data->currvid);
 	data->powernow_table = powernow_table;
-	if (first_cpu(cpu_core_map[data->cpu]) == data->cpu)
+	if (first_cpu(per_cpu(cpu_core_map, data->cpu)) == data->cpu)
 		print_basics(data);
 
 	for (j = 0; j < data->numps; j++)
@@ -821,7 +821,7 @@ static int powernow_k8_cpu_init_acpi(str
 
 	/* fill in data */
 	data->numps = data->acpi_data.state_count;
-	if (first_cpu(cpu_core_map[data->cpu]) == data->cpu)
+	if (first_cpu(per_cpu(cpu_core_map, data->cpu)) == data->cpu)
 		print_basics(data);
 	powernow_k8_acpi_pst_values(data, 0);
 
@@ -1214,7 +1214,7 @@ static int __cpuinit powernowk8_cpu_init
 	if (cpu_family == CPU_HW_PSTATE)
 		pol->cpus = cpumask_of_cpu(pol->cpu);
 	else
-		pol->cpus = cpu_core_map[pol->cpu];
+		pol->cpus = per_cpu(cpu_core_map, pol->cpu);
 	data->available_cores = &(pol->cpus);
 
 	/* Take a crude guess here.
@@ -1281,7 +1281,7 @@ static unsigned int powernowk8_get (unsi
 	cpumask_t oldmask = current->cpus_allowed;
 	unsigned int khz = 0;
 
-	data = powernow_data[first_cpu(cpu_core_map[cpu])];
+	data = powernow_data[first_cpu(per_cpu(cpu_core_map, cpu))];
 
 	if (!data)
 		return -EINVAL;
--- a/arch/i386/kernel/cpu/proc.c
+++ b/arch/i386/kernel/cpu/proc.c
@@ -122,7 +122,8 @@ static int show_cpuinfo(struct seq_file 
 #ifdef CONFIG_X86_HT
 	if (c->x86_max_cores * smp_num_siblings > 1) {
 		seq_printf(m, "physical id\t: %d\n", c->phys_proc_id);
-		seq_printf(m, "siblings\t: %d\n", cpus_weight(cpu_core_map[n]));
+		seq_printf(m, "siblings\t: %d\n",
+				cpus_weight(per_cpu(cpu_core_map, n)));
 		seq_printf(m, "core id\t\t: %d\n", c->cpu_core_id);
 		seq_printf(m, "cpu cores\t: %d\n", c->booted_cores);
 	}
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -74,8 +74,8 @@ cpumask_t cpu_sibling_map[NR_CPUS] __rea
 EXPORT_SYMBOL(cpu_sibling_map);
 
 /* representing HT and core siblings of each logical CPU */
-cpumask_t cpu_core_map[NR_CPUS] __read_mostly;
-EXPORT_SYMBOL(cpu_core_map);
+DEFINE_PER_CPU(cpumask_t, cpu_core_map);
+EXPORT_PER_CPU_SYMBOL(cpu_core_map);
 
 /* bitmap of online cpus */
 cpumask_t cpu_online_map __read_mostly;
@@ -300,7 +300,7 @@ cpumask_t cpu_coregroup_map(int cpu)
 	 * And for power savings, we return cpu_core_map
 	 */
 	if (sched_mc_power_savings || sched_smt_power_savings)
-		return cpu_core_map[cpu];
+		return per_cpu(cpu_core_map, cpu);
 	else
 		return c->llc_shared_map;
 }
@@ -321,8 +321,8 @@ void __cpuinit set_cpu_sibling_map(int c
 			    c[cpu].cpu_core_id == c[i].cpu_core_id) {
 				cpu_set(i, cpu_sibling_map[cpu]);
 				cpu_set(cpu, cpu_sibling_map[i]);
-				cpu_set(i, cpu_core_map[cpu]);
-				cpu_set(cpu, cpu_core_map[i]);
+				cpu_set(i, per_cpu(cpu_core_map, cpu));
+				cpu_set(cpu, per_cpu(cpu_core_map, i));
 				cpu_set(i, c[cpu].llc_shared_map);
 				cpu_set(cpu, c[i].llc_shared_map);
 			}
@@ -334,7 +334,7 @@ void __cpuinit set_cpu_sibling_map(int c
 	cpu_set(cpu, c[cpu].llc_shared_map);
 
 	if (current_cpu_data.x86_max_cores == 1) {
-		cpu_core_map[cpu] = cpu_sibling_map[cpu];
+		per_cpu(cpu_core_map, cpu) = cpu_sibling_map[cpu];
 		c[cpu].booted_cores = 1;
 		return;
 	}
@@ -346,8 +346,8 @@ void __cpuinit set_cpu_sibling_map(int c
 			cpu_set(cpu, c[i].llc_shared_map);
 		}
 		if (c[cpu].phys_proc_id == c[i].phys_proc_id) {
-			cpu_set(i, cpu_core_map[cpu]);
-			cpu_set(cpu, cpu_core_map[i]);
+			cpu_set(i, per_cpu(cpu_core_map, cpu));
+			cpu_set(cpu, per_cpu(cpu_core_map, i));
 			/*
 			 *  Does this new cpu bringup a new core?
 			 */
@@ -984,7 +984,7 @@ static void __init smp_boot_cpus(unsigne
 					   " Using dummy APIC emulation.\n");
 		map_cpu_to_logical_apicid();
 		cpu_set(0, cpu_sibling_map[0]);
-		cpu_set(0, cpu_core_map[0]);
+		cpu_set(0, per_cpu(cpu_core_map, 0));
 		return;
 	}
 
@@ -1009,7 +1009,7 @@ static void __init smp_boot_cpus(unsigne
 		smpboot_clear_io_apic_irqs();
 		phys_cpu_present_map = physid_mask_of_physid(0);
 		cpu_set(0, cpu_sibling_map[0]);
-		cpu_set(0, cpu_core_map[0]);
+		cpu_set(0, per_cpu(cpu_core_map, 0));
 		return;
 	}
 
@@ -1024,7 +1024,7 @@ static void __init smp_boot_cpus(unsigne
 		smpboot_clear_io_apic_irqs();
 		phys_cpu_present_map = physid_mask_of_physid(0);
 		cpu_set(0, cpu_sibling_map[0]);
-		cpu_set(0, cpu_core_map[0]);
+		cpu_set(0, per_cpu(cpu_core_map, 0));
 		return;
 	}
 
@@ -1107,11 +1107,11 @@ static void __init smp_boot_cpus(unsigne
 	 */
 	for (cpu = 0; cpu < NR_CPUS; cpu++) {
 		cpus_clear(cpu_sibling_map[cpu]);
-		cpus_clear(cpu_core_map[cpu]);
+		cpus_clear(per_cpu(cpu_core_map, cpu));
 	}
 
 	cpu_set(0, cpu_sibling_map[0]);
-	cpu_set(0, cpu_core_map[0]);
+	cpu_set(0, per_cpu(cpu_core_map, 0));
 
 	smpboot_setup_io_apic();
 
@@ -1148,9 +1148,9 @@ void remove_siblinginfo(int cpu)
 	int sibling;
 	struct cpuinfo_x86 *c = cpu_data;
 
-	for_each_cpu_mask(sibling, cpu_core_map[cpu]) {
-		cpu_clear(cpu, cpu_core_map[sibling]);
-		/*
+	for_each_cpu_mask(sibling, per_cpu(cpu_core_map, cpu)) {
+		cpu_clear(cpu, per_cpu(cpu_core_map, sibling));
+		/*/
 		 * last thread sibling in this cpu core going down
 		 */
 		if (cpus_weight(cpu_sibling_map[cpu]) == 1)
@@ -1160,7 +1160,7 @@ void remove_siblinginfo(int cpu)
 	for_each_cpu_mask(sibling, cpu_sibling_map[cpu])
 		cpu_clear(cpu, cpu_sibling_map[sibling]);
 	cpus_clear(cpu_sibling_map[cpu]);
-	cpus_clear(cpu_core_map[cpu]);
+	cpus_clear(per_cpu(cpu_core_map, cpu));
 	c[cpu].phys_proc_id = 0;
 	c[cpu].cpu_core_id = 0;
 	cpu_clear(cpu, cpu_sibling_setup_map);
--- a/arch/i386/xen/smp.c
+++ b/arch/i386/xen/smp.c
@@ -148,7 +148,12 @@ void __init xen_smp_prepare_boot_cpu(voi
 
 	for (cpu = 0; cpu < NR_CPUS; cpu++) {
 		cpus_clear(cpu_sibling_map[cpu]);
-		cpus_clear(cpu_core_map[cpu]);
+		/*
+		 * cpu_core_map lives in a per cpu area that is cleared
+		 * when the per cpu array is allocated.
+		 *
+		 * cpus_clear(per_cpu(cpu_core_map, cpu));
+		 */
 	}
 
 	xen_setup_vcpu_info_placement();
@@ -160,7 +165,12 @@ void __init xen_smp_prepare_cpus(unsigne
 
 	for (cpu = 0; cpu < NR_CPUS; cpu++) {
 		cpus_clear(cpu_sibling_map[cpu]);
-		cpus_clear(cpu_core_map[cpu]);
+		/*
+		 * cpu_core_ map will be zeroed when the per
+		 * cpu area is allocated.
+		 *
+		 * cpus_clear(per_cpu(cpu_core_map, cpu));
+		 */
 	}
 
 	smp_store_cpu_info(0);
--- a/arch/x86_64/kernel/mce_amd.c
+++ b/arch/x86_64/kernel/mce_amd.c
@@ -473,7 +473,7 @@ static __cpuinit int threshold_create_ba
 
 #ifdef CONFIG_SMP
 	if (cpu_data[cpu].cpu_core_id && shared_bank[bank]) {	/* symlink */
-		i = first_cpu(cpu_core_map[cpu]);
+		i = first_cpu(per_cpu(cpu_core_map, cpu));
 
 		/* first core not up yet */
 		if (cpu_data[i].cpu_core_id)
@@ -493,7 +493,7 @@ static __cpuinit int threshold_create_ba
 		if (err)
 			goto out;
 
-		b->cpus = cpu_core_map[cpu];
+		b->cpus = per_cpu(cpu_core_map, cpu);
 		per_cpu(threshold_banks, cpu)[bank] = b;
 		goto out;
 	}
@@ -510,7 +510,7 @@ static __cpuinit int threshold_create_ba
 #ifndef CONFIG_SMP
 	b->cpus = CPU_MASK_ALL;
 #else
-	b->cpus = cpu_core_map[cpu];
+	b->cpus = per_cpu(cpu_core_map, cpu);
 #endif
 	err = kobject_register(&b->kobj);
 	if (err)
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -1089,7 +1089,8 @@ static int show_cpuinfo(struct seq_file 
 	if (smp_num_siblings * c->x86_max_cores > 1) {
 		int cpu = c - cpu_data;
 		seq_printf(m, "physical id\t: %d\n", c->phys_proc_id);
-		seq_printf(m, "siblings\t: %d\n", cpus_weight(cpu_core_map[cpu]));
+		seq_printf(m, "siblings\t: %d\n",
+			       cpus_weight(per_cpu(cpu_core_map, cpu)));
 		seq_printf(m, "core id\t\t: %d\n", c->cpu_core_id);
 		seq_printf(m, "cpu cores\t: %d\n", c->booted_cores);
 	}
--- a/arch/x86_64/kernel/smpboot.c
+++ b/arch/x86_64/kernel/smpboot.c
@@ -95,8 +95,8 @@ cpumask_t cpu_sibling_map[NR_CPUS] __rea
 EXPORT_SYMBOL(cpu_sibling_map);
 
 /* representing HT and core siblings of each logical CPU */
-cpumask_t cpu_core_map[NR_CPUS] __read_mostly;
-EXPORT_SYMBOL(cpu_core_map);
+DEFINE_PER_CPU(cpumask_t, cpu_core_map);
+EXPORT_PER_CPU_SYMBOL(cpu_core_map);
 
 /*
  * Trampoline 80x86 program as an array.
@@ -245,7 +245,7 @@ cpumask_t cpu_coregroup_map(int cpu)
 	 * And for power savings, we return cpu_core_map
 	 */
 	if (sched_mc_power_savings || sched_smt_power_savings)
-		return cpu_core_map[cpu];
+		return per_cpu(cpu_core_map, cpu);
 	else
 		return c->llc_shared_map;
 }
@@ -266,8 +266,8 @@ static inline void set_cpu_sibling_map(i
 			    c[cpu].cpu_core_id == c[i].cpu_core_id) {
 				cpu_set(i, cpu_sibling_map[cpu]);
 				cpu_set(cpu, cpu_sibling_map[i]);
-				cpu_set(i, cpu_core_map[cpu]);
-				cpu_set(cpu, cpu_core_map[i]);
+				cpu_set(i, per_cpu(cpu_core_map, cpu));
+				cpu_set(cpu, per_cpu(cpu_core_map, i));
 				cpu_set(i, c[cpu].llc_shared_map);
 				cpu_set(cpu, c[i].llc_shared_map);
 			}
@@ -279,7 +279,7 @@ static inline void set_cpu_sibling_map(i
 	cpu_set(cpu, c[cpu].llc_shared_map);
 
 	if (current_cpu_data.x86_max_cores == 1) {
-		cpu_core_map[cpu] = cpu_sibling_map[cpu];
+		per_cpu(cpu_core_map, cpu) = cpu_sibling_map[cpu];
 		c[cpu].booted_cores = 1;
 		return;
 	}
@@ -291,8 +291,8 @@ static inline void set_cpu_sibling_map(i
 			cpu_set(cpu, c[i].llc_shared_map);
 		}
 		if (c[cpu].phys_proc_id == c[i].phys_proc_id) {
-			cpu_set(i, cpu_core_map[cpu]);
-			cpu_set(cpu, cpu_core_map[i]);
+			cpu_set(i, per_cpu(cpu_core_map, cpu));
+			cpu_set(cpu, per_cpu(cpu_core_map, i));
 			/*
 			 *  Does this new cpu bringup a new core?
 			 */
@@ -742,7 +742,7 @@ static __init void disable_smp(void)
 	else
 		phys_cpu_present_map = physid_mask_of_physid(0);
 	cpu_set(0, cpu_sibling_map[0]);
-	cpu_set(0, cpu_core_map[0]);
+	cpu_set(0, per_cpu(cpu_core_map, 0));
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -977,8 +977,8 @@ static void remove_siblinginfo(int cpu)
 	int sibling;
 	struct cpuinfo_x86 *c = cpu_data;
 
-	for_each_cpu_mask(sibling, cpu_core_map[cpu]) {
-		cpu_clear(cpu, cpu_core_map[sibling]);
+	for_each_cpu_mask(sibling, per_cpu(cpu_core_map, cpu)) {
+		cpu_clear(cpu, per_cpu(cpu_core_map, sibling));
 		/*
 		 * last thread sibling in this cpu core going down
 		 */
@@ -989,7 +989,7 @@ static void remove_siblinginfo(int cpu)
 	for_each_cpu_mask(sibling, cpu_sibling_map[cpu])
 		cpu_clear(cpu, cpu_sibling_map[sibling]);
 	cpus_clear(cpu_sibling_map[cpu]);
-	cpus_clear(cpu_core_map[cpu]);
+	cpus_clear(per_cpu(cpu_core_map, cpu));
 	c[cpu].phys_proc_id = 0;
 	c[cpu].cpu_core_id = 0;
 	cpu_clear(cpu, cpu_sibling_setup_map);
--- a/include/asm-i386/smp.h
+++ b/include/asm-i386/smp.h
@@ -31,7 +31,7 @@ extern void smp_alloc_memory(void);
 extern int pic_mode;
 extern int smp_num_siblings;
 extern cpumask_t cpu_sibling_map[];
-extern cpumask_t cpu_core_map[];
+DECLARE_PER_CPU(cpumask_t, cpu_core_map);
 
 extern void (*mtrr_hook) (void);
 extern void zap_low_mappings (void);
--- a/include/asm-i386/topology.h
+++ b/include/asm-i386/topology.h
@@ -30,7 +30,7 @@
 #ifdef CONFIG_X86_HT
 #define topology_physical_package_id(cpu)	(cpu_data[cpu].phys_proc_id)
 #define topology_core_id(cpu)			(cpu_data[cpu].cpu_core_id)
-#define topology_core_siblings(cpu)		(cpu_core_map[cpu])
+#define topology_core_siblings(cpu)		(per_cpu(cpu_core_map, cpu))
 #define topology_thread_siblings(cpu)		(cpu_sibling_map[cpu])
 #endif
 
--- a/include/asm-x86_64/topology.h
+++ b/include/asm-x86_64/topology.h
@@ -71,7 +71,7 @@ static inline void set_mp_bus_to_node(in
 #ifdef CONFIG_SMP
 #define topology_physical_package_id(cpu)	(cpu_data[cpu].phys_proc_id)
 #define topology_core_id(cpu)			(cpu_data[cpu].cpu_core_id)
-#define topology_core_siblings(cpu)		(cpu_core_map[cpu])
+#define topology_core_siblings(cpu)		(per_cpu(cpu_core_map, cpu))
 #define topology_thread_siblings(cpu)		(cpu_sibling_map[cpu])
 #define mc_capable()			(boot_cpu_data.x86_max_cores > 1)
 #define smt_capable() 			(smp_num_siblings > 1)

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[PATCH 2/6] x86: Convert cpu_sibling_map to be a per cpu variable

[travis]

[-- Attachment #1: convert-cpu_sibling_map-to-per_cpu_data --]
[-- Type: text/plain, Size: 14470 bytes --]

Convert cpu_sibling_map from a static array sized by NR_CPUS to a
per_cpu variable.  This saves sizeof(cpumask_t) * NR unused cpus.
Access is mostly from startup and CPU HOTPLUG functions.

Signed-off-by: Mike Travis <travis@sgi.com>
---
 arch/i386/kernel/cpu/cpufreq/p4-clockmod.c   |    2 -
 arch/i386/kernel/cpu/cpufreq/speedstep-ich.c |    2 -
 arch/i386/kernel/io_apic.c                   |    4 +--
 arch/i386/kernel/smpboot.c                   |   36 +++++++++++++--------------
 arch/i386/oprofile/op_model_p4.c             |    2 -
 arch/i386/xen/smp.c                          |    4 +--
 arch/x86_64/kernel/smpboot.c                 |   26 +++++++++----------
 block/blktrace.c                             |    2 -
 include/asm-i386/smp.h                       |    2 -
 include/asm-i386/topology.h                  |    2 -
 include/asm-x86_64/smp.h                     |    6 +++-
 include/asm-x86_64/topology.h                |    2 -
 kernel/sched.c                               |    8 +++---
 13 files changed, 50 insertions(+), 48 deletions(-)

--- a/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c
+++ b/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c
@@ -200,7 +200,7 @@ static int cpufreq_p4_cpu_init(struct cp
 	unsigned int i;
 
 #ifdef CONFIG_SMP
-	policy->cpus = cpu_sibling_map[policy->cpu];
+	policy->cpus = per_cpu(cpu_sibling_map, policy->cpu);
 #endif
 
 	/* Errata workaround */
--- a/arch/i386/kernel/cpu/cpufreq/speedstep-ich.c
+++ b/arch/i386/kernel/cpu/cpufreq/speedstep-ich.c
@@ -322,7 +322,7 @@ static int speedstep_cpu_init(struct cpu
 
 	/* only run on CPU to be set, or on its sibling */
 #ifdef CONFIG_SMP
-	policy->cpus = cpu_sibling_map[policy->cpu];
+	policy->cpus = per_cpu(cpu_sibling_map, policy->cpu);
 #endif
 
 	cpus_allowed = current->cpus_allowed;
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -378,7 +378,7 @@ static struct irq_cpu_info {
 
 #define IRQ_ALLOWED(cpu, allowed_mask)	cpu_isset(cpu, allowed_mask)
 
-#define CPU_TO_PACKAGEINDEX(i) (first_cpu(cpu_sibling_map[i]))
+#define CPU_TO_PACKAGEINDEX(i) (first_cpu(per_cpu(cpu_sibling_map, i)))
 
 static cpumask_t balance_irq_affinity[NR_IRQS] = {
 	[0 ... NR_IRQS-1] = CPU_MASK_ALL
@@ -598,7 +598,7 @@ tryanotherirq:
 	 * (A+B)/2 vs B
 	 */
 	load = CPU_IRQ(min_loaded) >> 1;
-	for_each_cpu_mask(j, cpu_sibling_map[min_loaded]) {
+	for_each_cpu_mask(j, per_cpu(cpu_sibling_map, min_loaded)) {
 		if (load > CPU_IRQ(j)) {
 			/* This won't change cpu_sibling_map[min_loaded] */
 			load = CPU_IRQ(j);
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -70,8 +70,8 @@ EXPORT_SYMBOL(smp_num_siblings);
 int cpu_llc_id[NR_CPUS] __cpuinitdata = {[0 ... NR_CPUS-1] = BAD_APICID};
 
 /* representing HT siblings of each logical CPU */
-cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly;
-EXPORT_SYMBOL(cpu_sibling_map);
+DEFINE_PER_CPU(cpumask_t, cpu_sibling_map);
+EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
 
 /* representing HT and core siblings of each logical CPU */
 DEFINE_PER_CPU(cpumask_t, cpu_core_map);
@@ -319,8 +319,8 @@ void __cpuinit set_cpu_sibling_map(int c
 		for_each_cpu_mask(i, cpu_sibling_setup_map) {
 			if (c[cpu].phys_proc_id == c[i].phys_proc_id &&
 			    c[cpu].cpu_core_id == c[i].cpu_core_id) {
-				cpu_set(i, cpu_sibling_map[cpu]);
-				cpu_set(cpu, cpu_sibling_map[i]);
+				cpu_set(i, per_cpu(cpu_sibling_map, cpu));
+				cpu_set(cpu, per_cpu(cpu_sibling_map, i));
 				cpu_set(i, per_cpu(cpu_core_map, cpu));
 				cpu_set(cpu, per_cpu(cpu_core_map, i));
 				cpu_set(i, c[cpu].llc_shared_map);
@@ -328,13 +328,13 @@ void __cpuinit set_cpu_sibling_map(int c
 			}
 		}
 	} else {
-		cpu_set(cpu, cpu_sibling_map[cpu]);
+		cpu_set(cpu, per_cpu(cpu_sibling_map, cpu));
 	}
 
 	cpu_set(cpu, c[cpu].llc_shared_map);
 
 	if (current_cpu_data.x86_max_cores == 1) {
-		per_cpu(cpu_core_map, cpu) = cpu_sibling_map[cpu];
+		per_cpu(cpu_core_map, cpu) = per_cpu(cpu_sibling_map, cpu);
 		c[cpu].booted_cores = 1;
 		return;
 	}
@@ -351,12 +351,12 @@ void __cpuinit set_cpu_sibling_map(int c
 			/*
 			 *  Does this new cpu bringup a new core?
 			 */
-			if (cpus_weight(cpu_sibling_map[cpu]) == 1) {
+			if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1) {
 				/*
 				 * for each core in package, increment
 				 * the booted_cores for this new cpu
 				 */
-				if (first_cpu(cpu_sibling_map[i]) == i)
+				if (first_cpu(per_cpu(cpu_sibling_map, i)) == i)
 					c[cpu].booted_cores++;
 				/*
 				 * increment the core count for all
@@ -983,7 +983,7 @@ static void __init smp_boot_cpus(unsigne
 			printk(KERN_NOTICE "Local APIC not detected."
 					   " Using dummy APIC emulation.\n");
 		map_cpu_to_logical_apicid();
-		cpu_set(0, cpu_sibling_map[0]);
+		cpu_set(0, per_cpu(cpu_sibling_map, 0));
 		cpu_set(0, per_cpu(cpu_core_map, 0));
 		return;
 	}
@@ -1008,7 +1008,7 @@ static void __init smp_boot_cpus(unsigne
 		printk(KERN_ERR "... forcing use of dummy APIC emulation. (tell your hw vendor)\n");
 		smpboot_clear_io_apic_irqs();
 		phys_cpu_present_map = physid_mask_of_physid(0);
-		cpu_set(0, cpu_sibling_map[0]);
+		cpu_set(0, per_cpu(cpu_sibling_map, 0));
 		cpu_set(0, per_cpu(cpu_core_map, 0));
 		return;
 	}
@@ -1023,7 +1023,7 @@ static void __init smp_boot_cpus(unsigne
 		printk(KERN_INFO "SMP mode deactivated, forcing use of dummy APIC emulation.\n");
 		smpboot_clear_io_apic_irqs();
 		phys_cpu_present_map = physid_mask_of_physid(0);
-		cpu_set(0, cpu_sibling_map[0]);
+		cpu_set(0, per_cpu(cpu_sibling_map, 0));
 		cpu_set(0, per_cpu(cpu_core_map, 0));
 		return;
 	}
@@ -1102,15 +1102,15 @@ static void __init smp_boot_cpus(unsigne
 	Dprintk("Boot done.\n");
 
 	/*
-	 * construct cpu_sibling_map[], so that we can tell sibling CPUs
+	 * construct cpu_sibling_map, so that we can tell sibling CPUs
 	 * efficiently.
 	 */
 	for (cpu = 0; cpu < NR_CPUS; cpu++) {
-		cpus_clear(cpu_sibling_map[cpu]);
+		cpus_clear(per_cpu(cpu_sibling_map, cpu));
 		cpus_clear(per_cpu(cpu_core_map, cpu));
 	}
 
-	cpu_set(0, cpu_sibling_map[0]);
+	cpu_set(0, per_cpu(cpu_sibling_map, 0));
 	cpu_set(0, per_cpu(cpu_core_map, 0));
 
 	smpboot_setup_io_apic();
@@ -1153,13 +1153,13 @@ void remove_siblinginfo(int cpu)
 		/*/
 		 * last thread sibling in this cpu core going down
 		 */
-		if (cpus_weight(cpu_sibling_map[cpu]) == 1)
+		if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1)
 			c[sibling].booted_cores--;
 	}
 			
-	for_each_cpu_mask(sibling, cpu_sibling_map[cpu])
-		cpu_clear(cpu, cpu_sibling_map[sibling]);
-	cpus_clear(cpu_sibling_map[cpu]);
+	for_each_cpu_mask(sibling, per_cpu(cpu_sibling_map, cpu))
+		cpu_clear(cpu, per_cpu(cpu_sibling_map, sibling));
+	cpus_clear(per_cpu(cpu_sibling_map, cpu));
 	cpus_clear(per_cpu(cpu_core_map, cpu));
 	c[cpu].phys_proc_id = 0;
 	c[cpu].cpu_core_id = 0;
--- a/arch/i386/oprofile/op_model_p4.c
+++ b/arch/i386/oprofile/op_model_p4.c
@@ -379,7 +379,7 @@ static unsigned int get_stagger(void)
 {
 #ifdef CONFIG_SMP
 	int cpu = smp_processor_id();
-	return (cpu != first_cpu(cpu_sibling_map[cpu]));
+	return (cpu != first_cpu(per_cpu(cpu_sibling_map, cpu)));
 #endif	
 	return 0;
 }
--- a/arch/i386/xen/smp.c
+++ b/arch/i386/xen/smp.c
@@ -147,7 +147,7 @@ void __init xen_smp_prepare_boot_cpu(voi
 	make_lowmem_page_readwrite(&per_cpu__gdt_page);
 
 	for (cpu = 0; cpu < NR_CPUS; cpu++) {
-		cpus_clear(cpu_sibling_map[cpu]);
+		cpus_clear(per_cpu(cpu_sibling_map, cpu));
 		/*
 		 * cpu_core_map lives in a per cpu area that is cleared
 		 * when the per cpu array is allocated.
@@ -164,7 +164,7 @@ void __init xen_smp_prepare_cpus(unsigne
 	unsigned cpu;
 
 	for (cpu = 0; cpu < NR_CPUS; cpu++) {
-		cpus_clear(cpu_sibling_map[cpu]);
+		cpus_clear(per_cpu(cpu_sibling_map, cpu));
 		/*
 		 * cpu_core_ map will be zeroed when the per
 		 * cpu area is allocated.
--- a/arch/x86_64/kernel/smpboot.c
+++ b/arch/x86_64/kernel/smpboot.c
@@ -91,8 +91,8 @@ EXPORT_SYMBOL(cpu_data);
 int smp_threads_ready;
 
 /* representing HT siblings of each logical CPU */
-cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly;
-EXPORT_SYMBOL(cpu_sibling_map);
+DEFINE_PER_CPU(cpumask_t, cpu_sibling_map);
+EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
 
 /* representing HT and core siblings of each logical CPU */
 DEFINE_PER_CPU(cpumask_t, cpu_core_map);
@@ -264,8 +264,8 @@ static inline void set_cpu_sibling_map(i
 		for_each_cpu_mask(i, cpu_sibling_setup_map) {
 			if (c[cpu].phys_proc_id == c[i].phys_proc_id &&
 			    c[cpu].cpu_core_id == c[i].cpu_core_id) {
-				cpu_set(i, cpu_sibling_map[cpu]);
-				cpu_set(cpu, cpu_sibling_map[i]);
+				cpu_set(i, per_cpu(cpu_sibling_map, cpu));
+				cpu_set(cpu, per_cpu(cpu_sibling_map, i));
 				cpu_set(i, per_cpu(cpu_core_map, cpu));
 				cpu_set(cpu, per_cpu(cpu_core_map, i));
 				cpu_set(i, c[cpu].llc_shared_map);
@@ -273,13 +273,13 @@ static inline void set_cpu_sibling_map(i
 			}
 		}
 	} else {
-		cpu_set(cpu, cpu_sibling_map[cpu]);
+		cpu_set(cpu, per_cpu(cpu_sibling_map, cpu));
 	}
 
 	cpu_set(cpu, c[cpu].llc_shared_map);
 
 	if (current_cpu_data.x86_max_cores == 1) {
-		per_cpu(cpu_core_map, cpu) = cpu_sibling_map[cpu];
+		per_cpu(cpu_core_map, cpu) = per_cpu(cpu_sibling_map, cpu);
 		c[cpu].booted_cores = 1;
 		return;
 	}
@@ -296,12 +296,12 @@ static inline void set_cpu_sibling_map(i
 			/*
 			 *  Does this new cpu bringup a new core?
 			 */
-			if (cpus_weight(cpu_sibling_map[cpu]) == 1) {
+			if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1) {
 				/*
 				 * for each core in package, increment
 				 * the booted_cores for this new cpu
 				 */
-				if (first_cpu(cpu_sibling_map[i]) == i)
+				if (first_cpu(per_cpu(cpu_sibling_map, i)) == i)
 					c[cpu].booted_cores++;
 				/*
 				 * increment the core count for all
@@ -741,7 +741,7 @@ static __init void disable_smp(void)
 		phys_cpu_present_map = physid_mask_of_physid(boot_cpu_id);
 	else
 		phys_cpu_present_map = physid_mask_of_physid(0);
-	cpu_set(0, cpu_sibling_map[0]);
+	cpu_set(0, per_cpu(cpu_sibling_map, 0));
 	cpu_set(0, per_cpu(cpu_core_map, 0));
 }
 
@@ -982,13 +982,13 @@ static void remove_siblinginfo(int cpu)
 		/*
 		 * last thread sibling in this cpu core going down
 		 */
-		if (cpus_weight(cpu_sibling_map[cpu]) == 1)
+		if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1)
 			c[sibling].booted_cores--;
 	}
 			
-	for_each_cpu_mask(sibling, cpu_sibling_map[cpu])
-		cpu_clear(cpu, cpu_sibling_map[sibling]);
-	cpus_clear(cpu_sibling_map[cpu]);
+	for_each_cpu_mask(sibling, per_cpu(cpu_sibling_map, cpu))
+		cpu_clear(cpu, per_cpu(cpu_sibling_map, sibling));
+	cpus_clear(per_cpu(cpu_sibling_map, cpu));
 	cpus_clear(per_cpu(cpu_core_map, cpu));
 	c[cpu].phys_proc_id = 0;
 	c[cpu].cpu_core_id = 0;
--- a/block/blktrace.c
+++ b/block/blktrace.c
@@ -536,7 +536,7 @@ static void blk_trace_set_ht_offsets(voi
 	for_each_online_cpu(cpu) {
 		unsigned long long *cpu_off, *sibling_off;
 
-		for_each_cpu_mask(i, cpu_sibling_map[cpu]) {
+		for_each_cpu_mask(i, per_cpu(cpu_sibling_map, cpu)) {
 			if (i == cpu)
 				continue;
 
--- a/include/asm-i386/smp.h
+++ b/include/asm-i386/smp.h
@@ -30,7 +30,7 @@
 extern void smp_alloc_memory(void);
 extern int pic_mode;
 extern int smp_num_siblings;
-extern cpumask_t cpu_sibling_map[];
+DECLARE_PER_CPU(cpumask_t, cpu_sibling_map);
 DECLARE_PER_CPU(cpumask_t, cpu_core_map);
 
 extern void (*mtrr_hook) (void);
--- a/include/asm-i386/topology.h
+++ b/include/asm-i386/topology.h
@@ -31,7 +31,7 @@
 #define topology_physical_package_id(cpu)	(cpu_data[cpu].phys_proc_id)
 #define topology_core_id(cpu)			(cpu_data[cpu].cpu_core_id)
 #define topology_core_siblings(cpu)		(per_cpu(cpu_core_map, cpu))
-#define topology_thread_siblings(cpu)		(cpu_sibling_map[cpu])
+#define topology_thread_siblings(cpu)		(per_cpu(cpu_sibling_map, cpu))
 #endif
 
 #ifdef CONFIG_NUMA
--- a/include/asm-x86_64/smp.h
+++ b/include/asm-x86_64/smp.h
@@ -38,12 +38,14 @@ extern void unlock_ipi_call_lock(void);
 extern int smp_num_siblings;
 extern void smp_send_reschedule(int cpu);
 
-extern cpumask_t cpu_sibling_map[NR_CPUS];
 /*
- * cpu_core_map lives in a per cpu area
+ * cpu_sibling_map and cpu_core_map now live
+ * in the per cpu area
  *
+ * extern cpumask_t cpu_sibling_map[NR_CPUS];
  * extern cpumask_t cpu_core_map[NR_CPUS];
  */
+DECLARE_PER_CPU(cpumask_t, cpu_sibling_map);
 DECLARE_PER_CPU(cpumask_t, cpu_core_map);
 
 extern u8 cpu_llc_id[NR_CPUS];
--- a/include/asm-x86_64/topology.h
+++ b/include/asm-x86_64/topology.h
@@ -72,7 +72,7 @@ static inline void set_mp_bus_to_node(in
 #define topology_physical_package_id(cpu)	(cpu_data[cpu].phys_proc_id)
 #define topology_core_id(cpu)			(cpu_data[cpu].cpu_core_id)
 #define topology_core_siblings(cpu)		(per_cpu(cpu_core_map, cpu))
-#define topology_thread_siblings(cpu)		(cpu_sibling_map[cpu])
+#define topology_thread_siblings(cpu)		(per_cpu(cpu_sibling_map, cpu))
 #define mc_capable()			(boot_cpu_data.x86_max_cores > 1)
 #define smt_capable() 			(smp_num_siblings > 1)
 #endif
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5822,7 +5822,7 @@ static int cpu_to_core_group(int cpu, co
 			     struct sched_group **sg)
 {
 	int group;
-	cpumask_t mask = cpu_sibling_map[cpu];
+	cpumask_t mask = per_cpu(cpu_sibling_map, cpu);
 	cpus_and(mask, mask, *cpu_map);
 	group = first_cpu(mask);
 	if (sg)
@@ -5851,7 +5851,7 @@ static int cpu_to_phys_group(int cpu, co
 	cpus_and(mask, mask, *cpu_map);
 	group = first_cpu(mask);
 #elif defined(CONFIG_SCHED_SMT)
-	cpumask_t mask = cpu_sibling_map[cpu];
+	cpumask_t mask = per_cpu(cpu_sibling_map, cpu);
 	cpus_and(mask, mask, *cpu_map);
 	group = first_cpu(mask);
 #else
@@ -6086,7 +6086,7 @@ static int build_sched_domains(const cpu
 		p = sd;
 		sd = &per_cpu(cpu_domains, i);
 		*sd = SD_SIBLING_INIT;
-		sd->span = cpu_sibling_map[i];
+		sd->span = per_cpu(cpu_sibling_map, i);
 		cpus_and(sd->span, sd->span, *cpu_map);
 		sd->parent = p;
 		p->child = sd;
@@ -6097,7 +6097,7 @@ static int build_sched_domains(const cpu
 #ifdef CONFIG_SCHED_SMT
 	/* Set up CPU (sibling) groups */
 	for_each_cpu_mask(i, *cpu_map) {
-		cpumask_t this_sibling_map = cpu_sibling_map[i];
+		cpumask_t this_sibling_map = per_cpu(cpu_sibling_map, i);
 		cpus_and(this_sibling_map, this_sibling_map, *cpu_map);
 		if (i != first_cpu(this_sibling_map))
 			continue;

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[PATCH 3/6] x86: Convert x86_cpu_to_apicid to be a per cpu variable

[travis]

[-- Attachment #1: convert-x86_cpu_to_apicid-to-per_cpu_data --]
[-- Type: text/plain, Size: 9965 bytes --]

This patch converts the x86_cpu_to_apicid array to be a per
cpu variable.  This saves sizeof(apicid) * NR unused cpus.
Access is mostly from startup and CPU HOTPLUG functions and
for sending IPI's.

MP_processor_info() is one of the functions that require access
to the x86_cpu_to_apicid array before the per_cpu data area is
setup.  For this case, a pointer to the __initdata array is
initialized in setup_arch() and removed in smp_prepare_cpus()
after the per_cpu data area is initialized.

A second change is included to change the initial array value
of ARCH i386 from 0xff to BAD_APICID to be consistent with
ARCH x86_64.

Signed-off-by: Mike Travis <travis@sgi.com>
---
 arch/i386/kernel/acpi/boot.c      |    2 +-
 arch/i386/kernel/smp.c            |    2 +-
 arch/i386/kernel/smpboot.c        |   22 +++++++++++++++-------
 arch/x86_64/kernel/genapic.c      |   15 ++++++++++++---
 arch/x86_64/kernel/genapic_flat.c |    2 +-
 arch/x86_64/kernel/mpparse.c      |   15 +++++++++++++--
 arch/x86_64/kernel/setup.c        |    5 +++++
 arch/x86_64/kernel/smpboot.c      |   23 ++++++++++++++++++++++-
 arch/x86_64/mm/numa.c             |    2 +-
 include/asm-i386/smp.h            |    6 ++++--
 include/asm-x86_64/ipi.h          |    2 +-
 include/asm-x86_64/smp.h          |    6 ++++--
 12 files changed, 80 insertions(+), 22 deletions(-)

--- a/arch/i386/kernel/acpi/boot.c
+++ b/arch/i386/kernel/acpi/boot.c
@@ -555,7 +555,7 @@ EXPORT_SYMBOL(acpi_map_lsapic);
 
 int acpi_unmap_lsapic(int cpu)
 {
-	x86_cpu_to_apicid[cpu] = -1;
+	per_cpu(x86_cpu_to_apicid, cpu) = -1;
 	cpu_clear(cpu, cpu_present_map);
 	num_processors--;
 
--- a/arch/i386/kernel/smp.c
+++ b/arch/i386/kernel/smp.c
@@ -676,7 +676,7 @@ static int convert_apicid_to_cpu(int api
 	int i;
 
 	for (i = 0; i < NR_CPUS; i++) {
-		if (x86_cpu_to_apicid[i] == apic_id)
+		if (per_cpu(x86_cpu_to_apicid, i) == apic_id)
 			return i;
 	}
 	return -1;
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -92,9 +92,17 @@ static cpumask_t smp_commenced_mask;
 struct cpuinfo_x86 cpu_data[NR_CPUS] __cacheline_aligned;
 EXPORT_SYMBOL(cpu_data);
 
-u8 x86_cpu_to_apicid[NR_CPUS] __read_mostly =
-			{ [0 ... NR_CPUS-1] = 0xff };
-EXPORT_SYMBOL(x86_cpu_to_apicid);
+/*
+ * The following static array is used during kernel startup
+ * and the x86_cpu_to_apicid_ptr contains the address of the
+ * array during this time.  Is it zeroed when the per_cpu
+ * data area is removed.
+ */
+u8 x86_cpu_to_apicid_init[NR_CPUS] __initdata =
+			{ [0 ... NR_CPUS-1] = BAD_APICID };
+void *x86_cpu_to_apicid_ptr;
+DEFINE_PER_CPU(u8, x86_cpu_to_apicid) = BAD_APICID;
+EXPORT_PER_CPU_SYMBOL(x86_cpu_to_apicid);
 
 u8 apicid_2_node[MAX_APICID];
 
@@ -804,7 +812,7 @@ static int __cpuinit do_boot_cpu(int api
 
 	irq_ctx_init(cpu);
 
-	x86_cpu_to_apicid[cpu] = apicid;
+	per_cpu(x86_cpu_to_apicid, cpu) = apicid;
 	/*
 	 * This grunge runs the startup process for
 	 * the targeted processor.
@@ -866,7 +874,7 @@ static int __cpuinit do_boot_cpu(int api
 		cpu_clear(cpu, cpu_initialized); /* was set by cpu_init() */
 		cpucount--;
 	} else {
-		x86_cpu_to_apicid[cpu] = apicid;
+		per_cpu(x86_cpu_to_apicid, cpu) = apicid;
 		cpu_set(cpu, cpu_present_map);
 	}
 
@@ -915,7 +923,7 @@ static int __cpuinit __smp_prepare_cpu(i
 	struct warm_boot_cpu_info info;
 	int	apicid, ret;
 
-	apicid = x86_cpu_to_apicid[cpu];
+	apicid = per_cpu(x86_cpu_to_apicid, cpu);
 	if (apicid == BAD_APICID) {
 		ret = -ENODEV;
 		goto exit;
@@ -965,7 +973,7 @@ static void __init smp_boot_cpus(unsigne
 
 	boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID));
 	boot_cpu_logical_apicid = logical_smp_processor_id();
-	x86_cpu_to_apicid[0] = boot_cpu_physical_apicid;
+	per_cpu(x86_cpu_to_apicid, 0) = boot_cpu_physical_apicid;
 
 	current_thread_info()->cpu = 0;
 
--- a/arch/x86_64/kernel/mpparse.c
+++ b/arch/x86_64/kernel/mpparse.c
@@ -86,7 +86,7 @@ static int __init mpf_checksum(unsigned 
 	return sum & 0xFF;
 }
 
-static void __cpuinit MP_processor_info (struct mpc_config_processor *m)
+static void __cpuinit MP_processor_info(struct mpc_config_processor *m)
 {
 	int cpu;
 	cpumask_t tmp_map;
@@ -123,7 +123,18 @@ static void __cpuinit MP_processor_info 
 		cpu = 0;
  	}
 	bios_cpu_apicid[cpu] = m->mpc_apicid;
-	x86_cpu_to_apicid[cpu] = m->mpc_apicid;
+	/*
+	 * We get called early in the the start_kernel initialization
+	 * process when the per_cpu data area is not yet setup, so we
+	 * use a static array that is removed after the per_cpu data
+	 * area is created.
+	 */
+	if (x86_cpu_to_apicid_ptr) {
+		u8 *x86_cpu_to_apicid = (u8 *)x86_cpu_to_apicid_ptr;
+		x86_cpu_to_apicid[cpu] = m->mpc_apicid;
+	} else {
+		per_cpu(x86_cpu_to_apicid, cpu) = m->mpc_apicid;
+	}
 
 	cpu_set(cpu, cpu_possible_map);
 	cpu_set(cpu, cpu_present_map);
--- a/arch/x86_64/kernel/smpboot.c
+++ b/arch/x86_64/kernel/smpboot.c
@@ -701,7 +701,7 @@ do_rest:
 		clear_node_cpumask(cpu); /* was set by numa_add_cpu */
 		cpu_clear(cpu, cpu_present_map);
 		cpu_clear(cpu, cpu_possible_map);
-		x86_cpu_to_apicid[cpu] = BAD_APICID;
+		per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID;
 		return -EIO;
 	}
 
@@ -848,6 +848,26 @@ static int __init smp_sanity_check(unsig
 }
 
 /*
+ * Copy apicid's found by MP_processor_info from initial array to the per cpu
+ * data area.  The x86_cpu_to_apicid_init array is then expendable and the
+ * x86_cpu_to_apicid_ptr is zeroed indicating that the static array is no
+ * longer available.
+ */
+void __init smp_set_apicids(void)
+{
+	int cpu;
+
+	for_each_cpu_mask(cpu, cpu_possible_map) {
+		if (per_cpu_offset(cpu))
+			per_cpu(x86_cpu_to_apicid, cpu) =
+						x86_cpu_to_apicid_init[cpu];
+	}
+
+	/* indicate the static array will be going away soon */
+	x86_cpu_to_apicid_ptr = NULL;
+}
+
+/*
  * Prepare for SMP bootup.  The MP table or ACPI has been read
  * earlier.  Just do some sanity checking here and enable APIC mode.
  */
@@ -856,6 +876,7 @@ void __init smp_prepare_cpus(unsigned in
 	nmi_watchdog_default();
 	current_cpu_data = boot_cpu_data;
 	current_thread_info()->cpu = 0;  /* needed? */
+	smp_set_apicids();
 	set_cpu_sibling_map(0);
 
 	if (smp_sanity_check(max_cpus) < 0) {
--- a/arch/x86_64/mm/numa.c
+++ b/arch/x86_64/mm/numa.c
@@ -615,7 +615,7 @@ void __init init_cpu_to_node(void)
 {
 	int i;
  	for (i = 0; i < NR_CPUS; i++) {
-		u8 apicid = x86_cpu_to_apicid[i];
+		u8 apicid = x86_cpu_to_apicid_init[i];
 		if (apicid == BAD_APICID)
 			continue;
 		if (apicid_to_node[apicid] == NUMA_NO_NODE)
--- a/include/asm-i386/smp.h
+++ b/include/asm-i386/smp.h
@@ -39,9 +39,11 @@ extern void lock_ipi_call_lock(void);
 extern void unlock_ipi_call_lock(void);
 
 #define MAX_APICID 256
-extern u8 x86_cpu_to_apicid[];
+extern u8 __initdata x86_cpu_to_apicid_init[];
+extern void *x86_cpu_to_apicid_ptr;
+DECLARE_PER_CPU(u8, x86_cpu_to_apicid);
 
-#define cpu_physical_id(cpu)	x86_cpu_to_apicid[cpu]
+#define cpu_physical_id(cpu)	per_cpu(x86_cpu_to_apicid, cpu)
 
 extern void set_cpu_sibling_map(int cpu);
 
--- a/include/asm-x86_64/ipi.h
+++ b/include/asm-x86_64/ipi.h
@@ -119,7 +119,7 @@ static inline void send_IPI_mask_sequenc
 	 */
 	local_irq_save(flags);
 	for_each_cpu_mask(query_cpu, mask) {
-		__send_IPI_dest_field(x86_cpu_to_apicid[query_cpu],
+		__send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, query_cpu),
 				      vector, APIC_DEST_PHYSICAL);
 	}
 	local_irq_restore(flags);
--- a/include/asm-x86_64/smp.h
+++ b/include/asm-x86_64/smp.h
@@ -85,7 +85,9 @@ static inline int hard_smp_processor_id(
  * Some lowlevel functions might want to know about
  * the real APIC ID <-> CPU # mapping.
  */
-extern u8 x86_cpu_to_apicid[NR_CPUS];	/* physical ID */
+extern u8 __initdata x86_cpu_to_apicid_init[];
+extern void *x86_cpu_to_apicid_ptr;
+DECLARE_PER_CPU(u8, x86_cpu_to_apicid);	/* physical ID */
 extern u8 bios_cpu_apicid[];
 
 static inline int cpu_present_to_apicid(int mps_cpu)
@@ -116,7 +118,7 @@ static __inline int logical_smp_processo
 }
 
 #ifdef CONFIG_SMP
-#define cpu_physical_id(cpu)		x86_cpu_to_apicid[cpu]
+#define cpu_physical_id(cpu)		per_cpu(x86_cpu_to_apicid, cpu)
 #else
 #define cpu_physical_id(cpu)		boot_cpu_id
 #endif /* !CONFIG_SMP */
--- a/arch/x86_64/kernel/genapic_flat.c
+++ b/arch/x86_64/kernel/genapic_flat.c
@@ -172,7 +172,7 @@ static unsigned int physflat_cpu_mask_to
 	 */
 	cpu = first_cpu(cpumask);
 	if ((unsigned)cpu < NR_CPUS)
-		return x86_cpu_to_apicid[cpu];
+		return per_cpu(x86_cpu_to_apicid, cpu);
 	else
 		return BAD_APICID;
 }
--- a/arch/x86_64/kernel/genapic.c
+++ b/arch/x86_64/kernel/genapic.c
@@ -24,10 +24,19 @@
 #include <acpi/acpi_bus.h>
 #endif
 
-/* which logical CPU number maps to which CPU (physical APIC ID) */
-u8 x86_cpu_to_apicid[NR_CPUS] __read_mostly
+/*
+ * which logical CPU number maps to which CPU (physical APIC ID)
+ *
+ * The following static array is used during kernel startup
+ * and the x86_cpu_to_apicid_ptr contains the address of the
+ * array during this time.  Is it zeroed when the per_cpu
+ * data area is removed.
+ */
+u8 x86_cpu_to_apicid_init[NR_CPUS] __initdata
 					= { [0 ... NR_CPUS-1] = BAD_APICID };
-EXPORT_SYMBOL(x86_cpu_to_apicid);
+void *x86_cpu_to_apicid_ptr;
+DEFINE_PER_CPU(u8, x86_cpu_to_apicid) = BAD_APICID;
+EXPORT_PER_CPU_SYMBOL(x86_cpu_to_apicid);
 
 struct genapic __read_mostly *genapic = &apic_flat;
 
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -276,6 +276,11 @@ void __init setup_arch(char **cmdline_p)
 
 	dmi_scan_machine();
 
+#ifdef CONFIG_SMP
+	/* setup to use the static apicid table during kernel startup */
+	x86_cpu_to_apicid_ptr = (void *)&x86_cpu_to_apicid_init;
+#endif
+
 #ifdef CONFIG_ACPI
 	/*
 	 * Initialize the ACPI boot-time table parser (gets the RSDP and SDT).

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[PATCH 4/6] x86: Convert cpu_llc_id to be a per cpu variable

[travis]

[-- Attachment #1: convert-cpu_llc_id-to-per_cpu_data --]
[-- Type: text/plain, Size: 3948 bytes --]

Convert cpu_llc_id from a static array sized by NR_CPUS to a
per_cpu variable.  This saves sizeof(cpu_llc_id) * NR unused
cpus.  Access is mostly from startup and CPU HOTPLUG functions.

Note the addtional change of the cpu_llc_id type from u8
to int for ARCH x86_64 to correspond with ARCH i386.

Signed-off-by: Mike Travis <travis@sgi.com>
---
 arch/i386/kernel/cpu/intel_cacheinfo.c |    4 ++--
 arch/i386/kernel/smpboot.c             |    6 +++---
 arch/x86_64/kernel/smpboot.c           |    6 +++---
 include/asm-i386/processor.h           |    6 +++++-
 include/asm-x86_64/smp.h               |    8 +++-----
 5 files changed, 16 insertions(+), 14 deletions(-)

--- a/arch/i386/kernel/cpu/intel_cacheinfo.c
+++ b/arch/i386/kernel/cpu/intel_cacheinfo.c
@@ -417,14 +417,14 @@ unsigned int __cpuinit init_intel_cachei
 	if (new_l2) {
 		l2 = new_l2;
 #ifdef CONFIG_X86_HT
-		cpu_llc_id[cpu] = l2_id;
+		per_cpu(cpu_llc_id, cpu) = l2_id;
 #endif
 	}
 
 	if (new_l3) {
 		l3 = new_l3;
 #ifdef CONFIG_X86_HT
-		cpu_llc_id[cpu] = l3_id;
+		per_cpu(cpu_llc_id, cpu) = l3_id;
 #endif
 	}
 
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -67,7 +67,7 @@ int smp_num_siblings = 1;
 EXPORT_SYMBOL(smp_num_siblings);
 
 /* Last level cache ID of each logical CPU */
-int cpu_llc_id[NR_CPUS] __cpuinitdata = {[0 ... NR_CPUS-1] = BAD_APICID};
+DEFINE_PER_CPU(int, cpu_llc_id) = BAD_APICID;
 
 /* representing HT siblings of each logical CPU */
 DEFINE_PER_CPU(cpumask_t, cpu_sibling_map);
@@ -348,8 +348,8 @@ void __cpuinit set_cpu_sibling_map(int c
 	}
 
 	for_each_cpu_mask(i, cpu_sibling_setup_map) {
-		if (cpu_llc_id[cpu] != BAD_APICID &&
-		    cpu_llc_id[cpu] == cpu_llc_id[i]) {
+		if (per_cpu(cpu_llc_id, cpu) != BAD_APICID &&
+		    per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i)) {
 			cpu_set(i, c[cpu].llc_shared_map);
 			cpu_set(cpu, c[i].llc_shared_map);
 		}
--- a/arch/x86_64/kernel/smpboot.c
+++ b/arch/x86_64/kernel/smpboot.c
@@ -65,7 +65,7 @@ int smp_num_siblings = 1;
 EXPORT_SYMBOL(smp_num_siblings);
 
 /* Last level cache ID of each logical CPU */
-u8 cpu_llc_id[NR_CPUS] __cpuinitdata  = {[0 ... NR_CPUS-1] = BAD_APICID};
+DEFINE_PER_CPU(int, cpu_llc_id) = BAD_APICID;
 
 /* Bitmask of currently online CPUs */
 cpumask_t cpu_online_map __read_mostly;
@@ -285,8 +285,8 @@ static inline void set_cpu_sibling_map(i
 	}
 
 	for_each_cpu_mask(i, cpu_sibling_setup_map) {
-		if (cpu_llc_id[cpu] != BAD_APICID &&
-		    cpu_llc_id[cpu] == cpu_llc_id[i]) {
+		if (per_cpu(cpu_llc_id, cpu) != BAD_APICID &&
+		    per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i)) {
 			cpu_set(i, c[cpu].llc_shared_map);
 			cpu_set(cpu, c[i].llc_shared_map);
 		}
--- a/include/asm-i386/processor.h
+++ b/include/asm-i386/processor.h
@@ -110,7 +110,11 @@ extern struct cpuinfo_x86 cpu_data[];
 #define current_cpu_data boot_cpu_data
 #endif
 
-extern	int cpu_llc_id[NR_CPUS];
+/*
+ * the following now lives in the per cpu area:
+ * extern	int cpu_llc_id[NR_CPUS];
+ */
+DECLARE_PER_CPU(int, cpu_llc_id);
 extern char ignore_fpu_irq;
 
 void __init cpu_detect(struct cpuinfo_x86 *c);
--- a/include/asm-x86_64/smp.h
+++ b/include/asm-x86_64/smp.h
@@ -39,16 +39,14 @@ extern int smp_num_siblings;
 extern void smp_send_reschedule(int cpu);
 
 /*
- * cpu_sibling_map and cpu_core_map now live
- * in the per cpu area
- *
+ * the following now live in the per cpu area:
  * extern cpumask_t cpu_sibling_map[NR_CPUS];
  * extern cpumask_t cpu_core_map[NR_CPUS];
+ * extern u8 cpu_llc_id[NR_CPUS];
  */
 DECLARE_PER_CPU(cpumask_t, cpu_sibling_map);
 DECLARE_PER_CPU(cpumask_t, cpu_core_map);
-
-extern u8 cpu_llc_id[NR_CPUS];
+DECLARE_PER_CPU(int, cpu_llc_id);
 
 #define SMP_TRAMPOLINE_BASE 0x6000
 

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[PATCH 5/6] x86: fix cpu_to_node references

[travis]

[-- Attachment #1: fix-cpu_to_node-refs --]
[-- Type: text/plain, Size: 2077 bytes --]

Fix four instances where cpu_to_node is referenced
by array instead of via the cpu_to_node macro.  This
is preparation to moving it to the per_cpu data area.

Signed-off-by: Mike Travis <travis@sgi.com>
---
 arch/x86_64/kernel/vsyscall.c |    2 +-
 arch/x86_64/mm/numa.c         |    4 ++--
 arch/x86_64/mm/srat.c         |    4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

--- a/arch/x86_64/kernel/vsyscall.c
+++ b/arch/x86_64/kernel/vsyscall.c
@@ -283,7 +283,7 @@ static void __cpuinit vsyscall_set_cpu(i
 	unsigned long *d;
 	unsigned long node = 0;
 #ifdef CONFIG_NUMA
-	node = cpu_to_node[cpu];
+	node = cpu_to_node(cpu);
 #endif
 	if (cpu_has(&cpu_data[cpu], X86_FEATURE_RDTSCP))
 		write_rdtscp_aux((node << 12) | cpu);
--- a/arch/x86_64/mm/numa.c
+++ b/arch/x86_64/mm/numa.c
@@ -264,7 +264,7 @@ void __init numa_init_array(void)
 	   We round robin the existing nodes. */
 	rr = first_node(node_online_map);
 	for (i = 0; i < NR_CPUS; i++) {
-		if (cpu_to_node[i] != NUMA_NO_NODE)
+		if (cpu_to_node(i) != NUMA_NO_NODE)
 			continue;
  		numa_set_node(i, rr);
 		rr = next_node(rr, node_online_map);
@@ -546,7 +546,7 @@ __cpuinit void numa_add_cpu(int cpu)
 void __cpuinit numa_set_node(int cpu, int node)
 {
 	cpu_pda(cpu)->nodenumber = node;
-	cpu_to_node[cpu] = node;
+	cpu_to_node(cpu) = node;
 }
 
 unsigned long __init numa_free_all_bootmem(void) 
--- a/arch/x86_64/mm/srat.c
+++ b/arch/x86_64/mm/srat.c
@@ -431,9 +431,9 @@ int __init acpi_scan_nodes(unsigned long
 			setup_node_bootmem(i, nodes[i].start, nodes[i].end);
 
 	for (i = 0; i < NR_CPUS; i++) {
-		if (cpu_to_node[i] == NUMA_NO_NODE)
+		if (cpu_to_node(i) == NUMA_NO_NODE)
 			continue;
-		if (!node_isset(cpu_to_node[i], node_possible_map))
+		if (!node_isset(cpu_to_node(i), node_possible_map))
 			numa_set_node(i, NUMA_NO_NODE);
 	}
 	numa_init_array();

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[PATCH 6/6] x86: acpi-use-cpu_physical_id

[travis]

[-- Attachment #1: acpi-use-cpu_physical_id --]
[-- Type: text/plain, Size: 1281 bytes --]

This is from an earlier message from Christoph Lameter:

    processor_core.c currently tries to determine the apicid by special casing
    for IA64 and x86. The desired information is readily available via

	    cpu_physical_id()

    on IA64, i386 and x86_64.

    Signed-off-by: Christoph Lameter <clameter@sgi.com>

Signed-off-by: Mike Travis <travis@sgi.com>
---
 drivers/acpi/processor_core.c |    8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -420,12 +420,6 @@ static int map_lsapic_id(struct acpi_sub
 	return 0;
 }
 
-#ifdef CONFIG_IA64
-#define arch_cpu_to_apicid 	ia64_cpu_to_sapicid
-#else
-#define arch_cpu_to_apicid 	x86_cpu_to_apicid
-#endif
-
 static int map_madt_entry(u32 acpi_id)
 {
 	unsigned long madt_end, entry;
@@ -499,7 +493,7 @@ static int get_cpu_id(acpi_handle handle
 		return apic_id;
 
 	for (i = 0; i < NR_CPUS; ++i) {
-		if (arch_cpu_to_apicid[i] == apic_id)
+		if (cpu_physical_id(i) == apic_id)
 			return i;
 	}
 	return -1;

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Re: [PATCH 6/6] x86: acpi-use-cpu_physical_id

[Andi Kleen]

On Wed, Aug 22, 2007 at 10:21:07AM -0700, travis@sgi.com wrote:
> This is from an earlier message from Christoph Lameter:
> 
>     processor_core.c currently tries to determine the apicid by special casing
>     for IA64 and x86. The desired information is readily available via
> 
> 	    cpu_physical_id()
> 
>     on IA64, i386 and x86_64.

Have you tried this with a !CONFIG_SMP build? The drivers/dma code was doing
the same and running into problems because it wasn't defined there.

-Andi

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Re: [PATCH 5/6] x86: fix cpu_to_node references

[Andi Kleen]

On Wed, Aug 22, 2007 at 10:21:06AM -0700, travis@sgi.com wrote:
> Fix four instances where cpu_to_node is referenced
> by array instead of via the cpu_to_node macro.  This
> is preparation to moving it to the per_cpu data area.

Shouldn't this patch be logically before the per cpu 
conversion (which is 3/6). This way the result would
be git bisectable.

-Andi

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Re: [PATCH 4/6] x86: Convert cpu_llc_id to be a per cpu variable

[Andi Kleen]

On Wed, Aug 22, 2007 at 10:21:05AM -0700, travis@sgi.com wrote:
> Note the addtional change of the cpu_llc_id type from u8
> to int for ARCH x86_64 to correspond with ARCH i386.

At least currently it cannot be more than 8 bit. So why
waste memory? It would be better to change i386

-Andi

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