summaryrefslogtreecommitdiffstats
path: root/arch/x86_64/kernel/smpboot.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86_64/kernel/smpboot.c')
-rw-r--r--arch/x86_64/kernel/smpboot.c120
1 files changed, 93 insertions, 27 deletions
diff --git a/arch/x86_64/kernel/smpboot.c b/arch/x86_64/kernel/smpboot.c
index e12d7baeb33e..683c33f7b967 100644
--- a/arch/x86_64/kernel/smpboot.c
+++ b/arch/x86_64/kernel/smpboot.c
@@ -64,9 +64,8 @@
int smp_num_siblings = 1;
/* Package ID of each logical CPU */
u8 phys_proc_id[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = BAD_APICID };
+/* core ID of each logical CPU */
u8 cpu_core_id[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = BAD_APICID };
-EXPORT_SYMBOL(phys_proc_id);
-EXPORT_SYMBOL(cpu_core_id);
/* Bitmask of currently online CPUs */
cpumask_t cpu_online_map __read_mostly;
@@ -89,7 +88,10 @@ struct cpuinfo_x86 cpu_data[NR_CPUS] __cacheline_aligned;
/* Set when the idlers are all forked */
int smp_threads_ready;
+/* representing HT siblings of each logical CPU */
cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly;
+
+/* representing HT and core siblings of each logical CPU */
cpumask_t cpu_core_map[NR_CPUS] __read_mostly;
EXPORT_SYMBOL(cpu_core_map);
@@ -436,30 +438,59 @@ void __cpuinit smp_callin(void)
cpu_set(cpuid, cpu_callin_map);
}
+/* representing cpus for which sibling maps can be computed */
+static cpumask_t cpu_sibling_setup_map;
+
static inline void set_cpu_sibling_map(int cpu)
{
int i;
+ struct cpuinfo_x86 *c = cpu_data;
+
+ cpu_set(cpu, cpu_sibling_setup_map);
if (smp_num_siblings > 1) {
- for_each_cpu(i) {
- if (cpu_core_id[cpu] == cpu_core_id[i]) {
+ for_each_cpu_mask(i, cpu_sibling_setup_map) {
+ if (phys_proc_id[cpu] == phys_proc_id[i] &&
+ cpu_core_id[cpu] == cpu_core_id[i]) {
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]);
}
}
} else {
cpu_set(cpu, cpu_sibling_map[cpu]);
}
- if (current_cpu_data.x86_num_cores > 1) {
- for_each_cpu(i) {
- if (phys_proc_id[cpu] == phys_proc_id[i]) {
- cpu_set(i, cpu_core_map[cpu]);
- cpu_set(cpu, cpu_core_map[i]);
- }
- }
- } else {
+ if (current_cpu_data.x86_max_cores == 1) {
cpu_core_map[cpu] = cpu_sibling_map[cpu];
+ c[cpu].booted_cores = 1;
+ return;
+ }
+
+ for_each_cpu_mask(i, cpu_sibling_setup_map) {
+ if (phys_proc_id[cpu] == phys_proc_id[i]) {
+ cpu_set(i, cpu_core_map[cpu]);
+ cpu_set(cpu, cpu_core_map[i]);
+ /*
+ * Does this new cpu bringup a new core?
+ */
+ if (cpus_weight(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)
+ c[cpu].booted_cores++;
+ /*
+ * increment the core count for all
+ * the other cpus in this package
+ */
+ if (i != cpu)
+ c[i].booted_cores++;
+ } else if (i != cpu && !c[cpu].booted_cores)
+ c[cpu].booted_cores = c[i].booted_cores;
+ }
}
}
@@ -474,6 +505,7 @@ void __cpuinit start_secondary(void)
* things done here to the most necessary things.
*/
cpu_init();
+ preempt_disable();
smp_callin();
/* otherwise gcc will move up the smp_processor_id before the cpu_init */
@@ -880,6 +912,9 @@ static __init void disable_smp(void)
}
#ifdef CONFIG_HOTPLUG_CPU
+
+int additional_cpus __initdata = -1;
+
/*
* cpu_possible_map should be static, it cannot change as cpu's
* are onlined, or offlined. The reason is per-cpu data-structures
@@ -888,14 +923,38 @@ static __init void disable_smp(void)
* cpu_present_map on the other hand can change dynamically.
* In case when cpu_hotplug is not compiled, then we resort to current
* behaviour, which is cpu_possible == cpu_present.
- * If cpu-hotplug is supported, then we need to preallocate for all
- * those NR_CPUS, hence cpu_possible_map represents entire NR_CPUS range.
* - Ashok Raj
+ *
+ * Three ways to find out the number of additional hotplug CPUs:
+ * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
+ * - otherwise use half of the available CPUs or 2, whatever is more.
+ * - The user can overwrite it with additional_cpus=NUM
+ * We do this because additional CPUs waste a lot of memory.
+ * -AK
*/
-static void prefill_possible_map(void)
+__init void prefill_possible_map(void)
{
int i;
- for (i = 0; i < NR_CPUS; i++)
+ int possible;
+
+ if (additional_cpus == -1) {
+ if (disabled_cpus > 0) {
+ additional_cpus = disabled_cpus;
+ } else {
+ additional_cpus = num_processors / 2;
+ if (additional_cpus == 0)
+ additional_cpus = 2;
+ }
+ }
+ possible = num_processors + additional_cpus;
+ if (possible > NR_CPUS)
+ possible = NR_CPUS;
+
+ printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n",
+ possible,
+ max_t(int, possible - num_processors, 0));
+
+ for (i = 0; i < possible; i++)
cpu_set(i, cpu_possible_map);
}
#endif
@@ -966,10 +1025,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
nmi_watchdog_default();
current_cpu_data = boot_cpu_data;
current_thread_info()->cpu = 0; /* needed? */
-
-#ifdef CONFIG_HOTPLUG_CPU
- prefill_possible_map();
-#endif
+ set_cpu_sibling_map(0);
if (smp_sanity_check(max_cpus) < 0) {
printk(KERN_INFO "SMP disabled\n");
@@ -1013,8 +1069,6 @@ void __init smp_prepare_boot_cpu(void)
int me = smp_processor_id();
cpu_set(me, cpu_online_map);
cpu_set(me, cpu_callout_map);
- cpu_set(0, cpu_sibling_map[0]);
- cpu_set(0, cpu_core_map[0]);
per_cpu(cpu_state, me) = CPU_ONLINE;
}
@@ -1067,9 +1121,6 @@ int __cpuinit __cpu_up(unsigned int cpu)
*/
void __init smp_cpus_done(unsigned int max_cpus)
{
-#ifndef CONFIG_HOTPLUG_CPU
- zap_low_mappings();
-#endif
smp_cleanup_boot();
#ifdef CONFIG_X86_IO_APIC
@@ -1086,15 +1137,24 @@ void __init smp_cpus_done(unsigned int max_cpus)
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]);
+ /*
+ * last thread sibling in this cpu core going down
+ */
+ if (cpus_weight(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]);
- for_each_cpu_mask(sibling, cpu_core_map[cpu])
- cpu_clear(cpu, cpu_core_map[sibling]);
cpus_clear(cpu_sibling_map[cpu]);
cpus_clear(cpu_core_map[cpu]);
phys_proc_id[cpu] = BAD_APICID;
cpu_core_id[cpu] = BAD_APICID;
+ cpu_clear(cpu, cpu_sibling_setup_map);
}
void remove_cpu_from_maps(void)
@@ -1158,6 +1218,12 @@ void __cpu_die(unsigned int cpu)
printk(KERN_ERR "CPU %u didn't die...\n", cpu);
}
+static __init int setup_additional_cpus(char *s)
+{
+ return get_option(&s, &additional_cpus);
+}
+__setup("additional_cpus=", setup_additional_cpus);
+
#else /* ... !CONFIG_HOTPLUG_CPU */
int __cpu_disable(void)
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-29 13:28:58 +0100