[PATCH 34/36] x86: according to nr_cpu_ids to decide if need to leave logical flat

Yinghai Lu
2010-01-21T06:31:19Z

should use nr_cpu_ids instead of num_processor, in case we have hotplug cpus.

if current only have 8 cpus is up, but if we will have more cpus that
will be hot added later, we should use physical flat at first.

nr_cpu_ids is the total cpus that could be supported.

-v2: per linus, chenage default_setup_apic_routing to _init, and call it for uni_processor

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
arch/x86/kernel/apic/apic.c | 2 --
arch/x86/kernel/apic/probe_32.c | 20 ++++++++++++++++++--
arch/x86/kernel/apic/probe_64.c | 6 +++++-
arch/x86/kernel/smpboot.c | 2 --
4 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 3987e44..3f2bfb1 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1641,9 +1641,7 @@ int __init APIC_init_uniprocessor(void)
#endif

enable_IR_x2apic();
-#ifdef CONFIG_X86_64
default_setup_apic_routing();
-#endif

verify_local_APIC();
connect_bsp_APIC();
diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c
index 1a6559f..d657558 100644
--- a/arch/x86/kernel/apic/probe_32.c
+++ b/arch/x86/kernel/apic/probe_32.c
@@ -52,7 +52,7 @@ static int __init print_ipi_mode(void)
}
late_initcall(print_ipi_mode);

-void default_setup_apic_routing(void)
+static void local_default_setup_apic_routing(void)
{
#ifdef CONFIG_X86_IO_APIC
printk(KERN_INFO
@@ -103,7 +103,7 @@ struct apic apic_default = {
.init_apic_ldr = default_init_apic_ldr,

.ioapic_phys_id_map = default_ioapic_phys_id_map,
- .setup_apic_routing = default_setup_apic_routing,
+ .setup_apic_routing = local_default_setup_apic_routing,
.multi_timer_check = NULL,
.apicid_to_node = default_apicid_to_node,
.cpu_to_logical_apicid = default_cpu_to_logical_apicid,
@@ -212,6 +212,22 @@ void __init generic_bigsmp_probe(void)
#endif
}

+void __init default_setup_apic_routing(void)
+{
+#ifdef CONFIG_X86_BIGSMP
+ /*
+ * make sure we go to bigsmp according to real nr_cpu_ids
+ */
+ if (!cmdline_apic && apic == &apic_default) {
+ if (nr_cpu_ids > 8) {
+ apic = &apic_bigsmp;
+ printk(KERN_INFO "Overriding APIC driver with %s\n",
+ apic->name);
+ }
+ }
+#endif
+}
+
void __init generic_apic_probe(void)
{
if (!cmdline_apic) {
diff --git a/arch/x86/kernel/apic/probe_64.c b/arch/x86/kernel/apic/probe_64.c
index 450fe20..7dce6f9 100644
--- a/arch/x86/kernel/apic/probe_64.c
+++ b/arch/x86/kernel/apic/probe_64.c
@@ -67,7 +67,11 @@ void __init default_setup_apic_routing(void)
}
#endif

- if (apic == &apic_flat && num_processors > 8)
+ /*
+ * not just num_processors, we could have hotplug cpus plugged
+ * in later
+ */
+ if (apic == &apic_flat && nr_cpu_ids > 8)
apic = &apic_physflat;

printk(KERN_INFO "Setting APIC routing to %s\n", apic->name);
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index eff2fe1..96f5f40 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1083,9 +1083,7 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
set_cpu_sibling_map(0);

enable_IR_x2apic();
-#ifdef CONFIG_X86_64
default_setup_apic_routing();
-#endif

if (smp_sanity_check(max_cpus) < 0) {
printk(KERN_INFO "SMP disabled\n");
--
1.6.4.2