Messages in this thread Patch in this message | | | Date | Mon, 11 Jan 2010 18:48:02 -0800 | From | Yinghai Lu <> | Subject | [RFC PATCH 4/4] x86: according to nr_cpu_ids to decide if need to leave logical flat |
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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.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
--- arch/x86/kernel/apic/probe_32.c | 20 ++++++++++++++++++-- arch/x86/kernel/apic/probe_64.c | 3 ++- arch/x86/kernel/smpboot.c | 2 -- 3 files changed, 20 insertions(+), 5 deletions(-)
Index: linux-2.6/arch/x86/kernel/apic/probe_32.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/apic/probe_32.c +++ linux-2.6/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, @@ -207,6 +207,22 @@ void __init generic_bigsmp_probe(void) apic = &apic_bigsmp; printk(KERN_INFO "Overriding APIC driver with %s\n", apic->name); + } + } +#endif +} + +void 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 Index: linux-2.6/arch/x86/kernel/smpboot.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/smpboot.c +++ linux-2.6/arch/x86/kernel/smpboot.c @@ -1084,9 +1084,7 @@ void __init native_smp_prepare_cpus(unsi 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"); Index: linux-2.6/arch/x86/kernel/apic/probe_64.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/apic/probe_64.c +++ linux-2.6/arch/x86/kernel/apic/probe_64.c @@ -67,7 +67,8 @@ void __init default_setup_apic_routing(v } #endif - if (apic == &apic_flat && num_processors > 8) + /* not just num_processors, we could have hotplug cpus */ + if (apic == &apic_flat && nr_cpu_ids > 8) apic = &apic_physflat; printk(KERN_INFO "Setting APIC routing to %s\n", apic->name);
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