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Commit a58f03b0 authored by Yinghai Lu's avatar Yinghai Lu Committed by Ingo Molnar
Browse files

x86: check bigsmp in smp_sanity_check instead of cpu_up 



clear bits for cpu nr > 8.

This allows us to boot the full range of possible CPUs that the
supported APIC model will allow. Previously we'd hang or boot up
with less than 8 CPUs.

Signed-off-by: default avatarYinghai Lu <yhlu.kernel@gmail.com>
Tested-by: default avatarJeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 858f7747

arch/x86/kernel/smpboot.c

+28 −10
Original line number Diff line number Diff line
@@ -994,17 +994,7 @@ int __cpuinit native_cpu_up(unsigned int cpu) 
	flush_tlb_all();

	low_mappings = 1;



#ifdef CONFIG_X86_PC

	if (def_to_bigsmp && apicid > 8) {

		printk(KERN_WARNING

			"More than 8 CPUs detected - skipping them.\n"

			"Use CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP.\n");

		err = -1;

	} else

		err = do_boot_cpu(apicid, cpu);

#else

	err = do_boot_cpu(apicid, cpu);

#endif



	zap_low_mappings();

	low_mappings = 0;
@@ -1058,6 +1048,34 @@ static __init void disable_smp(void) 
static int __init smp_sanity_check(unsigned max_cpus)

{

	preempt_disable();



#if defined(CONFIG_X86_PC) && defined(CONFIG_X86_32)

	if (def_to_bigsmp && nr_cpu_ids > 8) {

		unsigned int cpu;

		unsigned nr;



		printk(KERN_WARNING

		       "More than 8 CPUs detected - skipping them.\n"

		       "Use CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP.\n");



		nr = 0;

		for_each_present_cpu(cpu) {

			if (nr >= 8)

				cpu_clear(cpu, cpu_present_map);

			nr++;

		}



		nr = 0;

		for_each_possible_cpu(cpu) {

			if (nr >= 8)

				cpu_clear(cpu, cpu_possible_map);

			nr++;

		}



		nr_cpu_ids = 8;

	}

#endif



	if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) {

		printk(KERN_WARNING "weird, boot CPU (#%d) not listed"

				    "by the BIOS.\n", hard_smp_processor_id());