From: "Andi Kleen" Hack to disable clustered mode on AMD systems Make sure AMD big flat apic mode is not confused with clustered APIC mode. Ugly hack, but no better way found. Signed-off-by: Andi Kleen Signed-off-by: Andrew Morton --- 25-akpm/arch/x86_64/kernel/genapic.c | 7 +++++++ 1 files changed, 7 insertions(+) diff -puN arch/x86_64/kernel/genapic.c~x86_64-hack-to-disable-clustered-mode-on-amd-systems arch/x86_64/kernel/genapic.c --- 25/arch/x86_64/kernel/genapic.c~x86_64-hack-to-disable-clustered-mode-on-amd-systems 2005-01-09 23:01:14.249216896 -0800 +++ 25-akpm/arch/x86_64/kernel/genapic.c 2005-01-09 23:01:14.252216440 -0800 @@ -41,6 +41,12 @@ void __init clustered_apic_check(void) u8 id; u8 cluster_cnt[NUM_APIC_CLUSTERS]; + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) { + /* AMD always uses flat mode right now */ + genapic = &apic_flat; + goto print; + } + memset(cluster_cnt, 0, sizeof(cluster_cnt)); for (i = 0; i < NR_CPUS; i++) { @@ -71,6 +77,7 @@ void __init clustered_apic_check(void) else genapic = &apic_cluster; +print: printk(KERN_INFO "Setting APIC routing to %s\n", genapic->name); } _