From: Hans-Frieder Vogt I traced the current double-speed issue for 2.6.7-bk2 on x86-64 back to an ACPI-change in mpparse.c. The small attached patch solved the issue at least on my MSI K8T Neo (Athlon 64 3200+) system. Signed-off-by: Andrew Morton --- 25-akpm/arch/x86_64/kernel/mpparse.c | 2 +- 1 files changed, 1 insertion(+), 1 deletion(-) diff -puN arch/x86_64/kernel/mpparse.c~x86_64-double-clock-speed-fix arch/x86_64/kernel/mpparse.c --- 25/arch/x86_64/kernel/mpparse.c~x86_64-double-clock-speed-fix 2004-06-20 14:39:45.657103608 -0700 +++ 25-akpm/arch/x86_64/kernel/mpparse.c 2004-06-20 14:39:45.661103000 -0700 @@ -861,7 +861,7 @@ void __init mp_config_acpi_legacy_irqs ( for (idx = 0; idx < mp_irq_entries; idx++) if (mp_irqs[idx].mpc_srcbus == MP_ISA_BUS && - (mp_irqs[idx].mpc_dstapic == ioapic) && + (mp_irqs[idx].mpc_dstapic == intsrc.mpc_dstapic) && (mp_irqs[idx].mpc_srcbusirq == i || mp_irqs[idx].mpc_dstirq == i)) break; _