Skip clock calibration if cpu being brought online is exactly the same speed, stepping, etc., as the previous cpu. This significantly reduces the time to boot very large systems. Signed-off-by: Jack Steiner <steiner@xxxxxxx> Index: linux/arch/ia64/kernel/smpboot.c =================================================================== --- linux.orig/arch/ia64/kernel/smpboot.c 2007-03-26 15:04:29.322256475 -0500 +++ linux/arch/ia64/kernel/smpboot.c 2007-03-27 08:26:41.914042190 -0500 @@ -424,7 +424,19 @@ smp_callin (void) * Get our bogomips. */ ia64_init_itm(); - calibrate_delay(); + + /* + * Delay calibration can be skipped if new processor is identical to the + * previous processor. + */ + if (local_cpu_data->itc_freq != per_cpu(cpu_info, cpuid - 1).itc_freq || + local_cpu_data->proc_freq != per_cpu(cpu_info, cpuid - 1).proc_freq || + local_cpu_data->features != per_cpu(cpu_info, cpuid - 1).features || + local_cpu_data->revision != per_cpu(cpu_info, cpuid - 1).revision || + local_cpu_data->family != per_cpu(cpu_info, cpuid - 1).family || + local_cpu_data->archrev != per_cpu(cpu_info, cpuid - 1).archrev || + local_cpu_data->model != per_cpu(cpu_info, cpuid - 1).model) + calibrate_delay(); local_cpu_data->loops_per_jiffy = loops_per_jiffy; #ifdef CONFIG_IA32_SUPPORT - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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