From ead6caae1e52a982bf09137c9b5382e9e2d52fdb Mon Sep 17 00:00:00 2001 From: Jack Steiner Date: Tue, 27 Mar 2007 14:30:19 -0500 Subject: [PATCH] [IA64] Speed up boot - skip unnecessary clock calibration 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 Signed-off-by: Tony Luck --- arch/ia64/kernel/smpboot.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c index b21ddecea9..ff7df439da 100644 --- a/arch/ia64/kernel/smpboot.c +++ b/arch/ia64/kernel/smpboot.c @@ -375,6 +375,7 @@ static void __devinit smp_callin (void) { int cpuid, phys_id, itc_master; + struct cpuinfo_ia64 *last_cpuinfo, *this_cpuinfo; extern void ia64_init_itm(void); extern volatile int time_keeper_id; @@ -424,7 +425,21 @@ 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. + */ + last_cpuinfo = cpu_data(cpuid - 1); + this_cpuinfo = local_cpu_data; + if (last_cpuinfo->itc_freq != this_cpuinfo->itc_freq || + last_cpuinfo->proc_freq != this_cpuinfo->proc_freq || + last_cpuinfo->features != this_cpuinfo->features || + last_cpuinfo->revision != this_cpuinfo->revision || + last_cpuinfo->family != this_cpuinfo->family || + last_cpuinfo->archrev != this_cpuinfo->archrev || + last_cpuinfo->model != this_cpuinfo->model) + calibrate_delay(); local_cpu_data->loops_per_jiffy = loops_per_jiffy; #ifdef CONFIG_IA32_SUPPORT -- 2.39.5