[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 <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c
index b21ddec..ff7df439 100644
--- a/arch/ia64/kernel/smpboot.c
+++ b/arch/ia64/kernel/smpboot.c
@@ -375,6 +375,7 @@
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 @@
* 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
