Commit ead6caae authored by Jack Steiner's avatar Jack Steiner Committed by Tony Luck

[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: default avatarJack Steiner <steiner@sgi.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent 83d2cd3d
...@@ -375,6 +375,7 @@ static void __devinit ...@@ -375,6 +375,7 @@ static void __devinit
smp_callin (void) smp_callin (void)
{ {
int cpuid, phys_id, itc_master; int cpuid, phys_id, itc_master;
struct cpuinfo_ia64 *last_cpuinfo, *this_cpuinfo;
extern void ia64_init_itm(void); extern void ia64_init_itm(void);
extern volatile int time_keeper_id; extern volatile int time_keeper_id;
...@@ -424,7 +425,21 @@ smp_callin (void) ...@@ -424,7 +425,21 @@ smp_callin (void)
* Get our bogomips. * Get our bogomips.
*/ */
ia64_init_itm(); 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; local_cpu_data->loops_per_jiffy = loops_per_jiffy;
#ifdef CONFIG_IA32_SUPPORT #ifdef CONFIG_IA32_SUPPORT
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment