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authorJack Steiner <steiner@sgi.com>2007-03-27 15:30:19 -0400
committerTony Luck <tony.luck@intel.com>2007-03-29 18:17:11 -0400
commitead6caae1e52a982bf09137c9b5382e9e2d52fdb (patch)
tree2aa16852ac080814f7fd1684c57e2cf594fc6ffe /arch/ia64/kernel/smpboot.c
parent83d2cd3de48a7fb73838c45145780cfa9b1f61fd (diff)
[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>
Diffstat (limited to 'arch/ia64/kernel/smpboot.c')
-rw-r--r--arch/ia64/kernel/smpboot.c17
1 files changed, 16 insertions, 1 deletions
diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c
index b21ddecea943..ff7df439da6d 100644
--- a/arch/ia64/kernel/smpboot.c
+++ b/arch/ia64/kernel/smpboot.c
@@ -375,6 +375,7 @@ static void __devinit
375smp_callin (void) 375smp_callin (void)
376{ 376{
377 int cpuid, phys_id, itc_master; 377 int cpuid, phys_id, itc_master;
378 struct cpuinfo_ia64 *last_cpuinfo, *this_cpuinfo;
378 extern void ia64_init_itm(void); 379 extern void ia64_init_itm(void);
379 extern volatile int time_keeper_id; 380 extern volatile int time_keeper_id;
380 381
@@ -424,7 +425,21 @@ smp_callin (void)
424 * Get our bogomips. 425 * Get our bogomips.
425 */ 426 */
426 ia64_init_itm(); 427 ia64_init_itm();
427 calibrate_delay(); 428
429 /*
430 * Delay calibration can be skipped if new processor is identical to the
431 * previous processor.
432 */
433 last_cpuinfo = cpu_data(cpuid - 1);
434 this_cpuinfo = local_cpu_data;
435 if (last_cpuinfo->itc_freq != this_cpuinfo->itc_freq ||
436 last_cpuinfo->proc_freq != this_cpuinfo->proc_freq ||
437 last_cpuinfo->features != this_cpuinfo->features ||
438 last_cpuinfo->revision != this_cpuinfo->revision ||
439 last_cpuinfo->family != this_cpuinfo->family ||
440 last_cpuinfo->archrev != this_cpuinfo->archrev ||
441 last_cpuinfo->model != this_cpuinfo->model)
442 calibrate_delay();
428 local_cpu_data->loops_per_jiffy = loops_per_jiffy; 443 local_cpu_data->loops_per_jiffy = loops_per_jiffy;
429 444
430#ifdef CONFIG_IA32_SUPPORT 445#ifdef CONFIG_IA32_SUPPORT