Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

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

[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

arch/ia64/kernel/smpboot.c

+16 −1
Original line number Diff line number Diff line
@@ -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;
@@ -424,6 +425,20 @@ smp_callin (void) 
	 * Get our bogomips.

	 */

	ia64_init_itm();



	/*

	 * 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;