Commit e17ba8f5 authored Sep 23, 2006 by David S. Miller Committed by David S. Miller Sep 23, 2006

[SPARC64]: Fix sched_clock() wrapping every ~17 seconds.



Unfortunately, sparc64 doesn't have an easy way to do a "64 X 64 -->
128" bit multiply like PowerPC and IA64 do.  We were doing a
"64 X 64 --> 64" bit multiple which causes overflow very quickly with
a 30-bit quotient shift.

So use a quotientshift count of 10 instead of 30, just like x86 and
ARM do.

This also fixes the wrapping of printk timestamp values every ~17
seconds.

Signed-off-by: David S. Miller <davem@davemloft.net>

parent 1ab9dd09

arch/sparc64/kernel/time.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -983,7 +983,7 @@ static struct time_interpolator sparc64_cpu_interpolator = {
		};

		/* The quotient formula is taken from the IA64 port. */
		#define SPARC64_NSEC_PER_CYC_SHIFT 30UL
		#define SPARC64_NSEC_PER_CYC_SHIFT 10UL
		void __init time_init(void)
		{
		unsigned long clock = sparc64_init_timers();