[PATCH] MIPS: Add sched_clock() to csrc-octeon.c

[PATCH] MIPS: Add sched_clock() to csrc-octeon.c

[David Daney]

With the advent of function graph tracing on MIPS, Octeon needs a high
precision sched_clock() implementation.  Without it, most timing
numbers are reported as 0.000.

This new sched_clock just uses the 64-bit cycle counter appropriately
scaled.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
---
 arch/mips/cavium-octeon/csrc-octeon.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/arch/mips/cavium-octeon/csrc-octeon.c b/arch/mips/cavium-octeon/csrc-octeon.c
index 96110f2..96df821 100644
--- a/arch/mips/cavium-octeon/csrc-octeon.c
+++ b/arch/mips/cavium-octeon/csrc-octeon.c
@@ -50,6 +50,13 @@ static struct clocksource clocksource_mips = {
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
+unsigned long long notrace sched_clock(void)
+{
+	return clocksource_cyc2ns(read_c0_cvmcount(),
+				  clocksource_mips.mult,
+				  clocksource_mips.shift);
+}
+
 void __init plat_time_init(void)
 {
 	clocksource_mips.rating = 300;
-- 
1.6.0.6

Re: [PATCH] MIPS: Add sched_clock() to csrc-octeon.c

[Ralf Baechle]

On Wed, Dec 23, 2009 at 01:18:54PM -0800, David Daney wrote:

> With the advent of function graph tracing on MIPS, Octeon needs a high
> precision sched_clock() implementation.  Without it, most timing
> numbers are reported as 0.000.
> 
> This new sched_clock just uses the 64-bit cycle counter appropriately
> scaled.

Thanks, applied!

  Ralf