When booting a current kernel with CONFIG_PRINTK_TIME enabled you'll
see messages like:
[ 0.000000] time_init: decrementer frequency = 188.044000 MHz
[ 0.000000] time_init: processor frequency = 1504.352000 MHz
[3712914.436297] Console: colour dummy device 80x25
This cause by the initialisation of tb_to_ns_scale in time_init(), suddenly the
multiplication in sched_clock() now does something :). This patch modifies
sched_clock() to report the offset since the machine booted so the same
printk's now look like:
[ 0.000000] time_init: decrementer frequency = 188.044000 MHz
[ 0.000000] time_init: processor frequency = 1504.352000 MHz
[ 0.000135] Console: colour dummy device 80x25
Effectivly including the uptime in printk()s.
This patch makes tb_to_ns_scale and tb_to_ns_shift static and read_mostly for
good meassure.
Signed-off-by: Tony Breeds <[EMAIL PROTECTED]>
---
There looks to be other variables that could be made static, I think
that's a job for another day though.
arch/powerpc/kernel/time.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
Index: working/arch/powerpc/kernel/time.c
===================================================================
--- working.orig/arch/powerpc/kernel/time.c
+++ working/arch/powerpc/kernel/time.c
@@ -113,8 +113,9 @@ u64 ticklen_to_xs; /* 0.64 fraction */
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL_GPL(rtc_lock);
-u64 tb_to_ns_scale;
-unsigned tb_to_ns_shift;
+static u64 tb_to_ns_scale __read_mostly;
+static unsigned tb_to_ns_shift __read_mostly;
+static unsigned long boot_tb __read_mostly;
struct gettimeofday_struct do_gtod;
@@ -735,7 +736,7 @@ unsigned long long sched_clock(void)
{
if (__USE_RTC())
return get_rtc();
- return mulhdu(get_tb(), tb_to_ns_scale) << tb_to_ns_shift;
+ return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
}
int do_settimeofday(struct timespec *tv)
@@ -960,6 +961,8 @@ void __init time_init(void)
}
tb_to_ns_scale = scale;
tb_to_ns_shift = shift;
+ /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
+ boot_tb = get_tb();
tm = get_boot_time();
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