From fc9069fe56d9594b7a6da0b9f9ca0eafd756260f Mon Sep 17 00:00:00 2001 From: Tony Breeds Date: Wed, 4 Jul 2007 14:04:31 +1000 Subject: [POWERPC] Modify sched_clock() to make CONFIG_PRINTK_TIME more sane 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 measure. Signed-off-by: Tony Breeds Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/time.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'arch/powerpc') diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 66d2db7495a..e5df167f782 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -112,8 +112,9 @@ 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; @@ -755,7 +756,7 @@ 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) @@ -974,6 +975,8 @@ 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(); -- cgit v1.2.3-18-g5258