Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Thu, 11 Nov 2010 17:36:22 +0900 | From | MyungJoo Ham <> | Subject | [RFC-PATCH] clocksource: update lpj if clocksource has been changed. |
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With a clocksource change, loops_per_jiffy may have been changed; thus, the loops_per_jiffy in each cpu should be updated. Especially after some of the cpus were turned off and on, their loops_per_jiffy values are updated while the cpus kept on are not. Therefore, in order to make them "normalized equally", we need to let the loops_per_jiffy values of different cpus be based on the same clocksource.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> --- kernel/time/clocksource.c | 13 +++++++++++++ 1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index c18d7ef..a9d7935 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -30,6 +30,9 @@ #include <linux/sched.h> /* for spin_unlock_irq() using preempt_count() m68k */ #include <linux/tick.h> #include <linux/kthread.h> +#include <linux/delay.h> void timecounter_init(struct timecounter *tc, const struct cyclecounter *cc, @@ -592,6 +593,9 @@ static inline void clocksource_select(void) { } */ static int __init clocksource_done_booting(void) { +#ifdef CONFIG_SMP + int cpu; +#endif mutex_lock(&clocksource_mutex); curr_clocksource = clocksource_default_clock(); mutex_unlock(&clocksource_mutex); @@ -606,6 +610,13 @@ static int __init clocksource_done_booting(void) mutex_lock(&clocksource_mutex); clocksource_select(); mutex_unlock(&clocksource_mutex); + + calibrate_delay(); +#ifdef CONFIG_SMP + /* loops_per_jiffy may have been changed. */ + for_each_online_cpu(cpu) + smp_store_cpu_info(cpu); +#endif return 0; } fs_initcall(clocksource_done_booting); -- 1.6.3.3
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