Messages in this thread Patch in this message | | | Date | Fri, 29 Dec 2006 18:52:16 +0300 | From | Alexey Dobriyan <> | Subject | [RFC] Use jiffies_64 in sched_clock() |
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Would it make sense to always use jiffies_64 instead of jiffies? (module hardware specific version)
This is what FRV, UML, one ia64 version, one i386 version do.
Also substract initial jiffies.
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> ---
arch/frv/kernel/time.c | 8 -------- arch/um/kernel/time.c | 8 -------- kernel/sched.c | 3 ++- 3 files changed, 2 insertions(+), 17 deletions(-)
--- a/arch/frv/kernel/time.c +++ b/arch/frv/kernel/time.c @@ -139,11 +139,3 @@ void time_init(void) time_divisor_init(); } - -/* - * Scheduler clock - returns current time in nanosec units. - */ -unsigned long long sched_clock(void) -{ - return jiffies_64 * (1000000000 / HZ); -} --- a/arch/um/kernel/time.c +++ b/arch/um/kernel/time.c @@ -27,14 +27,6 @@ int hz(void) return(HZ); } -/* - * Scheduler clock - returns current time in nanosec units. - */ -unsigned long long sched_clock(void) -{ - return (unsigned long long)jiffies_64 * (1000000000 / HZ); -} - static unsigned long long prev_nsecs; #ifdef CONFIG_UML_REAL_TIME_CLOCK static long long delta; /* Deviation per interval */ --- a/kernel/sched.c +++ b/kernel/sched.c @@ -64,7 +64,8 @@ #include <asm/unistd.h> */ unsigned long long __attribute__((weak)) sched_clock(void) { - return (unsigned long long)jiffies * (1000000000 / HZ); + /* No locking but a rare wrong value is not a big deal. */ + return (jiffies_64 - INITIAL_JIFFIES) * (1000000000 / HZ); } /* - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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