linux/kernel/time
John Stultz 1aa5dfb751 clocksource: keep track of original clocksource frequency
The clocksource frequency is represented by
clocksource->mult/2^(clocksource->shift).  Currently, when NTP makes
adjustments to the clock frequency, they are made directly to the mult
value.

This has the drawback that once changed, we cannot know what the orignal
mult value was, or how much adjustment has been applied.

This property causes problems in calculating proper ntp intervals when
switching back and forth between clocksources.

This patch separates the current mult value into a mult and mult_orig
pair.  The mult_orig value stays constant, while the ntp clocksource
adjustments are done only to the mult value.

This allows for correct ntp interval calculation and additionally lays the
groundwork for a new notion of time, what I'm calling the monotonic-raw
time, which is introduced in a following patch.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-21 09:50:23 +02:00
..
clockevents.c time: fix typo in comments 2008-02-08 09:22:29 -08:00
clocksource.c clocksource: keep track of original clocksource frequency 2008-08-21 09:50:23 +02:00
jiffies.c clocksource: keep track of original clocksource frequency 2008-08-21 09:50:23 +02:00
Kconfig clockevents: Allow build w/o run-tine usage for migration purposes 2007-10-12 23:04:05 +02:00
Makefile clockevents: Allow build w/o run-tine usage for migration purposes 2007-10-12 23:04:05 +02:00
ntp.c ntp: handle leap second via timer 2008-05-01 08:03:59 -07:00
tick-broadcast.c Merge branch 'linus' into cpus4096 2008-07-16 00:29:07 +02:00
tick-common.c cpumask: change cpumask_of_cpu_ptr to use new cpumask_of_cpu 2008-07-26 16:40:33 +02:00
tick-internal.h timer: clean up tick-broadcast.c 2008-01-30 13:30:01 +01:00
tick-oneshot.c [S390] genirq/clockevents: move irq affinity prototypes/inlines to interrupt.h 2008-04-17 07:47:05 +02:00
tick-sched.c sched clock: revert various sched_clock() changes 2008-07-31 17:20:29 +02:00
timekeeping.c ntp: handle leap second via timer 2008-05-01 08:03:59 -07:00
timer_list.c kernel: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00
timer_stats.c kernel: use non-racy method for proc entries creation 2008-04-29 08:06:22 -07:00