kernel_optimize_test/kernel/time
Alexander Gordeev 025b40abe7 ntp: add hardpps implementation
This commit adds hardpps() implementation based upon the original one from
the NTPv4 reference kernel code from David Mills.  However, it is highly
optimized towards very fast syncronization and maximum stickness to PPS
signal.  The typical error is less then a microsecond.

To make it sync faster I had to throw away exponential phase filter so
that the full phase offset is corrected immediately.  Then I also had to
throw away median phase filter because it gives a bigger error itself if
used without exponential filter.

Maybe we will find an appropriate filtering scheme in the future but it's
not necessary if the signal quality is ok.

Signed-off-by: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 08:03:20 -08:00
..
clockevents.c clockevent: Don't remove broadcast device when cpu is dead 2010-01-18 14:44:50 +01:00
clocksource.c Fix rounding in clocks_calc_mult_shift() 2010-12-22 22:44:43 +00:00
jiffies.c clocksource: Cleanup clocksource selection 2009-08-15 10:55:46 +02:00
Kconfig time: Kill off CONFIG_GENERIC_TIME 2010-07-27 12:40:54 +02:00
Makefile time: add function to convert between calendar time and broken-down time for universal use 2009-09-24 07:20:56 -07:00
ntp.c ntp: add hardpps implementation 2011-01-13 08:03:20 -08:00
tick-broadcast.c fix comment/printk typos concerning "already" 2010-07-11 21:45:40 +02:00
tick-common.c core: Replace __get_cpu_var with __this_cpu_read if not used for an address. 2010-12-17 15:07:19 +01:00
tick-internal.h clockevents: Make tick_device_lock static 2009-12-14 23:55:34 +01:00
tick-oneshot.c core: Replace __get_cpu_var with __this_cpu_read if not used for an address. 2010-12-17 15:07:19 +01:00
tick-sched.c Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-08-06 13:12:36 -07:00
timecompare.c time: Use ARRAY_SIZE macro in timecompare.c 2010-10-21 17:30:06 +02:00
timeconv.c time: add function to convert between calendar time and broken-down time for universal use 2009-09-24 07:20:56 -07:00
timekeeping.c time: Compensate for rounding on odd-frequency clocksources 2010-10-21 17:30:05 +02:00
timer_list.c hrtimers: Convert hrtimers to use timerlist infrastructure 2010-12-10 11:54:35 -08:00
timer_stats.c hrtimers: Convert to raw_spinlocks 2009-12-14 23:55:34 +01:00