kernel_optimize_test/kernel/time
Thomas Gleixner 6d3aadf3e1 timekeeping: Restructure the timekeeper some more
Access to time requires to touch two cachelines at minimum

   1) The timekeeper data structure

   2) The clocksource data structure

The access to the clocksource data structure can be avoided as almost
all clocksource implementations ignore the argument to the read
callback, which is a pointer to the clocksource.

But the core needs to touch it to access the members @read and @mask.

So we are better off by copying the @read function pointer and the
@mask from the clocksource to the core data structure itself.

For the most used ktime_get() access all required data including the
@read and @mask copies fits together with the sequence counter into a
single 64 byte cacheline.

For the other time access functions we touch in the current code three
cache lines in the worst case. But with the clocksource data copies we
can reduce that to two adjacent cachelines, which is more efficient
than disjunct cache lines.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 15:01:52 -07:00
..
alarmtimer.c alarmtimer: return EINVAL instead of ENOTSUPP if rtcdev doesn't exist 2013-10-18 16:23:58 -07:00
clockevents.c time: Change the return type of clockevents_notify() to integer 2014-02-07 15:34:29 +01:00
clocksource.c clocksource: Make delta calculation a function 2014-07-23 15:01:51 -07:00
hrtimer.c time: Consolidate the time accessor prototypes 2014-07-23 10:17:54 -07:00
itimer.c time/timers: Move all time(r) related files into kernel/time 2014-06-23 11:22:35 +02:00
jiffies.c time: Fix overflow when HZ is smaller than 60 2014-02-06 16:01:40 +01:00
Kconfig clocksource: Move cycle_last validation to core code 2014-07-23 15:01:51 -07:00
Makefile kernel: time: Add udelay_test module to validate udelay 2014-07-23 10:16:35 -07:00
ntp_internal.h timekeeping: Convert timekeeping core to use timespec64s 2014-07-23 10:17:54 -07:00
ntp.c timekeeping: Provide timespec64 based interfaces 2014-07-23 10:17:55 -07:00
posix-clock.c
posix-cpu-timers.c time/timers: Move all time(r) related files into kernel/time 2014-06-23 11:22:35 +02:00
posix-timers.c time: Consolidate the time accessor prototypes 2014-07-23 10:17:54 -07:00
sched_clock.c sched_clock: Remove deprecated setup_sched_clock() API 2014-04-22 13:38:33 -07:00
tick-broadcast-hrtimer.c tick: Fixup more fallout from hrtimer broadcast mode 2014-02-09 15:11:47 +01:00
tick-broadcast.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-04-01 11:00:07 -07:00
tick-common.c tick-common: Fix wrong check in tick_check_replacement() 2014-04-15 20:26:44 +02:00
tick-internal.h time: Consolidate the time accessor prototypes 2014-07-23 10:17:54 -07:00
tick-oneshot.c
tick-sched.c tick-sched: Check tick_nohz_enabled in tick_nohz_switch_to_nohz() 2014-04-15 20:26:58 +02:00
time.c time: Export nsecs_to_jiffies() 2014-07-23 10:18:04 -07:00
timeconst.bc time/timers: Move all time(r) related files into kernel/time 2014-06-23 11:22:35 +02:00
timeconv.c
timekeeping_debug.c timekeeping: Convert timekeeping core to use timespec64s 2014-07-23 10:17:54 -07:00
timekeeping_internal.h clocksource: Move cycle_last validation to core code 2014-07-23 15:01:51 -07:00
timekeeping.c timekeeping: Restructure the timekeeper some more 2014-07-23 15:01:52 -07:00
timekeeping.h time: Consolidate the time accessor prototypes 2014-07-23 10:17:54 -07:00
timer_list.c timer_list: correct the iterator for timer_list 2013-08-28 19:26:38 -07:00
timer_stats.c timer stats: Add a 'Collection: active/inactive' line to timer usage statistics 2013-10-10 09:59:25 +02:00
timer.c timer: Kick dynticks targets on mod_timer*() calls 2014-06-23 11:23:47 +02:00
udelay_test.c kernel: time: Add udelay_test module to validate udelay 2014-07-23 10:16:35 -07:00