linux/kernel/time
Frederic Weisbecker 2ac0d98fd6 nohz: Make nohz API agnostic against idle ticks cputime accounting
When the timer tick fires, it accounts the new jiffy as either part
of system, user or idle time. This is how we record the cputime
statistics.

But when the tick is stopped from the idle task, we still need
to record the number of jiffies spent tickless until we restart
the tick and fall back to traditional tick-based cputime accounting.

To do this, we take a snapshot of jiffies when the tick is stopped
and compute the difference against the new value of jiffies when
the tick is restarted. Then we account this whole difference to
the idle cputime.

However we are preparing to be able to stop the tick from other places
than idle. So this idle time accounting needs to be performed from
the callers of nohz APIs, not from the nohz APIs themselves because
we now want them to be agnostic against places that stop/restart tick.

Therefore, we pull the tickless idle time accounting out of generic
nohz helpers up to idle entry/exit callers.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
2012-06-11 20:07:16 +02:00
..
alarmtimer.c alarmtimer: Provide accessor to alarmtimer rtc device 2012-04-20 14:56:36 -07:00
clockevents.c clockevents: Make clockevents_config() a global symbol 2012-05-25 01:44:51 +02:00
clocksource.c kernel-time: fix s/then/than/ spelling errors 2012-03-23 16:49:21 -07:00
jiffies.c Fix common misspellings 2011-03-31 11:26:23 -03:00
Kconfig timers: Fixup the Kconfig consolidation fallout 2012-05-21 23:43:46 +02:00
Makefile timers: Introduce in-kernel alarm-timer interface 2011-04-26 14:01:44 -07:00
ntp.c ntp: Fix a stale comment and a few stray newlines. 2012-05-21 16:16:56 -07:00
posix-clock.c kernel: Fix files explicitly needing EXPORT_SYMBOL infrastructure 2011-10-31 19:30:05 -04:00
tick-broadcast.c tick: Fix the spurious broadcast timer ticks after resume 2012-04-19 21:27:50 +02:00
tick-common.c clockevents: Make minimum delay adjustments configurable 2011-09-08 11:10:56 +02:00
tick-internal.h clockevents: Make minimum delay adjustments configurable 2011-09-08 11:10:56 +02:00
tick-oneshot.c clockevents: Make minimum delay adjustments configurable 2011-09-08 11:10:56 +02:00
tick-sched.c nohz: Make nohz API agnostic against idle ticks cputime accounting 2012-06-11 20:07:16 +02:00
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 timekeeping: Fix CLOCK_MONOTONIC inconsistency during leapsecond 2012-06-04 21:46:29 +02:00
timer_list.c timer debug: Hide kernel addresses via %pK in /proc/timer_list 2011-02-12 14:11:56 +01:00
timer_stats.c locking, timer_stats: Annotate table_lock as raw 2011-09-13 11:12:00 +02:00