linux.git/kernel/time/tick-sched.c, branch v3.15.1

tick-sched: Check tick_nohz_enabled in tick_nohz_switch_to_nohz()

2014-04-15T18:26:58+00:00

Since commit d689fe222 (NOHZ: Check for nohz active instead of nohz
enabled) the tick_nohz_switch_to_nohz() function returns because it
checks for the tick_nohz_active flag. This can't be set, because the
function itself sets it.

Undo the change in tick_nohz_switch_to_nohz().

Signed-off-by: Viresh Kumar 
Cc: linaro-kernel@lists.linaro.org
Cc: fweisbec@gmail.com
Cc: Arvind.Chauhan@arm.com
Cc: linaro-networking@linaro.org
Cc:  # 3.13+
Link: http://lkml.kernel.org/r/40939c05f2d65d781b92b20302b02243d0654224.1397537987.git.viresh.kumar@linaro.org
Signed-off-by: Thomas Gleixner

tick-sched: Don't call update_wall_time() when delta is lesser than tick_period

2014-04-15T18:26:45+00:00

In tick_do_update_jiffies64() we are processing ticks only if delta is
greater than tick_period. This is what we are supposed to do here and
it broke a bit with this patch:

commit 47a1b796 (tick/timekeeping: Call update_wall_time outside the
jiffies lock)

With above patch, we might end up calling update_wall_time() even if
delta is found to be smaller that tick_period. Fix this by returning
when the delta is less than tick period.

[ tglx: Made it a 3 liner and massaged changelog ]

Signed-off-by: Viresh Kumar 
Cc: linaro-kernel@lists.linaro.org
Cc: fweisbec@gmail.com
Cc: Arvind.Chauhan@arm.com
Cc: linaro-networking@linaro.org
Cc: John Stultz 
Cc:  # v3.14+
Link: http://lkml.kernel.org/r/80afb18a494b0bd9710975bcc4de134ae323c74f.1397537987.git.viresh.kumar@linaro.org
Signed-off-by: Thomas Gleixner

Merge branch 'timers/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/urgent

2014-01-25T07:27:26+00:00

Pull dynticks cleanups from Frederic Weisbecker.

Signed-off-by: Ingo Molnar

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-01-20T19:34:26+00:00

Pull timer changes from Ingo Molnar:
  - ARM clocksource/clockevent improvements and fixes
  - generic timekeeping updates: TAI fixes/improvements, cleanups
  - Posix cpu timer cleanups and improvements
  - dynticks updates: full dynticks bugfixes, optimizations and cleanups

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits)
  clocksource: Timer-sun5i: Switch to sched_clock_register()
  timekeeping: Remove comment that's mostly out of date
  rtc-cmos: Add an alarm disable quirk
  timekeeper: fix comment typo for tk_setup_internals()
  timekeeping: Fix missing timekeeping_update in suspend path
  timekeeping: Fix CLOCK_TAI timer/nanosleep delays
  tick/timekeeping: Call update_wall_time outside the jiffies lock
  timekeeping: Avoid possible deadlock from clock_was_set_delayed
  timekeeping: Fix potential lost pv notification of time change
  timekeeping: Fix lost updates to tai adjustment
  clocksource: sh_cmt: Add clk_prepare/unprepare support
  clocksource: bcm_kona_timer: Remove unused bcm_timer_ids
  clocksource: vt8500: Remove deprecated IRQF_DISABLED
  clocksource: tegra: Remove deprecated IRQF_DISABLED
  clocksource: misc drivers: Remove deprecated IRQF_DISABLED
  clocksource: sh_mtu2: Remove unnecessary platform_set_drvdata()
  clocksource: sh_tmu: Remove unnecessary platform_set_drvdata()
  clocksource: armada-370-xp: Enable timer divider only when needed
  clocksource: clksrc-of: Warn if no clock sources are found
  clocksource: orion: Switch to sched_clock_register()
  ...

nohz_full: fix code style issue of tick_nohz_full_stop_tick

2014-01-15T22:07:11+00:00

Code usually starts with 'tab' instead of 7 'space' in kernel

Signed-off-by: Alex Shi 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Alex Shi 
Cc: Steven Rostedt 
Cc: Paul E. McKenney 
Cc: John Stultz 
Cc: Kevin Hilman 
Link: http://lkml.kernel.org/r/1386074112-30754-2-git-send-email-alex.shi@linaro.org
Signed-off-by: Frederic Weisbecker

nohz: Get timekeeping max deferment outside jiffies_lock

2014-01-15T22:07:11+00:00

We don't need to fetch the timekeeping max deferment under the
jiffies_lock seqlock.

If the clocksource is updated concurrently while we stop the tick,
stop machine is called and the tick will be reevaluated again along with
uptodate jiffies and its related values.

Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Alex Shi 
Cc: Steven Rostedt 
Cc: Paul E. McKenney 
Cc: John Stultz 
Cc: Kevin Hilman 
Link: http://lkml.kernel.org/r/1387320692-28460-9-git-send-email-fweisbec@gmail.com
Signed-off-by: Frederic Weisbecker

tick: Rename tick_check_idle() to tick_irq_enter()

2014-01-15T22:05:31+00:00

This makes the code more symetric against the existing tick functions
called on irq exit: tick_irq_exit() and tick_nohz_irq_exit().

These function are also symetric as they mirror each other's action:
we start to account idle time on irq exit and we stop this accounting
on irq entry. Also the tick is stopped on irq exit and timekeeping
catches up with the tickless time elapsed until we reach irq entry.

This rename was suggested by Peter Zijlstra a long while ago but it
got forgotten in the mass.

Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Alex Shi 
Cc: Steven Rostedt 
Cc: Paul E. McKenney 
Cc: John Stultz 
Cc: Kevin Hilman 
Link: http://lkml.kernel.org/r/1387320692-28460-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Frederic Weisbecker

sched/clock, x86: Use a static_key for sched_clock_stable

2014-01-13T14:13:13+00:00

In order to avoid the runtime condition and variable load turn
sched_clock_stable into a static_key.

Also provide a shorter implementation of local_clock() and
cpu_clock(int) when sched_clock_stable==1.

                        MAINLINE   PRE       POST

    sched_clock_stable: 1          1         1
    (cold) sched_clock: 329841     221876    215295
    (cold) local_clock: 301773     234692    220773
    (warm) sched_clock: 38375      25602     25659
    (warm) local_clock: 100371     33265     27242
    (warm) rdtsc:       27340      24214     24208
    sched_clock_stable: 0          0         0
    (cold) sched_clock: 382634     235941    237019
    (cold) local_clock: 396890     297017    294819
    (warm) sched_clock: 38194      25233     25609
    (warm) local_clock: 143452     71234     71232
    (warm) rdtsc:       27345      24245     24243

Signed-off-by: Peter Zijlstra 
Cc: Linus Torvalds 
Cc: Andrew Morton 
Link: http://lkml.kernel.org/n/tip-eummbdechzz37mwmpags1gjr@git.kernel.org
Signed-off-by: Ingo Molnar

Merge branch 'fortglx/3.14/time' of git://git.linaro.org/people/john.stultz/linux into timers/core

2014-01-12T13:13:31+00:00

Pull timekeeping updates from John Stultz.

Signed-off-by: Ingo Molnar

Merge branch 'linus' into timers/core

2014-01-12T13:12:44+00:00

Pick up the latest fixes and refresh the branch.

Signed-off-by: Ingo Molnar