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Marcelo Tosatti e0b306fef9 time: export time information for KVM pvclock
As suggested by John, export time data similarly to how its
done by vsyscall support. This allows KVM to retrieve necessary
information to implement vsyscall support in KVM guests.

Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27 23:29:12 -02:00
Linus Torvalds 03d3602a83 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer core update from Thomas Gleixner:
 - Bug fixes (one for a longstanding dead loop issue)
 - Rework of time related vsyscalls
 - Alarm timer updates
 - Jiffies updates to remove compile time dependencies

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping: Cast raw_interval to u64 to avoid shift overflow
  timers: Fix endless looping between cascade() and internal_add_timer()
  time/jiffies: bring back unconditional LATCH definition
  time: Convert x86_64 to using new update_vsyscall
  time: Only do nanosecond rounding on GENERIC_TIME_VSYSCALL_OLD systems
  time: Introduce new GENERIC_TIME_VSYSCALL
  time: Convert CONFIG_GENERIC_TIME_VSYSCALL to CONFIG_GENERIC_TIME_VSYSCALL_OLD
  time: Move update_vsyscall definitions to timekeeper_internal.h
  time: Move timekeeper structure to timekeeper_internal.h for vsyscall changes
  jiffies: Remove compile time assumptions about CLOCK_TICK_RATE
  jiffies: Kill unused TICK_USEC_TO_NSEC
  alarmtimer: Rename alarmtimer_remove to alarmtimer_dequeue
  alarmtimer: Remove unused helpers & defines
  alarmtimer: Use hrtimer per-alarm instead of per-base
  alarmtimer: Implement minimum alarm interval for allowing suspend
2012-10-12 22:17:48 +09:00
Linus Torvalds 0588f1f934 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "A CPU hotplug related crash fix and a nohz accounting fixlet."

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Update sched_domains_numa_masks[][] when new cpus are onlined
  sched: Ensure 'sched_domains_numa_levels' is safe to use in other functions
  nohz: Fix one jiffy count too far in idle cputime
2012-10-12 22:13:05 +09:00
Dan Carpenter 5b3900cd40 timekeeping: Cast raw_interval to u64 to avoid shift overflow
We fixed a bunch of integer overflows in timekeeping code during the 3.6
cycle.  I did an audit based on that and found this potential overflow.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Link: http://lkml.kernel.org/r/20121009071823.GA19159@elgon.mountain
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
2012-10-09 21:27:14 +02:00
Frederic Weisbecker 2b17c545a4 nohz: Fix one jiffy count too far in idle cputime
When we stop the tick in idle, we save the current jiffies value
in ts->idle_jiffies. This snapshot is substracted from the later
value of jiffies when the tick is restarted and the resulting
delta is accounted as idle cputime. This is how we handle the
idle cputime accounting without the tick.

But sometimes we need to schedule the next tick to some time in
the future instead of completely stopping it. In this case, a
tick may happen before we restart the periodic behaviour and
from that tick we account one jiffy to idle cputime as usual but
we also increment the ts->idle_jiffies snapshot by one so that
when we compute the delta to account, we substract the one jiffy
we just accounted.

To prepare for stopping the tick outside idle, we introduced a
check that prevents from fixing up that ts->idle_jiffies if we
are not running the idle task. But we use idle_cpu() for that
and this is a problem if we run the tick while another CPU
remotely enqueues a ttwu to our runqueue:

CPU 0:                            CPU 1:

tick_sched_timer() {              ttwu_queue_remote()
       if (idle_cpu(CPU 0))
           ts->idle_jiffies++;
}

Here, idle_cpu() notes that &rq->wake_list is not empty and
hence won't consider the CPU as idle. As a result,
ts->idle_jiffies won't be incremented. But this is wrong because
we actually account the current jiffy to idle cputime. And that
jiffy won't get substracted from the nohz time delta. So in the
end, this jiffy is accounted twice.

Fix this by changing idle_cpu(smp_processor_id()) with
is_idle_task(current). This way the jiffy is substracted
correctly even if a ttwu operation is enqueued on the CPU.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org> # 3.5+
Link: http://lkml.kernel.org/r/1349308004-3482-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-10-05 10:22:20 +02:00
Linus Torvalds 16642a2e7b Power management updates for 3.7-rc1
* Improved system suspend/resume and runtime PM handling for the SH TMU, CMT
   and MTU2 clock event devices (also used by ARM/shmobile).
 
 * Generic PM domains framework extensions related to cpuidle support and
   domain objects lookup using names.
 
 * ARM/shmobile power management updates including improved support for the
   SH7372's A4S power domain containing the CPU core.
 
 * cpufreq changes related to AMD CPUs support from Matthew Garrett, Andre
   Przywara and Borislav Petkov.
 
 * cpu0 cpufreq driver from Shawn Guo.
 
 * cpufreq governor fixes related to the relaxing of limit from Michal Pecio.
 
 * OMAP cpufreq updates from Axel Lin and Richard Zhao.
 
 * cpuidle ladder governor fixes related to the disabling of states from
   Carsten Emde and me.
 
 * Runtime PM core updates related to the interactions with the system suspend
   core from Alan Stern and Kevin Hilman.
 
 * Wakeup sources modification allowing more helper functions to be called from
   interrupt context from John Stultz and additional diagnostic code from Todd
   Poynor.
 
 * System suspend error code path fix from Feng Hong.
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Merge tag 'pm-for-3.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael J Wysocki:

 - Improved system suspend/resume and runtime PM handling for the SH
   TMU, CMT and MTU2 clock event devices (also used by ARM/shmobile).

 - Generic PM domains framework extensions related to cpuidle support
   and domain objects lookup using names.

 - ARM/shmobile power management updates including improved support for
   the SH7372's A4S power domain containing the CPU core.

 - cpufreq changes related to AMD CPUs support from Matthew Garrett,
   Andre Przywara and Borislav Petkov.

 - cpu0 cpufreq driver from Shawn Guo.

 - cpufreq governor fixes related to the relaxing of limit from Michal
   Pecio.

 - OMAP cpufreq updates from Axel Lin and Richard Zhao.

 - cpuidle ladder governor fixes related to the disabling of states from
   Carsten Emde and me.

 - Runtime PM core updates related to the interactions with the system
   suspend core from Alan Stern and Kevin Hilman.

 - Wakeup sources modification allowing more helper functions to be
   called from interrupt context from John Stultz and additional
   diagnostic code from Todd Poynor.

 - System suspend error code path fix from Feng Hong.

Fixed up conflicts in cpufreq/powernow-k8 that stemmed from the
workqueue fixes conflicting fairly badly with the removal of support for
hardware P-state chips.  The changes were independent but somewhat
intertwined.

* tag 'pm-for-3.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (76 commits)
  Revert "PM QoS: Use spinlock in the per-device PM QoS constraints code"
  PM / Runtime: let rpm_resume() succeed if RPM_ACTIVE, even when disabled, v2
  cpuidle: rename function name "__cpuidle_register_driver", v2
  cpufreq: OMAP: Check IS_ERR() instead of NULL for omap_device_get_by_hwmod_name
  cpuidle: remove some empty lines
  PM: Prevent runtime suspend during system resume
  PM QoS: Use spinlock in the per-device PM QoS constraints code
  PM / Sleep: use resume event when call dpm_resume_early
  cpuidle / ACPI : move cpuidle_device field out of the acpi_processor_power structure
  ACPI / processor: remove pointless variable initialization
  ACPI / processor: remove unused function parameter
  cpufreq: OMAP: remove loops_per_jiffy recalculate for smp
  sections: fix section conflicts in drivers/cpufreq
  cpufreq: conservative: update frequency when limits are relaxed
  cpufreq / ondemand: update frequency when limits are relaxed
  properly __init-annotate pm_sysrq_init()
  cpufreq: Add a generic cpufreq-cpu0 driver
  PM / OPP: Initialize OPP table from device tree
  ARM: add cpufreq transiton notifier to adjust loops_per_jiffy for smp
  cpufreq: Remove support for hardware P-state chips from powernow-k8
  ...
2012-10-02 18:32:35 -07:00
Linus Torvalds 0b981cb94b Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar:
 "Continued quest to clean up and enhance the cputime code by Frederic
  Weisbecker, in preparation for future tickless kernel features.

  Other than that, smallish changes."

Fix up trivial conflicts due to additions next to each other in arch/{x86/}Kconfig

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  cputime: Make finegrained irqtime accounting generally available
  cputime: Gather time/stats accounting config options into a single menu
  ia64: Reuse system and user vtime accounting functions on task switch
  ia64: Consolidate user vtime accounting
  vtime: Consolidate system/idle context detection
  cputime: Use a proper subsystem naming for vtime related APIs
  sched: cpu_power: enable ARCH_POWER
  sched/nohz: Clean up select_nohz_load_balancer()
  sched: Fix load avg vs. cpu-hotplug
  sched: Remove __ARCH_WANT_INTERRUPTS_ON_CTXSW
  sched: Fix nohz_idle_balance()
  sched: Remove useless code in yield_to()
  sched: Add time unit suffix to sched sysctl knobs
  sched/debug: Limit sd->*_idx range on sysctl
  sched: Remove AFFINE_WAKEUPS feature flag
  s390: Remove leftover account_tick_vtime() header
  cputime: Consolidate vtime handling on context switch
  sched: Move cputime code to its own file
  cputime: Generalize CONFIG_VIRT_CPU_ACCOUNTING
  tile: Remove SD_PREFER_LOCAL leftover
  ...
2012-10-01 10:43:39 -07:00
Paul E. McKenney 593d1006cd Merge remote-tracking branch 'tip/core/rcu' into next.2012.09.25b
Resolved conflict in kernel/sched/core.c using Peter Zijlstra's
approach from https://lkml.org/lkml/2012/9/5/585.
2012-09-25 10:03:56 -07:00
John Stultz 92bb1fcf57 time: Only do nanosecond rounding on GENERIC_TIME_VSYSCALL_OLD systems
We only do rounding to the next nanosecond so we don't see minor
1ns inconsistencies in the vsyscall implementations. Since we're
changing the vsyscall implementations to avoid this, conditionalize
the rounding only to the GENERIC_TIME_VSYSCALL_OLD architectures.

Cc: Tony Luck <tony.luck@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-09-24 12:38:08 -04:00
John Stultz 576094b7f0 time: Introduce new GENERIC_TIME_VSYSCALL
Now that we moved everyone over to GENERIC_TIME_VSYSCALL_OLD,
introduce the new declaration and config option for the new
update_vsyscall method.

Cc: Tony Luck <tony.luck@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-09-24 12:38:08 -04:00
John Stultz 7063942116 time: Convert CONFIG_GENERIC_TIME_VSYSCALL to CONFIG_GENERIC_TIME_VSYSCALL_OLD
To help migrate archtectures over to the new update_vsyscall method,
redfine CONFIG_GENERIC_TIME_VSYSCALL as CONFIG_GENERIC_TIME_VSYSCALL_OLD

Cc: Tony Luck <tony.luck@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-09-24 12:38:07 -04:00
John Stultz d7b4202e05 time: Move timekeeper structure to timekeeper_internal.h for vsyscall changes
We're going to need to access the timekeeper in update_vsyscall,
so make the structure available for those who need it.

Cc: Tony Luck <tony.luck@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-09-24 12:38:05 -04:00
John Stultz b3c869d35b jiffies: Remove compile time assumptions about CLOCK_TICK_RATE
CLOCK_TICK_RATE is used to accurately caclulate exactly how
a tick will be at a given HZ.

This is useful, because while we'd expect NSEC_PER_SEC/HZ,
the underlying hardware will have some granularity limit,
so we won't be able to have exactly HZ ticks per second.

This slight error can cause timekeeping quality problems
when using the jiffies or other jiffies driven clocksources.
Thus we currently use compile time CLOCK_TICK_RATE value to
generate SHIFTED_HZ and NSEC_PER_JIFFIES, which we then use
to adjust the jiffies clocksource to correct this error.

Unfortunately though, since CLOCK_TICK_RATE is a compile
time value, and the jiffies clocksource is registered very
early during boot, there are a number of cases where there
are different possible hardware timers that have different
tick rates. This causes problems in cases like ARM where
there are numerous different types of hardware, each having
their own compile-time CLOCK_TICK_RATE, making it hard to
accurately support different hardware with a single kernel.

For the most part, this doesn't matter all that much, as not
too many systems actually utilize the jiffies or jiffies driven
clocksource. Usually there are other highres clocksources
who's granularity error is negligable.

Even so, we have some complicated calcualtions that we do
everywhere to handle these edge cases.

This patch removes the compile time SHIFTED_HZ value, and
introduces a register_refined_jiffies() function. This results
in the default jiffies clock as being assumed a perfect HZ
freq, and allows archtectures that care about jiffies accuracy
to call register_refined_jiffies() with the tick rate, specified
dynamically at boot.

This allows us, where necessary, to not have a compile time
CLOCK_TICK_RATE constant, simplifies the jiffies code, and
still provides a way to have an accurate jiffies clock.

NOTE: Since this patch does not add register_refinied_jiffies()
calls for every arch, it may cause time quality regressions
in some cases. Its likely these will not be noticable, but
if they are an issue, adding the following to the end of
setup_arch() should resolve the regression:
	register_refinied_jiffies(CLOCK_TICK_RATE)

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-09-24 12:38:05 -04:00
John Stultz a65bcc12ad alarmtimer: Rename alarmtimer_remove to alarmtimer_dequeue
Now that alarmtimer_remove has been simplified, change
its name to _dequeue to better match its paired _enqueue
function.

Cc: Arve Hjønnevåg <arve@android.com>
Cc: Colin Cross <ccross@android.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-09-24 12:38:03 -04:00
John Stultz dae373be9f alarmtimer: Use hrtimer per-alarm instead of per-base
Arve Hjønnevåg reported numerous crashes from the
"BUG_ON(timer->state != HRTIMER_STATE_CALLBACK)" check
in __run_hrtimer after it called alarmtimer_fired.

It ends up the alarmtimer code was not properly handling
possible failures of hrtimer_try_to_cancel, and because
these faulres occur when the underlying base hrtimer is
being run, this limits the ability to properly handle
modifications to any alarmtimers on that base.

Because much of the logic duplicates the hrtimer logic,
it seems that we might as well have a per-alarmtimer
hrtimer, and avoid the extra complextity of trying to
multiplex many alarmtimers off of one hrtimer.

Thus this patch moves the hrtimer to the alarm structure
and simplifies the management logic.

Changelog:
v2:
* Includes a fix for double alarm_start calls found by
  Arve

Cc: Arve Hjønnevåg <arve@android.com>
Cc: Colin Cross <ccross@android.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Arve Hjønnevåg <arve@android.com>
Tested-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-09-24 12:38:02 -04:00
Todd Poynor 59a93c27c4 alarmtimer: Implement minimum alarm interval for allowing suspend
alarmtimer suspend return -EBUSY if the next alarm will fire in less
than 2 seconds.  This allows one RTC seconds tick to occur subsequent
to this check before the alarm wakeup time is set, ensuring the wakeup
time is still in the future (assuming the RTC does not tick one more
second prior to setting the alarm).

If suspend is rejected due to an imminent alarm, hold a wakeup source
for 2 seconds to process the alarm prior to reattempting suspend.

If setting the alarm incurs an -ETIME for an alarm set in the past,
or any other problem setting the alarm, abort suspend and hold a
wakelock for 1 second while the alarm is allowed to be serviced or
other hopefully transient conditions preventing the alarm clear up.

Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-09-24 12:38:01 -04:00
Paul E. McKenney 803b0ebae9 time: RCU permitted to stop idle entry via softirq
The can_stop_idle_tick() function complains if a softirq vector is
raised too late in the idle-entry process, presumably in order to
prevent dangling softirq invocations from being delayed across the
full idle period, which might be indefinitely long -- and if softirq
was asserted any later than the call to this function, such a delay
might well happen.

However, RCU needs to be able to use softirq to stop idle entry in
order to be able to drain RCU callbacks from the current CPU, which in
turn enables faster entry into dyntick-idle mode, which in turn reduces
power consumption.  Because RCU takes this action at a well-defined
point in the idle-entry path, it is safe for RCU to take this approach.

This commit therefore silences the error message that is sometimes
produced when the going-idle CPU suddenly finds that it has an RCU_SOFTIRQ
to process.  The error message will continue to be issued for other
softirq vectors.

Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2012-09-23 07:42:52 -07:00
Linus Torvalds 519b3b742d Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Ingo Molnar:
 "One more timekeeping fix for v3.6"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Fix timeekeping_get_ns overflow on 32bit systems
2012-09-21 14:25:46 -07:00
Rafael J. Wysocki 00e8b26133 Merge branch 'pm-timers'
* pm-timers:
  PM: Do not use the syscore flag for runtime PM
  sh: MTU2: Basic runtime PM support
  sh: CMT: Basic runtime PM support
  sh: TMU: Basic runtime PM support
  PM / Domains: Do not measure start time for "irq safe" devices
  PM / Domains: Move syscore flag from subsys data to struct device
  PM / Domains: Rename the always_on device flag to syscore
  PM / Runtime: Allow helpers to be called by early platform drivers
  PM: Reorganize device PM initialization
  sh: MTU2: Introduce clock events suspend/resume routines
  sh: CMT: Introduce clocksource/clock events suspend/resume routines
  sh: TMU: Introduce clocksource/clock events suspend/resume routines
  timekeeping: Add suspend and resume of clock event devices
  PM / Domains: Add power off/on function for system core suspend stage
  PM / Domains: Introduce simplified power on routine for system resume
2012-09-17 20:25:18 +02:00
John Stultz ec145babe7 time: Fix timeekeping_get_ns overflow on 32bit systems
Daniel Lezcano reported seeing multi-second stalls from
keyboard input on his T61 laptop when NOHZ and CPU_IDLE
were enabled on a 32bit kernel.

He bisected the problem down to commit
1e75fa8be9 ("time: Condense timekeeper.xtime into xtime_sec").

After reproducing this issue, I narrowed the problem down
to the fact that timekeeping_get_ns() returns a 64bit
nsec value that hasn't been accumulated. In some cases
this value was being then stored in timespec.tv_nsec
(which is a long).

On 32bit systems, with idle times larger then 4 seconds
(or less, depending on the value of xtime_nsec), the
returned nsec value would overflow 32bits. This limited
kept time from increasing, causing timers to not expire.

The fix is to make sure we don't directly store the
result of timekeeping_get_ns() into a tv_nsec field,
instead using a 64bit nsec value which can then be
added into the timespec via timespec_add_ns().

Reported-and-bisected-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Link: http://lkml.kernel.org/r/1347405963-35715-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-09-13 17:39:14 +02:00
Alex Shi c1cc017c59 sched/nohz: Clean up select_nohz_load_balancer()
There is no load_balancer to be selected now. It just sets the
state of the nohz tick to stop.

So rename the function, pass the 'cpu' as a parameter and then
remove the useless call from tick_nohz_restart_sched_tick().

[ s/set_nohz_tick_stopped/nohz_balance_enter_idle/g
  s/clear_nohz_tick_stopped/nohz_balance_exit_idle/g ]
Signed-off-by: Alex Shi <alex.shi@intel.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1347261059-24747-1-git-send-email-alex.shi@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-09-13 16:52:05 +02:00
Charles Wang 749c8814f0 sched: Add missing call to calc_load_exit_idle()
Azat Khuzhin reported high loadavg in Linux v3.6

After checking the upstream scheduler code, I found Peter's commit:

  5167e8d541 sched/nohz: Rewrite and fix load-avg computation -- again

not fully applied, missing the call to calc_load_exit_idle().

After that idle exit in sampling window will always be calculated
to non-idle, and the load will be higher than normal.

This patch adds the missing call to calc_load_exit_idle().

Signed-off-by: Charles Wang <muming.wq@taobao.com>
Cc: stable@kernel.org
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1345449754-27130-1-git-send-email-muming.wq@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-09-04 14:30:29 +02:00
Rafael J. Wysocki adc78e6b99 timekeeping: Add suspend and resume of clock event devices
Some clock event devices, for example such that belong to PM domains,
need to be handled in a spcial way during the timekeeping suspend
and resume (which takes place in the system core, or "syscore",
stages of system power transitions) in analogy with clock sources.

Introduce .suspend() and .resume() callbacks for clock event devices
that will be executed by timekeeping_suspend/_resume(), respectively,
next the the clock sources' .suspend() and .resume() callbacks.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-09-04 01:36:01 +02:00
John Stultz cee58483cf time: Move ktime_t overflow checking into timespec_valid_strict
Andreas Bombe reported that the added ktime_t overflow checking added to
timespec_valid in commit 4e8b14526c ("time: Improve sanity checking of
timekeeping inputs") was causing problems with X.org because it caused
timeouts larger then KTIME_T to be invalid.

Previously, these large timeouts would be clamped to KTIME_MAX and would
never expire, which is valid.

This patch splits the ktime_t overflow checking into a new
timespec_valid_strict function, and converts the timekeeping codes
internal checking to use this more strict function.

Reported-and-tested-by: Andreas Bombe <aeb@debian.org>
Cc: Zhouping Liu <zliu@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-01 10:24:48 -07:00
John Stultz bf2ac31219 time: Avoid making adjustments if we haven't accumulated anything
If update_wall_time() is called and the current offset isn't large
enough to accumulate, avoid re-calling timekeeping_adjust which may
change the clock freq and can cause 1ns inconsistencies with
CLOCK_REALTIME_COARSE/CLOCK_MONOTONIC_COARSE.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1345595449-34965-5-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-08-22 10:42:13 +02:00
John Stultz 6ea565a9be time: Avoid potential shift overflow with large shift values
Andreas Schwab noticed that the 1 << tk->shift could overflow if the
shift value was greater than 30, since 1 would be a 32bit long on
32bit architectures. This issue was introduced by 1e75fa8be (time:
Condense timekeeper.xtime into xtime_sec)

Use 1ULL instead to ensure we don't overflow on the shift.

Reported-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/1345595449-34965-4-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-08-22 10:42:13 +02:00
Andreas Schwab 85dc8f05c9 time: Fix casting issue in timekeeping_forward_now
arch_gettimeoffset returns a u32 value which when shifted by tk->shift
can overflow. This issue was introduced with 1e75fa8be (time: Condense
timekeeper.xtime into xtime_sec)

Cast it to u64 first.

Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/1345595449-34965-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-08-22 10:42:13 +02:00
John Stultz 784ffcbb96 time: Ensure we normalize the timekeeper in tk_xtime_add
Andreas noticed problems with resume on specific hardware after commit
1e75fa8b (time: Condense timekeeper.xtime into xtime_sec) combined
with commit b44d50dca (time: Fix casting issue in tk_set_xtime and
tk_xtime_add)

After some digging I realized we aren't normalizing the timekeeper
after the add. Add the missing normalize call.

Reported-by: Andreas Schwab <schwab@linux-m68k.org>
Tested-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/1345595449-34965-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-08-22 10:42:12 +02:00
John Stultz 4e8b14526c time: Improve sanity checking of timekeeping inputs
Unexpected behavior could occur if the time is set to a value large
enough to overflow a 64bit ktime_t (which is something larger then the
year 2262).

Also unexpected behavior could occur if large negative offsets are
injected via adjtimex.

So this patch improves the sanity check timekeeping inputs by
improving the timespec_valid() check, and then makes better use of
timespec_valid() to make sure we don't set the time to an invalid
negative value or one that overflows ktime_t.

Note: This does not protect from setting the time close to overflowing
ktime_t and then letting natural accumulation cause the overflow.

Reported-by: CAI Qian <caiqian@redhat.com>
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Zhouping Liu <zliu@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1344454580-17031-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-08-15 15:54:01 +02:00
Ingo Molnar 1d17d17484 time: Fix adjustment cleanup bug in timekeeping_adjust()
Tetsuo Handa reported that sporadically the system clock starts
counting up too quickly which is enough to confuse the hangcheck
timer to print a bogus stall warning.

Commit 2a8c0883 "time: Move xtime_nsec adjustment underflow handling
timekeeping_adjust" overlooked this exit path:

        } else
                return;

which should really be a proper exit sequence, fixing the bug as a
side effect.

Also make the flow more readable by properly balancing curly
braces.

Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> wrote:
Tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> wrote:
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: john.stultz@linaro.org
Cc: a.p.zijlstra@chello.nl
Cc: richardcochran@gmail.com
Cc: prarit@redhat.com
Link: http://lkml.kernel.org/r/20120804192114.GA28347@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-08-05 12:37:14 +02:00
John Stultz 4e250fdde9 time: Remove all direct references to timekeeper
Ingo noted that the numerous timekeeper.value references made
the timekeeping code ugly and caused many long lines that
had to be broken up. He recommended replacing timekeeper.value
references with tk->value.

This patch provides a local tk value for all top level time
functions and sets it to &timekeeper. Then all timekeeper
access is done via a tk pointer.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1343414893-45779-6-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-31 17:09:14 +02:00
John Stultz 6d0ef903e2 time: Clean up offs_real/wall_to_mono and offs_boot/total_sleep_time updates
For performance reasons, we maintain ktime_t based duplicates of
wall_to_monotonic (offs_real) and total_sleep_time (offs_boot).

Since large problems could occur (such as the resume regression
on 3.5-rc7, or the leapsecond hrtimer issue) if these value
pairs were to be inconsistently updated, this patch this cleans
up how we modify these value pairs to ensure we are always
consistent.

As a side-effect this is also more efficient as we only
caulculate the duplicate values when they are changed,
rather then every update_wall_time call.

This also provides WARN_ONs to detect if future changes break
the invariants.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1343414893-45779-5-git-send-email-john.stultz@linaro.org
[ Cleaned up minor style issues. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-31 17:09:14 +02:00
John Stultz d4e3ab384b time: Clean up stray newlines
Ingo noted inconsistent newline usage between functions.
This patch cleans those up.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1343414893-45779-4-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-31 17:09:13 +02:00
John Stultz 02ab20ae38 time/jiffies: Rename ACTHZ to SHIFTED_HZ
Ingo noted that ACTHZ is a confusing name, and requested it
be renamed, so this patch renames ACTHZ to SHIFTED_HZ to
better describe it.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1343414893-45779-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-31 17:09:12 +02:00
Ingo Molnar 1f815faec4 Merge branch 'linus' into timers/urgent
Merge in Linus's branch which already has timers/core merged.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-31 17:05:27 +02:00
John Stultz b44d50dcac time: Fix casting issue in tk_set_xtime and tk_xtime_add
commit 1e75fa8b (time: Condense timekeeper.xtime into xtime_sec)
introduced helper functions which apply a timespec to the core
internal timekeeper data. The internal storage type is u64. The
timespec tv_nsec value must be shifted before set or added to the
internal value. tv_nsec is a long, which is 32bit on a 32bit system,
so without casting tv_nsec to u64 we lose the bits which are shifted
over the 32bit boundary.

Add the proper typecasts.

Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1343074957-16541-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-24 16:48:45 +02:00
Linus Torvalds 3992c03212 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer core changes from Ingo Molnar:
 "Continued cleanups of the core time and NTP code, plus more nohz work
  preparing for tick-less userspace execution."

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Rework timekeeping functions to take timekeeper ptr as argument
  time: Move xtime_nsec adjustment underflow handling timekeeping_adjust
  time: Move arch_gettimeoffset() usage into timekeeping_get_ns()
  time: Refactor accumulation of nsecs to secs
  time: Condense timekeeper.xtime into xtime_sec
  time: Explicitly use u32 instead of int for shift values
  time: Whitespace cleanups per Ingo%27s requests
  nohz: Move next idle expiry time record into idle logic area
  nohz: Move ts->idle_calls incrementation into strict idle logic
  nohz: Rename ts->idle_tick to ts->last_tick
  nohz: Make nohz API agnostic against idle ticks cputime accounting
  nohz: Separate idle sleeping time accounting from nohz logic
  timers: Improve get_next_timer_interrupt()
  timers: Add accounting of non deferrable timers
  timers: Consolidate base->next_timer update
  timers: Create detach_if_pending() and use it
2012-07-22 11:35:46 -07:00
Linus Torvalds 16d286e656 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU changes from Ingo Molnar:
 "Quoting from Paul, the major features of this series are:

  1. Preventing latency spikes of more than 200 microseconds for
     kernels built with NR_CPUS=4096, which is reportedly becoming the
     default for some distros.  This is a first step, as it does not
     help with systems that actually -have- 4096 CPUs (work on this case
     is in progress, but is not yet ready for mainline).

     This category also includes improving concurrency of rcu_barrier(),
     placed here due to conflicts.  Posted to LKML at:

      https://lkml.org/lkml/2012/6/22/381

     Note that patches 18-22 of that series have been defered to 3.7, as
     they have not yet proven themselves to be mainline-ready (and yes,
     these are the ones intended to get rid of RCU's latency spikes for
     systems that actually have 4096 CPUs).

  2. Updates to documentation and rcutorture fixes, the latter category
     including improvements to rcu_barrier() testing.  Posted to LKML at

      http://lkml.indiana.edu/hypermail/linux/kernel/1206.1/04094.html.

  3. Miscellaneous fixes posted to LKML at:

      https://lkml.org/lkml/2012/6/22/500

     with the exception of the last commit, which was posted here:

      http://www.gossamer-threads.com/lists/linux/kernel/1561830

  4. RCU_FAST_NO_HZ fixes and improvements.  Posted to LKML at:

      http://lkml.indiana.edu/hypermail/linux/kernel/1206.1/00006.html
      http://www.gossamer-threads.com/lists/linux/kernel/1561833

     The first four patches of the first series went into 3.5 to fix a
     regression.

  5. Code-style fixes.  These were posted to LKML at

      http://lkml.indiana.edu/hypermail/linux/kernel/1205.2/01180.html
      http://lkml.indiana.edu/hypermail/linux/kernel/1205.2/01181.html"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits)
  rcu: Fix broken strings in RCU's source code.
  rcu: Fix code-style issues involving "else"
  rcu: Introduce check for callback list/count mismatch
  rcu: Make RCU_FAST_NO_HZ respect nohz= boot parameter
  rcu: Fix qlen_lazy breakage
  rcu: Round FAST_NO_HZ lazy timeout to nearest second
  rcu: The rcu_needs_cpu() function is not a quiescent state
  rcu: Dump only the current CPU's buffers for idle-entry/exit warnings
  rcu: Add check for CPUs going offline with callbacks queued
  rcu: Disable preemption in rcu_blocking_is_gp()
  rcu: Prevent uninitialized string in RCU CPU stall info
  rcu: Fix rcu_is_cpu_idle() #ifdef in TINY_RCU
  rcu: Split RCU core processing out of __call_rcu()
  rcu: Prevent __call_rcu() from invoking RCU core on offline CPUs
  rcu: Make __call_rcu() handle invocation from idle
  rcu: Remove function versions of __kfree_rcu and __is_kfree_rcu_offset
  rcu: Consolidate tree/tiny __rcu_read_{,un}lock() implementations
  rcu: Remove return value from rcu_assign_pointer()
  key: Remove extraneous parentheses from rcu_assign_keypointer()
  rcu: Remove return value from RCU_INIT_POINTER()
  ...
2012-07-22 10:45:05 -07:00
Linus Torvalds 6f70242858 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
One more time/ntp fix pulled from Ingo Molnar.

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ntp: Fix STA_INS/DEL clearing bug
2012-07-18 10:36:02 -07:00
Ingo Molnar eec19d1a0d Merge branch 'linus' into timers/core
Resolve semantic conflict in kernel/time/timekeeping.c.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-18 11:25:55 +02:00
Thomas Gleixner 3e997130bd timekeeping: Add missing update call in timekeeping_resume()
The leap second rework unearthed another issue of inconsistent data.

On timekeeping_resume() the timekeeper data is updated, but nothing
calls timekeeping_update(), so now the update code in the timer
interrupt sees stale values.

This has been the case before those changes, but then the timer
interrupt was using stale data as well so this went unnoticed for quite
some time.

Add the missing update call, so all the data is consistent everywhere.

Reported-by: Andreas Schwab <schwab@linux-m68k.org>
Reported-and-tested-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Reported-and-tested-by: Martin Steigerwald <Martin@lichtvoll.de>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Linux PM list <linux-pm@vger.kernel.org>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-16 10:02:17 -07:00
John Stultz f726a697d0 time: Rework timekeeping functions to take timekeeper ptr as argument
As part of cleaning up the timekeeping code, this patch converts
a number of internal functions to takei a timekeeper ptr as an
argument, so that the internal functions don't access the global
timekeeper structure directly. This allows for further optimizations
to reduce lock hold time later.

This patch has been updated to include more consistent usage of the
timekeeper value, by making sure it is always passed as a argument
to non top-level functions.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1342156917-25092-9-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-15 10:39:07 +02:00
John Stultz 2a8c0883c3 time: Move xtime_nsec adjustment underflow handling timekeeping_adjust
When we make adjustments speeding up the clock, its possible
for xtime_nsec to underflow. We already handle this properly,
but we do so from update_wall_time() instead of the more logical
timekeeping_adjust(), where the possible underflow actually
occurs.

Thus, move the correction logic to the timekeeping_adjust, which
is the function that causes the issue. Making update_wall_time()
more readable.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1342156917-25092-8-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-15 10:39:07 +02:00
John Stultz f2a5a0854e time: Move arch_gettimeoffset() usage into timekeeping_get_ns()
Since we call arch_gettimeoffset() in all the accessor
functions, move arch_gettimeoffset() calls into
timekeeping_get_ns() and timekeeping_get_ns_raw() to simplify
the code.

This also makes the code easier to maintain as we don't have to
worry about forgetting the arch_gettimeoffset() as has happened
in the past.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1342156917-25092-7-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-15 10:39:06 +02:00
John Stultz 1f4f948706 time: Refactor accumulation of nsecs to secs
We do the exact same logic moving nsecs to secs in the
timekeeper in multiple places, so condense this into a
single function.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1342156917-25092-6-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-15 10:39:06 +02:00
John Stultz 1e75fa8be9 time: Condense timekeeper.xtime into xtime_sec
The timekeeper struct has a xtime_nsec, which keeps the
sub-nanosecond remainder.  This ends up being somewhat
duplicative of the timekeeper.xtime.tv_nsec value, and we
have to do extra work to keep them apart, copying the full
nsec portion out and back in over and over.

This patch simplifies some of the logic by taking the timekeeper
xtime value and splitting it into timekeeper.xtime_sec and
reuses the timekeeper.xtime_nsec for the sub-second portion
(stored in higher res shifted nanoseconds).

This simplifies some of the accumulation logic. And will
allow for more accurate timekeeping once the vsyscall code
is updated to use the shifted nanosecond remainder.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1342156917-25092-5-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-15 10:39:06 +02:00
John Stultz fee84c43e6 time: Explicitly use u32 instead of int for shift values
Ingo noted that using a u32 instead of int for shift values
would be better to make sure the compiler doesn't unnecessarily
use complex signed arithmetic.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1342156917-25092-4-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-15 10:39:05 +02:00
John Stultz 42e71e81f5 time: Whitespace cleanups per Ingo%27s requests
Ingo noted a number of places where there is inconsistent
use of whitespace. This patch tries to address the main
culprits.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1342156917-25092-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-15 10:39:05 +02:00
Thomas Gleixner e8b9dd7e24 Merge branch 'timers/urgent' into timers/core
Reason: Update to upstream changes to avoid further conflicts.
Fixup a trivial merge conflict in kernel/time/tick-sched.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-15 10:24:53 +02:00
John Stultz 6b1859dba0 ntp: Fix STA_INS/DEL clearing bug
In commit 6b43ae8a61, I
introduced a bug that kept the STA_INS or STA_DEL bit
from being cleared from time_status via adjtimex()
without forcing STA_PLL first.

Usually once the STA_INS is set, it isn't cleared
until the leap second is applied, so its unlikely this
affected anyone. However during testing I noticed it
took some effort to cancel a leap second once STA_INS
was set.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
CC: stable@vger.kernel.org # 3.4
Link: http://lkml.kernel.org/r/1342156917-25092-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-15 09:48:49 +02:00