linux-toradex.git/kernel/hrtimer.c, branch v3.2.14-rt24

hrtimer-fix-reprogram-madness.patch

2012-04-10T21:37:01+00:00

Signed-off-by: Thomas Gleixner

hrtimer: Add missing debug_activate() aid [Was: Re: [ANNOUNCE] 3.0.6-rt17]

2012-04-10T21:37:01+00:00

On Fri, Oct 07, 2011 at 10:25:25AM -0700, Fernando Lopez-Lezcano wrote:
> On 10/06/2011 06:15 PM, Thomas Gleixner wrote:
> >Dear RT Folks,
> >
> >I'm pleased to announce the 3.0.6-rt17 release.
> 
> Hi and thanks again. So far this one is not hanging which is very
> good news. But I still see the hrtimer_fixup_activate warnings I
> reported for rt16...

Hi Fernando,

I think below patch will smooth your concern?

Thanks,
Yong

hrtimer: Don't call the timer handler from hrtimer_start

2012-04-10T21:37:01+00:00

 [] __delay+0xf/0x11
 [] do_raw_spin_lock+0xd2/0x13c
 [] _raw_spin_lock+0x60/0x73              rt_b->rt_runtime_lock
 [] ? sched_rt_period_timer+0xad/0x281
 [] sched_rt_period_timer+0xad/0x281
 [] __run_hrtimer+0x1e4/0x347
 [] ? enqueue_rt_entity+0x36/0x36
 [] __hrtimer_start_range_ns+0x2b5/0x40a  base->cpu_base->lock  (lock_hrtimer_base)
 [] __enqueue_rt_entity+0x26f/0x2aa       rt_b->rt_runtime_lock (start_rt_bandwidth)
 [] enqueue_rt_entity+0x28/0x36
 [] enqueue_task_rt+0x3d/0xb0
 [] enqueue_task+0x5d/0x64
 [] task_setprio+0x210/0x29c              rq->lock
 [] __rt_mutex_adjust_prio+0x25/0x2a      p->pi_lock
 [] task_blocks_on_rt_mutex+0x196/0x20f

Instead make __hrtimer_start_range_ns() return -ETIME when the timer
is in the past. Since body actually uses the hrtimer_start*() return
value its pretty safe to wreck it.

Also, it will only ever return -ETIME for timer->irqsafe || !wakeup
timers.

Signed-off-by: Peter Zijlstra

hrtimer: fixup hrtimer callback changes for preempt-rt

2012-04-10T21:37:01+00:00

In preempt-rt we can not call the callbacks which take sleeping locks
from the timer interrupt context.

Bring back the softirq split for now, until we fixed the signal
delivery problem for real.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar

hrtimers: prepare full preemption

2012-04-10T21:37:00+00:00

Make cancellation of a running callback in softirq context safe
against preemption.

Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner

latency-hist.patch

2012-04-10T21:36:42+00:00

This patch provides a recording mechanism to store data of potential
sources of system latencies. The recordings separately determine the
latency caused by a delayed timer expiration, by a delayed wakeup of the
related user space program and by the sum of both. The histograms can be
enabled and reset individually. The data are accessible via the debug
filesystem. For details please consult Documentation/trace/histograms.txt.

Signed-off-by: Carsten Emde 
Signed-off-by: Thomas Gleixner

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

2011-11-28T16:43:52+00:00

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hrtimer: Fix extra wakeups from __remove_hrtimer()
  timekeeping: add arch_offset hook to ktime_get functions
  clocksource: Avoid selecting mult values that might overflow when adjusted
  time: Improve documentation of timekeeeping_adjust()

hrtimer: Fix extra wakeups from __remove_hrtimer()

2011-11-19T11:17:37+00:00

__remove_hrtimer() attempts to reprogram the clockevent device when
the timer being removed is the next to expire. However,
__remove_hrtimer() reprograms the clockevent *before* removing the
timer from the timerqueue and thus when hrtimer_force_reprogram()
finds the next timer to expire it finds the timer we're trying to
remove.

This is especially noticeable when the system switches to NOHz mode
and the system tick is removed. The timer tick is removed from the
system but the clockevent is programmed to wakeup in another HZ
anyway.

Silence the extra wakeup by removing the timer from the timerqueue
before calling hrtimer_force_reprogram() so that we actually program
the clockevent for the next timer to expire.

This was broken by 998adc3 "hrtimers: Convert hrtimers to use
timerlist infrastructure".

Signed-off-by: Jeff Ohlstein 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1321660030-8520-1-git-send-email-johlstei@codeaurora.org
Signed-off-by: Thomas Gleixner

kernel: Map most files to use export.h instead of module.h

2011-10-31T13:20:12+00:00

The changed files were only including linux/module.h for the
EXPORT_SYMBOL infrastructure, and nothing else.  Revector them
onto the isolated export header for faster compile times.

Nothing to see here but a whole lot of instances of:

  -#include 
  +#include 

This commit is only changing the kernel dir; next targets
will probably be mm, fs, the arch dirs, etc.

Signed-off-by: Paul Gortmaker

hrtimers: Fix typo causing erratic timers

2011-05-25T22:31:58+00:00

commit 9ec2690758a5 ("timerfd: Manage cancelable timers in timerfd")
introduced a CONFIG_HIGHRES_TIMERS (should be CONFIG_HIGH_RES_TIMERS)
typo, which caused applications depending on CLOCK_REALTIME timers to
become sluggy due to the fact that the time base of the realtime
timers was not updated when the wall clock time was set.

This causes anything from 100% CPU use for some applications to odd
delays and hickups.

Reported-bisected-and-tested-by: Anca Emanuel 
Tested-by: Linus Torvalds 
Fatfingered-by: Thomas Gleixner 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Linus Torvalds