linux-toradex.git/kernel/time/timer_list.c, branch v3.10.2

timer_list: Convert timer list to be a proper seq_file

2013-04-17T18:51:02+00:00

When running with 4096 cores attemping to read /proc/timer_list will fail
with an ENOMEM condition.  On a sufficantly large systems the total amount
of data is more then 4mb, so it won't fit into a single buffer.  The
failure can also occur on smaller systems when memory fragmentation is
high as reported by Dave Jones.

Convert /proc/timer_list to a proper seq_file with its own iterator.  This
is a little more complex given that we have to make two passes with two
separate headers.

sysrq_timer_list_show also needed to be updated to reflect the fact that
now timer_list_show only does one cpu at at time.

Signed-off-by: Nathan Zimmer 
Reported-by: Dave Jones 
Cc: John Stultz 
Cc: Stephen Boyd 
Link: http://lkml.kernel.org/r/1364345790-14577-3-git-send-email-nzimmer@sgi.com
Signed-off-by: Thomas Gleixner

timer_list: Split timer_list_show_tickdevices

2013-04-17T18:51:02+00:00

Split timer_list_show_tickdevices() into the header printout and pull
the rest up to timer_list_show. This is a preparatory patch for
converting timer_list to a proper seqfile with its own iterator

Signed-off-by: Nathan Zimmer 
Reported-by: Dave Jones 
Cc: John Stultz 
Cc: Stephen Boyd 
Link: http://lkml.kernel.org/r/1364345790-14577-2-git-send-email-nzimmer@sgi.com
Signed-off-by: Thomas Gleixner

nohz: Rename ts->idle_tick to ts->last_tick

2012-06-11T18:07:17+00:00

Now that idle and nohz logics are going to be independant each others,
ts->idle_tick becomes too much a biased name to describe the field that
saves the last scheduled tick on top of which we re-calculate the next
tick to schedule when the timer is restarted.

We want to reuse this even to stop the tick outside idle cases. So let's
rename it to some more generic name: ts->last_tick.

This changes a bit the timer list stat export so we need to increase its
version.

Signed-off-by: Frederic Weisbecker 
Cc: Alessio Igor Bogani 
Cc: Andrew Morton 
Cc: Avi Kivity 
Cc: Chris Metcalf 
Cc: Christoph Lameter 
Cc: Daniel Lezcano 
Cc: Geoff Levand 
Cc: Gilad Ben Yossef 
Cc: Hakan Akkan 
Cc: Ingo Molnar 
Cc: Kevin Hilman 
Cc: Max Krasnyansky 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Stephen Hemminger 
Cc: Steven Rostedt 
Cc: Sven-Thorsten Dietrich 
Cc: Thomas Gleixner

timer debug: Hide kernel addresses via %pK in /proc/timer_list

2011-02-12T13:11:56+00:00

In the continuing effort to avoid kernel addresses leaking to
unprivileged users, this patch switches to %pK for
/proc/timer_list reporting.

Signed-off-by: Kees Cook 
Cc: John Stultz 
Cc: Dan Rosenberg 
Cc: Eugene Teo 
Cc: Linus Torvalds 
LKML-Reference: <20110212032125.GA23571@outflux.net>
Signed-off-by: Ingo Molnar

hrtimers: Convert hrtimers to use timerlist infrastructure

2010-12-10T19:54:35+00:00

Converts the hrtimer code to use the new timerlist infrastructure

Signed-off-by: John Stultz 
LKML Reference: <1290136329-18291-3-git-send-email-john.stultz@linaro.org>
Reviewed-by: Thomas Gleixner 
CC: Alessandro Zummo 
CC: Thomas Gleixner 
CC: Richard Cochran

sched: Intoduce get_cpu_iowait_time_us()

2010-05-09T17:35:27+00:00

For the ondemand cpufreq governor, it is desired that the iowait
time is microaccounted in a similar way as idle time is.

This patch introduces the infrastructure to account and expose
this information via the get_cpu_iowait_time_us() function.

[akpm@linux-foundation.org: fix CONFIG_NO_HZ=n build]
Signed-off-by: Arjan van de Ven 
Signed-off-by: Andrew Morton 
Reviewed-by: Rik van Riel 
Acked-by: Peter Zijlstra 
Cc: davej@redhat.com
LKML-Reference: <20100509082523.284feab6@infradead.org>
Signed-off-by: Ingo Molnar

clockevents: Sanitize min_delta_ns adjustment and prevent overflows

2010-03-12T18:10:29+00:00

The current logic which handles clock events programming failures can
increase min_delta_ns unlimited and even can cause overflows.

Sanitize it by:
 - prevent zero increase when min_delta_ns == 1
 - limiting min_delta_ns to a jiffie
 - bail out if the jiffie limit is hit
 - add retries stats for /proc/timer_list so we can gather data

Reported-by: Uwe Kleine-Koenig 
Signed-off-by: Thomas Gleixner

cpumask: avoid dereferencing struct cpumask

2009-12-17T01:13:29+00:00

struct cpumask will be undefined soon with CONFIG_CPUMASK_OFFSTACK=y,
to avoid them being declared on the stack.

cpumask_bits() does what we want here (of course, this code is crap).

Signed-off-by: Rusty Russell 
To: Thomas Gleixner

hrtimers: Convert to raw_spinlocks

2009-12-14T22:55:34+00:00

Convert locks which cannot be sleeping locks in preempt-rt to
raw_spinlocks.

Signed-off-by: Thomas Gleixner 
Acked-by: Peter Zijlstra 
Acked-by: Ingo Molnar

hrtimer: Tune hrtimer_interrupt hang logic

2009-12-10T12:08:11+00:00

The hrtimer_interrupt hang logic adjusts min_delta_ns based on the
execution time of the hrtimer callbacks.

This is error-prone for virtual machines, where a guest vcpu can be
scheduled out during the execution of the callbacks (and the callbacks
themselves can do operations that translate to blocking operations in
the hypervisor), which in can lead to large min_delta_ns rendering the
system unusable.

Replace the current heuristics with something more reliable. Allow the
interrupt code to try 3 times to catch up with the lost time. If that
fails use the total time spent in the interrupt handler to defer the
next timer interrupt so the system can catch up with other things
which got delayed. Limit that deferment to 100ms.

The retry events and the maximum time spent in the interrupt handler
are recorded and exposed via /proc/timer_list

Inspired by a patch from Marcelo.

Reported-by: Michael Tokarev 
Signed-off-by: Thomas Gleixner 
Tested-by: Marcelo Tosatti 
Cc: kvm@vger.kernel.org