linux-toradex.git/kernel/itimer.c, branch v3.15-rc4

itimer: Use printk_once instead of WARN_ONCE

2012-04-10T09:00:30+00:00

David pointed out, that WARN_ONCE() to report usage of an deprecated
misfeature make folks unhappy. Use printk_once() instead.

Andrew told me to stop grumbling and to remove the silly typecast
while touching the file.

Reported-by: David Rientjes 
Cc: Andrew Morton 
Signed-off-by: Thomas Gleixner

itimer: Schedule silent NULL pointer fixup in setitimer() for removal

2012-03-30T13:43:33+00:00

setitimer() should return -EFAULT if called with an invalid pointer
for value. The current code excludes a NULL pointer from this rule and
silently uses it to stop the timer. This violates the spec.

Warn about user space apps which rely on that feature and schedule it
for removal.

[ tglx: Massaged changelog, warn message and Doc entry ]

Signed-off-by: Sasikantha babu 
Link: http://lkml.kernel.org/r/1332340854-26053-1-git-send-email-sasikanth.v19@gmail.com
Signed-off-by: Thomas Gleixner

[S390] cputime: add sparse checking and cleanup

2011-12-15T13:56:19+00:00

Make cputime_t and cputime64_t nocast to enable sparse checking to
detect incorrect use of cputime. Drop the cputime macros for simple
scalar operations. The conversion macros are still needed.

Signed-off-by: Martin Schwidefsky

itimers: Fix racy writes to cpu_itimer fields

2009-11-18T15:32:12+00:00

incr_error and error fields of struct cpu_itimer are used when calculating
next timer tick in check_cpu_itimers() and should not be modified without
tsk->sighand->siglock taken.

Signed-off-by: Stanislaw Gruszka 
LKML-Reference: <1253802903-979-1-git-send-email-sgruszka@redhat.com> 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Signed-off-by: Andrew Morton 
Signed-off-by: Thomas Gleixner

itimers: Add tracepoints for itimer

2009-08-29T12:10:07+00:00

Add tracepoints for all itimer variants: ITIMER_REAL, ITIMER_VIRTUAL
and ITIMER_PROF.

[ tglx: Fixed comments and made the output more readable, parseable
  	and consistent. Replaced pid_vnr by pid_nr because the hrtimer
  	callback can happen in any namespace ]

Signed-off-by: Xiao Guangrong 
Cc: Steven Rostedt 
Cc: Frederic Weisbecker 
Cc: Mathieu Desnoyers 
Cc: Anton Blanchard 
Cc: Peter Zijlstra 
Cc: KOSAKI Motohiro 
Cc: Zhaolei 
LKML-Reference: <4A7F8B6E.2010109@cn.fujitsu.com>
Signed-off-by: Thomas Gleixner

cputime: Optimize jiffies_to_cputime(1)

2009-08-03T12:48:36+00:00

For powerpc with CONFIG_VIRT_CPU_ACCOUNTING
jiffies_to_cputime(1) is not compile time constant and run time
calculations are quite expensive. To optimize we use
precomputed value. For all other architectures is is
preprocessor definition.

Signed-off-by: Stanislaw Gruszka 
Acked-by: Peter Zijlstra 
Acked-by: Thomas Gleixner 
Cc: Oleg Nesterov 
Cc: Andrew Morton 
Cc: Paul Mackerras 
Cc: Benjamin Herrenschmidt 
LKML-Reference: <1248862529-6063-5-git-send-email-sgruszka@redhat.com>
Signed-off-by: Ingo Molnar

itimers: Fix periodic tics precision

2009-08-03T12:48:35+00:00

Measure ITIMER_PROF and ITIMER_VIRT timers interval error
between real ticks and requested by user. Take it into account
when scheduling next tick.

This patch introduce possibility where time between two
consecutive tics is smaller then requested interval, it
preserve however dependency that n tick is generated not
earlier than n*interval time - counting from the beginning of
periodic signal generation.

Signed-off-by: Stanislaw Gruszka 
Acked-by: Peter Zijlstra 
Acked-by: Thomas Gleixner 
Cc: Oleg Nesterov 
Cc: Andrew Morton 
Cc: Paul Mackerras 
Cc: Benjamin Herrenschmidt 
LKML-Reference: <1248862529-6063-3-git-send-email-sgruszka@redhat.com>
Signed-off-by: Ingo Molnar

itimers: Merge ITIMER_VIRT and ITIMER_PROF

2009-08-03T12:48:35+00:00

Both cpu itimers have same data flow in the few places, this
patch make unification of code related with VIRT and PROF
itimers.

Signed-off-by: Stanislaw Gruszka 
Acked-by: Peter Zijlstra 
Acked-by: Thomas Gleixner 
Cc: Oleg Nesterov 
Cc: Andrew Morton 
Cc: Paul Mackerras 
Cc: Benjamin Herrenschmidt 
LKML-Reference: <1248862529-6063-2-git-send-email-sgruszka@redhat.com>
Signed-off-by: Ingo Molnar

timers: split process wide cpu clocks/timers

2009-02-05T12:04:33+00:00

Change the process wide cpu timers/clocks so that we:

 1) don't mess up the kernel with too many threads,
 2) don't have a per-cpu allocation for each process,
 3) have no impact when not used.

In order to accomplish this we're going to split it into two parts:

 - clocks; which can take all the time they want since they run
           from user context -- ie. sys_clock_gettime(CLOCK_PROCESS_CPUTIME_ID)

 - timers; which need constant time sampling but since they're
           explicity used, the user can pay the overhead.

The clock readout will go back to a full sum of the thread group, while the
timers will run of a global 'clock' that only runs when needed, so only
programs that make use of the facility pay the price.

Signed-off-by: Peter Zijlstra 
Reviewed-by: Ingo Molnar 
Signed-off-by: Ingo Molnar

[CVE-2009-0029] System call wrappers part 05

2009-01-14T13:15:20+00:00

Signed-off-by: Heiko Carstens