linux-toradex.git/include/linux/timer.h, branch v2.6.23-rc5

Add a flag to indicate deferrable timers in /proc/timer_stats

2007-07-16T16:05:45+00:00

Add a flag in /proc/timer_stats to indicate deferrable timers.  This will
let developers/users to differentiate between types of tiemrs in
/proc/timer_stats.

Deferrable timer and normal timer will appear in /proc/timer_stats as below.
  10D,     1 swapper          queue_delayed_work_on (delayed_work_timer_fn)
   10,     1 swapper          queue_delayed_work_on (delayed_work_timer_fn)

Also version of timer_stats changes from v0.1 to v0.2

Signed-off-by: Venkatesh Pallipadi 
Acked-by: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: john stultz 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Remove unnecessary includes of spinlock.h under include/linux

2007-07-16T16:05:42+00:00

Remove the obviously unnecessary includes of  under the
include/linux/ directory, and fix the couple errors that are introduced as
a result of that.

Signed-off-by: Robert P. J. Day 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

NOHZ: prevent multiplication overflow - stop timer for huge timeouts

2007-05-30T01:11:10+00:00

get_next_timer_interrupt() returns a delta of (LONG_MAX > 1) in case
there is no timer pending. On 64 bit machines this results in a
multiplication overflow in tick_nohz_stop_sched_tick().

Reported by: Dave Miller 

Make the return value a constant and limit the return value to a 32 bit
value.

When the max timeout value is returned, we can safely stop the tick
timer device. The max jiffies delta results in a 12 days timeout for
HZ=1000.

In the long term the get_next_timer_interrupt() code needs to be
reworked to return ktime instead of jiffies, but we have to wait until
the last users of the original NO_IDLE_HZ code are converted.

Signed-off-by: Thomas Gleixner 
Acked-off-by: David S. Miller 
Signed-off-by: Linus Torvalds

Add support for deferrable timers

2007-05-08T18:15:05+00:00

Introduce a new flag for timers - deferrable: Timers that work normally
when system is busy.  But, will not cause CPU to come out of idle (just to
service this timer), when CPU is idle.  Instead, this timer will be
serviced when CPU eventually wakes up with a subsequent non-deferrable
timer.

The main advantage of this is to avoid unnecessary timer interrupts when
CPU is idle.  If the routine currently called by a timer can wait until
next event without any issues, this new timer can be used to setup timer
event for that routine.  This, with dynticks, allows CPUs to be lazy,
allowing them to stay in idle for extended period of time by reducing
unnecesary wakeup and thereby reducing the power consumption.

This patch:

Builds this new timer on top of existing timer infrastructure.  It uses
last bit in 'base' pointer of timer_list structure to store this deferrable
timer flag.  __next_timer_interrupt() function skips over these deferrable
timers when CPU looks for next timer event for which it has to wake up.

This is exported by a new interface init_timer_deferrable() that can be
called in place of regular init_timer().

[akpm@linux-foundation.org: Privatise a #define]
Signed-off-by: Venkatesh Pallipadi 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: Oleg Nesterov 
Cc: Dave Jones 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Add debugging feature /proc/timer_stat

2007-02-16T16:13:59+00:00

Add /proc/timer_stats support: debugging feature to profile timer expiration.
Both the starting site, process/PID and the expiration function is captured.
This allows the quick identification of timer event sources in a system.

Sample output:

# echo 1 > /proc/timer_stats
# cat /proc/timer_stats
Timer Stats Version: v0.1
Sample period: 4.010 s
  24,     0 swapper          hrtimer_stop_sched_tick (hrtimer_sched_tick)
  11,     0 swapper          sk_reset_timer (tcp_delack_timer)
   6,     0 swapper          hrtimer_stop_sched_tick (hrtimer_sched_tick)
   2,     1 swapper          queue_delayed_work_on (delayed_work_timer_fn)
  17,     0 swapper          hrtimer_restart_sched_tick (hrtimer_sched_tick)
   2,     1 swapper          queue_delayed_work_on (delayed_work_timer_fn)
   4,  2050 pcscd            do_nanosleep (hrtimer_wakeup)
   5,  4179 sshd             sk_reset_timer (tcp_write_timer)
   4,  2248 yum-updatesd     schedule_timeout (process_timeout)
  18,     0 swapper          hrtimer_restart_sched_tick (hrtimer_sched_tick)
   3,     0 swapper          sk_reset_timer (tcp_delack_timer)
   1,     1 swapper          neigh_table_init_no_netlink (neigh_periodic_timer)
   2,     1 swapper          e1000_up (e1000_watchdog)
   1,     1 init             schedule_timeout (process_timeout)
100 total events, 25.24 events/sec

[ cleanups and hrtimers support from Thomas Gleixner  ]
[bunk@stusta.de: nr_entries can become static]
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner 
Cc: john stultz 
Cc: Roman Zippel 
Cc: Andi Kleen 
Signed-off-by: Adrian Bunk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] hrtimers: namespace and enum cleanup

2007-02-16T16:13:58+00:00

- hrtimers did not use the hrtimer_restart enum and relied on the implict
  int representation. Fix the prototypes and the functions using the enums.
- Use seperate name spaces for the enumerations
- Convert hrtimer_restart macro to inline function
- Add comments

No functional changes.

[akpm@osdl.org: fix input driver]
Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar 
Cc: john stultz 
Cc: Roman Zippel 
Cc: Dmitry Torokhov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Extend next_timer_interrupt() to use a reference jiffie

2007-02-16T16:13:58+00:00

For CONFIG_NO_HZ we need to calculate the next timer wheel event based on a
given jiffie value.  Extend the existing code to allow the extra 'now'
argument.  Provide a compability function for the existing implementations to
call the function with now == jiffies.  (This also solves the racyness of the
original code vs.  jiffies changing during the iteration.)

No functional changes to existing users of this infrastructure.

[ remove WARN_ON() that triggered on s390, by Carsten Otte  ]
[ made new helper static, Adrian Bunk  ]
Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar 
Cc: john stultz 
Cc: Roman Zippel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] fix various kernel-doc in header files

2007-01-26T21:51:00+00:00

Fix a number of kernel-doc entries for header files in include/linux by
making sure they begin with the appropriate '/**' notation and use @var
notation.

Signed-off-by: Robert P. J. Day 
Signed-off-by: Randy Dunlap 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] round_jiffies infrastructure

2006-12-10T17:57:22+00:00

Introduce a round_jiffies() function as well as a round_jiffies_relative()
function.  These functions round a jiffies value to the next whole second.
The primary purpose of this rounding is to cause all "we don't care exactly
when" timers to happen at the same jiffy.

This avoids multiple timers firing within the second for no real reason;
with dynamic ticks these extra timers cause wakeups from deep sleep CPU
sleep states and thus waste power.

The exact wakeup moment is skewed by the cpu number, to avoid all cpus from
waking up at the exact same time (and hitting the same lock/cachelines
there)

[akpm@osdl.org: fix variable type]
Signed-off-by: Arjan van de Ven 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Don't include linux/config.h from anywhere else in include/

2006-04-26T11:56:16+00:00

Signed-off-by: David Woodhouse