linux-toradex.git/include/linux/timer.h, branch v2.6.38.6

timer: Make try_to_del_timer_sync() the same on SMP and UP

2010-10-22T12:46:25+00:00

On UP try_to_del_timer_sync() is mapped to del_timer() which does not
take the running timer callback into account, so it has different
semantics.

Remove the SMP dependency of try_to_del_timer_sync() by using
base->running_timer in the UP case as well.

[ tglx: Removed set_running_timer() inline and tweaked the changelog ]

Signed-off-by: Yong Zhang 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Acked-by: Oleg Nesterov 
Signed-off-by: Andrew Morton 
Signed-off-by: Thomas Gleixner

timer: Permit statically-declared work with deferrable timers

2010-10-21T15:30:06+00:00

Currently, you have to just define a delayed_work uninitialised, and then
initialise it before first use.  That's a tad clumsy.  At risk of playing
mind-games with the compiler, fooling it into doing pointer arithmetic
with compile-time-constants, this lets clients properly initialise delayed
work with deferrable timers statically.

This patch was inspired by the issues which lead Artem Bityutskiy to
commit 8eab945c5616fc984 ("sunrpc: make the cache cleaner workqueue
deferrable").

Signed-off-by: Phil Carmody 
Acked-by: Artem Bityutskiy 
Cc: Arjan van de Ven 
Signed-off-by: Andrew Morton 
Signed-off-by: Thomas Gleixner

timer: Initialize the field slack of timer_list

2010-10-21T15:30:06+00:00

TIMER_INITIALIZER() should initialize the field slack of timer_list as
__init_timer() does.

Signed-off-by: Changli Gao 
Cc: Arjan van de Ven 
Signed-off-by: Andrew Morton 
Signed-off-by: Thomas Gleixner

timer_list: Remove alignment padding on 64 bit when CONFIG_TIMER_STATS

2010-10-21T15:30:06+00:00

Reorder struct timer_list to remove 8 bytes of alignment padding on 64
bit builds when CONFIG_TIMER_STATS is selected.

timer_list is widely used across the kernel so many structures will
benefit and shrink in size.

For example, with my config on x86_64
	per_cpu_dm_data shrinks from 136 to 128 bytes
and
	ahci_port_priv shrinks from 1032 to 968 bytes.

Signed-off-by: Richard Kennedy 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Thomas Gleixner

timer: add on-stack deferrable timer interfaces

2010-08-03T13:48:45+00:00

In some cases (for instance with kernel threads) it may be desireable to
use on-stack deferrable timers to get their power saving benefits.  Add
interfaces to support this for the IPS driver.

Signed-off-by: Jesse Barnes 
Signed-off-by: Matthew Garrett

timers: Introduce the concept of timer slack for legacy timers

2010-04-06T19:50:02+00:00

While HR timers have had the concept of timer slack for quite some time
now, the legacy timers lacked this concept, and had to make do with
round_jiffies() and friends.

Timer slack is important for power management; grouping timers reduces the
number of wakeups which in turn reduces power consumption.

This patch introduces timer slack to the legacy timers using the following
pieces:
* A slack field in the timer struct
* An api (set_timer_slack) that callers can use to set explicit timer slack
* A default slack of 0.4% of the requested delay for callers that do not set
  any explicit slack
* Rounding code that is part of mod_timer() that tries to
  group timers around jiffies values every 'power of two'
  (so quick timers will group around every 2, but longer timers
  will group around every 4, 8, 16, 32 etc)

Signed-off-by: Arjan van de Ven 
Cc: johnstul@us.ibm.com
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Thomas Gleixner

timers: Drop a function prototype

2009-08-30T20:26:34+00:00

Drop prototype for non-existent next_timer_interrupt() function.

Signed-off-by: Randy Dunlap 
Cc: akpm 
LKML-Reference: <4A9ADEC0.70306@oracle.com>
Signed-off-by: Thomas Gleixner

timer stats: Optimize by adding quick check to avoid function calls

2009-06-24T09:15:09+00:00

When the kernel is configured with CONFIG_TIMER_STATS but timer
stats are runtime disabled we still get calls to
__timer_stats_timer_set_start_info which initializes some
fields in the corresponding struct timer_list.

So add some quick checks in the the timer stats setup functions
to avoid function calls to __timer_stats_timer_set_start_info
when timer stats are disabled.

In an artificial workload that does nothing but playing ping
pong with a single tcp packet via loopback this decreases cpu
consumption by 1 - 1.5%.

This is part of a modified function trace output on SLES11:

 perl-2497  [00] 28630647177732388 [+  125]: sk_reset_timer <-tcp_v4_rcv
 perl-2497  [00] 28630647177732513 [+  125]: mod_timer <-sk_reset_timer
 perl-2497  [00] 28630647177732638 [+  125]: __timer_stats_timer_set_start_info <-mod_timer
 perl-2497  [00] 28630647177732763 [+  125]: __mod_timer <-mod_timer
 perl-2497  [00] 28630647177732888 [+  125]: __timer_stats_timer_set_start_info <-__mod_timer
 perl-2497  [00] 28630647177733013 [+   93]: lock_timer_base <-__mod_timer

Signed-off-by: Heiko Carstens 
Cc: Andrew Morton 
Cc: Martin Schwidefsky 
Cc: Mustafa Mesanovic 
Cc: Arjan van de Ven 
LKML-Reference: <20090623153811.GA4641@osiris.boeblingen.de.ibm.com>
Signed-off-by: Ingo Molnar

timers: Framework for identifying pinned timers

2009-05-13T14:52:42+00:00

* Arun R Bharadwaj  [2009-04-16 12:11:36]:

This patch creates a new framework for identifying cpu-pinned timers
and hrtimers.

This framework is needed because pinned timers are expected to fire on
the same CPU on which they are queued. So it is essential to identify
these and not migrate them, in case there are any.

For regular timers, the currently existing add_timer_on() can be used
queue pinned timers and subsequently mod_timer_pinned() can be used
to modify the 'expires' field.

For hrtimers, new modes HRTIMER_ABS_PINNED and HRTIMER_REL_PINNED are
added to queue cpu-pinned hrtimer.

[ tglx: use .._PINNED mode argument instead of creating tons of new
functions ]

Signed-off-by: Arun R Bharadwaj 
Signed-off-by: Thomas Gleixner

Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-03-31T00:17:35+00:00

* 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (33 commits)
  lockdep: fix deadlock in lockdep_trace_alloc
  lockdep: annotate reclaim context (__GFP_NOFS), fix SLOB
  lockdep: annotate reclaim context (__GFP_NOFS), fix
  lockdep: build fix for !PROVE_LOCKING
  lockstat: warn about disabled lock debugging
  lockdep: use stringify.h
  lockdep: simplify check_prev_add_irq()
  lockdep: get_user_chars() redo
  lockdep: simplify get_user_chars()
  lockdep: add comments to mark_lock_irq()
  lockdep: remove macro usage from mark_held_locks()
  lockdep: fully reduce mark_lock_irq()
  lockdep: merge the !_READ mark_lock_irq() helpers
  lockdep: merge the _READ mark_lock_irq() helpers
  lockdep: simplify mark_lock_irq() helpers #3
  lockdep: further simplify mark_lock_irq() helpers
  lockdep: simplify the mark_lock_irq() helpers
  lockdep: split up mark_lock_irq()
  lockdep: generate usage strings
  lockdep: generate the state bit definitions
  ...