12 Dec, 2011
4 commits
-
Those two APIs were provided to optimize the calls of
tick_nohz_idle_enter() and rcu_idle_enter() into a single
irq disabled section. This way no interrupt happening in-between would
needlessly process any RCU job.Now we are talking about an optimization for which benefits
have yet to be measured. Let's start simple and completely decouple
idle rcu and dyntick idle logics to simplify.Signed-off-by: Frederic Weisbecker
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: Peter Zijlstra
Reviewed-by: Josh Triplett
Signed-off-by: Paul E. McKenney -
It is assumed that rcu won't be used once we switch to tickless
mode and until we restart the tick. However this is not always
true, as in x86-64 where we dereference the idle notifiers after
the tick is stopped.To prepare for fixing this, add two new APIs:
tick_nohz_idle_enter_norcu() and tick_nohz_idle_exit_norcu().If no use of RCU is made in the idle loop between
tick_nohz_enter_idle() and tick_nohz_exit_idle() calls, the arch
must instead call the new *_norcu() version such that the arch doesn't
need to call rcu_idle_enter() and rcu_idle_exit().Otherwise the arch must call tick_nohz_enter_idle() and
tick_nohz_exit_idle() and also call explicitly:- rcu_idle_enter() after its last use of RCU before the CPU is put
to sleep.
- rcu_idle_exit() before the first use of RCU after the CPU is woken
up.Signed-off-by: Frederic Weisbecker
Cc: Mike Frysinger
Cc: Guan Xuetao
Cc: David Miller
Cc: Chris Metcalf
Cc: Hans-Christian Egtvedt
Cc: Ralf Baechle
Cc: Paul E. McKenney
Cc: Ingo Molnar
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: H. Peter Anvin
Cc: Russell King
Cc: Paul Mackerras
Cc: Heiko Carstens
Cc: Paul Mundt
Signed-off-by: Paul E. McKenney -
The tick_nohz_stop_sched_tick() function, which tries to delay
the next timer tick as long as possible, can be called from two
places:- From the idle loop to start the dytick idle mode
- From interrupt exit if we have interrupted the dyntick
idle mode, so that we reprogram the next tick event in
case the irq changed some internal state that requires this
action.There are only few minor differences between both that
are handled by that function, driven by the ts->inidle
cpu variable and the inidle parameter. The whole guarantees
that we only update the dyntick mode on irq exit if we actually
interrupted the dyntick idle mode, and that we enter in RCU extended
quiescent state from idle loop entry only.Split this function into:
- tick_nohz_idle_enter(), which sets ts->inidle to 1, enters
dynticks idle mode unconditionally if it can, and enters into RCU
extended quiescent state.- tick_nohz_irq_exit() which only updates the dynticks idle mode
when ts->inidle is set (ie: if tick_nohz_idle_enter() has been called).To maintain symmetry, tick_nohz_restart_sched_tick() has been renamed
into tick_nohz_idle_exit().This simplifies the code and micro-optimize the irq exit path (no need
for local_irq_save there). This also prepares for the split between
dynticks and rcu extended quiescent state logics. We'll need this split to
further fix illegal uses of RCU in extended quiescent states in the idle
loop.Signed-off-by: Frederic Weisbecker
Cc: Mike Frysinger
Cc: Guan Xuetao
Cc: David Miller
Cc: Chris Metcalf
Cc: Hans-Christian Egtvedt
Cc: Ralf Baechle
Cc: Paul E. McKenney
Cc: Ingo Molnar
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: H. Peter Anvin
Cc: Russell King
Cc: Paul Mackerras
Cc: Heiko Carstens
Cc: Paul Mundt
Signed-off-by: Paul E. McKenney
Reviewed-by: Josh Triplett -
Earlier versions of RCU used the scheduling-clock tick to detect idleness
by checking for the idle task, but handled idleness differently for
CONFIG_NO_HZ=y. But there are now a number of uses of RCU read-side
critical sections in the idle task, for example, for tracing. A more
fine-grained detection of idleness is therefore required.This commit presses the old dyntick-idle code into full-time service,
so that rcu_idle_enter(), previously known as rcu_enter_nohz(), is
always invoked at the beginning of an idle loop iteration. Similarly,
rcu_idle_exit(), previously known as rcu_exit_nohz(), is always invoked
at the end of an idle-loop iteration. This allows the idle task to
use RCU everywhere except between consecutive rcu_idle_enter() and
rcu_idle_exit() calls, in turn allowing architecture maintainers to
specify exactly where in the idle loop that RCU may be used.Because some of the userspace upcall uses can result in what looks
to RCU like half of an interrupt, it is not possible to expect that
the irq_enter() and irq_exit() hooks will give exact counts. This
patch therefore expands the ->dynticks_nesting counter to 64 bits
and uses two separate bitfields to count process/idle transitions
and interrupt entry/exit transitions. It is presumed that userspace
upcalls do not happen in the idle loop or from usermode execution
(though usermode might do a system call that results in an upcall).
The counter is hard-reset on each process/idle transition, which
avoids the interrupt entry/exit error from accumulating. Overflow
is avoided by the 64-bitness of the ->dyntick_nesting counter.This commit also adds warnings if a non-idle task asks RCU to enter
idle state (and these checks will need some adjustment before applying
Frederic's OS-jitter patches (http://lkml.org/lkml/2011/10/7/246).
In addition, validation of ->dynticks and ->dynticks_nesting is added.Signed-off-by: Paul E. McKenney
Signed-off-by: Paul E. McKenney
Reviewed-by: Josh Triplett
10 May, 2010
2 commits
-
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:
Signed-off-by: Ingo Molnar -
Now that the only user of ts->idle_lastupdate is
update_ts_time_stats(), the entire field can be eliminated.In update_ts_time_stats(), idle_lastupdate is first set to
"now", and a few lines later, the only user is an if() statement
that assigns a variable either to "now" or to
ts->idle_lastupdate, which has the value of "now" at that point.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:
Signed-off-by: Ingo Molnar
14 Nov, 2009
1 commit
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The previous patch which limits the sleep time to the maximum
deferment time of the time keeping clocksource has some limitations on
SMP machines: if all CPUs are idle then for all CPUs the maximum sleep
time is limited.Solve this by keeping track of which cpu had the do_timer() duty
assigned last and limit the sleep time only for this cpu.Signed-off-by: Thomas Gleixner
LKML-Reference:
Cc: Jon Hunter
Cc: John Stultz
05 Nov, 2009
1 commit
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Allow the architecture to request a normal jiffy tick when the system
goes idle and tick_nohz_stop_sched_tick is called . On s390 the hook is
used to prevent the system going fully idle if there has been an
interrupt other than a clock comparator interrupt since the last wakeup.On s390 the HiperSockets response time for 1 connection ping-pong goes
down from 42 to 34 microseconds. The CPU cost decreases by 27%.Signed-off-by: Martin Schwidefsky
LKML-Reference:
Signed-off-by: Thomas Gleixner
13 Jun, 2009
1 commit
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commit 3f68535adad (clocksource: sanity check sysfs clocksource
changes) prevents selection of non high resolution capable
clocksources when high resolution mode is active, but did not take
into account that the same rules apply for highres=off nohz=on.Check the tick device mode instead of hrtimer_hres_active() to verify
whether the system needs to be protected from a switch to jiffies or
other non highres capable clock sources.Reported-by: Luming Yu
Signed-off-by: Thomas Gleixner
01 Jan, 2009
1 commit
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Impact: Use new APIs
Convert kernel/time functions to use struct cpumask *.
Note the ugly bitmap declarations in tick-broadcast.c. These should
be cpumask_var_t, but there was no obvious initialization function to
put the alloc_cpumask_var() calls in. This was safe.(Eventually 'struct cpumask' will be undefined for CONFIG_CPUMASK_OFFSTACK,
so we use a bitmap here to show we really mean it).Signed-off-by: Rusty Russell
Signed-off-by: Mike Travis
18 Oct, 2008
1 commit
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We have two separate nohz function calls in irq_enter() for no good
reason. Just call a single NOHZ function from irq_enter() and call
the bits in the tick code.Signed-off-by: Thomas Gleixner
10 Oct, 2008
1 commit
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export get_cpu_idle_time_us() for it to be used in ondemand governor.
Last update time can be current time when the CPU is currently non-idle,
accounting for the busy time since last idle.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Dave Jones
21 Aug, 2008
1 commit
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On the tickless system(CONFIG_NO_HZ=y and CONFIG_HIGH_RES_TIMERS=n), after
I made an offlined cpu online, I found this cpu's event handler was
tick_handle_periodic, not tick_nohz_handler.After debuging, I found this bug was caused by the wrong tick mode. the
tick mode is not changed to NOHZ_MODE_INACTIVE when the cpu is offline.This patch fixes this bug.
Signed-off-by: Miao Xie
Signed-off-by: Andrew Morton
Signed-off-by: Ingo Molnar
19 Jul, 2008
1 commit
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Jack Ren and Eric Miao tracked down the following long standing
problem in the NOHZ code:scheduler switch to idle task
enable interruptsWindow starts here
----> interrupt happens (does not set NEED_RESCHED)
irq_exit() stops the tick----> interrupt happens (does set NEED_RESCHED)
return from schedule()
cpu_idle(): preempt_disable();
Window ends here
The interrupts can happen at any point inside the race window. The
first interrupt stops the tick, the second one causes the scheduler to
rerun and switch away from idle again and we end up with the tick
disabled.The fact that it needs two interrupts where the first one does not set
NEED_RESCHED and the second one does made the bug obscure and extremly
hard to reproduce and analyse. Kudos to Jack and Eric.Solution: Limit the NOHZ functionality to the idle loop to make sure
that we can not run into such a situation ever again.cpu_idle()
{
preempt_disable();while(1) {
tick_nohz_stop_sched_tick(1); ,
Debugged-by: eric miao
Signed-off-by: Thomas Gleixner
02 Feb, 2008
1 commit
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To allow better diagnosis of tick-sched related, especially NOHZ
related problems, we need to know when the last wakeup via an irq
happened and when the CPU left the idle state.Add two fields (idle_waketime, idle_exittime) to the tick_sched
structure and add them to the timer_list output.Signed-off-by: Thomas Gleixner
Signed-off-by: Ingo Molnar
30 Jan, 2008
1 commit
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Current idle time in kstat is based on jiffies and is coarse grained.
tick_sched.idle_sleeptime is making some attempt to keep track of idle time
in a fine grained manner. But, it is not handling the time spent in
interrupts fully.Make tick_sched.idle_sleeptime accurate with respect to time spent on
handling interrupts and also add tick_sched.idle_lastupdate, which keeps
track of last time when idle_sleeptime was updated.This statistics will be crucial for cpufreq-ondemand governor, which can
shed some conservative gaurd band that is uses today while setting the
frequency. The ondemand changes that uses the exact idle time is coming
soon.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Andrew Morton
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
10 Oct, 2007
1 commit
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commit e5a16b1f9eec0af7cfa0830304b41c1c0833cf9f
Author: Len Brown
Date: Tue Oct 2 23:44:44 2007 -0400cpuidle: shrink diff
processor_idle.c | 440 +++++++++++++++++++++++++++++++++++++++++--
1 file changed, 429 insertions(+), 11 deletions(-)Signed-off-by: Len Brown
commit dfbb9d5aedfb18848a3e0d6f6e3e4969febb209c
Author: Len Brown
Date: Wed Sep 26 02:17:55 2007 -0400cpuidle: reduce diff size
Reduces the cpuidle processor_idle.c diff vs 2.6.22 from this
processor_idle.c | 2006 ++++++++++++++++++++++++++-----------------
1 file changed, 1219 insertions(+), 787 deletions(-)to this:
processor_idle.c | 502 +++++++++++++++++++++++++++++++++++++++----
1 file changed, 458 insertions(+), 44 deletions(-)...for the purpose of making the cpuilde patch less invasive
and easier to review.no functional changes. build tested only.
Signed-off-by: Len Brown
commit 889172fc915f5a7fe20f35b133cbd205ce69bf6c
Author: Venki Pallipadi
Date: Thu Sep 13 13:40:05 2007 -0700cpuidle: Retain old ACPI policy for !CONFIG_CPU_IDLE
Retain the old policy in processor_idle, so that when CPU_IDLE is not
configured, old C-state policy will still be used. This provides a
clean gradual migration path from old ACPI policy to new cpuidle
based policy.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Len Browncommit 9544a8181edc7ecc33b3bfd69271571f98ed08bc
Author: Venki Pallipadi
Date: Thu Sep 13 13:39:17 2007 -0700cpuidle: Configure governors by default
Quoting Len "Do not give an option to users to shoot themselves in the foot".
Remove the configurability of ladder and menu governors as they are
needed for default policy of cpuidle. That way users will not be able to
have cpuidle without any policy loosing all C-state power savings.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Len Browncommit 8975059a2c1e56cfe83d1bcf031bcf4cb39be743
Author: Adam Belay
Date: Tue Aug 21 18:27:07 2007 -0400CPUIDLE: load ACPI properly when CPUIDLE is disabled
Change the registration return codes for when CPUIDLE
support is not compiled into the kernel. As a result, the ACPI
processor driver will load properly even if CPUIDLE is unavailable.
However, it may be possible to cleanup the ACPI processor driver further
and eliminate some dead code paths.Signed-off-by: Adam Belay
Acked-by: Venkatesh Pallipadi
Signed-off-by: Len Browncommit e0322e2b58dd1b12ec669bf84693efe0dc2414a8
Author: Adam Belay
Date: Tue Aug 21 18:26:06 2007 -0400CPUIDLE: remove cpuidle_get_bm_activity()
Remove cpuidle_get_bm_activity() and updates governors
accordingly.Signed-off-by: Adam Belay
Acked-by: Venkatesh Pallipadi
Signed-off-by: Len Browncommit 18a6e770d5c82ba26653e53d240caa617e09e9ab
Author: Adam Belay
Date: Tue Aug 21 18:25:58 2007 -0400CPUIDLE: max_cstate fix
Currently max_cstate is limited to 0, resulting in no idle processor
power management on ACPI platforms. This patch restores the value to
the array size.Signed-off-by: Adam Belay
Acked-by: Venkatesh Pallipadi
Signed-off-by: Len Browncommit 1fdc0887286179b40ce24bcdbde663172e205ef0
Author: Adam Belay
Date: Tue Aug 21 18:25:40 2007 -0400CPUIDLE: handle BM detection inside the ACPI Processor driver
Update the ACPI processor driver to detect BM activity and
limit state entry depth internally, rather than exposing such
requirements to CPUIDLE. As a result, CPUIDLE can drop this
ACPI-specific interface and become more platform independent. BM
activity is now handled much more aggressively than it was in the
original implementation, so some testing coverage may be needed to
verify that this doesn't introduce any DMA buffer under-run issues.Signed-off-by: Adam Belay
Acked-by: Venkatesh Pallipadi
Signed-off-by: Len Browncommit 0ef38840db666f48e3cdd2b769da676c57228dd9
Author: Adam Belay
Date: Tue Aug 21 18:25:14 2007 -0400CPUIDLE: menu governor updates
Tweak the menu governor to more effectively handle non-timer
break events. Non-timer break events are detected by comparing the
actual sleep time to the expected sleep time. In future revisions, it
may be more reliable to use the timer data structures directly.Signed-off-by: Adam Belay
Acked-by: Venkatesh Pallipadi
Signed-off-by: Len Browncommit bb4d74fca63fa96cf3ace644b15ae0f12b7df5a1
Author: Adam Belay
Date: Tue Aug 21 18:24:40 2007 -0400CPUIDLE: fix 'current_governor' sysfs entry
Allow the "current_governor" sysfs entry to properly handle
input terminated with '\n'.Signed-off-by: Adam Belay
Acked-by: Venkatesh Pallipadi
Signed-off-by: Len Browncommit df3c71559bb69b125f1a48971bf0d17f78bbdf47
Author: Len Brown
Date: Sun Aug 12 02:00:45 2007 -0400cpuidle: fix IA64 build (again)
Signed-off-by: Len Brown
commit a02064579e3f9530fd31baae16b1fc46b5a7bca8
Author: Venkatesh Pallipadi
Date: Sun Aug 12 01:39:27 2007 -0400cpuidle: Remove support for runtime changing of max_cstate
Remove support for runtime changeability of max_cstate. Drivers can use
use latency APIs.max_cstate can still be used as a boot time option and dmi override.
Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Len Browncommit 0912a44b13adf22f5e3f607d263aed23b4910d7e
Author: Venkatesh Pallipadi
Date: Sun Aug 12 01:39:16 2007 -0400cpuidle: Remove ACPI cstate_limit calls from ipw2100
ipw2100 already has code to use accetable_latency interfaces to limit the
C-state. Remove the calls to acpi_set_cstate_limit and acpi_get_cstate_limit
as they are redundant.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Len Browncommit c649a76e76be6bff1fd770d0a775798813a3f6e0
Author: Venkatesh Pallipadi
Date: Sun Aug 12 01:35:39 2007 -0400cpuidle: compile fix for pause and resume functions
Fix the compilation failure when cpuidle is not compiled in.
Signed-off-by: Venkatesh Pallipadi
Acked-by: Adam Belay
Signed-off-by: Len Browncommit 2305a5920fb8ee6ccec1c62ade05aa8351091d71
Author: Adam Belay
Date: Thu Jul 19 00:49:00 2007 -0400cpuidle: re-write
Some portions have been rewritten to make the code cleaner and lighter
weight. The following is a list of changes:1.) the state name is now included in the sysfs interface
2.) detection, hotplug, and available state modifications are handled by
CPUIDLE drivers directly
3.) the CPUIDLE idle handler is only ever installed when at least one
cpuidle_device is enabled and ready
4.) the menu governor BM code no longer overflows
5.) the sysfs attributes are now printed as unsigned integers, avoiding
negative values
6.) a variety of other small cleanupsAlso, Idle drivers are no longer swappable during runtime through the
CPUIDLE sysfs inteface. On i386 and x86_64 most idle handlers (e.g.
poll, mwait, halt, etc.) don't benefit from an infrastructure that
supports multiple states, so I think using a more general case idle
handler selection mechanism would be cleaner.Signed-off-by: Adam Belay
Acked-by: Venkatesh Pallipadi
Acked-by: Shaohua Li
Signed-off-by: Len Browncommit df25b6b56955714e6e24b574d88d1fd11f0c3ee5
Author: Len Brown
Date: Tue Jul 24 17:08:21 2007 -0400cpuidle: fix IA64 buid
Signed-off-by: Len Brown
commit fd6ada4c14488755ff7068860078c437431fbccd
Author: Adrian Bunk
Date: Mon Jul 9 11:33:13 2007 -0700cpuidle: static
make cpuidle_replace_governor() static
Signed-off-by: Adrian Bunk
Cc: Venkatesh Pallipadi
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit c1d4a2cebcadf2429c0c72e1d29aa2a9684c32e0
Author: Adrian Bunk
Date: Tue Jul 3 00:54:40 2007 -0400cpuidle: static
This patch makes the needlessly global struct menu_governor static.
Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit dbf8780c6e8d572c2c273da97ed1cca7608fd999
Author: Andrew Morton
Date: Tue Jul 3 00:49:14 2007 -0400export symbol tick_nohz_get_sleep_length
ERROR: "tick_nohz_get_sleep_length" [drivers/cpuidle/governors/menu.ko] undefined!
ERROR: "tick_nohz_get_idle_jiffies" [drivers/cpuidle/governors/menu.ko] undefined!And please be sure to get your changes to core kernel suitably reviewed.
Cc: Adam Belay
Cc: Venki Pallipadi
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: john stultz
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit 29f0e248e7017be15f99febf9143a2cef00b2961
Author: Andrew Morton
Date: Tue Jul 3 00:43:04 2007 -0400tick.h needs hrtimer.h
It uses hrtimers.
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit e40cede7d63a029e92712a3fe02faee60cc38fb4
Author: Venki Pallipadi
Date: Tue Jul 3 00:40:34 2007 -0400cpuidle: first round of documentation updates
Documentation changes based on Pavel's feedback.
Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit 83b42be2efece386976507555c29e7773a0dfcd1
Author: Venki Pallipadi
Date: Tue Jul 3 00:39:25 2007 -0400cpuidle: add rating to the governors and pick the one with highest rating by default
Introduce a governor rating scheme to pick the right governor by default.
Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit d2a74b8c5e8f22def4709330d4bfc4a29209b71c
Author: Venki Pallipadi
Date: Tue Jul 3 00:38:08 2007 -0400cpuidle: make cpuidle sysfs driver governor switch off by default
Make default cpuidle sysfs to show current_governor and current_driver in
read-only mode. More elaborate available_governors and available_drivers with
writeable current_governor and current_driver interface only appear with
"cpuidle_sysfs_switch" boot parameter.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit 1f60a0e80bf83cf6b55c8845bbe5596ed8f6307b
Author: Venki Pallipadi
Date: Tue Jul 3 00:37:00 2007 -0400cpuidle: menu governor: change the early break condition
Change the C-state early break out algorithm in menu governor.
We only look at early breakouts that result in wakeups shorter than idle
state's target_residency. If such a breakout is frequent enough, eliminate
the particular idle state upto a timeout period.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit 45a42095cf64b003b4a69be3ce7f434f97d7af51
Author: Venki Pallipadi
Date: Tue Jul 3 00:35:38 2007 -0400cpuidle: fix uninitialized variable in sysfs routine
Fix the uninitialized usage of ret.
Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit 80dca7cdba3e6ee13eae277660873ab9584eb3be
Author: Venki Pallipadi
Date: Tue Jul 3 00:34:16 2007 -0400cpuidle: reenable /proc/acpi//power interface for the time being
Keep /proc/acpi/processor/CPU*/power around for a while as powertop depends
on it. It will be marked deprecated and removed in future. powertop can use
cpuidle interfaces instead.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit 589c37c2646c5e3813a51255a5ee1159cb4c33fc
Author: Venki Pallipadi
Date: Tue Jul 3 00:32:37 2007 -0400cpuidle: menu governor and hrtimer compile fix
Compile fix for menu governor.
Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit 0ba80bd9ab3ed304cb4f19b722e4cc6740588b5e
Author: Len Brown
Date: Thu May 31 22:51:43 2007 -0400cpuidle: build fix - cpuidle vs ipw2100 module
ERROR: "acpi_set_cstate_limit" [drivers/net/wireless/ipw2100.ko] undefined!
Signed-off-by: Len Brown
commit d7d8fa7f96a7f7682be7c6cc0cc53fa7a18c3b58
Author: Adam Belay
Date: Sat Mar 24 03:47:07 2007 -0400cpuidle: add the 'menu' governor
Here is my first take at implementing an idle PM governor that takes
full advantage of NO_HZ. I call it the 'menu' governor because it
considers the full list of idle states before each entry.I've kept the implementation fairly simple. It attempts to guess the
next residency time and then chooses a state that would meet at least
the break-even point between power savings and entry cost. To this end,
it selects the deepest idle state that satisfies the following
constraints:
1. If the idle time elapsed since bus master activity was detected
is below a threshold (currently 20 ms), then limit the selection
to C2-type or above.
2. Do not choose a state with a break-even residency that exceeds
the expected time remaining until the next timer interrupt.
3. Do not choose a state with a break-even residency that exceeds
the elapsed time between the last pair of break events,
excluding timer interrupts.This governor has an advantage over "ladder" governor because it
proactively checks how much time remains until the next timer interrupt
using the tick infrastructure. Also, it handles device interrupt
activity more intelligently by not including timer interrupts in break
event calculations. Finally, it doesn't make policy decisions using the
number of state entries, which can have variable residency times (NO_HZ
makes these potentially very large), and instead only considers sleep
time deltas.The menu governor can be selected during runtime using the cpuidle sysfs
interface like so:
"echo "menu" > /sys/devices/system/cpu/cpuidle/current_governor"Signed-off-by: Adam Belay
Signed-off-by: Len Browncommit a4bec7e65aa3b7488b879d971651cc99a6c410fe
Author: Adam Belay
Date: Sat Mar 24 03:47:03 2007 -0400cpuidle: export time until next timer interrupt using NO_HZ
Expose information about the time remaining until the next
timer interrupt expires by utilizing the dynticks infrastructure.
Also modify the main idle loop to allow dynticks to handle
non-interrupt break events (e.g. DMA). Finally, expose sleep ticks
information to external code. Thomas Gleixner is responsible for much
of the code in this patch. However, I've made some additional changes,
so I'm probably responsible if there are any bugs or oversights :)Signed-off-by: Adam Belay
Signed-off-by: Len Browncommit 2929d8996fbc77f41a5ff86bb67cdde3ca7d2d72
Author: Adam Belay
Date: Sat Mar 24 03:46:58 2007 -0400cpuidle: governor API changes
This patch prepares cpuidle for the menu governor. It adds an optional
stage after idle state entry to give the governor an opportunity to
check why the state was exited. Also it makes sure the idle loop
returns after each state entry, allowing the appropriate dynticks code
to run.Signed-off-by: Adam Belay
Signed-off-by: Len Browncommit 3a7fd42f9825c3b03e364ca59baa751bb350775f
Author: Venki Pallipadi
Date: Thu Apr 26 00:03:59 2007 -0700cpuidle: hang fix
Prevent hang on x86-64, when ACPI processor driver is added as a module on
a system that does not support C-states.x86-64 expects all idle handlers to enable interrupts before returning from
idle handler. This is due to enter_idle(), exit_idle() races. Make
cpuidle_idle_call() confirm to this when there is no pm_idle_old.Also, cpuidle look at the return values of attch_driver() and set
current_driver to NULL if attach fails on all CPUs.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit 4893339a142afbd5b7c01ffadfd53d14746e858e
Author: Shaohua Li
Date: Thu Apr 26 10:40:09 2007 +0800cpuidle: add support for max_cstate limit
With CPUIDLE framework, the max_cstate (to limit max cpu c-state)
parameter is ingored. Some systems require it to ignore C2/C3
and some drivers like ipw require it too.Signed-off-by: Shaohua Li
Signed-off-by: Len Browncommit 43bbbbe1cb998cbd2df656f55bb3bfe30f30e7d1
Author: Shaohua Li
Date: Thu Apr 26 10:40:13 2007 +0800cpuidle: add cpuidle_fore_redetect_devices API
add cpuidle_force_redetect_devices API,
which forces all CPU redetect idle states.
Next patch will use it.Signed-off-by: Shaohua Li
Signed-off-by: Len Browncommit d1edadd608f24836def5ec483d2edccfb37b1d19
Author: Shaohua Li
Date: Thu Apr 26 10:40:01 2007 +0800cpuidle: fix sysfs related issue
Fix the cpuidle sysfs issue.
a. make kobject dynamicaly allocated
b. fixed sysfs init issue to avoid suspend/resume issueSigned-off-by: Shaohua Li
Signed-off-by: Len Browncommit 7169a5cc0d67b263978859672e86c13c23a5570d
Author: Randy Dunlap
Date: Wed Mar 28 22:52:53 2007 -0400cpuidle: 1-bit field must be unsigned
A 1-bit bitfield has no room for a sign bit.
drivers/cpuidle/governors/ladder.c:54:16: error: dubious bitfield without explicit `signed' or `unsigned'Signed-off-by: Randy Dunlap
Cc: Venkatesh Pallipadi
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit 4658620158dc2fbd9e4bcb213c5b6fb5d05ba7d4
Author: Venkatesh Pallipadi
Date: Wed Mar 28 22:52:41 2007 -0400cpuidle: fix boot hang
Patch for cpuidle boot hang reported by Larry Finger here.
http://www.ussg.iu.edu/hypermail/linux/kernel/0703.2/2025.htmlSigned-off-by: Venkatesh Pallipadi
Cc: Larry Finger
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit c17e168aa6e5fe3851baaae8df2fbc1cf11443a9
Author: Len Brown
Date: Wed Mar 7 04:37:53 2007 -0500cpuidle: ladder does not depend on ACPI
build fix for CONFIG_ACPI=n
In file included from drivers/cpuidle/governors/ladder.c:21:
include/acpi/processor.h:88: error: expected specifier-qualifier-list before âacpi_integerâ
include/acpi/processor.h:106: error: expected specifier-qualifier-list before âacpi_integerâ
include/acpi/processor.h:168: error: expected specifier-qualifier-list before âacpi_handleâSigned-off-by: Len Brown
commit 8c91d958246bde68db0c3f0c57b535962ce861cb
Author: Adrian Bunk
Date: Tue Mar 6 02:29:40 2007 -0800cpuidle: make code static
This patch makes the following needlessly global code static:
- driver.c: __cpuidle_find_driver()
- governor.c: __cpuidle_find_governor()
- ladder.c: struct ladder_governorSigned-off-by: Adrian Bunk
Cc: Venkatesh Pallipadi
Cc: Adam Belay
Cc: Shaohua Li
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit 0c39dc3187094c72c33ab65a64d2017b21f372d2
Author: Venkatesh Pallipadi
Date: Wed Mar 7 02:38:22 2007 -0500cpu_idle: fix build break
This patch fixes a build breakage with !CONFIG_HOTPLUG_CPU and
CONFIG_CPU_IDLE.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit 8112e3b115659b07df340ef170515799c0105f82
Author: Venkatesh Pallipadi
Date: Tue Mar 6 02:29:39 2007 -0800cpuidle: build fix for !CPU_IDLE
Fix the compile issues when CPU_IDLE is not configured.
Signed-off-by: Venkatesh Pallipadi
Cc: Adam Belay
Cc: Shaohua Li
Signed-off-by: Andrew Morton
Signed-off-by: Len Browncommit 1eb4431e9599cd25e0d9872f3c2c8986821839dd
Author: Venkatesh Pallipadi
Date: Thu Feb 22 13:54:57 2007 -0800cpuidle take2: Basic documentation for cpuidle
Documentation for cpuidle infrastructure
Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Adam Belay
Signed-off-by: Shaohua Li
Signed-off-by: Len Browncommit ef5f15a8b79123a047285ec2e3899108661df779
Author: Venkatesh Pallipadi
Date: Thu Feb 22 13:54:03 2007 -0800cpuidle take2: Hookup ACPI C-states driver with cpuidle
Hookup ACPI C-states onto generic cpuidle infrastructure.
drivers/acpi/procesor_idle.c is now a ACPI C-states driver that registers as
a driver in cpuidle infrastructure and the policy part is removed from
drivers/acpi/processor_idle.c. We use governor in cpuidle instead.Signed-off-by: Shaohua Li
Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Adam Belay
Signed-off-by: Len Browncommit 987196fa82d4db52c407e8c9d5dec884ba602183
Author: Venkatesh Pallipadi
Date: Thu Feb 22 13:52:57 2007 -0800cpuidle take2: Core cpuidle infrastructure
Announcing 'cpuidle', a new CPU power management infrastructure to manage
idle CPUs in a clean and efficient manner.
cpuidle separates out the drivers that can provide support for multiple types
of idle states and policy governors that decide on what idle state to use
at run time.
A cpuidle driver can support multiple idle states based on parameters like
varying power consumption, wakeup latency, etc (ACPI C-states for example).
A cpuidle governor can be usage model specific (laptop, server,
laptop on battery etc).
Main advantage of the infrastructure being, it allows independent development
of drivers and governors and allows for better CPU power management.A huge thanks to Adam Belay and Shaohua Li who were part of this mini-project
since its beginning and are greatly responsible for this patchset.This patch:
Core cpuidle infrastructure.
Introduces a new abstraction layer for cpuidle:
* which manages drivers that can support multiple idles states. Drivers
can be generic or particular to specific hardware/platform
* allows pluging in multiple policy governors that can take idle state policy
decision
* The core also has a set of sysfs interfaces with which administrato can know
about supported drivers and governors and switch them at run time.Signed-off-by: Adam Belay
Signed-off-by: Shaohua Li
Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Len BrownSigned-off-by: Len Brown
17 Feb, 2007
3 commits
-
add /proc/timer_list, which prints all currently pending (high-res) timers,
all clock-event sources and their parameters in a human-readable form.Sample output:
Timer List Version: v0.1
HRTIMER_MAX_CLOCK_BASES: 2
now at 4246046273872 nsecscpu: 0
clock 0:
.index: 0
.resolution: 1 nsecs
.get_time: ktime_get_real
.offset: 1273998312645738432 nsecs
active timers:
clock 1:
.index: 1
.resolution: 1 nsecs
.get_time: ktime_get
.offset: 0 nsecs
active timers:
#0: , hrtimer_sched_tick, hrtimer_stop_sched_tick, swapper/0
# expires at 4246432689566 nsecs [in 386415694 nsecs]
#1: , hrtimer_wakeup, do_nanosleep, pcscd/2050
# expires at 4247018194689 nsecs [in 971920817 nsecs]
#2: , hrtimer_wakeup, do_nanosleep, irqbalance/1909
# expires at 4247351358392 nsecs [in 1305084520 nsecs]
#3: , hrtimer_wakeup, do_nanosleep, crond/2157
# expires at 4249097614968 nsecs [in 3051341096 nsecs]
#4: , it_real_fn, do_setitimer, syslogd/1888
# expires at 4251329900926 nsecs [in 5283627054 nsecs]
.expires_next : 4246432689566 nsecs
.hres_active : 1
.check_clocks : 0
.nr_events : 31306
.idle_tick : 4246020791890 nsecs
.tick_stopped : 1
.idle_jiffies : 986504
.idle_calls : 40700
.idle_sleeps : 36014
.idle_entrytime : 4246019418883 nsecs
.idle_sleeptime : 4178181972709 nsecscpu: 1
clock 0:
.index: 0
.resolution: 1 nsecs
.get_time: ktime_get_real
.offset: 1273998312645738432 nsecs
active timers:
clock 1:
.index: 1
.resolution: 1 nsecs
.get_time: ktime_get
.offset: 0 nsecs
active timers:
#0: , hrtimer_sched_tick, hrtimer_restart_sched_tick, swapper/0
# expires at 4246050084568 nsecs [in 3810696 nsecs]
#1: , hrtimer_wakeup, do_nanosleep, atd/2227
# expires at 4261010635003 nsecs [in 14964361131 nsecs]
#2: , hrtimer_wakeup, do_nanosleep, smartd/2332
# expires at 5469485798970 nsecs [in 1223439525098 nsecs]
.expires_next : 4246050084568 nsecs
.hres_active : 1
.check_clocks : 0
.nr_events : 24043
.idle_tick : 4246046084568 nsecs
.tick_stopped : 0
.idle_jiffies : 986510
.idle_calls : 26360
.idle_sleeps : 22551
.idle_entrytime : 4246043874339 nsecs
.idle_sleeptime : 4170763761184 nsecstick_broadcast_mask: 00000003
event_broadcast_mask: 00000001CPU#0's local event device:
Clock Event Device: lapic
capabilities: 0000000e
max_delta_ns: 807385544
min_delta_ns: 1443
mult: 44624025
shift: 32
set_next_event: lapic_next_event
set_mode: lapic_timer_setup
event_handler: hrtimer_interrupt
.installed: 1
.expires: 4246432689566 nsecsCPU#1's local event device:
Clock Event Device: lapic
capabilities: 0000000e
max_delta_ns: 807385544
min_delta_ns: 1443
mult: 44624025
shift: 32
set_next_event: lapic_next_event
set_mode: lapic_timer_setup
event_handler: hrtimer_interrupt
.installed: 1
.expires: 4246050084568 nsecsClock Event Device: hpet
capabilities: 00000007
max_delta_ns: 2147483647
min_delta_ns: 3352
mult: 61496110
shift: 32
set_next_event: hpet_next_event
set_mode: hpet_set_mode
event_handler: handle_nextevt_broadcastSigned-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
Cc: john stultz
Cc: Roman Zippel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
With Ingo Molnar
Add functions to provide dynamic ticks and high resolution timers. The code
which keeps track of jiffies and handles the long idle periods is shared
between tick based and high resolution timer based dynticks. The dyntick
functionality can be disabled on the kernel commandline. Provide also the
infrastructure to support high resolution timers.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 -
With Ingo Molnar
The tick-management code is the first user of the clockevents layer. It takes
clock event devices from the clock events core and uses them to provide the
periodic tick.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
