In order to allow better integration between the cpuidle framework and the
scheduler, reducing the distance between these two sub-components will
facilitate this integration by moving part of the cpuidle code in the idle
task file and, because idle.c is in the sched directory, we have access to
the scheduler's private structures.
This patch splits the cpuidle_idle_call main entry function into 3 calls
to a newly added API:
1. select the idle state
2. enter the idle state
3. reflect the idle state
The cpuidle_idle_call calls these three functions to implement the main
idle entry function.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: rjw@rjwysocki.net
Cc: preeti@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1393832934-11625-1-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Some archs set the CPUIDLE_FLAG_TIMER_STOP flag for idle states in which the
local timers stop. The cpuidle_idle_call() currently handles such idle states
by calling into the broadcast framework so as to wakeup CPUs at their next
wakeup event. With the hrtimer mode of broadcast, the BROADCAST_ENTER call
into the broadcast frameowork can fail for archs that do not have an external
clock device to handle wakeups and the CPU in question has thus to be made
the stand by CPU. This patch handles such cases by failing the call into
cpuidle so that the arch can take some default action. The arch will certainly
not enter a similar idle state because a failed cpuidle call will also implicitly
indicate that the broadcast framework has not registered this CPU to be woken up.
Hence we are safe if we fail the cpuidle call.
In the process move the functions that trace idle statistics just before and
after the entry and exit into idle states respectively. In other
scenarios where the call to cpuidle fails, we end up not tracing idle
entry and exit since a decision on an idle state could not be taken. Similarly
when the call to broadcast framework fails, we skip tracing idle statistics
because we are in no further position to take a decision on an alternative
idle state to enter into.
Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: deepthi@linux.vnet.ibm.com
Cc: paulmck@linux.vnet.ibm.com
Cc: fweisbec@gmail.com
Cc: paulus@samba.org
Cc: srivatsa.bhat@linux.vnet.ibm.com
Cc: svaidy@linux.vnet.ibm.com
Cc: peterz@infradead.org
Cc: benh@kernel.crashing.org
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20140207080652.17187.66344.stgit@preeti.in.ibm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If not, we could end up in the unfortunate situation where
we dereference a NULL pointer b/c we have cpuidle disabled.
This is the case when booting under Xen (which uses the
ACPI P/C states but disables the CPU idle driver) - and can
be easily reproduced when booting with cpuidle.off=1.
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff8156db4a>] cpuidle_unregister_device+0x2a/0x90
.. snip..
Call Trace:
[<ffffffff813b15b4>] acpi_processor_power_exit+0x3c/0x5c
[<ffffffff813af0a9>] acpi_processor_stop+0x61/0xb6
[<ffffffff814215bf>] __device_release_driver+0fffff81421653>] device_release_driver+0x23/0x30
[<ffffffff81420ed8>] bus_remove_device+0x108/0x180
[<ffffffff8141d9d9>] device_del+0x129/0x1c0
[<ffffffff813cb4b0>] ? unregister_xenbus_watch+0x1f0/0x1f0
[<ffffffff8141da8e>] device_unregister+0x1e/0x60
[<ffffffff814243e9>] unregister_cpu+0x39/0x60
[<ffffffff81019e03>] arch_unregister_cpu+0x23/0x30
[<ffffffff813c3c51>] handle_vcpu_hotplug_event+0xc1/0xe0
[<ffffffff813cb4f5>] xenwatch_thread+0x45/0x120
[<ffffffff810af010>] ? abort_exclusive_wait+0xb0/0xb0
[<ffffffff8108ec42>] kthread+0xd2/0xf0
[<ffffffff8108eb70>] ? kthread_create_on_node+0x180/0x180
[<ffffffff816ce17c>] ret_from_fork+0x7c/0xb0
[<ffffffff8108eb70>] ? kthread_create_on_node+0x180/0x180
This problem also appears in 3.12 and could be a candidate for backport.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
poll_idle_init() just initializes drv->states[0] and so that is
required to be done only once for each driver. Currently, it is
called from cpuidle_enable_device() which is called for every CPU
that the driver supports. That is not required, so move it to a
better place and call it from __cpuidle_register_driver() so that
the initialization is carried out only once.
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Few statements in cpuidle_idle_call() are broken into multiple lines,
although that isn't really necessary. Convert those to single line.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We are doing this twice in cpuidle_idle_call() routine:
drv->states[next_state].flags & CPUIDLE_FLAG_TIMER_STOP
Would be better if we actually store this in a local variable and
use that. That reduces code duplication and likely makes this piece
of code run faster (in case the compiler wasn't able to optimize it
earlier)
[rjw: Cast the result of bitwise AND to bool explicitly using !!]
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Two checks cpuidle_idle_call() cause the same error code to be
returned if they fail, so merge them for clarity.
[rjw: Changelog]
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch rearranges __cpuidle_register_device() a bit in order to
reduce the number of exit points in that function.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The only value returned by __cpuidle_device_init() is 0, so it very
well may be a void function. Make that happen.
[rjw: Changelog]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Some comments in cpuidle core files contain trivial mistakes.
This patch fixes them.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Make __cpuidle_register_device() check whether or not the device has
been registered already and return -EBUSY immediately if that's the
case.
[rjw: Changelog]
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add __cpuidle_device_init() for initializing the cpuidle_device
structure.
[rjw: Changelog]
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
To reduce code duplication related to the unregistration of cpuidle
devices, introduce __cpuidle_unregister_device() and move all of the
unregistration code to that function.
[rjw: Changelog]
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We previously changed the ordering of the cpuidle framework
initialization so that the governors are registered before the
drivers which can register their devices right from the start.
Now, we can safely remove the __cpuidle_register_device() call hack
in cpuidle_enable_device() and check if the driver has been
registered before enabling it. Then, cpuidle_register_device() can
consistently check the cpuidle_enable_device() return value when
enabling the device.
[rjw: Changelog]
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit bf4d1b5 (cpuidle: support multiple drivers) introduced support
for using multiple cpuidle drivers at the same time. It added a
couple of new APIs to register the driver per CPU, but that led to
some unnecessary code complexity related to the kernel config options
deciding whether or not the multiple driver support is enabled. The
code has to work as it did before when the multiple driver support is
not enabled and the multiple driver support has to be compatible with
the previously existing API.
Remove the new API, not used by any driver in the tree yet (but
needed for the HMP cpuidle drivers that will be submitted soon), and
add a new cpumask pointer to the cpuidle driver structure that will
point to the mask of CPUs handled by the given driver. That will
allow the cpuidle_[un]register_driver() API to be used for the
multiple driver support along with the cpuidle_[un]register()
functions added recently.
[rjw: Changelog]
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Fix comment format for the kernel doc script.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The usual scheme to initialize a cpuidle driver on a SMP is:
cpuidle_register_driver(drv);
for_each_possible_cpu(cpu) {
device = &per_cpu(cpuidle_dev, cpu);
cpuidle_register_device(device);
}
This code is duplicated in each cpuidle driver.
On UP systems, it is done this way:
cpuidle_register_driver(drv);
device = &per_cpu(cpuidle_dev, cpu);
cpuidle_register_device(device);
On UP, the macro 'for_each_cpu' does one iteration:
#define for_each_cpu(cpu, mask) \
for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
Hence, the initialization loop is the same for UP than SMP.
Beside, we saw different bugs / mis-initialization / return code unchecked in
the different drivers, the code is duplicated including bugs. After fixing all
these ones, it appears the initialization pattern is the same for everyone.
Please note, some drivers are doing dev->state_count = drv->state_count. This is
not necessary because it is done by the cpuidle_enable_device function in the
cpuidle framework. This is true, until you have the same states for all your
devices. Otherwise, the 'low level' API should be used instead with the specific
initialization for the driver.
Let's add a wrapper function doing this initialization with a cpumask parameter
for the coupled idle states and use it for all the drivers.
That will save a lot of LOC, consolidate the code, and the modifications in the
future could be done in a single place. Another benefit is the consolidation of
the cpuidle_device variable which is now in the cpuidle framework and no longer
spread accross the different arch specific drivers.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The en_core_tk_irqen flag is set in all the cpuidle driver which
means it is not necessary to specify this flag.
Remove the flag and the code related to it.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org> # for mach-omap2/*
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When a cpu enters a deep idle state, the local timers are stopped and
the time framework falls back to the timer device used as a broadcast
timer.
The different cpuidle drivers are calling clockevents_notify ENTER/EXIT
when the idle state stops the local timer.
Add a new flag CPUIDLE_FLAG_TIMER_STOP which can be set by the cpuidle
drivers. If the flag is set, the cpuidle core code takes care of the
notification on behalf of the driver to avoid pointless code duplication.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The text in Documentation said it would be removed in 2.6.41;
the text in the Kconfig said removal in the 3.1 release. Either
way you look at it, we are well past both, so push it off a cliff.
Note that the POWER_CSTATE and the POWER_PSTATE are part of the
legacy tracing API. Remove all tracepoints which use these flags.
As can be seen from context, most already have a trace entry via
trace_cpu_idle anyways.
Also, the cpufreq/cpufreq.c PSTATE one is actually unpaired, as
compared to the CSTATE ones which all have a clear start/stop.
As part of this, the trace_power_frequency also becomes orphaned,
so it too is deleted.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We realized that the power usage field is never filled and when it
is filled for tegra, the power_specified flag is not set causing all
of these values to be reset when the driver is initialized with
set_power_state().
However, the power_specified flag can be simply removed under the
assumption that the states are always backward sorted, which is the
case with the current code.
This change allows the menu governor select function and the
cpuidle_play_dead() to be simplified. Moreover, the
set_power_states() function can removed as it does not make sense
any more.
Drop the power_specified flag from struct cpuidle_driver and make
the related changes as described above.
As a consequence, this also fixes the bug where on the dynamic
C-states system, the power fields are not initialized.
[rjw: Changelog]
References: https://bugzilla.kernel.org/show_bug.cgi?id=42870
References: https://bugzilla.kernel.org/show_bug.cgi?id=43349
References: https://lkml.org/lkml/2012/10/16/518
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Since cpuidle_state.power_usage is a signed value, use INT_MAX (instead
of -1) to init the local copies so that functions that tries to find
cpuidle states with minimum power usage works correctly even if they use
non-negative values.
Signed-off-by: Sivaram Nair <sivaramn@nvidia.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Many cpuidle drivers measure their time spent in an idle state by
reading the wallclock time before and after idling and calculating the
difference. This leads to erroneous results when the wallclock time gets
updated by another processor in the meantime, adding that clock
adjustment to the idle state's time counter.
If the clock adjustment was negative, the result is even worse due to an
erroneous cast from int to unsigned long long of the last_residency
variable. The negative 32 bit integer will zero-extend and result in a
forward time jump of roughly four billion milliseconds or 1.3 hours on
the idle state residency counter.
This patch changes all affected cpuidle drivers to either use the
monotonic clock for their measurements or make use of the generic time
measurement wrapper in cpuidle.c, which was already working correctly.
Some superfluous CLIs/STIs in the ACPI code are removed (interrupts
should always already be disabled before entering the idle function, and
not get reenabled until the generic wrapper has performed its second
measurement). It also removes the erroneous cast, making sure that
negative residency values are applied correctly even though they should
not appear anymore.
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Tested-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
With the tegra3 and the big.LITTLE [1] new architectures, several cpus
with different characteristics (latencies and states) can co-exists on the
system.
The cpuidle framework has the limitation of handling only identical cpus.
This patch removes this limitation by introducing the multiple driver support
for cpuidle.
This option is configurable at compile time and should be enabled for the
architectures mentioned above. So there is no impact for the other platforms
if the option is disabled. The option defaults to 'n'. Note the multiple drivers
support is also compatible with the existing drivers, even if just one driver is
needed, all the cpu will be tied to this driver using an extra small chunk of
processor memory.
The multiple driver support use a per-cpu driver pointer instead of a global
variable and the accessor to this variable are done from a cpu context.
In order to keep the compatibility with the existing drivers, the function
'cpuidle_register_driver' and 'cpuidle_unregister_driver' will register
the specified driver for all the cpus.
The semantic for the output of /sys/devices/system/cpu/cpuidle/current_driver
remains the same except the driver name will be related to the current cpu.
The /sys/devices/system/cpu/cpu[0-9]/cpuidle/driver/name files are added
allowing to read the per cpu driver name.
[1] http://lwn.net/Articles/481055/
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When cpuidle governor choose a C-state to enter for idle CPU, but it notice that
there is tasks request to be executed. So the idle CPU will not really enter
the target C-state and go to run task.
In this situation, it will use the residency of previous really entered target
C-states. Obviously, it is not reasonable.
So, this patch fix it by set the target C-state residency to 0.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Move the kobj initialization and completion in the sysfs.c
and encapsulate the code more.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The function needs the cpuidle_device which is initially passed to the
caller.
The current code gets the struct device from the struct cpuidle_device,
pass it the cpuidle_add_sysfs function. This function calls
per_cpu(cpuidle_devices, cpu) to get the cpuidle_device.
This patch pass the cpuidle_device instead and simplify the code.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull ACPI & power management update from Len Brown:
"Re-write of the turbostat tool.
lower overhead was necessary for measuring very large system when
they are very idle.
IVB support in intel_idle
It's what I run on my IVB, others should be able to also:-)
ACPICA core update
We have found some bugs due to divergence between Linux and the
upstream ACPICA base. Most of these patches are to reduce that
divergence to reduce the risk of future bugs.
Some cpuidle updates, mostly for non-Intel
More will be coming, as they depend on this part.
Some thermal management changes needed by non-ACPI systems.
Some _OST (OS Status Indication) updates for hot ACPI hot-plug."
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux: (51 commits)
Thermal: Documentation update
Thermal: Add Hysteresis attributes
Thermal: Make Thermal trip points writeable
ACPI/AC: prevent OOPS on some boxes due to missing check power_supply_register() return value check
tools/power: turbostat: fix large c1% issue
tools/power: turbostat v2 - re-write for efficiency
ACPICA: Update to version 20120711
ACPICA: AcpiSrc: Fix some translation issues for Linux conversion
ACPICA: Update header files copyrights to 2012
ACPICA: Add new ACPI table load/unload external interfaces
ACPICA: Split file: tbxface.c -> tbxfload.c
ACPICA: Add PCC address space to space ID decode function
ACPICA: Fix some comment fields
ACPICA: Table manager: deploy new firmware error/warning interfaces
ACPICA: Add new interfaces for BIOS(firmware) errors and warnings
ACPICA: Split exception code utilities to a new file, utexcep.c
ACPI: acpi_pad: tune round_robin_time
ACPICA: Update to version 20120620
ACPICA: Add support for implicit notify on multiple devices
ACPICA: Update comments; no functional change
...
* pm-domains:
PM / Domains: Fix build warning for CONFIG_PM_RUNTIME unset
PM / Domains: Replace plain integer with NULL pointer in domain.c file
PM / Domains: Add missing static storage class specifier in domain.c file
PM / Domains: Allow device callbacks to be added at any time
PM / Domains: Add device domain data reference counter
PM / Domains: Add preliminary support for cpuidle, v2
PM / Domains: Do not stop devices after restoring their states
PM / Domains: Use subsystem runtime suspend/resume callbacks by default
On certain bios, resume hangs if cpus are allowed to enter idle states
during suspend [1].
This was fixed in apci idle driver [2].But intel_idle driver does not
have this fix. Thus instead of replicating the fix in both the idle
drivers, or in more platform specific idle drivers if needed, the
more general cpuidle infrastructure could handle this.
A suspend callback in cpuidle_driver could handle this fix. But
a cpuidle_driver provides only basic functionalities like platform idle
state detection capability and mechanisms to support entry and exit
into CPU idle states. All other cpuidle functions are found in the
cpuidle generic infrastructure for good reason that all cpuidle
drivers, irrepective of their platforms will support these functions.
One option therefore would be to register a suspend callback in cpuidle
which handles this fix. This could be called through a PM_SUSPEND_PREPARE
notifier. But this is too generic a notfier for a driver to handle.
Also, ideally the job of cpuidle is not to handle side effects of suspend.
It should expose the interfaces which "handle cpuidle 'during' suspend"
or any other operation, which the subsystems call during that respective
operation.
The fix demands that during suspend, no cpus should be allowed to enter
deep C-states. The interface cpuidle_uninstall_idle_handler() in cpuidle
ensures that. Not just that it also kicks all the cpus which are already
in idle out of their idle states which was being done during cpu hotplug
through a CPU_DYING_FROZEN callbacks.
Now the question arises about when during suspend should
cpuidle_uninstall_idle_handler() be called. Since we are dealing with
drivers it seems best to call this function during dpm_suspend().
Delaying the call till dpm_suspend_noirq() does no harm, as long as it is
before cpu_hotplug_begin() to avoid race conditions with cpu hotpulg
operations. In dpm_suspend_noirq(), it would be wise to place this call
before suspend_device_irqs() to avoid ugly interactions with the same.
Ananlogously, during resume.
References:
[1] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/674075.
[2] http://marc.info/?l=linux-pm&m=133958534231884&w=2
Reported-and-tested-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
On some systems there are CPU cores located in the same power
domains as I/O devices. Then, power can only be removed from the
domain if all I/O devices in it are not in use and the CPU core
is idle. Add preliminary support for that to the generic PM domains
framework.
First, the platform is expected to provide a cpuidle driver with one
extra state designated for use with the generic PM domains code.
This state should be initially disabled and its exit_latency value
should be set to whatever time is needed to bring up the CPU core
itself after restoring power to it, not including the domain's
power on latency. Its .enter() callback should point to a procedure
that will remove power from the domain containing the CPU core at
the end of the CPU power transition.
The remaining characteristics of the extra cpuidle state, referred to
as the "domain" cpuidle state below, (e.g. power usage, target
residency) should be populated in accordance with the properties of
the hardware.
Next, the platform should execute genpd_attach_cpuidle() on the PM
domain containing the CPU core. That will cause the generic PM
domains framework to treat that domain in a special way such that:
* When all devices in the domain have been suspended and it is about
to be turned off, the states of the devices will be saved, but
power will not be removed from the domain. Instead, the "domain"
cpuidle state will be enabled so that power can be removed from
the domain when the CPU core is idle and the state has been chosen
as the target by the cpuidle governor.
* When the first I/O device in the domain is resumed and
__pm_genpd_poweron(() is called for the first time after
power has been removed from the domain, the "domain" cpuidle
state will be disabled to avoid subsequent surprise power removals
via cpuidle.
The effective exit_latency value of the "domain" cpuidle state
depends on the time needed to bring up the CPU core itself after
restoring power to it as well as on the power on latency of the
domain containing the CPU core. Thus the "domain" cpuidle state's
exit_latency has to be recomputed every time the domain's power on
latency is updated, which may happen every time power is restored
to the domain, if the measured power on latency is greater than
the latency stored in the corresponding generic_pm_domain structure.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Andrew J.Schorr raises a question. When he changes the disable setting on
a single CPU, it affects all the other CPUs. Basically, currently, the
disable field is per-driver instead of per-cpu. All the C states of the
same driver are shared by all CPU in the same machine.
The patch changes the `disable' field to per-cpu, so we could set this
separately for each cpu.
Signed-off-by: ShuoX Liu <shuox.liu@intel.com>
Reported-by: Andrew J.Schorr <aschorr@telemetry-investments.com>
Reviewed-by: Yanmin Zhang <yanmin_zhang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
On some ARM SMP SoCs (OMAP4460, Tegra 2, and probably more), the
cpus cannot be independently powered down, either due to
sequencing restrictions (on Tegra 2, cpu 0 must be the last to
power down), or due to HW bugs (on OMAP4460, a cpu powering up
will corrupt the gic state unless the other cpu runs a work
around). Each cpu has a power state that it can enter without
coordinating with the other cpu (usually Wait For Interrupt, or
WFI), and one or more "coupled" power states that affect blocks
shared between the cpus (L2 cache, interrupt controller, and
sometimes the whole SoC). Entering a coupled power state must
be tightly controlled on both cpus.
The easiest solution to implementing coupled cpu power states is
to hotplug all but one cpu whenever possible, usually using a
cpufreq governor that looks at cpu load to determine when to
enable the secondary cpus. This causes problems, as hotplug is an
expensive operation, so the number of hotplug transitions must be
minimized, leading to very slow response to loads, often on the
order of seconds.
This file implements an alternative solution, where each cpu will
wait in the WFI state until all cpus are ready to enter a coupled
state, at which point the coupled state function will be called
on all cpus at approximately the same time.
Once all cpus are ready to enter idle, they are woken by an smp
cross call. At this point, there is a chance that one of the
cpus will find work to do, and choose not to enter idle. A
final pass is needed to guarantee that all cpus will call the
power state enter function at the same time. During this pass,
each cpu will increment the ready counter, and continue once the
ready counter matches the number of online coupled cpus. If any
cpu exits idle, the other cpus will decrement their counter and
retry.
To use coupled cpuidle states, a cpuidle driver must:
Set struct cpuidle_device.coupled_cpus to the mask of all
coupled cpus, usually the same as cpu_possible_mask if all cpus
are part of the same cluster. The coupled_cpus mask must be
set in the struct cpuidle_device for each cpu.
Set struct cpuidle_device.safe_state to a state that is not a
coupled state. This is usually WFI.
Set CPUIDLE_FLAG_COUPLED in struct cpuidle_state.flags for each
state that affects multiple cpus.
Provide a struct cpuidle_state.enter function for each state
that affects multiple cpus. This function is guaranteed to be
called on all cpus at approximately the same time. The driver
should ensure that the cpus all abort together if any cpu tries
to abort once the function is called.
update1:
cpuidle: coupled: fix count of online cpus
online_count was never incremented on boot, and was also counting
cpus that were not part of the coupled set. Fix both issues by
introducting a new function that counts online coupled cpus, and
call it from register as well as the hotplug notifier.
update2:
cpuidle: coupled: fix decrementing ready count
cpuidle_coupled_set_not_ready sometimes refuses to decrement the
ready count in order to prevent a race condition. This makes it
unsuitable for use when finished with idle. Add a new function
cpuidle_coupled_set_done that decrements both the ready count and
waiting count, and call it after idle is complete.
Cc: Amit Kucheria <amit.kucheria@linaro.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Trinabh Gupta <g.trinabh@gmail.com>
Cc: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
Fix the error handling in __cpuidle_register_device to include
the missing list_del. Move it to a label, which will simplify
the error handling when coupled states are added.
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Colin Cross <ccross@android.com>
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
Split the code to enter a state and update the stats into a helper
function, cpuidle_enter_state, and export it. This function will
be called by the coupled state code to handle entering the safe
state and the final coupled state.
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Colin Cross <ccross@android.com>
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
The existing check for dev == NULL in __cpuidle_register_device() is
rendered useless because dev is dereferenced before the check itself.
Moreover, correctly speaking, it is the job of the callers of this
function, i.e., cpuidle_register_device() & cpuidle_enable_device() (which
also happen to be exported functions) to ensure that
__cpuidle_register_device() is called with a non-NULL dev.
So add the necessary dev == NULL checks in the two callers and remove the
(useless) check from __cpuidle_register_device().
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 9a6558371b
Author: Arjan van de Ven <arjan@linux.intel.com>
Date: Sun Nov 9 12:45:10 2008 -0800
regression: disable timer peek-ahead for 2.6.28
It's showing up as regressions; disabling it very likely just papers
over an underlying issue, but time is running out for 2.6.28, lets get
back to this for 2.6.29
Many years has passed since 2008, so it seems ok to remove whole `#if 0' block.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Trinabh Gupta <g.trinabh@gmail.com>
Cc: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
kick_all_cpus_sync() is the core implementation of cpu_idle_wait()
which is copied all over the arch code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120507175652.119842173@linutronix.de
Fix a NULL pointer dereference panic in cpuidle_play_dead() during
CPU off-lining when no cpuidle driver is registered. A cpuidle
driver may be registered at boot-time based on CPU type. This patch
allows an off-lined CPU to enter HLT-based idle in this condition.
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Cc: Boris Ostrovsky <boris.ostrovsky@amd.com>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Tested-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Pull ACPI & Power Management changes from Len Brown:
- ACPI 5.0 after-ripples, ACPICA/Linux divergence cleanup
- cpuidle evolving, more ARM use
- thermal sub-system evolving, ditto
- assorted other PM bits
Fix up conflicts in various cpuidle implementations due to ARM cpuidle
cleanups (ARM at91 self-refresh and cpu idle code rewritten into
"standby" in asm conflicting with the consolidation of cpuidle time
keeping), trivial SH include file context conflict and RCU tracing fixes
in generic code.
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux: (77 commits)
ACPI throttling: fix endian bug in acpi_read_throttling_status()
Disable MCP limit exceeded messages from Intel IPS driver
ACPI video: Don't start video device until its associated input device has been allocated
ACPI video: Harden video bus adding.
ACPI: Add support for exposing BGRT data
ACPI: export acpi_kobj
ACPI: Fix logic for removing mappings in 'acpi_unmap'
CPER failed to handle generic error records with multiple sections
ACPI: Clean redundant codes in scan.c
ACPI: Fix unprotected smp_processor_id() in acpi_processor_cst_has_changed()
ACPI: consistently use should_use_kmap()
PNPACPI: Fix device ref leaking in acpi_pnp_match
ACPI: Fix use-after-free in acpi_map_lsapic
ACPI: processor_driver: add missing kfree
ACPI, APEI: Fix incorrect APEI register bit width check and usage
Update documentation for parameter *notrigger* in einj.txt
ACPI, APEI, EINJ, new parameter to control trigger action
ACPI, APEI, EINJ, limit the range of einj_param
ACPI, APEI, Fix ERST header length check
cpuidle: power_usage should be declared signed integer
...
Currently when a CPU is off-lined it enters either MWAIT-based idle or,
if MWAIT is not desired or supported, HLT-based idle (which places the
processor in C1 state). This patch allows processors without MWAIT
support to stay in states deeper than C1.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@amd.com>
Signed-off-by: Len Brown <len.brown@intel.com>
If the state_count is not initialized for the device use
the driver's state count as the default. That will prevent
to add it manually in the cpuidle driver initialization
routine and will save us from duplicate line of code.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Some C states of new CPU might be not good. One reason is BIOS might
configure them incorrectly. To help developers root cause it quickly, the
patch adds a new sysfs entry, so developers could disable specific C state
manually.
In addition, C state might have much impact on performance tuning, as it
takes much time to enter/exit C states, which might delay interrupt
processing. With the new debug option, developers could check if a deep C
state could impact performance and how much impact it could cause.
Also add this option in Documentation/cpuidle/sysfs.txt.
[akpm@linux-foundation.org: check kstrtol return value]
Signed-off-by: ShuoX Liu <shuox.liu@intel.com>
Reviewed-by: Yanmin Zhang <yanmin_zhang@intel.com>
Reviewed-and-Tested-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Make necessary changes to implement time keeping and irq enabling
in the core cpuidle code. This will allow the removal of these
functionalities from various platform cpuidle implementations whose
timekeeping and irq enabling follows the form in this common code.
Signed-off-by: Robert Lee <rob.lee@linaro.org>
Tested-by: Jean Pihet <j-pihet@ti.com>
Tested-by: Amit Daniel <amit.kachhap@linaro.org>
Tested-by: Robert Lee <rob.lee@linaro.org>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Len Brown <len.brown@intel.com>
As the tracepoints in the cpuidle code are called when rcu_idle_exit() is in
effect, the _rcuidle() version must be used, otherwise the rcu_read_lock()s
that protect the tracepoint will not be honored.
Cc: Len Brown <len.brown@intel.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This moves the 'cpu sysdev_class' over to a regular 'cpu' subsystem
and converts the devices to regular devices. The sysdev drivers are
implemented as subsystem interfaces now.
After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.
Userspace relies on events and generic sysfs subsystem infrastructure
from sysdev devices, which are made available with this conversion.
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@amd64.org>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Cc: Len Brown <lenb@kernel.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
cpuidle: Single/Global registration of idle states
cpuidle: Split cpuidle_state structure and move per-cpu statistics fields
cpuidle: Remove CPUIDLE_FLAG_IGNORE and dev->prepare()
cpuidle: Move dev->last_residency update to driver enter routine; remove dev->last_state
ACPI: Fix CONFIG_ACPI_DOCK=n compiler warning
ACPI: Export FADT pm_profile integer value to userspace
thermal: Prevent polling from happening during system suspend
ACPI: Drop ACPI_NO_HARDWARE_INIT
ACPI atomicio: Convert width in bits to bytes in __acpi_ioremap_fast()
PNPACPI: Simplify disabled resource registration
ACPI: Fix possible recursive locking in hwregs.c
ACPI: use kstrdup()
mrst pmu: update comment
tools/power turbostat: less verbose debugging
This patch makes the cpuidle_states structure global (single copy)
instead of per-cpu. The statistics needed on per-cpu basis
by the governor are kept per-cpu. This simplifies the cpuidle
subsystem as state registration is done by single cpu only.
Having single copy of cpuidle_states saves memory. Rare case
of asymmetric C-states can be handled within the cpuidle driver
and architectures such as POWER do not have asymmetric C-states.
Having single/global registration of all the idle states,
dynamic C-state transitions on x86 are handled by
the boot cpu. Here, the boot cpu would disable all the devices,
re-populate the states and later enable all the devices,
irrespective of the cpu that would receive the notification first.
Reference:
https://lkml.org/lkml/2011/4/25/83
Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Trinabh Gupta <g.trinabh@gmail.com>
Tested-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This is the first step towards global registration of cpuidle
states. The statistics used primarily by the governor are per-cpu
and have to be split from rest of the fields inside cpuidle_state,
which would be made global i.e. single copy. The driver_data field
is also per-cpu and moved.
Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Trinabh Gupta <g.trinabh@gmail.com>
Tested-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Len Brown <len.brown@intel.com>
The cpuidle_device->prepare() mechanism causes updates to the
cpuidle_state[].flags, setting and clearing CPUIDLE_FLAG_IGNORE
to tell the governor not to chose a state on a per-cpu basis at
run-time. State demotion is now handled by the driver and it returns
the actual state entered. Hence, this mechanism is not required.
Also this removes per-cpu flags from cpuidle_state enabling
it to be made global.
Reference:
https://lkml.org/lkml/2011/3/25/52
Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm>
Signed-off-by: Trinabh Gupta <g.trinabh@gmail.com>
Tested-by: Jean Pihet <j-pihet@ti.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Cpuidle governor only suggests the state to enter using the
governor->select() interface, but allows the low level driver to
override the recommended state. The actual entered state
may be different because of software or hardware demotion. Software
demotion is done by the back-end cpuidle driver and can be accounted
correctly. Current cpuidle code uses last_state field to capture the
actual state entered and based on that updates the statistics for the
state entered.
Ideally the driver enter routine should update the counters,
and it should return the state actually entered rather than the time
spent there. The generic cpuidle code should simply handle where
the counters live in the sysfs namespace, not updating the counters.
Reference:
https://lkml.org/lkml/2011/3/25/52
Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Trinabh Gupta <g.trinabh@gmail.com>
Tested-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Len Brown <len.brown@intel.com>
The PM QoS implementation files are better named
kernel/power/qos.c and include/linux/pm_qos.h.
The PM QoS support is compiled under the CONFIG_PM option.
Signed-off-by: Jean Pihet <j-pihet@ti.com>
Acked-by: markgross <markgross@thegnar.org>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
cpuidle users should call cpuidle_call_idle() directly
rather than via (pm_idle)() function pointer.
Architecture may choose to continue using (pm_idle)(),
but cpuidle need not depend on it:
my_arch_cpu_idle()
...
if(cpuidle_call_idle())
pm_idle();
cc: Kevin Hilman <khilman@deeprootsystems.com>
cc: Paul Mundt <lethal@linux-sh.org>
cc: x86@kernel.org
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
When a Xen Dom0 kernel boots on a hypervisor, it gets access
to the raw-hardware ACPI tables. While it parses the idle tables
for the hypervisor's beneift, it uses HLT for its own idle.
Rather than have xen scribble on pm_idle and access default_idle,
have it simply disable_cpuidle() so acpi_idle will not load and
architecture default HLT will be used.
cc: xen-devel@lists.xensource.com
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
useful for disabling cpuidle to fall back
to architecture-default idle loop
cpuidle drivers and governors will fail to register.
on x86 they'll say so:
intel_idle: intel_idle yielding to (null)
ACPI: acpi_idle yielding to (null)
Signed-off-by: Len Brown <len.brown@intel.com>
Currently intel_idle and acpi_idle driver show double cpu_idle "exit idle"
events -> this patch fixes it and makes cpu_idle events throwing less complex.
It also introduces cpu_idle events for all architectures which use
the cpuidle subsystem, namely:
- arch/arm/mach-at91/cpuidle.c
- arch/arm/mach-davinci/cpuidle.c
- arch/arm/mach-kirkwood/cpuidle.c
- arch/arm/mach-omap2/cpuidle34xx.c
- arch/drivers/acpi/processor_idle.c (for all cases, not only mwait)
- arch/x86/kernel/process.c (did throw events before, but was a mess)
- drivers/idle/intel_idle.c (did throw events before)
Convention should be:
Fire cpu_idle events inside the current pm_idle function (not somewhere
down the the callee tree) to keep things easy.
Current possible pm_idle functions in X86:
c1e_idle, poll_idle, cpuidle_idle_call, mwait_idle, default_idle
-> this is really easy is now.
This affects userspace:
The type field of the cpu_idle power event can now direclty get
mapped to:
/sys/devices/system/cpu/cpuX/cpuidle/stateX/{name,desc,usage,time,...}
instead of throwing very CPU/mwait specific values.
This change is not visible for the intel_idle driver.
For the acpi_idle driver it should only be visible if the vendor
misses out C-states in his BIOS.
Another (perf timechart) patch reads out cpuidle info of cpu_idle
events from:
/sys/.../cpuidle/stateX/*, then the cpuidle events are mapped
to the correct C-/cpuidle state again, even if e.g. vendors miss
out C-states in their BIOS and for example only export C1 and C3.
-> everything is fine.
Signed-off-by: Thomas Renninger <trenn@suse.de>
CC: Robert Schoene <robert.schoene@tu-dresden.de>
CC: Jean Pihet <j-pihet@ti.com>
CC: Arjan van de Ven <arjan@linux.intel.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: linux-pm@lists.linux-foundation.org
CC: linux-acpi@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: linux-perf-users@vger.kernel.org
CC: linux-omap@vger.kernel.org
Signed-off-by: Len Brown <len.brown@intel.com>
C0 means and is well know as "not idle".
All documentation out there uses this term as "running"/"not idle"
state. Also Linux userspace tools (e.g. cpufreq-aperf and turbostat)
show C0 residency which there is correct, but means something totally
else than cpuidle "POLL" state.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
The following scenario is possible with the current cpuidle code and
the ACPI cpuidle driver:
(1) acpi_processor_cst_has_changed() is called,
(2) cpuidle_disable_device() is called,
(3) cpuidle_remove_state_sysfs() is called to remove the (presumably
outdated) states info from sysfs,
(3) acpi_processor_get_power_info() is called, the first entry in the
pr->power.states[] table is filled with zeros,
(4) acpi_processor_setup_cpuidle() is called and it doesn't fill the
first entry in pr->power.states[],
(5) cpuidle_enable_device() is called,
(6) __cpuidle_register_device() is _not_ called, since the device has
already been registered,
(7) Consequently, poll_idle_init() is _not_ called either,
(8) cpuidle_add_state_sysfs() is called to create the sysfs attributes
for the new states and it uses the bogus first table entry from
acpi_processor_get_power_info() for creating state0.
This problem is avoided if cpuidle_enable_device()
unconditionally calls poll_idle_init().
Reported-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
cc: stable@kernel.org
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (30 commits)
gameport: use this_cpu_read instead of lookup
x86: udelay: Use this_cpu_read to avoid address calculation
x86: Use this_cpu_inc_return for nmi counter
x86: Replace uses of current_cpu_data with this_cpu ops
x86: Use this_cpu_ops to optimize code
vmstat: User per cpu atomics to avoid interrupt disable / enable
irq_work: Use per cpu atomics instead of regular atomics
cpuops: Use cmpxchg for xchg to avoid lock semantics
x86: this_cpu_cmpxchg and this_cpu_xchg operations
percpu: Generic this_cpu_cmpxchg() and this_cpu_xchg support
percpu,x86: relocate this_cpu_add_return() and friends
connector: Use this_cpu operations
xen: Use this_cpu_inc_return
taskstats: Use this_cpu_ops
random: Use this_cpu_inc_return
fs: Use this_cpu_inc_return in buffer.c
highmem: Use this_cpu_xx_return() operations
vmstat: Use this_cpu_inc_return for vm statistics
x86: Support for this_cpu_add, sub, dec, inc_return
percpu: Generic support for this_cpu_add, sub, dec, inc_return
...
Fixed up conflicts: in arch/x86/kernel/{apic/nmi.c, apic/x2apic_uv_x.c, process.c}
as per Tejun.
Add these new power trace events:
power:cpu_idle
power:cpu_frequency
power:machine_suspend
The old C-state/idle accounting events:
power:power_start
power:power_end
Have now a replacement (but we are still keeping the old
tracepoints for compatibility):
power:cpu_idle
and
power:power_frequency
is replaced with:
power:cpu_frequency
power:machine_suspend is newly introduced.
Jean Pihet has a patch integrated into the generic layer
(kernel/power/suspend.c) which will make use of it.
the type= field got removed from both, it was never
used and the type is differed by the event type itself.
perf timechart userspace tool gets adjusted in a separate patch.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Jean Pihet <jean.pihet@newoldbits.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: rjw@sisk.pl
LKML-Reference: <1294073445-14812-3-git-send-email-trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1290072314-31155-2-git-send-email-trenn@suse.de>
__get_cpu_var() can be replaced with this_cpu_read and will then use a single
read instruction with implied address calculation to access the correct per cpu
instance.
However, the address of a per cpu variable passed to __this_cpu_read() cannot be
determed (since its an implied address conversion through segment prefixes).
Therefore apply this only to uses of __get_cpu_var where the addres of the
variable is not used.
V3->V4:
- Move one instance of this_cpu_inc_return to a later patch
so that this one can go in without percpu infrastructrure
changes.
Sedat: fixed compile failure caused by an extra ')'.
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
On some SoC chips, HW resources may be in use during any particular idle
period. As a consequence, the cpuidle states that the SoC is safe to
enter can change from idle period to idle period. In addition, the
latency and threshold of each cpuidle state can vary, depending on the
operating condition when the CPU becomes idle, e.g. the current cpu
frequency, the current state of the HW blocks, etc.
cpuidle core and the menu governor, in the current form, are geared
towards cpuidle states that are static, i.e. the availabiltiy of the
states, their latencies, their thresholds are non-changing during run
time. cpuidle does not provide any hook that cpuidle drivers can use to
adjust those values on the fly for the current idle period before the menu
governor selects the target cpuidle state.
This patch extends cpuidle core and the menu governor to handle states
that are dynamic. There are three additions in the patch and the patch
maintains backwards-compatibility with existing cpuidle drivers.
1) add prepare() to struct cpuidle_device. A cpuidle driver can hook
into the callback and cpuidle will call prepare() before calling the
governor's select function. The callback gives the cpuidle driver a
chance to update the dynamic information of the cpuidle states for the
current idle period, e.g. state availability, latencies, thresholds,
power values, etc.
2) add CPUIDLE_FLAG_IGNORE as one of the state flags. In the prepare()
function, a cpuidle driver can set/clear the flag to indicate to the
menu governor whether a cpuidle state should be ignored, i.e. not
available, during the current idle period.
3) add power_specified bit to struct cpuidle_device. The menu governor
currently assumes that the cpuidle states are arranged in the order of
increasing latency, threshold, and power savings. This is true or can
be made true for static states. Once the state parameters are dynamic,
the latencies, thresholds, and power savings for the cpuidle states can
increase or decrease by different amounts from idle period to idle
period. So the assumption of increasing latency, threshold, and power
savings from Cn to C(n+1) can no longer be guaranteed.
It can be straightforward to calculate the power consumption of each
available state and to specify it in power_usage for the idle period.
Using the power_usage fields, the menu governor then selects the state
that has the lowest power consumption and that still satisfies all other
critieria. The power_specified bit defaults to 0. For existing cpuidle
drivers, cpuidle detects that power_specified is 0 and fills in a dummy
set of power_usage values.
Signed-off-by: Ai Li <aili@codeaurora.org>
Cc: Len Brown <len.brown@intel.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
and fix the broken case if a core's frequency depends on others.
trace_power_frequency was only implemented in a rather ungeneric way
in acpi-cpufreq driver's target() function only.
-> Move the call to trace_power_frequency to
cpufreq.c:cpufreq_notify_transition() where CPUFREQ_POSTCHANGE
notifier is triggered.
This will support power frequency tracing by all cpufreq drivers
trace_power_frequency did not trace frequency changes correctly when
the userspace governor was used or when CPU cores' frequency depend
on each other.
-> Moving this into the CPUFREQ_POSTCHANGE notifier and pass the cpu
which gets switched automatically fixes this.
Robert Schoene provided some important fixes on top of my initial
quick shot version which are integrated in this patch:
- Forgot some changes in power_end trace (TP_printk/variable names)
- Variable dummy in power_end must now be cpu_id
- Use static 64 bit variable instead of unsigned int for cpu_id
Signed-off-by: Thomas Renninger <trenn@suse.de>
CC: davej@redhat.com
CC: arjan@infradead.org
CC: linux-kernel@vger.kernel.org
CC: robert.schoene@tu-dresden.de
Tested-by: robert.schoene@tu-dresden.de
Signed-off-by: Dave Jones <davej@redhat.com>
cpuidle_register_driver() sets cpuidle_curr_driver
cpuidle_unregister_driver() clears cpuidle_curr_driver
We should't expose cpuidle_curr_driver to
potential modification except via these interfaces.
So make it static and create cpuidle_get_driver() to observe it.
Signed-off-by: Len Brown <len.brown@intel.com>
In the case where cpuidle_idle_call() returns before changing state due to
a need_resched(), it was returning with IRQs disabled.
The idle path assumes that the platform specific idle code returns with
interrupts enabled (although this too is undocumented AFAICT) and on ARM
we have a WARN_ON(!(irqs_disabled()) when returning from the idle loop, so
the user-visible effects were only a warning since interrupts were
eventually re-enabled later.
On x86, this same problem exists, but there is no WARN_ON() to detect it.
As on ARM, the interrupts are eventually re-enabled, so I'm not sure of
any actual bugs triggered by this. It's primarily a
correctness/consistency fix.
This patch ensures IRQs are (re)enabled before returning.
Reported-by: Hemanth V <hemanthv@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Tested-by: Martin Michlmayr <tbm@cyrius.com>
Cc: <stable@kernel.org> [2.6.31.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The "end of a C state" trace point currently happens before
the code runs that corrects the TSC for having stopped during idle.
The result of this is that the timestamp of the end-of-C-state event
is garbage on cpus where the TSC stops during idle.
This patch moves the end point of the C state to after the timekeeping
engine of the kernel has been corrected.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: fweisbec@gmail.com
Cc: peterz@infradead.org
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20090919133533.139c2a46@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It's showing up as regressions; disabling it very likely just papers
over an underlying issue, but time is running out for 2.6.28, lets get
back to this for 2.6.29
Fixes: #11826 and #11893
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'v28-range-hrtimers-for-linus-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (37 commits)
hrtimers: add missing docbook comments to struct hrtimer
hrtimers: simplify hrtimer_peek_ahead_timers()
hrtimers: fix docbook comments
DECLARE_PER_CPU needs linux/percpu.h
hrtimers: fix typo
rangetimers: fix the bug reported by Ingo for real
rangetimer: fix BUG_ON reported by Ingo
rangetimer: fix x86 build failure for the !HRTIMERS case
select: fix alpha OSF wrapper
select: fix alpha OSF wrapper
hrtimer: peek at the timer queue just before going idle
hrtimer: make the futex() system call use the per process slack value
hrtimer: make the nanosleep() syscall use the per process slack
hrtimer: fix signed/unsigned bug in slack estimator
hrtimer: show the timer ranges in /proc/timer_list
hrtimer: incorporate feedback from Peter Zijlstra
hrtimer: add a hrtimer_start_range() function
hrtimer: another build fix
hrtimer: fix build bug found by Ingo
hrtimer: make select() and poll() use the hrtimer range feature
...
cpuidle accounts the idle time for the C-state it was trying to enter and
not to the actual state that the driver eventually entered. The driver may
select a different state than the one chosen by cpuidle due to
constraints like bus-mastering, etc.
Change the time acounting code to look at the dev->last_state after
returning from target_state->enter(). Driver can modify dev->last_state
internally, inside the enter routine to reflect the actual C-state
entered.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Tested-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Len Brown <len.brown@intel.com>
As part of going idle, we already look at the time of the next timer event to determine
which C-state to select etc.
This patch adds functionality that causes the timers that are past their
soft expire time, to fire at this time, before we calculate the next wakeup
time. This functionality will thus avoid wakeups by running timers before
going idle rather than specially waking up for it.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
pm_idle_save resp. pm_idle_old can be NULL when the restore code in
acpi_processor_cst_has_changed() resp. cpuidle_uninstall_idle_handler()
is called. This can set pm_idle unconditinally to NULL, which causes the
kernel to panic when calling pm_idle in the x86 idle code. This was
covered by an extra check for !pm_idle in the x86 idle code, which was
removed during the x86 idle code refactoring.
Instead of restoring the pm_idle check in the x86 code prevent the
acpi/cpuidle code to set pm_idle to NULL.
Reported by: Dhaval Giani http://lkml.org/lkml/2008/7/2/309
Based on a debug patch from Ingo Molnar
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's never used and the comments refer to nonatomic and retry
interchangably. So get rid of it.
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
cpuidle and acpi driver interaction bug with the way cpuidle_register_driver()
is called. Due to this bug, there will be oops on
AC<->DC on some systems, where they support C-states in one DC and not in AC.
The current code does
ON BOOT:
Look at CST and other C-state info to see whether more than C1 is
supported. If it is, then acpi processor_idle does a
cpuidle_register_driver() call, which internally enables the device.
ON CST change notification (AC<->DC) and on suspend-resume:
acpi driver temporarily disables device, updates the device with
any new C-states, and reenables the device.
The problem is is on boot, there are no C2, C3 states supported and we skip
the register. Later on AC<->DC, we may get a CST notification and we try
to reevaluate CST and enabled the device, without actually registering it.
This causes breakage as we try to create /sys fs sub directory, without the
parent directory which is created at register time.
Thanks to Sanjeev for reporting the problem here.
http://bugzilla.kernel.org/show_bug.cgi?id=10394
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 9b12e18cdc
'ACPI: cpuidle: Support C1 idle time accounting'
was implicated in a 100% C0 idle regression.
http://bugzilla.kernel.org/show_bug.cgi?id=10076
It pointed out a potential problem where the menu governor
may get confused by the C-state residency time from poll
idle or C1 idle, where this timing info is not accurate.
This inaccuracy is due to interrupts being handled
before we account for C-state exit.
Do not mark TIME_VALID for CO poll state.
Mark C1 time as valid only with the MWAIT (CSTATE_FFH) entry method.
This makes governors use the timing information only when it is correct and
eliminates any wrong policy decisions that may result from invalid timing
information.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
cpuidle C-state sysfs node time and usage are very easy to overflow because
they are all of unsigned int type, time will overflow within about two hours,
usage will take longer time to overflow, but they are increasing for ever.
This patch will convert them to unsigned long long.
Signed-off-by: Yi Yang <yi.y.yang@intel.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Add a new sysfs entry under cpuidle states. desc - can be used by driver to
communicate to userspace any specific information about the state.
This helps in identifying the exact hardware C-states behind the ACPI C-state
definition.
Idea is to export this through powertop, which will help to map the C-state
reported by powertop to actual hardware C-state.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
The last posted version of this patch gave compile error
on IA64. So, here goes yet another rewrite of the patch.
Convert cpu_idle_wait() to cpuidle_kick_cpus() which is
SMP-only, and gives error on non supported CPU.
Changes from last patch sent by Kevin:
Moved the definition of kick_cpus back to cpuidle.c from cpuidle.h:
* Having it in .h gives #error on archs which includes the header file without
actually having CPU_IDLE configured. To make it work in .h, we need one more
#ifdef around that code which makes it messy.
* Also, the function is only called from one file. So, it can be in declared
statically in .c rather than making it available to everyone who includes
the .h file.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Add a default poll idle state with 0 latency. Provides an option to users
to use poll_idle by using 0 as the latency requirement.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
The following patch is a generalization of the latency.c implementation done
by Arjan last year. It provides infrastructure for more than one parameter,
and exposes a user mode interface for processes to register pm_qos
expectations of processes.
This interface provides a kernel and user mode interface for registering
performance expectations by drivers, subsystems and user space applications on
one of the parameters.
Currently we have {cpu_dma_latency, network_latency, network_throughput} as
the initial set of pm_qos parameters.
The infrastructure exposes multiple misc device nodes one per implemented
parameter. The set of parameters implement is defined by pm_qos_power_init()
and pm_qos_params.h. This is done because having the available parameters
being runtime configurable or changeable from a driver was seen as too easy to
abuse.
For each parameter a list of performance requirements is maintained along with
an aggregated target value. The aggregated target value is updated with
changes to the requirement list or elements of the list. Typically the
aggregated target value is simply the max or min of the requirement values
held in the parameter list elements.
>From kernel mode the use of this interface is simple:
pm_qos_add_requirement(param_id, name, target_value):
Will insert a named element in the list for that identified PM_QOS
parameter with the target value. Upon change to this list the new target is
recomputed and any registered notifiers are called only if the target value
is now different.
pm_qos_update_requirement(param_id, name, new_target_value):
Will search the list identified by the param_id for the named list element
and then update its target value, calling the notification tree if the
aggregated target is changed. with that name is already registered.
pm_qos_remove_requirement(param_id, name):
Will search the identified list for the named element and remove it, after
removal it will update the aggregate target and call the notification tree
if the target was changed as a result of removing the named requirement.
>From user mode:
Only processes can register a pm_qos requirement. To provide for
automatic cleanup for process the interface requires the process to register
its parameter requirements in the following way:
To register the default pm_qos target for the specific parameter, the
process must open one of /dev/[cpu_dma_latency, network_latency,
network_throughput]
As long as the device node is held open that process has a registered
requirement on the parameter. The name of the requirement is
"process_<PID>" derived from the current->pid from within the open system
call.
To change the requested target value the process needs to write a s32
value to the open device node. This translates to a
pm_qos_update_requirement call.
To remove the user mode request for a target value simply close the device
node.
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: fix build again]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: mark gross <mgross@linux.intel.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Jaroslav Kysela <perex@suse.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Adam Belay <abelay@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert cpu_idle_wait() to cpuidle_kick_cpus() macro which is
SMP-only, and gives error on non supported CPU.
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
This patch removes the following unused exports:
- cpuidle_devices
- cpuidle_register_governor
- cpuidle_unregister_governor
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit e5a16b1f9eec0af7cfa0830304b41c1c0833cf9f
Author: Len Brown <len.brown@intel.com>
Date: Tue Oct 2 23:44:44 2007 -0400
cpuidle: shrink diff
processor_idle.c | 440 +++++++++++++++++++++++++++++++++++++++++--
1 file changed, 429 insertions(+), 11 deletions(-)
Signed-off-by: Len Brown <len.brown@intel.com>
commit dfbb9d5aedfb18848a3e0d6f6e3e4969febb209c
Author: Len Brown <len.brown@intel.com>
Date: Wed Sep 26 02:17:55 2007 -0400
cpuidle: 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 <len.brown@intel.com>
commit 889172fc915f5a7fe20f35b133cbd205ce69bf6c
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Thu Sep 13 13:40:05 2007 -0700
cpuidle: 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 <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 9544a8181edc7ecc33b3bfd69271571f98ed08bc
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Thu Sep 13 13:39:17 2007 -0700
cpuidle: 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 <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 8975059a2c1e56cfe83d1bcf031bcf4cb39be743
Author: Adam Belay <abelay@novell.com>
Date: Tue Aug 21 18:27:07 2007 -0400
CPUIDLE: 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 <abelay@novell.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit e0322e2b58dd1b12ec669bf84693efe0dc2414a8
Author: Adam Belay <abelay@novell.com>
Date: Tue Aug 21 18:26:06 2007 -0400
CPUIDLE: remove cpuidle_get_bm_activity()
Remove cpuidle_get_bm_activity() and updates governors
accordingly.
Signed-off-by: Adam Belay <abelay@novell.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 18a6e770d5c82ba26653e53d240caa617e09e9ab
Author: Adam Belay <abelay@novell.com>
Date: Tue Aug 21 18:25:58 2007 -0400
CPUIDLE: 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 <abelay@novell.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 1fdc0887286179b40ce24bcdbde663172e205ef0
Author: Adam Belay <abelay@novell.com>
Date: Tue Aug 21 18:25:40 2007 -0400
CPUIDLE: 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 <abelay@novell.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 0ef38840db666f48e3cdd2b769da676c57228dd9
Author: Adam Belay <abelay@novell.com>
Date: Tue Aug 21 18:25:14 2007 -0400
CPUIDLE: 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 <abelay@novell.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit bb4d74fca63fa96cf3ace644b15ae0f12b7df5a1
Author: Adam Belay <abelay@novell.com>
Date: Tue Aug 21 18:24:40 2007 -0400
CPUIDLE: fix 'current_governor' sysfs entry
Allow the "current_governor" sysfs entry to properly handle
input terminated with '\n'.
Signed-off-by: Adam Belay <abelay@novell.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit df3c71559bb69b125f1a48971bf0d17f78bbdf47
Author: Len Brown <len.brown@intel.com>
Date: Sun Aug 12 02:00:45 2007 -0400
cpuidle: fix IA64 build (again)
Signed-off-by: Len Brown <len.brown@intel.com>
commit a02064579e3f9530fd31baae16b1fc46b5a7bca8
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Sun Aug 12 01:39:27 2007 -0400
cpuidle: 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 <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 0912a44b13adf22f5e3f607d263aed23b4910d7e
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Sun Aug 12 01:39:16 2007 -0400
cpuidle: 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 <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit c649a76e76be6bff1fd770d0a775798813a3f6e0
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Sun Aug 12 01:35:39 2007 -0400
cpuidle: compile fix for pause and resume functions
Fix the compilation failure when cpuidle is not compiled in.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Adam Belay <adam.belay@novell.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 2305a5920fb8ee6ccec1c62ade05aa8351091d71
Author: Adam Belay <abelay@novell.com>
Date: Thu Jul 19 00:49:00 2007 -0400
cpuidle: 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 cleanups
Also, 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 <abelay@novell.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit df25b6b56955714e6e24b574d88d1fd11f0c3ee5
Author: Len Brown <len.brown@intel.com>
Date: Tue Jul 24 17:08:21 2007 -0400
cpuidle: fix IA64 buid
Signed-off-by: Len Brown <len.brown@intel.com>
commit fd6ada4c14488755ff7068860078c437431fbccd
Author: Adrian Bunk <bunk@stusta.de>
Date: Mon Jul 9 11:33:13 2007 -0700
cpuidle: static
make cpuidle_replace_governor() static
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit c1d4a2cebcadf2429c0c72e1d29aa2a9684c32e0
Author: Adrian Bunk <bunk@stusta.de>
Date: Tue Jul 3 00:54:40 2007 -0400
cpuidle: static
This patch makes the needlessly global struct menu_governor static.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit dbf8780c6e8d572c2c273da97ed1cca7608fd999
Author: Andrew Morton <akpm@linux-foundation.org>
Date: Tue Jul 3 00:49:14 2007 -0400
export 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 <abelay@novell.com>
Cc: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 29f0e248e7017be15f99febf9143a2cef00b2961
Author: Andrew Morton <akpm@linux-foundation.org>
Date: Tue Jul 3 00:43:04 2007 -0400
tick.h needs hrtimer.h
It uses hrtimers.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit e40cede7d63a029e92712a3fe02faee60cc38fb4
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Jul 3 00:40:34 2007 -0400
cpuidle: first round of documentation updates
Documentation changes based on Pavel's feedback.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 83b42be2efece386976507555c29e7773a0dfcd1
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Jul 3 00:39:25 2007 -0400
cpuidle: 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 <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit d2a74b8c5e8f22def4709330d4bfc4a29209b71c
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Jul 3 00:38:08 2007 -0400
cpuidle: 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 <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 1f60a0e80bf83cf6b55c8845bbe5596ed8f6307b
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Jul 3 00:37:00 2007 -0400
cpuidle: 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 <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 45a42095cf64b003b4a69be3ce7f434f97d7af51
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Jul 3 00:35:38 2007 -0400
cpuidle: fix uninitialized variable in sysfs routine
Fix the uninitialized usage of ret.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 80dca7cdba3e6ee13eae277660873ab9584eb3be
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Jul 3 00:34:16 2007 -0400
cpuidle: 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 <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 589c37c2646c5e3813a51255a5ee1159cb4c33fc
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Jul 3 00:32:37 2007 -0400
cpuidle: menu governor and hrtimer compile fix
Compile fix for menu governor.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 0ba80bd9ab3ed304cb4f19b722e4cc6740588b5e
Author: Len Brown <len.brown@intel.com>
Date: Thu May 31 22:51:43 2007 -0400
cpuidle: build fix - cpuidle vs ipw2100 module
ERROR: "acpi_set_cstate_limit" [drivers/net/wireless/ipw2100.ko] undefined!
Signed-off-by: Len Brown <len.brown@intel.com>
commit d7d8fa7f96a7f7682be7c6cc0cc53fa7a18c3b58
Author: Adam Belay <abelay@novell.com>
Date: Sat Mar 24 03:47:07 2007 -0400
cpuidle: 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 <abelay@novell.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit a4bec7e65aa3b7488b879d971651cc99a6c410fe
Author: Adam Belay <abelay@novell.com>
Date: Sat Mar 24 03:47:03 2007 -0400
cpuidle: 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 <abelay@novell.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 2929d8996fbc77f41a5ff86bb67cdde3ca7d2d72
Author: Adam Belay <abelay@novell.com>
Date: Sat Mar 24 03:46:58 2007 -0400
cpuidle: 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 <abelay@novell.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 3a7fd42f9825c3b03e364ca59baa751bb350775f
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Thu Apr 26 00:03:59 2007 -0700
cpuidle: 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 <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 4893339a142afbd5b7c01ffadfd53d14746e858e
Author: Shaohua Li <shaohua.li@intel.com>
Date: Thu Apr 26 10:40:09 2007 +0800
cpuidle: 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 <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 43bbbbe1cb998cbd2df656f55bb3bfe30f30e7d1
Author: Shaohua Li <shaohua.li@intel.com>
Date: Thu Apr 26 10:40:13 2007 +0800
cpuidle: 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 <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit d1edadd608f24836def5ec483d2edccfb37b1d19
Author: Shaohua Li <shaohua.li@intel.com>
Date: Thu Apr 26 10:40:01 2007 +0800
cpuidle: fix sysfs related issue
Fix the cpuidle sysfs issue.
a. make kobject dynamicaly allocated
b. fixed sysfs init issue to avoid suspend/resume issue
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 7169a5cc0d67b263978859672e86c13c23a5570d
Author: Randy Dunlap <randy.dunlap@oracle.com>
Date: Wed Mar 28 22:52:53 2007 -0400
cpuidle: 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 <randy.dunlap@oracle.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 4658620158dc2fbd9e4bcb213c5b6fb5d05ba7d4
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Wed Mar 28 22:52:41 2007 -0400
cpuidle: fix boot hang
Patch for cpuidle boot hang reported by Larry Finger here.
http://www.ussg.iu.edu/hypermail/linux/kernel/0703.2/2025.html
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Larry Finger <larry.finger@lwfinger.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit c17e168aa6e5fe3851baaae8df2fbc1cf11443a9
Author: Len Brown <len.brown@intel.com>
Date: Wed Mar 7 04:37:53 2007 -0500
cpuidle: 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_handleâ
Signed-off-by: Len Brown <len.brown@intel.com>
commit 8c91d958246bde68db0c3f0c57b535962ce861cb
Author: Adrian Bunk <bunk@stusta.de>
Date: Tue Mar 6 02:29:40 2007 -0800
cpuidle: 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_governor
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Adam Belay <abelay@novell.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 0c39dc3187094c72c33ab65a64d2017b21f372d2
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Wed Mar 7 02:38:22 2007 -0500
cpu_idle: fix build break
This patch fixes a build breakage with !CONFIG_HOTPLUG_CPU and
CONFIG_CPU_IDLE.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 8112e3b115659b07df340ef170515799c0105f82
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Mar 6 02:29:39 2007 -0800
cpuidle: build fix for !CPU_IDLE
Fix the compile issues when CPU_IDLE is not configured.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Adam Belay <abelay@novell.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 1eb4431e9599cd25e0d9872f3c2c8986821839dd
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Thu Feb 22 13:54:57 2007 -0800
cpuidle take2: Basic documentation for cpuidle
Documentation for cpuidle infrastructure
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Adam Belay <abelay@novell.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit ef5f15a8b79123a047285ec2e3899108661df779
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Thu Feb 22 13:54:03 2007 -0800
cpuidle 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 <shaohua.li@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Adam Belay <abelay@novell.com>
Signed-off-by: Len Brown <len.brown@intel.com>
commit 987196fa82d4db52c407e8c9d5dec884ba602183
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Thu Feb 22 13:52:57 2007 -0800
cpuidle 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 <abelay@novell.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Daniel Lezcano
Preeti U Murthy
Konrad Rzeszutek Wilk
Viresh Kumar
Paul Gortmaker
Sivaram Nair
Julius Werner
Youquan Song
Srivatsa S. Bhat
Linus Torvalds
Len Brown
Rafael J. Wysocki
ShuoX Liu
Colin Cross
Sergey Senozhatsky
Thomas Gleixner
Toshi Kani
Boris Ostrovsky
Robert Lee
Steven Rostedt
Kay Sievers
Deepthi Dharwar
Jean Pihet
Thomas Renninger
Christoph Lameter
Ai Li
Kevin Hilman
Arjan van de Ven
Arjan van de Ven
Venkatesh Pallipadi
Jens Axboe
Yi Yang
Mark Gross
Kevin Hilman
Adrian Bunk