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path: root/drivers/cpuidle/cpuidle.c
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2014-09-24sched: Let the scheduler see CPU idle statesDaniel Lezcano
When the cpu enters idle, it stores the cpuidle state pointer in its struct rq instance which in turn could be used to make a better decision when balancing tasks. As soon as the cpu exits its idle state, the struct rq reference is cleared. There are a couple of situations where the idle state pointer could be changed while it is being consulted: 1. For x86/acpi with dynamic c-states, when a laptop switches from battery to AC that could result on removing the deeper idle state. The acpi driver triggers: 'acpi_processor_cst_has_changed' 'cpuidle_pause_and_lock' 'cpuidle_uninstall_idle_handler' 'kick_all_cpus_sync'. All cpus will exit their idle state and the pointed object will be set to NULL. 2. The cpuidle driver is unloaded. Logically that could happen but not in practice because the drivers are always compiled in and 95% of them are not coded to unregister themselves. In any case, the unloading code must call 'cpuidle_unregister_device', that calls 'cpuidle_pause_and_lock' leading to 'kick_all_cpus_sync' as mentioned above. A race can happen if we use the pointer and then one of these two scenarios occurs at the same moment. In order to be safe, the idle state pointer stored in the rq must be used inside a rcu_read_lock section where we are protected with the 'rcu_barrier' in the 'cpuidle_uninstall_idle_handler' function. The idle_get_state() and idle_put_state() accessors should be used to that effect. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: linux-pm@vger.kernel.org Cc: linaro-kernel@lists.linaro.org Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-19cpuidle: Use wake_up_all_idle_cpus() to wake up all idle cpusChuansheng Liu
Currently kick_all_cpus_sync() or smp_call_function() can not break the polling idle cpu immediately. Instead using wake_up_all_idle_cpus() which can wake up the polling idle cpu quickly is much more helpful for power. Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: linux-pm@vger.kernel.org Cc: changcheng.liu@intel.com Cc: xiaoming.wang@intel.com Cc: souvik.k.chakravarty@intel.com Cc: luto@amacapital.net Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: linux-pm@vger.kernel.org Link: http://lkml.kernel.org/r/1409815075-4180-3-git-send-email-chuansheng.liu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-09cpuidle: move idle traces to cpuidle_enter_state()Sandeep Tripathy
idle_exit event is the first event after a core exits idle state. So this should be traced before local irq is ebabled. Likewise idle_entry is the last event before a core enters idle state. This will ease visualising the cpu idle state from kernel traces. Signed-off-by: Sandeep Tripathy <sandeep.tripathy@linaro.org> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> [rjw: Subject, rebase] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-07PM / suspend: Always use deepest C-state in the "freeze" sleep stateRafael J. Wysocki
If freeze_enter() is called, we want to bypass the current cpuidle governor and always use the deepest available (that is, not disabled) C-state, because we want to save as much energy as reasonably possible then and runtime latency constraints don't matter at that point, since the system is in a sleep state anyway. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Aubrey Li <aubrey.li@linux.intel.com>
2014-05-01cpuidle: Combine cpuidle_enabled() with cpuidle_select()Rafael J. Wysocki
Since both cpuidle_enabled() and cpuidle_select() are only called by cpuidle_idle_call(), it is not really useful to keep them separate and combining them will help to avoid complicating cpuidle_idle_call() even further if governors are changed to return error codes sometimes. This code modification shouldn't lead to any functional changes. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-02Merge branch 'sched-idle-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull sched/idle changes from Ingo Molnar: "More idle code reorganization, to prepare for more integration. (Sent separately because it depended on pending timer work, which is now upstream)" * 'sched-idle-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/idle: Add more comments to the code sched/idle: Move idle conditions in cpuidle_idle main function sched/idle: Reorganize the idle loop cpuidle/idle: Move the cpuidle_idle_call function to idle.c idle/cpuidle: Split cpuidle_idle_call main function into smaller functions
2014-04-01Merge tag 'pm+acpi-3.15-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management updates from Rafael Wysocki: "The majority of this material spent some time in linux-next, some of it even several weeks. There are a few relatively fresh commits in it, but they are mostly fixes and simple cleanups. ACPI took the lead this time, both in terms of the number of commits and the number of modified lines of code, cpufreq follows and there are a few changes in the PM core and in cpuidle too. A new feature that already got some LWN.net's attention is the device PM QoS extension allowing latency tolerance requirements to be propagated from leaf devices to their ancestors with hardware interfaces for specifying latency tolerance. That should help systems with hardware-driven power management to avoid going too far with it in cases when there are latency tolerance constraints. There also are some significant changes in the ACPI core related to the way in which hotplug notifications are handled. They affect PCI hotplug (ACPIPHP) and the ACPI dock station code too. The bottom line is that all those notification now go through the root notify handler and are propagated to the interested subsystems by means of callbacks instead of having to install a notify handler for each device object that we can potentially get hotplug notifications for. In addition to that ACPICA will now advertise "Windows 2013" compatibility for _OSI, because some systems out there don't work correctly if that is not done (some of them don't even boot). On the system suspend side of things, all of the device suspend and resume callbacks, except for ->prepare() and ->complete(), are now going to be executed asynchronously as that turns out to speed up system suspend and resume on some platforms quite significantly and we have a few more optimizations in that area. Apart from that, there are some new device IDs and fixes and cleanups all over. In particular, the system suspend and resume handling by cpufreq should be improved and the cpuidle menu governor should be a bit more robust now. Specifics: - Device PM QoS support for latency tolerance constraints on systems with hardware interfaces allowing such constraints to be specified. That is necessary to prevent hardware-driven power management from becoming overly aggressive on some systems and to prevent power management features leading to excessive latencies from being used in some cases. - Consolidation of the handling of ACPI hotplug notifications for device objects. This causes all device hotplug notifications to go through the root notify handler (that was executed for all of them anyway before) that propagates them to individual subsystems, if necessary, by executing callbacks provided by those subsystems (those callbacks are associated with struct acpi_device objects during device enumeration). As a result, the code in question becomes both smaller in size and more straightforward and all of those changes should not affect users. - ACPICA update, including fixes related to the handling of _PRT in cases when it is broken and the addition of "Windows 2013" to the list of supported "features" for _OSI (which is necessary to support systems that work incorrectly or don't even boot without it). Changes from Bob Moore and Lv Zheng. - Consolidation of ACPI _OST handling from Jiang Liu. - ACPI battery and AC fixes allowing unusual system configurations to be handled by that code from Alexander Mezin. - New device IDs for the ACPI LPSS driver from Chiau Ee Chew. - ACPI fan and thermal optimizations related to system suspend and resume from Aaron Lu. - Cleanups related to ACPI video from Jean Delvare. - Assorted ACPI fixes and cleanups from Al Stone, Hanjun Guo, Lan Tianyu, Paul Bolle, Tomasz Nowicki. - Intel RAPL (Running Average Power Limits) driver cleanups from Jacob Pan. - intel_pstate fixes and cleanups from Dirk Brandewie. - cpufreq fixes related to system suspend/resume handling from Viresh Kumar. - cpufreq core fixes and cleanups from Viresh Kumar, Stratos Karafotis, Saravana Kannan, Rashika Kheria, Joe Perches. - cpufreq drivers updates from Viresh Kumar, Zhuoyu Zhang, Rob Herring. - cpuidle fixes related to the menu governor from Tuukka Tikkanen. - cpuidle fix related to coupled CPUs handling from Paul Burton. - Asynchronous execution of all device suspend and resume callbacks, except for ->prepare and ->complete, during system suspend and resume from Chuansheng Liu. - Delayed resuming of runtime-suspended devices during system suspend for the PCI bus type and ACPI PM domain. - New set of PM helper routines to allow device runtime PM callbacks to be used during system suspend and resume more easily from Ulf Hansson. - Assorted fixes and cleanups in the PM core from Geert Uytterhoeven, Prabhakar Lad, Philipp Zabel, Rashika Kheria, Sebastian Capella. - devfreq fix from Saravana Kannan" * tag 'pm+acpi-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (162 commits) PM / devfreq: Rewrite devfreq_update_status() to fix multiple bugs PM / sleep: Correct whitespace errors in <linux/pm.h> intel_pstate: Set core to min P state during core offline cpufreq: Add stop CPU callback to cpufreq_driver interface cpufreq: Remove unnecessary braces cpufreq: Fix checkpatch errors and warnings cpufreq: powerpc: add cpufreq transition latency for FSL e500mc SoCs MAINTAINERS: Reorder maintainer addresses for PM and ACPI PM / Runtime: Update runtime_idle() documentation for return value meaning video / output: Drop display output class support fujitsu-laptop: Drop unneeded include acer-wmi: Stop selecting VIDEO_OUTPUT_CONTROL ACPI / gpu / drm: Stop selecting VIDEO_OUTPUT_CONTROL ACPI / video: fix ACPI_VIDEO dependencies cpufreq: remove unused notifier: CPUFREQ_{SUSPENDCHANGE|RESUMECHANGE} cpufreq: Do not allow ->setpolicy drivers to provide ->target cpufreq: arm_big_little: set 'physical_cluster' for each CPU cpufreq: arm_big_little: make vexpress driver depend on bL core driver ACPI / button: Add ACPI Button event via netlink routine ACPI: Remove duplicate definitions of PREFIX ...
2014-03-12cpuidle: delay enabling interrupts until all coupled CPUs leave idlePaul Burton
As described by a comment at the end of cpuidle_enter_state_coupled it can be inefficient for coupled idle states to return with IRQs enabled since they may proceed to service an interrupt instead of clearing the coupled idle state. Until they have finished & cleared the idle state all CPUs coupled with them will spin rather than being able to enter a safe idle state. Commits e1689795a784 "cpuidle: Add common time keeping and irq enabling" and 554c06ba3ee2 "cpuidle: remove en_core_tk_irqen flag" led to the cpuidle_enter_state enabling interrupts for all idle states, including coupled ones, making this inefficiency unavoidable by drivers & the local_irq_enable near the end of cpuidle_enter_state_coupled redundant. This patch avoids enabling interrupts in cpuidle_enter_state after a coupled state has been entered, allowing them to remain disabled until all coupled CPUs have exited the idle state and cpuidle_enter_state_coupled re-enables them. Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-11cpuidle/idle: Move the cpuidle_idle_call function to idle.cDaniel Lezcano
The cpuidle_idle_call does nothing more than calling the three individuals function and is no longer used by any arch specific code but only in the cpuidle framework code. We can move this function into the idle task code to ensure better proximity to the scheduler code. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@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/1393832934-11625-2-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-03-11idle/cpuidle: Split cpuidle_idle_call main function into smaller functionsDaniel Lezcano
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>
2014-02-07cpuidle: Handle clockevents_notify(BROADCAST_ENTER) failurePreeti U Murthy
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>
2013-12-03cpuidle: Check for dev before deregistering it.Konrad Rzeszutek Wilk
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>
2013-10-30cpuidle: don't call poll_idle_init() for every cpuViresh Kumar
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>
2013-10-30cpuidle: replace multiline statements with single line in cpuidle_idle_call()Viresh Kumar
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>
2013-10-30cpuidle: reduce code duplication inside cpuidle_idle_call()Viresh Kumar
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>
2013-10-30cpuidle: merge two if() statements for checking error casesViresh Kumar
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>
2013-10-30cpuidle: rearrange __cpuidle_register_device() to keep minimal exit pointsViresh Kumar
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>
2013-10-30cpuidle: make __cpuidle_device_init() return voidViresh Kumar
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>
2013-10-30cpuidle: Fix comments in cpuidle coreViresh Kumar
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>
2013-07-15cpuidle: Check if device is already registeredDaniel Lezcano
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>
2013-07-15cpuidle: Introduce __cpuidle_device_init()Daniel Lezcano
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>
2013-07-15cpuidle: Introduce __cpuidle_unregister_device()Daniel Lezcano
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>
2013-07-15cpuidle: Check cpuidle_enable_device() return valueDaniel Lezcano
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>
2013-06-11cpuidle: simplify multiple driver supportDaniel Lezcano
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>
2013-04-24cpuidle: fix comment formatDaniel Lezcano
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>
2013-04-23cpuidle: make a single register function for allDaniel Lezcano
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>
2013-04-23cpuidle: remove en_core_tk_irqen flagDaniel Lezcano
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>
2013-04-01cpuidle : handle clockevent notify from the cpuidle frameworkDaniel Lezcano
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>
2013-01-26PM / tracing: remove deprecated power trace APIPaul Gortmaker
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>
2013-01-15cpuidle: remove the power_specified field in the driverDaniel Lezcano
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>
2013-01-03cpuidle: Fix finding state with min power_usageSivaram Nair
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>
2012-11-27cpuidle: Measure idle state durations with monotonic clockJulius Werner
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>
2012-11-15cpuidle: support multiple driversDaniel Lezcano
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>
2012-11-15cpuidle: Set residency to 0 if target Cstate not enterYouquan Song
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>
2012-11-15cpuidle / sysfs: move kobj initialization in the syfs fileDaniel Lezcano
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>
2012-11-15cpuidle / sysfs: change function parameterDaniel Lezcano
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>
2012-10-08ACPI idle, CPU hotplug: Fix NULL pointer dereference during hotplugSrivatsa S. Bhat
On a KVM guest, when a CPU is taken offline and brought back online, we hit the following NULL pointer dereference: [ 45.400843] Unregister pv shared memory for cpu 1 [ 45.412331] smpboot: CPU 1 is now offline [ 45.529894] SMP alternatives: lockdep: fixing up alternatives [ 45.533472] smpboot: Booting Node 0 Processor 1 APIC 0x1 [ 45.411526] kvm-clock: cpu 1, msr 0:7d14601, secondary cpu clock [ 45.571370] KVM setup async PF for cpu 1 [ 45.572331] kvm-stealtime: cpu 1, msr 7d0e040 [ 45.575031] BUG: unable to handle kernel NULL pointer dereference at (null) [ 45.576017] IP: [<ffffffff81519f98>] cpuidle_disable_device+0x18/0x80 [ 45.576017] PGD 5dfb067 PUD 5da8067 PMD 0 [ 45.576017] Oops: 0000 [#1] SMP [ 45.576017] Modules linked in: [ 45.576017] CPU 0 [ 45.576017] Pid: 607, comm: stress_cpu_hotp Not tainted 3.6.0-padata-tp-debug #3 Bochs Bochs [ 45.576017] RIP: 0010:[<ffffffff81519f98>] [<ffffffff81519f98>] cpuidle_disable_device+0x18/0x80 [ 45.576017] RSP: 0018:ffff880005d93ce8 EFLAGS: 00010286 [ 45.576017] RAX: ffff880005d93fd8 RBX: 0000000000000000 RCX: 0000000000000006 [ 45.576017] RDX: 0000000000000006 RSI: 2222222222222222 RDI: 0000000000000000 [ 45.576017] RBP: ffff880005d93cf8 R08: 2222222222222222 R09: 2222222222222222 [ 45.576017] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 45.576017] R13: 0000000000000000 R14: ffffffff81c8cca0 R15: 0000000000000001 [ 45.576017] FS: 00007f91936ae700(0000) GS:ffff880007c00000(0000) knlGS:0000000000000000 [ 45.576017] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 45.576017] CR2: 0000000000000000 CR3: 0000000005db3000 CR4: 00000000000006f0 [ 45.576017] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 45.576017] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 45.576017] Process stress_cpu_hotp (pid: 607, threadinfo ffff880005d92000, task ffff8800066bbf40) [ 45.576017] Stack: [ 45.576017] ffff880007a96400 0000000000000000 ffff880005d93d28 ffffffff813ac689 [ 45.576017] ffff880007a96400 ffff880007a96400 0000000000000002 ffffffff81cd8d01 [ 45.576017] ffff880005d93d58 ffffffff813aa498 0000000000000001 00000000ffffffdd [ 45.576017] Call Trace: [ 45.576017] [<ffffffff813ac689>] acpi_processor_hotplug+0x55/0x97 [ 45.576017] [<ffffffff813aa498>] acpi_cpu_soft_notify+0x93/0xce [ 45.576017] [<ffffffff816ae47d>] notifier_call_chain+0x5d/0x110 [ 45.576017] [<ffffffff8109730e>] __raw_notifier_call_chain+0xe/0x10 [ 45.576017] [<ffffffff81069050>] __cpu_notify+0x20/0x40 [ 45.576017] [<ffffffff81069085>] cpu_notify+0x15/0x20 [ 45.576017] [<ffffffff816978f1>] _cpu_up+0xee/0x137 [ 45.576017] [<ffffffff81697983>] cpu_up+0x49/0x59 [ 45.576017] [<ffffffff8168758d>] store_online+0x9d/0xe0 [ 45.576017] [<ffffffff8140a9f8>] dev_attr_store+0x18/0x30 [ 45.576017] [<ffffffff812322c0>] sysfs_write_file+0xe0/0x150 [ 45.576017] [<ffffffff811b389c>] vfs_write+0xac/0x180 [ 45.576017] [<ffffffff811b3be2>] sys_write+0x52/0xa0 [ 45.576017] [<ffffffff816b31e9>] system_call_fastpath+0x16/0x1b [ 45.576017] Code: 48 c7 c7 40 e5 ca 81 e8 07 d0 18 00 5d c3 0f 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 48 83 ec 10 48 89 5d f0 4c 89 65 f8 48 89 fb <f6> 07 02 75 13 48 8b 5d f0 4c 8b 65 f8 c9 c3 66 0f 1f 84 00 00 [ 45.576017] RIP [<ffffffff81519f98>] cpuidle_disable_device+0x18/0x80 [ 45.576017] RSP <ffff880005d93ce8> [ 45.576017] CR2: 0000000000000000 [ 45.656079] ---[ end trace 433d6c9ac0b02cef ]--- Analysis: Commit 3d339dc (cpuidle / ACPI : move cpuidle_device field out of the acpi_processor_power structure()) made the allocation of the dev structure (struct cpuidle) of a CPU dynamic, whereas previously it was statically allocated. And this dynamic allocation occurs in acpi_processor_power_init() if pr->flags.power evaluates to non-zero. On KVM guests, pr->flags.power evaluates to zero, hence dev is never allocated. This causes the NULL pointer (dev) dereference in cpuidle_disable_device() during a subsequent CPU online operation. Fix this by ensuring that dev is non-NULL before dereferencing. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Len Brown <len.brown@intel.com>
2012-07-26Merge branch 'release' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 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 ...
2012-07-26Merge branches 'acpi_pad', 'acpica', 'apei-bugzilla-43282', 'battery', ↵Len Brown
'cpuidle-coupled', 'cpuidle-tweaks', 'intel_idle-ivb', 'ost', 'red-hat-bz-772730', 'thermal', 'thermal-spear' and 'turbostat-v2' into release
2012-07-19Merge branch 'pm-domains'Rafael J. Wysocki
* 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
2012-07-10PM / cpuidle: System resume hang fix with cpuidlePreeti U Murthy
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>
2012-07-03PM / Domains: Add preliminary support for cpuidle, v2Rafael J. Wysocki
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>
2012-07-03cpuidle: move field disable from per-driver to per-cpuShuoX Liu
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>
2012-06-02cpuidle: add support for states that affect multiple cpusColin Cross
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>
2012-06-02cpuidle: fix error handling in __cpuidle_register_deviceColin Cross
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>
2012-06-02cpuidle: refactor out cpuidle_enter_stateColin Cross
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>
2012-06-01cpuidle: add checks to avoid NULL pointer dereferenceSrivatsa S. Bhat
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>
2012-06-01cpuidle: remove unused hrtimer_peek_ahead_timers() callSergey Senozhatsky
commit 9a6558371bcd01c2973b7638181db4ccc34eab4f 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>
2012-05-08cpuidle: Use kick_all_cpus_sync()Thomas Gleixner
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
2012-04-06Merge branches 'idle-fix' and 'misc' into releaseLen Brown