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2019-07-30cpuidle: add poll_limit_ns to cpuidle_device structureMarcelo Tosatti1-0/+30
Add a poll_limit_ns variable to cpuidle_device structure. Calculate and configure it in the new cpuidle_poll_time function, in case its zero. Individual governors are allowed to override this value. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-04-10cpuidle: Export the next timer expiration for CPUsUlf Hansson1-2/+17
To be able to predict the sleep duration for a CPU entering idle, it is essential to know the expiration time of the next timer. Both the teo and the menu cpuidle governors already use this information for CPU idle state selection. Moving forward, a similar prediction needs to be made for a group of idle CPUs rather than for a single one and the following changes implement a new genpd governor for that purpose. In order to support that feature, add a new function called tick_nohz_get_next_hrtimer() that will return the next hrtimer expiration time of a given CPU to be invoked after deciding whether or not to stop the scheduler tick on that CPU. Make the cpuidle core call tick_nohz_get_next_hrtimer() right before invoking the ->enter() callback provided by the cpuidle driver for the given state and store its return value in the per-CPU struct cpuidle_device, so as to make it available to code outside of cpuidle. Note that at the point when cpuidle calls tick_nohz_get_next_hrtimer(), the governor's ->select() callback has already returned and indicated whether or not the tick should be stopped, so in fact the value returned by tick_nohz_get_next_hrtimer() always is the next hrtimer expiration time for the given CPU, possibly including the tick (if it hasn't been stopped). Co-developed-by: Lina Iyer <lina.iyer@linaro.org> Co-developed-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-12-12cpuidle: Add 'above' and 'below' idle state metricsRafael J. Wysocki1-1/+30
Add two new metrics for CPU idle states, "above" and "below", to count the number of times the given state had been asked for (or entered from the kernel's perspective), but the observed idle duration turned out to be too short or too long for it (respectively). These metrics help to estimate the quality of the CPU idle governor in use. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-12-11cpuidle: Add cpuidle.governor= command line parameterRafael J. Wysocki1-0/+1
Add cpuidle.governor= command line parameter to allow the default cpuidle governor to be replaced. That is useful, for example, if someone running a tickful kernel wants to use the menu governor on it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-09-18cpuidle: enter_state: Don't needlessly calculate diff timeFieah Lim1-8/+8
Currently, ktime_us_delta() is invoked unconditionally to compute the idle residency of the CPU, but it only makes sense to do that if a valid idle state has been entered, so move the ktime_us_delta() invocation after the entered_state >= 0 check. While at it, merge two comment blocks in there into one and drop a space between type casting of diff. This patch has no functional changes. Signed-off-by: Fieah Lim <kw@fieahl.im> [ rjw: Changelog cleanup, comment format fix ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-04-06cpuidle: Return nohz hint from cpuidle_select()Rafael J. Wysocki1-2/+8
Add a new pointer argument to cpuidle_select() and to the ->select cpuidle governor callback to allow a boolean value indicating whether or not the tick should be stopped before entering the selected state to be returned from there. Make the ladder governor ignore that pointer (to preserve its current behavior) and make the menu governor return 'false" through it if: (1) the idle exit latency is constrained at 0, or (2) the selected state is a polling one, or (3) the expected idle period duration is within the tick period range. In addition to that, the correction factor computations in the menu governor need to take the possibility that the tick may not be stopped into account to avoid artificially small correction factor values. To that end, add a mechanism to record tick wakeups, as suggested by Peter Zijlstra, and use it to modify the menu_update() behavior when tick wakeup occurs. Namely, if the CPU is woken up by the tick and the return value of tick_nohz_get_sleep_length() is not within the tick boundary, the predicted idle duration is likely too short, so make menu_update() try to compensate for that by updating the governor statistics as though the CPU was idle for a long time. Since the value returned through the new argument pointer of cpuidle_select() is not used by its caller yet, this change by itself is not expected to alter the functionality of the code. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2018-03-29PM: cpuidle/suspend: Add s2idle usage and time state attributesRafael J. Wysocki1-0/+9
Add a new attribute group called "s2idle" under the sysfs directory of each cpuidle state that supports the ->enter_s2idle callback and put two new attributes, "usage" and "time", into that group to represent the number of times the given state was requested for suspend-to-idle and the total time spent in suspend-to-idle after requesting that state, respectively. That will allow diagnostic information related to suspend-to-idle to be collected without enabling advanced debug features and analyzing dmesg output. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-11-08cpuidle: Avoid assignment in if () argumentGaurav Jindal1-3/+5
Clean up cpuidle_enable_device() to avoid doing an assignment in an expression evaluated as an argument of if (), which also makes the code in question more readable. Signed-off-by: Gaurav Jindal <gauravjindal1104@gmail.com> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-11-08cpuidle: Clean up cpuidle_enable_device() error handling a bitGaurav Jindal1-1/+4
Do not fetch per CPU drv if cpuidle_curr_governor is NULL to avoid useless per CPU processing. Signed-off-by: Gaurav Jindal <gauravjindal1104@gmail.com> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-09-28cpuidle: fix broadcast control when broadcast can not be enteredNicholas Piggin1-0/+1
When failing to enter broadcast timer mode for an idle state that requires it, a new state is selected that does not require broadcast, but the broadcast variable remains set. This causes tick_broadcast_exit to be called despite not having entered broadcast mode. This causes the WARN_ON_ONCE(!irqs_disabled()) to trigger in some cases. It does not appear to cause problems for code today, but seems to violate the interface so should be fixed. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-08-11PM / s2idle: Rename ->enter_freeze to ->enter_s2idleRafael J. Wysocki1-9/+9
Rename the ->enter_freeze cpuidle driver callback to ->enter_s2idle to make it clear that it is used for entering suspend-to-idle and rename the related functions, variables and so on accordingly. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-05-15cpuidle: Fix idle time trackingPeter Zijlstra1-0/+1
Ville reported that on his Core2, which has TSC stop in idle, we would always report very short idle durations. He tracked this down to commit: e93e59ce5b85 ("cpuidle: Replace ktime_get() with local_clock()") which replaces ktime_get() with local_clock(). Add a sched_clock_idle_wakeup_event() call, which will re-sync the clock with ktime_get_ns() when TSC is unstable and no-op otherwise. Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Fixes: e93e59ce5b85 ("cpuidle: Replace ktime_get() with local_clock()") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-01cpuidle: check dev before usage in cpuidle_use_deepest_state()Li, Fei1-1/+2
In case of there is no cpuidle devices registered, dev will be null, and panic will be triggered like below; In this patch, add checking of dev before usage, like that done in cpuidle_idle_call. Panic without fix: [ 184.961328] BUG: unable to handle kernel NULL pointer dereference at (null) [ 184.961328] IP: cpuidle_use_deepest_state+0x30/0x60 ... [ 184.961328] play_idle+0x8d/0x210 [ 184.961328] ? __schedule+0x359/0x8e0 [ 184.961328] ? _raw_spin_unlock_irqrestore+0x28/0x50 [ 184.961328] ? kthread_queue_delayed_work+0x41/0x80 [ 184.961328] clamp_idle_injection_func+0x64/0x1e0 Fixes: bb8313b603eb8 (cpuidle: Allow enforcing deepest idle state selection) Signed-off-by: Li, Fei <fei.li@intel.com> Tested-by: Shi, Feng <fengx.shi@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: 4.10+ <stable@vger.kernel.org> # 4.10+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h>Ingo Molnar1-0/+1
We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which will have to be picked up from other headers and .c files. Create a trivial placeholder <linux/sched/clock.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-06cpuidle: Add a kerneldoc comment to cpuidle_use_deepest_state()Rafael J. Wysocki1-1/+7
Since cpuidle_use_deepest_state() is not static, add a proper kerneldoc comment to it to document its purpose. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-29cpuidle: Allow enforcing deepest idle state selectionJacob Pan1-1/+12
When idle injection is used to cap power, we need to override the governor's choice of idle states. For this reason, make it possible the deepest idle state selection to be enforced by setting a flag on a given CPU to achieve the maximum potential power draw reduction. Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-07-04cpuidle: Fix last_residency divisionShreyas B. Prabhu1-8/+4
Snooze is a poll idle state in powernv and pseries platforms. Snooze has a timeout so that if a CPU stays in snooze for more than target residency of the next available idle state, then it would exit thereby giving chance to the cpuidle governor to re-evaluate and promote the CPU to a deeper idle state. Therefore whenever snooze exits due to this timeout, its last_residency will be target_residency of the next deeper state. Commit e93e59ce5b85 "cpuidle: Replace ktime_get() with local_clock()" changed the math around last_residency calculation. Specifically, while converting last_residency value from nano- to microseconds, it carries out right shift by 10. Because of that, in snooze timeout exit scenarios last_residency calculated is roughly 2.3% less than target_residency of the next available state. This pattern is picked up by get_typical_interval() in the menu governor and therefore expected_interval in menu_select() is frequently less than the target_residency of any state other than snooze. Due to this we are entering snooze at a higher rate, thereby affecting the single thread performance. Fix this by using more precise division via ktime_us_delta(). Fixes: e93e59ce5b85 "cpuidle: Replace ktime_get() with local_clock()" Reported-by: Anton Blanchard <anton@samba.org> Bisected-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-05-18cpuidle: Fix cpuidle_state_is_coupled() argument in cpuidle_enter()Daniel Lezcano1-1/+1
Commit 0b89e9aa2856 (cpuidle: delay enabling interrupts until all coupled CPUs leave idle) rightfully fixed a regression by letting the coupled idle state framework to handle local interrupt enabling when the CPU is exiting an idle state. The current code checks if the idle state is coupled and, if so, it will let the coupled code to enable interrupts. This way, it can decrement the ready-count before handling the interrupt. This mechanism prevents the other CPUs from waiting for a CPU which is handling interrupts. But the check is done against the state index returned by the back end driver's ->enter functions which could be different from the initial index passed as parameter to the cpuidle_enter_state() function. entered_state = target_state->enter(dev, drv, index); [ ... ] if (!cpuidle_state_is_coupled(drv, entered_state)) local_irq_enable(); [ ... ] If the 'index' is referring to a coupled idle state but the 'entered_state' is *not* coupled, then the interrupts are enabled again. All CPUs blocked on the sync barrier may busy loop longer if the CPU has interrupts to handle before decrementing the ready-count. That's consuming more energy than saving. Fixes: 0b89e9aa2856 (cpuidle: delay enabling interrupts until all coupled CPUs leave idle) Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: 3.15+ <stable@vger.kernel.org> # 3.15+ [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-26cpuidle: Replace ktime_get() with local_clock()Daniel Lezcano1-4/+8
The ktime_get() can have a non negligeable overhead, use local_clock() instead. In order to test the difference between ktime_get() and local_clock(), a quick hack has been added to trigger, via debugfs, 10000 times a call to ktime_get() and local_clock() and measure the elapsed time. Then the average value, the min and max is computed for each call. From userspace, the test above was called 100 times every 2 seconds. So, ktime_get() and local_clock() have been called 1000000 times in total. The results are: ktime_get(): ============ * average: 101 ns (stddev: 27.4) * maximum: 38313 ns * minimum: 65 ns local_clock(): ============== * average: 60 ns (stddev: 9.8) * maximum: 13487 ns * minimum: 46 ns The local_clock() is faster and more stable. Even if it is a drop in the ocean, changing the ktime_get() by the local_clock() allows to save 80ns at idle time (entry + exit). And in some circumstances, especially when there are several CPUs racing for the clock access, we save tens of microseconds. The idle duration resulting from a diff is converted from nanosec to microsec. This could be done with integer division (div 1000) - which is an expensive operation or by 10 bits shifting (div 1024) - which is fast but unprecise. The following table gives some results at the limits. ------------------------------------------ | nsec | div(1000) | div(1024) | ------------------------------------------ | 1e3 | 1 usec | 976 nsec | ------------------------------------------ | 1e6 | 1000 usec | 976 usec | ------------------------------------------ | 1e9 | 1000000 usec | 976562 usec | ------------------------------------------ There is a linear deviation of 2.34%. This loss of precision is acceptable in the context of the resulting diff which is used for statistics. These ones are processed to guess estimate an approximation of the duration of the next idle period which ends up into an idle state selection. The selection criteria takes into account the next duration based on large intervals, represented by the idle state's target residency. The 2^10 division is enough because the approximation regarding the 1e3 division is lost in all the approximations done for the next idle duration computation. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-09cpuidle: Indicate when a device has been unregisteredDave Gerlach1-0/+2
Currently the 'registered' member of the cpuidle_device struct is set to 1 during cpuidle_register_device. In this same function there are checks to see if the device is already registered to prevent duplicate calls to register the device, but this value is never set to 0 even on unregister of the device. Because of this, any attempt to call cpuidle_register_device after a call to cpuidle_unregister_device will fail which shouldn't be the case. To prevent this, set registered to 0 when the device is unregistered. Fixes: c878a52d3c7c (cpuidle: Check if device is already registered) Signed-off-by: Dave Gerlach <d-gerlach@ti.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-01-22cpuidle: fix fallback mechanism for suspend to idle in absence of enter_freezeSudeep Holla1-1/+1
Commit 51164251f5c3 "sched / idle: Drop default_idle_call() fallback from call_cpuidle()" made find_deepest_state() return non-negative value and check all the states with index > 0. Also as a result, find_deepest_state() returns 0 even when enter_freeze callbacks are not implemented and enter_freeze_proper() is called which ends up crashing the kernel. This patch updates the check for index > 0 in cpuidle_enter_freeze and cpuidle_idle_call(when idle_should_freeze is true) to restore the suspend-to-idle functionality in absence of enter_freeze callback. Fixes: 51164251f5c3 "sched / idle: Drop default_idle_call() fallback from call_cpuidle()" Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-01-19sched / idle: Drop default_idle_call() fallback from call_cpuidle()Rafael J. Wysocki1-3/+3
After commit 9c4b2867ed7c (cpuidle: menu: Fix menu_select() for CPUIDLE_DRIVER_STATE_START == 0) it is clear that menu_select() cannot return negative values. Moreover, ladder_select_state() will never return a negative value too, so make find_deepest_state() return non-negative values too and drop the default_idle_call() fallback from call_cpuidle(). This eliminates one branch from the idle loop and makes the governors and find_deepest_state() handle the case when all states have been disabled from sysfs consistently. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@kernel.org> Tested-by: Sudeep Holla <sudeep.holla@arm.com>
2015-09-01Merge tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds1-2/+2
Pull power management and ACPI updates from Rafael Wysocki: "From the number of commits perspective, the biggest items are ACPICA and cpufreq changes with the latter taking the lead (over 50 commits). On the cpufreq front, there are many cleanups and minor fixes in the core and governors, driver updates etc. We also have a new cpufreq driver for Mediatek MT8173 chips. ACPICA mostly updates its debug infrastructure and adds a number of fixes and cleanups for a good measure. The Operating Performance Points (OPP) framework is updated with new DT bindings and support for them among other things. We have a few updates of the generic power domains framework and a reorganization of the ACPI device enumeration code and bus type operations. And a lot of fixes and cleanups all over. Included is one branch from the MFD tree as it contains some PM-related driver core and ACPI PM changes a few other commits are based on. Specifics: - ACPICA update to upstream revision 20150818 including method tracing extensions to allow more in-depth AML debugging in the kernel and a number of assorted fixes and cleanups (Bob Moore, Lv Zheng, Markus Elfring). - ACPI sysfs code updates and a documentation update related to AML method tracing (Lv Zheng). - ACPI EC driver fix related to serialized evaluations of _Qxx methods and ACPI tools updates allowing the EC userspace tool to be built from the kernel source (Lv Zheng). - ACPI processor driver updates preparing it for future introduction of CPPC support and ACPI PCC mailbox driver updates (Ashwin Chaugule). - ACPI interrupts enumeration fix for a regression related to the handling of IRQ attribute conflicts between MADT and the ACPI namespace (Jiang Liu). - Fixes related to ACPI device PM (Mika Westerberg, Srinidhi Kasagar). - ACPI device registration code reorganization to separate the sysfs-related code and bus type operations from the rest (Rafael J Wysocki). - Assorted cleanups in the ACPI core (Jarkko Nikula, Mathias Krause, Andy Shevchenko, Rafael J Wysocki, Nicolas Iooss). - ACPI cpufreq driver and ia64 cpufreq driver fixes and cleanups (Pan Xinhui, Rafael J Wysocki). - cpufreq core cleanups on top of the previous changes allowing it to preseve its sysfs directories over system suspend/resume (Viresh Kumar, Rafael J Wysocki, Sebastian Andrzej Siewior). - cpufreq fixes and cleanups related to governors (Viresh Kumar). - cpufreq updates (core and the cpufreq-dt driver) related to the turbo/boost mode support (Viresh Kumar, Bartlomiej Zolnierkiewicz). - New DT bindings for Operating Performance Points (OPP), support for them in the OPP framework and in the cpufreq-dt driver plus related OPP framework fixes and cleanups (Viresh Kumar). - cpufreq powernv driver updates (Shilpasri G Bhat). - New cpufreq driver for Mediatek MT8173 (Pi-Cheng Chen). - Assorted cpufreq driver (speedstep-lib, sfi, integrator) cleanups and fixes (Abhilash Jindal, Andrzej Hajda, Cristian Ardelean). - intel_pstate driver updates including Skylake-S support, support for enabling HW P-states per CPU and an additional vendor bypass list entry (Kristen Carlson Accardi, Chen Yu, Ethan Zhao). - cpuidle core fixes related to the handling of coupled idle states (Xunlei Pang). - intel_idle driver updates including Skylake Client support and support for freeze-mode-specific idle states (Len Brown). - Driver core updates related to power management (Andy Shevchenko, Rafael J Wysocki). - Generic power domains framework fixes and cleanups (Jon Hunter, Geert Uytterhoeven, Rajendra Nayak, Ulf Hansson). - Device PM QoS framework update to allow the latency tolerance setting to be exposed to user space via sysfs (Mika Westerberg). - devfreq support for PPMUv2 in Exynos5433 and a fix for an incorrect exynos-ppmu DT binding (Chanwoo Choi, Javier Martinez Canillas). - System sleep support updates (Alan Stern, Len Brown, SungEun Kim). - rockchip-io AVS support updates (Heiko Stuebner). - PM core clocks support fixup (Colin Ian King). - Power capping RAPL driver update including support for Skylake H/S and Broadwell-H (Radivoje Jovanovic, Seiichi Ikarashi). - Generic device properties framework fixes related to the handling of static (driver-provided) property sets (Andy Shevchenko). - turbostat and cpupower updates (Len Brown, Shilpasri G Bhat, Shreyas B Prabhu)" * tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (180 commits) cpufreq: speedstep-lib: Use monotonic clock cpufreq: powernv: Increase the verbosity of OCC console messages cpufreq: sfi: use kmemdup rather than duplicating its implementation cpufreq: drop !cpufreq_driver check from cpufreq_parse_governor() cpufreq: rename cpufreq_real_policy as cpufreq_user_policy cpufreq: remove redundant 'policy' field from user_policy cpufreq: remove redundant 'governor' field from user_policy cpufreq: update user_policy.* on success cpufreq: use memcpy() to copy policy cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier event cpufreq: mediatek: Add MT8173 cpufreq driver dt-bindings: mediatek: Add MT8173 CPU DVFS clock bindings PM / Domains: Fix typo in description of genpd_dev_pm_detach() PM / Domains: Remove unusable governor dummies PM / Domains: Make pm_genpd_init() available to modules PM / domains: Align column headers and data in pm_genpd_summary output powercap / RAPL: disable the 2nd power limit properly tools: cpupower: Fix error when running cpupower monitor PM / OPP: Drop unlikely before IS_ERR(_OR_NULL) PM / OPP: Fix static checker warning (broken 64bit big endian systems) ...
2015-08-31Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+4
Pull scheduler updates from Ingo Molnar: "The biggest change in this cycle is the rewrite of the main SMP load balancing metric: the CPU load/utilization. The main goal was to make the metric more precise and more representative - see the changelog of this commit for the gory details: 9d89c257dfb9 ("sched/fair: Rewrite runnable load and utilization average tracking") It is done in a way that significantly reduces complexity of the code: 5 files changed, 249 insertions(+), 494 deletions(-) and the performance testing results are encouraging. Nevertheless we need to keep an eye on potential regressions, since this potentially affects every SMP workload in existence. This work comes from Yuyang Du. Other changes: - SCHED_DL updates. (Andrea Parri) - Simplify architecture callbacks by removing finish_arch_switch(). (Peter Zijlstra et al) - cputime accounting: guarantee stime + utime == rtime. (Peter Zijlstra) - optimize idle CPU wakeups some more - inspired by Facebook server loads. (Mike Galbraith) - stop_machine fixes and updates. (Oleg Nesterov) - Introduce the 'trace_sched_waking' tracepoint. (Peter Zijlstra) - sched/numa tweaks. (Srikar Dronamraju) - misc fixes and small cleanups" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits) sched/deadline: Fix comment in enqueue_task_dl() sched/deadline: Fix comment in push_dl_tasks() sched: Change the sched_class::set_cpus_allowed() calling context sched: Make sched_class::set_cpus_allowed() unconditional sched: Fix a race between __kthread_bind() and sched_setaffinity() sched: Ensure a task has a non-normalized vruntime when returning back to CFS sched/numa: Fix NUMA_DIRECT topology identification tile: Reorganize _switch_to() sched, sparc32: Update scheduler comments in copy_thread() sched: Remove finish_arch_switch() sched, tile: Remove finish_arch_switch sched, sh: Fold finish_arch_switch() into switch_to() sched, score: Remove finish_arch_switch() sched, avr32: Remove finish_arch_switch() sched, MIPS: Get rid of finish_arch_switch() sched, arm: Remove finish_arch_switch() sched/fair: Clean up load average references sched/fair: Provide runnable_load_avg back to cfs_rq sched/fair: Remove task and group entity load when they are dead sched/fair: Init cfs_rq's sched_entity load average ...
2015-08-28cpuidle/coupled: Remove redundant 'dev' argument of cpuidle_state_is_coupled()Xunlei Pang1-2/+2
For cpuidle_state_is_coupled(), 'dev' is not used, so remove it. Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-21sched/idle: Move latency tracing stop/start calls deeper inside the idle loopLucas Stach1-0/+4
Make sure to stop tracing only once we are past a point where all latency tracing events have been processed (irqs are not enabled again). This has the slight advantage of capturing more latency related events in the idle path, but most importantly it makes sure that latency tracing doesn't get re-enabled inadvertently when new events are coming in. This makes the irqsoff latency tracer useful again, as we stop capturing CPU sleep time as IRQ latency. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kernel@pengutronix.de Cc: patchwork-lst@pengutronix.de Link: http://lkml.kernel.org/r/1437410090-3747-1-git-send-email-l.stach@pengutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-09suspend-to-idle: Prevent RCU from complaining about tick_freeze()Rafael J. Wysocki1-2/+7
Put tick_freeze() under RCU_NONIDLE() to prevent RCU from complaining about suspicious RCU usage in idle by trace_suspend_resume() called from there. While at it, fix a comment related to another usage of RCU_NONIDLE() in enter_freeze_proper(). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-06-19Merge branches 'pm-sleep' and 'pm-runtime'Rafael J. Wysocki1-0/+2
* pm-sleep: PM / sleep: trace_device_pm_callback coverage in dpm_prepare/complete PM / wakeup: add a dummy wakeup_source to record statistics PM / sleep: Make suspend-to-idle-specific code depend on CONFIG_SUSPEND PM / sleep: Return -EBUSY from suspend_enter() on wakeup detection PM / tick: Add tracepoints for suspend-to-idle diagnostics PM / sleep: Fix symbol name in a comment in kernel/power/main.c leds / PM: fix hibernation on arm when gpio-led used with CPU led trigger ARM: omap-device: use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS bus: omap_l3_noc: add missed callbacks for suspend-to-disk PM / sleep: Add macro to define common noirq system PM callbacks PM / sleep: Refine diagnostic messages in enter_state() PM / wakeup: validate wakeup source before activating it. * pm-runtime: PM / Runtime: Update last_busy in rpm_resume PM / runtime: add note about re-calling in during device probe()
2015-05-30cpuidle: Do not use CPUIDLE_DRIVER_STATE_START in cpuidle.cRafael J. Wysocki1-3/+3
The CPUIDLE_DRIVER_STATE_START symbol is defined as 1 only if CONFIG_ARCH_HAS_CPU_RELAX is set, otherwise it is defined as 0. However, if CONFIG_ARCH_HAS_CPU_RELAX is set, the first (index 0) entry in the cpuidle driver's table of states is overwritten with the default "poll" entry by the core. The "state" defined by the "poll" entry doesn't provide ->enter_dead and ->enter_freeze callbacks and its exit_latency is 0. For this reason, it is not necessary to use CPUIDLE_DRIVER_STATE_START in cpuidle_play_dead() (->enter_dead is NULL, so the "poll state" will be skipped by the loop). It also is arguably unuseful to return states with exit_latency equal to 0 from find_deepest_state(), so the function can be modified to start the loop from index 0 and the "poll state" will be skipped by it as a result of the check against latency_req. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
2015-05-19PM / sleep: Make suspend-to-idle-specific code depend on CONFIG_SUSPENDRafael J. Wysocki1-0/+2
Since idle_should_freeze() is defined to always return 'false' for CONFIG_SUSPEND unset, all of the code depending on it in cpuidle_idle_call() is not necessary in that case. Make that code depend on CONFIG_SUSPEND too to avoid building it when it is not going to be used. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-14cpuidle: Select a different state on tick_broadcast_enter() failuresRafael J. Wysocki1-5/+15
If tick_broadcast_enter() fails in cpuidle_enter_state(), try to find another idle state to enter instead of invoking default_idle_call() immediately and returning -EBUSY which should increase the chances of saving some energy in those cases. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Kevin Hilman <khilman@linaro.org>
2015-05-14sched / idle: Call default_idle_call() from cpuidle_enter_state()Rafael J. Wysocki1-1/+3
The check of the cpuidle_enter() return value against -EBUSY made in call_cpuidle() will not be necessary any more if cpuidle_enter_state() calls default_idle_call() directly when it is about to return -EBUSY, so make that happen and eliminate the check. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Kevin Hilman <khilman@linaro.org>
2015-05-14sched / idle: Call idle_set_state() from cpuidle_enter_state()Rafael J. Wysocki1-0/+6
Introduce a wrapper function around idle_set_state() called sched_idle_set_state() that will pass this_rq() to it as the first argument and make cpuidle_enter_state() call the new function before and after entering the target state. At the same time, remove direct invocations of idle_set_state() from call_cpuidle(). This will allow the invocation of default_idle_call() to be moved from call_cpuidle() to cpuidle_enter_state() safely and call_cpuidle() to be simplified a bit as a result. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Kevin Hilman <khilman@linaro.org>
2015-05-09cpuidle: Fix the kerneldoc comment for cpuidle_enter_state()Rafael J. Wysocki1-1/+1
The kerneldoc comment for cpuidle_enter_state() doesn't match the function's header any more, so fix it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-04cpuidle: Check the sign of index in cpuidle_reflect()Rafael J. Wysocki1-1/+1
Avoid calling the governor's ->reflect method if the state index passed to cpuidle_reflect() is negative. This allows the analogous check to be dropped from menu_reflect(), so do that too, and ensures that arbitrary error codes can be passed to cpuidle_reflect() as the index with no adverse consequences. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2015-04-29cpuidle: Run tick_broadcast_exit() with disabled interruptsRafael J. Wysocki1-0/+16
Commit 335f49196fd6 (sched/idle: Use explicit broadcast oneshot control function) replaced clockevents_notify() invocations in cpuidle_idle_call() with direct calls to tick_broadcast_enter() and tick_broadcast_exit(), but it overlooked the fact that interrupts were already enabled before calling the latter which led to functional breakage on systems using idle states with the CPUIDLE_FLAG_TIMER_STOP flag set. Fix that by moving the invocations of tick_broadcast_enter() and tick_broadcast_exit() down into cpuidle_enter_state() where interrupts are still disabled when tick_broadcast_exit() is called. Also ensure that interrupts will be disabled before running tick_broadcast_exit() even if they have been enabled by the idle state's ->enter callback. Trigger a WARN_ON_ONCE() in that case, as we generally don't want that to happen for states with CPUIDLE_FLAG_TIMER_STOP set. Fixes: 335f49196fd6 (sched/idle: Use explicit broadcast oneshot control function) Reported-and-tested-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reported-and-tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-04-03cpuidle: remove state_count field from struct cpuidle_deviceBartlomiej Zolnierkiewicz1-3/+0
Thomas Schlichter reports the following issue on his Samsung NC20: "The C-states C1 and C2 to the OS when connected to AC, and additionally provides the C3 C-state when disconnected from AC. However, the number of C-states shown in sysfs is fixed to the number of C-states present at boot. If I boot with AC connected, I always only see the C-states up to C2 even if I disconnect AC. The reason is commit 130a5f692425 (ACPI / cpuidle: remove dev->state_count setting). It removes the update of dev->state_count, but sysfs uses exactly this variable to show the C-states. The fix is to use drv->state_count in sysfs. As this is currently the last user of dev->state_count, this variable can be completely removed." Remove dev->state_count as per the above. Reported-by: Thomas Schlichter <thomas.schlichter@web.de> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: 3.14+ <stable@vger.kernel.org> # 3.14+ [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-03-05cpuidle / sleep: Use broadcast timer for states that stop local timerRafael J. Wysocki1-40/+22
Commit 381063133246 (PM / sleep: Re-implement suspend-to-idle handling) overlooked the fact that entering some sufficiently deep idle states by CPUs may cause their local timers to stop and in those cases it is necessary to switch over to a broadcast timer prior to entering the idle state. If the cpuidle driver in use does not provide the new ->enter_freeze callback for any of the idle states, that problem affects suspend-to-idle too, but it is not taken into account after the changes made by commit 381063133246. Fix that by changing the definition of cpuidle_enter_freeze() and re-arranging of the code in cpuidle_idle_call(), so the former does not call cpuidle_enter() any more and the fallback case is handled by cpuidle_idle_call() directly. Fixes: 381063133246 (PM / sleep: Re-implement suspend-to-idle handling) Reported-and-tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2015-02-28cpuidle / sleep: Do sanity checks in cpuidle_enter_freeze() tooRafael J. Wysocki1-7/+16
Modify cpuidle_enter_freeze() to do the sanity checks done by cpuidle_select() to avoid crashing the suspend-to-idle code path in case something is missing. Fixes: 381063133246 (PM / sleep: Re-implement suspend-to-idle handling) Original-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2015-02-28idle / sleep: Avoid excessive disabling and enabling interruptsRafael J. Wysocki1-3/+3
Disabling interrupts at the end of cpuidle_enter_freeze() is not useful, because its caller, cpuidle_idle_call(), re-enables them right away after invoking it. To avoid that unnecessary back and forth dance with interrupts, make cpuidle_enter_freeze() enable interrupts after calling enter_freeze_proper() and drop the local_irq_disable() at its end, so that all of the code paths in it end up with interrupts enabled. Then, cpuidle_idle_call() will not need to re-enable interrupts after calling cpuidle_enter_freeze() any more, because the latter will return with interrupts enabled, in analogy with cpuidle_enter(). Reported-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2015-02-15PM / sleep: Make it possible to quiesce timers during suspend-to-idleRafael J. Wysocki1-5/+44
The efficiency of suspend-to-idle depends on being able to keep CPUs in the deepest available idle states for as much time as possible. Ideally, they should only be brought out of idle by system wakeup interrupts. However, timer interrupts occurring periodically prevent that from happening and it is not practical to chase all of the "misbehaving" timers in a whack-a-mole fashion. A much more effective approach is to suspend the local ticks for all CPUs and the entire timekeeping along the lines of what is done during full suspend, which also helps to keep suspend-to-idle and full suspend reasonably similar. The idea is to suspend the local tick on each CPU executing cpuidle_enter_freeze() and to make the last of them suspend the entire timekeeping. That should prevent timer interrupts from triggering until an IO interrupt wakes up one of the CPUs. It needs to be done with interrupts disabled on all of the CPUs, though, because otherwise the suspended clocksource might be accessed by an interrupt handler which might lead to fatal consequences. Unfortunately, the existing ->enter callbacks provided by cpuidle drivers generally cannot be used for implementing that, because some of them re-enable interrupts temporarily and some idle entry methods cause interrupts to be re-enabled automatically on exit. Also some of these callbacks manipulate local clock event devices of the CPUs which really shouldn't be done after suspending their ticks. To overcome that difficulty, introduce a new cpuidle state callback, ->enter_freeze, that will be guaranteed (1) to keep interrupts disabled all the time (and return with interrupts disabled) and (2) not to touch the CPU timer devices. Modify cpuidle_enter_freeze() to look for the deepest available idle state with ->enter_freeze present and to make the CPU execute that callback with suspended tick (and the last of the online CPUs to execute it with suspended timekeeping). Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2015-02-13PM / sleep: Re-implement suspend-to-idle handlingRafael J. Wysocki1-23/+26
In preparation for adding support for quiescing timers in the final stage of suspend-to-idle transitions, rework the freeze_enter() function making the system wait on a wakeup event, the freeze_wake() function terminating the suspend-to-idle loop and the mechanism by which deep idle states are entered during suspend-to-idle. First of all, introduce a simple state machine for suspend-to-idle and make the code in question use it. Second, prevent freeze_enter() from losing wakeup events due to race conditions and ensure that the number of online CPUs won't change while it is being executed. In addition to that, make it force all of the CPUs re-enter the idle loop in case they are in idle states already (so they can enter deeper idle states if possible). Next, drop cpuidle_use_deepest_state() and replace use_deepest_state checks in cpuidle_select() and cpuidle_reflect() with a single suspend-to-idle state check in cpuidle_idle_call(). Finally, introduce cpuidle_enter_freeze() that will simply find the deepest idle state available to the given CPU and enter it using cpuidle_enter(). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2014-09-24sched: Let the scheduler see CPU idle statesDaniel Lezcano1-0/+6
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 Liu1-7/+2
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 Tripathy1-0/+2
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. Wysocki1-1/+44
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. Wysocki1-20/+6
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 git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-51/+56
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 git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds1-1/+2
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 Burton1-1/+2
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>