summaryrefslogtreecommitdiffstats
path: root/drivers/cpuidle/governors
Commit message (Collapse)AuthorAgeFilesLines
* Merge branch 'WIP.sched-core-for-linus' of ↵Linus Torvalds2017-03-031-0/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull sched.h split-up from Ingo Molnar: "The point of these changes is to significantly reduce the <linux/sched.h> header footprint, to speed up the kernel build and to have a cleaner header structure. After these changes the new <linux/sched.h>'s typical preprocessed size goes down from a previous ~0.68 MB (~22K lines) to ~0.45 MB (~15K lines), which is around 40% faster to build on typical configs. Not much changed from the last version (-v2) posted three weeks ago: I eliminated quirks, backmerged fixes plus I rebased it to an upstream SHA1 from yesterday that includes most changes queued up in -next plus all sched.h changes that were pending from Andrew. I've re-tested the series both on x86 and on cross-arch defconfigs, and did a bisectability test at a number of random points. I tried to test as many build configurations as possible, but some build breakage is probably still left - but it should be mostly limited to architectures that have no cross-compiler binaries available on kernel.org, and non-default configurations" * 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (146 commits) sched/headers: Clean up <linux/sched.h> sched/headers: Remove #ifdefs from <linux/sched.h> sched/headers: Remove the <linux/topology.h> include from <linux/sched.h> sched/headers, hrtimer: Remove the <linux/wait.h> include from <linux/hrtimer.h> sched/headers, x86/apic: Remove the <linux/pm.h> header inclusion from <asm/apic.h> sched/headers, timers: Remove the <linux/sysctl.h> include from <linux/timer.h> sched/headers: Remove <linux/magic.h> from <linux/sched/task_stack.h> sched/headers: Remove <linux/sched.h> from <linux/sched/init.h> sched/core: Remove unused prefetch_stack() sched/headers: Remove <linux/rculist.h> from <linux/sched.h> sched/headers: Remove the 'init_pid_ns' prototype from <linux/sched.h> sched/headers: Remove <linux/signal.h> from <linux/sched.h> sched/headers: Remove <linux/rwsem.h> from <linux/sched.h> sched/headers: Remove the runqueue_is_locked() prototype sched/headers: Remove <linux/sched.h> from <linux/sched/hotplug.h> sched/headers: Remove <linux/sched.h> from <linux/sched/debug.h> sched/headers: Remove <linux/sched.h> from <linux/sched/nohz.h> sched/headers: Remove <linux/sched.h> from <linux/sched/stat.h> sched/headers: Remove the <linux/gfp.h> include from <linux/sched.h> sched/headers: Remove <linux/rtmutex.h> from <linux/sched.h> ...
| * sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | <linux/sched/stat.h> We are going to split <linux/sched/stat.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/stat.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>
| * sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | <linux/sched/loadavg.h> We are going to split <linux/sched/loadavg.h> out of <linux/sched.h>, which will have to be picked up from a couple of .c files. Create a trivial placeholder <linux/sched/topology.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>
* | cpuidle: menu: Avoid taking spinlock for accessing QoS valuesRafael J. Wysocki2017-02-271-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | After commit 9908859acaa9 (cpuidle/menu: add per CPU PM QoS resume latency consideration) the cpuidle menu governor calls dev_pm_qos_read_value() on CPU devices to read the current resume latency QoS constraint values for them. That function takes a spinlock to prevent the device's power.qos pointer from becoming NULL during the access which is a problem for the RT patchset where spinlocks are converted into mutexes and the idle loop stops working. However, it is not even necessary for the menu governor to take that spinlock, because the power.qos pointer accessed under it cannot be modified during the access anyway. For this reason, introduce a "raw" routine for accessing device QoS resume latency constraints without locking and use it in the menu governor. Fixes: 9908859acaa9 (cpuidle/menu: add per CPU PM QoS resume latency consideration) Acked-by: Alex Shi <alex.shi@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle/menu: add per CPU PM QoS resume latency considerationAlex Shi2017-01-301-0/+7
| | | | | | | | | | | | | | | | | There may be special requirements on CPU response time, like if a interrupt is pinned to a CPU, that CPU should not go into excessively deep idle states. For this reason, add a mechanism for adding PM QoS resume latency constraints for individual CPUs and modify the menu governor to take them into account. To that end, extend the device PM QoS pm_qos_resume_latency attribute to CPUs, which is possible, because the exit latency for CPUs is effectively equivalent to the resume latency for devices. Signed-off-by: Alex Shi <alex.shi@linaro.org> Acked-by: Rik van Riel <riel@redhat.com> [ rjw : Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle/menu: stop seeking deeper idle if current state is deep enoughAlex Shi2017-01-301-2/+2
| | | | | | | | | | | | | | | Obsolete commit 71abbbf856a0 (cpuidle: extend cpuidle and menu governor to handle dynamic states) wanted to introduce dynamic C-states, but that idea was dropped long ago. The nonsense deeper C-state checking remained, though. Since both target_residency and exit_latency are longer for deeper idle state, there's no need to waste CPU time on useless checks. Signed-off-by: Alex Shi <alex.shi@linaro.org> Acked-by: Rik van Riel <riel@redhat.com> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds2016-12-241-1/+1
| | | | | | | | | | | | | This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cpuidle: governors: Remove remaining old module codeDaniel Lezcano2016-10-212-4/+0
| | | | | | | | | | | | The governor's code use try_module_get() and put_module() to refcount the governor's module. But the governors are not compiled as module. The refcount does not prevent to switch the governor or unload a module as they aren't compiled as modules. The code is pointless, so remove it. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: menu: Fall back to polling if next timer event is nearRafael J. Wysocki2016-03-211-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | Commit a9ceb78bc75c (cpuidle,menu: use interactivity_req to disable polling) changed the behavior of the fallback state selection part of menu_select() so it looks at interactivity_req instead of data->next_timer_us when it makes its decision. That effectively caused polling to be used more often as fallback idle which led to significant increases of energy consumption in some cases. Commit e132b9b3bc7f (cpuidle: menu: use high confidence factors only when considering polling) changed that logic again to be more predictable, but that didn't help with the increased energy consumption problem. For this reason, go back to making decisions on which state to fall back to based on data->next_timer_us which is the time we know for sure something will happen rather than a prediction (which may be inaccurate and turns out to be so often enough to be problematic). However, take the target residency of the first proper idle state (C1) into account, so that state is not used as the fallback one if its target residency is greater than data->next_timer_us. Fixes: a9ceb78bc75c (cpuidle,menu: use interactivity_req to disable polling) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reported-and-tested-by: Doug Smythies <dsmythies@telus.net>
* cpuidle: menu: use high confidence factors only when considering pollingRik van Riel2016-03-171-18/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | The menu governor uses five different factors to pick the idle state: - the user configured latency_req - the time until the next timer (next_timer_us) - the typical sleep interval, as measured recently - an estimate of sleep time by dividing next_timer_us by an observed factor - a load corrected version of the above, divided again by load Only the first three items are known with enough confidence that we can use them to consider polling, instead of an actual CPU idle state, because the cost of being wrong about polling can be excessive power use. The latter two are used in the menu governor's main selection loop, and can result in choosing a shallower idle state when the system is expected to be busy again soon. This pushes a busy system in the "performance" direction of the performance<>power tradeoff, when choosing between idle states, but stays more strictly on the "power" state when deciding between polling and C1. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: menu: help gcc generate slightly better codeRasmus Villemoes2016-02-171-8/+8
| | | | | | | | | | | We know that the avg variable actually ends up holding a 32 bit quantity, since it's an average of such numbers. It is only a u64 because it is temporarily used to hold the sum. Making it an actual u32 allows gcc to generate slightly better code, e.g. when computing the square, it can do a 32x32->64 multiply. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: menu: avoid expensive square root computationRasmus Villemoes2016-02-171-18/+17
| | | | | | | | | | | | | | | | | | Computing the integer square root is a rather expensive operation, at least compared to doing a 64x64 -> 64 multiply (avg*avg) and, on 64 bit platforms, doing an extra comparison to a constant (variance <= U64_MAX/36). On 64 bit platforms, this does mean that we add a restriction on the range of the variance where we end up using the estimate (since previously the stddev <= ULONG_MAX was a tautology), but on the other hand, we extend the range quite substantially on 32 bit platforms - in both cases, we now allow standard deviations up to 715 seconds, which is for example guaranteed if all observations are less than 1430 seconds. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: menu: Avoid pointless checks in menu_select()Rafael J. Wysocki2016-01-191-1/+1
| | | | | | | | | | | | | | | If menu_select() cannot find a suitable state to return, it will return the state index stored in data->last_state_idx. This means that it is pointless to look at the states whose indices are less than or equal to data->last_state_idx in the main loop, so don't do that. Given that those checks are done on every idle state selection, this change can save quite a bit of completely unnecessary overhead. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Tested-by: Sudeep Holla <sudeep.holla@arm.com>
* cpuidle: Default to ladder governor on ticking systemsJean Delvare2016-01-151-0/+9
| | | | | | | | | | | | | The menu governor is currently the default on all systems. However the documentation claims that the ladder governor is preferred on ticking systems. So bump the rating of the ladder governor when NO_HZ is disabled, or when booting with nohz=off. This fixes the first half of kernel BZ #65531. Link: https://bugzilla.kernel.org/show_bug.cgi?id=65531 Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: menu: Fix menu_select() for CPUIDLE_DRIVER_STATE_START == 0Rafael J. Wysocki2016-01-141-9/+12
| | | | | | | | | | | | | | | | | | | | Commit a9ceb78bc75c (cpuidle,menu: use interactivity_req to disable polling) exposed a bug in menu_select() causing it to return -1 on systems with CPUIDLE_DRIVER_STATE_START equal to zero, although it should have returned 0. As a result, idle states are not entered by CPUs on those systems. Namely, on the systems in question data->last_state_idx is initially equal to -1 and the above commit modified the condition that would have caused it to be changed to 0 to be less likely to trigger which exposed the problem. However, setting data->last_state_idx initially to -1 doesn't make sense at all and on the affected systems it should always be set to CPUIDLE_DRIVER_STATE_START (ie. 0) unconditionally, so make that happen. Fixes: a9ceb78bc75c (cpuidle,menu: use interactivity_req to disable polling) Reported-and-tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle,menu: smooth out measured_us calculationRik van Riel2015-11-171-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The cpuidle state tables contain the maximum exit latency for each cpuidle state. On x86, that is the exit latency for when the entire package goes into that same idle state. However, a lot of the time we only go into the core idle state, not the package idle state. This means we see a much smaller exit latency. We have no way to detect whether we went into the core or package idle state while idle, and that is ok. However, the current menu_update logic does have the potential to trip up the repeating pattern detection in get_typical_interval. If the system is experiencing an exit latency near the idle state's exit latency, some of the samples will have exit_us subtracted, while others will not. This turns a repeating pattern into mush, potentially breaking get_typical_interval. Furthermore, for smaller sleep intervals, we know the chance that all the cores in the package went to the same idle state are fairly small. Dividing the measured_us by two, instead of subtracting the full exit latency when hitting a small measured_us, will reduce the error. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle,menu: use interactivity_req to disable pollingRik van Riel2015-11-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | The menu governor carefully figures out how much time we typically sleep for an estimated sleep interval, or whether there is a repeating pattern going on, and corrects that estimate for the CPU load. Then it proceeds to ignore that information when determining whether or not to consider polling. This is not a big deal on most x86 CPUs, which have very low C1 latencies, and the patch should not have any effect on those CPUs. However, certain CPUs (eg. Atom) have much higher C1 latencies, and it would be good to not waste performance and power on those CPUs if we are expecting a very low wakeup latency. Disable polling based on the estimated interactivity requirement, not on the time to the next timer interrupt. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle,x86: increase forced cut-off for polling to 20usRik van Riel2015-11-171-1/+1
| | | | | | | | | | | | | | | | | | | | The cpuidle menu governor has a forced cut-off for polling at 5us, in order to deal with firmware that gives the OS bad information on cpuidle states, leading to the system spending way too much time in polling. However, at least one x86 CPU family (Atom) has chips that have a 20us break-even point for C1. Forcing the polling cut-off to less than that wastes performance and power. Increase the polling cut-off to 20us. Systems with a lower C1 latency will be found in the states table by the menu governor, which will pick those states as appropriate. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: Check the sign of index in cpuidle_reflect()Rafael J. Wysocki2015-05-041-2/+2
| | | | | | | | | | | | | | 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>
* cpuidle: menu: use DIV_ROUND_CLOSEST_ULL()Javi Merino2015-04-171-7/+1
| | | | | | | | | | | | Now that the kernel provides DIV_ROUND_CLOSEST_ULL(), drop the internal implementation and use the kernel one. Signed-off-by: Javi Merino <javi.merino@arm.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cpuidle: ladder: Better idle duration measurement without using ↵Len Brown2014-12-171-6/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CPUIDLE_FLAG_TIME_INVALID When the ladder governor sees the CPUIDLE_FLAG_TIME_INVALID flag, it unconditionally causes a state promotion by setting last_residency to a number higher than the state's promotion_time: last_residency = last_state->threshold.promotion_time + 1 It does this for fear that cpuidle_get_last_residency() will be in-accurate, because cpuidle_enter_state() invoked a state with CPUIDLE_FLAG_TIME_INVALID. But the only state with CPUIDLE_FLAG_TIME_INVALID is acpi_safe_halt(), which may return well after its actual idle duration because it enables interrupts, so cpuidle_enter_state() also measures interrupt service time. So what? In ladder, a huge invalid last_residency has exactly the same effect as the current code -- it unconditionally causes a state promotion. In the case where the idle residency plus measured interrupt handling time is less than the state's demotion_time -- we should use that timestamp to give ladder a chance to demote, rather than unconditionally promoting. This can be done by simply ignoring the CPUIDLE_FLAG_TIME_INVALID, and using the "invalid" time, as it is either equal to what we are doing today, or better. Signed-off-by: Len Brown <len.brown@intel.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: menu: Better idle duration measurement without using ↵Len Brown2014-12-171-15/+10
| | | | | | | | | | | | | | | | | | | | | | | | | CPUIDLE_FLAG_TIME_INVALID When menu sees CPUIDLE_FLAG_TIME_INVALID, it ignores its timestamps, and assumes that idle lasted as long as the time till next predicted timer expiration. But if an interrupt was seen and serviced before that duration, it would actually be more accurate to use the measured time rather than rounding up to the next predicted timer expiration. And if an interrupt is seen and serviced such that the mesured time exceeds the time till next predicted timer expiration, then truncating to that expiration is the right thing to do -- since we can never stay idle past that timer expiration. So the code can do a better job without checking for CPUIDLE_FLAG_TIME_INVALID. Signed-off-by: Len Brown <len.brown@intel.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: Invert CPUIDLE_FLAG_TIME_VALID logicDaniel Lezcano2014-11-122-2/+2
| | | | | | | | | | | | | | | The only place where the time is invalid is when the ACPI_CSTATE_FFH entry method is not set. Otherwise for all the drivers, the time can be correctly measured. Instead of duplicating the CPUIDLE_FLAG_TIME_VALID flag in all the drivers for all the states, just invert the logic by replacing it by the flag CPUIDLE_FLAG_TIME_INVALID, hence we can set this flag only for the acpi idle driver, remove the former flag from all the drivers and invert the logic with this flag in the different governor. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* drivers/cpuidle: Replace __get_cpu_var uses for address calculationChristoph Lameter2014-08-262-5/+5
| | | | | | | | | | | | All of these are for address calculation. Replace with this_cpu_ptr(). Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: linux-pm@vger.kernel.org Acked-by: Rafael J. Wysocki <rjw@sisk.pl> [cpufreq changes] Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* Merge tag 'pm+acpi-3.17-rc1-2' of ↵Linus Torvalds2014-08-141-20/+23
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more ACPI and power management updates from Rafael Wysocki: "These are a couple of regression fixes, cpuidle menu governor optimizations, fixes for ACPI proccessor and battery drivers, hibernation fix to avoid problems related to the e820 memory map, fixes for a few cpufreq drivers and a new version of the suspend profiling tool analyze_suspend.py. Specifics: - Fix for an ACPI-based device hotplug regression introduced in 3.14 that causes a kernel panic to trigger when memory hot-remove is attempted with CONFIG_ACPI_HOTPLUG_MEMORY unset from Tang Chen - Fix for a cpufreq regression introduced in 3.16 that triggers a "sleeping function called from invalid context" bug in dev_pm_opp_init_cpufreq_table() from Stephen Boyd - ACPI battery driver fix for a warning message added in 3.16 that prints silly stuff sometimes from Mariusz Ceier - Hibernation fix for safer handling of mismatches in the 820 memory map between the configurations during image creation and during the subsequent restore from Chun-Yi Lee - ACPI processor driver fix to handle CPU hotplug notifications correctly during system suspend/resume from Lan Tianyu - Series of four cpuidle menu governor cleanups that also should speed it up a bit from Mel Gorman - Fixes for the speedstep-smi, integrator, cpu0 and arm_big_little cpufreq drivers from Hans Wennborg, Himangi Saraogi, Markus Pargmann and Uwe Kleine-König - Version 3.0 of the analyze_suspend.py suspend profiling tool from Todd E Brandt" * tag 'pm+acpi-3.17-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI / battery: Fix warning message in acpi_battery_get_state() PM / tools: analyze_suspend.py: update to v3.0 cpufreq: arm_big_little: fix module license spec cpufreq: speedstep-smi: fix decimal printf specifiers ACPI / hotplug: Check scan handlers in acpi_scan_hot_remove() cpufreq: OPP: Avoid sleeping while atomic cpufreq: cpu0: Do not print error message when deferring cpufreq: integrator: Use set_cpus_allowed_ptr PM / hibernate: avoid unsafe pages in e820 reserved regions ACPI / processor: Make acpi_cpu_soft_notify() process CPU FROZEN events cpuidle: menu: Lookup CPU runqueues less cpuidle: menu: Call nr_iowait_cpu less times cpuidle: menu: Use ktime_to_us instead of reinventing the wheel cpuidle: menu: Use shifts when calculating averages where possible
| * cpuidle: menu: Lookup CPU runqueues lessMel Gorman2014-08-061-10/+7
| | | | | | | | | | | | | | | | The menu governer makes separate lookups of the CPU runqueue to get load and number of IO waiters but it can be done with a single lookup. Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpuidle: menu: Call nr_iowait_cpu less timesMel Gorman2014-08-061-7/+8
| | | | | | | | | | | | | | | | menu_select() via inline functions calls nr_iowait_cpu() twice as much as necessary. Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpuidle: menu: Use ktime_to_us instead of reinventing the wheelMel Gorman2014-08-061-4/+1
| | | | | | | | | | | | | | | | | | The ktime_to_us implementation is slightly better than the one implemented in menu.c. Use it Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpuidle: menu: Use shifts when calculating averages where possibleMel Gorman2014-08-061-3/+11
| | | | | | | | | | | | | | | | We use do_div even though the divisor will usually be a power-of-two unless there are unusual outliers. Use shifts where possible Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | Merge branch 'for-linus' of ↵Linus Torvalds2014-08-061-1/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree changes from Jiri Kosina: "Summer edition of trivial tree updates" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (23 commits) doc: fix two typos in watchdog-api.txt irq-gic: remove file name from heading comment MAINTAINERS: Add miscdevice.h to file list for char/misc drivers. scsi: mvsas: mv_sas.c: Fix for possible null pointer dereference doc: replace "practise" with "practice" in Documentation befs: remove check for CONFIG_BEFS_RW scsi: doc: fix 'SCSI_NCR_SETUP_MASTER_PARITY' drivers/usb/phy/phy.c: remove a leading space mfd: fix comment cpuidle: fix comment doc: hpfall.c: fix missing null-terminate after strncpy call usb: doc: hotplug.txt code typos kbuild: fix comment in Makefile.modinst SH: add proper prompt to SH_MAGIC_PANEL_R2_VERSION ARM: msm: Remove MSM_SCM crypto: Remove MPILIB_EXTRA doc: CN: remove dead link, kerneltrap.org no longer works media: update reference, kerneltrap.org no longer works hexagon: update reference, kerneltrap.org no longer works doc: LSM: update reference, kerneltrap.org no longer works ...
| * cpuidle: fix commentAntonio Ospite2014-06-191-1/+1
| | | | | | | | | | | | | | Signed-off-by: Antonio Ospite <ao2@ao2.it> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: "tuukka.tikkanen@linaro.org" <tuukka.tikkanen@linaro.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | cpuidle: ladder governor - use macro instead of hardcoded valueMohammad Merajul Islam Molla2014-07-291-2/+2
| | | | | | | | | | | | | | | | | | use CPUIDLE_DRIVER_STATE_START, instead of hardcoded value 0. As, CPUIDLE_DRIVER_STATE_START can be 1/0 based on CONFIG_ARCH_HAS_CPU_RELAX is defined or not. Signed-off-by: Mohammad Merajul Islam Molla <meraj.enigma@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | cpuidle: menu governor - remove unused macro STDDEV_THRESHMohammad Merajul Islam Molla2014-07-281-1/+0
| | | | | | | | | | | | | | | | STDDEV_THRESH was once defined and used in menu governor. But now its no longer used anywhere. So removing the define. Signed-off-by: Mohammad Merajul Islam Molla <meraj.enigma@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | cpuidle / menu: move repeated correction factor check to initChander Kashyap2014-05-011-7/+8
| | | | | | | | | | | | | | | | | | | | In menu_select function we check for correction factor every time. If it is zero we are initializing to unity. Hence move it to init function and initialise by unity, hence avoid repeated comparisons. Signed-off-by: Chander Kashyap <chander.kashyap@linaro.org> Reviewed-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | cpuidle / menu: Return (-1) if there are no suitable statesRafael J. Wysocki2014-05-011-1/+1
|/ | | | | | | | | | | | If there is a PM QoS latency limit and all of the sufficiently shallow C-states are disabled, the cpuidle menu governor returns 0 which on some systems is CPUIDLE_DRIVER_STATE_START and shouldn't be returned if that C-state has been disabled. Fix the issue by modifying the menu governor to return (-1) in such situations. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: Move perf multiplier calculation out of the selection looptuukka.tikkanen@linaro.org2014-03-061-5/+10
| | | | | | | | | | | | | | | | | | | | | The menu governor performance multiplier defines a minimum predicted idle duration to latency ratio. Instead of checking this separately in every iteration of the state selection loop, adjust the overall latency restriction for the whole loop if this restriction is tighter than what is set by the QoS subsystem. The original test s->exit_latency * multiplier > data->predicted_us becomes s->exit_latency > data->predicted_us / multiplier by dividing both sides of the comparison by "multiplier". While division is likely to be several times slower than multiplication, the minor performance hit allows making a generic sleep state selection function based on (sleep duration, maximum latency) tuple. Signed-off-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: Do not substract exit latency from assumed sleep lengthtuukka.tikkanen@linaro.org2014-03-061-18/+26
| | | | | | | | | | | | | | | | | | | The menu governor statistics update function tries to determine the amount of time between entry to low power state and the occurrence of the wakeup event. However, the time measured by the framework includes exit latency on top of the desired value. This exit latency is substracted from the measured value to obtain the desired value. When measured value is not available, the menu governor assumes the wakeup was caused by the timer and the time is equal to remaining timer length. No exit latency should be substracted from this value. This patch prevents the erroneous substraction and clarifies the associated comment. It also removes one intermediate variable that serves no purpose. Signed-off-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: Ensure menu coefficients stay within domaintuukka.tikkanen@linaro.org2014-03-061-0/+3
| | | | | | | | | | | | | | | | | | | | | | The menu governor uses coefficients as one method of actual idle period length estimation. The coefficients are, as detailed below, multipliers giving expected idle period length from time until next timer expiry. The multipliers are supposed to have domain of (0..1]. The coefficients are fractions where only the numerators are stored and denominators are a shared constant RESOLUTION*DECAY. Since the value of the coefficient should always be greater than 0 and less than or equal to 1, the numerator must have a value greater than 0 and less than or equal to RESOLUTION*DECAY. If the coefficients are updated with measured idle durations exceeding timer length, the multiplier may reach values exceeding unity (i.e. the stored numerator exceeds RESOLUTION*DECAY). This patch ensures that the multipliers are updated with durations capped to timer length. Signed-off-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: Use actual state latency in menu governortuukka.tikkanen@linaro.org2014-03-061-5/+2
| | | | | | | | | | | | | Currently menu governor records the exit latency of the state it has chosen for the idle period. The stored latency value is then later used to calculate the actual length of the idle period. This value may however be incorrect, as the entered state may not be the one chosen by the governor. The entered state information is available, so we can use that to obtain the real exit latency. Signed-off-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: rename expected_us to next_timer_us in menu governortuukka.tikkanen@linaro.org2014-03-061-9/+9
| | | | | | | | | | | | | | | | The field expected_us is used to store the time remaining until next timer expiry. The name is inaccurate, as we really do not expect all wakeups to be caused by timers. In addition, another field with a very similar name (predicted_us) is used to store the predicted time remaining until any wakeup source being active. This patch renames expected_us to next_timer_us in order to better reflect the contained information. Signed-off-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Len Brown <len.brown@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: Change struct menu_device field typesTuukka Tikkanen2013-08-231-11/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Field predicted_us value can never exceed expected_us value, but it has a potentially larger type. As there is no need for additional 32 bits of zeroes on 32 bit plaforms, change the type of predicted_us to match the type of expected_us. Field correction_factor is used to store a value that cannot exceed the product of RESOLUTION and DECAY (default 1024*8 = 8192). The constants cannot in practice be incremented to such values, that they'd overflow unsigned int even on 32 bit systems, so the type is changed to avoid unnecessary 64 bit arithmetic on 32 bit systems. One multiplication of (now) 32 bit values needs an added cast to avoid truncation of the result and has been added. In order to avoid another multiplication from 32 bit domain to 64 bit domain, the new correction_factor calculation has been changed from new = old * (DECAY-1) / DECAY to new = old - old / DECAY, which with infinite precision would yeild exactly the same result, but now changes the direction of rounding. The impact is not significant as the maximum accumulated difference cannot exceed the value of DECAY, which is relatively small compared to product of RESOLUTION and DECAY (8 / 8192). Signed-off-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: Add a comment warning about possible overflowTuukka Tikkanen2013-08-231-0/+9
| | | | | | | | | | | | | The menu governor has a number of tunable constants that may be changed in the source. If certain combination of values are chosen, an overflow is possible when the correction_factor is being recalculated. This patch adds a warning regarding this possibility and describes the change needed for fixing the issue. The change should not be permanently enabled, as it will hurt performance when it is not needed. Signed-off-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: Fix variable domains in get_typical_interval()Tuukka Tikkanen2013-08-231-6/+9
| | | | | | | | | | | | | | | | | | | The menu governor uses a static function get_typical_interval() to try to detect a repeating pattern of wakeups. The previous interval durations are stored as an array of unsigned ints, but the arithmetic in the function is performed exclusively as 64 bit values, even when the value stored in a variable is known not to exceed unsigned int, which may be smaller and more efficient on some platforms. This patch changes the types of varibles used to store some intermediates, the maximum and and the cutoff threshold to unsigned ints. Average and standard deviation are still treated as 64 bit values, even when the values are known to be within the domain of unsigned int, to avoid casts to ensure correct integer promotion for arithmetic operations. Signed-off-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: Fix menu_device->intervals typeTuukka Tikkanen2013-08-231-1/+1
| | | | | | | | | Struct menu_device member intervals is declared as u32, but the value stored is (unsigned) int. The type is changed to match the value being stored. Signed-off-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: CodingStyle: Break up multiple assignments on single lineTuukka Tikkanen2013-08-231-3/+6
| | | | | | | | | | | | | The function get_typical_interval() initializes a number of variables that are immediately after declarations assigned constant values. In addition, there are multiple assignments on a single line, which is explicitly forbidden by Documentation/CodingStyle. This patch removes redundant initial values for the variables and breaks up the multiple assignment line. Signed-off-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: Check called function parameter in get_typical_interval()Tuukka Tikkanen2013-08-231-5/+13
| | | | | | | | | | | | | | get_typical_interval() uses int_sqrt() in calculation of standard deviation. The formal parameter of int_sqrt() is unsigned long, which may on some platforms be smaller than the 64 bit unsigned integer used as the actual parameter. The overflow can occur frequently when actual idle period lengths are in hundreds of milliseconds. This patch adds a check for such overflow and rejects the candidate average when an overflow would occur. Signed-off-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: Rearrange code and comments in get_typical_interval()Tuukka Tikkanen2013-08-231-13/+15
| | | | | | | | | | | This patch rearranges a if-return-elsif-goto-fi-return sequence into if-return-fi-if-return-fi-goto sequence. The functionality remains the same. Also, a lengthy comment that did not describe the functionality in the order it occurs is split into half and top half is moved closer to actual implementation it describes. Signed-off-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpuidle: Ignore interval prediction result when timer is shorterTuukka Tikkanen2013-08-231-1/+4
| | | | | | | | | This patch prevents cpuidle menu governor from using repeating interval prediction result if the idle period predicted is longer than the one allowed by shortest running timer. Signed-off-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* Merge back earlier 'pm-cpuidle' material.Rafael J. Wysocki2013-08-142-22/+2
|\
| * cpuidle: Make it clear that governors cannot be modulesDaniel Lezcano2013-07-152-22/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cpufreq governors are defined as modules in the code, but the Kconfig options do not allow them to be built as modules. This is not really a problem, but the cpuidle init ordering is: the cpuidle init functions (framework and driver) and then the governors. That leads to some weirdness in the cpuidle framework. Namely, cpuidle_register_device() calls cpuidle_enable_device() which fails at the first attempt, because governors have not been registered yet. When a governor is registered, the framework calls cpuidle_enable_device() again which runs __cpuidle_register_device() only then. Of course, for that to work, the cpuidle_enable_device() return value has to be ignored by cpuidle_register_device(). Instead of having this cyclic call graph and relying on a positive side effects of the hackish back and forth cpuidle_enable_device() calls it is better to fix the cpuidle init ordering. To that end, replace the module init code with postcore_initcall() so we have: * cpuidle framework : core_initcall * cpuidle governors : postcore_initcall * cpuidle drivers : device_initcall and remove the corresponding module exit code as it is dead anyway (governors can't be built as modules). [rjw: Changelog] Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
OpenPOWER on IntegriCloud