Add weak function to return the hardware maximum frequency of a CPU,
with the default implementation returning cpuinfo.max_freq, which is
the best information we can generically get from the cpufreq framework.
The default can be overwritten by a strong function in platforms
that want to provide an alternative implementation, with more accurate
information, obtained either from hardware or firmware.
Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The cpufreq_global_kobject is only used internally by cpufreq.c
after commit 2361be2366 ("cpufreq: Don't create empty
/sys/devices/system/cpu/cpufreq directory").
Make it static.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
[ rjw: Add empty line after cpufreq_global_kobject definition ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In the process of modifying a cpufreq policy, the cpufreq core makes
a copy of it including all of the internals which is stored on the
CPU stack. Because struct cpufreq_policy is relatively large, this
may cause the size of the stack frame to exceed the 2 KB limit and
so the GCC complains when -Wframe-larger-than= is used.
In fact, it is not necessary to copy the entire policy structure
in order to modify it, however.
First, because cpufreq_set_policy() obtains the min and max policy
limits from frequency QoS now, it is not necessary to pass the limits
to it from the callers. The only things that need to be passed to it
from there are the new governor pointer or (if there is a built-in
governor in the driver) the "policy" value representing the governor
choice. They both can be passed as individual arguments, though, so
make cpufreq_set_policy() take them this way and rework its callers
accordingly. This avoids making copies of cpufreq policies in the
callers of cpufreq_set_policy().
Second, cpufreq_set_policy() still needs to pass the new policy
data to the ->verify() callback of the cpufreq driver whose task
is to sanitize the min and max policy limits. It still does not
need to make a full copy of struct cpufreq_policy for this purpose,
but it needs to pass a few items from it to the driver in case they
are needed (different drivers have different needs in that respect
and all of them have to be covered). For this reason, introduce
struct cpufreq_policy_data to hold copies of the members of
struct cpufreq_policy used by the existing ->verify() driver
callbacks and pass a pointer to a temporary structure of that
type to ->verify() (instead of passing a pointer to full struct
cpufreq_policy to it).
While at it, notice that intel_pstate and longrun don't really need
to verify the "policy" value in struct cpufreq_policy, so drop those
check from them to avoid copying "policy" into struct
cpufreq_policy_data (which allows it to be slightly smaller).
Also while at it fix up white space in a couple of places and make
cpufreq_set_policy() static (as it can be so).
Fixes: 3000ce3c52 ("cpufreq: Use per-policy frequency QoS")
Link: https://lore.kernel.org/linux-pm/CAMuHMdX6-jb1W8uC2_237m8ctCpsnGp=JCxqt8pCWVqNXHmkVg@mail.gmail.com
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
The scheduler code calling cpufreq_update_util() may run during CPU
offline on the target CPU after the IRQ work lists have been flushed
for it, so the target CPU should be prevented from running code that
may queue up an IRQ work item on it at that point.
Unfortunately, that may not be the case if dvfs_possible_from_any_cpu
is set for at least one cpufreq policy in the system, because that
allows the CPU going offline to run the utilization update callback
of the cpufreq governor on behalf of another (online) CPU in some
cases.
If that happens, the cpufreq governor callback may queue up an IRQ
work on the CPU running it, which is going offline, and the IRQ work
may not be flushed after that point. Moreover, that IRQ work cannot
be flushed until the "offlining" CPU goes back online, so if any
other CPU calls irq_work_sync() to wait for the completion of that
IRQ work, it will have to wait until the "offlining" CPU is back
online and that may not happen forever. In particular, a system-wide
deadlock may occur during CPU online as a result of that.
The failing scenario is as follows. CPU0 is the boot CPU, so it
creates a cpufreq policy and becomes the "leader" of it
(policy->cpu). It cannot go offline, because it is the boot CPU.
Next, other CPUs join the cpufreq policy as they go online and they
leave it when they go offline. The last CPU to go offline, say CPU3,
may queue up an IRQ work while running the governor callback on
behalf of CPU0 after leaving the cpufreq policy because of the
dvfs_possible_from_any_cpu effect described above. Then, CPU0 is
the only online CPU in the system and the stale IRQ work is still
queued on CPU3. When, say, CPU1 goes back online, it will run
irq_work_sync() to wait for that IRQ work to complete and so it
will wait for CPU3 to go back online (which may never happen even
in principle), but (worse yet) CPU0 is waiting for CPU1 at that
point too and a system-wide deadlock occurs.
To address this problem notice that CPUs which cannot run cpufreq
utilization update code for themselves (for example, because they
have left the cpufreq policies that they belonged to), should also
be prevented from running that code on behalf of the other CPUs that
belong to a cpufreq policy with dvfs_possible_from_any_cpu set and so
in that case the cpufreq_update_util_data pointer of the CPU running
the code must not be NULL as well as for the CPU which is the target
of the cpufreq utilization update in progress.
Accordingly, change cpufreq_this_cpu_can_update() into a regular
function in kernel/sched/cpufreq.c (instead of a static inline in a
header file) and make it check the cpufreq_update_util_data pointer
of the local CPU if dvfs_possible_from_any_cpu is set for the target
cpufreq policy.
Also update the schedutil governor to do the
cpufreq_this_cpu_can_update() check in the non-fast-switch
case too to avoid the stale IRQ work issues.
Fixes: 99d14d0e16 ("cpufreq: Process remote callbacks from any CPU if the platform permits")
Link: https://lore.kernel.org/linux-pm/20191121093557.bycvdo4xyinbc5cb@vireshk-i7/
Reported-by: Anson Huang <anson.huang@nxp.com>
Tested-by: Anson Huang <anson.huang@nxp.com>
Cc: 4.14+ <stable@vger.kernel.org> # 4.14+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Peng Fan <peng.fan@nxp.com> (i.MX8QXP-MEK)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Replace the CPU device PM QoS used for the management of min and max
frequency constraints in cpufreq (and its users) with per-policy
frequency QoS to avoid problems with cpufreq policies covering
more then one CPU.
Namely, a cpufreq driver is registered with the subsys interface
which calls cpufreq_add_dev() for each CPU, starting from CPU0, so
currently the PM QoS notifiers are added to the first CPU in the
policy (i.e. CPU0 in the majority of cases).
In turn, when the cpufreq driver is unregistered, the subsys interface
doing that calls cpufreq_remove_dev() for each CPU, starting from CPU0,
and the PM QoS notifiers are only removed when cpufreq_remove_dev() is
called for the last CPU in the policy, say CPUx, which as a rule is
not CPU0 if the policy covers more than one CPU. Then, the PM QoS
notifiers cannot be removed, because CPUx does not have them, and
they are still there in the device PM QoS notifiers list of CPU0,
which prevents new PM QoS notifiers from being registered for CPU0
on the next attempt to register the cpufreq driver.
The same issue occurs when the first CPU in the policy goes offline
before unregistering the driver.
After this change it does not matter which CPU is the policy CPU at
the driver registration time and whether or not it is online all the
time, because the frequency QoS is per policy and not per CPU.
Fixes: 67d874c3b2 ("cpufreq: Register notifiers with the PM QoS framework")
Reported-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Reported-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Diagnosed-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/linux-pm/5ad2624194baa2f53acc1f1e627eb7684c577a19.1562210705.git.viresh.kumar@linaro.org/T/#md2d89e95906b8c91c15f582146173dce2e86e99f
Link: https://lore.kernel.org/linux-pm/20191017094612.6tbkwoq4harsjcqv@vireshk-i7/T/#m30d48cc23b9a80467fbaa16e30f90b3828a5a29b
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
No driver makes reference to these events now, remove them and the code
related to them.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This effectively reverts some changes made by commit f9f41e3ef9
("cpufreq: Remove policy create/remove notifiers").
We have a new use case for policy create/remove notifiers (for
allocating/freeing QoS requests per policy), so add them back.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* pm-cpufreq:
cpufreq: Make cpufreq_generic_init() return void
cpufreq: imx-cpufreq-dt: Add i.MX8MN support
cpufreq: Add QoS requests for userspace constraints
cpufreq: intel_pstate: Reuse refresh_frequency_limits()
cpufreq: Register notifiers with the PM QoS framework
PM / QoS: Add support for MIN/MAX frequency constraints
PM / QOS: Pass request type to dev_pm_qos_read_value()
PM / QOS: Rename __dev_pm_qos_read_value() and dev_pm_qos_raw_read_value()
PM / QOS: Pass request type to dev_pm_qos_{add|remove}_notifier()
It always returns 0 (success) and its return type should really be void.
Over that, many drivers have added error handling code based on its
return value, which is not required at all.
Change its return type to void and update all the callers.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This implements QoS requests to manage userspace configuration of min
and max frequency.
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: syzbot <syzbot+de771ae9390dffed7266@syzkaller.appspotmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The implementation of intel_pstate_update_max_freq() is quite similar to
refresh_frequency_limits(), lets reuse it.
Finding minimum of policy->user_policy.max and policy->cpuinfo.max_freq
in intel_pstate_update_max_freq() is redundant as cpufreq_set_policy()
will call the ->verify() callback of intel-pstate driver, which will do
this comparison anyway and so dropping it from
intel_pstate_update_max_freq() doesn't harm.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Register notifiers for min/max frequency constraints with the PM QoS
framework. The constraints are also taken into consideration in
cpufreq_set_policy().
This also relocates cpufreq_policy_put_kobj() as it is required to be
called from cpufreq_policy_alloc() now.
refresh_frequency_limits() is updated to avoid calling
cpufreq_set_policy() for inactive policies and handle_update() is
updated to have proper locking in place.
No constraints are added until now though.
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* pm-cpufreq:
cpufreq: Avoid calling cpufreq_verify_current_freq() from handle_update()
cpufreq: Consolidate cpufreq_update_current_freq() and __cpufreq_get()
cpufreq: Don't skip frequency validation for has_target() drivers
cpufreq: Use has_target() instead of !setpolicy
cpufreq: Remove redundant !setpolicy check
cpufreq: Move the IS_ENABLED(CPU_THERMAL) macro into a stub
cpufreq: s5pv210: Don't flood kernel log after cpufreq change
cpufreq: pcc-cpufreq: Fail initialization if driver cannot be registered
cpufreq: add driver for Raspberry Pi
cpufreq: Switch imx7d to imx-cpufreq-dt for speed grading
cpufreq: imx-cpufreq-dt: Remove global platform match list
cpufreq: brcmstb-avs-cpufreq: Fix types for voltage/frequency
cpufreq: brcmstb-avs-cpufreq: Fix initial command check
cpufreq: armada-37xx: Remove set but not used variable 'freq'
cpufreq: imx-cpufreq-dt: Fix no OPPs available on unfused parts
dt-bindings: imx-cpufreq-dt: Document opp-supported-hw usage
cpufreq: Add imx-cpufreq-dt driver
cpufreq_online() and cpufreq_offline() [un]register the driver as
a cooling device. This is done if the driver is flagged as a cooling
device in addition with an IS_ENABLED() check to compile out the branching
code.
Group this test in a stub function added in the cpufreq header instead
of having the IS_ENABLED() in the code.
Suggested-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, the notifiers are called once for each CPU of the policy->cpus
cpumask. It would be more optimal if the notifier can be called only
once and all the relevant information be provided to it. Out of the 23
drivers that register for the transition notifiers today, only 4 of them
do per-cpu updates and the callback for the rest can be called only once
for the policy without any impact.
This would also avoid multiple function calls to the notifier callbacks
and reduce multiple iterations of notifier core's code (which does
locking as well).
This patch adds pointer to the cpufreq policy to the struct
cpufreq_freqs, so the notifier callback has all the information
available to it with a single call. The five drivers which perform
per-cpu updates are updated to use the cpufreq policy. The freqs->cpu
field is redundant now and is removed.
Acked-by: David S. Miller <davem@davemloft.net> (sparc)
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
While the cpuinfo.max_freq value doesn't really matter for
intel_pstate in the active mode, in the passive mode it is used by
governors as the maximum physical frequency of the CPU and the
results of governor computations generally depend on it. Also it
is made available to user space via sysfs and it should match the
current HW configuration.
For this reason, make intel_pstate update cpuinfo.max_freq for all
CPUs if it detects a global change of turbo frequency settings from
"disable" to "enable" or the other way associated with a _PPC change
notification from the platform firmware.
Note that policy_is_inactive(), cpufreq_cpu_acquire(),
cpufreq_cpu_release(), and cpufreq_set_policy() need to be made
available to it for this purpose.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200759
Reported-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Tested-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
In some cases, the platform firmware disables or enables turbo
frequencies for all CPUs globally before triggering a _PPC change
notification for one of them. Obviously, that global change affects
all CPUs, not just the notified one, and it needs to be acted upon by
cpufreq.
The intel_pstate driver is able to detect such global changes of
the settings, but it also needs to update policy limits for all
CPUs if that happens, in particular if turbo frequencies are
enabled globally - to allow them to be used.
For this reason, introduce a new cpufreq driver callback to be
invoked on _PPC notifications, if present, instead of simply
calling cpufreq_update_policy() for the notified CPU and make
intel_pstate use it to trigger policy updates for all CPUs
in the system if global settings change.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200759
Reported-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Tested-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
The cpufreq core doesn't remove the cpufreq policy anymore on CPU
offline operation, rather that happens when the CPU device gets
unregistered from the kernel. This allows faster recovery when the CPU
comes back online. This is also very useful during system wide
suspend/resume where we offline all non-boot CPUs during suspend and
then bring them back on resume.
This commit takes the same idea a step ahead to allow drivers to do
light weight tear-down and bring-up during CPU offline and online
operations.
A new set of callbacks is introduced, online/offline(). online() gets
called when the first CPU of an inactive policy is brought up and
offline() gets called when all the CPUs of a policy are offlined.
The existing init/exit() callback get called on policy
creation/destruction. They also get called instead of online/offline()
callbacks if the online/offline() callbacks aren't provided.
This also moves around some code to get executed only for the new-policy
case going forward.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
All cpufreq drivers do similar things to register as a cooling device.
Provide a cpufreq driver flag so drivers can just ask the cpufreq core
to register the cooling device on their behalf. This allows us to get
rid of duplicated code in the drivers.
In order to allow this, we add a struct thermal_cooling_device pointer
to struct cpufreq_policy so that drivers don't need to store it in a
private data structure.
Suggested-by: Stephen Boyd <swboyd@chromium.org>
Suggested-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq_global_kobject is created using kobject_create_and_add()
helper, which assigns the kobj_type as dynamic_kobj_ktype and show/store
routines are set to kobj_attr_show() and kobj_attr_store().
These routines pass struct kobj_attribute as an argument to the
show/store callbacks. But all the cpufreq files created using the
cpufreq_global_kobject expect the argument to be of type struct
attribute. Things work fine currently as no one accesses the "attr"
argument. We may not see issues even if the argument is used, as struct
kobj_attribute has struct attribute as its first element and so they
will both get same address.
But this is logically incorrect and we should rather use struct
kobj_attribute instead of struct global_attr in the cpufreq core and
drivers and the show/store callbacks should take struct kobj_attribute
as argument instead.
This bug is caught using CFI CLANG builds in android kernel which
catches mismatch in function prototypes for such callbacks.
Reported-by: Donghee Han <dh.han@samsung.com>
Reported-by: Sangkyu Kim <skwith.kim@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Minor clean-up to use BIT() and keep checkpatch happy. Clean up the
comment formatting while we're at it to make it easier to read.
Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This routine checks if the CPU running this code belongs to the policy
of the target CPU or if not, can it do remote DVFS for it remotely. But
the current name of it implies as if it is only about doing remote
updates.
Rename it to make it more relevant.
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This isn't used anymore. Remove the helper and update documentation
accordingly.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
By design, cpufreq drivers are responsible for calling
cpufreq_frequency_table_cpuinfo() from their ->init()
callbacks to validate the frequency table.
However, if a cpufreq driver is buggy and fails to do so properly, it
lead to unexpected behavior of the driver or the cpufreq core at a
later point in time. It would be better if the core could
validate the frequency table during driver initialization.
To that end, introduce cpufreq_table_validate_and_sort() and make
the cpufreq core call it right after invoking the ->init() callback
of the driver and destroy the cpufreq policy if the table is invalid.
For the time being the validation of the table happens twice, once
from the driver and then from the core. The individual drivers will
be updated separately to drop table validation if they don't need it
for other reasons.
The frequency table is marked "sorted" or "unsorted" by the new helper
now instead of in cpufreq_table_validate_and_show(), as it should only
be done after validating the table (which the drivers won't do going
forward).
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Subject/changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pointer subtraction is slow and tedious. Therefore, replace all instances
where cpufreq_for_each_{valid_,}entry loops contained such substractions
with an iteration macro providing an index to the frequency_table entry.
Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Link: http://lkml.kernel.org/r/20180120020237.GM13338@ZenIV.linux.org.uk
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
After commit 890da9cf09 (Revert "x86: do not use cpufreq_quick_get()
for /proc/cpuinfo "cpu MHz"") the "cpu MHz" number in /proc/cpuinfo
on x86 can be either the nominal CPU frequency (which is constant)
or the frequency most recently requested by a scaling governor in
cpufreq, depending on the cpufreq configuration. That is somewhat
inconsistent and is different from what it was before 4.13, so in
order to restore the previous behavior, make it report the current
CPU frequency like the scaling_cur_freq sysfs file in cpufreq.
To that end, modify the /proc/cpuinfo implementation on x86 to use
aperfmperf_snapshot_khz() to snapshot the APERF and MPERF feedback
registers, if available, and use their values to compute the CPU
frequency to be reported as "cpu MHz".
However, do that carefully enough to avoid accumulating delays that
lead to unacceptable access times for /proc/cpuinfo on systems with
many CPUs. Run aperfmperf_snapshot_khz() once on all CPUs
asynchronously at the /proc/cpuinfo open time, add a single delay
upfront (if necessary) at that point and simply compute the current
frequency while running show_cpuinfo() for each individual CPU.
Also, to avoid slowing down /proc/cpuinfo accesses too much, reduce
the default delay between consecutive APERF and MPERF reads to 10 ms,
which should be sufficient to get large enough numbers for the
frequency computation in all cases.
Fixes: 890da9cf09 (Revert "x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz"")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Frequency-invariant accounting support based on the ratio of current
frequency and maximum supported frequency is an optional feature an arch
can implement.
Since there are cpufreq drivers (e.g. cpufreq-dt) which can be build for
different arch's a default implementation of the frequency-invariance
setter function arch_set_freq_scale() is needed.
This default implementation is an empty weak function which will be
overwritten by a strong function in case the arch provides one.
The setter function passes the cpumask of related (to the frequency
change) cpus (online and offline cpus), the (new) current frequency and
the maximum supported frequency.
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* pm-cpufreq-sched:
cpufreq: schedutil: Always process remote callback with slow switching
cpufreq: schedutil: Don't restrict kthread to related_cpus unnecessarily
cpufreq: Return 0 from ->fast_switch() on errors
cpufreq: Simplify cpufreq_can_do_remote_dvfs()
cpufreq: Process remote callbacks from any CPU if the platform permits
sched: cpufreq: Allow remote cpufreq callbacks
cpufreq: schedutil: Use unsigned int for iowait boost
cpufreq: schedutil: Make iowait boost more energy efficient
The if () in cpufreq_can_do_remote_dvfs() is superfluous, so drop
it and simply return the value of the expression under it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
On many platforms, CPUs can do DVFS across cpufreq policies. i.e CPU
from policy-A can change frequency of CPUs belonging to policy-B.
This is quite common in case of ARM platforms where we don't
configure any per-cpu register.
Add a flag to identify such platforms and update
cpufreq_can_do_remote_dvfs() to allow remote callbacks if this flag is
set.
Also enable the flag for cpufreq-dt driver which is used only on ARM
platforms currently.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
With Android UI and benchmarks the latency of cpufreq response to
certain scheduling events can become very critical. Currently, callbacks
into cpufreq governors are only made from the scheduler if the target
CPU of the event is the same as the current CPU. This means there are
certain situations where a target CPU may not run the cpufreq governor
for some time.
One testcase to show this behavior is where a task starts running on
CPU0, then a new task is also spawned on CPU0 by a task on CPU1. If the
system is configured such that the new tasks should receive maximum
demand initially, this should result in CPU0 increasing frequency
immediately. But because of the above mentioned limitation though, this
does not occur.
This patch updates the scheduler core to call the cpufreq callbacks for
remote CPUs as well.
The schedutil, ondemand and conservative governors are updated to
process cpufreq utilization update hooks called for remote CPUs where
the remote CPU is managed by the cpufreq policy of the local CPU.
The intel_pstate driver is updated to always reject remote callbacks.
This is tested with couple of usecases (Android: hackbench, recentfling,
galleryfling, vellamo, Ubuntu: hackbench) on ARM hikey board (64 bit
octa-core, single policy). Only galleryfling showed minor improvements,
while others didn't had much deviation.
The reason being that this patch only targets a corner case, where
following are required to be true to improve performance and that
doesn't happen too often with these tests:
- Task is migrated to another CPU.
- The task has high demand, and should take the target CPU to higher
OPPs.
- And the target CPU doesn't call into the cpufreq governor until the
next tick.
Based on initial work from Steve Muckle.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The policy->transition_latency field is used for multiple purposes
today and its not straight forward at all. This is how it is used:
A. Set the correct transition_latency value.
B. Set it to CPUFREQ_ETERNAL because:
1. We don't want automatic dynamic switching (with
ondemand/conservative) to happen at all.
2. We don't know the transition latency.
This patch handles the B.1. case in a more readable way. A new flag for
the cpufreq drivers is added to disallow use of cpufreq governors which
have dynamic_switching flag set.
All the current cpufreq drivers which are setting transition_latency
unconditionally to CPUFREQ_ETERNAL are updated to use it. They don't
need to set transition_latency anymore.
There shouldn't be any functional change after this patch.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There is no limitation in the ondemand or conservative governors which
disallow the transition_latency to be greater than 10 ms.
The max_transition_latency field is rather used to disallow automatic
dynamic frequency switching for platforms which didn't wanted these
governors to run.
Replace max_transition_latency with a boolean (dynamic_switching) and
check for transition_latency == CPUFREQ_ETERNAL along with that. This
makes it pretty straight forward to read/understand now.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The policy->transition_delay_us field is used only by the schedutil
governor currently, and this field describes how fast the driver wants
the cpufreq governor to change CPUs frequency. It should rather be a
common thing across all governors, as it doesn't have any schedutil
dependency here.
Create a new helper cpufreq_policy_transition_delay_us() to get the
transition delay across all governors.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq core and governors aren't supposed to set a limit on how
fast we want to try changing the frequency. This is currently done for
the legacy governors with help of min_sampling_rate.
At worst, we may end up setting the sampling rate to a value lower than
the rate at which frequency can be changed and then one of the CPUs in
the policy will be only changing frequency for ever.
But that is something for the user to decide and there is no need to
have special handling for such cases in the core. Leave it for the user
to figure out.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull thermal management updates from Zhang Rui:
- Improve thermal cpu_cooling interaction with cpufreq core.
The cpu_cooling driver is designed to use CPU frequency scaling to
avoid high thermal states for a platform. But it wasn't glued really
well with cpufreq core.
For example clipped-cpus is copied from the policy structure and its
much better to use the policy->cpus (or related_cpus) fields directly
as they may have got updated. Not that things were broken before this
series, but they can be optimized a bit more.
This series tries to improve interactions between cpufreq core and
cpu_cooling driver and does some fixes/cleanups to the cpu_cooling
driver. (Viresh Kumar)
- A couple of fixes and cleanups in thermal core and imx, hisilicon,
bcm_2835, int340x thermal drivers. (Arvind Yadav, Dan Carpenter,
Sumeet Pawnikar, Srinivas Pandruvada, Willy WOLFF)
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux: (24 commits)
thermal: bcm2835: fix an error code in probe()
thermal: hisilicon: Handle return value of clk_prepare_enable
thermal: imx: Handle return value of clk_prepare_enable
thermal: int340x: check for sensor when PTYP is missing
Thermal/int340x: Fix few typos and kernel-doc style
thermal: fix source code documentation for parameters
thermal: cpu_cooling: Replace kmalloc with kmalloc_array
thermal: cpu_cooling: Rearrange struct cpufreq_cooling_device
thermal: cpu_cooling: 'freq' can't be zero in cpufreq_state2power()
thermal: cpu_cooling: don't store cpu_dev in cpufreq_cdev
thermal: cpu_cooling: get_level() can't fail
thermal: cpu_cooling: create structure for idle time stats
thermal: cpu_cooling: merge frequency and power tables
thermal: cpu_cooling: get rid of 'allowed_cpus'
thermal: cpu_cooling: OPPs are registered for all CPUs
thermal: cpu_cooling: store cpufreq policy
cpufreq: create cpufreq_table_count_valid_entries()
thermal: cpu_cooling: use cpufreq_policy to register cooling device
thermal: cpu_cooling: get rid of a variable in cpufreq_set_cur_state()
thermal: cpu_cooling: remove cpufreq_cooling_get_level()
...
The goal of this change is to give users a uniform and meaningful
result when they read /sys/...cpufreq/scaling_cur_freq
on modern x86 hardware, as compared to what they get today.
Modern x86 processors include the hardware needed
to accurately calculate frequency over an interval --
APERF, MPERF, and the TSC.
Here we provide an x86 routine to make this calculation
on supported hardware, and use it in preference to any
driver driver-specific cpufreq_driver.get() routine.
MHz is computed like so:
MHz = base_MHz * delta_APERF / delta_MPERF
MHz is the average frequency of the busy processor
over a measurement interval. The interval is
defined to be the time between successive invocations
of aperfmperf_khz_on_cpu(), which are expected to to
happen on-demand when users read sysfs attribute
cpufreq/scaling_cur_freq.
As with previous methods of calculating MHz,
idle time is excluded.
base_MHz above is from TSC calibration global "cpu_khz".
This x86 native method to calculate MHz returns a meaningful result
no matter if P-states are controlled by hardware or firmware
and/or if the Linux cpufreq sub-system is or is-not installed.
When this routine is invoked more frequently, the measurement
interval becomes shorter. However, the code limits re-computation
to 10ms intervals so that average frequency remains meaningful.
Discerning users are encouraged to take advantage of
the turbostat(8) utility, which can gracefully handle
concurrent measurement intervals of arbitrary length.
Signed-off-by: Len Brown <len.brown@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We need such a routine at two places already, lets create one.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Make the schedutil governor take the initial (default) value of the
rate_limit_us sysfs attribute from the (new) transition_delay_us
policy parameter (to be set by the scaling driver).
That will allow scaling drivers to make schedutil use smaller default
values of rate_limit_us and reduce the default average time interval
between consecutive frequency changes.
Make intel_pstate set transition_delay_us to 500.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Those were added by:
commit fcd7af917a ("cpufreq: stats: handle cpufreq_unregister_driver()
and suspend/resume properly")
but aren't used anymore since:
commit 1aefc75b24 ("cpufreq: stats: Make the stats code non-modular").
Remove them. Also remove the redundant parameter to the respective
routines.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The return value of cpufreq_update_policy() is never used, so make
it void.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Allow CPUfreq statistics to be cleared by writing anything to
/sys/.../cpufreq/stats/reset.
Signed-off-by: Markus Mayer <mmayer@broadcom.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Skip invalid entries when searching the frequency. This fixes cpufreq
at least on loongson2 MIPS board.
Fixes: da0c6dc00c (cpufreq: Handle sorted frequency tables more efficiently)
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.8+ <stable@vger.kernel.org> # 4.8+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cpufreq governors may need to know what a particular target frequency
maps to in the driver without necessarily wanting to set the frequency.
Support this operation via a new cpufreq API,
cpufreq_driver_resolve_freq(). This API returns the lowest driver
frequency equal or greater than the target frequency
(CPUFREQ_RELATION_L), subject to any policy (min/max) or driver
limitations. The mapping is also cached in the policy so that a
subsequent fast_switch operation can avoid repeating the same lookup.
The API will call a new cpufreq driver callback, resolve_freq(), if it
has been registered by the driver. Otherwise the frequency is resolved
via cpufreq_frequency_table_target(). Rather than require ->target()
style drivers to provide a resolve_freq() callback it is left to the
caller to ensure that the driver implements this callback if necessary
to use cpufreq_driver_resolve_freq().
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Steve Muckle <smuckle@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq drivers aren't required to provide a sorted frequency table
today, and even the ones which provide a sorted table aren't handled
efficiently by cpufreq core.
This patch adds infrastructure to verify if the freq-table provided by
the drivers is sorted or not, and use efficient helpers if they are
sorted.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
