24 Aug, 2020
1 commit
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Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through
Signed-off-by: Gustavo A. R. Silva
04 Mar, 2020
1 commit
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The target_value field in struct pm_qos_constraints is used for
lockless access to the effective constraint value of a given QoS
list, so the readers of it cannot expect it to always reflect the
most recent effective constraint value. However, they can and do
expect it to be equal to a valid effective constraint value computed
at a certain time in the past (event though it may not be the most
recent one), so add READ|WRITE_ONCE() annotations around the
target_value accesses to prevent the compiler from possibly causing
that expectation to be unmet by generating code in an exceptionally
convoluted way.Signed-off-by: Qian Cai
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki
14 Feb, 2020
3 commits
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Because cpuidle is the only user of the effective constraint coming
from the CPU latency QoS, add #ifdef CONFIG_CPU_IDLE around that code
to avoid building it unnecessarily.Signed-off-by: Rafael J. Wysocki
Reviewed-by: Ulf Hansson
Reviewed-by: Amit Kucheria
Tested-by: Amit Kucheria -
Update the file information comments in include/linux/pm_qos.h
and kernel/power/qos.c by adding titles along with copyright and
authors information to them and changing the qos.c description to
better reflect its contents (outdated information is dropped from
it in particular).Signed-off-by: Rafael J. Wysocki
Reviewed-by: Ulf Hansson
Reviewed-by: Amit Kucheria
Tested-by: Amit Kucheria -
Drop the PM QoS classes enum including PM_QOS_CPU_DMA_LATENCY,
drop the wrappers around pm_qos_request(), pm_qos_request_active(),
and pm_qos_add/update/remove_request() introduced previously, rename
these functions, respectively, to cpu_latency_qos_limit(),
cpu_latency_qos_request_active(), and
cpu_latency_qos_add/update/remove_request(), and update their
kerneldoc comments. [While at it, drop some useless comments from
these functions.]No intentional functional impact.
Signed-off-by: Rafael J. Wysocki
Reviewed-by: Ulf Hansson
Reviewed-by: Amit Kucheria
Tested-by: Amit Kucheria
13 Feb, 2020
11 commits
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Change the return type of pm_qos_request() to be the same as the
one of pm_qos_read_value() called by it internally and stop exporting
it to modules (because its only caller, cpuidle, is not modular).Also move the pm_qos_read_value() header away from the CPU latency
QoS API function headers in pm_qos.h (because it technically does
not belong to that API).No intentional functional impact.
Signed-off-by: Rafael J. Wysocki
Reviewed-by: Ulf Hansson
Reviewed-by: Amit Kucheria
Tested-by: Amit Kucheria -
Modify the definitions of the CPU latency QoS trace events to take
one argument (since PM_QOS_CPU_DMA_LATENCY is always passed as the
pm_qos_class argument to them) and update the documentation of them
accordingly (while at it, make it explicitly mention CPU latency QoS
and relocate it after the device PM QoS trace events documentation).The names and output format of the trace events do not change to
preserve user space compatibility.No intentional functional impact.
Signed-off-by: Rafael J. Wysocki
Reviewed-by: Ulf Hansson
Reviewed-by: Amit Kucheria
Tested-by: Amit Kucheria -
First, rename PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE to
PM_QOS_CPU_LATENCY_DEFAULT_VALUE and update all of the code
referring to it accordingly.Next, rename cpu_dma_constraints to cpu_latency_constraints, move
the definition of it closer to the functions referring to it and
update all of them accordingly. [While at it, add a comment to mark
the start of the code related to the CPU latency QoS.]Finally, rename the pm_qos_power_*() family of functions and
pm_qos_power_fops to cpu_latency_qos_*() and cpu_latency_qos_fops,
respectively, and update the definition of cpu_latency_qos_miscdev.
[While at it, update the miscdev interface code start comment.]No intentional functional impact.
Signed-off-by: Rafael J. Wysocki
Reviewed-by: Ulf Hansson
Acked-by: Greg Kroah-Hartman
Reviewed-by: Amit Kucheria
Tested-by: Amit Kucheria -
Notice that pm_qos_remove_notifier() is not used at all and the only
caller of pm_qos_add_notifier() is the cpuidle core, which only needs
the PM_QOS_CPU_DMA_LATENCY notifier to invoke wake_up_all_idle_cpus()
upon changes of the PM_QOS_CPU_DMA_LATENCY target value.First, to ensure that wake_up_all_idle_cpus() will be called
whenever the PM_QOS_CPU_DMA_LATENCY target value changes, modify the
pm_qos_add/update/remove_request() family of functions to check if
the effective constraint for the PM_QOS_CPU_DMA_LATENCY has changed
and call wake_up_all_idle_cpus() directly in that case.Next, drop the PM_QOS_CPU_DMA_LATENCY notifier from cpuidle as it is
not necessary any more.Finally, drop both pm_qos_add_notifier() and pm_qos_remove_notifier(),
as they have no callers now, along with cpu_dma_lat_notifier which is
only used by them.Signed-off-by: Rafael J. Wysocki
Reviewed-by: Ulf Hansson
Reviewed-by: Amit Kucheria
Tested-by: Amit Kucheria -
First, change the definition of struct pm_qos_request so that it
contains a struct pm_qos_constraints pointer (called "qos") instead
of a PM QoS class number (in preparation for dropping the PM QoS
classes concept altogether going forward) and move its definition
(along with the definition of struct pm_qos_flags_request that does
not change) after the definition of struct pm_qos_constraints.Next, drop the definition of struct pm_qos_object and the null_pm_qos
and cpu_dma_pm_qos variables of that type along with pm_qos_array[]
holding pointers to them and change the code to refer to the
pm_qos_constraints structure directly or to use the new qos pointer
in struct pm_qos_request for that instead of going through
pm_qos_array[] to access it. Also update kerneldoc comments that
mention pm_qos_class to refer to PM_QOS_CPU_DMA_LATENCY directly
instead.Finally, drop register_pm_qos_misc(), introduce cpu_latency_qos_miscdev
(with the name field set to "cpu_dma_latency") to implement the
CPU latency QoS interface in /dev/ and register it directly from
pm_qos_power_init().After these changes the notion of PM QoS classes remains only in the
API (in the form of redundant function parameters that are ignored)
and in the definitions of PM QoS trace events.While at it, some redundant local variables are dropped etc.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki
Reviewed-by: Ulf Hansson
Reviewed-by: Amit Kucheria
Tested-by: Amit Kucheria -
Reorder the code to avoid using extra function header declarations
for the pm_qos_power_*() family of functions and drop those
declarations.Also clean up the internals of those functions to consolidate checks,
avoid using redundant local variables and similar.No intentional functional impact.
Signed-off-by: Rafael J. Wysocki
Reviewed-by: Ulf Hansson
Reviewed-by: Amit Kucheria
Tested-by: Amit Kucheria -
After commit c3082a674f46 ("PM: QoS: Get rid of unused flags") the
only global PM QoS class in use is PM_QOS_CPU_DMA_LATENCY, so it
does not really make sense to iterate over global QoS classes
anywhere, since there is only one.Remove iterations over global QoS classes from the code and use
PM_QOS_CPU_DMA_LATENCY as the target class directly where needed.No intentional functional impact.
Signed-off-by: Rafael J. Wysocki
Reviewed-by: Ulf Hansson
Reviewed-by: Amit Kucheria
Tested-by: Amit Kucheria -
Move the definition of pm_qos_read_value() before the one of
pm_qos_get_value() and add a kerneldoc comment to it (as it is
not static).Also replace the BUG() in pm_qos_get_value() with WARN() (to
prevent the kernel from crashing if an unknown PM QoS type is
used by mistake) and drop the comment next to it that is not
necessary any more.Additionally, drop the unnecessary inline modifier from the header
of pm_qos_set_value().Signed-off-by: Rafael J. Wysocki
Reviewed-by: Ulf Hansson
Reviewed-by: Amit Kucheria
Tested-by: Amit Kucheria -
Clean up the pm_qos_update_target() function:
* Update its kerneldoc comment.
* Drop the redundant ret local variable from it.
* Reorder definitions of local variables in it.
* Update a comment in it.Also update the kerneldoc comment of pm_qos_update_flags() (e.g.
notifiers are not called by it any more) and add one emtpy line
to its body (for more visual clarity).No intentional functional impact.
Signed-off-by: Rafael J. Wysocki
Reviewed-by: Ulf Hansson
Reviewed-by: Amit Kucheria
Tested-by: Amit Kucheria -
The PM_QOS_SUM QoS type is not used, so drop it along with the
code referring to it in pm_qos_get_value() and the related local
variables in there.No intentional functional impact.
Signed-off-by: Rafael J. Wysocki
Reviewed-by: Ulf Hansson
Reviewed-by: Amit Kucheria
Tested-by: Amit Kucheria -
The pm_qos_update_request_timeout() function is not called from
anywhere, so drop it along with the work member in struct
pm_qos_request needed by it.Also drop the useless pm_qos_update_request_timeout trace event
that is only triggered by that function (so it never triggers at
all) and update the trace events documentation accordingly.Signed-off-by: Rafael J. Wysocki
Reviewed-by: Ulf Hansson
Reviewed-by: Amit Kucheria
Tested-by: Amit Kucheria
12 Feb, 2020
1 commit
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After commit c3082a674f46 ("PM: QoS: Get rid of unused flags") the
only global PM QoS class in use is PM_QOS_CPU_DMA_LATENCY and the
existing PM QoS debugfs interface has become overly complicated (as
it takes other potentially possible PM QoS classes that are not there
any more into account). It is also not particularly useful (the
"type" of the PM_QOS_CPU_DMA_LATENCY is known, its aggregate value
can be read from /dev/cpu_dma_latency and the number of requests in
the queue does not really matter) and there are no known users
depending on it. Moreover, there are dedicated trace events that
can be used for tracking PM QoS usage with much higher precision.For these reasons, drop the PM QoS debugfs interface altogether.
Signed-off-by: Rafael J. Wysocki
Reviewed-by: Ulf Hansson
29 Nov, 2019
1 commit
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Support for adding per-device frequency limits was removed in
commit 2aac8bdf7a0f ("PM: QoS: Drop frequency QoS types from device PM QoS")
after cpufreq switched to use a new "freq_constraints" construct.Restore support for per-device freq limits but base this upon
freq_constraints. This is primarily meant to be used by the devfreq
subsystem.This removes the "static" marking on freq_qos_apply but does not export
it for modules.Signed-off-by: Leonard Crestez
Reviewed-by: Matthias Kaehlcke
Tested-by: Matthias Kaehlcke
Signed-off-by: Rafael J. Wysocki
20 Nov, 2019
1 commit
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Switching cpufreq drivers (or switching operation modes of the
intel_pstate driver from "active" to "passive" and vice versa)
does not work on some x86 systems with ACPI after commit
3000ce3c52f8 ("cpufreq: Use per-policy frequency QoS"), because
the ACPI _PPC and thermal code uses the same frequency QoS request
object for a given CPU every time a cpufreq driver is registered
and freq_qos_remove_request() does not invalidate the request after
removing it from its QoS list, so freq_qos_add_request() complains
and fails when that request is passed to it again.Fix the issue by modifying freq_qos_remove_request() to clear the qos
and type fields of the frequency request pointed to by its argument
after removing it from its QoS list so as to invalidate it.Fixes: 3000ce3c52f8 ("cpufreq: Use per-policy frequency QoS")
Reported-and-tested-by: Doug Smythies
Signed-off-by: Rafael J. Wysocki
Acked-by: Viresh Kumar
21 Oct, 2019
1 commit
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Introduce frequency QoS, based on the "raw" low-level PM QoS, to
represent min and max frequency requests and aggregate constraints.The min and max frequency requests are to be represented by
struct freq_qos_request objects and the aggregate constraints are to
be represented by struct freq_constraints objects. The latter are
expected to be initialized with the help of freq_constraints_init().The freq_qos_read_value() helper is defined to retrieve the aggregate
constraints values from a given struct freq_constraints object and
there are the freq_qos_add_request(), freq_qos_update_request() and
freq_qos_remove_request() helpers to manipulate the min and max
frequency requests. It is assumed that the the helpers will not
run concurrently with each other for the same struct freq_qos_request
object, so if that may be the case, their uses must ensure proper
synchronization between them (e.g. through locking).In addition, freq_qos_add_notifier() and freq_qos_remove_notifier()
are provided to add and remove notifiers that will trigger on aggregate
constraint changes to and from a given struct freq_constraints object,
respectively.Signed-off-by: Rafael J. Wysocki
Acked-by: Viresh Kumar
21 Aug, 2019
1 commit
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The network_latency and network_throughput flags for PM-QoS have not
found much use in drivers or in userspace since they were introduced.Commit 4a733ef1bea7 ("mac80211: remove PM-QoS listener") removed the
only user PM_QOS_NETWORK_LATENCY in the kernel a while ago and there
don't seem to be any userspace tools using the character device files
either.PM_QOS_MEMORY_BANDWIDTH was never even added to the trace events.
Remove all the flags except cpu_dma_latency.
Signed-off-by: Amit Kucheria
Acked-by: Pavel Machek
Signed-off-by: Rafael J. Wysocki
21 May, 2019
1 commit
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Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have EXPORT_.*_SYMBOL_GPL inside which was used in the
initial scan/conversion to ignore the fileThese files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:GPL-2.0-only
Signed-off-by: Thomas Gleixner
Signed-off-by: Greg Kroah-Hartman
23 Jan, 2019
1 commit
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When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.Signed-off-by: Greg Kroah-Hartman
Signed-off-by: Rafael J. Wysocki
30 Nov, 2018
1 commit
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Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.
Signed-off-by: Yangtao Li
Acked-by: Pavel Machek
Signed-off-by: Rafael J. Wysocki
29 May, 2018
1 commit
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The extra forward declaration of pm_qos_get_value() is redundant, so
drop it.Signed-off-by: Rafael J. Wysocki
09 Apr, 2018
1 commit
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In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.Signed-off-by: Gustavo A. R. Silva
Acked-by: Pavel Machek
Signed-off-by: Rafael J. Wysocki
03 Oct, 2017
1 commit
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Convert printks to pr_.
Miscellanea:
o Use pr_fmt with "PM:" and remove "PM: " from format strings
o Coalesce format strings and realign format arguments
o Convert an embedded incorrect function name to "%s: ", __func__
o Convert a couple multi-line formats to multiple pr_ callsSigned-off-by: Joe Perches
Acked-by: Pavel Machek
Signed-off-by: Rafael J. Wysocki
18 Sep, 2016
1 commit
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Now that workqueue can handle work item queueing/cancelling from very
early during boot, there is no need to gate cancel_delayed_work_sync()
while !keventd_up(). Remove it.Signed-off-by: Tejun Heo
Acked-by: Rafael J. Wysocki
Cc: Qiao Zhou
05 Sep, 2016
1 commit
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of_clk_init() ends up calling into pm_qos_update_request() very early
during boot where irq is expected to stay disabled.
pm_qos_update_request() uses cancel_delayed_work_sync() which
correctly assumes that irq is enabled on invocation and
unconditionally disables and re-enables it.Gate cancel_delayed_work_sync() invocation with kevented_up() to avoid
enabling irq unexpectedly during early boot.Signed-off-by: Tejun Heo
Reported-and-tested-by: Qiao Zhou
Link: http://lkml.kernel.org/r/d2501c4c-8e7b-bea3-1b01-000b36b5dfe9@asrmicro.com
Signed-off-by: Rafael J. Wysocki
24 Jan, 2015
1 commit
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PM QoS requests are notoriously hard to debug and made even
more so due to their highly dynamic nature. Having visibility
into the internal data representation per constraint allows
us to have much better appreciation of potential issues or
bad usage by drivers in the system.So introduce for all classes of PM QoS, an entry in
/sys/kernel/debug/pm_qos that shall show all the current
requests as well as the snapshot of the value these requests
boil down to. For example:
==> /sys/kernel/debug/pm_qos/cpu_dma_latency /sys/kernel/debug/pm_qos/memory_bandwidth
Signed-off-by: Dave Gerlach
Acked-by: Kevin Hilman
Signed-off-by: Rafael J. Wysocki
25 Sep, 2014
1 commit
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Also adds a class type PM_QOS_SUM that aggregates the values by summing them.
It can be used by memory controllers to calculate the optimum clock frequency
based on the bandwidth needs of the different memory clients.Signed-off-by: Tomeu Vizoso
Acked-by: Pavel Machek
Signed-off-by: Rafael J. Wysocki
11 Feb, 2014
2 commits
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Add a new latency tolerance device PM QoS type to be use for
specifying active state (RPM_ACTIVE) memory access (DMA) latency
tolerance requirements for devices. It may be used to prevent
hardware from choosing overly aggressive energy-saving operation
modes (causing too much latency to appear) for the whole platform.This feature reqiures hardware support, so it only will be
available for devices having a new .set_latency_tolerance()
callback in struct dev_pm_info populated, in which case the
routine pointed to by it should implement whatever is necessary
to transfer the effective requirement value to the hardware.Whenever the effective latency tolerance changes for the device,
its .set_latency_tolerance() callback will be executed and the
effective value will be passed to it. If that value is negative,
which means that the list of latency tolerance requirements for
the device is empty, the callback is expected to switch the
underlying hardware latency tolerance control mechanism to an
autonomous mode if available. If that value is PM_QOS_LATENCY_ANY,
in turn, and the hardware supports a special "no requirement"
setting, the callback is expected to use it. That allows software
to prevent the hardware from automatically updating the device's
latency tolerance in response to its power state changes (e.g. during
transitions from D3cold to D0), which generally may be done in the
autonomous latency tolerance control mode.If .set_latency_tolerance() is present for the device, a new
pm_qos_latency_tolerance_us attribute will be present in the
devivce's power directory in sysfs. Then, user space can use
that attribute to specify its latency tolerance requirement for
the device, if any. Writing "any" to it means "no requirement, but
do not let the hardware control latency tolerance" and writing
"auto" to it allows the hardware to be switched to the autonomous
mode if there are no other requirements from the kernel side in the
device's list.This changeset includes a fix from Mika Westerberg.
Signed-off-by: Rafael J. Wysocki
-
Add a new field, no_constraints_value, to struct pm_qos_constraints
representing a list of PM QoS constraint requests to be returned by
pm_qos_get_value() when that list of requests is empty.That field will be equal to default_value for all of the existing
global PM QoS classes and for the resume latency device PM QoS type,
but it will be different from default_value for the new latency
tolerance device PM QoS type introduced by the next changeset.Signed-off-by: Rafael J. Wysocki
18 Oct, 2013
1 commit
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Let kstrtos32_from_user() do the necessary calls and checks.
Signed-off-by: Andy Shevchenko
Signed-off-by: Rafael J. Wysocki
14 Aug, 2013
1 commit
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pm_qos_update_request_timeout() updates a qos and then schedules
a delayed work item to bring the qos back down to the default
after the timeout. When the work item runs, pm_qos_work_fn() will
call pm_qos_update_request() and deadlock because it tries to
cancel itself via cancel_delayed_work_sync(). Future callers of
that qos will also hang waiting to cancel the work that is
canceling itself. Let's extract the little bit of code that does
the real work of pm_qos_update_request() and call it from the
work function so that we don't deadlock.Before ed1ac6e (PM: don't use [delayed_]work_pending()) this didn't
happen because the work function wouldn't try to cancel itself.Signed-off-by: Stephen Boyd
Reviewed-by: Tejun Heo
Cc: 3.9+ # 3.9+
Signed-off-by: Rafael J. Wysocki
24 Jun, 2013
2 commits
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Adds tracepoints to pm_qos_add_request, pm_qos_update_request,
pm_qos_remove_request, and pm_qos_update_request_timeout.
It's useful for checking pm_qos_class, value, and timeout_us.Signed-off-by: Sahara
Signed-off-by: Rafael J. Wysocki -
This patch adds tracepoints to pm_qos_update_target and
pm_qos_update_flags. It's useful for checking pm qos action,
previous value and current value.Signed-off-by: Sahara
Signed-off-by: Rafael J. Wysocki
21 Jun, 2013
1 commit
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The valid start index for pm_qos_array is not 0, but
PM_QOS_CPU_DMA_LATENCY. There is a null_pm_qos at index 0 of
pm_qos_array. However, null_pm_qos is not created as misc device so
that inclusion of 0 index for checking pm_qos_class especially for
file operations is not proper here.[rjw: Changelog, a bit]
Signed-off-by: Sahara
Signed-off-by: Rafael J. Wysocki
26 Jan, 2013
1 commit
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There's no need to test whether a (delayed) work item is pending
before queueing, flushing or cancelling it, so remove work_pending()
tests used in those cases.Signed-off-by: Tejun Heo
Signed-off-by: Rafael J. Wysocki
30 Nov, 2012
1 commit
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* pm-sleep:
PM / Freezer: Fixup compile error of try_to_freeze_nowarn()
driver core / PM: move the calling to device_pm_remove behind the calling to bus_remove_device
PM / Hibernate: use rb_entry
PM / sysfs: replace strict_str* with kstrto*