linux-stable.git/drivers/cpuidle, branch v5.3.17

cpuidle: teo: Fix "early hits" handling for disabled idle states

2019-12-17T19:07:51+00:00

commit 159e48560f51d9c2aa02d762a18cd24f7868ab27 upstream.

The TEO governor uses idle duration "bins" defined in accordance with
the CPU idle states table provided by the driver, so that each "bin"
covers the idle duration range between the target residency of the
idle state corresponding to it and the target residency of the closest
deeper idle state.  The governor collects statistics for each bin
regardless of whether or not the idle state corresponding to it is
currently enabled.

In particular, the "early hits" metric measures the likelihood of a
situation in which the idle duration measured after wakeup falls into
to given bin, but the time till the next timer (sleep length) falls
into a bin corresponding to one of the deeper idle states.  It is
used when the "hits" and "misses" metrics indicate that the state
"matching" the sleep length should not be selected, so that the state
with the maximum "early hits" value is selected instead of it.

If the idle state corresponding to the given bin is disabled, it
cannot be selected and if it turns out to be the one that should be
selected, a shallower idle state needs to be used instead of it.
Nevertheless, the metrics collected for the bin corresponding to it
are still valid and need to be taken into account as though that
state had not been disabled.

As far as the "early hits" metric is concerned, teo_select() tries to
take disabled states into account, but the state index corresponding
to the maximum "early hits" value computed by it may be incorrect.
Namely, it always uses the index of the previous maximum "early hits"
state then, but there may be enabled idle states closer to the
disabled one in question.  In particular, if the current candidate
state (whose index is the idx value) is closer to the disabled one
and the "early hits" value of the disabled state is greater than the
current maximum, the index of the current candidate state (idx)
should replace the "maximum early hits state" index.

Modify the code to handle that case correctly.

Fixes: b26bf6ab716f ("cpuidle: New timer events oriented governor for tickless systems")
Reported-by: Doug Smythies 
Signed-off-by: Rafael J. Wysocki 
Cc: 5.1+  # 5.1+
Signed-off-by: Greg Kroah-Hartman

cpuidle: teo: Consider hits and misses metrics of disabled states

2019-12-17T19:07:51+00:00

commit e43dcf20215f0287ea113102617ca04daa76b70e upstream.

The TEO governor uses idle duration "bins" defined in accordance with
the CPU idle states table provided by the driver, so that each "bin"
covers the idle duration range between the target residency of the
idle state corresponding to it and the target residency of the closest
deeper idle state.  The governor collects statistics for each bin
regardless of whether or not the idle state corresponding to it is
currently enabled.

In particular, the "hits" and "misses" metrics measure the likelihood
of a situation in which both the time till the next timer (sleep
length) and the idle duration measured after wakeup fall into the
given bin.  Namely, if the "hits" value is greater than the "misses"
one, that situation is more likely than the one in which the sleep
length falls into the given bin, but the idle duration measured after
wakeup falls into a bin corresponding to one of the shallower idle
states.

If the idle state corresponding to the given bin is disabled, it
cannot be selected and if it turns out to be the one that should be
selected, a shallower idle state needs to be used instead of it.
Nevertheless, the metrics collected for the bin corresponding to it
are still valid and need to be taken into account as though that
state had not been disabled.

For this reason, make teo_select() always use the "hits" and "misses"
values of the idle duration range that the sleep length falls into
even if the specific idle state corresponding to it is disabled and
if the "hits" values is greater than the "misses" one, select the
closest enabled shallower idle state in that case.

Fixes: b26bf6ab716f ("cpuidle: New timer events oriented governor for tickless systems")
Signed-off-by: Rafael J. Wysocki 
Cc: 5.1+  # 5.1+
Signed-off-by: Greg Kroah-Hartman

cpuidle: teo: Rename local variable in teo_select()

2019-12-17T19:07:50+00:00

commit 4f690bb8ce4cc5d3fabe3a8e9c2401de1554cdc1 upstream.

Rename a local variable in teo_select() in preparation for subsequent
code modifications, no intentional impact.

Signed-off-by: Rafael J. Wysocki 
Cc: 5.1+  # 5.1+
Signed-off-by: Greg Kroah-Hartman

cpuidle: teo: Ignore disabled idle states that are too deep

2019-12-17T19:07:50+00:00

commit 069ce2ef1a6dd84cbd4d897b333e30f825e021f0 upstream.

Prevent disabled CPU idle state with target residencies beyond the
anticipated idle duration from being taken into account by the TEO
governor.

Fixes: b26bf6ab716f ("cpuidle: New timer events oriented governor for tickless systems")
Signed-off-by: Rafael J. Wysocki 
Cc: 5.1+  # 5.1+
Signed-off-by: Greg Kroah-Hartman

cpuidle: Do not unset the driver if it is there already

2019-12-17T19:07:50+00:00

commit 918c1fe9fbbe46fcf56837ff21f0ef96424e8b29 upstream.

Fix __cpuidle_set_driver() to check if any of the CPUs in the mask has
a driver different from drv already and, if so, return -EBUSY before
updating any cpuidle_drivers per-CPU pointers.

Fixes: 82467a5a885d ("cpuidle: simplify multiple driver support")
Cc: 3.11+  # 3.11+
Signed-off-by: Zhenzhong Duan 
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

cpuidle: teo: Allow tick to be stopped if PM QoS is used

2019-10-05T13:11:33+00:00

[ Upstream commit cab09f3d2d2a0a6cb3dfb678660d67a2c3764f50 ]

The TEO goveror prevents the scheduler tick from being stopped (unless
stopped already) if there is a PM QoS latency constraint for the given
CPU and the target residency of the deepest idle state matching that
constraint is below the tick boundary.

However, that is problematic if CPUs with PM QoS latency constraints
are idle for long times, because it effectively causes the tick to
run on them all the time which is wasteful.  [It is also confusing
and questionable if they are full dynticks CPUs.]

To address that issue, modify the TEO governor to carry out the
entire search for the most suitable idle state (from the target
residency perspective) even if a latency constraint is present,
to allow it to determine the expected idle duration in all cases.

Also, when using the last several measured idle duration values
to refine the idle state selection, make it compare those values
with the current expected idle duration value (instead of
comparing them with the target residency of the idle state
selected so far) which should prevent the tick from being
retained when it makes sense to stop it sometimes (especially
in the presence of PM QoS latency constraints).

Fixes: b26bf6ab716f ("cpuidle: New timer events oriented governor for tickless systems")
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

Merge branch 'pm-cpufreq'

2019-07-18T07:49:30+00:00

* 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()

PM / QOS: Rename __dev_pm_qos_read_value() and dev_pm_qos_raw_read_value()

2019-07-04T08:40:54+00:00

dev_pm_qos_read_value() will soon need to support more constraint types
(min/max frequency) and will have another argument to it, i.e. type of
the constraint. While that is fine for the existing users of
dev_pm_qos_read_value(), but not that optimal for the callers of
__dev_pm_qos_read_value() and dev_pm_qos_raw_read_value() as all the
callers of these two routines are only looking for resume latency
constraint.

Lets make these two routines care only about the resume latency
constraint and rename them to __dev_pm_qos_resume_latency() and
dev_pm_qos_raw_resume_latency().

Suggested-by: Rafael J. Wysocki 
Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55+00:00

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 
Reviewed-by: Enrico Weigelt 
Reviewed-by: Kate Stewart 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428

2019-06-05T15:37:16+00:00

Based on 1 normalized pattern(s):

  this file is released under the gplv2

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 68 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Armijn Hemel 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190114.292346262@linutronix.de
Signed-off-by: Greg Kroah-Hartman