diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-11 17:03:20 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-11 17:03:20 -0700 |
commit | 1fe43114ea7355ec9f336c942aaf3e74d27483a0 (patch) | |
tree | a42dfb282f2e3fb3adaa9359494081c67da66293 /Documentation | |
parent | 96973767594fe9c5d8a7e8fc594c9e565ab0374e (diff) | |
parent | 51798deaffb738ef3bdd4f544b11ce2adaff40f3 (diff) |
Merge tag 'pm-4.17-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more power management updates from Rafael Wysocki:
"These include one big-ticket item which is the rework of the idle loop
in order to prevent CPUs from spending too much time in shallow idle
states. It reduces idle power on some systems by 10% or more and may
improve performance of workloads in which the idle loop overhead
matters. This has been in the works for several weeks and it has been
tested and reviewed quite thoroughly.
Also included are changes that finalize the cpufreq cleanup moving
frequency table validation from drivers to the core, a few fixes and
cleanups of cpufreq drivers, a cpuidle documentation update and a PM
QoS core update to mark the expected switch fall-throughs in it.
Specifics:
- Rework the idle loop in order to prevent CPUs from spending too
much time in shallow idle states by making it stop the scheduler
tick before putting the CPU into an idle state only if the idle
duration predicted by the idle governor is long enough.
That required the code to be reordered to invoke the idle governor
before stopping the tick, among other things (Rafael Wysocki,
Frederic Weisbecker, Arnd Bergmann).
- Add the missing description of the residency sysfs attribute to the
cpuidle documentation (Prashanth Prakash).
- Finalize the cpufreq cleanup moving frequency table validation from
drivers to the core (Viresh Kumar).
- Fix a clock leak regression in the armada-37xx cpufreq driver
(Gregory Clement).
- Fix the initialization of the CPU performance data structures for
shared policies in the CPPC cpufreq driver (Shunyong Yang).
- Clean up the ti-cpufreq, intel_pstate and CPPC cpufreq drivers a
bit (Viresh Kumar, Rafael Wysocki).
- Mark the expected switch fall-throughs in the PM QoS core (Gustavo
Silva)"
* tag 'pm-4.17-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (23 commits)
tick-sched: avoid a maybe-uninitialized warning
cpufreq: Drop cpufreq_table_validate_and_show()
cpufreq: SCMI: Don't validate the frequency table twice
cpufreq: CPPC: Initialize shared perf capabilities of CPUs
cpufreq: armada-37xx: Fix clock leak
cpufreq: CPPC: Don't set transition_latency
cpufreq: ti-cpufreq: Use builtin_platform_driver()
cpufreq: intel_pstate: Do not include debugfs.h
PM / QoS: mark expected switch fall-throughs
cpuidle: Add definition of residency to sysfs documentation
time: hrtimer: Use timerqueue_iterate_next() to get to the next timer
nohz: Avoid duplication of code related to got_idle_tick
nohz: Gather tick_sched booleans under a common flag field
cpuidle: menu: Avoid selecting shallow states with stopped tick
cpuidle: menu: Refine idle state selection for running tick
sched: idle: Select idle state before stopping the tick
time: hrtimer: Introduce hrtimer_next_event_without()
time: tick-sched: Split tick_nohz_stop_sched_tick()
cpuidle: Return nohz hint from cpuidle_select()
jiffies: Introduce USER_TICK_USEC and redefine TICK_USEC
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/cpu-freq/core.txt | 12 | ||||
-rw-r--r-- | Documentation/cpu-freq/cpu-drivers.txt | 6 | ||||
-rw-r--r-- | Documentation/cpuidle/sysfs.txt | 6 |
3 files changed, 13 insertions, 11 deletions
diff --git a/Documentation/cpu-freq/core.txt b/Documentation/cpu-freq/core.txt index 978463a7c81e..073f128af5a7 100644 --- a/Documentation/cpu-freq/core.txt +++ b/Documentation/cpu-freq/core.txt @@ -97,12 +97,10 @@ flags - flags of the cpufreq driver ================================================================== For details about OPP, see Documentation/power/opp.txt -dev_pm_opp_init_cpufreq_table - cpufreq framework typically is initialized with - cpufreq_table_validate_and_show() which is provided with the list of - frequencies that are available for operation. This function provides - a ready to use conversion routine to translate the OPP layer's internal - information about the available frequencies into a format readily - providable to cpufreq. +dev_pm_opp_init_cpufreq_table - + This function provides a ready to use conversion routine to translate + the OPP layer's internal information about the available frequencies + into a format readily providable to cpufreq. WARNING: Do not use this function in interrupt context. @@ -112,7 +110,7 @@ dev_pm_opp_init_cpufreq_table - cpufreq framework typically is initialized with /* Do things */ r = dev_pm_opp_init_cpufreq_table(dev, &freq_table); if (!r) - cpufreq_table_validate_and_show(policy, freq_table); + policy->freq_table = freq_table; /* Do other things */ } diff --git a/Documentation/cpu-freq/cpu-drivers.txt b/Documentation/cpu-freq/cpu-drivers.txt index 61546ac578d6..6e353d00cdc6 100644 --- a/Documentation/cpu-freq/cpu-drivers.txt +++ b/Documentation/cpu-freq/cpu-drivers.txt @@ -259,10 +259,8 @@ CPUFREQ_ENTRY_INVALID. The entries don't need to be in sorted in any particular order, but if they are cpufreq core will do DVFS a bit quickly for them as search for best match is faster. -By calling cpufreq_table_validate_and_show(), the cpuinfo.min_freq and -cpuinfo.max_freq values are detected, and policy->min and policy->max -are set to the same values. This is helpful for the per-CPU -initialization stage. +The cpufreq table is verified automatically by the core if the policy contains a +valid pointer in its policy->freq_table field. cpufreq_frequency_table_verify() assures that at least one valid frequency is within policy->min and policy->max, and all other criteria diff --git a/Documentation/cpuidle/sysfs.txt b/Documentation/cpuidle/sysfs.txt index b6f44f490ed7..d1587f434e7b 100644 --- a/Documentation/cpuidle/sysfs.txt +++ b/Documentation/cpuidle/sysfs.txt @@ -40,6 +40,7 @@ total 0 -r--r--r-- 1 root root 4096 Feb 8 10:42 latency -r--r--r-- 1 root root 4096 Feb 8 10:42 name -r--r--r-- 1 root root 4096 Feb 8 10:42 power +-r--r--r-- 1 root root 4096 Feb 8 10:42 residency -r--r--r-- 1 root root 4096 Feb 8 10:42 time -r--r--r-- 1 root root 4096 Feb 8 10:42 usage @@ -50,6 +51,7 @@ total 0 -r--r--r-- 1 root root 4096 Feb 8 10:42 latency -r--r--r-- 1 root root 4096 Feb 8 10:42 name -r--r--r-- 1 root root 4096 Feb 8 10:42 power +-r--r--r-- 1 root root 4096 Feb 8 10:42 residency -r--r--r-- 1 root root 4096 Feb 8 10:42 time -r--r--r-- 1 root root 4096 Feb 8 10:42 usage @@ -60,6 +62,7 @@ total 0 -r--r--r-- 1 root root 4096 Feb 8 10:42 latency -r--r--r-- 1 root root 4096 Feb 8 10:42 name -r--r--r-- 1 root root 4096 Feb 8 10:42 power +-r--r--r-- 1 root root 4096 Feb 8 10:42 residency -r--r--r-- 1 root root 4096 Feb 8 10:42 time -r--r--r-- 1 root root 4096 Feb 8 10:42 usage @@ -70,6 +73,7 @@ total 0 -r--r--r-- 1 root root 4096 Feb 8 10:42 latency -r--r--r-- 1 root root 4096 Feb 8 10:42 name -r--r--r-- 1 root root 4096 Feb 8 10:42 power +-r--r--r-- 1 root root 4096 Feb 8 10:42 residency -r--r--r-- 1 root root 4096 Feb 8 10:42 time -r--r--r-- 1 root root 4096 Feb 8 10:42 usage -------------------------------------------------------------------------------- @@ -78,6 +82,8 @@ total 0 * desc : Small description about the idle state (string) * disable : Option to disable this idle state (bool) -> see note below * latency : Latency to exit out of this idle state (in microseconds) +* residency : Time after which a state becomes more effecient than any + shallower state (in microseconds) * name : Name of the idle state (string) * power : Power consumed while in this idle state (in milliwatts) * time : Total time spent in this idle state (in microseconds) |