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[PATCH 37/70] cpufreq: interactive: default go_hispeed_load 99%, doc updates

From Bálint Czobor <czoborbalint@gmail.com>
Newsgroups linux.kernel
Subject [PATCH 37/70] cpufreq: interactive: default go_hispeed_load 99%, doc updates
Date 2015-10-27 18:40 +0100
Message-ID <qogo3-84h-77@gated-at.bofh.it> (permalink)
References <qogo1-84h-5@gated-at.bofh.it>
Organization linux.* mail to news gateway

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From: Todd Poynor <toddpoynor@google.com>

Update default go_hispeed_load from 85% to 99%.  Recent changes to the
governor now use a default target_load of 90%.  go_hispeed_load should
not be lower than the target load for hispeed_freq, which could lead
to oscillating speed decisions.  Other recent changes reduce the need
to dampen speed jumps on load spikes, while input event boosts from
userspace are the preferred method for anticipating load spikes with
UI impacts.

General update to the documentation to reflect recent changes.

Change-Id: I1b92f3091f42c04b10503cd1169a943b5dfd6faf
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Bálint Czobor <czoborbalint@gmail.com>
---
 Documentation/cpu-freq/governors.txt  |   64 ++++++++++++++++-----------------
 drivers/cpufreq/cpufreq_interactive.c |    2 +-
 2 files changed, 33 insertions(+), 33 deletions(-)

diff --git a/Documentation/cpu-freq/governors.txt b/Documentation/cpu-freq/governors.txt
index b15f6d2..4d8ae34 100644
--- a/Documentation/cpu-freq/governors.txt
+++ b/Documentation/cpu-freq/governors.txt
@@ -224,23 +224,8 @@ sampling rate.
 
 The CPUfreq governor "interactive" is designed for latency-sensitive,
 interactive workloads. This governor sets the CPU speed depending on
-usage, similar to "ondemand" and "conservative" governors.  However,
-the governor is more aggressive about scaling the CPU speed up in
-response to CPU-intensive activity.
-
-Sampling the CPU load every X ms can lead to under-powering the CPU
-for X ms, leading to dropped frames, stuttering UI, etc.  Instead of
-sampling the cpu at a specified rate, the interactive governor will
-check whether to scale the cpu frequency up soon after coming out of
-idle.  When the cpu comes out of idle, a timer is configured to fire
-within 1-2 ticks.  If the cpu is very busy between exiting idle and
-when the timer fires then we assume the cpu is underpowered and ramp
-to MAX speed.
-
-If the cpu was not sufficiently busy to immediately ramp to MAX speed,
-then governor evaluates the cpu load since the last speed adjustment,
-choosing the highest value between that longer-term load or the
-short-term load since idle exit to determine the cpu speed to ramp to.
+usage, similar to "ondemand" and "conservative" governors, but with a
+different set of configurable behaviors.
 
 The tuneable values for this governor are:
 
@@ -262,36 +247,51 @@ values also usually appear in an ascending order. The default is
 target load 90% for all speeds.
 
 min_sample_time: The minimum amount of time to spend at the current
-frequency before ramping down. This is to ensure that the governor has
-seen enough historic cpu load data to determine the appropriate
-workload.  Default is 80000 uS.
+frequency before ramping down. Default is 80000 uS.
 
 hispeed_freq: An intermediate "hi speed" at which to initially ramp
 when CPU load hits the value specified in go_hispeed_load.  If load
 stays high for the amount of time specified in above_hispeed_delay,
-then speed may be bumped higher.  Default is maximum speed.
+then speed may be bumped higher.  Default is the maximum speed
+allowed by the policy at governor initialization time.
 
-go_hispeed_load: The CPU load at which to ramp to the intermediate "hi
-speed".  Default is 85%.
+go_hispeed_load: The CPU load at which to ramp to hispeed_freq.
+Default is 99%.
 
-above_hispeed_delay: Once speed is set to hispeed_freq, wait for this
-long before bumping speed higher in response to continued high load.
+above_hispeed_delay: When speed is at or above hispeed_freq, wait for
+this long before raising speed in response to continued high load.
 Default is 20000 uS.
 
-timer_rate: Sample rate for reevaluating cpu load when the system is
-not idle.  Default is 20000 uS.
-
-input_boost: If non-zero, boost speed of all CPUs to hispeed_freq on
-touchscreen activity.  Default is 0.
+timer_rate: Sample rate for reevaluating CPU load when the CPU is not
+idle.  A deferrable timer is used, such that the CPU will not be woken
+from idle to service this timer until something else needs to run.
+(The maximum time to allow deferring this timer when not running at
+minimum speed is configurable via timer_slack.)  Default is 20000 uS.
+
+timer_slack: Maximum additional time to defer handling the governor
+sampling timer beyond timer_rate when running at speeds above the
+minimum.  For platforms that consume additional power at idle when
+CPUs are running at speeds greater than minimum, this places an upper
+bound on how long the timer will be deferred prior to re-evaluating
+load and dropping speed.  For example, if timer_rate is 20000uS and
+timer_slack is 10000uS then timers will be deferred for up to 30msec
+when not at lowest speed.  A value of -1 means defer timers
+indefinitely at all speeds.  Default is 80000 uS.
 
 boost: If non-zero, immediately boost speed of all CPUs to at least
 hispeed_freq until zero is written to this attribute.  If zero, allow
 CPU speeds to drop below hispeed_freq according to load as usual.
+Default is zero.
 
-boostpulse: Immediately boost speed of all CPUs to hispeed_freq for
-min_sample_time, after which speeds are allowed to drop below
+boostpulse: On each write, immediately boost speed of all CPUs to
+hispeed_freq for at least the period of time specified by
+boostpulse_duration, after which speeds are allowed to drop below
 hispeed_freq according to load as usual.
 
+boostpulse_duration: Length of time to hold CPU speed at hispeed_freq
+on a write to boostpulse, before allowing speed to drop according to
+load as usual.  Default is 80000 uS.
+
 
 3. The Governor Interface in the CPUfreq Core
 =============================================
diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cpufreq_interactive.c
index d22d162..fdc2a47 100644
--- a/drivers/cpufreq/cpufreq_interactive.c
+++ b/drivers/cpufreq/cpufreq_interactive.c
@@ -66,7 +66,7 @@ static spinlock_t speedchange_cpumask_lock;
 static unsigned int hispeed_freq;
 
 /* Go to hi speed when CPU load at or above this value. */
-#define DEFAULT_GO_HISPEED_LOAD 85
+#define DEFAULT_GO_HISPEED_LOAD 99
 static unsigned long go_hispeed_load;
 
 /* Target load.  Lower values result in higher CPU speeds. */
-- 
1.7.9.5

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Thread

[PATCH 01/70] cpufreq: interactive: New 'interactive' governor Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 57/70] cpufreq: interactive: fix compiling warnings Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 56/70] cpufreq: interactive: delete timers for GOV_START Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 41/70] cpufreq: interactive: fix race on governor start/stop Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 32/70] cpufreq: interactive: specify duration of CPU speed boost pulse Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 43/70] cpufreq: interactive: add io_is_busy interface Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 39/70] cpufreq: interactive: don't handle transition notification if not enabled Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 51/70] cpufreq: interactive: resched timer if max freq raised Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 09/70] cpufreq: interactive: Separate speed target revalidate time and initial set time Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 60/70] cpufreq: interactive: hold reference on global cpufreq kobject if needed Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 24/70] cpufreq: interactive: use deferrable timer by default Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 61/70] cpufreq: interactive: restructure CPUFREQ_GOV_LIMITS Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 27/70] cpufreq: interactive: change speed according to current speed and target load Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 07/70] cpufreq: interactive: adjust code and documentation to match Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 29/70] cpufreq: interactive: allow arbitrary speed / target load mappings Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 48/70] cpufreq: interactive: reduce chance of zero time delta on load eval Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 64/70] cpufreq: interactive: prevents the frequency to directly raise above the hispeed_freq from a lower frequency. Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 65/70] cpufreq: interactive: make common_tunables static Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 69/70] cpufreq: interactive: Don't set floor_validate_time during boost Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 37/70] cpufreq: interactive: default go_hispeed_load 99%, doc updates Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 58/70] cpufreq: interactive: fix NULL pointer dereference at sysfs ops Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 66/70] cpufreq: interactive: Fix compile errors in accordance with changes from 3.14 to 3.18 Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 17/70] cpufreq: interactive: take idle notifications only when active Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 35/70] cpufreq: interactive: fix racy timer stopping Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 67/70] cpufreq: interactive: Put global cpufreq kobject on failure Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 70/70] cpufreq: interactive: Round up timer_rate to match jiffy Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 20/70] cpufreq: interactive: remove input_boost handling Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 12/70] cpufreq: interactive: Add sysfs boost interface for hints from userspace Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 22/70] cpufreq: interactive: run at fraction of hispeed_freq when load is low Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 68/70] subsystem: CPU FREQUENCY DRIVERS- Set cpu_load calculation on current frequency Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 13/70] cpufreq: interactive: set floor for boosted speed Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 55/70] cpufreq: Interactive: Implement per policy instances of governor Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 52/70] cpufreq: interactive: fix show_target_loads and show_above_hispeed_delay Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 10/70] cpufreq: interactive: Boost frequency on touchscreen input Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:40 +0100
  [PATCH 62/70] cpufreq: interactive: turn boost_pulse off on boost off Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 59/70] cpufreq: interactive: Use generic get_cpu_idle_time() from cpufreq.c Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 54/70] cpufreq: interactive: Move definition of cpufreq_gov_interactive downwards Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 53/70] cpufreq: interactive: Remove unnecessary cpu_online() check Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 25/70] cpufreq: interactive: kick timer on idle exit past expiry Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 47/70] cpufreq: interactive: handle errors from cpufreq_frequency_table_target Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 63/70] cpufreq: interactive: remove compilation error from commit 49cc72365fb7ee87762a7ccc6a32ef68627216c5 Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 44/70] cpufreq: interactive: fix crash on error paths in get_tokenized_data Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 50/70] cpufreq: interactive: fix race on cpufreq TRANSITION notifier Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 49/70] cpufreq: interactive: avoid underflow on active time calculation Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 45/70] cpufreq: interactive: base above_hispeed_delay on target freq, not current Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 46/70] cpufreq: interactive: fix uninitialized spinlock Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 18:50 +0100
  [PATCH 34/70] cpufreq: interactive: fix boosting logic Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 38/70] cpufreq: interactive: init default values at compile time Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 16/70] cpufreq: interactive: restart above_hispeed_delay at each hispeed load Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 28/70] cpufreq: interactive: apply above_hispeed_delay to each step above hispeed Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 23/70] cpufreq: interactive: pin timers to associated CPU Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 18/70] cpufreq: interactive: keep freezer happy when not current governor Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 21/70] cpufreq: interactive: always limit initial speed bump to hispeed Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 36/70] cpufreq: interactive: fix race on timer restart on governor start Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 19/70] cpufreq: interactive: handle speed up and down in the realtime task Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 42/70] cpufreq: interactive: allow arbitrary speed / delay mappings Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 26/70] cpufreq: interactive: trace actual speed in target speed decisions Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 30/70] cpufreq: interactive: remove load since last speed change Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 40/70] cpufreq: interactive: fix deadlock on spinlock in timer Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 33/70] cpufreq: interactive: add timer slack to limit idle at speed > min Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 31/70] cpufreq: interactive: adjust load for changes in speed Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:00 +0100
  [PATCH 04/70] cpufreq: interactive: set at least hispeed when above hispeed load Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:10 +0100
  [PATCH 02/70] cpufreq interactive governor: event tracing Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:10 +0100
  [PATCH 11/70] cpufreq: interactive: remove unused target_validate_time_in_idle Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:10 +0100
  [PATCH 05/70] cpufreq: interactive: don't drop speed if recently at higher load Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:10 +0100
  [PATCH 06/70] cpufreq: interactive: configurable delay before raising above hispeed Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:10 +0100
  [PATCH 08/70] cpufreq: interactive: base hispeed bump on target freq, not actual Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:10 +0100
  [PATCH 15/70] cpufreq-interactive: Compile fixup Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:10 +0100
  [PATCH 14/70] cpufreq: interactive: add boost pulse interface Bálint Czobor <czoborbalint@gmail.com> - 2015-10-27 19:10 +0100
  Re: [PATCH 01/70] cpufreq: interactive: New 'interactive' governor "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2015-10-28 01:40 +0100
    Re: [PATCH 01/70] cpufreq: interactive: New 'interactive' governor Viresh Kumar <viresh.kumar@linaro.org> - 2015-10-28 04:10 +0100
      Re: [PATCH 01/70] cpufreq: interactive: New 'interactive' governor Viresh Kumar <viresh.kumar@linaro.org> - 2015-10-29 02:50 +0100

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