cpufreq: interactive: allow arbitrary speed / target load mappings
Accept a string of target loads and speeds at which to apply the
target loads, per the documentation update in this patch. For example,
"85 1000000:90 1700000:99" targets CPU load 85% below speed 1GHz, 90%
at or above 1GHz, until 1.7GHz and above, at which load 99% is targeted.
Attempt to avoid oscillations by evaluating the current speed
weighted by current load against each new choice of speed, choosing a
higher speed if the current load requires a higher speed.
Change-Id: Ie3300206047c84eca5a26b0b63ea512e5207550e
Signed-off-by: Todd Poynor <toddpoynor@google.com>
diff --git a/Documentation/cpu-freq/governors.txt b/Documentation/cpu-freq/governors.txt
index 509b179..b15f6d2 100644
--- a/Documentation/cpu-freq/governors.txt
+++ b/Documentation/cpu-freq/governors.txt
@@ -244,6 +244,23 @@
The tuneable values for this governor are:
+target_loads: CPU load values used to adjust speed to influence the
+current CPU load toward that value. In general, the lower the target
+load, the more often the governor will raise CPU speeds to bring load
+below the target. The format is a single target load, optionally
+followed by pairs of CPU speeds and CPU loads to target at or above
+those speeds. Colons can be used between the speeds and associated
+target loads for readability. For example:
+
+ 85 1000000:90 1700000:99
+
+targets CPU load 85% below speed 1GHz, 90% at or above 1GHz, until
+1.7GHz and above, at which load 99% is targeted. If speeds are
+specified these must appear in ascending order. Higher target load
+values are typically specified for higher speeds, that is, target load
+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