2.3 Userspace
2.4 Ondemand
2.5 Conservative
-2.6 Interactive
3. The Governor Interface in the CPUfreq Core
default value of '20' it means that if the CPU usage needs to be below
20% between samples to have the frequency decreased.
-
-2.6 Interactive
----------------
-
-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 th highest value between that longer-term load or the
-short-term load since idle exit to determine the cpu speed to ramp to.
-
-The tuneable value for this governor are:
-
-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.
-
-go_maxspeed_load: The CPU load at which to ramp to max speed. Default
-is 85.
-
-
3. The Governor Interface in the CPUfreq Core
=============================================
projects / firefly-linux-kernel-4.4.55.git / blobdiff