Lines Matching refs:to
16 Clock scaling allows you to change the clock speed of the CPUs on the
17 fly. This is a nice method to save battery power, because the lower
40 cpu frequency scaling algorithms only offer the CPU to be set to one
41 frequency. In order to offer dynamic frequency scaling, the cpufreq
42 core must be able to tell these drivers of a "target frequency". So
43 these specific drivers will be transformed to offer a "->target/target_index"
47 How to decide what frequency within the CPUfreq policy should be used?
50 set the frequency statically to the lowest or highest frequency,
54 around. Using such a generic interface as cpufreq offers to scaling
60 CPU can be set to switch independently | CPU can only be set
61 within specific "limits" | to specific frequencies
65 and CPUfreq governor to be used
70 / what target_freq to set within
76 "policy" is set. to target_freq is set.
87 The CPUfreq governor "performance" sets the CPU statically to the
95 The CPUfreq governor "powersave" sets the CPU statically to the
104 program running with UID "root", to set the CPU to a specific frequency
113 current usage. To do this the CPU must have the capability to
118 want the kernel to look at the CPU usage and to make decisions on
119 what to do about the frequency. Typically this is set to values of
144 of 'sampling_rate' needs to be for the kernel to make a decision on
146 to its default value of '95' it means that between the checking
147 intervals the CPU needs to be on average more than 95% in use to then
148 decide that the CPU frequency needs to be increased.
151 set to '0' (its default), all processes are counted towards the
152 'cpu utilisation' value. When set to '1', the processes that are
156 takes to complete as you can 'nice' it and prevent it from taking part
157 in the deciding process of whether to increase your CPU frequency.
160 kernel makes a decision on when to decrease the frequency while running
161 at top speed. When set to 1 (the default) decisions to reevaluate load
163 when set to greater than 1 (e.g. 100) it acts as a multiplier for the
165 speed due to high load. This improves performance by reducing the overhead
170 powersave_bias: this parameter takes a value between 0 to 1000. It
172 will be shaved off of the target. For example, when set to 100 -- 10%,
174 1000 MHz - (10% of 1000 MHz) = 900 MHz instead. This is set to 0
181 Processors and above) value between 0 to 100% that tells software how
186 higher the frequency. When the driver is loaded, this is set to 400
198 rather than jumping to max speed the moment there is any load on the
206 value to anywhere between 0 and 100 where '0' will effectively lock your
208 it behave identically to the "ondemand" governor.
211 governor but for the opposite direction. For example when set to its
212 default value of '20' it means that if the CPU usage needs to be below
213 20% between samples to have the frequency decreased.
217 a decision on when to decrease the frequency while running in any
225 "cpufreq_register_governor". The struct cpufreq_governor, which has to
226 be passed to that function, must contain the following values:
233 The governor->governor callback is called with the current (or to-be-set)
241 CPUFREQ_GOV_LIMITS: The limits for CPU policy->cpu have changed to
245 cpufreq_governor_l(unsigned int cpu, unsigned int event) call to the
246 CPUfreq core to ensure proper locking.
262 still is in a direct code path of a call to governor->governor, the
264 no need to lock it again (in fact, this would cause a deadlock). So
267 every second), use cpufreq_driver_target to lock the cpufreq per-CPU
268 lock before the command is passed to the cpufreq processor driver.