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Diffstat (limited to 'Documentation/cpu-freq')
-rw-r--r-- | Documentation/cpu-freq/governors.txt | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/Documentation/cpu-freq/governors.txt b/Documentation/cpu-freq/governors.txt index 4dfed30b7fda..66f9cc310686 100644 --- a/Documentation/cpu-freq/governors.txt +++ b/Documentation/cpu-freq/governors.txt | |||
@@ -167,6 +167,27 @@ of load evaluation and helping the CPU stay at its top speed when truly | |||
167 | busy, rather than shifting back and forth in speed. This tunable has no | 167 | busy, rather than shifting back and forth in speed. This tunable has no |
168 | effect on behavior at lower speeds/lower CPU loads. | 168 | effect on behavior at lower speeds/lower CPU loads. |
169 | 169 | ||
170 | powersave_bias: this parameter takes a value between 0 to 1000. It | ||
171 | defines the percentage (times 10) value of the target frequency that | ||
172 | will be shaved off of the target. For example, when set to 100 -- 10%, | ||
173 | when ondemand governor would have targeted 1000 MHz, it will target | ||
174 | 1000 MHz - (10% of 1000 MHz) = 900 MHz instead. This is set to 0 | ||
175 | (disabled) by default. | ||
176 | When AMD frequency sensitivity powersave bias driver -- | ||
177 | drivers/cpufreq/amd_freq_sensitivity.c is loaded, this parameter | ||
178 | defines the workload frequency sensitivity threshold in which a lower | ||
179 | frequency is chosen instead of ondemand governor's original target. | ||
180 | The frequency sensitivity is a hardware reported (on AMD Family 16h | ||
181 | Processors and above) value between 0 to 100% that tells software how | ||
182 | the performance of the workload running on a CPU will change when | ||
183 | frequency changes. A workload with sensitivity of 0% (memory/IO-bound) | ||
184 | will not perform any better on higher core frequency, whereas a | ||
185 | workload with sensitivity of 100% (CPU-bound) will perform better | ||
186 | higher the frequency. When the driver is loaded, this is set to 400 | ||
187 | by default -- for CPUs running workloads with sensitivity value below | ||
188 | 40%, a lower frequency is chosen. Unloading the driver or writing 0 | ||
189 | will disable this feature. | ||
190 | |||
170 | 191 | ||
171 | 2.5 Conservative | 192 | 2.5 Conservative |
172 | ---------------- | 193 | ---------------- |