| Kconfig (5a84d159061d914c8dd4aa372ac6e9529c2be453) | Kconfig (9101be532a3c60c7e8773868395e3b75259d84c3) |
|---|---|
| 1config CPU_FREQ 2 bool "CPU Frequency scaling" 3 help 4 CPU Frequency scaling allows you to change the clock speed of 5 CPUs on the fly. This is a nice method to save power, because 6 the lower the CPU clock speed, the less power the CPU consumes. 7 8 Note that this driver doesn't automatically change the CPU 9 clock speed, you need to either enable a dynamic cpufreq governor 10 (see below) after boot, or use a userspace tool. 11 | 1config CPU_FREQ 2 bool "CPU Frequency scaling" 3 help 4 CPU Frequency scaling allows you to change the clock speed of 5 CPUs on the fly. This is a nice method to save power, because 6 the lower the CPU clock speed, the less power the CPU consumes. 7 8 Note that this driver doesn't automatically change the CPU 9 clock speed, you need to either enable a dynamic cpufreq governor 10 (see below) after boot, or use a userspace tool. 11 |
| 12 To compile this driver as a module, choose M here: the 13 module will be called cpufreq. 14 |
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| 12 For details, take a look at <file:Documentation/cpu-freq>. 13 14 If in doubt, say N. 15 16if CPU_FREQ 17 18config CPU_FREQ_TABLE | 15 For details, take a look at <file:Documentation/cpu-freq>. 16 17 If in doubt, say N. 18 19if CPU_FREQ 20 21config CPU_FREQ_TABLE |
| 19 tristate | 22 tristate |
| 20 21config CPU_FREQ_DEBUG 22 bool "Enable CPUfreq debugging" 23 help 24 Say Y here to enable CPUfreq subsystem (including drivers) 25 debugging. You will need to activate it via the kernel 26 command line by passing 27 cpufreq.debug=<value> 28 29 To get <value>, add 30 1 to activate CPUfreq core debugging, 31 2 to activate CPUfreq drivers debugging, and 32 4 to activate CPUfreq governor debugging 33 34config CPU_FREQ_STAT | 23 24config CPU_FREQ_DEBUG 25 bool "Enable CPUfreq debugging" 26 help 27 Say Y here to enable CPUfreq subsystem (including drivers) 28 debugging. You will need to activate it via the kernel 29 command line by passing 30 cpufreq.debug=<value> 31 32 To get <value>, add 33 1 to activate CPUfreq core debugging, 34 2 to activate CPUfreq drivers debugging, and 35 4 to activate CPUfreq governor debugging 36 37config CPU_FREQ_STAT |
| 35 tristate "CPU frequency translation statistics" 36 select CPU_FREQ_TABLE 37 default y 38 help 39 This driver exports CPU frequency statistics information through sysfs 40 file system | 38 tristate "CPU frequency translation statistics" 39 select CPU_FREQ_TABLE 40 default y 41 help 42 This driver exports CPU frequency statistics information through sysfs 43 file system. |
| 41 | 44 |
| 45 To compile this driver as a module, choose M here: the 46 module will be called cpufreq_stats. 47 48 If in doubt, say N. 49 |
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| 42config CPU_FREQ_STAT_DETAILS | 50config CPU_FREQ_STAT_DETAILS |
| 43 bool "CPU frequency translation statistics details" 44 depends on CPU_FREQ_STAT 45 help 46 This will show detail CPU frequency translation table in sysfs file 47 system | 51 bool "CPU frequency translation statistics details" 52 depends on CPU_FREQ_STAT 53 help 54 This will show detail CPU frequency translation table in sysfs file 55 system. |
| 48 | 56 |
| 57 If in doubt, say N. 58 |
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| 49# Note that it is not currently possible to set the other governors (such as ondemand) 50# as the default, since if they fail to initialise, cpufreq will be 51# left in an undefined state. 52 53choice 54 prompt "Default CPUFreq governor" 55 default CPU_FREQ_DEFAULT_GOV_USERSPACE if CPU_FREQ_SA1100 || CPU_FREQ_SA1110 56 default CPU_FREQ_DEFAULT_GOV_PERFORMANCE --- 16 unchanged lines hidden (view full) --- 73 Use the CPUFreq governor 'userspace' as default. This allows 74 you to set the CPU frequency manually or when an userspace 75 program shall be able to set the CPU dynamically without having 76 to enable the userspace governor manually. 77 78endchoice 79 80config CPU_FREQ_GOV_PERFORMANCE | 59# Note that it is not currently possible to set the other governors (such as ondemand) 60# as the default, since if they fail to initialise, cpufreq will be 61# left in an undefined state. 62 63choice 64 prompt "Default CPUFreq governor" 65 default CPU_FREQ_DEFAULT_GOV_USERSPACE if CPU_FREQ_SA1100 || CPU_FREQ_SA1110 66 default CPU_FREQ_DEFAULT_GOV_PERFORMANCE --- 16 unchanged lines hidden (view full) --- 83 Use the CPUFreq governor 'userspace' as default. This allows 84 you to set the CPU frequency manually or when an userspace 85 program shall be able to set the CPU dynamically without having 86 to enable the userspace governor manually. 87 88endchoice 89 90config CPU_FREQ_GOV_PERFORMANCE |
| 81 tristate "'performance' governor" 82 help | 91 tristate "'performance' governor" 92 help |
| 83 This cpufreq governor sets the frequency statically to the 84 highest available CPU frequency. 85 | 93 This cpufreq governor sets the frequency statically to the 94 highest available CPU frequency. 95 |
| 96 To compile this driver as a module, choose M here: the 97 module will be called cpufreq_performance. 98 |
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| 86 If in doubt, say Y. 87 88config CPU_FREQ_GOV_POWERSAVE | 99 If in doubt, say Y. 100 101config CPU_FREQ_GOV_POWERSAVE |
| 89 tristate "'powersave' governor" 90 help | 102 tristate "'powersave' governor" 103 help |
| 91 This cpufreq governor sets the frequency statically to the 92 lowest available CPU frequency. 93 | 104 This cpufreq governor sets the frequency statically to the 105 lowest available CPU frequency. 106 |
| 107 To compile this driver as a module, choose M here: the 108 module will be called cpufreq_powersave. 109 |
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| 94 If in doubt, say Y. 95 96config CPU_FREQ_GOV_USERSPACE | 110 If in doubt, say Y. 111 112config CPU_FREQ_GOV_USERSPACE |
| 97 tristate "'userspace' governor for userspace frequency scaling" 98 help | 113 tristate "'userspace' governor for userspace frequency scaling" 114 help |
| 99 Enable this cpufreq governor when you either want to set the 100 CPU frequency manually or when an userspace program shall 101 be able to set the CPU dynamically, like on LART 102 <http://www.lartmaker.nl/>. 103 | 115 Enable this cpufreq governor when you either want to set the 116 CPU frequency manually or when an userspace program shall 117 be able to set the CPU dynamically, like on LART 118 <http://www.lartmaker.nl/>. 119 |
| 120 To compile this driver as a module, choose M here: the 121 module will be called cpufreq_userspace. 122 |
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| 104 For details, take a look at <file:Documentation/cpu-freq/>. 105 106 If in doubt, say Y. 107 108config CPU_FREQ_GOV_ONDEMAND 109 tristate "'ondemand' cpufreq policy governor" 110 select CPU_FREQ_TABLE 111 help 112 'ondemand' - This driver adds a dynamic cpufreq policy governor. 113 The governor does a periodic polling and 114 changes frequency based on the CPU utilization. 115 The support for this governor depends on CPU capability to 116 do fast frequency switching (i.e, very low latency frequency 117 transitions). 118 | 123 For details, take a look at <file:Documentation/cpu-freq/>. 124 125 If in doubt, say Y. 126 127config CPU_FREQ_GOV_ONDEMAND 128 tristate "'ondemand' cpufreq policy governor" 129 select CPU_FREQ_TABLE 130 help 131 'ondemand' - This driver adds a dynamic cpufreq policy governor. 132 The governor does a periodic polling and 133 changes frequency based on the CPU utilization. 134 The support for this governor depends on CPU capability to 135 do fast frequency switching (i.e, very low latency frequency 136 transitions). 137 |
| 138 To compile this driver as a module, choose M here: the 139 module will be called cpufreq_ondemand. 140 |
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| 119 For details, take a look at linux/Documentation/cpu-freq. 120 121 If in doubt, say N. 122 123config CPU_FREQ_GOV_CONSERVATIVE 124 tristate "'conservative' cpufreq governor" 125 depends on CPU_FREQ 126 help --- 4 unchanged lines hidden (view full) --- 131 rather than jumping to 100% when speed is required. 132 133 If you have a desktop machine then you should really be considering 134 the 'ondemand' governor instead, however if you are using a laptop, 135 PDA or even an AMD64 based computer (due to the unacceptable 136 step-by-step latency issues between the minimum and maximum frequency 137 transitions in the CPU) you will probably want to use this governor. 138 | 141 For details, take a look at linux/Documentation/cpu-freq. 142 143 If in doubt, say N. 144 145config CPU_FREQ_GOV_CONSERVATIVE 146 tristate "'conservative' cpufreq governor" 147 depends on CPU_FREQ 148 help --- 4 unchanged lines hidden (view full) --- 153 rather than jumping to 100% when speed is required. 154 155 If you have a desktop machine then you should really be considering 156 the 'ondemand' governor instead, however if you are using a laptop, 157 PDA or even an AMD64 based computer (due to the unacceptable 158 step-by-step latency issues between the minimum and maximum frequency 159 transitions in the CPU) you will probably want to use this governor. 160 |
| 161 To compile this driver as a module, choose M here: the 162 module will be called cpufreq_conservative. 163 |
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| 139 For details, take a look at linux/Documentation/cpu-freq. 140 141 If in doubt, say N. 142 143endif # CPU_FREQ | 164 For details, take a look at linux/Documentation/cpu-freq. 165 166 If in doubt, say N. 167 168endif # CPU_FREQ |