130 lines
4.1 KiB
Plaintext
130 lines
4.1 KiB
Plaintext
config CPU_FREQ
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bool "CPU Frequency scaling"
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help
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CPU Frequency scaling allows you to change the clock speed of
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CPUs on the fly. This is a nice method to save power, because
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the lower the CPU clock speed, the less power the CPU consumes.
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Note that this driver doesn't automatically change the CPU
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clock speed, you need to either enable a dynamic cpufreq governor
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(see below) after boot, or use a userspace tool.
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For details, take a look at <file:Documentation/cpu-freq>.
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If in doubt, say N.
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config CPU_FREQ_DEBUG
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bool "Enable CPUfreq debugging"
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depends on CPU_FREQ
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help
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Say Y here to enable CPUfreq subsystem (including drivers)
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debugging. You will need to activate it via the kernel
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command line by passing
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cpufreq.debug=<value>
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To get <value>, add
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1 to activate CPUfreq core debugging,
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2 to activate CPUfreq drivers debugging, and
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4 to activate CPUfreq governor debugging
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config CPU_FREQ_PROC_INTF
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tristate "/proc/cpufreq interface (deprecated)"
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depends on CPU_FREQ && PROC_FS
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help
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This enables the /proc/cpufreq interface for controlling
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CPUFreq. Please note that it is recommended to use the sysfs
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interface instead (which is built automatically).
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For details, take a look at <file:Documentation/cpu-freq/>.
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If in doubt, say N.
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choice
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prompt "Default CPUFreq governor"
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depends on CPU_FREQ
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default CPU_FREQ_DEFAULT_GOV_PERFORMANCE if !CPU_FREQ_SA1100 && !CPU_FREQ_SA1110
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default CPU_FREQ_DEFAULT_GOV_USERSPACE if CPU_FREQ_SA1100 || CPU_FREQ_SA1110
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help
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This option sets which CPUFreq governor shall be loaded at
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startup. If in doubt, select 'performance'.
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config CPU_FREQ_DEFAULT_GOV_PERFORMANCE
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bool "performance"
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select CPU_FREQ_GOV_PERFORMANCE
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help
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Use the CPUFreq governor 'performance' as default. This sets
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the frequency statically to the highest frequency supported by
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the CPU.
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config CPU_FREQ_DEFAULT_GOV_USERSPACE
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bool "userspace"
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select CPU_FREQ_GOV_USERSPACE
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help
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Use the CPUFreq governor 'userspace' as default. This allows
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you to set the CPU frequency manually or when an userspace
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program shall be able to set the CPU dynamically without having
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to enable the userspace governor manually.
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endchoice
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config CPU_FREQ_GOV_PERFORMANCE
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tristate "'performance' governor"
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depends on CPU_FREQ
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help
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This cpufreq governor sets the frequency statically to the
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highest available CPU frequency.
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If in doubt, say Y.
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config CPU_FREQ_GOV_POWERSAVE
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tristate "'powersave' governor"
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depends on CPU_FREQ
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help
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This cpufreq governor sets the frequency statically to the
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lowest available CPU frequency.
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If in doubt, say Y.
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config CPU_FREQ_GOV_USERSPACE
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tristate "'userspace' governor for userspace frequency scaling"
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depends on CPU_FREQ
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help
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Enable this cpufreq governor when you either want to set the
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CPU frequency manually or when an userspace program shall
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be able to set the CPU dynamically, like on LART
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<http://www.lart.tudelft.nl/>
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For details, take a look at <file:Documentation/cpu-freq/>.
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If in doubt, say Y.
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config CPU_FREQ_24_API
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bool "/proc/sys/cpu/ interface (2.4. / OLD)"
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depends on CPU_FREQ_GOV_USERSPACE
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depends on SYSCTL
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help
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This enables the /proc/sys/cpu/ sysctl interface for controlling
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the CPUFreq,"userspace" governor. This is the same interface
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as known from the 2.4.-kernel patches for CPUFreq, and offers
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the same functionality as long as "userspace" is the
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selected governor for the specified CPU.
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For details, take a look at <file:Documentation/cpu-freq/>.
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If in doubt, say N.
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config CPU_FREQ_GOV_ONDEMAND
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tristate "'ondemand' cpufreq policy governor"
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depends on CPU_FREQ
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help
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'ondemand' - This driver adds a dynamic cpufreq policy governor.
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The governor does a periodic polling and
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changes frequency based on the CPU utilization.
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The support for this governor depends on CPU capability to
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do fast frequency switching (i.e, very low latency frequency
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transitions).
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For details, take a look at linux/Documentation/cpu-freq.
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If in doubt, say N.
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