mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-19 02:04:19 +08:00
30d221db44
Allow use of the powersave cpufreq governor as the default one for EMBEDDED configs. Signed-off-by: Alessandro Guido <alessandro.guido@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Jones <davej@redhat.com>
194 lines
6.2 KiB
Plaintext
194 lines
6.2 KiB
Plaintext
config CPU_FREQ
|
|
bool "CPU Frequency scaling"
|
|
help
|
|
CPU Frequency scaling allows you to change the clock speed of
|
|
CPUs on the fly. This is a nice method to save power, because
|
|
the lower the CPU clock speed, the less power the CPU consumes.
|
|
|
|
Note that this driver doesn't automatically change the CPU
|
|
clock speed, you need to either enable a dynamic cpufreq governor
|
|
(see below) after boot, or use a userspace tool.
|
|
|
|
For details, take a look at <file:Documentation/cpu-freq>.
|
|
|
|
If in doubt, say N.
|
|
|
|
if CPU_FREQ
|
|
|
|
config CPU_FREQ_TABLE
|
|
tristate
|
|
|
|
config CPU_FREQ_DEBUG
|
|
bool "Enable CPUfreq debugging"
|
|
help
|
|
Say Y here to enable CPUfreq subsystem (including drivers)
|
|
debugging. You will need to activate it via the kernel
|
|
command line by passing
|
|
cpufreq.debug=<value>
|
|
|
|
To get <value>, add
|
|
1 to activate CPUfreq core debugging,
|
|
2 to activate CPUfreq drivers debugging, and
|
|
4 to activate CPUfreq governor debugging
|
|
|
|
config CPU_FREQ_STAT
|
|
tristate "CPU frequency translation statistics"
|
|
select CPU_FREQ_TABLE
|
|
default y
|
|
help
|
|
This driver exports CPU frequency statistics information through sysfs
|
|
file system.
|
|
|
|
To compile this driver as a module, choose M here: the
|
|
module will be called cpufreq_stats.
|
|
|
|
If in doubt, say N.
|
|
|
|
config CPU_FREQ_STAT_DETAILS
|
|
bool "CPU frequency translation statistics details"
|
|
depends on CPU_FREQ_STAT
|
|
help
|
|
This will show detail CPU frequency translation table in sysfs file
|
|
system.
|
|
|
|
If in doubt, say N.
|
|
|
|
choice
|
|
prompt "Default CPUFreq governor"
|
|
default CPU_FREQ_DEFAULT_GOV_USERSPACE if CPU_FREQ_SA1100 || CPU_FREQ_SA1110
|
|
default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
|
|
help
|
|
This option sets which CPUFreq governor shall be loaded at
|
|
startup. If in doubt, select 'performance'.
|
|
|
|
config CPU_FREQ_DEFAULT_GOV_PERFORMANCE
|
|
bool "performance"
|
|
select CPU_FREQ_GOV_PERFORMANCE
|
|
help
|
|
Use the CPUFreq governor 'performance' as default. This sets
|
|
the frequency statically to the highest frequency supported by
|
|
the CPU.
|
|
|
|
config CPU_FREQ_DEFAULT_GOV_POWERSAVE
|
|
bool "powersave"
|
|
depends on EMBEDDED
|
|
select CPU_FREQ_GOV_POWERSAVE
|
|
help
|
|
Use the CPUFreq governor 'powersave' as default. This sets
|
|
the frequency statically to the lowest frequency supported by
|
|
the CPU.
|
|
|
|
config CPU_FREQ_DEFAULT_GOV_USERSPACE
|
|
bool "userspace"
|
|
select CPU_FREQ_GOV_USERSPACE
|
|
help
|
|
Use the CPUFreq governor 'userspace' as default. This allows
|
|
you to set the CPU frequency manually or when an userspace
|
|
program shall be able to set the CPU dynamically without having
|
|
to enable the userspace governor manually.
|
|
|
|
config CPU_FREQ_DEFAULT_GOV_ONDEMAND
|
|
bool "ondemand"
|
|
select CPU_FREQ_GOV_ONDEMAND
|
|
select CPU_FREQ_GOV_PERFORMANCE
|
|
help
|
|
Use the CPUFreq governor 'ondemand' as default. This allows
|
|
you to get a full dynamic frequency capable system by simply
|
|
loading your cpufreq low-level hardware driver.
|
|
Be aware that not all cpufreq drivers support the ondemand
|
|
governor. If unsure have a look at the help section of the
|
|
driver. Fallback governor will be the performance governor.
|
|
|
|
config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
|
|
bool "conservative"
|
|
select CPU_FREQ_GOV_CONSERVATIVE
|
|
select CPU_FREQ_GOV_PERFORMANCE
|
|
help
|
|
Use the CPUFreq governor 'conservative' as default. This allows
|
|
you to get a full dynamic frequency capable system by simply
|
|
loading your cpufreq low-level hardware driver.
|
|
Be aware that not all cpufreq drivers support the conservative
|
|
governor. If unsure have a look at the help section of the
|
|
driver. Fallback governor will be the performance governor.
|
|
endchoice
|
|
|
|
config CPU_FREQ_GOV_PERFORMANCE
|
|
tristate "'performance' governor"
|
|
help
|
|
This cpufreq governor sets the frequency statically to the
|
|
highest available CPU frequency.
|
|
|
|
To compile this driver as a module, choose M here: the
|
|
module will be called cpufreq_performance.
|
|
|
|
If in doubt, say Y.
|
|
|
|
config CPU_FREQ_GOV_POWERSAVE
|
|
tristate "'powersave' governor"
|
|
help
|
|
This cpufreq governor sets the frequency statically to the
|
|
lowest available CPU frequency.
|
|
|
|
To compile this driver as a module, choose M here: the
|
|
module will be called cpufreq_powersave.
|
|
|
|
If in doubt, say Y.
|
|
|
|
config CPU_FREQ_GOV_USERSPACE
|
|
tristate "'userspace' governor for userspace frequency scaling"
|
|
help
|
|
Enable this cpufreq governor when you either want to set the
|
|
CPU frequency manually or when an userspace program shall
|
|
be able to set the CPU dynamically, like on LART
|
|
<http://www.lartmaker.nl/>.
|
|
|
|
To compile this driver as a module, choose M here: the
|
|
module will be called cpufreq_userspace.
|
|
|
|
For details, take a look at <file:Documentation/cpu-freq/>.
|
|
|
|
If in doubt, say Y.
|
|
|
|
config CPU_FREQ_GOV_ONDEMAND
|
|
tristate "'ondemand' cpufreq policy governor"
|
|
select CPU_FREQ_TABLE
|
|
help
|
|
'ondemand' - This driver adds a dynamic cpufreq policy governor.
|
|
The governor does a periodic polling and
|
|
changes frequency based on the CPU utilization.
|
|
The support for this governor depends on CPU capability to
|
|
do fast frequency switching (i.e, very low latency frequency
|
|
transitions).
|
|
|
|
To compile this driver as a module, choose M here: the
|
|
module will be called cpufreq_ondemand.
|
|
|
|
For details, take a look at linux/Documentation/cpu-freq.
|
|
|
|
If in doubt, say N.
|
|
|
|
config CPU_FREQ_GOV_CONSERVATIVE
|
|
tristate "'conservative' cpufreq governor"
|
|
depends on CPU_FREQ
|
|
help
|
|
'conservative' - this driver is rather similar to the 'ondemand'
|
|
governor both in its source code and its purpose, the difference is
|
|
its optimisation for better suitability in a battery powered
|
|
environment. The frequency is gracefully increased and decreased
|
|
rather than jumping to 100% when speed is required.
|
|
|
|
If you have a desktop machine then you should really be considering
|
|
the 'ondemand' governor instead, however if you are using a laptop,
|
|
PDA or even an AMD64 based computer (due to the unacceptable
|
|
step-by-step latency issues between the minimum and maximum frequency
|
|
transitions in the CPU) you will probably want to use this governor.
|
|
|
|
To compile this driver as a module, choose M here: the
|
|
module will be called cpufreq_conservative.
|
|
|
|
For details, take a look at linux/Documentation/cpu-freq.
|
|
|
|
If in doubt, say N.
|
|
|
|
endif # CPU_FREQ
|