forked from Minki/linux
83fe27ea53
SRCU is not necessary to be compiled by default in all cases. For tinification efforts not compiling SRCU unless necessary is desirable. The current patch tries to make compiling SRCU optional by introducing a new Kconfig option CONFIG_SRCU which is selected when any of the components making use of SRCU are selected. If we do not select CONFIG_SRCU, srcu.o will not be compiled at all. text data bss dec hex filename 2007 0 0 2007 7d7 kernel/rcu/srcu.o Size of arch/powerpc/boot/zImage changes from text data bss dec hex filename 831552 64180 23944 919676 e087c arch/powerpc/boot/zImage : before 829504 64180 23952 917636 e0084 arch/powerpc/boot/zImage : after so the savings are about ~2000 bytes. Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com> CC: Josh Triplett <josh@joshtriplett.org> CC: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> [ paulmck: resolve conflict due to removal of arch/ia64/kvm/Kconfig. ]
92 lines
3.5 KiB
Plaintext
92 lines
3.5 KiB
Plaintext
menuconfig PM_DEVFREQ
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bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support"
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select SRCU
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help
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A device may have a list of frequencies and voltages available.
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devfreq, a generic DVFS framework can be registered for a device
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in order to let the governor provided to devfreq choose an
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operating frequency based on the device driver's policy.
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Each device may have its own governor and policy. Devfreq can
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reevaluate the device state periodically and/or based on the
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notification to "nb", a notifier block, of devfreq.
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Like some CPUs with CPUfreq, a device may have multiple clocks.
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However, because the clock frequencies of a single device are
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determined by the single device's state, an instance of devfreq
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is attached to a single device and returns a "representative"
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clock frequency of the device, which is also attached
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to a device by 1-to-1. The device registering devfreq takes the
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responsibility to "interpret" the representative frequency and
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to set its every clock accordingly with the "target" callback
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given to devfreq.
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When OPP is used with the devfreq device, it is recommended to
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register devfreq's nb to the OPP's notifier head. If OPP is
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used with the devfreq device, you may use OPP helper
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functions defined in devfreq.h.
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if PM_DEVFREQ
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comment "DEVFREQ Governors"
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config DEVFREQ_GOV_SIMPLE_ONDEMAND
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tristate "Simple Ondemand"
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help
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Chooses frequency based on the recent load on the device. Works
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similar as ONDEMAND governor of CPUFREQ does. A device with
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Simple-Ondemand should be able to provide busy/total counter
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values that imply the usage rate. A device may provide tuned
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values to the governor with data field at devfreq_add_device().
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config DEVFREQ_GOV_PERFORMANCE
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tristate "Performance"
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help
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Sets the frequency at the maximum available frequency.
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This governor always returns UINT_MAX as frequency so that
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the DEVFREQ framework returns the highest frequency available
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at any time.
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config DEVFREQ_GOV_POWERSAVE
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tristate "Powersave"
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help
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Sets the frequency at the minimum available frequency.
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This governor always returns 0 as frequency so that
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the DEVFREQ framework returns the lowest frequency available
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at any time.
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config DEVFREQ_GOV_USERSPACE
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tristate "Userspace"
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help
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Sets the frequency at the user specified one.
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This governor returns the user configured frequency if there
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has been an input to /sys/devices/.../power/devfreq_set_freq.
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Otherwise, the governor does not change the frequnecy
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given at the initialization.
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comment "DEVFREQ Drivers"
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config ARM_EXYNOS4_BUS_DEVFREQ
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bool "ARM Exynos4210/4212/4412 Memory Bus DEVFREQ Driver"
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depends on (CPU_EXYNOS4210 || SOC_EXYNOS4212 || SOC_EXYNOS4412) && !ARCH_MULTIPLATFORM
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select DEVFREQ_GOV_SIMPLE_ONDEMAND
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select PM_OPP
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help
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This adds the DEVFREQ driver for Exynos4210 memory bus (vdd_int)
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and Exynos4212/4412 memory interface and bus (vdd_mif + vdd_int).
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It reads PPMU counters of memory controllers and adjusts
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the operating frequencies and voltages with OPP support.
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This does not yet operate with optimal voltages.
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config ARM_EXYNOS5_BUS_DEVFREQ
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tristate "ARM Exynos5250 Bus DEVFREQ Driver"
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depends on SOC_EXYNOS5250
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select DEVFREQ_GOV_SIMPLE_ONDEMAND
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select PM_OPP
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help
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This adds the DEVFREQ driver for Exynos5250 bus interface (vdd_int).
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It reads PPMU counters of memory controllers and adjusts the
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operating frequencies and voltages with OPP support.
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endif # PM_DEVFREQ
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