How to configure the Linux kernel/arch/i386/kernel/cpu/cpufreq

Howto configure the Linux kernel / arch / i386 / kernel / cpu / cpufreq


 * CPU Frequency scaling
 * CPU Frequency scaling

CPU Frequency scaling

 * Option: Howto configure the Linux kernel/drivers/cpufreq

CPU_FREQ

"CPUFreq processor drivers"


 * Option: X86_ACPI_CPUFREQ
 * Kernel Versions: 2.6.15.6 ...
 * (on/off/module) ACPI Processor P-States driver
 * select CPU_FREQ_TABLE
 * depends on ACPI_PROCESSOR
 * This driver adds a CPUFreq driver which utilizes the ACPI Processor Performance States.
 * For details, take a look at .
 * If in doubt, say N.


 * Option: ELAN_CPUFREQ
 * Kernel Versions: 2.6.15.6 ...
 * (on/off/module) AMD Elan SC400 and SC410
 * select CPU_FREQ_TABLE
 * depends on X86_ELAN
 * This adds the CPUFreq driver for AMD Elan SC400 and SC410 processors.
 * You need to specify the processor maximum speed as boot parameter: elanfreq=maxspeed (in kHz) or as module parameter "max_freq".
 * For details, take a look at .
 * If in doubt, say N.


 * Option: SC520_CPUFREQ
 * Kernel Versions: 2.6.15.6 ...
 * (on/off/module) AMD Elan SC520
 * select CPU_FREQ_TABLE
 * depends on X86_ELAN
 * This adds the CPUFreq driver for AMD Elan SC520 processor.
 * For details, take a look at .
 * If in doubt, say N.


 * Option: X86_POWERNOW_K6
 * Kernel Versions: 2.6.15.6 ...
 * (on/off/module) AMD Mobile K6-2/K6-3 PowerNow!
 * select CPU_FREQ_TABLE
 * This adds the CPUFreq driver for mobile AMD K6-2+ and mobile AMD K6-3+ processors.
 * For details, take a look at .
 * If in doubt, say N.


 * Option: X86_POWERNOW_K7
 * Kernel Versions: 2.6.15.6 ...
 * (on/off/module) AMD Mobile Athlon/Duron PowerNow!
 * select CPU_FREQ_TABLE
 * This adds the CPUFreq driver for mobile AMD K7 mobile processors.
 * For details, take a look at .
 * If in doubt, say N.


 * Option: X86_POWERNOW_K7_ACPI
 * Kernel Versions: 2.6.15.6 ...
 * (on/off)
 * depends on X86_POWERNOW_K7 && ACPI_PROCESSOR
 * depends on !(X86_POWERNOW_K7 = y && ACPI_PROCESSOR = m)
 * default y


 * Option: X86_POWERNOW_K8
 * Kernel Versions: 2.6.15.6 ...
 * (on/off/module) AMD Opteron/Athlon64 PowerNow!
 * select CPU_FREQ_TABLE
 * depends on EXPERIMENTAL
 * This adds the CPUFreq driver for mobile AMD Opteron/Athlon64 processors.
 * For details, take a look at .
 * If in doubt, say N.


 * Option: X86_POWERNOW_K8_ACPI
 * Kernel Versions: 2.6.15.6 ...
 * (on/off)
 * depends on X86_POWERNOW_K8 && ACPI_PROCESSOR
 * depends on !(X86_POWERNOW_K8 = y && ACPI_PROCESSOR = m)
 * default y

details, take a look at . in doubt, say N.
 * Option: X86_GX_SUSPMOD
 * Kernel Versions: 2.6.15.6 ...
 * (on/off/module) Cyrix MediaGX/NatSemi Geode Suspend Modulation
 * This add the CPUFreq driver for NatSemi Geode processors whichsupport suspend modulation.


 * Option: X86_SPEEDSTEP_CENTRINO
 * Kernel Versions: 2.6.15.6 ...
 * (on/off/module) Intel Enhanced SpeedStep
 * select CPU_FREQ_TABLE
 * select X86_SPEEDSTEP_CENTRINO_TABLE if (!X86_SPEEDSTEP_CENTRINO_ACPI)
 * This adds the CPUFreq driver for Enhanced SpeedStep enabled mobile CPUs. This means Intel Pentium M (Centrino) CPUs. However, you also need to say Y to "Use ACPI tables to decode..." below [which might imply enabling ACPI] if you want to use this driver on non-Banias CPUs.  For details, take a look at .  If in doubt, say N.


 * Option: X86_SPEEDSTEP_CENTRINO_ACPI
 * Kernel Versions: 2.6.15.6 ...
 * (on/off) Use ACPI tables to decode valid frequency/voltage pairs
 * depends on X86_SPEEDSTEP_CENTRINO && ACPI_PROCESSOR
 * depends on !(X86_SPEEDSTEP_CENTRINO = y && ACPI_PROCESSOR = m)
 * default y
 * Use primarily the information provided in the BIOS ACPI tables to determine valid CPU frequency and voltage pairings. It is required for the driver to work on non-Banias CPUs.
 * If in doubt, say Y.


 * Option: X86_SPEEDSTEP_CENTRINO_TABLE
 * Kernel Versions: 2.6.15.6 ...
 * (on/off) Built-in tables for Banias CPUs
 * depends on X86_SPEEDSTEP_CENTRINO
 * default y
 * Use built-in tables for Banias CPUs if ACPI encoding is not available.
 * If in doubt, say N.


 * Option: X86_SPEEDSTEP_ICH
 * Kernel Versions: 2.6.15.6 ...
 * (on/off/module) Intel Speedstep on ICH-M chipsets (ioport interface)
 * select CPU_FREQ_TABLE
 * This adds the CPUFreq driver for certain mobile Intel Pentium III (Coppermine), all mobile Intel Pentium III-M (Tualatin) and all mobile Intel Pentium 4 P4-M on systems which have an Intel ICH2, ICH3 or ICH4 southbridge.
 * For details, take a look at .
 * If in doubt, say N.


 * Option: X86_SPEEDSTEP_SMI
 * Kernel Versions: 2.6.15.6 ...
 * (on/off/module) Intel SpeedStep on 440BX/ZX/MX chipsets (SMI interface)
 * select CPU_FREQ_TABLE
 * depends on EXPERIMENTAL
 * This adds the CPUFreq driver for certain mobile Intel Pentium III (Coppermine), all mobile Intel Pentium III-M (Tualatin)  on systems which have an Intel 440BX/ZX/MX southbridge.
 * For details, take a look at .
 * If in doubt, say N.


 * Option: X86_P4_CLOCKMOD
 * Kernel Versions: 2.6.15.6 ...
 * (on/off/module) Intel Pentium 4 clock modulation
 * select CPU_FREQ_TABLE
 * This adds the CPUFreq driver for Intel Pentium 4 / XEON processors.
 * For details, take a look at .
 * If in doubt, say N.


 * Option: X86_CPUFREQ_NFORCE2
 * Kernel Versions: 2.6.15.6 ...
 * (on/off/module) nVidia nForce2 FSB changing
 * depends on EXPERIMENTAL
 * This adds the CPUFreq driver for FSB changing on nVidia nForce2 platforms.
 * For details, take a look at .
 * If in doubt, say N.


 * Option: X86_LONGRUN
 * Kernel Versions: 2.6.15.6 ...
 * (on/off/module) Transmeta LongRun
 * This adds the CPUFreq driver for Transmeta Crusoe and Efficeon processors which support LongRun.
 * For details, take a look at .
 * If in doubt, say N.


 * Option: X86_LONGHAUL
 * Kernel Versions: 2.6.15.6 ...
 * (on/off/module) VIA Cyrix III Longhaul
 * select CPU_FREQ_TABLE
 * This adds the CPUFreq driver for VIA Samuel/CyrixIII, VIA Cyrix Samuel/C3, VIA Cyrix Ezra and VIA Cyrix Ezra-T  processors.
 * For details, take a look at .
 * If in doubt, say N.

"shared options"


 * Option: X86_ACPI_CPUFREQ_PROC_INTF
 * Kernel Versions: 2.6.15.6 ...      bool /proc/acpi/processor/../performance interface (deprecated)
 * depends on PROC_FS
 * depends on X86_ACPI_CPUFREQ || X86_SPEEDSTEP_CENTRINO_ACPI || X86_POWERNOW_K7_ACPI || X86_POWERNOW_K8_ACPI
 * This enables the deprecated /proc/acpi/processor/../performance interface. While it is helpful for debugging, the generic, cross-architecture cpufreq interfaces should be used.
 * If in doubt, say N.


 * Option: X86_SPEEDSTEP_LIB
 * Kernel Versions: 2.6.15.6 ...
 * (on/off/module)
 * default X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI || X86_P4_CLOCKMOD


 * Option: X86_SPEEDSTEP_RELAXED_CAP_CHECK
 * Kernel Versions: 2.6.15.6 ...
 * (on/off) Relaxed speedstep capability checks
 * depends on (X86_SPEEDSTEP_SMI || X86_SPEEDSTEP_ICH)
 * Don't perform all checks for a speedstep capable system which would normally be done. Some ancient or strange systems, though speedstep  capable, don't always indicate that they are speedstep capable. This  option lets the probing code bypass some of those checks if the parameter "relaxed_check=1" is passed to the module.


 * CPU_FREQ

Linux Kernel Configuration