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| author | Ethan Zhao <ethan.zhao@oracle.com> | 2014-12-09 10:43:19 +0900 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2014-12-11 00:23:48 +0100 |
| commit | aa4ea34da9e7a2bc0fb98f5add3e4e52872b7d45 (patch) | |
| tree | e1513de4b3a04ed9449a34468b82209f4dc068bc | |
| parent | 966916eabfb1726fec7ea7b69f0c7f5ce366e943 (diff) | |
| download | linux-stable-aa4ea34da9e7a2bc0fb98f5add3e4e52872b7d45.tar.gz linux-stable-aa4ea34da9e7a2bc0fb98f5add3e4e52872b7d45.tar.bz2 linux-stable-aa4ea34da9e7a2bc0fb98f5add3e4e52872b7d45.zip | |
intel_pstate: add kernel parameter to force loading
To force loading on Oracle Sun X86 servers, provide one kernel command line
parameter
intel_pstate = force
For those who are aware of the risk of no power capping capabily working
and try to get better performance with this driver.
Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
Tested-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Reviewed-by: Linda Knippers <linda.knippers@hp.com>
Acked-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | Documentation/kernel-parameters.txt | 9 | ||||
| -rw-r--r-- | drivers/cpufreq/intel_pstate.c | 6 |
2 files changed, 14 insertions, 1 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 5fdf714f40a0..d006bb22f3ca 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1446,6 +1446,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted. disable Do not enable intel_pstate as the default scaling driver for the supported processors + force + Enable intel_pstate on systems that prohibit it by default + in favor of acpi-cpufreq. Forcing the intel_pstate driver + instead of acpi-cpufreq may disable platform features, such + as thermal controls and power capping, that rely on ACPI + P-States information being indicated to OSPM and therefore + should be used with caution. This option does not work with + processors that aren't supported by the intel_pstate driver + or on platforms that use pcc-cpufreq instead of acpi-cpufreq. no_hwp Do not enable hardware P state control (HWP) if available. diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 1405b393c93d..0e841eecb743 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -948,6 +948,7 @@ static struct cpufreq_driver intel_pstate_driver = { static int __initdata no_load; static int __initdata no_hwp; +static unsigned int force_load; static int intel_pstate_msrs_not_valid(void) { @@ -1094,7 +1095,8 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void) case PSS: return intel_pstate_no_acpi_pss(); case PPC: - return intel_pstate_has_acpi_ppc(); + return intel_pstate_has_acpi_ppc() && + (!force_load); } } @@ -1175,6 +1177,8 @@ static int __init intel_pstate_setup(char *str) no_load = 1; if (!strcmp(str, "no_hwp")) no_hwp = 1; + if (!strcmp(str, "force")) + force_load = 1; return 0; } early_param("intel_pstate", intel_pstate_setup); |