path: root/Documentation
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authorEthan Zhao <ethan.zhao@oracle.com>2014-12-09 10:43:19 +0900
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-12-11 00:23:48 +0100
commitaa4ea34da9e7a2bc0fb98f5add3e4e52872b7d45 (patch)
treee1513de4b3a04ed9449a34468b82209f4dc068bc /Documentation
parentintel_pstate: skip this driver if Sun server has _PPC method (diff)
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>
Diffstat (limited to 'Documentation')
1 files changed, 9 insertions, 0 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.
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.
Do not enable hardware P state control (HWP)
if available.