On Fri, 28 Nov 2014 12:36:17 +0900
Ethan Zhao <ethan.z...@oracle.com> wrote:

> To force loading on Oracle Sun X86 servers, provide one kernel command line
> parameter
> 
>   intel_pstate = ora_force
> 
> For those who be aware of the risk of no power capping capabily working and
> try to get better performance with this driver.

So, is this something you'd expect users to use on production systems,
or is it just for debug?

Thanks,
Kristen

> 
> Signed-off-by: Ethan Zhao <ethan.z...@oracle.com>
> ---
>  v2: change to hardware vendor specific naming parameter.
>  v4: refine code and doc.
>  v5&v6: fix a typo in doc.
> 
>  Documentation/kernel-parameters.txt | 5 +++++
>  drivers/cpufreq/intel_pstate.c      | 6 +++++-
>  2 files changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/kernel-parameters.txt 
> b/Documentation/kernel-parameters.txt
> index 479f332..7d0983e 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -1446,6 +1446,11 @@ 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
> +                    ora_force
> +                      Force loading intel_pstate on Oracle Sun Servers(X86).
> +                      only for those who be aware of the risk of no power 
> capping
> +                      capability working and try to get better performance 
> with this
> +                      driver.
>  
>       intremap=       [X86-64, Intel-IOMMU]
>                       on      enable Interrupt Remapping (default)
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index 1bb62ca..2654e13 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -866,6 +866,7 @@ static struct cpufreq_driver intel_pstate_driver = {
>  };
>  
>  static int __initdata no_load;
> +static unsigned int  ora_force;
>  
>  static int intel_pstate_msrs_not_valid(void)
>  {
> @@ -1003,7 +1004,8 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void)
>                       case PSS:
>                               return intel_pstate_no_acpi_pss();
>                       case PCC:
> -                             return intel_pstate_has_acpi_ppc();
> +                             return intel_pstate_has_acpi_ppc() &&
> +                                     (!ora_force);
>                       }
>       }
>  
> @@ -1078,6 +1080,8 @@ static int __init intel_pstate_setup(char *str)
>  
>       if (!strcmp(str, "disable"))
>               no_load = 1;
> +     if (!strcmp(str, "ora_force"))
> +             ora_force = 1;
>       return 0;
>  }
>  early_param("intel_pstate", intel_pstate_setup);

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