To force loading on Oracle Sun X86 servers, provide one kernel command line
parameter
intel_pstate = force
For those who be aware of the risk of no power capping capabily working and
try to get better performance with this driver.
Signed-off-by: Ethan Zhao <[email protected]>
Tested-by: Alexey Kodanev <[email protected]>
---
v2: change to hardware vendor specific naming parameter.
v4: refine code and doc.
v5&v6: fix a typo in doc.
v7: change enum PCC to PPC.
v8: change the name of kernel command line parameter to generic one.
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
+ force
+ Enable intel_pstate on systems where it may cause problems to
+ happen due to conflicts with platform firmware attempting to
+ drive P-states by itself in certain situations (for thermal
+ control or power capping in general or other purposes).
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 force_load;
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 PPC:
- return intel_pstate_has_acpi_ppc();
+ return intel_pstate_has_acpi_ppc() &&
+ (!force_load);
}
}
@@ -1078,6 +1080,8 @@ static int __init intel_pstate_setup(char *str)
if (!strcmp(str, "disable"))
no_load = 1;
+ if (!strcmp(str, "force"))
+ force_load = 1;
return 0;
}
early_param("intel_pstate", intel_pstate_setup);
--
1.8.3.1
On 12/5/2014 4:40 AM, Ethan Zhao wrote:
> To force loading on Oracle Sun X86 servers, provide one kernel command line
> parameter
>
> intel_pstate = force
>
> For those who be aware of the risk of no power capping capabily working and
> try to get better performance with this driver.
>
> Signed-off-by: Ethan Zhao <[email protected]>
> Tested-by: Alexey Kodanev <[email protected]>
> ---
> v2: change to hardware vendor specific naming parameter.
> v4: refine code and doc.
> v5&v6: fix a typo in doc.
> v7: change enum PCC to PPC.
> v8: change the name of kernel command line parameter to generic one.
>
> 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
> + force
> + Enable intel_pstate on systems where it may cause problems to
> + happen due to conflicts with platform firmware attempting to
> + drive P-states by itself in certain situations (for thermal
> + control or power capping in general or other purposes).
I suggest something like:
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-state information being
used by the OS and therefore should be used with care.
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.
Maybe this is too specific but I believe it is accurate. Comments?
-- ljk
>
> 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 force_load;
>
> 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 PPC:
> - return intel_pstate_has_acpi_ppc();
> + return intel_pstate_has_acpi_ppc() &&
> + (!force_load);
> }
> }
>
> @@ -1078,6 +1080,8 @@ static int __init intel_pstate_setup(char *str)
>
> if (!strcmp(str, "disable"))
> no_load = 1;
> + if (!strcmp(str, "force"))
> + force_load = 1;
> return 0;
> }
> early_param("intel_pstate", intel_pstate_setup);
>
On Friday, December 05, 2014 11:09:29 AM Linda Knippers wrote:
> On 12/5/2014 4:40 AM, Ethan Zhao wrote:
> > To force loading on Oracle Sun X86 servers, provide one kernel command line
> > parameter
> >
> > intel_pstate = force
> >
> > For those who be aware of the risk of no power capping capabily working and
> > try to get better performance with this driver.
> >
> > Signed-off-by: Ethan Zhao <[email protected]>
> > Tested-by: Alexey Kodanev <[email protected]>
> > ---
> > v2: change to hardware vendor specific naming parameter.
> > v4: refine code and doc.
> > v5&v6: fix a typo in doc.
> > v7: change enum PCC to PPC.
> > v8: change the name of kernel command line parameter to generic one.
> >
> > 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
> > + force
> > + Enable intel_pstate on systems where it may cause problems to
> > + happen due to conflicts with platform firmware attempting to
> > + drive P-states by itself in certain situations (for thermal
> > + control or power capping in general or other purposes).
>
> I suggest something like:
> 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-state information being
> used by the OS and therefore should be used with care.
> 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.
>
> Maybe this is too specific but I believe it is accurate. Comments?
Looks good to me, thanks!
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
Linda??
> ?? 2014??12??6?գ?00:09??Linda Knippers <[email protected]> д????
>
>> On 12/5/2014 4:40 AM, Ethan Zhao wrote:
>> To force loading on Oracle Sun X86 servers, provide one kernel command line
>> parameter
>>
>> intel_pstate = force
>>
>> For those who be aware of the risk of no power capping capabily working and
>> try to get better performance with this driver.
>>
>> Signed-off-by: Ethan Zhao <[email protected]>
>> Tested-by: Alexey Kodanev <[email protected]>
>> ---
>> v2: change to hardware vendor specific naming parameter.
>> v4: refine code and doc.
>> v5&v6: fix a typo in doc.
>> v7: change enum PCC to PPC.
>> v8: change the name of kernel command line parameter to generic one.
>>
>> 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
>> + force
>> + Enable intel_pstate on systems where it may cause problems to
>> + happen due to conflicts with platform firmware attempting to
>> + drive P-states by itself in certain situations (for thermal
>> + control or power capping in general or other purposes).
>
> I suggest something like:
> 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-state information being
P-States
> Used by the OS and therefore should be used with care.
Indicated to OSPM 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.
>
> Maybe this is too specific but I believe it is accurate. Comments?
>
Looks better to me, except some words commented.
Thanks,
Ethan
> -- ljk
>
>>
>> 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 force_load;
>>
>> 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 PPC:
>> - return intel_pstate_has_acpi_ppc();
>> + return intel_pstate_has_acpi_ppc() &&
>> + (!force_load);
>> }
>> }
>>
>> @@ -1078,6 +1080,8 @@ static int __init intel_pstate_setup(char *str)
>>
>> if (!strcmp(str, "disable"))
>> no_load = 1;
>> + if (!strcmp(str, "force"))
>> + force_load = 1;
>> return 0;
>> }
>> early_param("intel_pstate", intel_pstate_setup);
>
On 12/5/2014 9:16 PM, ethan wrote:
> Linda??
>
>> ?? 2014??12??6?գ?00:09??Linda Knippers <[email protected]> д????
>>
>>> On 12/5/2014 4:40 AM, Ethan Zhao wrote:
>>> To force loading on Oracle Sun X86 servers, provide one kernel command line
>>> parameter
>>>
>>> intel_pstate = force
>>>
>>> For those who be aware of the risk of no power capping capabily working and
>>> try to get better performance with this driver.
>>>
>>> Signed-off-by: Ethan Zhao <[email protected]>
>>> Tested-by: Alexey Kodanev <[email protected]>
>>> ---
>>> v2: change to hardware vendor specific naming parameter.
>>> v4: refine code and doc.
>>> v5&v6: fix a typo in doc.
>>> v7: change enum PCC to PPC.
>>> v8: change the name of kernel command line parameter to generic one.
>>>
>>> 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
>>> + force
>>> + Enable intel_pstate on systems where it may cause problems to
>>> + happen due to conflicts with platform firmware attempting to
>>> + drive P-states by itself in certain situations (for thermal
>>> + control or power capping in general or other purposes).
>>
>> I suggest something like:
>> 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-state information being
> P-States
>> Used by the OS and therefore should be used with care.
> Indicated to OSPM 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.
>>
>> Maybe this is too specific but I believe it is accurate. Comments?
>>
>
> Looks better to me, except some words commented.
Your suggestions look fine to me.
-- ljk
>
> Thanks,
> Ethan
>> -- ljk
>>
>>>
>>> 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 force_load;
>>>
>>> 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 PPC:
>>> - return intel_pstate_has_acpi_ppc();
>>> + return intel_pstate_has_acpi_ppc() &&
>>> + (!force_load);
>>> }
>>> }
>>>
>>> @@ -1078,6 +1080,8 @@ static int __init intel_pstate_setup(char *str)
>>>
>>> if (!strcmp(str, "disable"))
>>> no_load = 1;
>>> + if (!strcmp(str, "force"))
>>> + force_load = 1;
>>> return 0;
>>> }
>>> early_param("intel_pstate", intel_pstate_setup);
>>
> --
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