From: Dirk Brandewie <dirk.brandewie@gmail.com>
To: Ethan Zhao <ethan.zhao@oracle.com>,
linda.knippers@hp.com, viresh.kumar@linaro.org,
rjw@rjwysocki.net, corbet@lwn.net
Cc: dirk.j.brandewie@intel.com, linux-doc@vger.kernel.org,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
ethan.kernel@gmail.com
Subject: Re: [PATCH 2/2 v3] intel_pstate: add kernel parameter to enable loading on Sun X86 servers.
Date: Tue, 25 Nov 2014 06:51:35 -0800 [thread overview]
Message-ID: <54749777.7020802@intel.com> (raw)
In-Reply-To: <1416891578-14171-3-git-send-email-ethan.zhao@oracle.com>
On 11/24/2014 08:59 PM, Ethan Zhao wrote:
> To force loading on Oracle Sun X86 servers, provide one kernel command line
> parameter
>
> intel_pstate = onora
>
> For those who be aware of the risk doing so.
>
> Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
> ---
> v2: change to hardware vendor specific naming parameter.
>
> Documentation/kernel-parameters.txt | 3 +++
> drivers/cpufreq/intel_pstate.c | 6 +++++-
> 2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index 479f332..e4b1b81 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -1446,6 +1446,9 @@ 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
> + onora
> + Enable loading intel_pstate on Oracle Sun Servers(X86).
> + only for those who be aware of the risk.
What are the risks? What is the behaviour if platform power management is
enabled and intel_pstate is trying to control P state selection as well?
If intel_pstate will be able to successfully control P state selection
with platform power management enabled then how about the name "oracle_force"?
Also the documentation should say what the risks are.
>
> 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 fa67fb3..e49b050 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 load_on_sun;
>
> static int intel_pstate_msrs_not_valid(void)
> {
> @@ -1005,7 +1006,8 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void)
> if (!strncmp(hdr.oem_id, v_info->oem_id, ACPI_OEM_ID_SIZE) &&
> !strncmp(hdr.oem_table_id, v_info->oem_table_id,
> ACPI_OEM_TABLE_ID_SIZE) &&
> - intel_pstate_has_acpi_ppc())
> + intel_pstate_has_acpi_ppc() &&
> + !load_on_sun)
> return true;
> }
>
> @@ -1080,6 +1082,8 @@ static int __init intel_pstate_setup(char *str)
>
> if (!strcmp(str, "disable"))
> no_load = 1;
> + if (!strcmp(str, "onora"))
> + load_on_sun = 1;
> return 0;
> }
> early_param("intel_pstate", intel_pstate_setup);
>
next prev parent reply other threads:[~2014-11-25 14:51 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-25 4:59 [PATCH 0/2 v3]intel_pstate: skip this driver if hit Sun X86 servers Ethan Zhao
2014-11-25 4:59 ` [PATCH 1/2 v3] intel_pstate: skip this driver if Sun server has _PPC method Ethan Zhao
2014-11-25 14:57 ` Dirk Brandewie
2014-11-26 0:15 ` ethan
2014-11-26 17:54 ` Linda Knippers
2014-11-26 20:50 ` Linda Knippers
2014-11-27 3:28 ` ethan zhao
2014-11-25 4:59 ` [PATCH 2/2 v3] intel_pstate: add kernel parameter to enable loading on Sun X86 servers Ethan Zhao
2014-11-25 14:51 ` Dirk Brandewie [this message]
2014-11-26 0:08 ` ethan
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