From mboxrd@z Thu Jan 1 00:00:00 1970 From: ethan Subject: Re: [PATCH 2/2 v3] intel_pstate: add kernel parameter to enable loading on Sun X86 servers. Date: Wed, 26 Nov 2014 08:08:35 +0800 Message-ID: References: <1416891578-14171-1-git-send-email-ethan.zhao@oracle.com> <1416891578-14171-3-git-send-email-ethan.zhao@oracle.com> <54749777.7020802@intel.com> Mime-Version: 1.0 (1.0) Content-Type: text/plain; charset=gb2312 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <54749777.7020802@intel.com> Sender: linux-doc-owner@vger.kernel.org To: Dirk Brandewie Cc: Ethan Zhao , "linda.knippers@hp.com" , "viresh.kumar@linaro.org" , "rjw@rjwysocki.net" , "corbet@lwn.net" , "dirk.j.brandewie@intel.com" , "linux-doc@vger.kernel.org" , "linux-pm@vger.kernel.org" , "linux-kernel@vger.kernel.org" List-Id: linux-pm@vger.kernel.org Dirk, > =D4=DA 2014=C4=EA11=D4=C225=C8=D5=A3=AC22:51=A3=ACDirk Brandewie =D0=B4=B5=C0=A3=BA >=20 >> On 11/24/2014 08:59 PM, Ethan Zhao wrote: >> To force loading on Oracle Sun X86 servers, provide one kernel comma= nd line >> parameter >>=20 >> intel_pstate =3D onora >>=20 >> For those who be aware of the risk doing so. >>=20 >> Signed-off-by: Ethan Zhao >> --- >> v2: change to hardware vendor specific naming parameter. >>=20 >> Documentation/kernel-parameters.txt | 3 +++ >> drivers/cpufreq/intel_pstate.c | 6 +++++- >> 2 files changed, 8 insertions(+), 1 deletion(-) >>=20 >> diff --git a/Documentation/kernel-parameters.txt b/Documentation/ker= nel-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 a= lso 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. >=20 > What are the risks? What is the behaviour if platform power manageme= nt is > enabled and intel_pstate is trying to control P state selection as we= ll? So far test shows intel_pstate could run. >=20 > If intel_pstate will be able to successfully control P state selectio= n > with platform power management enabled then how about the name "oracl= e_force"? Oracle_force seems a suggestion from oracle, not an option would be use= d as choice In case of no other method. > Also the documentation should say what the risks are. The risk is the sever lost power capping capability, that may cause ser= vice down, for example, The server has two power supply units, one is faulty, without power cap= ping, could't limit the power consumption within one power supply's cap= ability, this could cause the last power supply Unit overload and power down. Thanks, Ethan >=20 >>=20 >> intremap=3D [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= =3D { >> }; >>=20 >> static int __initdata no_load; >> +static unsigned int load_on_sun; >>=20 >> static int intel_pstate_msrs_not_valid(void) >> { >> @@ -1005,7 +1006,8 @@ static bool intel_pstate_platform_pwr_mgmt_exi= sts(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; >> } >>=20 >> @@ -1080,6 +1082,8 @@ static int __init intel_pstate_setup(char *str= ) >>=20 >> if (!strcmp(str, "disable")) >> no_load =3D 1; >> + if (!strcmp(str, "onora")) >> + load_on_sun =3D 1; >> return 0; >> } >> early_param("intel_pstate", intel_pstate_setup); >=20