| Message ID | 20221117073541.3350600-5-Perry.Yuan@amd.com (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | AMD Pstate driver Urgent Change | expand |
On Thu, Nov 17, 2022 at 03:35:40PM +0800, Perry Yuan wrote: > Introduce the `amd_pstate` driver new working mode with > `amd_pstate=passive` added to kernel command line. > If there is no passive mode enabled by user, amd_pstate driver will be > disabled by default for now. > ><snipped>... > -.. _shared_mem: > - > -``shared_mem`` > -Use a module param (shared_mem) to enable related processors manually with > -**amd_pstate.shared_mem=1**. > -Due to the performance issue on the processors with `Shared Memory Support > -<perf_cap_>`_, we disable it presently and will re-enable this by default > -once we address performance issue with this solution. > - > -To check whether the current processor is using `Full MSR Support <perf_cap_>`_ > -or `Shared Memory Support <perf_cap_>`_ : :: > - > - ray@hr-test1:~$ lscpu | grep cppc > - Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpuid extd_apicid aperfmperf rapl pni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx f16c rdrand lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt tce topoext perfctr_core perfctr_nb bpext perfctr_llc mwaitx cpb cat_l3 cdp_l3 hw_pstate ssbd mba ibrs ibpb stibp vmmcall fsgsbase bmi1 avx2 smep bmi2 erms invpcid cqm rdt_a rdseed adx smap clflushopt clwb sha_ni xsaveopt xsavec xgetbv1 xsaves cqm_llc cqm_occup_llc cqm_mbm_total cqm_mbm_local clzero irperf xsaveerptr rdpru wbnoinvd cppc arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold avic v_vmsave_vmload vgif v_spec_ctrl umip pku ospke vaes vpclmulqdq rdpid overflow_recov succor smca fsrm > - > -If the CPU flags have ``cppc``, then this processor supports `Full MSR Support > -<perf_cap_>`_. Otherwise, it supports `Shared Memory Support <perf_cap_>`_. > +Passive Mode > +------------ > + > +``amd_pstate=passive`` > + > +It will be enabled if the ``amd_pstate=passive`` is passed to the kernel in the command line. > +In this mode, ``amd_pstate`` driver software specifies a desired QoS target in the CPPC > +performance scale as a relative number. This can be expressed as percentage of nominal > +performance (infrastructure max). Below the nominal sustained performance level, > +desired performance expresses the average performance level of the processor subject > +to the Performance Reduction Tolerance register. Above the nominal performance level, > +processor must provide at least nominal performance requested and go higher if current > +operating conditions allow. > > > ``cpupower`` tool support for ``amd-pstate`` > Why do you replace shared_mem subsection with passive mode section? It isn't be mentioned in the patch description.
[AMD Official Use Only - General] > -----Original Message----- > From: Bagas Sanjaya <bagasdotme@gmail.com> > Sent: Thursday, November 17, 2022 4:58 PM > To: Yuan, Perry <Perry.Yuan@amd.com> > Cc: rafael.j.wysocki@intel.com; Huang, Ray <Ray.Huang@amd.com>; > viresh.kumar@linaro.org; Limonciello, Mario > <Mario.Limonciello@amd.com>; Fontenot, Nathan > <Nathan.Fontenot@amd.com>; Deucher, Alexander > <Alexander.Deucher@amd.com>; Sharma, Deepak <Deepak.Sharma@amd.com>; > Huang, Shimmer <Shimmer.Huang@amd.com>; Meng, Li (Jassmine) > <Li.Meng@amd.com>; Du, Xiaojian <Xiaojian.Du@amd.com>; Karny, Wyes > <Wyes.Karny@amd.com>; Shenoy, Gautham Ranjal <gautham.shenoy@amd.com>; > Narayan, Ananth <Ananth.Narayan@amd.com>; linux-pm@vger.kernel.org; > linux- kernel@vger.kernel.org > Subject: Re: [PATCH v3 4/5] Documentation: amd-pstate: add driver > working mode introduction > > On Thu, Nov 17, 2022 at 03:35:40PM +0800, Perry Yuan wrote: > > Introduce the `amd_pstate` driver new working mode with > > `amd_pstate=passive` added to kernel command line. > > If there is no passive mode enabled by user, amd_pstate driver will > > be disabled by default for now. > > > ><snipped>... > > -.. _shared_mem: > > - > > -``shared_mem`` > > -Use a module param (shared_mem) to enable related processors > manually > >with -**amd_pstate.shared_mem=1**. > > -Due to the performance issue on the processors with `Shared Memory > >Support -<perf_cap_>`_, we disable it presently and will re-enable > >this by default -once we address performance issue with this solution. > > - > > -To check whether the current processor is using `Full MSR Support > ><perf_cap_>`_ -or `Shared Memory Support <perf_cap_>`_ : :: > > - > > - ray@hr-test1:~$ lscpu | grep cppc > > - Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge > mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext > fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc > cpuid extd_apicid aperfmperf rapl pni pclmulqdq monitor ssse3 fma cx16 > sse4_1 > sse4_2 x2apic movbe popcnt aes xsave avx f16c rdrand lahf_lm > cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch > osvw ibs skinit wdt tce topoext perfctr_core perfctr_nb bpext > perfctr_llc mwaitx cpb cat_l3 > cdp_l3 hw_pstate ssbd mba ibrs ibpb stibp vmmcall fsgsbase bmi1 avx2 > smep > bmi2 erms invpcid cqm rdt_a rdseed adx smap clflushopt clwb sha_ni > xsaveopt xsavec xgetbv1 xsaves cqm_llc cqm_occup_llc cqm_mbm_total > cqm_mbm_local clzero irperf xsaveerptr rdpru wbnoinvd cppc arat npt > lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists > pausefilter pfthreshold avic v_vmsave_vmload vgif v_spec_ctrl umip pku > ospke vaes vpclmulqdq rdpid overflow_recov succor smca fsrm > > - > > -If the CPU flags have ``cppc``, then this processor supports `Full > >MSR Support -<perf_cap_>`_. Otherwise, it supports `Shared Memory > Support <perf_cap_>`_. > > +Passive Mode > > +------------ > > + > > +``amd_pstate=passive`` > > + > > +It will be enabled if the ``amd_pstate=passive`` is passed to the > > +kernel in > the command line. > > +In this mode, ``amd_pstate`` driver software specifies a desired > > +QoS target in the CPPC performance scale as a relative number. This > > +can be expressed as percentage of nominal performance > > +(infrastructure max). Below the nominal sustained performance > > +level, desired performance expresses the average performance level > > +of the processor subject to the Performance Reduction Tolerance > > +register. Above the nominal performance level, processor must > > +provide at least nominal > performance requested and go higher if current operating conditions allow. > > > > > > ``cpupower`` tool support for ``amd-pstate`` > > > > Why do you replace shared_mem subsection with passive mode section? It > isn't be mentioned in the patch description. shared_mem is not needed any more, if no cppc flag detected for MSR support, pstate driver will use shared memory interface(cppc acpi) to set/get perf values to the low-level firmware. There are two type CPPC only in the amd cppc implementation. Removing shared_mem parameter will make it simple to load amd pstate driver now. Perry. > > -- > An old man doll... just what I always wanted! - Clara
diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst index 8f3d30c5a0d8..06e23538f79c 100644 --- a/Documentation/admin-guide/pm/amd-pstate.rst +++ b/Documentation/admin-guide/pm/amd-pstate.rst @@ -283,23 +283,19 @@ efficiency frequency management method on AMD processors. Kernel Module Options for ``amd-pstate`` ========================================= -.. _shared_mem: - -``shared_mem`` -Use a module param (shared_mem) to enable related processors manually with -**amd_pstate.shared_mem=1**. -Due to the performance issue on the processors with `Shared Memory Support -<perf_cap_>`_, we disable it presently and will re-enable this by default -once we address performance issue with this solution. - -To check whether the current processor is using `Full MSR Support <perf_cap_>`_ -or `Shared Memory Support <perf_cap_>`_ : :: - - ray@hr-test1:~$ lscpu | grep cppc - Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpuid extd_apicid aperfmperf rapl pni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx f16c rdrand lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt tce topoext perfctr_core perfctr_nb bpext perfctr_llc mwaitx cpb cat_l3 cdp_l3 hw_pstate ssbd mba ibrs ibpb stibp vmmcall fsgsbase bmi1 avx2 smep bmi2 erms invpcid cqm rdt_a rdseed adx smap clflushopt clwb sha_ni xsaveopt xsavec xgetbv1 xsaves cqm_llc cqm_occup_llc cqm_mbm_total cqm_mbm_local clzero irperf xsaveerptr rdpru wbnoinvd cppc arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold avic v_vmsave_vmload vgif v_spec_ctrl umip pku ospke vaes vpclmulqdq rdpid overflow_recov succor smca fsrm - -If the CPU flags have ``cppc``, then this processor supports `Full MSR Support -<perf_cap_>`_. Otherwise, it supports `Shared Memory Support <perf_cap_>`_. +Passive Mode +------------ + +``amd_pstate=passive`` + +It will be enabled if the ``amd_pstate=passive`` is passed to the kernel in the command line. +In this mode, ``amd_pstate`` driver software specifies a desired QoS target in the CPPC +performance scale as a relative number. This can be expressed as percentage of nominal +performance (infrastructure max). Below the nominal sustained performance level, +desired performance expresses the average performance level of the processor subject +to the Performance Reduction Tolerance register. Above the nominal performance level, +processor must provide at least nominal performance requested and go higher if current +operating conditions allow. ``cpupower`` tool support for ``amd-pstate``