amd-pstate preferred core
Subsystems (8)
v6 cover amd-pstate preferred core
Hi all:
The core frequency is subjected to the process variation in semiconductors. Not all cores are able to reach the maximum frequency respecting the infrastructure limits. Consequently, AMD has redefined the concept of maximum frequency of a part. This means that a fraction of cores can reach maximum frequency. To find the best process scheduling policy for a given scenario, OS needs to know the core ordering informed by the platform through highest performance capability register of the CPPC interface.
Earlier implementations of amd-pstate preferred core only support a static core ranking and targeted performance. Now it has the ability to dynamically change the preferred core based on the workload and platform conditions and accounting for thermals and aging.
Amd-pstate driver utilizes the functions and data structures provided by the ITMT architecture to enable the scheduler to favor scheduling on cores which can be get a higher frequency with lower voltage.
We call it amd-pstate preferred core.
Here sched_set_itmt_core_prio() is called to set priorities and sched_set_itmt_support() is called to enable ITMT feature. Amd-pstate driver uses the highest performance value to indicate the priority of CPU. The higher value has a higher priority.
Amd-pstate driver will provide an initial core ordering at boot time. It relies on the CPPC interface to communicate the core ranking to the operating system and scheduler to make sure that OS is choosing the cores with highest performance firstly for scheduling the process. When amd-pstate driver receives a message with the highest performance change, it will update the core ranking.
Changes form V5->V6:
- cpufreq: amd-pstate:
- - modify the wrong tag order.
- - modify warning about hw_prefcore sysfs attribute.
- - delete duplicate comments.
- - modify the variable name cppc_highest_perf to prefcore_ranking.
- - modify judgment conditions for setting highest_perf.
- - modify sysfs attribute for CPPC highest perf to pr_debug message.
- Documentation: amd-pstate:
- - modify warning: title underline too short.
Changes form V4->V5:
- cpufreq: amd-pstate:
- - modify sysfs attribute for CPPC highest perf.
- - modify warning about comments
- - rebase linux-next
- cpufreq:
- - Moidfy warning about function declarations.
- Documentation: amd-pstate:
- - align with ``amd-pstat``
Changes form V3->V4:
- Documentation: amd-pstate:
- - Modify inappropriate descriptions.
Changes form V2->V3:
- x86:
- - Modify kconfig and description.
- cpufreq: amd-pstate:
- - Add Co-developed-by tag in commit message.
- cpufreq:
- - Modify commit message.
- Documentation: amd-pstate:
- - Modify inappropriate descriptions.
Changes form V1->V2:
- acpi: cppc:
- - Add reference link.
- cpufreq:
- - Moidfy link error.
- cpufreq: amd-pstate:
- - Init the priorities of all online CPUs
- - Use a single variable to represent the status of preferred core.
- Documentation:
- - Default enabled preferred core.
- Documentation: amd-pstate:
- - Modify inappropriate descriptions.
- - Default enabled preferred core.
- - Use a single variable to represent the status of preferred core.
Meng Li (7):
x86: Drop CPU_SUP_INTEL from SCHED_MC_PRIO for the expansion.
acpi: cppc: Add get the highest performance cppc control
cpufreq: amd-pstate: Enable amd-pstate preferred core supporting.
cpufreq: Add a notification message that the highest perf has changed
cpufreq: amd-pstate: Update amd-pstate preferred core ranking
dynamically
Documentation: amd-pstate: introduce amd-pstate preferred core
Documentation: introduce amd-pstate preferrd core mode kernel command
line options
.../admin-guide/kernel-parameters.txt | 5 + Documentation/admin-guide/pm/amd-pstate.rst | 58 ++++++- arch/x86/Kconfig | 5 +- drivers/acpi/cppc_acpi.c | 13 ++ drivers/acpi/processor_driver.c | 6 + drivers/cpufreq/amd-pstate.c | 161 ++++++++++++++++-- drivers/cpufreq/cpufreq.c | 13 ++ include/acpi/cppc_acpi.h | 5 + include/linux/amd-pstate.h | 6 + include/linux/cpufreq.h | 5 + 10 files changed, 255 insertions(+), 22 deletions(-)
Signature · 1 line
2.34.1
PATCH v6 1/7 x86: Drop CPU_SUP_INTEL from SCHED_MC_PRIO for the expansion.
amd-pstate driver also uses SCHED_MC_PRIO, so decouple the requirement of CPU_SUP_INTEL from the dependencies to allow compilation in kernels without Intel CPU support.
--- arch/x86/Kconfig | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
arch/x86/Kconfig +3 -2
@@ -1054,8 +1054,9 @@ config SCHED_MC config SCHED_MC_PRIO bool "CPU core priorities scheduler support" - depends on SCHED_MC && CPU_SUP_INTEL - select X86_INTEL_PSTATE + depends on SCHED_MC + select X86_INTEL_PSTATE if CPU_SUP_INTEL + select X86_AMD_PSTATE if CPU_SUP_AMD select CPU_FREQ default y help
Signature · 1 line
2.34.1
kernel test robot
build botRe: [PATCH V6 1/7] x86: Drop CPU_SUP_INTEL from SCHED_MC_PRIO for the expansion.
kernel test robot noticed the following build errors:
Hi Meng,
kernel test robot noticed the following build errors:
[auto build test ERROR on rafael-pm/linux-next]
[also build test ERROR on tip/x86/core linus/master v6.6-rc1 next-20230912] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Meng-Li/x86-Drop-CPU_SUP_INTEL-from-SCHED_MC_PRIO-for-the-expansion/20230908-154939 base: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next patch link: https://lore.kernel.org/r/20230908074653.2799055-2-li.meng%40amd.com patch subject: [PATCH V6 1/7] x86: Drop CPU_SUP_INTEL from SCHED_MC_PRIO for the expansion. config: i386-buildonly-randconfig-004-20230913 (https://download.01.org/0day-ci/archive/20230913/[email protected]/config) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230913/[email protected]/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
All errors (new ones prefixed by >>):
In file included from drivers/cpufreq/amd-pstate.c:41:
>> include/acpi/processor.h:226:9: error: unknown type name 'phys_cpuid_t'
226 | phys_cpuid_t phys_id; /* CPU hardware ID such as APIC ID for x86 */
| ^~~~~~~~~~~~
include/acpi/processor.h:355:1: error: unknown type name 'phys_cpuid_t'
355 | phys_cpuid_t acpi_get_phys_id(acpi_handle, int type, u32 acpi_id);
| ^~~~~~~~~~~~
include/acpi/processor.h:356:1: error: unknown type name 'phys_cpuid_t'
356 | phys_cpuid_t acpi_map_madt_entry(u32 acpi_id);
| ^~~~~~~~~~~~
include/acpi/processor.h:357:20: error: unknown type name 'phys_cpuid_t'
357 | int acpi_map_cpuid(phys_cpuid_t phys_id, u32 acpi_id);
| ^~~~~~~~~~~~
drivers/cpufreq/amd-pstate.c: In function 'amd_pstate_acpi_pm_profile_server':
drivers/cpufreq/amd-pstate.c:1076:17: error: 'acpi_gbl_FADT' undeclared (first use in this function); did you mean 'acpi_table_fadt'?
1076 | switch (acpi_gbl_FADT.preferred_profile) {
| ^~~~~~~~~~~~~
| acpi_table_fadt
drivers/cpufreq/amd-pstate.c:1076:17: note: each undeclared identifier is reported only once for each function it appears in
drivers/cpufreq/amd-pstate.c: In function 'amd_pstate_acpi_pm_profile_undefined':
drivers/cpufreq/amd-pstate.c:1087:13: error: 'acpi_gbl_FADT' undeclared (first use in this function); did you mean 'acpi_table_fadt'?
1087 | if (acpi_gbl_FADT.preferred_profile == PM_UNSPECIFIED)
| ^~~~~~~~~~~~~
| acpi_table_fadtKconfig warnings: (for reference only)
WARNING: unmet direct dependencies detected for X86_AMD_PSTATE
Depends on [n]: CPU_FREQ [=y] && X86 [=y] && ACPI [=n]
Selected by [y]:
- SCHED_MC_PRIO [=y] && SCHED_MC [=y] && CPU_SUP_AMD [=y]
WARNING: unmet direct dependencies detected for VIDEO_OV7640
Depends on [n]: MEDIA_SUPPORT [=y] && VIDEO_DEV [=y] && VIDEO_CAMERA_SENSOR [=n]
Selected by [y]:
- VIDEO_GO7007 [=y] && MEDIA_SUPPORT [=y] && MEDIA_USB_SUPPORT [=y] && MEDIA_ANALOG_TV_SUPPORT [=y] && VIDEO_DEV [=y] && I2C [=y] && SND [=y] && USB [=y] && MEDIA_SUBDRV_AUTOSELECT [=y] && MEDIA_CAMERA_SUPPORT [=y]
vim +/phys_cpuid_t +226 include/acpi/processor.h
^1da177e4c3f41 Linus Torvalds 2005-04-16 222
^1da177e4c3f41 Linus Torvalds 2005-04-16 223 struct acpi_processor {
^1da177e4c3f41 Linus Torvalds 2005-04-16 224 acpi_handle handle;
^1da177e4c3f41 Linus Torvalds 2005-04-16 225 u32 acpi_id;
828aef376d7a12 Catalin Marinas 2015-03-24 @226 phys_cpuid_t phys_id; /* CPU hardware ID such as APIC ID for x86 */
af8f3f514d193e Hanjun Guo 2015-01-04 227 u32 id; /* CPU logical ID allocated by OS */
^1da177e4c3f41 Linus Torvalds 2005-04-16 228 u32 pblk;
^1da177e4c3f41 Linus Torvalds 2005-04-16 229 int performance_platform_limit;
01854e697a77a4 Luming Yu 2007-05-26 230 int throttling_platform_limit;
ff55a9cebab024 Len Brown 2007-06-02 231 /* 0 - states 0..n-th state available */
01854e697a77a4 Luming Yu 2007-05-26 232
^1da177e4c3f41 Linus Torvalds 2005-04-16 233 struct acpi_processor_flags flags;
^1da177e4c3f41 Linus Torvalds 2005-04-16 234 struct acpi_processor_power power;
^1da177e4c3f41 Linus Torvalds 2005-04-16 235 struct acpi_processor_performance *performance;
^1da177e4c3f41 Linus Torvalds 2005-04-16 236 struct acpi_processor_throttling throttling;
^1da177e4c3f41 Linus Torvalds 2005-04-16 237 struct acpi_processor_limit limit;
d9460fd227ed2c Zhang Rui 2008-01-17 238 struct thermal_cooling_device *cdev;
ac212b6980d8d5 Rafael J. Wysocki 2013-05-03 239 struct device *dev; /* Processor device. */
3000ce3c52f8b8 Rafael J. Wysocki 2019-10-16 240 struct freq_qos_request perflib_req;
3000ce3c52f8b8 Rafael J. Wysocki 2019-10-16 241 struct freq_qos_request thermal_req;
^1da177e4c3f41 Linus Torvalds 2005-04-16 242 };
^1da177e4c3f41 Linus Torvalds 2005-04-16 243 Signature · 2 lines
0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
PATCH v6 2/7 acpi: cppc: Add get the highest performance cppc control
In reply to Meng LiAdd support for getting the highest performance to the generic CPPC driver. This enables downstream drivers such as amd-pstate to discover and use these values.
Please refer to the ACPI_Spec for details on continuous performance control of CPPC.
--- drivers/acpi/cppc_acpi.c | 13 +++++++++++++ include/acpi/cppc_acpi.h | 5 +++++ 2 files changed, 18 insertions(+)
drivers/acpi/cppc_acpi.c +13 -0
@@ -1154,6 +1154,19 @@ int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf)return cppc_get_perf (cpunum,NOMINAL_PERF , nominal_perf); } +/** +* cppc_get_highest_perf - Get the highest performance register value. +* @cpunum: CPU from which to get highest performance. +* @highest_perf: Return address. +* +* Return: 0 for success, -EIO otherwise. +*/ +int cppc_get_highest_perf (int cpunum,u64 *highest_perf) +{ +return cppc_get_perf (cpunum,HIGHEST_PERF , highest_perf); +} +EXPORT_SYMBOL_GPL (cppc_get_highest_perf); +/** * cppc_get_epp_perf - Get the epp register value. * @cpunum: CPU from which to get epp preference value.
include/acpi/cppc_acpi.h +5 -0
@@ -139,6 +139,7 @@ struct cppc_cpudata {#ifdef CONFIG_ACPI_CPPC_LIB extern int cppc_get_desired_perf (int cpunum,u64 *desired_perf);extern int cppc_get_nominal_perf (int cpunum,u64 *nominal_perf); +extern int cppc_get_highest_perf (int cpunum,u64 *highest_perf);extern int cppc_get_perf_ctrs (int cpu,struct cppc_perf_fb_ctrs *perf_fb_ctrs);extern int cppc_set_perf (int cpu,struct cppc_perf_ctrls *perf_ctrls);extern int cppc_set_enable (int cpu,bool enable);
@@ -165,6 +166,10 @@ static inline int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf) {return -ENOTSUPP ; } +static inline int cppc_get_highest_perf (int cpunum,u64 *highest_perf) +{ +return -ENOTSUPP ; +}static inline int cppc_get_perf_ctrs (int cpu,struct cppc_perf_fb_ctrs *perf_fb_ctrs) {return -ENOTSUPP ;
Signature · 1 line
2.34.1
PATCH v6 3/7 cpufreq: amd-pstate: Enable amd-pstate preferred core supporting.
In reply to Meng Liamd-pstate driver utilizes the functions and data structures provided by the ITMT architecture to enable the scheduler to favor scheduling on cores which can be get a higher frequency with lower voltage. We call it amd-pstate preferrred core.
Here sched_set_itmt_core_prio() is called to set priorities and sched_set_itmt_support() is called to enable ITMT feature. amd-pstate driver uses the highest performance value to indicate the priority of CPU. The higher value has a higher priority.
The initial core rankings are set up by amd-pstate when the system boots.
Add device attribute for hardware preferred core. It will check if the processor and power firmware support preferred core feature.
Add device attribute for preferred core. Only when hardware supports preferred core and user set enabled in early parameter, it can be set to enabled.
Add one new early parameter disable to allow user to disable the preferred core.
--- drivers/cpufreq/amd-pstate.c | 125 ++++++++++++++++++++++++++++++----- 1 file changed, 109 insertions(+), 16 deletions(-)
drivers/cpufreq/amd-pstate.c +109 -16
@@ -37,6 +37,7 @@#include <linux/uaccess.h> #include <linux/static_call.h> #include <linux/amd-pstate.h> +#include <linux/topology.h> #include <acpi/processor.h> #include <acpi/cppc_acpi.h>
@@ -49,6 +50,8 @@#define AMD_PSTATE_TRANSITION_LATENCY 20000#define AMD_PSTATE_TRANSITION_DELAY 1000 +#define AMD_PSTATE_PREFCORE_THRESHOLD 166 +#define AMD_PSTATE_MAX_CPPC_PERF 255/* * TODO: We need more time to fine tune processors with shared memory solution
@@ -65,6 +68,12 @@ static struct cpufreq_driver amd_pstate_epp_driver;static int cppc_state =AMD_PSTATE_UNDEFINED ;static bool cppc_enabled; +/*HW preferred Core featue is supported*/ +static bool hw_prefcore = true; + +/*Preferred Core featue is supported*/ +static bool prefcore = true; +/* * AMD Energy Preference Performance (EPP) * The EPP is used in the CCLK DPM controller to drive
@@ -290,23 +299,21 @@ static inline int amd_pstate_enable(bool enable)static int pstate_init_perf (struct amd_cpudata *cpudata) {u64 cap1; -u32 highest_perf;int ret =rdmsrl_safe_on_cpu (cpudata->cpu,MSR_AMD_CPPC_CAP1 , &cap1);if (ret)return ret; -/* -* TODO: Introduce AMD specific power feature. -* -* CPPC entry doesn't indicate the highest performance in some ASICs. +/* For platforms that do not support the preferred core feature, the +* highest_pef may be configured with 166 or 255, to avoid max frequency +* calculated wrongly. we take the AMD_CPPC_HIGHEST_PERF(cap1) value as +* the default max perf. */ - highest_perf =amd_get_highest_perf (); -if (highest_perf >AMD_CPPC_HIGHEST_PERF (cap1)) - highest_perf =AMD_CPPC_HIGHEST_PERF (cap1); - -WRITE_ONCE (cpudata->highest_perf, highest_perf); +if (hw_prefcore) +WRITE_ONCE (cpudata->highest_perf,AMD_PSTATE_PREFCORE_THRESHOLD ); +else +WRITE_ONCE (cpudata->highest_perf,AMD_CPPC_HIGHEST_PERF (cap1));WRITE_ONCE (cpudata->nominal_perf,AMD_CPPC_NOMINAL_PERF (cap1));WRITE_ONCE (cpudata->lowest_nonlinear_perf,AMD_CPPC_LOWNONLIN_PERF (cap1));
@@ -318,17 +325,15 @@ static int pstate_init_perf(struct amd_cpudata *cpudata)static int cppc_init_perf (struct amd_cpudata *cpudata) {struct cppc_perf_caps cppc_perf; -u32 highest_perf;int ret =cppc_get_perf_caps (cpudata->cpu, &cppc_perf);if (ret)return ret; - highest_perf =amd_get_highest_perf (); -if (highest_perf > cppc_perf.highest_perf) - highest_perf = cppc_perf.highest_perf; - -WRITE_ONCE (cpudata->highest_perf, highest_perf); +if (hw_prefcore) +WRITE_ONCE (cpudata->highest_perf,AMD_PSTATE_PREFCORE_THRESHOLD ); +else +WRITE_ONCE (cpudata->highest_perf, cppc_perf.highest_perf);WRITE_ONCE (cpudata->nominal_perf, cppc_perf.nominal_perf); WRITE_ONCE(cpudata->lowest_nonlinear_perf,
@@ -676,6 +681,74 @@ static void amd_perf_ctl_reset(unsigned int cpu)wrmsrl_on_cpu (cpu,MSR_AMD_PERF_CTL ,0 ); } +/* +* Set amd-pstate preferred core enable can't be done directly from cpufreq callbacks +* due to locking, so queue the work for later. +*/ +static void amd_pstste_sched_prefcore_workfn (struct work_struct *work) +{ +sched_set_itmt_support (); +} +static DECLARE_WORK(sched_prefcore_work, amd_pstste_sched_prefcore_workfn); + +/* +* Get the highest performance register value. +* @cpu: CPU from which to get highest performance. +* @highest_perf: Return address. +* +* Return: 0 for success, -EIO otherwise. +*/ +static int amd_pstate_get_highest_perf (int cpu,u64 *highest_perf) +{ +int ret; + +if (boot_cpu_has (X86_FEATURE_CPPC )) { +u64 cap1; + + ret =rdmsrl_safe_on_cpu (cpu,MSR_AMD_CPPC_CAP1 , &cap1); +if (ret) +return ret; +WRITE_ONCE (*highest_perf,AMD_CPPC_HIGHEST_PERF (cap1)); + }else { + ret =cppc_get_highest_perf (cpu, highest_perf); + } + +return (ret); +} + +static void amd_pstate_init_prefcore (void ) +{ +int cpu, ret; +u64 highest_perf; + +if (!prefcore) +return ; + +for_each_online_cpu (cpu) { + ret =amd_pstate_get_highest_perf (cpu, &highest_perf); +if (ret) +break ; + +sched_set_itmt_core_prio (highest_perf, cpu); + +/* check if CPPC preferred core feature is enabled*/ +if (highest_perf ==AMD_PSTATE_MAX_CPPC_PERF ) { +pr_debug ("AMD CPPC preferred core is unsupported!\n" ); + hw_prefcore = false; + prefcore = false; +return ; + } + } + +/* +* This code can be run during CPU online under the +* CPU hotplug locks, so sched_set_amd_prefcore_support() +* cannot be called from here. Queue up a work item +* to invoke it. +*/ +schedule_work (&sched_prefcore_work); +} +static int amd_pstate_cpu_init (struct cpufreq_policy *policy) {int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret;
@@ -1037,6 +1110,12 @@ static ssize_t status_store(struct device *a, struct device_attribute *b,return ret <0 ? ret : count; } +static ssize_t prefcore_show (struct device *dev, +struct device_attribute *attr,char *buf) +{ +return sysfs_emit (buf,"%s\n" , prefcore ?"enabled" :"disabled" ); +} +cpufreq_freq_attr_ro (amd_pstate_max_freq);cpufreq_freq_attr_ro (amd_pstate_lowest_nonlinear_freq);
@@ -1044,6 +1123,7 @@ cpufreq_freq_attr_ro(amd_pstate_highest_perf);cpufreq_freq_attr_rw (energy_performance_preference);cpufreq_freq_attr_ro (energy_performance_available_preferences);static DEVICE_ATTR_RW (status); +static DEVICE_ATTR_RO (prefcore);static struct freq_attr *amd_pstate_attr[] = { &amd_pstate_max_freq,
@@ -1063,6 +1143,7 @@ static struct freq_attr *amd_pstate_epp_attr[] = {static struct attribute *pstate_global_attributes[] = { &dev_attr_status.attr, + &dev_attr_prefcore.attr,NULL };
@@ -1506,6 +1587,8 @@ static int __init amd_pstate_init(void) } } +amd_pstate_init_prefcore (); +return ret; global_attr_free:
@@ -1527,7 +1610,17 @@ static int __init amd_pstate_param(char *str)return amd_pstate_set_driver (mode_idx); } + +static int __init amd_prefcore_param (char *str) +{ +if (!strcmp (str,"disable" )) + prefcore = false; + +return 0 ; +} +early_param ("amd_pstate" , amd_pstate_param); +early_param ("amd_prefcore" , amd_prefcore_param);MODULE_AUTHOR ("Huang Rui <[email protected]>" );MODULE_DESCRIPTION ("AMD Processor P-state Frequency Driver" );
Signature · 1 line
2.34.1
Re: [PATCH V6 3/7] cpufreq: amd-pstate: Enable amd-pstate preferred core supporting.
Quoted 22 lines · Meng Li
drivers/cpufreq/amd-pstate.c +22
-0+static void amd_pstate_init_prefcore (void ) +{ +int cpu, ret; +u64 highest_perf; + +if (!prefcore) +return ; + +for_each_online_cpu (cpu) { + ret =amd_pstate_get_highest_perf (cpu, &highest_perf); +if (ret) +break ; + +sched_set_itmt_core_prio (highest_perf, cpu); + +/* check if CPPC preferred core feature is enabled*/ +if (highest_perf ==AMD_PSTATE_MAX_CPPC_PERF ) { +pr_debug ("AMD CPPC preferred core is unsupported!\n" ); + hw_prefcore = false; + prefcore = false; +return ; + }
drivers/cpufreq/amd-pstate.c static void amd_perf_ctl_reset(unsigned int cpu) · line 750
Quoted 10 lines
drivers/cpufreq/amd-pstate.c +10
-0+ } + +/* +* This code can be run during CPU online under the +* CPU hotplug locks, so sched_set_amd_prefcore_support() +* cannot be called from here. Queue up a work item +* to invoke it. +*/ +schedule_work (&sched_prefcore_work); +}
Brilliant, repost without addressing prior feedback.. :-(
RE: [PATCH V6 3/7] cpufreq: amd-pstate: Enable amd-pstate preferred core supporting.
[AMD Official Use Only - General]
Hi Peter:
Quoted 48 lines
-----Original Message-----
From: Peter Zijlstra <[email protected]>
Sent: Sunday, September 10, 2023 1:40 AM
To: Meng, Li (Jassmine) <[email protected]>
Cc: Rafael J . Wysocki <[email protected]>; Huang, Ray <[email protected]>; [email protected]; linux- [email protected]; [email protected]; [email protected]; Shuah Khan <[email protected]>; [email protected]; Fontenot, Nathan <[email protected]>; Sharma, Deepak <[email protected]>; Deucher, Alexander <[email protected]>; Limonciello, Mario <[email protected]>; Huang, Shimmer <[email protected]>; Yuan, Perry <[email protected]>; Du, Xiaojian <[email protected]>; Viresh Kumar <[email protected]>; Borislav Petkov <[email protected]>
Subject: Re: [PATCH V6 3/7] cpufreq: amd-pstate: Enable amd-pstate preferred core supporting.Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
Quoted 25 lines · Meng Li
drivers/cpufreq/amd-pstate.c +25
-0+static void amd_pstate_init_prefcore (void ) { +int cpu, ret; +u64 highest_perf; + +if (!prefcore) +return ; + +for_each_online_cpu (cpu) { + ret =amd_pstate_get_highest_perf (cpu, &highest_perf); +if (ret) +break ; + +sched_set_itmt_core_prio (highest_perf, cpu); + +/* check if CPPC preferred core feature is enabled*/ +if (highest_perf ==AMD_PSTATE_MAX_CPPC_PERF ) { +pr_debug ("AMD CPPC preferred core is unsupported!\n" ); + hw_prefcore = false; + prefcore = false; +return ; + } + } + +/* +* This code can be run during CPU online under the
Quoted 8 lines
drivers/cpufreq/amd-pstate.c static void amd_perf_ctl_reset(unsigned int cpu) · line 750
Quoted 6 lines
drivers/cpufreq/amd-pstate.c +6
-0+* CPU hotplug locks, so sched_set_amd_prefcore_support() +* cannot be called from here. Queue up a work item +* to invoke it. +*/ +schedule_work (&sched_prefcore_work); +}Brilliant, repost without addressing prior feedback.. :-(
[Meng, Li (Jassmine)]
I am very sorry that I did not receive your V5 review comments before sending V6 patches. However, thank you very much for your review.
I will solve them one by one in the future V7 patches.
Thank you very much!
PATCH v6 4/7 cpufreq: Add a notification message that the highest perf has changed
In reply to Meng LiACPI 6.5 section 8.4.6.1.1.1 specifies that Notify event 0x85 can be emmitted to cause the the OSPM to re-evaluate the highest performance register. Add support for this event.
--- drivers/acpi/processor_driver.c | 6 ++++++ drivers/cpufreq/cpufreq.c | 13 +++++++++++++ include/linux/cpufreq.h | 5 +++++ 3 files changed, 24 insertions(+)
drivers/acpi/processor_driver.c +6 -0
@@ -27,6 +27,7 @@#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80#define ACPI_PROCESSOR_NOTIFY_POWER 0x81#define ACPI_PROCESSOR_NOTIFY_THROTTLING 0x82 +#define ACPI_PROCESSOR_NOTIFY_HIGEST_PERF_CHANGED 0x85MODULE_AUTHOR ("Paul Diefenbaugh" );MODULE_DESCRIPTION ("ACPI Processor Driver" );
@@ -83,6 +84,11 @@ static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)acpi_bus_generate_netlink_event (device->pnp.device_class,dev_name (&device->dev), event,0 );break ; +case ACPI_PROCESSOR_NOTIFY_HIGEST_PERF_CHANGED : +cpufreq_update_highest_perf (pr->id); +acpi_bus_generate_netlink_event (device->pnp.device_class, +dev_name (&device->dev), event,0 ); +break ;default :acpi_handle_debug (handle,"Unsupported event [0x%x]\n" , event);break ;
drivers/cpufreq/cpufreq.c +13 -0
@@ -2718,6 +2718,19 @@ void cpufreq_update_limits(unsigned int cpu) }EXPORT_SYMBOL_GPL (cpufreq_update_limits); +/** +* cpufreq_update_highest_perf - Update highest performance for a given CPU. +* @cpu: CPU to update the highest performance for. +* +* Invoke the driver's ->update_highest_perf callback if present +*/ +void cpufreq_update_highest_perf (unsigned int cpu) +{ +if (cpufreq_driver->update_highest_perf) + cpufreq_driver->update_highest_perf (cpu); +} +EXPORT_SYMBOL_GPL (cpufreq_update_highest_perf); +/********************************************************************* * BOOST * *********************************************************************/
include/linux/cpufreq.h +5 -0
@@ -235,6 +235,7 @@ int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);void refresh_frequency_limits (struct cpufreq_policy *policy);void cpufreq_update_policy (unsigned int cpu);void cpufreq_update_limits (unsigned int cpu); +void cpufreq_update_highest_perf (unsigned int cpu);bool have_governor_per_policy (void );bool cpufreq_supports_freq_invariance (void );struct kobject *get_governor_parent_kobj (struct cpufreq_policy *policy);
@@ -263,6 +264,7 @@ static inline bool cpufreq_supports_freq_invariance(void) return false; }static inline void disable_cpufreq (void ) { } +static inline void cpufreq_update_highest_perf (unsigned int cpu) { }#endif #ifdef CONFIG_CPU_FREQ_STAT
@@ -380,6 +382,9 @@ struct cpufreq_driver {/* Called to update policy limits on firmware notifications. */ void (*update_limits)(unsigned int cpu); +/* Called to update highest performance on firmware notifications. */ +void (*update_highest_perf)(unsigned int cpu); +/* optional */ int (*bios_limit)(int cpu,unsigned int *limit);
Signature · 1 line
2.34.1
PATCH v6 5/7 cpufreq: amd-pstate: Update amd-pstate preferred core ranking dynamically
In reply to Meng LiPreferred core rankings can be changed dynamically by the platform based on the workload and platform conditions and accounting for thermals and aging.
When this occurs, cpu priority need to be set.
--- drivers/cpufreq/amd-pstate.c | 36 ++++++++++++++++++++++++++++++++++-- include/linux/amd-pstate.h | 6 ++++++ 2 files changed, 40 insertions(+), 2 deletions(-)
drivers/cpufreq/amd-pstate.c +34 -2
@@ -318,6 +318,7 @@ static int pstate_init_perf(struct amd_cpudata *cpudata)WRITE_ONCE (cpudata->nominal_perf,AMD_CPPC_NOMINAL_PERF (cap1));WRITE_ONCE (cpudata->lowest_nonlinear_perf,AMD_CPPC_LOWNONLIN_PERF (cap1));WRITE_ONCE (cpudata->lowest_perf,AMD_CPPC_LOWEST_PERF (cap1)); +WRITE_ONCE (cpudata->prefcore_ranking,AMD_CPPC_HIGHEST_PERF (cap1));return 0 ; }
@@ -339,6 +340,7 @@ static int cppc_init_perf(struct amd_cpudata *cpudata)WRITE_ONCE (cpudata->lowest_nonlinear_perf, cppc_perf.lowest_nonlinear_perf);WRITE_ONCE (cpudata->lowest_perf, cppc_perf.lowest_perf); +WRITE_ONCE (cpudata->prefcore_ranking, cppc_perf.highest_perf);if (cppc_state ==AMD_PSTATE_ACTIVE )return 0 ;
@@ -545,7 +547,7 @@ static void amd_pstate_adjust_perf(unsigned int cpu,if (target_perf < capacity) des_perf =DIV_ROUND_UP (cap_perf * target_perf, capacity); - min_perf =READ_ONCE (cpudata->highest_perf); + min_perf =READ_ONCE (cpudata->lowest_perf);if (_min_perf < capacity) min_perf =DIV_ROUND_UP (cap_perf * _min_perf, capacity);
@@ -749,6 +751,34 @@ static void amd_pstate_init_prefcore(void)schedule_work (&sched_prefcore_work); } +static void amd_pstate_update_highest_perf (unsigned int cpu) +{ +struct cpufreq_policy *policy; +struct amd_cpudata *cpudata; +u32 prev_high =0 , cur_high =0 ; +u64 highest_perf; +int ret; + +if (!prefcore) +return ; + + ret =amd_pstate_get_highest_perf (cpu, &highest_perf); +if (ret) +return ; + + policy =cpufreq_cpu_get (cpu); + cpudata = policy->driver_data; + cur_high = highest_perf; + prev_high =READ_ONCE (cpudata->prefcore_ranking); + +if (prev_high != cur_high) { +WRITE_ONCE (cpudata->prefcore_ranking, cur_high); +sched_set_itmt_core_prio (cur_high, cpu); + } + +cpufreq_cpu_put (policy); +} +static int amd_pstate_cpu_init (struct cpufreq_policy *policy) {int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret;
@@ -913,7 +943,7 @@ static ssize_t show_amd_pstate_highest_perf(struct cpufreq_policy *policy,u32 perf;struct amd_cpudata *cpudata = policy->driver_data; - perf =READ_ONCE (cpudata->highest_perf); + perf =READ_ONCE (cpudata->prefcore_ranking);return sysfs_emit (buf,"%u\n" , perf); }
@@ -1473,6 +1503,7 @@ static struct cpufreq_driver amd_pstate_driver = { .suspend = amd_pstate_cpu_suspend, .resume = amd_pstate_cpu_resume, .set_boost = amd_pstate_set_boost, + .update_highest_perf = amd_pstate_update_highest_perf, .name = "amd-pstate", .attr = amd_pstate_attr, };
@@ -1487,6 +1518,7 @@ static struct cpufreq_driver amd_pstate_epp_driver = { .online = amd_pstate_epp_cpu_online, .suspend = amd_pstate_epp_suspend, .resume = amd_pstate_epp_resume, + .update_highest_perf = amd_pstate_update_highest_perf, .name = "amd-pstate-epp", .attr = amd_pstate_epp_attr, };
include/linux/amd-pstate.h +6 -0
@@ -39,11 +39,16 @@ struct amd_aperf_mperf {* @cppc_req_cached: cached performance request hints * @highest_perf: the maximum performance an individual processor may reach, * assuming ideal conditions +* For platforms that do not support the preferred core feature, the +* highest_pef may be configured with 166 or 255, to avoid max frequency +* calculated wrongly. we take the fixed value as the highest_perf. * @nominal_perf: the maximum sustained performance level of the processor, * assuming ideal operating conditions * @lowest_nonlinear_perf: the lowest performance level at which nonlinear power * savings are achieved * @lowest_perf: the absolute lowest performance level of the processor +* @prefcore_ranking: the preferred core ranking, the higher value indicates a higher +* priority. * @max_freq: the frequency that mapped to highest_perf * @min_freq: the frequency that mapped to lowest_perf * @nominal_freq: the frequency that mapped to nominal_perf
@@ -70,6 +75,7 @@ struct amd_cpudata {u32 nominal_perf;u32 lowest_nonlinear_perf;u32 lowest_perf; +u32 prefcore_ranking;u32 max_freq;u32 min_freq;
Signature · 1 line
2.34.1
Re: [PATCH V6 5/7] cpufreq: amd-pstate: Update amd-pstate preferred core ranking dynamically
Quoted 17 lines · Meng Li
drivers/cpufreq/amd-pstate.c +17
-0+static void amd_pstate_update_highest_perf (unsigned int cpu) +{ +struct cpufreq_policy *policy; +struct amd_cpudata *cpudata; +u32 prev_high =0 , cur_high =0 ; +u64 highest_perf; +int ret; + +if (!prefcore) +return ; + + ret =amd_pstate_get_highest_perf (cpu, &highest_perf); +if (ret) +return ; + + policy =cpufreq_cpu_get (cpu); + cpudata = policy->driver_data;
drivers/cpufreq/amd-pstate.c static void amd_pstate_init_prefcore(void) · line 780
Quoted 10 lines
drivers/cpufreq/amd-pstate.c +10
-0+ cur_high = highest_perf; + prev_high =READ_ONCE (cpudata->prefcore_ranking); + +if (prev_high != cur_high) { +WRITE_ONCE (cpudata->prefcore_ranking, cur_high); +sched_set_itmt_core_prio (cur_high, cpu); + } + +cpufreq_cpu_put (policy); +}
Idem -- I told to clarify the u32 vs int thing, nothing here.
PATCH v6 6/7 Documentation: amd-pstate: introduce amd-pstate preferred core
In reply to Meng LiIntroduce amd-pstate preferred core.
check preferred core state:
$ cat /sys/devices/system/cpu/amd-pstate/prefcore
--- Documentation/admin-guide/pm/amd-pstate.rst | 58 ++++++++++++++++++++- 1 file changed, 56 insertions(+), 2 deletions(-)
Documentation/admin-guide/pm/amd-pstate.rst +56 -2
@@ -300,8 +300,8 @@ platforms. The AMD P-States mechanism is the more performance and energy efficiency frequency management method on AMD processors. -AMD Pstate Driver Operation Modes -================================= +``amd-pstate`` Driver Operation Modes +====================================== ``amd_pstate`` CPPC has 3 operation modes: autonomous (active) mode, non-autonomous (passive) mode and guided autonomous (guided) mode.
@@ -353,6 +353,48 @@ is activated. In this mode, driver requests minimum and maximum performance level and the platform autonomously selects a performance level in this range and appropriate to the current workload. +``amd-pstate`` Preferred Core +================================= + +The core frequency is subjected to the process variation in semiconductors. +Not all cores are able to reach the maximum frequency respecting the +infrastructure limits. Consequently, AMD has redefined the concept of +maximum frequency of a part. This means that a fraction of cores can reach +maximum frequency. To find the best process scheduling policy for a given +scenario, OS needs to know the core ordering informed by the platform through +highest performance capability register of the CPPC interface. + +``amd-pstate`` preferred core enables the scheduler to prefer scheduling on +cores that can achieve a higher frequency with lower voltage. The preferred +core rankings can dynamically change based on the workload, platform conditions, +thermals and ageing. + +The priority metric will be initialized by the ``amd-pstate`` driver. The ``amd-pstate`` +driver will also determine whether or not ``amd-pstate`` preferred core is +supported by the platform. + +``amd-pstate`` driver will provide an initial core ordering when the system boots. +The platform uses the CPPC interfaces to communicate the core ranking to the +operating system and scheduler to make sure that OS is choosing the cores +with highest performance firstly for scheduling the process. When ``amd-pstate`` +driver receives a message with the highest performance change, it will +update the core ranking and set the cpu's priority. + +``amd-pstate`` Preferred Core Switch +================================= +Kernel Parameters +----------------- + +``amd-pstate`` peferred core`` has two states: enable and disable. +Enable/disable states can be chosen by different kernel parameters. +Default enable ``amd-pstate`` preferred core. + +``amd_prefcore=disable`` + +For systems that support ``amd-pstate`` preferred core, the core rankings will +always be advertised by the platform. But OS can choose to ignore that via the +kernel parameter ``amd_prefcore=disable``. + User Space Interface in ``sysfs`` - General ===========================================
@@ -385,6 +427,18 @@ control its functionality at the system level. They are located in the to the operation mode represented by that string - or to be unregistered in the "disable" case. +``prefcore`` + Preferred core state of the driver: "enabled" or "disabled". + + "enabled" + Enable the ``amd-pstate`` preferred core. + + "disabled" + Disable the ``amd-pstate`` preferred core + + + This attribute is read-only to check the state of preferred core. + ``cpupower`` tool support for ``amd-pstate`` ===============================================
Signature · 1 line
2.34.1
PATCH v6 7/7 Documentation: introduce amd-pstate preferrd core mode kernel command line options
In reply to Meng Liamd-pstate driver support enable/disable preferred core. Default enabled on platforms supporting amd-pstate preferred core. Disable amd-pstate preferred core with "amd_prefcore=disable" added to the kernel command line.
--- Documentation/admin-guide/kernel-parameters.txt | 5 +++++ 1 file changed, 5 insertions(+)
Documentation/admin-guide/kernel-parameters.txt +5 -0
@@ -363,6 +363,11 @@ selects a performance level in this range and appropriate to the current workload. + amd_prefcore= + [X86] + disable + Disable amd-pstate preferred core. + amijoy.map= [HW,JOY] Amiga joystick support Map of devices attached to JOY0DAT and JOY1DAT Format: <a>,<b>
Signature · 1 line
2.34.1