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* [PATCH v4 0/3] Add support for frequency invariance to AMD EPYC Zen2
@ 2020-11-12 18:26 Giovanni Gherdovich
  2020-11-12 18:26 ` [PATCH v4 1/3] x86, sched: Calculate frequency invariance for AMD systems Giovanni Gherdovich
                   ` (2 more replies)
  0 siblings, 3 replies; 12+ messages in thread
From: Giovanni Gherdovich @ 2020-11-12 18:26 UTC (permalink / raw)
  To: Borislav Petkov, Thomas Gleixner, Ingo Molnar, Peter Zijlstra,
	Len Brown, Rafael J . Wysocki
  Cc: Jon Grimm, Nathan Fontenot, Yazen Ghannam, Thomas Lendacky,
	Mel Gorman, Pu Wen, Viresh Kumar, Juri Lelli, Vincent Guittot,
	Dietmar Eggemann, Doug Smythies, x86, linux-pm, linux-kernel,
	linux-acpi, Giovanni Gherdovich

v3 at https://lore.kernel.org/lkml/20201110200519.18180-1-ggherdovich@suse.cz/

Changes wrt v3:

- Correct the #ifdef guard for cppc_get_perf_caps() from CONFIG_ACPI to
  CONFIG_ACPI_CPPC_LIB (reported by "kernel test robot <lkp@intel.com>")

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Cover Letter from v3:

v2 at https://lore.kernel.org/lkml/20201110183054.15883-1-ggherdovich@suse.cz/

Changes wrt v2:

- "code golf" on the function function init_freq_invariance_cppc().
  Make better use of the "secondary" argument to init_freq_invariance(),
  which was introduced at b56e7d45e807 ("x86, sched: Don't enable static key
  when starting secondary CPUs") to deal with CPU hotplug.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Cover Letter from v2:

v1 at https://lore.kernel.org/lkml/20201110083936.31994-1-ggherdovich@suse.cz/

Changes wrt v1:

- made initialization safe under CPU hotplug.
  The function init_freq_invariance_cppc now lets only the first caller
  into init_freq_invariance().

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Cover Letter from v1:

This series adds support for frequency invariant accounting on AMD EPYC Zen2
(aka "Rome"). The first patch by Nathan lays out the foundation by querying
ACPI infrastructure for the max boost frequency of the system. Specifically,
this value is available via the CPPC machinery; the previous EPYC generation,
namely Zen aka "Naples", doesn't implement that and frequency invariance won't
be supported.

The second patch sets the estimate for freq_max to be the midpoint between
max_boost and max_P, as that works slightly better in practice.

A side effect of this series is to provide, with the invariant schedutil
governor, a suitable baseline to evaluate a (still work-in-progress)
CPPC-based cpufreq driver for the AMD platform (see
https://lore.kernel.org/lkml/cover.1562781484.git.Janakarajan.Natarajan@amd.com
if/when it will resubmitted.


Giovanni Gherdovich (2):
  x86, sched: Use midpoint of max_boost and max_P for frequency
    invariance on AMD EPYC
  x86: Print ratio freq_max/freq_base used in frequency invariance
    calculations

Nathan Fontenot (1):
  x86, sched: Calculate frequency invariance for AMD systems

 arch/x86/include/asm/topology.h |  8 ++++
 arch/x86/kernel/smpboot.c       | 79 ++++++++++++++++++++++++++++++---
 drivers/acpi/cppc_acpi.c        |  3 ++
 3 files changed, 85 insertions(+), 5 deletions(-)

-- 
2.26.2


^ permalink raw reply	[flat|nested] 12+ messages in thread

* [PATCH v4 1/3] x86, sched: Calculate frequency invariance for AMD systems
  2020-11-12 18:26 [PATCH v4 0/3] Add support for frequency invariance to AMD EPYC Zen2 Giovanni Gherdovich
@ 2020-11-12 18:26 ` Giovanni Gherdovich
  2020-12-03  9:13   ` [tip: sched/core] " tip-bot2 for Nathan Fontenot
  2020-12-11  9:34   ` tip-bot2 for Nathan Fontenot
  2020-11-12 18:26 ` [PATCH v4 2/3] x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC Giovanni Gherdovich
  2020-11-12 18:26 ` [PATCH v4 3/3] x86: Print ratio freq_max/freq_base used in frequency invariance calculations Giovanni Gherdovich
  2 siblings, 2 replies; 12+ messages in thread
From: Giovanni Gherdovich @ 2020-11-12 18:26 UTC (permalink / raw)
  To: Borislav Petkov, Thomas Gleixner, Ingo Molnar, Peter Zijlstra,
	Len Brown, Rafael J . Wysocki
  Cc: Jon Grimm, Nathan Fontenot, Yazen Ghannam, Thomas Lendacky,
	Mel Gorman, Pu Wen, Viresh Kumar, Juri Lelli, Vincent Guittot,
	Dietmar Eggemann, Doug Smythies, x86, linux-pm, linux-kernel,
	linux-acpi, Nathan Fontenot, Giovanni Gherdovich

From: Nathan Fontenot <nathan.fontenot@amd.com>

This is the first pass in creating the ability to calculate the
frequency invariance on AMD systems. This approach uses the CPPC
highest performance and nominal performance values that range from
0 - 255 instead of a high and base frquency. This is because we do
not have the ability on AMD to get a highest frequency value.

On AMD systems the highest performance and nominal performance
vaues do correspond to the highest and base frequencies for the system
so using them should produce an appropriate ratio but some tweaking
is likely necessary.

Due to CPPC being initialized later in boot than when the frequency
invariant calculation is currently made, I had to create a callback
from the CPPC init code to do the calculation after we have CPPC
data.

Special thanks to "kernel test robot <lkp@intel.com>" for reporting that
compilation of drivers/acpi/cppc_acpi.c is conditional to
CONFIG_ACPI_CPPC_LIB, not just CONFIG_ACPI.

Signed-off-by: Nathan Fontenot <nathan.fontenot@amd.com>
[ ggherdovich@suse.cz: made safe under CPU hotplug, edited changelog ]
Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
---
 arch/x86/include/asm/topology.h |  8 ++++
 arch/x86/kernel/smpboot.c       | 76 ++++++++++++++++++++++++++++++---
 drivers/acpi/cppc_acpi.c        |  3 ++
 3 files changed, 82 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index f4234575f3fd..f66691d34f4a 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -218,4 +218,12 @@ static inline void arch_set_max_freq_ratio(bool turbo_disabled)
 }
 #endif
 
+#ifdef CONFIG_ACPI_CPPC_LIB
+void init_freq_invariance_cppc(void);
+#else
+static inline void init_freq_invariance_cppc(void)
+{
+}
+#endif
+
 #endif /* _ASM_X86_TOPOLOGY_H */
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index de776b2e6046..a4ab5cf6aeab 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -82,6 +82,10 @@
 #include <asm/hw_irq.h>
 #include <asm/stackprotector.h>
 
+#ifdef CONFIG_ACPI_CPPC_LIB
+#include <acpi/cppc_acpi.h>
+#endif
+
 /* representing HT siblings of each logical CPU */
 DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map);
 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
@@ -148,7 +152,7 @@ static inline void smpboot_restore_warm_reset_vector(void)
 	*((volatile u32 *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = 0;
 }
 
-static void init_freq_invariance(bool secondary);
+static void init_freq_invariance(bool secondary, bool cppc_ready);
 
 /*
  * Report back to the Boot Processor during boot time or to the caller processor
@@ -186,7 +190,7 @@ static void smp_callin(void)
 	 */
 	set_cpu_sibling_map(raw_smp_processor_id());
 
-	init_freq_invariance(true);
+	init_freq_invariance(true, false);
 
 	/*
 	 * Get our bogomips.
@@ -1340,7 +1344,7 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
 	set_sched_topology(x86_topology);
 
 	set_cpu_sibling_map(0);
-	init_freq_invariance(false);
+	init_freq_invariance(false, false);
 	smp_sanity_check();
 
 	switch (apic_intr_mode) {
@@ -2027,6 +2031,46 @@ static bool intel_set_max_freq_ratio(void)
 	return true;
 }
 
+#ifdef CONFIG_ACPI_CPPC_LIB
+static bool amd_set_max_freq_ratio(void)
+{
+	struct cppc_perf_caps perf_caps;
+	u64 highest_perf, nominal_perf;
+	u64 perf_ratio;
+	int rc;
+
+	rc = cppc_get_perf_caps(0, &perf_caps);
+	if (rc) {
+		pr_debug("Could not retrieve perf counters (%d)\n", rc);
+		return false;
+	}
+
+	highest_perf = perf_caps.highest_perf;
+	nominal_perf = perf_caps.nominal_perf;
+
+	if (!highest_perf || !nominal_perf) {
+		pr_debug("Could not retrieve highest or nominal performance\n");
+		return false;
+	}
+
+	perf_ratio = div_u64(highest_perf * SCHED_CAPACITY_SCALE, nominal_perf);
+	if (!perf_ratio) {
+		pr_debug("Non-zero highest/nominal perf values led to a 0 ratio\n");
+		return false;
+	}
+
+	arch_turbo_freq_ratio = perf_ratio;
+	arch_set_max_freq_ratio(false);
+
+	return true;
+}
+#else
+static bool amd_set_max_freq_ratio(void)
+{
+	return false;
+}
+#endif
+
 static void init_counter_refs(void)
 {
 	u64 aperf, mperf;
@@ -2038,7 +2082,7 @@ static void init_counter_refs(void)
 	this_cpu_write(arch_prev_mperf, mperf);
 }
 
-static void init_freq_invariance(bool secondary)
+static void init_freq_invariance(bool secondary, bool cppc_ready)
 {
 	bool ret = false;
 
@@ -2054,6 +2098,12 @@ static void init_freq_invariance(bool secondary)
 
 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
 		ret = intel_set_max_freq_ratio();
+	else if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
+		if (!cppc_ready) {
+			return;
+		}
+		ret = amd_set_max_freq_ratio();
+	}
 
 	if (ret) {
 		init_counter_refs();
@@ -2063,6 +2113,22 @@ static void init_freq_invariance(bool secondary)
 	}
 }
 
+#ifdef CONFIG_ACPI_CPPC_LIB
+static DEFINE_MUTEX(freq_invariance_lock);
+
+void init_freq_invariance_cppc(void)
+{
+	static bool secondary;
+
+	mutex_lock(&freq_invariance_lock);
+
+	init_freq_invariance(secondary, true);
+	secondary = true;
+
+	mutex_unlock(&freq_invariance_lock);
+}
+#endif
+
 static void disable_freq_invariance_workfn(struct work_struct *work)
 {
 	static_branch_disable(&arch_scale_freq_key);
@@ -2112,7 +2178,7 @@ void arch_scale_freq_tick(void)
 	schedule_work(&disable_freq_invariance_work);
 }
 #else
-static inline void init_freq_invariance(bool secondary)
+static inline void init_freq_invariance(bool secondary, bool cppc_ready)
 {
 }
 #endif /* CONFIG_X86_64 */
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 7a99b19bb893..368b13cb975d 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -39,6 +39,7 @@
 #include <linux/ktime.h>
 #include <linux/rwsem.h>
 #include <linux/wait.h>
+#include <linux/topology.h>
 
 #include <acpi/cppc_acpi.h>
 
@@ -850,6 +851,8 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
 		goto out_free;
 	}
 
+	init_freq_invariance_cppc();
+
 	kfree(output.pointer);
 	return 0;
 
-- 
2.26.2


^ permalink raw reply	[flat|nested] 12+ messages in thread

* [PATCH v4 2/3] x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC
  2020-11-12 18:26 [PATCH v4 0/3] Add support for frequency invariance to AMD EPYC Zen2 Giovanni Gherdovich
  2020-11-12 18:26 ` [PATCH v4 1/3] x86, sched: Calculate frequency invariance for AMD systems Giovanni Gherdovich
@ 2020-11-12 18:26 ` Giovanni Gherdovich
  2020-12-03  9:13   ` [tip: sched/core] " tip-bot2 for Giovanni Gherdovich
                     ` (2 more replies)
  2020-11-12 18:26 ` [PATCH v4 3/3] x86: Print ratio freq_max/freq_base used in frequency invariance calculations Giovanni Gherdovich
  2 siblings, 3 replies; 12+ messages in thread
From: Giovanni Gherdovich @ 2020-11-12 18:26 UTC (permalink / raw)
  To: Borislav Petkov, Thomas Gleixner, Ingo Molnar, Peter Zijlstra,
	Len Brown, Rafael J . Wysocki
  Cc: Jon Grimm, Nathan Fontenot, Yazen Ghannam, Thomas Lendacky,
	Mel Gorman, Pu Wen, Viresh Kumar, Juri Lelli, Vincent Guittot,
	Dietmar Eggemann, Doug Smythies, x86, linux-pm, linux-kernel,
	linux-acpi, Giovanni Gherdovich

Frequency invariant accounting calculations need the ratio
freq_curr/freq_max, but freq_max is unknown as it depends on dynamic power
allocation between cores: AMD EPYC CPUs implement "Core Performance Boost".
Three candidates are considered to estimate this value:

- maximum non-boost frequency
- maximum boost frequency
- the mid point between the above two

Experimental data on an AMD EPYC Zen2 machine slightly favors the third
option, which is applied with this patch.

The analysis uses the ondemand cpufreq governor as baseline, and compares
it with schedutil in a number of configurations. Using the freq_max value
described above offers a moderate advantage in performance and efficiency:

sugov-max (freq_max=max_boost) performs the worst on tbench: less
throughput and reduced efficiency than the other invariant-schedutil
options (see "Data Overview" below). Consider that tbench is generally a
problematic case as no schedutil version currently is better than ondemand.

sugov-P0 (freq_max=max_P) is the worst on dbench, while the other sugov's
can surpass ondemand with less filesystem latency and slightly increased
efficiency.

1. DATA OVERVIEW
2. DETAILED PERFORMANCE TABLES
3. POWER CONSUMPTION TABLE

1. DATA OVERVIEW
================

sugov-noinv : non-invariant schedutil governor
sugov-max   : invariant schedutil, freq_max=max_boost
sugov-mid   : invariant schedutil, freq_max=midpoint
sugov-P0    : invariant schedutil, freq_max=max_P
perfgov     : performance governor

driver      : acpi_cpufreq
machine     : AMD EPYC 7742 (Zen2, aka "Rome"), dual socket,
              128 cores / 256 threads, SATA SSD storage, 250G of memory,
	      XFS filesystem

Benchmarks are described in the next section.
Tilde (~) means the value is the same as baseline.

-------------------------------------------------------------------------------------
            ondemand  perfgov  sugov-noinv  sugov-max  sugov-mid  sugov-P0  better if
-------------------------------------------------------------------------------------
                                        PERFORMANCE RATIOS
tbench        1.00       1.44       0.90       0.87       0.93       0.93      higher
dbench        1.00       0.91       0.95       0.94       0.94       1.06      lower
kernbench     1.00       0.93       ~          ~          ~          0.97      lower
gitsource     1.00       0.66       0.97       0.96       ~          0.95      lower
-------------------------------------------------------------------------------------
                                    PERFORMANCE-PER-WATT RATIOS
tbench        1.00       1.16       0.84       0.84       0.88       0.85      higher
dbench        1.00       1.03       1.02       1.02       1.02       0.93      higher
kernbench     1.00       1.05       ~          ~          ~          ~         higher
gitsource     1.00       1.46       1.04       1.04       ~          1.05      higher

2. DETAILED PERFORMANCE TABLES
==============================

Benchmark          : tbench4 (i.e. dbench4 over the network, actually loopback)
Varying parameter  : number of clients
Unit               : MB/sec (higher is better)

                  5.9.0-ondemand (BASELINE)                   5.9.0-perfgov               5.9.0-sugov-noinv
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Hmean  1        427.19  +- 0.16% (        )     778.35  +- 0.10% (  82.20%)     346.92  +- 0.14% ( -18.79%)
Hmean  2        853.82  +- 0.09% (        )    1536.23  +- 0.03% (  79.93%)     694.36  +- 0.05% ( -18.68%)
Hmean  4       1657.54  +- 0.12% (        )    2938.18  +- 0.12% (  77.26%)    1362.81  +- 0.11% ( -17.78%)
Hmean  8       3301.87  +- 0.06% (        )    5679.10  +- 0.04% (  72.00%)    2693.35  +- 0.04% ( -18.43%)
Hmean  16      6139.65  +- 0.05% (        )    9498.81  +- 0.04% (  54.71%)    4889.97  +- 0.17% ( -20.35%)
Hmean  32     11170.28  +- 0.09% (        )   17393.25  +- 0.08% (  55.71%)    9104.55  +- 0.09% ( -18.49%)
Hmean  64     19322.97  +- 0.17% (        )   31573.91  +- 0.08% (  63.40%)   18552.52  +- 0.40% (  -3.99%)
Hmean  128    30383.71  +- 0.11% (        )   37416.91  +- 0.15% (  23.15%)   25938.70  +- 0.41% ( -14.63%)
Hmean  256    31143.96  +- 0.41% (        )   30908.76  +- 0.88% (  -0.76%)   29754.32  +- 0.24% (  -4.46%)
Hmean  512    30858.49  +- 0.26% (        )   38524.60  +- 1.19% (  24.84%)   42080.39  +- 0.56% (  36.37%)
Hmean  1024   39187.37  +- 0.19% (        )   36213.86  +- 0.26% (  -7.59%)   39555.98  +- 0.12% (   0.94%)

                            5.9.0-sugov-max                 5.9.0-sugov-mid                  5.9.0-sugov-P0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Hmean  1        352.59  +- 1.03% ( -17.46%)     352.08  +- 0.75% ( -17.58%)     352.31  +- 1.48% ( -17.53%)
Hmean  2        697.32  +- 0.08% ( -18.33%)     700.16  +- 0.20% ( -18.00%)     696.79  +- 0.06% ( -18.39%)
Hmean  4       1369.88  +- 0.04% ( -17.35%)    1369.72  +- 0.07% ( -17.36%)    1365.91  +- 0.05% ( -17.59%)
Hmean  8       2696.79  +- 0.04% ( -18.33%)    2711.06  +- 0.04% ( -17.89%)    2715.10  +- 0.61% ( -17.77%)
Hmean  16      4725.03  +- 0.03% ( -23.04%)    4875.65  +- 0.02% ( -20.59%)    4953.05  +- 0.28% ( -19.33%)
Hmean  32      9231.65  +- 0.10% ( -17.36%)    8704.89  +- 0.27% ( -22.07%)   10562.02  +- 0.36% (  -5.45%)
Hmean  64     15364.27  +- 0.19% ( -20.49%)   17786.64  +- 0.15% (  -7.95%)   19665.40  +- 0.22% (   1.77%)
Hmean  128    42100.58  +- 0.13% (  38.56%)   34946.28  +- 0.13% (  15.02%)   38635.79  +- 0.06% (  27.16%)
Hmean  256    30660.23  +- 1.08% (  -1.55%)   32307.67  +- 0.54% (   3.74%)   31153.27  +- 0.12% (   0.03%)
Hmean  512    24604.32  +- 0.14% ( -20.27%)   40408.50  +- 1.10% (  30.95%)   38800.29  +- 1.23% (  25.74%)
Hmean  1024   35535.47  +- 0.28% (  -9.32%)   41070.38  +- 2.56% (   4.81%)   31308.29  +- 2.52% ( -20.11%)

Benchmark          : dbench (filesystem stressor)
Varying parameter  : number of clients
Unit               : seconds (lower is better)

NOTE-1: This dbench version measures the average latency of a set of filesystem
        operations, as we found the traditional dbench metric (throughput) to be
	misleading.
NOTE-2: Due to high variability, we partition the original dataset and apply
        statistical bootrapping (a resampling method). Accuracy is reported in the
	form of 95% confidence intervals.

                  5.9.0-ondemand (BASELINE)                   5.9.0-perfgov               5.9.0-sugov-noinv
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
SubAmean  1         98.79  +- 0.92 (        )      83.36  +- 0.82 (  15.62%)      84.82  +- 0.92 (  14.14%)
SubAmean  2        116.00  +- 0.89 (        )     102.12  +- 0.77 (  11.96%)     109.63  +- 0.89 (   5.49%)
SubAmean  4        149.90  +- 1.03 (        )     132.12  +- 0.91 (  11.86%)     143.90  +- 1.15 (   4.00%)
SubAmean  8        182.41  +- 1.13 (        )     159.86  +- 0.93 (  12.36%)     165.82  +- 1.03 (   9.10%)
SubAmean  16       237.83  +- 1.23 (        )     219.46  +- 1.14 (   7.72%)     229.28  +- 1.19 (   3.59%)
SubAmean  32       334.34  +- 1.49 (        )     309.94  +- 1.42 (   7.30%)     321.19  +- 1.36 (   3.93%)
SubAmean  64       576.61  +- 2.16 (        )     540.75  +- 2.00 (   6.22%)     551.27  +- 1.99 (   4.39%)
SubAmean  128     1350.07  +- 4.14 (        )    1205.47  +- 3.20 (  10.71%)    1280.26  +- 3.75 (   5.17%)
SubAmean  256     3444.42  +- 7.97 (        )    3698.00 +- 27.43 (  -7.36%)    3494.14  +- 7.81 (  -1.44%)
SubAmean  2048   39457.89 +- 29.01 (        )   34105.33 +- 41.85 (  13.57%)   39688.52 +- 36.26 (  -0.58%)

                            5.9.0-sugov-max                 5.9.0-sugov-mid                  5.9.0-sugov-P0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
SubAmean  1         85.68  +- 1.04 (  13.27%)      84.16  +- 0.84 (  14.81%)      83.99  +- 0.90 (  14.99%)
SubAmean  2        108.42  +- 0.95 (   6.54%)     109.91  +- 1.39 (   5.24%)     112.06  +- 0.91 (   3.39%)
SubAmean  4        136.90  +- 1.04 (   8.67%)     137.59  +- 0.93 (   8.21%)     136.55  +- 0.95 (   8.91%)
SubAmean  8        163.15  +- 0.96 (  10.56%)     166.07  +- 1.02 (   8.96%)     165.81  +- 0.99 (   9.10%)
SubAmean  16       224.86  +- 1.12 (   5.45%)     223.83  +- 1.06 (   5.89%)     230.66  +- 1.19 (   3.01%)
SubAmean  32       320.51  +- 1.38 (   4.13%)     322.85  +- 1.49 (   3.44%)     321.96  +- 1.46 (   3.70%)
SubAmean  64       553.25  +- 1.93 (   4.05%)     554.19  +- 2.08 (   3.89%)     562.26  +- 2.22 (   2.49%)
SubAmean  128     1264.35  +- 3.72 (   6.35%)    1256.99  +- 3.46 (   6.89%)    2018.97 +- 18.79 ( -49.55%)
SubAmean  256     3466.25  +- 8.25 (  -0.63%)    3450.58  +- 8.44 (  -0.18%)    5032.12 +- 38.74 ( -46.09%)
SubAmean  2048   39133.10 +- 45.71 (   0.82%)   39905.95 +- 34.33 (  -1.14%)   53811.86 +-193.04 ( -36.38%)

Benchmark          : kernbench (kernel compilation)
Varying parameter  : number of jobs
Unit               : seconds (lower is better)

                  5.9.0-ondemand (BASELINE)                   5.9.0-perfgov               5.9.0-sugov-noinv
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean  2        471.71 +- 26.61% (        )     409.88 +- 16.99% (  13.11%)     430.63  +- 0.18% (   8.71%)
Amean  4        211.87  +- 0.58% (        )     194.03  +- 0.74% (   8.42%)     215.33  +- 0.64% (  -1.63%)
Amean  8        109.79  +- 1.27% (        )     101.43  +- 1.53% (   7.61%)     111.05  +- 1.95% (  -1.15%)
Amean  16        59.50  +- 1.28% (        )      55.61  +- 1.35% (   6.55%)      59.65  +- 1.78% (  -0.24%)
Amean  32        34.94  +- 1.22% (        )      32.36  +- 1.95% (   7.41%)      35.44  +- 0.63% (  -1.43%)
Amean  64        22.58  +- 0.38% (        )      20.97  +- 1.28% (   7.11%)      22.41  +- 1.73% (   0.74%)
Amean  128       17.72  +- 0.44% (        )      16.68  +- 0.32% (   5.88%)      17.65  +- 0.96% (   0.37%)
Amean  256       16.44  +- 0.53% (        )      15.76  +- 0.32% (   4.18%)      16.76  +- 0.60% (  -1.93%)
Amean  512       16.54  +- 0.21% (        )      15.62  +- 0.41% (   5.53%)      16.84  +- 0.85% (  -1.83%)

                            5.9.0-sugov-max                 5.9.0-sugov-mid                  5.9.0-sugov-P0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean  2        421.30  +- 0.24% (  10.69%)     419.26  +- 0.15% (  11.12%)     414.38  +- 0.33% (  12.15%)
Amean  4  	217.81  +- 5.53% (  -2.80%)     211.63  +- 0.99% (   0.12%)     208.43  +- 0.47% (   1.63%)
Amean  8  	108.80  +- 0.43% (   0.90%)     108.48  +- 1.44% (   1.19%)     108.59  +- 3.08% (   1.09%)
Amean  16 	 58.84  +- 0.74% (   1.12%)      58.37  +- 0.94% (   1.91%)      57.78  +- 0.78% (   2.90%)
Amean  32 	 34.04  +- 2.00% (   2.59%)      34.28  +- 1.18% (   1.91%)      33.98  +- 2.21% (   2.75%)
Amean  64 	 22.22  +- 1.69% (   1.60%)      22.27  +- 1.60% (   1.38%)      22.25  +- 1.41% (   1.47%)
Amean  128	 17.55  +- 0.24% (   0.97%)      17.53  +- 0.94% (   1.04%)      17.49  +- 0.43% (   1.30%)
Amean  256	 16.51  +- 0.46% (  -0.40%)      16.48  +- 0.48% (  -0.19%)      16.44  +- 1.21% (   0.00%)
Amean  512	 16.50  +- 0.35% (   0.19%)      16.35  +- 0.42% (   1.14%)      16.37  +- 0.33% (   0.99%)

Benchmark          : gitsource (time to run the git unit test suite)
Varying parameter  : none
Unit               : seconds (lower is better)

                  5.9.0-ondemand (BASELINE)                   5.9.0-perfgov               5.9.0-sugov-noinv
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean          1035.76  +- 0.30% (        )     688.21  +- 0.04% (  33.56%)    1003.85  +- 0.14% (   3.08%)

                            5.9.0-sugov-max                 5.9.0-sugov-mid                  5.9.0-sugov-P0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean           995.82  +- 0.08% (   3.86%)    1011.98  +- 0.03% (   2.30%)     986.87  +- 0.19% (   4.72%)

3. POWER CONSUMPTION TABLE
==========================

Average power consumption (watts).

--------------------------------------------------------------------------
            ondemand  perfgov  sugov-noinv  sugov-max  sugov-mid  sugov-P0
--------------------------------------------------------------------------
tbench4     227.25     281.83     244.17     236.76     241.50     247.99
dbench4     151.97     161.87     157.08     158.10     158.06     153.73
kernbench   162.78     167.22     162.90     164.19     164.65     164.72
gitsource   133.65     139.00     133.04     134.43     134.18     134.32

Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
---
 arch/x86/kernel/smpboot.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index a4ab5cf6aeab..c5dd5f6199d9 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -2054,6 +2054,8 @@ static bool amd_set_max_freq_ratio(void)
 	}
 
 	perf_ratio = div_u64(highest_perf * SCHED_CAPACITY_SCALE, nominal_perf);
+	/* midpoint between max_boost and max_P */
+	perf_ratio = (perf_ratio + SCHED_CAPACITY_SCALE) >> 1;
 	if (!perf_ratio) {
 		pr_debug("Non-zero highest/nominal perf values led to a 0 ratio\n");
 		return false;
-- 
2.26.2


^ permalink raw reply	[flat|nested] 12+ messages in thread

* [PATCH v4 3/3] x86: Print ratio freq_max/freq_base used in frequency invariance calculations
  2020-11-12 18:26 [PATCH v4 0/3] Add support for frequency invariance to AMD EPYC Zen2 Giovanni Gherdovich
  2020-11-12 18:26 ` [PATCH v4 1/3] x86, sched: Calculate frequency invariance for AMD systems Giovanni Gherdovich
  2020-11-12 18:26 ` [PATCH v4 2/3] x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC Giovanni Gherdovich
@ 2020-11-12 18:26 ` Giovanni Gherdovich
  2020-12-03  9:13   ` [tip: sched/core] " tip-bot2 for Giovanni Gherdovich
  2020-12-11  9:34   ` tip-bot2 for Giovanni Gherdovich
  2 siblings, 2 replies; 12+ messages in thread
From: Giovanni Gherdovich @ 2020-11-12 18:26 UTC (permalink / raw)
  To: Borislav Petkov, Thomas Gleixner, Ingo Molnar, Peter Zijlstra,
	Len Brown, Rafael J . Wysocki
  Cc: Jon Grimm, Nathan Fontenot, Yazen Ghannam, Thomas Lendacky,
	Mel Gorman, Pu Wen, Viresh Kumar, Juri Lelli, Vincent Guittot,
	Dietmar Eggemann, Doug Smythies, x86, linux-pm, linux-kernel,
	linux-acpi, Giovanni Gherdovich

The value freq_max/freq_base is a fundamental component of frequency
invariance calculations. It may come from a variety of sources such as MSRs
or ACPI data, tracking it down when troubleshooting a system could be
non-trivial. It is worth saving it in the kernel logs.

 # dmesg | grep 'Estimated ratio of average max'
 [   14.024036] smpboot: Estimated ratio of average max frequency by base frequency (times 1024): 1289

Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
---
 arch/x86/kernel/smpboot.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index c5dd5f6199d9..3577bb756d64 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -2110,6 +2110,7 @@ static void init_freq_invariance(bool secondary, bool cppc_ready)
 	if (ret) {
 		init_counter_refs();
 		static_branch_enable(&arch_scale_freq_key);
+		pr_info("Estimated ratio of average max frequency by base frequency (times 1024): %llu\n", arch_max_freq_ratio);
 	} else {
 		pr_debug("Couldn't determine max cpu frequency, necessary for scale-invariant accounting.\n");
 	}
-- 
2.26.2


^ permalink raw reply	[flat|nested] 12+ messages in thread

* [tip: sched/core] x86: Print ratio freq_max/freq_base used in frequency invariance calculations
  2020-11-12 18:26 ` [PATCH v4 3/3] x86: Print ratio freq_max/freq_base used in frequency invariance calculations Giovanni Gherdovich
@ 2020-12-03  9:13   ` tip-bot2 for Giovanni Gherdovich
  2020-12-11  9:34   ` tip-bot2 for Giovanni Gherdovich
  1 sibling, 0 replies; 12+ messages in thread
From: tip-bot2 for Giovanni Gherdovich @ 2020-12-03  9:13 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Giovanni Gherdovich, Peter Zijlstra (Intel), x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     24f326686c925a848d603a2c22f1f6ed1b7786e2
Gitweb:        https://git.kernel.org/tip/24f326686c925a848d603a2c22f1f6ed1b7786e2
Author:        Giovanni Gherdovich <ggherdovich@suse.cz>
AuthorDate:    Thu, 12 Nov 2020 19:26:14 +01:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 03 Dec 2020 10:00:35 +01:00

x86: Print ratio freq_max/freq_base used in frequency invariance calculations

The value freq_max/freq_base is a fundamental component of frequency
invariance calculations. It may come from a variety of sources such as MSRs
or ACPI data, tracking it down when troubleshooting a system could be
non-trivial. It is worth saving it in the kernel logs.

 # dmesg | grep 'Estimated ratio of average max'
 [   14.024036] smpboot: Estimated ratio of average max frequency by base frequency (times 1024): 1289

Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201112182614.10700-4-ggherdovich@suse.cz
---
 arch/x86/kernel/smpboot.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index c5dd5f6..3577bb7 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -2110,6 +2110,7 @@ static void init_freq_invariance(bool secondary, bool cppc_ready)
 	if (ret) {
 		init_counter_refs();
 		static_branch_enable(&arch_scale_freq_key);
+		pr_info("Estimated ratio of average max frequency by base frequency (times 1024): %llu\n", arch_max_freq_ratio);
 	} else {
 		pr_debug("Couldn't determine max cpu frequency, necessary for scale-invariant accounting.\n");
 	}

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [tip: sched/core] x86, sched: Calculate frequency invariance for AMD systems
  2020-11-12 18:26 ` [PATCH v4 1/3] x86, sched: Calculate frequency invariance for AMD systems Giovanni Gherdovich
@ 2020-12-03  9:13   ` tip-bot2 for Nathan Fontenot
  2020-12-11  9:34   ` tip-bot2 for Nathan Fontenot
  1 sibling, 0 replies; 12+ messages in thread
From: tip-bot2 for Nathan Fontenot @ 2020-12-03  9:13 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Giovanni Gherdovich, Nathan Fontenot, Peter Zijlstra (Intel),
	x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     0edb0fb35fa687e633322d23e5f44b7cfd21a5c5
Gitweb:        https://git.kernel.org/tip/0edb0fb35fa687e633322d23e5f44b7cfd21a5c5
Author:        Nathan Fontenot <nathan.fontenot@amd.com>
AuthorDate:    Thu, 12 Nov 2020 19:26:12 +01:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 03 Dec 2020 10:00:34 +01:00

x86, sched: Calculate frequency invariance for AMD systems

This is the first pass in creating the ability to calculate the
frequency invariance on AMD systems. This approach uses the CPPC
highest performance and nominal performance values that range from
0 - 255 instead of a high and base frquency. This is because we do
not have the ability on AMD to get a highest frequency value.

On AMD systems the highest performance and nominal performance
vaues do correspond to the highest and base frequencies for the system
so using them should produce an appropriate ratio but some tweaking
is likely necessary.

Due to CPPC being initialized later in boot than when the frequency
invariant calculation is currently made, I had to create a callback
from the CPPC init code to do the calculation after we have CPPC
data.

Special thanks to "kernel test robot <lkp@intel.com>" for reporting that
compilation of drivers/acpi/cppc_acpi.c is conditional to
CONFIG_ACPI_CPPC_LIB, not just CONFIG_ACPI.

[ ggherdovich@suse.cz: made safe under CPU hotplug, edited changelog ]
Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Signed-off-by: Nathan Fontenot <nathan.fontenot@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201112182614.10700-2-ggherdovich@suse.cz
---
 arch/x86/include/asm/topology.h |  5 ++-
 arch/x86/kernel/smpboot.c       | 76 +++++++++++++++++++++++++++++---
 drivers/acpi/cppc_acpi.c        |  7 +++-
 3 files changed, 83 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index f423457..488a8e8 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -218,4 +218,9 @@ static inline void arch_set_max_freq_ratio(bool turbo_disabled)
 }
 #endif
 
+#ifdef CONFIG_ACPI_CPPC_LIB
+void init_freq_invariance_cppc(void);
+#define init_freq_invariance_cppc init_freq_invariance_cppc
+#endif
+
 #endif /* _ASM_X86_TOPOLOGY_H */
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index de776b2..a4ab5cf 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -82,6 +82,10 @@
 #include <asm/hw_irq.h>
 #include <asm/stackprotector.h>
 
+#ifdef CONFIG_ACPI_CPPC_LIB
+#include <acpi/cppc_acpi.h>
+#endif
+
 /* representing HT siblings of each logical CPU */
 DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map);
 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
@@ -148,7 +152,7 @@ static inline void smpboot_restore_warm_reset_vector(void)
 	*((volatile u32 *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = 0;
 }
 
-static void init_freq_invariance(bool secondary);
+static void init_freq_invariance(bool secondary, bool cppc_ready);
 
 /*
  * Report back to the Boot Processor during boot time or to the caller processor
@@ -186,7 +190,7 @@ static void smp_callin(void)
 	 */
 	set_cpu_sibling_map(raw_smp_processor_id());
 
-	init_freq_invariance(true);
+	init_freq_invariance(true, false);
 
 	/*
 	 * Get our bogomips.
@@ -1340,7 +1344,7 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
 	set_sched_topology(x86_topology);
 
 	set_cpu_sibling_map(0);
-	init_freq_invariance(false);
+	init_freq_invariance(false, false);
 	smp_sanity_check();
 
 	switch (apic_intr_mode) {
@@ -2027,6 +2031,46 @@ out:
 	return true;
 }
 
+#ifdef CONFIG_ACPI_CPPC_LIB
+static bool amd_set_max_freq_ratio(void)
+{
+	struct cppc_perf_caps perf_caps;
+	u64 highest_perf, nominal_perf;
+	u64 perf_ratio;
+	int rc;
+
+	rc = cppc_get_perf_caps(0, &perf_caps);
+	if (rc) {
+		pr_debug("Could not retrieve perf counters (%d)\n", rc);
+		return false;
+	}
+
+	highest_perf = perf_caps.highest_perf;
+	nominal_perf = perf_caps.nominal_perf;
+
+	if (!highest_perf || !nominal_perf) {
+		pr_debug("Could not retrieve highest or nominal performance\n");
+		return false;
+	}
+
+	perf_ratio = div_u64(highest_perf * SCHED_CAPACITY_SCALE, nominal_perf);
+	if (!perf_ratio) {
+		pr_debug("Non-zero highest/nominal perf values led to a 0 ratio\n");
+		return false;
+	}
+
+	arch_turbo_freq_ratio = perf_ratio;
+	arch_set_max_freq_ratio(false);
+
+	return true;
+}
+#else
+static bool amd_set_max_freq_ratio(void)
+{
+	return false;
+}
+#endif
+
 static void init_counter_refs(void)
 {
 	u64 aperf, mperf;
@@ -2038,7 +2082,7 @@ static void init_counter_refs(void)
 	this_cpu_write(arch_prev_mperf, mperf);
 }
 
-static void init_freq_invariance(bool secondary)
+static void init_freq_invariance(bool secondary, bool cppc_ready)
 {
 	bool ret = false;
 
@@ -2054,6 +2098,12 @@ static void init_freq_invariance(bool secondary)
 
 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
 		ret = intel_set_max_freq_ratio();
+	else if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
+		if (!cppc_ready) {
+			return;
+		}
+		ret = amd_set_max_freq_ratio();
+	}
 
 	if (ret) {
 		init_counter_refs();
@@ -2063,6 +2113,22 @@ static void init_freq_invariance(bool secondary)
 	}
 }
 
+#ifdef CONFIG_ACPI_CPPC_LIB
+static DEFINE_MUTEX(freq_invariance_lock);
+
+void init_freq_invariance_cppc(void)
+{
+	static bool secondary;
+
+	mutex_lock(&freq_invariance_lock);
+
+	init_freq_invariance(secondary, true);
+	secondary = true;
+
+	mutex_unlock(&freq_invariance_lock);
+}
+#endif
+
 static void disable_freq_invariance_workfn(struct work_struct *work)
 {
 	static_branch_disable(&arch_scale_freq_key);
@@ -2112,7 +2178,7 @@ error:
 	schedule_work(&disable_freq_invariance_work);
 }
 #else
-static inline void init_freq_invariance(bool secondary)
+static inline void init_freq_invariance(bool secondary, bool cppc_ready)
 {
 }
 #endif /* CONFIG_X86_64 */
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 7a99b19..a852dc4 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -39,6 +39,7 @@
 #include <linux/ktime.h>
 #include <linux/rwsem.h>
 #include <linux/wait.h>
+#include <linux/topology.h>
 
 #include <acpi/cppc_acpi.h>
 
@@ -688,6 +689,10 @@ static bool is_cppc_supported(int revision, int num_ent)
  *	}
  */
 
+#ifndef init_freq_invariance_cppc
+static inline void init_freq_invariance_cppc(void) { }
+#endif
+
 /**
  * acpi_cppc_processor_probe - Search for per CPU _CPC objects.
  * @pr: Ptr to acpi_processor containing this CPU's logical ID.
@@ -850,6 +855,8 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
 		goto out_free;
 	}
 
+	init_freq_invariance_cppc();
+
 	kfree(output.pointer);
 	return 0;
 

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [tip: sched/core] x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC
  2020-11-12 18:26 ` [PATCH v4 2/3] x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC Giovanni Gherdovich
@ 2020-12-03  9:13   ` tip-bot2 for Giovanni Gherdovich
  2020-12-04 17:03   ` [PATCH v4 RESEND] " Giovanni Gherdovich
  2020-12-11  9:34   ` [tip: sched/core] " tip-bot2 for Giovanni Gherdovich
  2 siblings, 0 replies; 12+ messages in thread
From: tip-bot2 for Giovanni Gherdovich @ 2020-12-03  9:13 UTC (permalink / raw)
  To: linux-tip-commits; +Cc: Peter Zijlstra (Intel), x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     46609527577d1def0af29ca5b56cffeeea771ada
Gitweb:        https://git.kernel.org/tip/46609527577d1def0af29ca5b56cffeeea771ada
Author:        Giovanni Gherdovich <ggherdovich@suse.cz>
AuthorDate:    Thu, 12 Nov 2020 19:26:13 +01:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 03 Dec 2020 10:00:35 +01:00

x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC

Frequency invariant accounting calculations need the ratio
freq_curr/freq_max, but freq_max is unknown as it depends on dynamic power
allocation between cores: AMD EPYC CPUs implement "Core Performance Boost".
Three candidates are considered to estimate this value:

- maximum non-boost frequency
- maximum boost frequency
- the mid point between the above two

Experimental data on an AMD EPYC Zen2 machine slightly favors the third
option, which is applied with this patch.

The analysis uses the ondemand cpufreq governor as baseline, and compares
it with schedutil in a number of configurations. Using the freq_max value
described above offers a moderate advantage in performance and efficiency:

sugov-max (freq_max=max_boost) performs the worst on tbench: less
throughput and reduced efficiency than the other invariant-schedutil
options (see "Data Overview" below). Consider that tbench is generally a
problematic case as no schedutil version currently is better than ondemand.

sugov-P0 (freq_max=max_P) is the worst on dbench, while the other sugov's
can surpass ondemand with less filesystem latency and slightly increased
efficiency.

1. DATA OVERVIEW
2. DETAILED PERFORMANCE TABLES
3. POWER CONSUMPTION TABLE

1. DATA OVERVIEW
================

sugov-noinv : non-invariant schedutil governor
sugov-max   : invariant schedutil, freq_max=max_boost
sugov-mid   : invariant schedutil, freq_max=midpoint
sugov-P0    : invariant schedutil, freq_max=max_P
perfgov     : performance governor

driver      : acpi_cpufreq
machine     : AMD EPYC 7742 (Zen2, aka "Rome"), dual socket,
              128 cores / 256 threads, SATA SSD storage, 250G of memory,
	      XFS filesystem

Benchmarks are described in the next section.
Tilde (~) means the value is the same as baseline.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201112182614.10700-3-ggherdovich@suse.cz
---
 arch/x86/kernel/smpboot.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index a4ab5cf..c5dd5f6 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -2054,6 +2054,8 @@ static bool amd_set_max_freq_ratio(void)
 	}
 
 	perf_ratio = div_u64(highest_perf * SCHED_CAPACITY_SCALE, nominal_perf);
+	/* midpoint between max_boost and max_P */
+	perf_ratio = (perf_ratio + SCHED_CAPACITY_SCALE) >> 1;
 	if (!perf_ratio) {
 		pr_debug("Non-zero highest/nominal perf values led to a 0 ratio\n");
 		return false;

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [PATCH v4 RESEND] x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC
  2020-11-12 18:26 ` [PATCH v4 2/3] x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC Giovanni Gherdovich
  2020-12-03  9:13   ` [tip: sched/core] " tip-bot2 for Giovanni Gherdovich
@ 2020-12-04 17:03   ` Giovanni Gherdovich
  2020-12-04 17:10     ` Giovanni Gherdovich
  2020-12-11  9:34   ` [tip: sched/core] " tip-bot2 for Giovanni Gherdovich
  2 siblings, 1 reply; 12+ messages in thread
From: Giovanni Gherdovich @ 2020-12-04 17:03 UTC (permalink / raw)
  To: Borislav Petkov, Thomas Gleixner, Ingo Molnar, Peter Zijlstra,
	Len Brown, Rafael J . Wysocki
  Cc: Nathan Fontenot, x86, linux-pm, linux-kernel, linux-acpi,
	Giovanni Gherdovich

Frequency invariant accounting calculations need the ratio
freq_curr/freq_max, but freq_max is unknown as it depends on dynamic power
allocation between cores: AMD EPYC CPUs implement "Core Performance Boost".
Three candidates are considered to estimate this value:

- maximum non-boost frequency
- maximum boost frequency
- the mid point between the above two

Experimental data on an AMD EPYC Zen2 machine slightly favors the third
option, which is applied with this patch.

The analysis uses the ondemand cpufreq governor as baseline, and compares
it with schedutil in a number of configurations. Using the freq_max value
described above offers a moderate advantage in performance and efficiency:

sugov-max (freq_max=max_boost) performs the worst on tbench: less
throughput and reduced efficiency than the other invariant-schedutil
options (see "Data Overview" below). Consider that tbench is generally a
problematic case as no schedutil version currently is better than ondemand.

sugov-P0 (freq_max=max_P) is the worst on dbench, while the other sugov's
can surpass ondemand with less filesystem latency and slightly increased
efficiency.

1. DATA OVERVIEW
2. DETAILED PERFORMANCE TABLES
3. POWER CONSUMPTION TABLE

1. DATA OVERVIEW
================

sugov-noinv : non-invariant schedutil governor
sugov-max   : invariant schedutil, freq_max=max_boost
sugov-mid   : invariant schedutil, freq_max=midpoint
sugov-P0    : invariant schedutil, freq_max=max_P
perfgov     : performance governor

driver      : acpi_cpufreq
machine     : AMD EPYC 7742 (Zen2, aka "Rome"), dual socket,
              128 cores / 256 threads, SATA SSD storage, 250G of memory,
	      XFS filesystem

Benchmarks are described in the next section.
Tilde (~) means the value is the same as baseline.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
            ondemand  perfgov  sugov-noinv  sugov-max  sugov-mid  sugov-P0  better if
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
                                        PERFORMANCE RATIOS
tbench        1.00       1.44       0.90       0.87       0.93       0.93      higher
dbench        1.00       0.91       0.95       0.94       0.94       1.06      lower
kernbench     1.00       0.93       ~          ~          ~          0.97      lower
gitsource     1.00       0.66       0.97       0.96       ~          0.95      lower
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
                                    PERFORMANCE-PER-WATT RATIOS
tbench        1.00       1.16       0.84       0.84       0.88       0.85      higher
dbench        1.00       1.03       1.02       1.02       1.02       0.93      higher
kernbench     1.00       1.05       ~          ~          ~          ~         higher
gitsource     1.00       1.46       1.04       1.04       ~          1.05      higher

2. DETAILED PERFORMANCE TABLES
==============================

Benchmark          : tbench4 (i.e. dbench4 over the network, actually loopback)
Varying parameter  : number of clients
Unit               : MB/sec (higher is better)

                  5.9.0-ondemand (BASELINE)                   5.9.0-perfgov               5.9.0-sugov-noinv
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Hmean  1        427.19  +- 0.16% (        )     778.35  +- 0.10% (  82.20%)     346.92  +- 0.14% ( -18.79%)
Hmean  2        853.82  +- 0.09% (        )    1536.23  +- 0.03% (  79.93%)     694.36  +- 0.05% ( -18.68%)
Hmean  4       1657.54  +- 0.12% (        )    2938.18  +- 0.12% (  77.26%)    1362.81  +- 0.11% ( -17.78%)
Hmean  8       3301.87  +- 0.06% (        )    5679.10  +- 0.04% (  72.00%)    2693.35  +- 0.04% ( -18.43%)
Hmean  16      6139.65  +- 0.05% (        )    9498.81  +- 0.04% (  54.71%)    4889.97  +- 0.17% ( -20.35%)
Hmean  32     11170.28  +- 0.09% (        )   17393.25  +- 0.08% (  55.71%)    9104.55  +- 0.09% ( -18.49%)
Hmean  64     19322.97  +- 0.17% (        )   31573.91  +- 0.08% (  63.40%)   18552.52  +- 0.40% (  -3.99%)
Hmean  128    30383.71  +- 0.11% (        )   37416.91  +- 0.15% (  23.15%)   25938.70  +- 0.41% ( -14.63%)
Hmean  256    31143.96  +- 0.41% (        )   30908.76  +- 0.88% (  -0.76%)   29754.32  +- 0.24% (  -4.46%)
Hmean  512    30858.49  +- 0.26% (        )   38524.60  +- 1.19% (  24.84%)   42080.39  +- 0.56% (  36.37%)
Hmean  1024   39187.37  +- 0.19% (        )   36213.86  +- 0.26% (  -7.59%)   39555.98  +- 0.12% (   0.94%)

                            5.9.0-sugov-max                 5.9.0-sugov-mid                  5.9.0-sugov-P0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Hmean  1        352.59  +- 1.03% ( -17.46%)     352.08  +- 0.75% ( -17.58%)     352.31  +- 1.48% ( -17.53%)
Hmean  2        697.32  +- 0.08% ( -18.33%)     700.16  +- 0.20% ( -18.00%)     696.79  +- 0.06% ( -18.39%)
Hmean  4       1369.88  +- 0.04% ( -17.35%)    1369.72  +- 0.07% ( -17.36%)    1365.91  +- 0.05% ( -17.59%)
Hmean  8       2696.79  +- 0.04% ( -18.33%)    2711.06  +- 0.04% ( -17.89%)    2715.10  +- 0.61% ( -17.77%)
Hmean  16      4725.03  +- 0.03% ( -23.04%)    4875.65  +- 0.02% ( -20.59%)    4953.05  +- 0.28% ( -19.33%)
Hmean  32      9231.65  +- 0.10% ( -17.36%)    8704.89  +- 0.27% ( -22.07%)   10562.02  +- 0.36% (  -5.45%)
Hmean  64     15364.27  +- 0.19% ( -20.49%)   17786.64  +- 0.15% (  -7.95%)   19665.40  +- 0.22% (   1.77%)
Hmean  128    42100.58  +- 0.13% (  38.56%)   34946.28  +- 0.13% (  15.02%)   38635.79  +- 0.06% (  27.16%)
Hmean  256    30660.23  +- 1.08% (  -1.55%)   32307.67  +- 0.54% (   3.74%)   31153.27  +- 0.12% (   0.03%)
Hmean  512    24604.32  +- 0.14% ( -20.27%)   40408.50  +- 1.10% (  30.95%)   38800.29  +- 1.23% (  25.74%)
Hmean  1024   35535.47  +- 0.28% (  -9.32%)   41070.38  +- 2.56% (   4.81%)   31308.29  +- 2.52% ( -20.11%)

Benchmark          : dbench (filesystem stressor)
Varying parameter  : number of clients
Unit               : seconds (lower is better)

NOTE-1: This dbench version measures the average latency of a set of filesystem
        operations, as we found the traditional dbench metric (throughput) to be
	misleading.
NOTE-2: Due to high variability, we partition the original dataset and apply
        statistical bootrapping (a resampling method). Accuracy is reported in the
	form of 95% confidence intervals.

                  5.9.0-ondemand (BASELINE)                   5.9.0-perfgov               5.9.0-sugov-noinv
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
SubAmean  1         98.79  +- 0.92 (        )      83.36  +- 0.82 (  15.62%)      84.82  +- 0.92 (  14.14%)
SubAmean  2        116.00  +- 0.89 (        )     102.12  +- 0.77 (  11.96%)     109.63  +- 0.89 (   5.49%)
SubAmean  4        149.90  +- 1.03 (        )     132.12  +- 0.91 (  11.86%)     143.90  +- 1.15 (   4.00%)
SubAmean  8        182.41  +- 1.13 (        )     159.86  +- 0.93 (  12.36%)     165.82  +- 1.03 (   9.10%)
SubAmean  16       237.83  +- 1.23 (        )     219.46  +- 1.14 (   7.72%)     229.28  +- 1.19 (   3.59%)
SubAmean  32       334.34  +- 1.49 (        )     309.94  +- 1.42 (   7.30%)     321.19  +- 1.36 (   3.93%)
SubAmean  64       576.61  +- 2.16 (        )     540.75  +- 2.00 (   6.22%)     551.27  +- 1.99 (   4.39%)
SubAmean  128     1350.07  +- 4.14 (        )    1205.47  +- 3.20 (  10.71%)    1280.26  +- 3.75 (   5.17%)
SubAmean  256     3444.42  +- 7.97 (        )    3698.00 +- 27.43 (  -7.36%)    3494.14  +- 7.81 (  -1.44%)
SubAmean  2048   39457.89 +- 29.01 (        )   34105.33 +- 41.85 (  13.57%)   39688.52 +- 36.26 (  -0.58%)

                            5.9.0-sugov-max                 5.9.0-sugov-mid                  5.9.0-sugov-P0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
SubAmean  1         85.68  +- 1.04 (  13.27%)      84.16  +- 0.84 (  14.81%)      83.99  +- 0.90 (  14.99%)
SubAmean  2        108.42  +- 0.95 (   6.54%)     109.91  +- 1.39 (   5.24%)     112.06  +- 0.91 (   3.39%)
SubAmean  4        136.90  +- 1.04 (   8.67%)     137.59  +- 0.93 (   8.21%)     136.55  +- 0.95 (   8.91%)
SubAmean  8        163.15  +- 0.96 (  10.56%)     166.07  +- 1.02 (   8.96%)     165.81  +- 0.99 (   9.10%)
SubAmean  16       224.86  +- 1.12 (   5.45%)     223.83  +- 1.06 (   5.89%)     230.66  +- 1.19 (   3.01%)
SubAmean  32       320.51  +- 1.38 (   4.13%)     322.85  +- 1.49 (   3.44%)     321.96  +- 1.46 (   3.70%)
SubAmean  64       553.25  +- 1.93 (   4.05%)     554.19  +- 2.08 (   3.89%)     562.26  +- 2.22 (   2.49%)
SubAmean  128     1264.35  +- 3.72 (   6.35%)    1256.99  +- 3.46 (   6.89%)    2018.97 +- 18.79 ( -49.55%)
SubAmean  256     3466.25  +- 8.25 (  -0.63%)    3450.58  +- 8.44 (  -0.18%)    5032.12 +- 38.74 ( -46.09%)
SubAmean  2048   39133.10 +- 45.71 (   0.82%)   39905.95 +- 34.33 (  -1.14%)   53811.86 +-193.04 ( -36.38%)

Benchmark          : kernbench (kernel compilation)
Varying parameter  : number of jobs
Unit               : seconds (lower is better)

                  5.9.0-ondemand (BASELINE)                   5.9.0-perfgov               5.9.0-sugov-noinv
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean  2        471.71 +- 26.61% (        )     409.88 +- 16.99% (  13.11%)     430.63  +- 0.18% (   8.71%)
Amean  4        211.87  +- 0.58% (        )     194.03  +- 0.74% (   8.42%)     215.33  +- 0.64% (  -1.63%)
Amean  8        109.79  +- 1.27% (        )     101.43  +- 1.53% (   7.61%)     111.05  +- 1.95% (  -1.15%)
Amean  16        59.50  +- 1.28% (        )      55.61  +- 1.35% (   6.55%)      59.65  +- 1.78% (  -0.24%)
Amean  32        34.94  +- 1.22% (        )      32.36  +- 1.95% (   7.41%)      35.44  +- 0.63% (  -1.43%)
Amean  64        22.58  +- 0.38% (        )      20.97  +- 1.28% (   7.11%)      22.41  +- 1.73% (   0.74%)
Amean  128       17.72  +- 0.44% (        )      16.68  +- 0.32% (   5.88%)      17.65  +- 0.96% (   0.37%)
Amean  256       16.44  +- 0.53% (        )      15.76  +- 0.32% (   4.18%)      16.76  +- 0.60% (  -1.93%)
Amean  512       16.54  +- 0.21% (        )      15.62  +- 0.41% (   5.53%)      16.84  +- 0.85% (  -1.83%)

                            5.9.0-sugov-max                 5.9.0-sugov-mid                  5.9.0-sugov-P0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean  2        421.30  +- 0.24% (  10.69%)     419.26  +- 0.15% (  11.12%)     414.38  +- 0.33% (  12.15%)
Amean  4  	217.81  +- 5.53% (  -2.80%)     211.63  +- 0.99% (   0.12%)     208.43  +- 0.47% (   1.63%)
Amean  8  	108.80  +- 0.43% (   0.90%)     108.48  +- 1.44% (   1.19%)     108.59  +- 3.08% (   1.09%)
Amean  16 	 58.84  +- 0.74% (   1.12%)      58.37  +- 0.94% (   1.91%)      57.78  +- 0.78% (   2.90%)
Amean  32 	 34.04  +- 2.00% (   2.59%)      34.28  +- 1.18% (   1.91%)      33.98  +- 2.21% (   2.75%)
Amean  64 	 22.22  +- 1.69% (   1.60%)      22.27  +- 1.60% (   1.38%)      22.25  +- 1.41% (   1.47%)
Amean  128	 17.55  +- 0.24% (   0.97%)      17.53  +- 0.94% (   1.04%)      17.49  +- 0.43% (   1.30%)
Amean  256	 16.51  +- 0.46% (  -0.40%)      16.48  +- 0.48% (  -0.19%)      16.44  +- 1.21% (   0.00%)
Amean  512	 16.50  +- 0.35% (   0.19%)      16.35  +- 0.42% (   1.14%)      16.37  +- 0.33% (   0.99%)

Benchmark          : gitsource (time to run the git unit test suite)
Varying parameter  : none
Unit               : seconds (lower is better)

                  5.9.0-ondemand (BASELINE)                   5.9.0-perfgov               5.9.0-sugov-noinv
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean          1035.76  +- 0.30% (        )     688.21  +- 0.04% (  33.56%)    1003.85  +- 0.14% (   3.08%)

                            5.9.0-sugov-max                 5.9.0-sugov-mid                  5.9.0-sugov-P0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean           995.82  +- 0.08% (   3.86%)    1011.98  +- 0.03% (   2.30%)     986.87  +- 0.19% (   4.72%)

3. POWER CONSUMPTION TABLE
==========================

Average power consumption (watts).

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
            ondemand  perfgov  sugov-noinv  sugov-max  sugov-mid  sugov-P0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
tbench4     227.25     281.83     244.17     236.76     241.50     247.99
dbench4     151.97     161.87     157.08     158.10     158.06     153.73
kernbench   162.78     167.22     162.90     164.19     164.65     164.72
gitsource   133.65     139.00     133.04     134.43     134.18     134.32

Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201112182614.10700-3-ggherdovich@suse.cz
---
 arch/x86/kernel/smpboot.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index a4ab5cf6aeab..c5dd5f6199d9 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -2054,6 +2054,8 @@ static bool amd_set_max_freq_ratio(void)
 	}
 
 	perf_ratio = div_u64(highest_perf * SCHED_CAPACITY_SCALE, nominal_perf);
+	/* midpoint between max_boost and max_P */
+	perf_ratio = (perf_ratio + SCHED_CAPACITY_SCALE) >> 1;
 	if (!perf_ratio) {
 		pr_debug("Non-zero highest/nominal perf values led to a 0 ratio\n");
 		return false;
-- 
2.26.2


^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v4 RESEND] x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC
  2020-12-04 17:03   ` [PATCH v4 RESEND] " Giovanni Gherdovich
@ 2020-12-04 17:10     ` Giovanni Gherdovich
  0 siblings, 0 replies; 12+ messages in thread
From: Giovanni Gherdovich @ 2020-12-04 17:10 UTC (permalink / raw)
  To: Borislav Petkov, Thomas Gleixner, Ingo Molnar, Peter Zijlstra,
	Len Brown, Rafael J . Wysocki
  Cc: Nathan Fontenot, x86, linux-pm, linux-kernel, linux-acpi

On Fri, 2020-12-04 at 18:03 +0100, Giovanni Gherdovich wrote:
> Frequency invariant accounting calculations need the ratio
> freq_curr/freq_max, but freq_max is unknown as it depends on dynamic power
> allocation between cores: AMD EPYC CPUs implement "Core Performance Boost".
> Three candidates are considered to estimate this value:
> [...]
> 
> Benchmarks are described in the next section.
> Tilde (~) means the value is the same as baseline.
> 
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
>             ondemand  perfgov  sugov-noinv  sugov-max  sugov-mid  sugov-P0  better if
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
> [...]

Hello,

this patch is currently merged in the tip tree, branch sched/core as
commit 46609527577d1def0af29ca5b56cffeeea771ada.

Unfortunately in the original commit message I used "----------" for
making table headers, and git dropped all the commit message after
that sign, i.e. the benchmark results and my signed-off-by.

In this "resend" I replaced the offending sign and the new commit
message should make it intact to the destination tree.


Thanks,
Giovanni




^ permalink raw reply	[flat|nested] 12+ messages in thread

* [tip: sched/core] x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC
  2020-11-12 18:26 ` [PATCH v4 2/3] x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC Giovanni Gherdovich
  2020-12-03  9:13   ` [tip: sched/core] " tip-bot2 for Giovanni Gherdovich
  2020-12-04 17:03   ` [PATCH v4 RESEND] " Giovanni Gherdovich
@ 2020-12-11  9:34   ` tip-bot2 for Giovanni Gherdovich
  2 siblings, 0 replies; 12+ messages in thread
From: tip-bot2 for Giovanni Gherdovich @ 2020-12-11  9:34 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Giovanni Gherdovich, Peter Zijlstra (Intel),
	Ingo Molnar, x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     976df7e5730e3ec8a7e192c09c10ce6e8db07e65
Gitweb:        https://git.kernel.org/tip/976df7e5730e3ec8a7e192c09c10ce6e8db07e65
Author:        Giovanni Gherdovich <ggherdovich@suse.cz>
AuthorDate:    Thu, 12 Nov 2020 19:26:13 +01:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 11 Dec 2020 10:29:55 +01:00

x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC

Frequency invariant accounting calculations need the ratio
freq_curr/freq_max, but freq_max is unknown as it depends on dynamic power
allocation between cores: AMD EPYC CPUs implement "Core Performance Boost".
Three candidates are considered to estimate this value:

- maximum non-boost frequency
- maximum boost frequency
- the mid point between the above two

Experimental data on an AMD EPYC Zen2 machine slightly favors the third
option, which is applied with this patch.

The analysis uses the ondemand cpufreq governor as baseline, and compares
it with schedutil in a number of configurations. Using the freq_max value
described above offers a moderate advantage in performance and efficiency:

sugov-max (freq_max=max_boost) performs the worst on tbench: less
throughput and reduced efficiency than the other invariant-schedutil
options (see "Data Overview" below). Consider that tbench is generally a
problematic case as no schedutil version currently is better than ondemand.

sugov-P0 (freq_max=max_P) is the worst on dbench, while the other sugov's
can surpass ondemand with less filesystem latency and slightly increased
efficiency.

1. DATA OVERVIEW
2. DETAILED PERFORMANCE TABLES
3. POWER CONSUMPTION TABLE

1. DATA OVERVIEW
================

sugov-noinv : non-invariant schedutil governor
sugov-max   : invariant schedutil, freq_max=max_boost
sugov-mid   : invariant schedutil, freq_max=midpoint
sugov-P0    : invariant schedutil, freq_max=max_P
perfgov     : performance governor

driver      : acpi_cpufreq
machine     : AMD EPYC 7742 (Zen2, aka "Rome"), dual socket,
              128 cores / 256 threads, SATA SSD storage, 250G of memory,
	      XFS filesystem

Benchmarks are described in the next section.
Tilde (~) means the value is the same as baseline.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
            ondemand  perfgov  sugov-noinv  sugov-max  sugov-mid  sugov-P0  better if
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
                                        PERFORMANCE RATIOS
tbench        1.00       1.44       0.90       0.87       0.93       0.93      higher
dbench        1.00       0.91       0.95       0.94       0.94       1.06      lower
kernbench     1.00       0.93       ~          ~          ~          0.97      lower
gitsource     1.00       0.66       0.97       0.96       ~          0.95      lower
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
                                    PERFORMANCE-PER-WATT RATIOS
tbench        1.00       1.16       0.84       0.84       0.88       0.85      higher
dbench        1.00       1.03       1.02       1.02       1.02       0.93      higher
kernbench     1.00       1.05       ~          ~          ~          ~         higher
gitsource     1.00       1.46       1.04       1.04       ~          1.05      higher

2. DETAILED PERFORMANCE TABLES
==============================

Benchmark          : tbench4 (i.e. dbench4 over the network, actually loopback)
Varying parameter  : number of clients
Unit               : MB/sec (higher is better)

                  5.9.0-ondemand (BASELINE)                   5.9.0-perfgov               5.9.0-sugov-noinv
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Hmean  1        427.19  +- 0.16% (        )     778.35  +- 0.10% (  82.20%)     346.92  +- 0.14% ( -18.79%)
Hmean  2        853.82  +- 0.09% (        )    1536.23  +- 0.03% (  79.93%)     694.36  +- 0.05% ( -18.68%)
Hmean  4       1657.54  +- 0.12% (        )    2938.18  +- 0.12% (  77.26%)    1362.81  +- 0.11% ( -17.78%)
Hmean  8       3301.87  +- 0.06% (        )    5679.10  +- 0.04% (  72.00%)    2693.35  +- 0.04% ( -18.43%)
Hmean  16      6139.65  +- 0.05% (        )    9498.81  +- 0.04% (  54.71%)    4889.97  +- 0.17% ( -20.35%)
Hmean  32     11170.28  +- 0.09% (        )   17393.25  +- 0.08% (  55.71%)    9104.55  +- 0.09% ( -18.49%)
Hmean  64     19322.97  +- 0.17% (        )   31573.91  +- 0.08% (  63.40%)   18552.52  +- 0.40% (  -3.99%)
Hmean  128    30383.71  +- 0.11% (        )   37416.91  +- 0.15% (  23.15%)   25938.70  +- 0.41% ( -14.63%)
Hmean  256    31143.96  +- 0.41% (        )   30908.76  +- 0.88% (  -0.76%)   29754.32  +- 0.24% (  -4.46%)
Hmean  512    30858.49  +- 0.26% (        )   38524.60  +- 1.19% (  24.84%)   42080.39  +- 0.56% (  36.37%)
Hmean  1024   39187.37  +- 0.19% (        )   36213.86  +- 0.26% (  -7.59%)   39555.98  +- 0.12% (   0.94%)

                            5.9.0-sugov-max                 5.9.0-sugov-mid                  5.9.0-sugov-P0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Hmean  1        352.59  +- 1.03% ( -17.46%)     352.08  +- 0.75% ( -17.58%)     352.31  +- 1.48% ( -17.53%)
Hmean  2        697.32  +- 0.08% ( -18.33%)     700.16  +- 0.20% ( -18.00%)     696.79  +- 0.06% ( -18.39%)
Hmean  4       1369.88  +- 0.04% ( -17.35%)    1369.72  +- 0.07% ( -17.36%)    1365.91  +- 0.05% ( -17.59%)
Hmean  8       2696.79  +- 0.04% ( -18.33%)    2711.06  +- 0.04% ( -17.89%)    2715.10  +- 0.61% ( -17.77%)
Hmean  16      4725.03  +- 0.03% ( -23.04%)    4875.65  +- 0.02% ( -20.59%)    4953.05  +- 0.28% ( -19.33%)
Hmean  32      9231.65  +- 0.10% ( -17.36%)    8704.89  +- 0.27% ( -22.07%)   10562.02  +- 0.36% (  -5.45%)
Hmean  64     15364.27  +- 0.19% ( -20.49%)   17786.64  +- 0.15% (  -7.95%)   19665.40  +- 0.22% (   1.77%)
Hmean  128    42100.58  +- 0.13% (  38.56%)   34946.28  +- 0.13% (  15.02%)   38635.79  +- 0.06% (  27.16%)
Hmean  256    30660.23  +- 1.08% (  -1.55%)   32307.67  +- 0.54% (   3.74%)   31153.27  +- 0.12% (   0.03%)
Hmean  512    24604.32  +- 0.14% ( -20.27%)   40408.50  +- 1.10% (  30.95%)   38800.29  +- 1.23% (  25.74%)
Hmean  1024   35535.47  +- 0.28% (  -9.32%)   41070.38  +- 2.56% (   4.81%)   31308.29  +- 2.52% ( -20.11%)

Benchmark          : dbench (filesystem stressor)
Varying parameter  : number of clients
Unit               : seconds (lower is better)

NOTE-1: This dbench version measures the average latency of a set of filesystem
        operations, as we found the traditional dbench metric (throughput) to be
	misleading.
NOTE-2: Due to high variability, we partition the original dataset and apply
        statistical bootrapping (a resampling method). Accuracy is reported in the
	form of 95% confidence intervals.

                  5.9.0-ondemand (BASELINE)                   5.9.0-perfgov               5.9.0-sugov-noinv
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
SubAmean  1         98.79  +- 0.92 (        )      83.36  +- 0.82 (  15.62%)      84.82  +- 0.92 (  14.14%)
SubAmean  2        116.00  +- 0.89 (        )     102.12  +- 0.77 (  11.96%)     109.63  +- 0.89 (   5.49%)
SubAmean  4        149.90  +- 1.03 (        )     132.12  +- 0.91 (  11.86%)     143.90  +- 1.15 (   4.00%)
SubAmean  8        182.41  +- 1.13 (        )     159.86  +- 0.93 (  12.36%)     165.82  +- 1.03 (   9.10%)
SubAmean  16       237.83  +- 1.23 (        )     219.46  +- 1.14 (   7.72%)     229.28  +- 1.19 (   3.59%)
SubAmean  32       334.34  +- 1.49 (        )     309.94  +- 1.42 (   7.30%)     321.19  +- 1.36 (   3.93%)
SubAmean  64       576.61  +- 2.16 (        )     540.75  +- 2.00 (   6.22%)     551.27  +- 1.99 (   4.39%)
SubAmean  128     1350.07  +- 4.14 (        )    1205.47  +- 3.20 (  10.71%)    1280.26  +- 3.75 (   5.17%)
SubAmean  256     3444.42  +- 7.97 (        )    3698.00 +- 27.43 (  -7.36%)    3494.14  +- 7.81 (  -1.44%)
SubAmean  2048   39457.89 +- 29.01 (        )   34105.33 +- 41.85 (  13.57%)   39688.52 +- 36.26 (  -0.58%)

                            5.9.0-sugov-max                 5.9.0-sugov-mid                  5.9.0-sugov-P0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
SubAmean  1         85.68  +- 1.04 (  13.27%)      84.16  +- 0.84 (  14.81%)      83.99  +- 0.90 (  14.99%)
SubAmean  2        108.42  +- 0.95 (   6.54%)     109.91  +- 1.39 (   5.24%)     112.06  +- 0.91 (   3.39%)
SubAmean  4        136.90  +- 1.04 (   8.67%)     137.59  +- 0.93 (   8.21%)     136.55  +- 0.95 (   8.91%)
SubAmean  8        163.15  +- 0.96 (  10.56%)     166.07  +- 1.02 (   8.96%)     165.81  +- 0.99 (   9.10%)
SubAmean  16       224.86  +- 1.12 (   5.45%)     223.83  +- 1.06 (   5.89%)     230.66  +- 1.19 (   3.01%)
SubAmean  32       320.51  +- 1.38 (   4.13%)     322.85  +- 1.49 (   3.44%)     321.96  +- 1.46 (   3.70%)
SubAmean  64       553.25  +- 1.93 (   4.05%)     554.19  +- 2.08 (   3.89%)     562.26  +- 2.22 (   2.49%)
SubAmean  128     1264.35  +- 3.72 (   6.35%)    1256.99  +- 3.46 (   6.89%)    2018.97 +- 18.79 ( -49.55%)
SubAmean  256     3466.25  +- 8.25 (  -0.63%)    3450.58  +- 8.44 (  -0.18%)    5032.12 +- 38.74 ( -46.09%)
SubAmean  2048   39133.10 +- 45.71 (   0.82%)   39905.95 +- 34.33 (  -1.14%)   53811.86 +-193.04 ( -36.38%)

Benchmark          : kernbench (kernel compilation)
Varying parameter  : number of jobs
Unit               : seconds (lower is better)

                  5.9.0-ondemand (BASELINE)                   5.9.0-perfgov               5.9.0-sugov-noinv
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean  2        471.71 +- 26.61% (        )     409.88 +- 16.99% (  13.11%)     430.63  +- 0.18% (   8.71%)
Amean  4        211.87  +- 0.58% (        )     194.03  +- 0.74% (   8.42%)     215.33  +- 0.64% (  -1.63%)
Amean  8        109.79  +- 1.27% (        )     101.43  +- 1.53% (   7.61%)     111.05  +- 1.95% (  -1.15%)
Amean  16        59.50  +- 1.28% (        )      55.61  +- 1.35% (   6.55%)      59.65  +- 1.78% (  -0.24%)
Amean  32        34.94  +- 1.22% (        )      32.36  +- 1.95% (   7.41%)      35.44  +- 0.63% (  -1.43%)
Amean  64        22.58  +- 0.38% (        )      20.97  +- 1.28% (   7.11%)      22.41  +- 1.73% (   0.74%)
Amean  128       17.72  +- 0.44% (        )      16.68  +- 0.32% (   5.88%)      17.65  +- 0.96% (   0.37%)
Amean  256       16.44  +- 0.53% (        )      15.76  +- 0.32% (   4.18%)      16.76  +- 0.60% (  -1.93%)
Amean  512       16.54  +- 0.21% (        )      15.62  +- 0.41% (   5.53%)      16.84  +- 0.85% (  -1.83%)

                            5.9.0-sugov-max                 5.9.0-sugov-mid                  5.9.0-sugov-P0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean  2        421.30  +- 0.24% (  10.69%)     419.26  +- 0.15% (  11.12%)     414.38  +- 0.33% (  12.15%)
Amean  4  	217.81  +- 5.53% (  -2.80%)     211.63  +- 0.99% (   0.12%)     208.43  +- 0.47% (   1.63%)
Amean  8  	108.80  +- 0.43% (   0.90%)     108.48  +- 1.44% (   1.19%)     108.59  +- 3.08% (   1.09%)
Amean  16 	 58.84  +- 0.74% (   1.12%)      58.37  +- 0.94% (   1.91%)      57.78  +- 0.78% (   2.90%)
Amean  32 	 34.04  +- 2.00% (   2.59%)      34.28  +- 1.18% (   1.91%)      33.98  +- 2.21% (   2.75%)
Amean  64 	 22.22  +- 1.69% (   1.60%)      22.27  +- 1.60% (   1.38%)      22.25  +- 1.41% (   1.47%)
Amean  128	 17.55  +- 0.24% (   0.97%)      17.53  +- 0.94% (   1.04%)      17.49  +- 0.43% (   1.30%)
Amean  256	 16.51  +- 0.46% (  -0.40%)      16.48  +- 0.48% (  -0.19%)      16.44  +- 1.21% (   0.00%)
Amean  512	 16.50  +- 0.35% (   0.19%)      16.35  +- 0.42% (   1.14%)      16.37  +- 0.33% (   0.99%)

Benchmark          : gitsource (time to run the git unit test suite)
Varying parameter  : none
Unit               : seconds (lower is better)

                  5.9.0-ondemand (BASELINE)                   5.9.0-perfgov               5.9.0-sugov-noinv
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean          1035.76  +- 0.30% (        )     688.21  +- 0.04% (  33.56%)    1003.85  +- 0.14% (   3.08%)

                            5.9.0-sugov-max                 5.9.0-sugov-mid                  5.9.0-sugov-P0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean           995.82  +- 0.08% (   3.86%)    1011.98  +- 0.03% (   2.30%)     986.87  +- 0.19% (   4.72%)

3. POWER CONSUMPTION TABLE
==========================

Average power consumption (watts).

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
            ondemand  perfgov  sugov-noinv  sugov-max  sugov-mid  sugov-P0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
tbench4     227.25     281.83     244.17     236.76     241.50     247.99
dbench4     151.97     161.87     157.08     158.10     158.06     153.73
kernbench   162.78     167.22     162.90     164.19     164.65     164.72
gitsource   133.65     139.00     133.04     134.43     134.18     134.32

Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20201112182614.10700-3-ggherdovich@suse.cz
---
 arch/x86/kernel/smpboot.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index a4ab5cf..c5dd5f6 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -2054,6 +2054,8 @@ static bool amd_set_max_freq_ratio(void)
 	}
 
 	perf_ratio = div_u64(highest_perf * SCHED_CAPACITY_SCALE, nominal_perf);
+	/* midpoint between max_boost and max_P */
+	perf_ratio = (perf_ratio + SCHED_CAPACITY_SCALE) >> 1;
 	if (!perf_ratio) {
 		pr_debug("Non-zero highest/nominal perf values led to a 0 ratio\n");
 		return false;

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [tip: sched/core] x86: Print ratio freq_max/freq_base used in frequency invariance calculations
  2020-11-12 18:26 ` [PATCH v4 3/3] x86: Print ratio freq_max/freq_base used in frequency invariance calculations Giovanni Gherdovich
  2020-12-03  9:13   ` [tip: sched/core] " tip-bot2 for Giovanni Gherdovich
@ 2020-12-11  9:34   ` tip-bot2 for Giovanni Gherdovich
  1 sibling, 0 replies; 12+ messages in thread
From: tip-bot2 for Giovanni Gherdovich @ 2020-12-11  9:34 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Giovanni Gherdovich, Peter Zijlstra (Intel),
	Ingo Molnar, x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     3149cd55302748df771dc1c8c10f34b1cbce88ed
Gitweb:        https://git.kernel.org/tip/3149cd55302748df771dc1c8c10f34b1cbce88ed
Author:        Giovanni Gherdovich <ggherdovich@suse.cz>
AuthorDate:    Thu, 12 Nov 2020 19:26:14 +01:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 11 Dec 2020 10:30:23 +01:00

x86: Print ratio freq_max/freq_base used in frequency invariance calculations

The value freq_max/freq_base is a fundamental component of frequency
invariance calculations. It may come from a variety of sources such as MSRs
or ACPI data, tracking it down when troubleshooting a system could be
non-trivial. It is worth saving it in the kernel logs.

 # dmesg | grep 'Estimated ratio of average max'
 [   14.024036] smpboot: Estimated ratio of average max frequency by base frequency (times 1024): 1289

Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20201112182614.10700-4-ggherdovich@suse.cz
---
 arch/x86/kernel/smpboot.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index c5dd5f6..3577bb7 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -2110,6 +2110,7 @@ static void init_freq_invariance(bool secondary, bool cppc_ready)
 	if (ret) {
 		init_counter_refs();
 		static_branch_enable(&arch_scale_freq_key);
+		pr_info("Estimated ratio of average max frequency by base frequency (times 1024): %llu\n", arch_max_freq_ratio);
 	} else {
 		pr_debug("Couldn't determine max cpu frequency, necessary for scale-invariant accounting.\n");
 	}

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [tip: sched/core] x86, sched: Calculate frequency invariance for AMD systems
  2020-11-12 18:26 ` [PATCH v4 1/3] x86, sched: Calculate frequency invariance for AMD systems Giovanni Gherdovich
  2020-12-03  9:13   ` [tip: sched/core] " tip-bot2 for Nathan Fontenot
@ 2020-12-11  9:34   ` tip-bot2 for Nathan Fontenot
  1 sibling, 0 replies; 12+ messages in thread
From: tip-bot2 for Nathan Fontenot @ 2020-12-11  9:34 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Nathan Fontenot, Giovanni Gherdovich, Peter Zijlstra (Intel),
	Ingo Molnar, x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     41ea667227bad5c247d76e6605054e96e4d95f51
Gitweb:        https://git.kernel.org/tip/41ea667227bad5c247d76e6605054e96e4d95f51
Author:        Nathan Fontenot <nathan.fontenot@amd.com>
AuthorDate:    Thu, 12 Nov 2020 19:26:12 +01:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 11 Dec 2020 10:26:00 +01:00

x86, sched: Calculate frequency invariance for AMD systems

This is the first pass in creating the ability to calculate the
frequency invariance on AMD systems. This approach uses the CPPC
highest performance and nominal performance values that range from
0 - 255 instead of a high and base frquency. This is because we do
not have the ability on AMD to get a highest frequency value.

On AMD systems the highest performance and nominal performance
vaues do correspond to the highest and base frequencies for the system
so using them should produce an appropriate ratio but some tweaking
is likely necessary.

Due to CPPC being initialized later in boot than when the frequency
invariant calculation is currently made, I had to create a callback
from the CPPC init code to do the calculation after we have CPPC
data.

Special thanks to "kernel test robot <lkp@intel.com>" for reporting that
compilation of drivers/acpi/cppc_acpi.c is conditional to
CONFIG_ACPI_CPPC_LIB, not just CONFIG_ACPI.

[ ggherdovich@suse.cz: made safe under CPU hotplug, edited changelog. ]

Signed-off-by: Nathan Fontenot <nathan.fontenot@amd.com>
Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20201112182614.10700-2-ggherdovich@suse.cz
---
 arch/x86/include/asm/topology.h |  5 ++-
 arch/x86/kernel/smpboot.c       | 76 +++++++++++++++++++++++++++++---
 drivers/acpi/cppc_acpi.c        |  7 +++-
 3 files changed, 83 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index f423457..488a8e8 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -218,4 +218,9 @@ static inline void arch_set_max_freq_ratio(bool turbo_disabled)
 }
 #endif
 
+#ifdef CONFIG_ACPI_CPPC_LIB
+void init_freq_invariance_cppc(void);
+#define init_freq_invariance_cppc init_freq_invariance_cppc
+#endif
+
 #endif /* _ASM_X86_TOPOLOGY_H */
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index de776b2..a4ab5cf 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -82,6 +82,10 @@
 #include <asm/hw_irq.h>
 #include <asm/stackprotector.h>
 
+#ifdef CONFIG_ACPI_CPPC_LIB
+#include <acpi/cppc_acpi.h>
+#endif
+
 /* representing HT siblings of each logical CPU */
 DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map);
 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
@@ -148,7 +152,7 @@ static inline void smpboot_restore_warm_reset_vector(void)
 	*((volatile u32 *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = 0;
 }
 
-static void init_freq_invariance(bool secondary);
+static void init_freq_invariance(bool secondary, bool cppc_ready);
 
 /*
  * Report back to the Boot Processor during boot time or to the caller processor
@@ -186,7 +190,7 @@ static void smp_callin(void)
 	 */
 	set_cpu_sibling_map(raw_smp_processor_id());
 
-	init_freq_invariance(true);
+	init_freq_invariance(true, false);
 
 	/*
 	 * Get our bogomips.
@@ -1340,7 +1344,7 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
 	set_sched_topology(x86_topology);
 
 	set_cpu_sibling_map(0);
-	init_freq_invariance(false);
+	init_freq_invariance(false, false);
 	smp_sanity_check();
 
 	switch (apic_intr_mode) {
@@ -2027,6 +2031,46 @@ out:
 	return true;
 }
 
+#ifdef CONFIG_ACPI_CPPC_LIB
+static bool amd_set_max_freq_ratio(void)
+{
+	struct cppc_perf_caps perf_caps;
+	u64 highest_perf, nominal_perf;
+	u64 perf_ratio;
+	int rc;
+
+	rc = cppc_get_perf_caps(0, &perf_caps);
+	if (rc) {
+		pr_debug("Could not retrieve perf counters (%d)\n", rc);
+		return false;
+	}
+
+	highest_perf = perf_caps.highest_perf;
+	nominal_perf = perf_caps.nominal_perf;
+
+	if (!highest_perf || !nominal_perf) {
+		pr_debug("Could not retrieve highest or nominal performance\n");
+		return false;
+	}
+
+	perf_ratio = div_u64(highest_perf * SCHED_CAPACITY_SCALE, nominal_perf);
+	if (!perf_ratio) {
+		pr_debug("Non-zero highest/nominal perf values led to a 0 ratio\n");
+		return false;
+	}
+
+	arch_turbo_freq_ratio = perf_ratio;
+	arch_set_max_freq_ratio(false);
+
+	return true;
+}
+#else
+static bool amd_set_max_freq_ratio(void)
+{
+	return false;
+}
+#endif
+
 static void init_counter_refs(void)
 {
 	u64 aperf, mperf;
@@ -2038,7 +2082,7 @@ static void init_counter_refs(void)
 	this_cpu_write(arch_prev_mperf, mperf);
 }
 
-static void init_freq_invariance(bool secondary)
+static void init_freq_invariance(bool secondary, bool cppc_ready)
 {
 	bool ret = false;
 
@@ -2054,6 +2098,12 @@ static void init_freq_invariance(bool secondary)
 
 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
 		ret = intel_set_max_freq_ratio();
+	else if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
+		if (!cppc_ready) {
+			return;
+		}
+		ret = amd_set_max_freq_ratio();
+	}
 
 	if (ret) {
 		init_counter_refs();
@@ -2063,6 +2113,22 @@ static void init_freq_invariance(bool secondary)
 	}
 }
 
+#ifdef CONFIG_ACPI_CPPC_LIB
+static DEFINE_MUTEX(freq_invariance_lock);
+
+void init_freq_invariance_cppc(void)
+{
+	static bool secondary;
+
+	mutex_lock(&freq_invariance_lock);
+
+	init_freq_invariance(secondary, true);
+	secondary = true;
+
+	mutex_unlock(&freq_invariance_lock);
+}
+#endif
+
 static void disable_freq_invariance_workfn(struct work_struct *work)
 {
 	static_branch_disable(&arch_scale_freq_key);
@@ -2112,7 +2178,7 @@ error:
 	schedule_work(&disable_freq_invariance_work);
 }
 #else
-static inline void init_freq_invariance(bool secondary)
+static inline void init_freq_invariance(bool secondary, bool cppc_ready)
 {
 }
 #endif /* CONFIG_X86_64 */
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 7a99b19..a852dc4 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -39,6 +39,7 @@
 #include <linux/ktime.h>
 #include <linux/rwsem.h>
 #include <linux/wait.h>
+#include <linux/topology.h>
 
 #include <acpi/cppc_acpi.h>
 
@@ -688,6 +689,10 @@ static bool is_cppc_supported(int revision, int num_ent)
  *	}
  */
 
+#ifndef init_freq_invariance_cppc
+static inline void init_freq_invariance_cppc(void) { }
+#endif
+
 /**
  * acpi_cppc_processor_probe - Search for per CPU _CPC objects.
  * @pr: Ptr to acpi_processor containing this CPU's logical ID.
@@ -850,6 +855,8 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
 		goto out_free;
 	}
 
+	init_freq_invariance_cppc();
+
 	kfree(output.pointer);
 	return 0;
 

^ permalink raw reply	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2020-12-11  9:36 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-11-12 18:26 [PATCH v4 0/3] Add support for frequency invariance to AMD EPYC Zen2 Giovanni Gherdovich
2020-11-12 18:26 ` [PATCH v4 1/3] x86, sched: Calculate frequency invariance for AMD systems Giovanni Gherdovich
2020-12-03  9:13   ` [tip: sched/core] " tip-bot2 for Nathan Fontenot
2020-12-11  9:34   ` tip-bot2 for Nathan Fontenot
2020-11-12 18:26 ` [PATCH v4 2/3] x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC Giovanni Gherdovich
2020-12-03  9:13   ` [tip: sched/core] " tip-bot2 for Giovanni Gherdovich
2020-12-04 17:03   ` [PATCH v4 RESEND] " Giovanni Gherdovich
2020-12-04 17:10     ` Giovanni Gherdovich
2020-12-11  9:34   ` [tip: sched/core] " tip-bot2 for Giovanni Gherdovich
2020-11-12 18:26 ` [PATCH v4 3/3] x86: Print ratio freq_max/freq_base used in frequency invariance calculations Giovanni Gherdovich
2020-12-03  9:13   ` [tip: sched/core] " tip-bot2 for Giovanni Gherdovich
2020-12-11  9:34   ` tip-bot2 for Giovanni Gherdovich

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