[PATCH v7 00/10] Add RAPL core energy counter support for AMD CPUs

From: Dhananjay Ugwekar
Date: Fri Nov 15 2024 - 01:08:59 EST


Currently the energy-cores event in the power PMU aggregates energy
consumption data at a package level. On the other hand the core energy
RAPL counter in AMD CPUs has a core scope (which means the energy
consumption is recorded separately for each core). Earlier efforts to add
the core event in the power PMU had failed [1], due to the difference in
the scope of these two events. Hence, there is a need for a new core scope
PMU.

This patchset adds a new "power_core" PMU alongside the existing
"power" PMU, which will be responsible for collecting the new
"energy-core" event.

Tested the package level and core level PMU counters with workloads
pinned to different CPUs.

Results with workload pinned to CPU 4 in core 4 on an AMD Zen4 Genoa
machine:

$ sudo perf stat --per-core -e power_core/energy-core/ -- taskset -c 4 stress-ng --matrix 1 --timeout 5s
stress-ng: info: [21250] setting to a 5 second run per stressor
stress-ng: info: [21250] dispatching hogs: 1 matrix
stress-ng: info: [21250] successful run completed in 5.00s

Performance counter stats for 'system wide':

S0-D0-C0 1 0.00 Joules power_core/energy-core/
S0-D0-C1 1 0.00 Joules power_core/energy-core/
S0-D0-C2 1 0.00 Joules power_core/energy-core/
S0-D0-C3 1 0.00 Joules power_core/energy-core/
S0-D0-C4 1 8.43 Joules power_core/energy-core/
S0-D0-C5 1 0.00 Joules power_core/energy-core/
S0-D0-C6 1 0.00 Joules power_core/energy-core/
S0-D0-C7 1 0.00 Joules power_core/energy-core/
S0-D1-C8 1 0.00 Joules power_core/energy-core/
S0-D1-C9 1 0.00 Joules power_core/energy-core/
S0-D1-C10 1 0.00 Joules power_core/energy-core/

v6 Link: https://lore.kernel.org/linux-perf-users/20241025111348.3810-1-Dhananjay.Ugwekar@xxxxxxx/

v6 Changes:
* Pickup rb, tb tags by Rui and Gautham
* Modify the rapl_pmu_idx variable to unsigned int, and modify
the comment in get_rapl_pmu_idx() in patch 3 (Gautham)
* Modified commit msg in patch 1 (Gautham)

Base: tip/perf/core

[1]: https://lore.kernel.org/lkml/3e766f0e-37d4-0f82-3868-31b14228868d@xxxxxxxxxxxxxxx/

Dhananjay Ugwekar (9):
perf/x86/rapl: Remove the unused get_rapl_pmu_cpumask() function
perf/x86/rapl: Remove the cpu_to_rapl_pmu() function
perf/x86/rapl: Rename rapl_pmu variables
perf/x86/rapl: Make rapl_model struct global
perf/x86/rapl: Add arguments to the init and cleanup functions
perf/x86/rapl: Modify the generic variable names to *_pkg*
perf/x86/rapl: Remove the global variable rapl_msrs
perf/x86/rapl: Move the cntr_mask to rapl_pmus struct
perf/x86/rapl: Add core energy counter support for AMD CPUs

K Prateek Nayak (1):
x86/topology: Introduce topology_logical_core_id()

Documentation/arch/x86/topology.rst | 4 +
arch/x86/events/rapl.c | 414 ++++++++++++++++----------
arch/x86/include/asm/processor.h | 1 +
arch/x86/include/asm/topology.h | 1 +
arch/x86/kernel/cpu/debugfs.c | 1 +
arch/x86/kernel/cpu/topology_common.c | 1 +
6 files changed, 272 insertions(+), 150 deletions(-)

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2.34.1