Hi,
In Arm processors, there is a hardware PMU (Performance Monitoring
Unit) facility called Statistical Profiling Extension (SPE) that can
gather memory access metrics.
In this patchset, SPE is exploited as an access information sampling
approach to drive NUMA balancing. This sampling approach is
introducedto replace the method based on address space scanning and
hint faults with the access information provided by the hardware.
With this, it is no longer necessary for NUMA balancing to scan over
the address space periodically and rely on task-to-page association
built by NUMA hint faults. Instead, the access samples obtained from
hardware PMU are fed to NUMA balancing as equivalents to page fault.
Except for the replaced sampling approach, the rest of the NUMA
balancing policy is retained to do pages and tasks migrations
according to the samples.
Profiling based on SPE is an valid alternative sampling approach in
NUMA balancing for the optimal page and task placement. This can be
also extended to other architectures as long as there is a hardware
PMU that supports memory access profiling.
An abstract layer mem_sampling is introduced to reserve support for
other kernel features and different types of hardware PMU.
To help evaluate performance of this approach in system, syctl
interfaces are added to enable/disable hardware mem sampling. NUMA
balancing sampling approach can be also switched back to hint-faults-
based approach dynamically.
TODOs
Currently, SPE for NUMA balance does not support PMD-level page
migration, but it will be supported in later version.
Changes since v4:
-- some patch check warning fixs, no functional change.
Changes since v3:
-- some clean code, no functional change.
Changes since v2:
-- clean code and commit fixs, no functional change.
Changes since v1:
-- clean code, no functional change.
Ze Zuo (11):
drivers/arm/spe: In-kernel SPE driver for page access profiling
mm: Add PMU based memory sampling abstract layer
mm/mem_sampling.c: Add controlling interface for mem_sampling
sched: Enable per-process mem_sampling from sched switch path
mm/mem_sampling.c: Drive NUMA balancing via mem_sampling access data
mm/mem_sampling.c: Add controlling interface for mem_sampling on numa
balance
tracing, numa balance: add trace events for numa data caused by
mem_sampling
driver/arm/spe: make mem_sampling and perf reuse arm spe driver
tracing, mem-sampling-sample: Adding tracking events to
hardware-sampled page access
samples/bpf: Add program for memory access by spe
config: Enable memory sampling based pmu for numa balance by default
arch/arm64/configs/openeuler_defconfig | 3 +
drivers/Kconfig | 2 +
drivers/Makefile | 1 +
drivers/arm/Kconfig | 2 +
drivers/arm/spe/Kconfig | 11 +
drivers/arm/spe/Makefile | 2 +
drivers/arm/spe/spe-decoder/Makefile | 2 +
drivers/arm/spe/spe-decoder/arm-spe-decoder.c | 213 +++++
drivers/arm/spe/spe-decoder/arm-spe-decoder.h | 74 ++
.../arm/spe/spe-decoder/arm-spe-pkt-decoder.c | 227 +++++
.../arm/spe/spe-decoder/arm-spe-pkt-decoder.h | 153 ++++
drivers/arm/spe/spe.c | 854 ++++++++++++++++++
drivers/arm/spe/spe.h | 130 +++
drivers/perf/Kconfig | 2 +-
drivers/perf/arm_pmu_acpi.c | 30 +-
drivers/perf/arm_spe_pmu.c | 371 ++------
include/linux/mem_sampling.h | 109 +++
include/linux/perf/arm_pmu.h | 8 +
include/trace/events/kmem.h | 80 ++
kernel/sched/core.c | 2 +
kernel/sched/fair.c | 12 +
mm/Kconfig | 24 +
mm/Makefile | 1 +
mm/mem_sampling.c | 514 +++++++++++
samples/bpf/spe/Makefile | 26 +
samples/bpf/spe/Makefile.arch | 47 +
samples/bpf/spe/README.md | 0
samples/bpf/spe/spe-record.bpf.c | 40 +
samples/bpf/spe/spe-record.h | 47 +
samples/bpf/spe/spe-record.user.c | 116 +++
30 files changed, 2791 insertions(+), 312 deletions(-)
create mode 100644 drivers/arm/Kconfig
create mode 100644 drivers/arm/spe/Kconfig
create mode 100644 drivers/arm/spe/Makefile
create mode 100644 drivers/arm/spe/spe-decoder/Makefile
create mode 100644 drivers/arm/spe/spe-decoder/arm-spe-decoder.c
create mode 100644 drivers/arm/spe/spe-decoder/arm-spe-decoder.h
create mode 100644 drivers/arm/spe/spe-decoder/arm-spe-pkt-decoder.c
create mode 100644 drivers/arm/spe/spe-decoder/arm-spe-pkt-decoder.h
create mode 100644 drivers/arm/spe/spe.c
create mode 100644 drivers/arm/spe/spe.h
create mode 100644 include/linux/mem_sampling.h
create mode 100644 mm/mem_sampling.c
create mode 100644 samples/bpf/spe/Makefile
create mode 100644 samples/bpf/spe/Makefile.arch
create mode 100644 samples/bpf/spe/README.md
create mode 100644 samples/bpf/spe/spe-record.bpf.c
create mode 100644 samples/bpf/spe/spe-record.h
create mode 100644 samples/bpf/spe/spe-record.user.c
--
2.33.0