[PATCH v16 0/4] add support for self monitoring

[Tomasz Duszynski <tduszynski@marvell.com>]

This series adds self monitoring support i.e allows to configure and
read performance measurement unit (PMU) counters in runtime without
using perf utility. This has certain advantages when application runs on
isolated cores running dedicated tasks.

Events can be read directly using rte_pmu_read() or using dedicated
tracepoint rte_eal_trace_pmu_read(). The latter will cause events to be
stored inside CTF file.

By design, all enabled events are grouped together and the same group
is attached to lcores that use self monitoring funtionality.

Events are enabled by names, which need to be read from standard
location under sysfs i.e

/sys/bus/event_source/devices/PMU/events

where PMU is a core pmu i.e one measuring cpu events. As of today
raw events are not supported.

v16:
- fix build issue related to ALLOW_EXPERIMENTAL_API not always defined
- rename tracepoints upfront to make it easier to decouple for tracing
- minor doc improvements
- make sure non EAL threads can't read PMU
v15:
- add some basic logs related to API failures
- get rid of thread-local-storage
- do not support MT-safety (which was buggy anyway) in management APIs (rte_pmu_init(),
  rte_pmu_fini(), rte_pmu_add_{event,events_by_pattern}() as it impacts rte_pmu_read()
  performance because more logic needs to be incorporated to handle all corner cases
- improve documentation slightly
- various other improvements here and there
v14:
- replace __atomic_xxx with rte_atomic_xxx
- rebase to dpdk/main since that's a new feature
v13:
- allow init/fini calling from multiple contexts
- get rid of conditional compilation and return erors in case APIs are
  used on unsupported OS
v12:
- rebase old series
- slightly refresh existing documentation
- make sure compiler won't optimize accesses to certain variables during
  event readout
- drop previous Acked-by to respin a fresh review cycle
v11:
- skip fast test in case init fails
v10:
- check permissions before using counters
- do not use internal symbols in exported functions
- address review comments
v9:
- fix 'maybe-uninitialized' warning reported by CI
v8:
- just rebase series
v7:
- use per-lcore event group instead of global table index by lcore-id
- don't add pmu_autotest to fast tests because due to lack of suported
  on every arch
v6:
- move codebase to the separate library
- address review comments
v5:
- address review comments
- fix sign extension while reading pmu on x86
- fix regex mentioned in doc
- various minor changes/improvements here and there
v4:
- fix freeing mem detected by debug_autotest
v3:
- fix shared build
v2:
- fix problems reported by test build infra

Tomasz Duszynski (4):
  lib: add generic support for reading PMU events
  pmu: support reading ARM PMU events in runtime
  pmu: support reading Intel x86_64 PMU events in runtime
  eal: add PMU support to tracing library

 MAINTAINERS                              |   5 +
 app/test/meson.build                     |   1 +
 app/test/test_pmu.c                      |  55 +++
 app/test/test_trace_perf.c               |  10 +
 doc/api/doxy-api-index.md                |   3 +-
 doc/api/doxy-api.conf.in                 |   1 +
 doc/guides/prog_guide/profile_app.rst    |  31 ++
 doc/guides/prog_guide/trace_lib.rst      |  32 ++
 doc/guides/rel_notes/release_24_11.rst   |   7 +
 lib/eal/common/eal_common_trace.c        |   5 +-
 lib/eal/common/eal_common_trace_pmu.c    |  38 ++
 lib/eal/common/eal_common_trace_points.c |   5 +
 lib/eal/common/eal_trace.h               |   4 +
 lib/eal/common/meson.build               |   1 +
 lib/eal/include/rte_eal_trace.h          |  11 +
 lib/eal/meson.build                      |   3 +
 lib/eal/version.map                      |   1 +
 lib/meson.build                          |   1 +
 lib/pmu/meson.build                      |  22 +
 lib/pmu/pmu_arm64.c                      |  94 ++++
 lib/pmu/pmu_private.h                    |  32 ++
 lib/pmu/rte_pmu.c                        | 536 +++++++++++++++++++++++
 lib/pmu/rte_pmu.h                        | 250 +++++++++++
 lib/pmu/rte_pmu_pmc_arm64.h              |  30 ++
 lib/pmu/rte_pmu_pmc_x86_64.h             |  24 +
 lib/pmu/version.map                      |  15 +
 26 files changed, 1215 insertions(+), 2 deletions(-)
 create mode 100644 app/test/test_pmu.c
 create mode 100644 lib/eal/common/eal_common_trace_pmu.c
 create mode 100644 lib/pmu/meson.build
 create mode 100644 lib/pmu/pmu_arm64.c
 create mode 100644 lib/pmu/pmu_private.h
 create mode 100644 lib/pmu/rte_pmu.c
 create mode 100644 lib/pmu/rte_pmu.h
 create mode 100644 lib/pmu/rte_pmu_pmc_arm64.h
 create mode 100644 lib/pmu/rte_pmu_pmc_x86_64.h
 create mode 100644 lib/pmu/version.map

--
2.34.1