[RFC PATCH v1 0/5] TPEBS counting mode support

[weilin . wang]

From: Weilin Wang <weilin.wang@xxxxxxxxx>

TPEBS is one of the features provided by the next generation of Intel PMU.
Please refer to Section 8.4.1 of "Intel® Architecture Instruction Set Extensions
Programming Reference" [1] for more details about this feature.

This set of patches supports TPEBS in counting mode. The code works in the
following way: it forks a perf record process from perf stat when retire_latency
of one or more events are used in a metric formula. Perf stat would send a
SIGTERM signal to perf record before it needs the retire latency value for
metric calculation. Perf stat will then process sample data to extract the
retire latency data for metric calculations. Currently, the code uses the
arithmetic average of retire latency values.

[1] https://www.intel.com/content/www/us/en/content-details/812218/intel-architecture-instruction-set-extensions-programming-reference.html?wapkw=future%20features

  perf stat: Parse and find tpebs events when parsing metrics to prepare
    for perf record sampling
  perf stat: Fork and launch perf record when perf stat needs to get
    retire latency value for a metric.
  perf stat: Add retire latency values into the expr_parse_ctx to
    prepare for final metric calculation
  perf stat: Create another thread for sample data processing
  perf stat: Add retire latency print functions to print out at the very
    end of print out

 tools/perf/builtin-stat.c      | 222 ++++++++++++++++++++++++++++++++-
 tools/perf/util/data.c         |   4 +
 tools/perf/util/data.h         |   1 +
 tools/perf/util/metricgroup.c  |  61 +++++++--
 tools/perf/util/metricgroup.h  |  18 ++-
 tools/perf/util/stat-display.c |  65 ++++++++++
 tools/perf/util/stat-shadow.c  |  18 +++
 tools/perf/util/stat.h         |   5 +
 8 files changed, 376 insertions(+), 18 deletions(-)

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2.43.0