[PATCH v3 00/14] perf stat: Decouple printing API and introduce streaming zero-allocation printers

[Ian Rogers]

This is V3 of the patch series implementing the decoupled perf stat printing
architecture. This series fully separates the format-specific display engines
(STD, CSV, JSON) into distinct isolated files, and guarantees 100% streaming,
zero-allocation output for interval metric-only JSON data to avoid debug
artifact overwrites and large allocations on extended system-wide runs.

Changes since v2:
 - Fixed trailing newline count and padding logic for wide metric names
   in standard console (STD) metric-only interval modes, resolving reports
   from Sashiko AI.
 - Resolved aggr header label misalignments for Socket/Die/Node/Cache modes.
 - Addressed debug artifact overwrite bugs in the `stat_metrics_values.sh`
   rules validation engine by correctly scoping execution passes and preserving
   artifacts upon failure.
 - Reverted all reflow diff noise in `builtin-stat.c` and legacy metric print
   functions in `util/stat-display.c` per feedback from Arnaldo.
 - Converted all format callback file creations to use standard `//` SPDX header
   formatting directly in the patch series to prevent downstream diff noise.
 - Resolved all internal brace styles, variable declaration spacing, and unwrapped
   commit description warnings reported by checkpatch.pl.
 - Added all requested Acked-by tags from reviewers.

Ian Rogers (14):
  perf stat: Introduce core generic print traversal engine and header
    stubs
  perf stat: Implement standard console (STD) formatting callbacks
  perf stat: Extend STD output linter to test basic New API checks
  perf stat: Extend STD output linter to test core aggregation checks
  perf stat: Extend STD output linter to test advanced PMU checks
  perf stat: Extend STD output linter to test metric-only checks
  perf stat: Implement CSV formatting callbacks
  perf stat: Extend CSV output linter to test core aggregation checks
  perf stat: Extend CSV output linter to test advanced PMU and
    metric-only checks
  perf stat: Implement streaming JSON formatting callbacks
  perf stat: Extend JSON output linter to test core aggregation checks
  perf stat: Extend JSON output linter to test advanced PMU and
    metric-only checks
  perf stat: Add --new support to PMU metrics Python validator
  perf stat: Extend PMU metrics value linter to validate --new outputs

 tools/perf/builtin-stat.c                     |  96 +-
 .../tests/shell/lib/perf_metric_validation.py |  12 +-
 tools/perf/tests/shell/stat+csv_output.sh     |  19 +
 tools/perf/tests/shell/stat+json_output.sh    |  74 +-
 tools/perf/tests/shell/stat+std_output.sh     |  18 +
 tools/perf/tests/shell/stat_metrics_values.sh |  22 +-
 tools/perf/util/Build                         |   4 +
 tools/perf/util/stat-display.c                |   6 +-
 tools/perf/util/stat-print-csv.c              | 534 +++++++++++
 tools/perf/util/stat-print-json.c             | 330 +++++++
 tools/perf/util/stat-print-std.c              | 828 ++++++++++++++++++
 tools/perf/util/stat-print.c                  | 489 +++++++++++
 tools/perf/util/stat-print.h                  | 133 +++
 tools/perf/util/stat.h                        |   2 +
 14 files changed, 2488 insertions(+), 79 deletions(-)
 create mode 100644 tools/perf/util/stat-print-csv.c
 create mode 100644 tools/perf/util/stat-print-json.c
 create mode 100644 tools/perf/util/stat-print-std.c
 create mode 100644 tools/perf/util/stat-print.c
 create mode 100644 tools/perf/util/stat-print.h

-- 
2.55.0.141.g00534a21ce-goog