Re: [PATCH v6] perf stat: Include PMU name and split uncore events per PMU in metric-only JSON output

[sashiko-bot@kernel.org]

> When running `perf stat` with `-A` (--no-aggr) and `--metric-only` in
> JSON output mode (`-j`), `perf stat` evaluates metric expressions
> across all matching PMUs (including uncore PMUs like `uncore_iio_0`,
> `uncore_iio_1`, etc.).
> 
> However, `perf stat` previously formatted JSON output by printing only
> "cpu" : "<id>" and grouping all metric values on a single line per CPU
> without identifying which PMU instance evaluated each metric. As a
> result, when an uncore event spans multiple PMU boxes, `perf stat`
> printed repeated, ambiguous metric keys without PMU names.
> 
> Fix this by:
> 1. Including "pmu" : "<pmu_name>" in print_aggr_id_json when evsel->pmu
>    is a non-core or hybrid PMU in AGGR_NONE mode (-A). Tool events are
>    not labeled as they don't belong to a hardware PMU instance.
> [ ... ]
>   {"interval" : 1.000314908, "cpu" : "56", "pmu" : "uncore_iio_1", "MB/s  iio_bandwidth_read" : "0.0"}
>   {"interval" : 1.000314908, "cpu" : "56", "pmu" : "uncore_iio_11", "MB/s  iio_bandwidth_read" : "0.0"}
> 
> Assisted-by: Gemini:gemini-3.1-pro-preview
> Signed-off-by: Chun-Tse Shao <ctshao@google.com>

Sashiko has reviewed this patch and found no issues.

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Sashiko AI review · https://sashiko.dev/#/patchset/20261027203115.2647914-1-ctshao@google.com?part=1