Re: [PATCH v1 1/2] perf stat: Fix duplicate output with --for-each-cgroup

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Incomplete state cloning in `evsel__clone()` breaks TPEBS latency fallback metrics and BPF counters for duplicated events.
--

--- Patch [1]: [PATCH v1 1/2] perf stat: Fix duplicate output with --for-each-cgroup ---
commit 10359224b851cd21a00edee0e074af745faf63be
Author: Namhyung Kim <namhyung@kernel.org>

perf stat: Fix duplicate output with --for-each-cgroup

This commit fixes duplicate event output in perf stat when using the
--for-each-cgroup option. It addresses the issue by copying several
fields that were previously missed during evsel__clone().

> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index ea9fa04429f08..ee0b5b4c536c8 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -610,12 +610,18 @@ struct evsel *evsel__clone(struct evsel *dest, struct evsel *orig)
>  	evsel->percore = orig->percore;
>  	evsel->precise_max = orig->precise_max;
>  	evsel->is_libpfm_event = orig->is_libpfm_event;
> +	evsel->skippable = orig->skippable;
> +	evsel->retire_lat = orig->retire_lat;

[Severity: Medium]
When copying the retire_lat flag, do we also need to copy the associated
retirement_latency struct and the bpf_counter flag to avoid a regression?

Without copying the retirement_latency struct (mean, min, max), a cloned
event falling back to TPEBS might use a zeroed struct and incorrectly
calculate 0.0 latency instead of using the parsed values. 

Similarly, omitting the bpf_counter flag might cause cloned BPF events
to silently bypass BPF counting.

> +	evsel->dont_regroup = orig->dont_regroup;
>  
>  	evsel->exclude_GH = orig->exclude_GH;
>  	evsel->sample_read = orig->sample_read;

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Sashiko AI review · https://sashiko.dev/#/patchset/20260708233103.1359713-1-namhyung@kernel.org?part=1