Re: [PATCH v4 3/3] perf test: Avoid stack trace noise in verbose=1 failure snippets

[sashiko-bot@kernel.org]

> When a test fails with a signal or times out, child_test_sig_handler()
> appends '---- unexpected signal (<sig>) ----' followed by a multi-line
> stack trace ('    #0 ...' through '_start').
> 
> In verbose=1 mode, print_test_failure_snippet() selects up to
> failure_snippet_lines (10) lines:
> - Pass 1 selects lines matching failure keywords plus their immediate
>   next line ('    #0 ... in child_test_sig_handler').
> - Pass 2 fills the remaining quota by scanning backwards from the end
>   of the output buffer, which consumes the remaining lines on outermost
>   stack frames ('handle_internal_command', 'run_argv', 'main',
>   '__libc_start_main', '_start') and hides the trailing test output
>   showing where the test had run to.
> 
> Improve print_test_failure_snippet() by:
> - Skipping blank lines and stack trace lines ('    #<digit>...') when
>   selecting context in Pass 1 and when scanning backwards from the end
>   in Pass 2, with a Pass 3 fallback from the top of the buffer if quota
>   still remains.
> - Prioritizing the non-blank line immediately preceding
>   '---- unexpected signal' so there is no '...' gap before the signal
>   message.
> - Only printing '...' between selected lines when at least one non-blank
>   line was omitted between them.
> 
> Assisted-by: Antigravity:gemini-3.1-pro
> Signed-off-by: Ian Rogers <irogers@google.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20261012234724.721224-1-irogers@google.com?part=3