Re: [PATCH v2 02/12] perf test: Truncate test description to fit terminal width

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Incorrect File Descriptor Check for Terminal Width
--

commit f74a2825a5f95152494bcb0ab5c482df7aacb93e
Author: Ian Rogers <irogers@google.com>

perf test: Truncate test description to fit terminal width

This commit dynamically queries the terminal width to truncate printed test
descriptions. This prevents output corruption caused by long descriptions
wrapping around and breaking the carriage return delete sequences used in
the parallel test harness.

> diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
> --- a/tools/perf/tests/builtin-test.c
> +++ b/tools/perf/tests/builtin-test.c
[ ... ]
> @@ -413,19 +417,64 @@ static char *xml_escape(const char *str)
>  	return res ? res : strdup("");
>  }
>  
> +static int get_term_width(void)
> +{
> +	struct winsize ws;
> +	int cols = 80;
> +	int term_width;
> +
> +	if (!isatty(1))

[Severity: Medium]
Is isatty(1) the correct file descriptor to check here?

The test progress and results are printed to stderr via pr_info() and explicit
color_fprintf(stderr, ...) calls.

If a user runs perf test > /dev/null, stdout is redirected but stderr remains a
TTY. This check would return false and bypass truncation, causing the long
descriptions to wrap and corrupt the terminal display.

Conversely, if a user redirects stderr to a log file but leaves stdout as a
terminal (perf test 2> log.txt), this check evaluates to true and unnecessarily
truncates the log file output, destroying diagnostic information.

Should this check isatty(2) instead, since the output is sent to stderr?

> +		return 10000;
> +
> +	get_term_dimensions(&ws);

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260616061404.41929-1-irogers@google.com?part=2