Re: [RFC PATCH bpf-next 6/6] selftests/bpf: Add XDP load-balancer benchmark run script

[sashiko-bot@kernel.org]

Sashiko AI review found 1 potential issue(s):
- [Medium] The script's error handling is bypassed by `set -e` if the benchmark tool fails.
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commit 676755d117c703df4634ef7adbb680cae370c16a
Author: Puranjay Mohan <puranjay@kernel.org>

selftests/bpf: Add XDP load-balancer benchmark run script

This commit adds a convenience script to run all 24 XDP load-balancer
benchmark scenarios. It executes the benchmarks and formats the results
into a table displaying median, standard deviation, and percentiles.

> diff --git a/tools/testing/selftests/bpf/benchs/run_bench_xdp_lb.sh b/tools/testing/selftests/bpf/benchs/run_bench_xdp_lb.sh
> new file mode 100755
> index 0000000000000..1bde3898dfb63
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/benchs/run_bench_xdp_lb.sh
> @@ -0,0 +1,84 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +
> +source ./benchs/run_common.sh
> +
> +set -eufo pipefail

[ ... ]

> +function run_scenario()
> +{
> +	local sc="$1"
> +	shift
> +	local output rline
> +
> +	output=$($RUN --scenario "$sc" "$@" 2>&1)

Will this assignment cause the entire script to abort immediately if the
benchmark tool fails?

Because set -e is enabled at the top of the script and output was declared
separately as a local variable on the previous line, this assignment
evaluates to the exact exit status of the command substitution. If the
benchmark tool returns a non-zero exit code (for example, due to an
unsupported XDP feature), the script will terminate right here.

This appears to bypass the intended error handling fallback below that prints
"ERR". Would appending || true to the assignment ensure the error handling
block can execute as intended?

> +	rline=$(echo "$output" | grep '^RESULT ' || true)
> +
> +	if [ -z "$rline" ]; then
> +		printf "$ROW" "$sc" "ERR" "-" "-" "-" "-" "-" "-" "-"
> +		return
> +	fi

[ ... ]

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Sashiko AI review · https://sashiko.dev/#/patchset/20260420111726.2118636-1-puranjay@kernel.org?part=6