Re: [PATCH 2/2] perf/annotate: Fix missing branch counter column in TUI mode

[sashiko-bot@kernel.org]

Sashiko AI review found 1 potential issue(s):
- [Medium] The branch counter column is now enabled in standard stdio mode where it cannot be populated, resulting in a useless empty column in the output.
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commit afd424a34255fcd5587246caa606560bc9b916c8
Author: Thomas Falcon <thomas.falcon@intel.com>

perf/annotate: Fix missing branch counter column in TUI mode

This commit moves the check for enabling the branch counter column into
__cmd_annotate() so it occurs after events have been processed and the
counter is updated.

> diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
> index 5e57b78548f42..7fe23b05306f8 100644
> --- a/tools/perf/builtin-annotate.c
> +++ b/tools/perf/builtin-annotate.c
> @@ -563,6 +563,9 @@ static int __cmd_annotate(struct perf_annotate *ann)
>  	if (ret)
>  		goto out;
>  
> +	if (session->evlist->nr_br_cntr > 0)
> +		annotate_opts.show_br_cntr = true;
> +

Will this cause an empty branch counter column to be displayed in standard
stdio mode?

The original code restricted this check to TUI and stdio2 modes where
use_browser == 1 or annotate.use_stdio2 is true. By moving the assignment
here, it becomes unconditional.

In standard stdio mode, process_branch_callback() is skipped when adding
samples, so branch stack data is not aggregated into the annotation notes.
This leaves the counter data at 0 for all instructions. Could this result
in the output rendering the column title but printing only empty spaces for
all the rows?

[ ... ]

> @@ -928,8 +931,6 @@ int cmd_annotate(int argc, const char **argv)
>  	 */
>  	if ((use_browser == 1 || annotate.use_stdio2) && annotate.has_br_stack) {
>  		sort__mode = SORT_MODE__BRANCH;
> -		if (annotate.session->evlist->nr_br_cntr > 0)
> -			annotate_opts.show_br_cntr = true;
>  	}
>  
>  	if (setup_sorting(/*evlist=*/NULL, perf_session__env(annotate.session)) < 0)

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Sashiko AI review · https://sashiko.dev/#/patchset/20260410194000.219846-1-thomas.falcon@intel.com?part=2