Re: [PATCH v3 2/3] perf sched latency: Auto-scale latency and runtime display units

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Column misalignment in the 'perf sched latency' output due to data rows being narrower than their corresponding headers.
--

--- Patch [2]: [PATCH v3 2/3] perf sched latency: Auto-scale latency and runtime display units ---
commit 2e23c112768cacfb80cab8592bd0a0612fb05704
Author: Aaron Tomlin <atomlin@atomlin.com>

perf sched latency: Auto-scale latency and runtime display units

This commit introduces dynamic scaling for latency and runtime values in
'perf sched latency', outputting them in ns, us, ms, or s. It also renames
the column headers to reflect the variable units.

> diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
> index b3cf678573e0a..8c83dc423b571 100644
> --- a/tools/perf/builtin-sched.c
> +++ b/tools/perf/builtin-sched.c
[ ... ]
> @@ -1430,14 +1443,17 @@ static void output_lat_thread(struct perf_sched *sched, struct work_atoms *work_
[ ... ]
> -	printf("|%11.3f ms |%9" PRIu64 " | avg:%8.3f ms | max:%8.3f ms | max start: %12s s | max end: %12s s\n",
> -	      (double)work_list->total_runtime / NSEC_PER_MSEC,
> -		 work_list->nb_atoms, (double)avg / NSEC_PER_MSEC,
> -		 (double)work_list->max_lat / NSEC_PER_MSEC,
> -		 max_lat_start, max_lat_end);
> +	printf("|%14s |%9" PRIu64 " | avg:%11s | max:%11s | max start: %12s s | max end: %12s s\n",
> +	       runtime_lat,
> +	       work_list->nb_atoms, avg_lat, max_lat,
> +	       max_lat_start, max_lat_end);

[Severity: Low]
Does this format change cause the data columns to misalign with the table
headers during output?

The updated data row format specifiers " avg:%11s " and " max:%11s " expand
to exactly 16 characters each (1 space, 4 chars for the prefix, and 11 chars
for the string). 

In the old format, " avg:%8.3f ms " expanded to 17 characters, which
perfectly matched the 17-character width of the corresponding table headers
shown below.

[ ... ]
> @@ -3612,7 +3629,7 @@ static int perf_sched__lat(struct perf_sched *sched)
[ ... ]
>  	printf("\n -------------------------------------------------------------------------------------------------------------------------------------------\n");
> -	printf("  Task                  |   Runtime ms  |  Count   | Avg delay ms    | Max delay ms    | Max delay start           | Max delay end          |\n");
> +	printf("  Task                  |   Runtime     |  Count   | Avg delay       | Max delay       | Max delay start           | Max delay end          |\n");

Because the "Avg delay" and "Max delay" header columns are 17 characters
wide (" Avg delay       " and " Max delay       "), shrinking the data row
columns by 1 character each will shift the subsequent data columns leftward,
breaking vertical alignment.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260726032533.712462-1-atomlin@atomlin.com?part=2