Re: [PATCH 2/3] perf test: Introduce '-w --list' to list the available workloads

[James Clark <james.clark@linaro.org>]

On 11/10/2024 3:39 pm, Arnaldo Carvalho de Melo wrote:
> From: Arnaldo Carvalho de Melo <acme@redhat.com>
> 
> Using it:
> 
>    $ perf test -w noplop
>    No workload found: noplop
>    $
>    $ perf test -w
>     Error: switch `w' requires a value
>     Usage: perf test [<options>] [{list <test-name-fragment>|[<test-name-fragments>|<test-numbers>]}]
> 
>        -w, --workload <work>
>                              workload to run for testing, use '-w --list' to list the available ones.
>    $
>    $ perf test -w --list
>    noploop
>    thloop
>    leafloop
>    sqrtloop
>    brstack
>    datasym
>    landlock
>    $
> 
> Would be good at some point to have a description in 'struct test_workload'.
> 
> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: Ian Rogers <irogers@google.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: Kan Liang <kan.liang@linux.intel.com>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> ---
>   tools/perf/tests/builtin-test.c | 18 +++++++++++++++++-
>   1 file changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
> index 2201f7ed432ce9f2..f0d10d2dd0d40019 100644
> --- a/tools/perf/tests/builtin-test.c
> +++ b/tools/perf/tests/builtin-test.c
> @@ -505,10 +505,26 @@ static int perf_test__list(int argc, const char **argv)
>   	return 0;
>   }
>   
> +static int workloads__fprintf_list(FILE *fp)
> +{
> +	struct test_workload *twl;
> +	int printed = 0;
> +
> +	workloads__for_each(twl)
> +		printed += fprintf(fp, "%s\n", twl->name);
> +
> +	return printed;
> +}
> +
>   static int run_workload(const char *work, int argc, const char **argv)
>   {
>   	struct test_workload *twl;
>   
> +	if (!strcmp(work, "--list")) {
> +		workloads__fprintf_list(stdout);
> +		return 0;
> +	}
> +

Very minor nit, but I think searching the workload name for an argument 
instead of having a 'proper' toplevel argument seems a bit weird, but I 
can see why you did it that way.

But maybe something like this might be a bit more readable especially 
when searching in the usual places for an argument. And in the future 
might survive auto doc attempts of known arguments:

   $ perf test --list-workloads

And add it with OPT_BOOLEAN() etc.

>   	workloads__for_each(twl) {
>   		if (!strcmp(twl->name, work))
>   			return twl->func(argc, argv);
> @@ -544,7 +560,7 @@ int cmd_test(int argc, const char **argv)
>   	OPT_BOOLEAN('p', "parallel", &parallel, "Run the tests in parallel"),
>   	OPT_BOOLEAN('S', "sequential", &sequential,
>   		    "Run the tests one after another rather than in parallel"),
> -	OPT_STRING('w', "workload", &workload, "work", "workload to run for testing"),
> +	OPT_STRING('w', "workload", &workload, "work", "workload to run for testing, use '-w --list' to list the available ones."),
>   	OPT_STRING(0, "dso", &dso_to_test, "dso", "dso to test"),
>   	OPT_STRING(0, "objdump", &test_objdump_path, "path",
>   		   "objdump binary to use for disassembly and annotations"),