Re: [PATCH v5 2/3] perf sched map: Add support for multiple task names using CSV

[Namhyung Kim <namhyung@kernel.org>]

On Wed, Jun 26, 2024 at 02:45:49PM +0530, Madadi Vineeth Reddy wrote:
> To track the scheduling patterns of multiple tasks simultaneously,
> multiple task names can be specified using a comma separator
> without any whitespace.
> 
> Sample output for --task-name perf,wdavdaemon
> =============
>  .  *A0  .   .   .   .   -   .   131040.641346 secs A0 => wdavdaemon:62509
>  .   A0 *B0  .   .   .   -   .   131040.641378 secs B0 => wdavdaemon:62274
>  -  *-   -   -   -   -   -   -   131040.641379 secs
> *C0  .   B0  .   .   .   .   .   131040.641572 secs C0 => wdavdaemon:62283
> 
> ...
> 
>  -  *-   -   -   -   -   -   -   131041.395649 secs
>  .   .   .   .   .   .   .  *X2  131041.403969 secs X2 => perf:70211
>  -   -   -   -   -   -   -  *-   131041.404006 secs
> 
> Suggested-by: Namhyung Kim <namhyung@kernel.org>
> Reviewed-and-tested-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
> Signed-off-by: Madadi Vineeth Reddy <vineethr@linux.ibm.com>
> ---
>  tools/perf/Documentation/perf-sched.txt |  5 +-
>  tools/perf/builtin-sched.c              | 77 +++++++++++++++++++++----
>  2 files changed, 69 insertions(+), 13 deletions(-)
> 
> diff --git a/tools/perf/Documentation/perf-sched.txt b/tools/perf/Documentation/perf-sched.txt
> index 3255e5b8e74b..3095e280eb92 100644
> --- a/tools/perf/Documentation/perf-sched.txt
> +++ b/tools/perf/Documentation/perf-sched.txt
> @@ -131,9 +131,10 @@ OPTIONS for 'perf sched map'
>  	Highlight the given pids.
>  
>  --task-name <task>::
> -	Map output only for the given task name. The sched-out
> +	Map output only for the given task name(s). Separate the
> +	task names with a comma (without whitespace). The sched-out
>  	time is printed and is represented by '*-' for the given
> -	task name
> +	task name(s).
>  	('-' indicates other tasks while '.' is idle).
>  
>  OPTIONS for 'perf sched timehist'
> diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
> index 57f166662d54..ecb43deb9d74 100644
> --- a/tools/perf/builtin-sched.c
> +++ b/tools/perf/builtin-sched.c
> @@ -1540,24 +1540,72 @@ map__findnew_thread(struct perf_sched *sched, struct machine *machine, pid_t pid
>  	return thread;
>  }
>  
> -static bool sched_match_task(const char *comm_str, const char *commands)
> +struct CommandList {

Please don't use camel case.

> +	char **command_list;
> +	int command_count;

If you name the list as commands (or cmds) you can remove the prefix and
use it like commands->list or cmds->count.

Actually I was thinking about strlist API and it'd do most of the work
you did here.  You may want to add the fuzzy (or substring) matching
there.

> +};
> +
> +static void free_command_list(struct CommandList *cmd_list)
> +{
> +	if (cmd_list) {
> +		for (int i = 0; i < cmd_list->command_count; i++)
> +			free(cmd_list->command_list[i]);
> +		free(cmd_list->command_list);
> +		free(cmd_list);
> +	}

Then it could be just strlist__delete().


> +}
> +
> +static struct CommandList *parse_commands(const char *commands)
>  {
>  	char *commands_copy = NULL;
> +	struct CommandList *cmd_list = NULL;
>  	char *token = NULL;
> -	bool match_found = false;
>  
>  	commands_copy = strdup(commands);
>  	if (commands_copy == NULL)
>  		return NULL;
>  
> +	cmd_list = malloc(sizeof(struct CommandList));
> +	if (cmd_list == NULL) {
> +		free(commands_copy);
> +		return NULL;
> +	}
> +
> +	cmd_list->command_count = 0;
> +	cmd_list->command_list = NULL;

You can use zalloc() and remove the zero initialization.


> +
>  	token = strtok(commands_copy, ",");
> +	while (token != NULL) {
> +		cmd_list->command_list = realloc(cmd_list->command_list, sizeof(char *)
> +							*(cmd_list->command_count + 1));
> +		if (cmd_list->command_list == NULL) {
> +			free_command_list(cmd_list);
> +			free(commands_copy);
> +			return NULL;
> +		}
>  
> -	while (token != NULL && !match_found) {
> -		match_found = !strcmp(comm_str, token);
> +		cmd_list->command_list[cmd_list->command_count] = strdup(token);
> +		if (cmd_list->command_list[cmd_list->command_count] == NULL) {
> +			free_command_list(cmd_list);
> +			free(commands_copy);
> +			return NULL;
> +		}
> +
> +		cmd_list->command_count++;
>  		token = strtok(NULL, ",");
>  	}
>  
>  	free(commands_copy);
> +	return cmd_list;

And this could be just `strlist__new(commands, NULL)`.

Thanks,
Namhyung


> +}
> +
> +static bool sched_match_task(const char *comm_str, struct CommandList *cmd_list)
> +{
> +	bool match_found = false;
> +
> +	for (int i = 0; i < cmd_list->command_count && !match_found; i++)
> +		match_found = !strcmp(comm_str, cmd_list->command_list[i]);
> +
>  	return match_found;
>  }
>  
> @@ -1624,6 +1672,8 @@ static int map_switch_event(struct perf_sched *sched, struct evsel *evsel,
>  	char stimestamp[32];
>  	const char *str;
>  
> +	struct CommandList *cmd_list = NULL;
> +
>  	BUG_ON(this_cpu.cpu >= MAX_CPUS || this_cpu.cpu < 0);
>  
>  	if (this_cpu.cpu > sched->max_cpu.cpu)
> @@ -1664,7 +1714,11 @@ static int map_switch_event(struct perf_sched *sched, struct evsel *evsel,
>  	sched->curr_thread[this_cpu.cpu] = thread__get(sched_in);
>  	sched->curr_out_thread[this_cpu.cpu] = thread__get(sched_out);
>  
> +	if (sched->map.task_name)
> +		cmd_list = parse_commands(sched->map.task_name);
> +
>  	new_shortname = 0;
> +	str = thread__comm_str(sched_in);
>  	if (!tr->shortname[0]) {
>  		if (!strcmp(thread__comm_str(sched_in), "swapper")) {
>  			/*
> @@ -1673,8 +1727,7 @@ static int map_switch_event(struct perf_sched *sched, struct evsel *evsel,
>  			 */
>  			tr->shortname[0] = '.';
>  			tr->shortname[1] = ' ';
> -		} else if (!sched->map.task_name || sched_match_task(thread__comm_str(sched_in),
> -								sched->map.task_name)) {
> +		} else if (!sched->map.task_name || sched_match_task(str, cmd_list)) {
>  			tr->shortname[0] = sched->next_shortname1;
>  			tr->shortname[1] = sched->next_shortname2;
>  
> @@ -1703,15 +1756,15 @@ static int map_switch_event(struct perf_sched *sched, struct evsel *evsel,
>  	 * Check which of sched_in and sched_out matches the passed --task-name
>  	 * arguments and call the corresponding print_sched_map.
>  	 */
> -	if (sched->map.task_name && !sched_match_task(str, sched->map.task_name)) {
> -		if (!sched_match_task(thread__comm_str(sched_out), sched->map.task_name))
> +	if (sched->map.task_name && !sched_match_task(str, cmd_list)) {
> +		if (!sched_match_task(thread__comm_str(sched_out), cmd_list))
>  			goto out;
>  		else
>  			goto sched_out;
>  
>  	} else {
>  		str = thread__comm_str(sched_out);
> -		if (!(sched->map.task_name && !sched_match_task(str, sched->map.task_name)))
> +		if (!(sched->map.task_name && !sched_match_task(str, cmd_list)))
>  			proceed = 1;
>  	}
>  
> @@ -1758,8 +1811,10 @@ static int map_switch_event(struct perf_sched *sched, struct evsel *evsel,
>  	color_fprintf(stdout, color, "\n");
>  
>  out:
> -	if (sched->map.task_name)
> +	if (sched->map.task_name) {
> +		free_command_list(cmd_list);
>  		thread__put(sched_out);
> +	}
>  
>  	thread__put(sched_in);
>  
> @@ -3651,7 +3706,7 @@ int cmd_sched(int argc, const char **argv)
>  	OPT_STRING(0, "cpus", &sched.map.cpus_str, "cpus",
>                      "display given CPUs in map"),
>  	OPT_STRING(0, "task-name", &sched.map.task_name, "task",
> -		"map output only for the given task name"),
> +		"map output only for the given task name(s)."),
>  	OPT_PARENT(sched_options)
>  	};
>  	const struct option timehist_options[] = {
> -- 
> 2.43.2
>