Commit a7e6b7dc authored by Tom Zanussi's avatar Tom Zanussi Committed by Steven Rostedt (Google)
Browse files

tracing: Separate hist state updates from hist registration 

hist_register_trigger() handles both new hist registration as well as
existing hist registration through event_command.reg().

Adding a new function, existing_hist_update_only(), that checks and
updates existing histograms and exits after doing so allows the
confusing logic in event_hist_trigger_parse() to be simplified.

Link: https://lkml.kernel.org/r/211b2cd3e3d7e00f4f8ad45ef8b33063da6a7e05.1644010576.git.zanussi@kernel.org



Signed-off-by: default avatarTom Zanussi <zanussi@kernel.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent e1f187d0

kernel/trace/trace_events_hist.c

+48 −18
Original line number Diff line number Diff line
@@ -5929,6 +5929,48 @@ static bool hist_trigger_match(struct event_trigger_data *data, 
	return true;

}



static bool existing_hist_update_only(char *glob,

				      struct event_trigger_data *data,

				      struct trace_event_file *file)

{

	struct hist_trigger_data *hist_data = data->private_data;

	struct event_trigger_data *test, *named_data = NULL;

	bool updated = false;



	if (!hist_data->attrs->pause && !hist_data->attrs->cont &&

	    !hist_data->attrs->clear)

		goto out;



	if (hist_data->attrs->name) {

		named_data = find_named_trigger(hist_data->attrs->name);

		if (named_data) {

			if (!hist_trigger_match(data, named_data, named_data,

						true))

				goto out;

		}

	}



	if (hist_data->attrs->name && !named_data)

		goto out;



	list_for_each_entry(test, &file->triggers, list) {

		if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {

			if (!hist_trigger_match(data, test, named_data, false))

				continue;

			if (hist_data->attrs->pause)

				test->paused = true;

			else if (hist_data->attrs->cont)

				test->paused = false;

			else if (hist_data->attrs->clear)

				hist_clear(test);

			updated = true;

			goto out;

		}

	}

 out:

	return updated;

}



static int hist_register_trigger(char *glob,

				 struct event_trigger_data *data,

				 struct trace_event_file *file)
@@ -5957,21 +5999,13 @@ static int hist_register_trigger(char *glob, 


	list_for_each_entry(test, &file->triggers, list) {

		if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {

			if (!hist_trigger_match(data, test, named_data, false))

				continue;

			if (hist_data->attrs->pause)

				test->paused = true;

			else if (hist_data->attrs->cont)

				test->paused = false;

			else if (hist_data->attrs->clear)

				hist_clear(test);

			else {

			if (hist_trigger_match(data, test, named_data, false)) {

				hist_err(tr, HIST_ERR_TRIGGER_EEXIST, 0);

				ret = -EEXIST;

			}

				goto out;

			}

		}

	}

 new:

	if (hist_data->attrs->cont || hist_data->attrs->clear) {

		hist_err(tr, HIST_ERR_TRIGGER_ENOENT_CLEAR, 0);
@@ -6008,8 +6042,6 @@ static int hist_register_trigger(char *glob, 


	if (named_data)

		destroy_hist_data(hist_data);



	ret++;

 out:

	return ret;

}
@@ -6277,14 +6309,12 @@ static int event_hist_trigger_parse(struct event_command *cmd_ops, 
		goto out_free;

	}



	ret = event_trigger_register(cmd_ops, file, glob, trigger_data);

	if (ret)

	if (existing_hist_update_only(glob, trigger_data, file))

		goto out_free;

	if (ret == 0) {

		if (!(attrs->pause || attrs->cont || attrs->clear))

			ret = -ENOENT;



	ret = event_trigger_register(cmd_ops, file, glob, trigger_data);

	if (ret < 0)

		goto out_free;

	}



	if (get_named_trigger_data(trigger_data))

		goto enable;