tools/rtla: Consolidate code between osnoise/timerlat and hist/top

Currently a lot of code is duplicated between the different rtla tools,
making maintenance more difficult, and encouraging divergence such as
features that are only implemented for certain tools even though they
could be more broadly applicable.

Merge the various main() functions into a common run_tool() with an ops
struct for tool-specific details.

Implement enough support for actions on osnoise to not need to keep the
old params->trace_output path.

Cc: John Kacur <jkacur@redhat.com>
Cc: Costa Shulyupin <costa.shul@redhat.com>
Link: https://lore.kernel.org/20250907022325.243930-5-crwood@redhat.com
Reviewed-by: Tomas Glozar  <tglozar@redhat.com>
Signed-off-by: Crystal Wood <crwood@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

1 files changed, 281 insertions, 0 deletions

diff --git a/tools/tracing/rtla/src/common.c b/tools/tracing/rtla/src/common.c
index 32a6faffc714..2e6e3dac1897 100644
--- a/tools/tracing/rtla/src/common.c
+++ b/tools/tracing/rtla/src/common.c
@@ -1,9 +1,42 @@
 // SPDX-License-Identifier: GPL-2.0
 #define _GNU_SOURCE
 
+#include <pthread.h>
+#include <signal.h>
+#include <stdlib.h>
 #include <unistd.h>
 #include "common.h"
 
+struct trace_instance *trace_inst;
+int stop_tracing;
+
+static void stop_trace(int sig)
+{
+	if (stop_tracing) {
+		/*
+		 * Stop requested twice in a row; abort event processing and
+		 * exit immediately
+		 */
+		tracefs_iterate_stop(trace_inst->inst);
+		return;
+	}
+	stop_tracing = 1;
+	if (trace_inst)
+		trace_instance_stop(trace_inst);
+}
+
+/*
+ * set_signals - handles the signal to stop the tool
+ */
+static void set_signals(struct common_params *params)
+{
+	signal(SIGINT, stop_trace);
+	if (params->duration) {
+		signal(SIGALRM, stop_trace);
+		alarm(params->duration);
+	}
+}
+
 /*
  * common_apply_config - apply common configs to the initialized tool
  */
@@ -61,3 +94,251 @@ out_err:
 	return -1;
 }
 
+
+int run_tool(struct tool_ops *ops, int argc, char *argv[])
+{
+	struct common_params *params;
+	enum result return_value = ERROR;
+	struct osnoise_tool *tool;
+	bool stopped;
+	int retval;
+
+	params = ops->parse_args(argc, argv);
+	if (!params)
+		exit(1);
+
+	tool = ops->init_tool(params);
+	if (!tool) {
+		err_msg("Could not init osnoise tool\n");
+		goto out_exit;
+	}
+	tool->ops = ops;
+	tool->params = params;
+
+	/*
+	 * Save trace instance into global variable so that SIGINT can stop
+	 * the timerlat tracer.
+	 * Otherwise, rtla could loop indefinitely when overloaded.
+	 */
+	trace_inst = &tool->trace;
+
+	retval = ops->apply_config(tool);
+	if (retval) {
+		err_msg("Could not apply config\n");
+		goto out_free;
+	}
+
+	retval = enable_tracer_by_name(trace_inst->inst, ops->tracer);
+	if (retval) {
+		err_msg("Failed to enable %s tracer\n", ops->tracer);
+		goto out_free;
+	}
+
+	if (params->set_sched) {
+		retval = set_comm_sched_attr(ops->comm_prefix, &params->sched_param);
+		if (retval) {
+			err_msg("Failed to set sched parameters\n");
+			goto out_free;
+		}
+	}
+
+	if (params->cgroup && !params->user_data) {
+		retval = set_comm_cgroup(ops->comm_prefix, params->cgroup_name);
+		if (!retval) {
+			err_msg("Failed to move threads to cgroup\n");
+			goto out_free;
+		}
+	}
+
+
+	if (params->threshold_actions.present[ACTION_TRACE_OUTPUT] ||
+	    params->end_actions.present[ACTION_TRACE_OUTPUT]) {
+		tool->record = osnoise_init_trace_tool(ops->tracer);
+		if (!tool->record) {
+			err_msg("Failed to enable the trace instance\n");
+			goto out_free;
+		}
+		params->threshold_actions.trace_output_inst = tool->record->trace.inst;
+		params->end_actions.trace_output_inst = tool->record->trace.inst;
+
+		if (params->events) {
+			retval = trace_events_enable(&tool->record->trace, params->events);
+			if (retval)
+				goto out_trace;
+		}
+
+		if (params->buffer_size > 0) {
+			retval = trace_set_buffer_size(&tool->record->trace, params->buffer_size);
+			if (retval)
+				goto out_trace;
+		}
+	}
+
+	if (params->user_workload) {
+		pthread_t user_thread;
+
+		/* rtla asked to stop */
+		params->user.should_run = 1;
+		/* all threads left */
+		params->user.stopped_running = 0;
+
+		params->user.set = &params->monitored_cpus;
+		if (params->set_sched)
+			params->user.sched_param = &params->sched_param;
+		else
+			params->user.sched_param = NULL;
+
+		params->user.cgroup_name = params->cgroup_name;
+
+		retval = pthread_create(&user_thread, NULL, timerlat_u_dispatcher, &params->user);
+		if (retval)
+			err_msg("Error creating timerlat user-space threads\n");
+	}
+
+	retval = ops->enable(tool);
+	if (retval)
+		goto out_trace;
+
+	tool->start_time = time(NULL);
+	set_signals(params);
+
+	retval = ops->main(tool);
+	if (retval)
+		goto out_trace;
+
+	if (params->user_workload && !params->user.stopped_running) {
+		params->user.should_run = 0;
+		sleep(1);
+	}
+
+	ops->print_stats(tool);
+
+	actions_perform(&params->end_actions);
+
+	return_value = PASSED;
+
+	stopped = osnoise_trace_is_off(tool, tool->record) && !stop_tracing;
+	if (stopped) {
+		printf("%s hit stop tracing\n", ops->tracer);
+		return_value = FAILED;
+	}
+
+	if (ops->analyze)
+		ops->analyze(tool, stopped);
+
+out_trace:
+	trace_events_destroy(&tool->record->trace, params->events);
+	params->events = NULL;
+out_free:
+	ops->free(tool);
+	osnoise_destroy_tool(tool->record);
+	osnoise_destroy_tool(tool);
+	actions_destroy(&params->threshold_actions);
+	actions_destroy(&params->end_actions);
+	free(params);
+out_exit:
+	exit(return_value);
+}
+
+int top_main_loop(struct osnoise_tool *tool)
+{
+	struct common_params *params = tool->params;
+	struct trace_instance *trace = &tool->trace;
+	struct osnoise_tool *record = tool->record;
+	int retval;
+
+	while (!stop_tracing) {
+		sleep(params->sleep_time);
+
+		if (params->aa_only && !osnoise_trace_is_off(tool, record))
+			continue;
+
+		retval = tracefs_iterate_raw_events(trace->tep,
+						    trace->inst,
+						    NULL,
+						    0,
+						    collect_registered_events,
+						    trace);
+		if (retval < 0) {
+			err_msg("Error iterating on events\n");
+			return retval;
+		}
+
+		if (!params->quiet)
+			tool->ops->print_stats(tool);
+
+		if (osnoise_trace_is_off(tool, record)) {
+			actions_perform(&params->threshold_actions);
+
+			if (!params->threshold_actions.continue_flag)
+				/* continue flag not set, break */
+				return 0;
+
+			/* continue action reached, re-enable tracing */
+			if (record)
+				trace_instance_start(&record->trace);
+			if (tool->aa)
+				trace_instance_start(&tool->aa->trace);
+			trace_instance_start(trace);
+		}
+
+		/* is there still any user-threads ? */
+		if (params->user_workload) {
+			if (params->user.stopped_running) {
+				debug_msg("timerlat user space threads stopped!\n");
+				break;
+			}
+		}
+	}
+
+	return 0;
+}
+
+int hist_main_loop(struct osnoise_tool *tool)
+{
+	struct common_params *params = tool->params;
+	struct trace_instance *trace = &tool->trace;
+	int retval = 0;
+
+	while (!stop_tracing) {
+		sleep(params->sleep_time);
+
+		retval = tracefs_iterate_raw_events(trace->tep,
+						    trace->inst,
+						    NULL,
+						    0,
+						    collect_registered_events,
+						    trace);
+		if (retval < 0) {
+			err_msg("Error iterating on events\n");
+			break;
+		}
+
+		if (osnoise_trace_is_off(tool, tool->record)) {
+			actions_perform(&params->threshold_actions);
+
+			if (!params->threshold_actions.continue_flag) {
+				/* continue flag not set, break */
+				break;
+
+				/* continue action reached, re-enable tracing */
+				if (tool->record)
+					trace_instance_start(&tool->record->trace);
+				if (tool->aa)
+					trace_instance_start(&tool->aa->trace);
+				trace_instance_start(&tool->trace);
+			}
+			break;
+		}
+
+		/* is there still any user-threads ? */
+		if (params->user_workload) {
+			if (params->user.stopped_running) {
+				debug_msg("user-space threads stopped!\n");
+				break;
+			}
+		}
+	}
+
+	return retval;
+}