Commit 549b92c9 authored by Tomas Glozar's avatar Tomas Glozar Committed by Steven Rostedt (Google)
Browse files

rtla/timerlat: Add --deepest-idle-state for top 

Add option to limit deepest idle state on CPUs where timerlat is running
for the duration of the workload.

Link: https://lore.kernel.org/20241017140914.3200454-5-tglozar@redhat.com


Signed-off-by: default avatarTomas Glozar <tglozar@redhat.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 083d29d3

tools/tracing/rtla/src/timerlat_top.c

+41 −1
Original line number Diff line number Diff line
@@ -48,6 +48,7 @@ struct timerlat_top_params { 
	int			pretty_output;

	int			warmup;

	int			buffer_size;

	int			deepest_idle_state;

	cpu_set_t		hk_cpu_set;

	struct sched_attr	sched_param;

	struct trace_events	*events;
@@ -447,7 +448,7 @@ static void timerlat_top_usage(char *usage) 
		"",

		"  usage: rtla timerlat [top] [-h] [-q] [-a us] [-d s] [-D] [-n] [-p us] [-i us] [-T us] [-s us] \\",

		"	  [[-t[file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] [-c cpu-list] [-H cpu-list]\\",

		"	  [-P priority] [--dma-latency us] [--aa-only us] [-C[=cgroup_name]] [-u|-k] [--warm-up s]",

		"	  [-P priority] [--dma-latency us] [--aa-only us] [-C[=cgroup_name]] [-u|-k] [--warm-up s] [--deepest-idle-state n]",

		"",

		"	  -h/--help: print this menu",

		"	  -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit",
@@ -481,6 +482,7 @@ static void timerlat_top_usage(char *usage) 
		"	  -U/--user-load: enable timerlat for user-defined user-space workload",

		"	     --warm-up s: let the workload run for s seconds before collecting data",

		"	     --trace-buffer-size kB: set the per-cpu trace buffer size in kB",

		"	     --deepest-idle-state n: only go down to idle state n on cpus used by timerlat to reduce exit from idle latency",

		NULL,

	};
@@ -518,6 +520,9 @@ static struct timerlat_top_params 
	/* disabled by default */

	params->dma_latency = -1;



	/* disabled by default */

	params->deepest_idle_state = -2;



	/* display data in microseconds */

	params->output_divisor = 1000;
@@ -550,6 +555,7 @@ static struct timerlat_top_params 
			{"aa-only",		required_argument,	0, '5'},

			{"warm-up",		required_argument,	0, '6'},

			{"trace-buffer-size",	required_argument,	0, '7'},

			{"deepest-idle-state",	required_argument,	0, '8'},

			{0, 0, 0, 0}

		};
@@ -726,6 +732,9 @@ static struct timerlat_top_params 
		case '7':

			params->buffer_size = get_llong_from_str(optarg);

			break;

		case '8':

			params->deepest_idle_state = get_llong_from_str(optarg);

			break;

		default:

			timerlat_top_usage("Invalid option");

		}
@@ -922,6 +931,7 @@ int timerlat_top_main(int argc, char *argv[]) 
	int return_value = 1;

	char *max_lat;

	int retval;

	int nr_cpus, i;



	params = timerlat_top_parse_args(argc, argv);

	if (!params)
@@ -971,6 +981,28 @@ int timerlat_top_main(int argc, char *argv[]) 
		}

	}



	if (params->deepest_idle_state >= -1) {

		if (!have_libcpupower_support()) {

			err_msg("rtla built without libcpupower, --deepest-idle-state is not supported\n");

			goto out_free;

		}



		nr_cpus = sysconf(_SC_NPROCESSORS_CONF);



		for (i = 0; i < nr_cpus; i++) {

			if (params->cpus && !CPU_ISSET(i, &params->monitored_cpus))

				continue;

			if (save_cpu_idle_disable_state(i) < 0) {

				err_msg("Could not save cpu idle state.\n");

				goto out_free;

			}

			if (set_deepest_cpu_idle_state(i, params->deepest_idle_state) < 0) {

				err_msg("Could not set deepest cpu idle state.\n");

				goto out_free;

			}

		}

	}



	if (params->trace_output) {

		record = osnoise_init_trace_tool("timerlat");

		if (!record) {
@@ -1125,6 +1157,13 @@ int timerlat_top_main(int argc, char *argv[]) 
	timerlat_aa_destroy();

	if (dma_latency_fd >= 0)

		close(dma_latency_fd);

	if (params->deepest_idle_state >= -1) {

		for (i = 0; i < nr_cpus; i++) {

			if (params->cpus && !CPU_ISSET(i, &params->monitored_cpus))

				continue;

			restore_cpu_idle_disable_state(i);

		}

	}

	trace_events_destroy(&record->trace, params->events);

	params->events = NULL;

out_free:
@@ -1134,6 +1173,7 @@ int timerlat_top_main(int argc, char *argv[]) 
	osnoise_destroy_tool(record);

	osnoise_destroy_tool(top);

	free(params);

	free_cpu_idle_disable_states();

out_exit:

	exit(return_value);

}