Commit 2091336b authored by Daniel Bristot de Oliveira's avatar Daniel Bristot de Oliveira Committed by Steven Rostedt (Google)
Browse files

rtla/timerlat_hist: Add auto-analysis support 

Add auto-analysis to timerlat hist, including the --no-aa option to
reduce overhead and --dump-task. --aa-only was not added as it is
already on timerlat top.

Link: https://lkml.kernel.org/r/c2693f47ee83e659a7723fed8035f5d2534f528e.1686066600.git.bristot@kernel.org



Cc: William White <chwhite@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Tested-by: default avatarJuri Lelli <juri.lelli@redhat.com>
Signed-off-by: default avatarDaniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent c66552be

Documentation/tools/rtla/common_timerlat_aa.rst

+0 −7
Original line number Diff line number Diff line
@@ -5,10 +5,3 @@ 
**--no-aa**



        disable auto-analysis, reducing rtla timerlat cpu usage
 


**--aa-only** *us*



        Set stop tracing conditions and run without collecting and displaying statistics.

        Print the auto-analysis if the system hits the stop tracing condition. This option

        is useful to reduce rtla timerlat CPU, enabling the debug without the overhead of

        collecting the statistics.

Documentation/tools/rtla/rtla-timerlat-hist.rst

+5 −2
Original line number Diff line number Diff line
@@ -29,15 +29,18 @@ OPTIONS 


.. include:: common_options.rst



.. include:: common_timerlat_aa.rst



EXAMPLE

=======

In the example below, **rtla timerlat hist** is set to run for *10* minutes,

in the cpus *0-4*, *skipping zero* only lines. Moreover, **rtla timerlat

hist** will change the priority of the *timerlat* threads to run under

*SCHED_DEADLINE* priority, with a *10us* runtime every *1ms* period. The

*1ms* period is also passed to the *timerlat* tracer::

*1ms* period is also passed to the *timerlat* tracer. Auto-analysis is disabled

to reduce overhead ::



  [root@alien ~]# timerlat hist -d 10m -c 0-4 -P d:100us:1ms -p 1ms

  [root@alien ~]# timerlat hist -d 10m -c 0-4 -P d:100us:1ms -p 1ms --no-aa

  # RTLA timerlat histogram

  # Time unit is microseconds (us)

  # Duration:   0 00:10:00

Documentation/tools/rtla/rtla-timerlat-top.rst

+7 −0
Original line number Diff line number Diff line
@@ -32,6 +32,13 @@ OPTIONS 


.. include:: common_timerlat_aa.rst



**--aa-only** *us*



        Set stop tracing conditions and run without collecting and displaying statistics.

        Print the auto-analysis if the system hits the stop tracing condition. This option

        is useful to reduce rtla timerlat CPU, enabling the debug without the overhead of

        collecting the statistics.



EXAMPLE

=======

tools/tracing/rtla/src/timerlat_hist.c

+49 −2
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include "utils.h"

#include "osnoise.h"

#include "timerlat.h"

#include "timerlat_aa.h"



struct timerlat_hist_params {

	char			*cpus;
@@ -34,6 +35,8 @@ struct timerlat_hist_params { 
	int			dma_latency;

	int			cgroup;

	int			hk_cpus;

	int			no_aa;

	int			dump_tasks;

	cpu_set_t		hk_cpu_set;

	struct sched_attr	sched_param;

	struct trace_events	*events;
@@ -438,7 +441,7 @@ static void timerlat_hist_usage(char *usage) 
		"  usage: [rtla] timerlat hist [-h] [-q] [-d s] [-D] [-n] [-a us] [-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] [-E N] [-b N] [--no-irq] [--no-thread] [--no-header] [--no-summary] \\",

		"	  [--no-index] [--with-zeros] [--dma-latency us] [-C[=cgroup_name]]",

		"	  [--no-index] [--with-zeros] [--dma-latency us] [-C[=cgroup_name]] [--no-aa] [--dump-task]",

		"",

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

		"	  -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit",
@@ -450,12 +453,14 @@ static void timerlat_hist_usage(char *usage) 
		"	  -H/--house-keeping cpus: run rtla control threads only on the given cpus",

		"	  -C/--cgroup[=cgroup_name]: set cgroup, if no cgroup_name is passed, the rtla's cgroup will be inherited",

		"	  -d/--duration time[m|h|d]: duration of the session in seconds",

		"	     --dump-tasks: prints the task running on all CPUs if stop conditions are met (depends on !--no-aa)",

		"	  -D/--debug: print debug info",

		"	  -t/--trace[=file]: save the stopped trace to [file|timerlat_trace.txt]",

		"	  -e/--event <sys:event>: enable the <sys:event> in the trace instance, multiple -e are allowed",

		"	     --filter <filter>: enable a trace event filter to the previous -e event",

		"	     --trigger <trigger>: enable a trace event trigger to the previous -e event",

		"	  -n/--nano: display data in nanoseconds",

		"	     --no-aa: disable auto-analysis, reducing rtla timerlat cpu usage",

		"	  -b/--bucket-size N: set the histogram bucket size (default 1)",

		"	  -E/--entries N: set the number of entries of the histogram (default 256)",

		"	     --no-irq: ignore IRQ latencies",
@@ -537,13 +542,15 @@ static struct timerlat_hist_params 
			{"trigger",		required_argument,	0, '6'},

			{"filter",		required_argument,	0, '7'},

			{"dma-latency",		required_argument,	0, '8'},

			{"no-aa",		no_argument,		0, '9'},

			{"dump-task",		no_argument,		0, '\1'},

			{0, 0, 0, 0}

		};



		/* getopt_long stores the option index here. */

		int option_index = 0;



		c = getopt_long(argc, argv, "a:c:C::b:d:e:E:DhH:i:np:P:s:t::T:0123456:7:8:",

		c = getopt_long(argc, argv, "a:c:C::b:d:e:E:DhH:i:np:P:s:t::T:0123456:7:8:9\1",

				 long_options, &option_index);



		/* detect the end of the options. */
@@ -556,6 +563,7 @@ static struct timerlat_hist_params 


			/* set thread stop to auto_thresh */

			params->stop_total_us = auto_thresh;

			params->stop_us = auto_thresh;



			/* get stack trace */

			params->print_stack = auto_thresh;
@@ -699,6 +707,12 @@ static struct timerlat_hist_params 
				exit(EXIT_FAILURE);

			}

			break;

		case '9':

			params->no_aa = 1;

			break;

		case '\1':

			params->dump_tasks = 1;

			break;

		default:

			timerlat_hist_usage("Invalid option");

		}
@@ -715,6 +729,12 @@ static struct timerlat_hist_params 
	if (params->no_index && !params->with_zeros)

		timerlat_hist_usage("no-index set with with-zeros is not set - it does not make sense");



	/*

	 * Auto analysis only happens if stop tracing, thus:

	 */

	if (!params->stop_us && !params->stop_total_us)

		params->no_aa = 1;



	return params;

}
@@ -848,6 +868,7 @@ int timerlat_hist_main(int argc, char *argv[]) 
	struct timerlat_hist_params *params;

	struct osnoise_tool *record = NULL;

	struct osnoise_tool *tool = NULL;

	struct osnoise_tool *aa = NULL;

	struct trace_instance *trace;

	int dma_latency_fd = -1;

	int return_value = 1;
@@ -919,6 +940,26 @@ int timerlat_hist_main(int argc, char *argv[]) 
		trace_instance_start(&record->trace);

	}



	if (!params->no_aa) {

		aa = osnoise_init_tool("timerlat_aa");

		if (!aa)

			goto out_hist;



		retval = timerlat_aa_init(aa, params->dump_tasks);

		if (retval) {

			err_msg("Failed to enable the auto analysis instance\n");

			goto out_hist;

		}



		retval = enable_timerlat(&aa->trace);

		if (retval) {

			err_msg("Failed to enable timerlat tracer\n");

			goto out_hist;

		}



		trace_instance_start(&aa->trace);

	}



	tool->start_time = time(NULL);

	timerlat_hist_set_signals(params);
@@ -946,6 +987,10 @@ int timerlat_hist_main(int argc, char *argv[]) 


	if (trace_is_off(&tool->trace, &record->trace)) {

		printf("rtla timerlat hit stop tracing\n");



		if (!params->no_aa)

			timerlat_auto_analysis(params->stop_us, params->stop_total_us);



		if (params->trace_output) {

			printf("  Saving trace to %s\n", params->trace_output);

			save_trace_to_file(record->trace.inst, params->trace_output);
@@ -953,12 +998,14 @@ int timerlat_hist_main(int argc, char *argv[]) 
	}



out_hist:

	timerlat_aa_destroy();

	if (dma_latency_fd >= 0)

		close(dma_latency_fd);

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

	params->events = NULL;

out_free:

	timerlat_free_histogram(tool->data);

	osnoise_destroy_tool(aa);

	osnoise_destroy_tool(record);

	osnoise_destroy_tool(tool);

	free(params);