[PATCH v2 5/9] rtla/timerlat: Add action on end feature

Tomas Glozar
2025-06-26T12:36:26Z

Implement actions on end next to actions on threshold. A new option,
--on-end is added, parallel to --on-threshold. Instead of being
executed whenever a latency threshold is reached, it is executed at the
end of the measurement.

For example:

$ rtla timerlat hist -d 5s --on-end trace

will save the trace output at the end.

All actions supported by --on-threshold are also supported by --on-end,
except for continue, which does nothing with --on-end.

Signed-off-by: Tomas Glozar <tglozar@redhat.com>
---
tools/tracing/rtla/src/timerlat.h | 5 ++-
tools/tracing/rtla/src/timerlat_hist.c | 44 +++++++++++++++++--------
tools/tracing/rtla/src/timerlat_top.c | 45 ++++++++++++++++++--------
3 files changed, 65 insertions(+), 29 deletions(-)

diff --git a/tools/tracing/rtla/src/timerlat.h b/tools/tracing/rtla/src/timerlat.h
index d1fcf9a97621..bc55ed04fc96 100644
--- a/tools/tracing/rtla/src/timerlat.h
+++ b/tools/tracing/rtla/src/timerlat.h
@@ -48,7 +48,10 @@ struct timerlat_params {
struct sched_attr sched_param;
struct trace_events *events;
enum timerlat_tracing_mode mode;
- struct actions actions;
+
+ struct actions threshold_actions;
+ struct actions end_actions;
+
union {
struct {
/* top only */
diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index 4f13a8f92711..9baea1b251ed 100644
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -758,6 +758,7 @@ static void timerlat_hist_usage(char *usage)
" --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",
" --on-threshold <action>: define action to be executed at latency threshold, multiple are allowed",
+ " --on-end <action>: define action to be executed at measurement end, multiple are allowed",
NULL,
};

@@ -793,7 +794,8 @@ static struct timerlat_params
if (!params)
exit(1);

- actions_init(&params->actions);
+ actions_init(&params->threshold_actions);
+ actions_init(&params->end_actions);

/* disabled by default */
params->dma_latency = -1;
@@ -846,6 +848,7 @@ static struct timerlat_params
{"trace-buffer-size", required_argument, 0, '\3'},
{"deepest-idle-state", required_argument, 0, '\4'},
{"on-threshold", required_argument, 0, '\5'},
+ {"on-end", required_argument, 0, '\6'},
{0, 0, 0, 0}
};

@@ -1038,7 +1041,14 @@ static struct timerlat_params
params->deepest_idle_state = get_llong_from_str(optarg);
break;
case '\5':
- retval = actions_parse(&params->actions, optarg);
+ retval = actions_parse(&params->threshold_actions, optarg);
+ if (retval) {
+ err_msg("Invalid action %s\n", optarg);
+ exit(EXIT_FAILURE);
+ }
+ break;
+ case '\6':
+ retval = actions_parse(&params->end_actions, optarg);
if (retval) {
err_msg("Invalid action %s\n", optarg);
exit(EXIT_FAILURE);
@@ -1050,7 +1060,7 @@ static struct timerlat_params
}

if (trace_output)
- actions_add_trace_output(&params->actions, trace_output);
+ actions_add_trace_output(&params->threshold_actions, trace_output);

if (geteuid()) {
err_msg("rtla needs root permission\n");
@@ -1077,7 +1087,8 @@ static struct timerlat_params
* mixed mode
*/
if (params->mode == TRACING_MODE_BPF &&
- (params->actions.present[ACTION_TRACE_OUTPUT] || !params->no_aa))
+ (params->threshold_actions.present[ACTION_TRACE_OUTPUT] ||
+ params->end_actions.present[ACTION_TRACE_OUTPUT] || !params->no_aa))
params->mode = TRACING_MODE_MIXED;

return params;
@@ -1270,13 +1281,15 @@ int timerlat_hist_main(int argc, char *argv[])
}
}

- if (params->actions.present[ACTION_TRACE_OUTPUT]) {
+ if (params->threshold_actions.present[ACTION_TRACE_OUTPUT] ||
+ params->end_actions.present[ACTION_TRACE_OUTPUT]) {
record = osnoise_init_trace_tool("timerlat");
if (!record) {
err_msg("Failed to enable the trace instance\n");
goto out_free;
}
- params->actions.trace_output_inst = record->trace.inst;
+ params->threshold_actions.trace_output_inst = record->trace.inst;
+ params->end_actions.trace_output_inst = record->trace.inst;

if (params->events) {
retval = trace_events_enable(&record->trace, params->events);
@@ -1342,7 +1355,7 @@ int timerlat_hist_main(int argc, char *argv[])
* tracing while enabling other instances. The trace instance is the
* one with most valuable information.
*/
- if (params->actions.present[ACTION_TRACE_OUTPUT])
+ if (record)
trace_instance_start(&record->trace);
if (!params->no_aa)
trace_instance_start(&aa->trace);
@@ -1375,14 +1388,14 @@ int timerlat_hist_main(int argc, char *argv[])
}

if (osnoise_trace_is_off(tool, record)) {
- actions_perform(&params->actions);
+ actions_perform(&params->threshold_actions);

- if (!params->actions.continue_flag)
+ if (!params->threshold_actions.continue_flag)
/* continue flag not set, break */
break;

/* continue action reached, re-enable tracing */
- if (params->actions.present[ACTION_TRACE_OUTPUT])
+ if (record)
trace_instance_start(&record->trace);
if (!params->no_aa)
trace_instance_start(&aa->trace);
@@ -1403,14 +1416,14 @@ int timerlat_hist_main(int argc, char *argv[])

if (!stop_tracing) {
/* Threshold overflow, perform actions on threshold */
- actions_perform(&params->actions);
+ actions_perform(&params->threshold_actions);

- if (!params->actions.continue_flag)
+ if (!params->threshold_actions.continue_flag)
/* continue flag not set, break */
break;

/* continue action reached, re-enable tracing */
- if (params->actions.present[ACTION_TRACE_OUTPUT])
+ if (record)
trace_instance_start(&record->trace);
if (!params->no_aa)
trace_instance_start(&aa->trace);
@@ -1435,6 +1448,8 @@ int timerlat_hist_main(int argc, char *argv[])

timerlat_print_stats(params, tool);

+ actions_perform(&params->end_actions);
+
return_value = PASSED;

if (osnoise_trace_is_off(tool, record) && !stop_tracing) {
@@ -1464,7 +1479,8 @@ int timerlat_hist_main(int argc, char *argv[])
osnoise_destroy_tool(aa);
osnoise_destroy_tool(record);
osnoise_destroy_tool(tool);
- actions_destroy(&params->actions);
+ actions_destroy(&params->threshold_actions);
+ actions_destroy(&params->end_actions);
if (params->mode != TRACING_MODE_TRACEFS)
timerlat_bpf_destroy();
free(params);
diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
index 60f9c78cb272..c80b81c0b4da 100644
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -517,6 +517,7 @@ static void timerlat_top_usage(char *usage)
" --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",
" --on-threshold <action>: define action to be executed at latency threshold, multiple are allowed",
+ " --on-end: define action to be executed at measurement end, multiple are allowed",
NULL,
};

@@ -552,7 +553,8 @@ static struct timerlat_params
if (!params)
exit(1);

- actions_init(&params->actions);
+ actions_init(&params->threshold_actions);
+ actions_init(&params->end_actions);

/* disabled by default */
params->dma_latency = -1;
@@ -597,6 +599,7 @@ static struct timerlat_params
{"trace-buffer-size", required_argument, 0, '7'},
{"deepest-idle-state", required_argument, 0, '8'},
{"on-threshold", required_argument, 0, '9'},
+ {"on-end", required_argument, 0, '\1'},
{0, 0, 0, 0}
};

@@ -623,6 +626,7 @@ static struct timerlat_params

/* set trace */
trace_output = "timerlat_trace.txt";
+
break;
case '5':
/* it is here because it is similar to -a */
@@ -776,7 +780,14 @@ static struct timerlat_params
params->deepest_idle_state = get_llong_from_str(optarg);
break;
case '9':
- retval = actions_parse(&params->actions, optarg);
+ retval = actions_parse(&params->threshold_actions, optarg);
+ if (retval) {
+ err_msg("Invalid action %s\n", optarg);
+ exit(EXIT_FAILURE);
+ }
+ break;
+ case '\1':
+ retval = actions_parse(&params->end_actions, optarg);
if (retval) {
err_msg("Invalid action %s\n", optarg);
exit(EXIT_FAILURE);
@@ -788,7 +799,7 @@ static struct timerlat_params
}

if (trace_output)
- actions_add_trace_output(&params->actions, trace_output);
+ actions_add_trace_output(&params->threshold_actions, trace_output);

if (geteuid()) {
err_msg("rtla needs root permission\n");
@@ -812,7 +823,8 @@ static struct timerlat_params
* mixed mode
*/
if (params->mode == TRACING_MODE_BPF &&
- (params->actions.present[ACTION_TRACE_OUTPUT] || !params->no_aa))
+ (params->threshold_actions.present[ACTION_TRACE_OUTPUT] ||
+ params->end_actions.present[ACTION_TRACE_OUTPUT] || !params->no_aa))
params->mode = TRACING_MODE_MIXED;

return params;
@@ -934,14 +946,14 @@ timerlat_top_main_loop(struct osnoise_tool *top,
timerlat_print_stats(params, top);

if (osnoise_trace_is_off(top, record)) {
- actions_perform(&params->actions);
+ actions_perform(&params->threshold_actions);

- if (!params->actions.continue_flag)
+ if (!params->threshold_actions.continue_flag)
/* continue flag not set, break */
break;

/* continue action reached, re-enable tracing */
- if (params->actions.present[ACTION_TRACE_OUTPUT])
+ if (record)
trace_instance_start(&record->trace);
if (!params->no_aa)
trace_instance_start(&aa->trace);
@@ -993,14 +1005,14 @@ timerlat_top_bpf_main_loop(struct osnoise_tool *top,

if (wait_retval == 1) {
/* Stopping requested by tracer */
- actions_perform(&params->actions);
+ actions_perform(&params->threshold_actions);

- if (!params->actions.continue_flag)
+ if (!params->threshold_actions.continue_flag)
/* continue flag not set, break */
break;

/* continue action reached, re-enable tracing */
- if (params->actions.present[ACTION_TRACE_OUTPUT])
+ if (record)
trace_instance_start(&record->trace);
if (!params->no_aa)
trace_instance_start(&aa->trace);
@@ -1128,13 +1140,15 @@ int timerlat_top_main(int argc, char *argv[])
}
}

- if (params->actions.present[ACTION_TRACE_OUTPUT]) {
+ if (params->threshold_actions.present[ACTION_TRACE_OUTPUT] ||
+ params->end_actions.present[ACTION_TRACE_OUTPUT]) {
record = osnoise_init_trace_tool("timerlat");
if (!record) {
err_msg("Failed to enable the trace instance\n");
goto out_free;
}
- params->actions.trace_output_inst = record->trace.inst;
+ params->threshold_actions.trace_output_inst = record->trace.inst;
+ params->end_actions.trace_output_inst = record->trace.inst;

if (params->events) {
retval = trace_events_enable(&record->trace, params->events);
@@ -1201,7 +1215,7 @@ int timerlat_top_main(int argc, char *argv[])
* tracing while enabling other instances. The trace instance is the
* one with most valuable information.
*/
- if (params->actions.present[ACTION_TRACE_OUTPUT])
+ if (record)
trace_instance_start(&record->trace);
if (!params->no_aa)
trace_instance_start(&aa->trace);
@@ -1236,6 +1250,8 @@ int timerlat_top_main(int argc, char *argv[])

timerlat_print_stats(params, top);

+ actions_perform(&params->end_actions);
+
return_value = PASSED;

if (osnoise_trace_is_off(top, record) && !stop_tracing) {
@@ -1276,7 +1292,8 @@ int timerlat_top_main(int argc, char *argv[])
osnoise_destroy_tool(aa);
osnoise_destroy_tool(record);
osnoise_destroy_tool(top);
- actions_destroy(&params->actions);
+ actions_destroy(&params->threshold_actions);
+ actions_destroy(&params->end_actions);
if (params->mode != TRACING_MODE_TRACEFS)
timerlat_bpf_destroy();
free(params);
--
2.49.0