rtla: Always set all tracer options

rtla currently only sets tracer options that are explicitly set by the
user, with the exception of OSNOISE_WORKLOAD.

This leads to improper behavior in case rtla is run with those options
not set to the default value. rtla does reset them to the original
value upon exiting, but that does not protect it from starting with
non-default values set either by an improperly exited rtla or by another
user of the tracers.

For example, after running this command:

$ echo 1 > /sys/kernel/tracing/osnoise/stop_tracing_us

all runs of rtla will stop at the 1us threshold, even if not requested
by the user:

$ rtla osnoise hist
Index   CPU-000   CPU-001
1             8         5
2             5         9
3             1         2
4             6         1
5             2         1
6             0         1
8             1         1
12            0         1
14            1         0
15            1         0
over:         0         0
count:       25        21
min:          1         1
avg:       3.68      3.05
max:         15        12
rtla osnoise hit stop tracing

Fix the problem by setting the default value for all tracer options if
the user has not provided their own value.

For most of the options, it's enough to just drop the if clause checking
for the value being set. For cpus, "all" is used as the default value,
and for osnoise default period and runtime, default values of
the osnoise_data variable in trace_osnoise.c are used.

Cc: Luis Goncalves <lgoncalv@redhat.com>
Link: https://lore.kernel.org/20250320092500.101385-5-tglozar@redhat.com
Fixes: 1eceb2fc2ca5 ("rtla/osnoise: Add osnoise top mode")
Fixes: 829a6c0b5698 ("rtla/osnoise: Add the hist mode")
Fixes: a828cd18bc4a ("rtla: Add timerlat tool and timelart top mode")
Fixes: 1eeb6328e8b3 ("rtla/timerlat: Add timerlat hist mode")
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Reviewed-by: John Kacur <jkacur@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/tools/tracing/rtla/src/osnoise.c b/tools/tracing/rtla/src/osnoise.c
index a71618d876e975d9d4de93e41f1ce1a7a1795b1f..2dc3e4539e99b4c1ac8eaf4cb6613dbf62f7228b 100644 (file)
--- a/tools/tracing/rtla/src/osnoise.c
+++ b/tools/tracing/rtla/src/osnoise.c
@@ -17,6 +17,9 @@
 
 #include "osnoise.h"
 
+#define DEFAULT_SAMPLE_PERIOD  1000000                 /* 1s */
+#define DEFAULT_SAMPLE_RUNTIME 1000000                 /* 1s */
+
 /*
  * osnoise_get_cpus - return the original "osnoise/cpus" content
  *
@@ -1127,46 +1130,43 @@ osnoise_apply_config(struct osnoise_tool *tool, struct osnoise_params *params)
        if (!params->sleep_time)
                params->sleep_time = 1;
 
-       if (params->cpus) {
-               retval = osnoise_set_cpus(tool->context, params->cpus);
-               if (retval) {
-                       err_msg("Failed to apply CPUs config\n");
-                       goto out_err;
-               }
+       retval = osnoise_set_cpus(tool->context, params->cpus ? params->cpus : "all");
+       if (retval) {
+               err_msg("Failed to apply CPUs config\n");
+               goto out_err;
        }
 
        if (params->runtime || params->period) {
                retval = osnoise_set_runtime_period(tool->context,
                                                    params->runtime,
                                                    params->period);
-               if (retval) {
-                       err_msg("Failed to set runtime and/or period\n");
-                       goto out_err;
-               }
+       } else {
+               retval = osnoise_set_runtime_period(tool->context,
+                                                   DEFAULT_SAMPLE_PERIOD,
+                                                   DEFAULT_SAMPLE_RUNTIME);
        }
 
-       if (params->stop_us) {
-               retval = osnoise_set_stop_us(tool->context, params->stop_us);
-               if (retval) {
-                       err_msg("Failed to set stop us\n");
-                       goto out_err;
-               }
+       if (retval) {
+               err_msg("Failed to set runtime and/or period\n");
+               goto out_err;
        }
 
-       if (params->stop_total_us) {
-               retval = osnoise_set_stop_total_us(tool->context, params->stop_total_us);
-               if (retval) {
-                       err_msg("Failed to set stop total us\n");
-                       goto out_err;
-               }
+       retval = osnoise_set_stop_us(tool->context, params->stop_us);
+       if (retval) {
+               err_msg("Failed to set stop us\n");
+               goto out_err;
        }
 
-       if (params->threshold) {
-               retval = osnoise_set_tracing_thresh(tool->context, params->threshold);
-               if (retval) {
-                       err_msg("Failed to set tracing_thresh\n");
-                       goto out_err;
-               }
+       retval = osnoise_set_stop_total_us(tool->context, params->stop_total_us);
+       if (retval) {
+               err_msg("Failed to set stop total us\n");
+               goto out_err;
+       }
+
+       retval = osnoise_set_tracing_thresh(tool->context, params->threshold);
+       if (retval) {
+               err_msg("Failed to set tracing_thresh\n");
+               goto out_err;
        }
 
        if (params->hk_cpus) {

diff --git a/tools/tracing/rtla/src/timerlat.c b/tools/tracing/rtla/src/timerlat.c
index 448fb1f7d3a6a4aa013d74b87c454bc568b2d18a..c29e2ba2d7d8fa7bbcc4ed4187b577f7f621c322 100644 (file)
--- a/tools/tracing/rtla/src/timerlat.c
+++ b/tools/tracing/rtla/src/timerlat.c
@@ -16,6 +16,8 @@
 
 #include "timerlat.h"
 
+#define DEFAULT_TIMERLAT_PERIOD        1000                    /* 1ms */
+
 /*
  * timerlat_apply_config - apply common configs to the initialized tool
  */
@@ -27,49 +29,44 @@ timerlat_apply_config(struct osnoise_tool *tool, struct timerlat_params *params)
        if (!params->sleep_time)
                params->sleep_time = 1;
 
-       if (params->cpus) {
-               retval = osnoise_set_cpus(tool->context, params->cpus);
-               if (retval) {
-                       err_msg("Failed to apply CPUs config\n");
-                       goto out_err;
-               }
-       } else {
+       retval = osnoise_set_cpus(tool->context, params->cpus ? params->cpus : "all");
+       if (retval) {
+               err_msg("Failed to apply CPUs config\n");
+               goto out_err;
+       }
+
+       if (!params->cpus) {
                for (i = 0; i < sysconf(_SC_NPROCESSORS_CONF); i++)
                        CPU_SET(i, &params->monitored_cpus);
        }
 
-       if (params->stop_us) {
-               retval = osnoise_set_stop_us(tool->context, params->stop_us);
-               if (retval) {
-                       err_msg("Failed to set stop us\n");
-                       goto out_err;
-               }
+       retval = osnoise_set_stop_us(tool->context, params->stop_us);
+       if (retval) {
+               err_msg("Failed to set stop us\n");
+               goto out_err;
        }
 
-       if (params->stop_total_us) {
-               retval = osnoise_set_stop_total_us(tool->context, params->stop_total_us);
-               if (retval) {
-                       err_msg("Failed to set stop total us\n");
-                       goto out_err;
-               }
+       retval = osnoise_set_stop_total_us(tool->context, params->stop_total_us);
+       if (retval) {
+               err_msg("Failed to set stop total us\n");
+               goto out_err;
        }
 
 
-       if (params->timerlat_period_us) {
-               retval = osnoise_set_timerlat_period_us(tool->context, params->timerlat_period_us);
-               if (retval) {
-                       err_msg("Failed to set timerlat period\n");
-                       goto out_err;
-               }
+       retval = osnoise_set_timerlat_period_us(tool->context,
+                                               params->timerlat_period_us ?
+                                               params->timerlat_period_us :
+                                               DEFAULT_TIMERLAT_PERIOD);
+       if (retval) {
+               err_msg("Failed to set timerlat period\n");
+               goto out_err;
        }
 
 
-       if (params->print_stack) {
-               retval = osnoise_set_print_stack(tool->context, params->print_stack);
-               if (retval) {
-                       err_msg("Failed to set print stack\n");
-                       goto out_err;
-               }
+       retval = osnoise_set_print_stack(tool->context, params->print_stack);
+       if (retval) {
+               err_msg("Failed to set print stack\n");
+               goto out_err;
        }
 
        if (params->hk_cpus) {