rtla: Add the --warm-up option

On many cases, the results right after the startup are different
from the rest of the execution, biasing the results. For example,
on osnoise, the scheduler might take some time to adapt to the new
busy-loop workload.

Add the --warm-up <seconds> option, adding a warm-up phase (in
seconds) where the workload is set, but the results are discarded.

Link: https://lkml.kernel.org/r/e682d5ce5af90f123bd13220f63d5c3d118a92be.1713968967.git.bristot@kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>

diff --git a/Documentation/tools/rtla/common_options.rst b/Documentation/tools/rtla/common_options.rst
index aeb91ff3bd68cbc8166a3e8781250038a10a5e74..a96ea0ed662ef4c37e252ba8ae308ed69dacf720 100644 (file)
--- a/Documentation/tools/rtla/common_options.rst
+++ b/Documentation/tools/rtla/common_options.rst
@@ -50,6 +50,10 @@
 
         Set a *cgroup* to the tracer's threads. If the **-C** option is passed without arguments, the tracer's thread will inherit **rtla**'s *cgroup*. Otherwise, the threads will be placed on the *cgroup* passed to the option.
 
+**--warm-up** *s*
+
+        After starting the workload, let it run for *s* seconds before starting collecting the data, allowing the system to warm-up. Statistical data generated during warm-up is discarded.
+
 **-h**, **--help**
 
         Print help menu.

diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c
index 01870d50942a19a242f6444c7b11f019b460ec4e..c6100ff46a7f06a37cfa5c23662995fd85262c7f 100644 (file)
--- a/tools/tracing/rtla/src/osnoise_hist.c
+++ b/tools/tracing/rtla/src/osnoise_hist.c
@@ -36,13 +36,13 @@ struct osnoise_hist_params {
        cpu_set_t               hk_cpu_set;
        struct sched_attr       sched_param;
        struct trace_events     *events;
-
        char                    no_header;
        char                    no_summary;
        char                    no_index;
        char                    with_zeros;
        int                     bucket_size;
        int                     entries;
+       int                     warmup;
 };
 
 struct osnoise_hist_cpu {
@@ -438,7 +438,7 @@ static void osnoise_hist_usage(char *usage)
                "  usage: rtla osnoise hist [-h] [-D] [-d s] [-a us] [-p us] [-r us] [-s us] [-S us] \\",
                "         [-T us] [-t[=file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] \\",
                "         [-c cpu-list] [-H cpu-list] [-P priority] [-b N] [-E N] [--no-header] [--no-summary] \\",
-               "         [--no-index] [--with-zeros] [-C[=cgroup_name]]",
+               "         [--no-index] [--with-zeros] [-C[=cgroup_name]] [--warm-up]",
                "",
                "         -h/--help: print this menu",
                "         -a/--auto: set automatic trace mode, stopping the session if argument in us sample is hit",
@@ -468,6 +468,7 @@ static void osnoise_hist_usage(char *usage)
                "               f:prio - use SCHED_FIFO with prio",
                "               d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period",
                "                                                      in nanoseconds",
+               "            --warm-up: let the workload run for s seconds before collecting data",
                NULL,
        };
 
@@ -531,13 +532,14 @@ static struct osnoise_hist_params
                        {"with-zeros",          no_argument,            0, '3'},
                        {"trigger",             required_argument,      0, '4'},
                        {"filter",              required_argument,      0, '5'},
+                       {"warm-up",             required_argument,      0, '6'},
                        {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:p:P:r:s:S:t::T:01234:5:",
+               c = getopt_long(argc, argv, "a:c:C::b:d:e:E:DhH:p:P:r:s:S:t::T:01234:5:6:",
                                 long_options, &option_index);
 
                /* detect the end of the options. */
@@ -680,6 +682,9 @@ static struct osnoise_hist_params
                                osnoise_hist_usage("--filter requires a previous -e\n");
                        }
                        break;
+               case '6':
+                       params->warmup = get_llong_from_str(optarg);
+                       break;
                default:
                        osnoise_hist_usage("Invalid option");
                }
@@ -899,6 +904,25 @@ int osnoise_hist_main(int argc, char *argv[])
                trace_instance_start(&record->trace);
        trace_instance_start(trace);
 
+       if (params->warmup > 0) {
+               debug_msg("Warming up for %d seconds\n", params->warmup);
+               sleep(params->warmup);
+               if (stop_tracing)
+                       goto out_hist;
+
+               /*
+                * Clean up the buffer. The osnoise workload do not run
+                * with tracing off to avoid creating a performance penalty
+                * when not needed.
+                */
+               retval = tracefs_instance_file_write(trace->inst, "trace", "");
+               if (retval < 0) {
+                       debug_msg("Error cleaning up the buffer");
+                       goto out_hist;
+               }
+
+       }
+
        tool->start_time = time(NULL);
        osnoise_hist_set_signals(params);
 

diff --git a/tools/tracing/rtla/src/osnoise_top.c b/tools/tracing/rtla/src/osnoise_top.c
index 457360db07673191fbc034c9fdb3193b91c4499c..53a074c1222e33208483c7a181436b504dc1ecf2 100644 (file)
--- a/tools/tracing/rtla/src/osnoise_top.c
+++ b/tools/tracing/rtla/src/osnoise_top.c
@@ -40,6 +40,7 @@ struct osnoise_top_params {
        int                     set_sched;
        int                     cgroup;
        int                     hk_cpus;
+       int                     warmup;
        cpu_set_t               hk_cpu_set;
        struct sched_attr       sched_param;
        struct trace_events     *events;
@@ -282,7 +283,7 @@ static void osnoise_top_usage(struct osnoise_top_params *params, char *usage)
        static const char * const msg[] = {
                " [-h] [-q] [-D] [-d s] [-a us] [-p us] [-r us] [-s us] [-S us] \\",
                "         [-T us] [-t[=file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] \\",
-               "         [-c cpu-list] [-H cpu-list] [-P priority] [-C[=cgroup_name]]",
+               "         [-c cpu-list] [-H cpu-list] [-P priority] [-C[=cgroup_name]] [--warm-up s]",
                "",
                "         -h/--help: print this menu",
                "         -a/--auto: set automatic trace mode, stopping the session if argument in us sample is hit",
@@ -307,6 +308,7 @@ static void osnoise_top_usage(struct osnoise_top_params *params, char *usage)
                "               f:prio - use SCHED_FIFO with prio",
                "               d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period",
                "                                                      in nanoseconds",
+               "            --warm-up s: let the workload run for s seconds before collecting data",
                NULL,
        };
 
@@ -381,13 +383,14 @@ struct osnoise_top_params *osnoise_top_parse_args(int argc, char **argv)
                        {"trace",               optional_argument,      0, 't'},
                        {"trigger",             required_argument,      0, '0'},
                        {"filter",              required_argument,      0, '1'},
+                       {"warm-up",             required_argument,      0, '2'},
                        {0, 0, 0, 0}
                };
 
                /* getopt_long stores the option index here. */
                int option_index = 0;
 
-               c = getopt_long(argc, argv, "a:c:C::d:De:hH:p:P:qr:s:S:t::T:0:1:",
+               c = getopt_long(argc, argv, "a:c:C::d:De:hH:p:P:qr:s:S:t::T:0:1:2:",
                                 long_options, &option_index);
 
                /* Detect the end of the options. */
@@ -511,6 +514,9 @@ struct osnoise_top_params *osnoise_top_parse_args(int argc, char **argv)
                                osnoise_top_usage(params, "--filter requires a previous -e\n");
                        }
                        break;
+               case '2':
+                       params->warmup = get_llong_from_str(optarg);
+                       break;
                default:
                        osnoise_top_usage(params, "Invalid option");
                }
@@ -732,6 +738,25 @@ int osnoise_top_main(int argc, char **argv)
                trace_instance_start(&record->trace);
        trace_instance_start(trace);
 
+       if (params->warmup > 0) {
+               debug_msg("Warming up for %d seconds\n", params->warmup);
+               sleep(params->warmup);
+               if (stop_tracing)
+                       goto out_top;
+
+               /*
+                * Clean up the buffer. The osnoise workload do not run
+                * with tracing off to avoid creating a performance penalty
+                * when not needed.
+                */
+               retval = tracefs_instance_file_write(trace->inst, "trace", "");
+               if (retval < 0) {
+                       debug_msg("Error cleaning up the buffer");
+                       goto out_top;
+               }
+
+       }
+
        tool->start_time = time(NULL);
        osnoise_top_set_signals(params);
 

diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index b12c6b571dd4673c316b8f9db33e391d342549e2..da1c353bdac9d67c40e7bc78c4e71856557e33da 100644 (file)
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -52,6 +52,7 @@ struct timerlat_hist_params {
        char                    with_zeros;
        int                     bucket_size;
        int                     entries;
+       int                     warmup;
 };
 
 struct timerlat_hist_cpu {
@@ -628,6 +629,7 @@ static void timerlat_hist_usage(char *usage)
                "         [-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-aa] [--dump-task] [-u]",
+               "         [--warm-up s]",
                "",
                "         -h/--help: print this menu",
                "         -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit",
@@ -664,6 +666,7 @@ static void timerlat_hist_usage(char *usage)
                "                                                      in nanoseconds",
                "         -u/--user-threads: use rtla user-space threads instead of in-kernel timerlat threads",
                "         -U/--user-load: enable timerlat for user-defined user-space workload",
+               "            --warm-up s: let the workload run for s seconds before collecting data",
                NULL,
        };
 
@@ -738,13 +741,14 @@ static struct timerlat_hist_params
                        {"dma-latency",         required_argument,      0, '8'},
                        {"no-aa",               no_argument,            0, '9'},
                        {"dump-task",           no_argument,            0, '\1'},
+                       {"warm-up",             required_argument,      0, '\2'},
                        {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:uU0123456:7:8:9\1",
+               c = getopt_long(argc, argv, "a:c:C::b:d:e:E:DhH:i:np:P:s:t::T:uU0123456:7:8:9\1\2:",
                                 long_options, &option_index);
 
                /* detect the end of the options. */
@@ -913,6 +917,9 @@ static struct timerlat_hist_params
                case '\1':
                        params->dump_tasks = 1;
                        break;
+               case '\2':
+                       params->warmup = get_llong_from_str(optarg);
+                       break;
                default:
                        timerlat_hist_usage("Invalid option");
                }
@@ -1167,22 +1174,6 @@ int timerlat_hist_main(int argc, char *argv[])
                }
        }
 
-       /*
-        * Start the tracers here, after having set all instances.
-        *
-        * Let the trace instance start first for the case of hitting a stop
-        * tracing while enabling other instances. The trace instance is the
-        * one with most valuable information.
-        */
-       if (params->trace_output)
-               trace_instance_start(&record->trace);
-       if (!params->no_aa)
-               trace_instance_start(&aa->trace);
-       trace_instance_start(trace);
-
-       tool->start_time = time(NULL);
-       timerlat_hist_set_signals(params);
-
        if (params->user_workload) {
                /* rtla asked to stop */
                params_u.should_run = 1;
@@ -1202,6 +1193,29 @@ int timerlat_hist_main(int argc, char *argv[])
                        err_msg("Error creating timerlat user-space threads\n");
        }
 
+       if (params->warmup > 0) {
+               debug_msg("Warming up for %d seconds\n", params->warmup);
+               sleep(params->warmup);
+               if (stop_tracing)
+                       goto out_hist;
+       }
+
+       /*
+        * Start the tracers here, after having set all instances.
+        *
+        * Let the trace instance start first for the case of hitting a stop
+        * tracing while enabling other instances. The trace instance is the
+        * one with most valuable information.
+        */
+       if (params->trace_output)
+               trace_instance_start(&record->trace);
+       if (!params->no_aa)
+               trace_instance_start(&aa->trace);
+       trace_instance_start(trace);
+
+       tool->start_time = time(NULL);
+       timerlat_hist_set_signals(params);
+
        while (!stop_tracing) {
                sleep(params->sleep_time);
 
@@ -1227,6 +1241,7 @@ int timerlat_hist_main(int argc, char *argv[])
                        }
                }
        }
+
        if (params->user_workload && !params_u.stopped_running) {
                params_u.should_run = 0;
                sleep(1);

diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
index bdcf8ef8f815ebd074699ffe5b1687e1b29e230e..410eb51749132b2ed1d303b9b512057cc6554bab 100644 (file)
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -45,6 +45,7 @@ struct timerlat_top_params {
        int                     user_top;
        int                     user_workload;
        int                     pretty_output;
+       int                     warmup;
        cpu_set_t               hk_cpu_set;
        struct sched_attr       sched_param;
        struct trace_events     *events;
@@ -444,7 +445,7 @@ 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]",
+               "         [-P priority] [--dma-latency us] [--aa-only us] [-C[=cgroup_name]] [-u] [--warm-up s]",
                "",
                "         -h/--help: print this menu",
                "         -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit",
@@ -475,6 +476,7 @@ static void timerlat_top_usage(char *usage)
                "                                                      in nanoseconds",
                "         -u/--user-threads: use rtla user-space threads instead of in-kernel timerlat threads",
                "         -U/--user-load: enable timerlat for user-defined user-space workload",
+               "            --warm-up s: let the workload run for s seconds before collecting data",
                NULL,
        };
 
@@ -541,13 +543,14 @@ static struct timerlat_top_params
                        {"no-aa",               no_argument,            0, '3'},
                        {"dump-tasks",          no_argument,            0, '4'},
                        {"aa-only",             required_argument,      0, '5'},
+                       {"warm-up",             required_argument,      0, '6'},
                        {0, 0, 0, 0}
                };
 
                /* getopt_long stores the option index here. */
                int option_index = 0;
 
-               c = getopt_long(argc, argv, "a:c:C::d:De:hH:i:np:P:qs:t::T:uU0:1:2:345:",
+               c = getopt_long(argc, argv, "a:c:C::d:De:hH:i:np:P:qs:t::T:uU0:1:2:345:6:",
                                 long_options, &option_index);
 
                /* detect the end of the options. */
@@ -704,6 +707,9 @@ static struct timerlat_top_params
                case '4':
                        params->dump_tasks = 1;
                        break;
+               case '6':
+                       params->warmup = get_llong_from_str(optarg);
+                       break;
                default:
                        timerlat_top_usage("Invalid option");
                }
@@ -971,22 +977,6 @@ int timerlat_top_main(int argc, char *argv[])
                }
        }
 
-       /*
-        * Start the tracers here, after having set all instances.
-        *
-        * Let the trace instance start first for the case of hitting a stop
-        * tracing while enabling other instances. The trace instance is the
-        * one with most valuable information.
-        */
-       if (params->trace_output)
-               trace_instance_start(&record->trace);
-       if (!params->no_aa && aa != top)
-               trace_instance_start(&aa->trace);
-       trace_instance_start(trace);
-
-       top->start_time = time(NULL);
-       timerlat_top_set_signals(params);
-
        if (params->user_workload) {
                /* rtla asked to stop */
                params_u.should_run = 1;
@@ -1006,6 +996,27 @@ int timerlat_top_main(int argc, char *argv[])
                        err_msg("Error creating timerlat user-space threads\n");
        }
 
+       if (params->warmup > 0) {
+               debug_msg("Warming up for %d seconds\n", params->warmup);
+               sleep(params->warmup);
+       }
+
+       /*
+        * Start the tracers here, after having set all instances.
+        *
+        * Let the trace instance start first for the case of hitting a stop
+        * tracing while enabling other instances. The trace instance is the
+        * one with most valuable information.
+        */
+       if (params->trace_output)
+               trace_instance_start(&record->trace);
+       if (!params->no_aa && aa != top)
+               trace_instance_start(&aa->trace);
+       trace_instance_start(trace);
+
+       top->start_time = time(NULL);
+       timerlat_top_set_signals(params);
+
        while (!stop_tracing) {
                sleep(params->sleep_time);