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

Support limiting deepest idle state also for timerlat-hist.

Link: https://lore.kernel.org/20241017140914.3200454-6-tglozar@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index d49c8f0855fe057701e71de02493033011fef65e..01dd337da13ac8f0441055c201fd748462a21adf 100644 (file)
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -55,6 +55,7 @@ struct timerlat_hist_params {
        int                     entries;
        int                     warmup;
        int                     buffer_size;
+       int                     deepest_idle_state;
 };
 
 struct timerlat_hist_cpu {
@@ -655,7 +656,7 @@ 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|-k]",
-               "         [--warm-up s]",
+               "         [--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",
@@ -695,6 +696,7 @@ static void timerlat_hist_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,
        };
 
@@ -732,6 +734,9 @@ static struct timerlat_hist_params
        /* disabled by default */
        params->dma_latency = -1;
 
+       /* disabled by default */
+       params->deepest_idle_state = -2;
+
        /* display data in microseconds */
        params->output_divisor = 1000;
        params->bucket_size = 1;
@@ -772,6 +777,7 @@ static struct timerlat_hist_params
                        {"dump-task",           no_argument,            0, '\1'},
                        {"warm-up",             required_argument,      0, '\2'},
                        {"trace-buffer-size",   required_argument,      0, '\3'},
+                       {"deepest-idle-state",  required_argument,      0, '\4'},
                        {0, 0, 0, 0}
                };
 
@@ -960,6 +966,9 @@ static struct timerlat_hist_params
                case '\3':
                        params->buffer_size = get_llong_from_str(optarg);
                        break;
+               case '\4':
+                       params->deepest_idle_state = get_llong_from_str(optarg);
+                       break;
                default:
                        timerlat_hist_usage("Invalid option");
                }
@@ -1152,6 +1161,7 @@ int timerlat_hist_main(int argc, char *argv[])
        int return_value = 1;
        pthread_t timerlat_u;
        int retval;
+       int nr_cpus, i;
 
        params = timerlat_hist_parse_args(argc, argv);
        if (!params)
@@ -1201,6 +1211,28 @@ int timerlat_hist_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) {
@@ -1332,6 +1364,13 @@ out_hist:
        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:
@@ -1340,6 +1379,7 @@ out_free:
        osnoise_destroy_tool(record);
        osnoise_destroy_tool(tool);
        free(params);
+       free_cpu_idle_disable_states();
 out_exit:
        exit(return_value);
 }