[PATCH 4/5] rtla/timerlat: Add --disable-idle-states for hist

[tglozar]

From: Tomas Glozar <tglo...@redhat.com>

Support disabling idle states also for timerlat-hist.

Signed-off-by: Tomas Glozar <tglo...@redhat.com>
---
 tools/tracing/rtla/src/timerlat_hist.c | 35 +++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/tools/tracing/rtla/src/timerlat_hist.c 
b/tools/tracing/rtla/src/timerlat_hist.c
index a3907c390d67..69d427841d14 100644
--- 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                     disable_idle_states;
 };
 
 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] [--disable-idle-states]",
                "",
                "         -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",
+               "            --disable-idle-states: disable all idle states for 
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->disable_idle_states = 0;
+
        /* 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'},
+                       {"disable-idle-states", no_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->disable_idle_states = 1;
+                       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 i;
 
        params = timerlat_hist_parse_args(argc, argv);
        if (!params)
@@ -1201,6 +1211,21 @@ int timerlat_hist_main(int argc, char *argv[])
                }
        }
 
+       if (params->disable_idle_states) {
+               for (i = 0; i < sysconf(_SC_NPROCESSORS_CONF); 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_cpu_idle_disable_state(i, 1) < 0) {
+                               err_msg("Could not disable cpu idle state.\n");
+                               goto out_free;
+                       }
+               }
+       }
+
        if (params->trace_output) {
                record = osnoise_init_trace_tool("timerlat");
                if (!record) {
@@ -1332,6 +1357,13 @@ int timerlat_hist_main(int argc, char *argv[])
        timerlat_aa_destroy();
        if (dma_latency_fd >= 0)
                close(dma_latency_fd);
+       if (params->disable_idle_states) {
+               for (i = 0; i < sysconf(_SC_NPROCESSORS_CONF); 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 +1372,7 @@ int timerlat_hist_main(int argc, char *argv[])
        osnoise_destroy_tool(record);
        osnoise_destroy_tool(tool);
        free(params);
+       free_cpu_idle_disable_states();
 out_exit:
        exit(return_value);
 }
-- 
2.43.0