perf top tui: Wait till the first sample to refresh the screen.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 0b07cc3..417f757 100644 (file)
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -72,6 +72,7 @@ static struct perf_top top = {
        .target_tid             = -1,
        .active_symbols         = LIST_HEAD_INIT(top.active_symbols),
        .active_symbols_lock    = PTHREAD_MUTEX_INITIALIZER,
+       .active_symbols_cond    = PTHREAD_COND_INITIALIZER,
        .freq                   = 1000, /* 1 KHz */
 };
 
@@ -577,7 +578,17 @@ static void handle_keypress(struct perf_session *session, int c)
 
 static void *display_thread_tui(void *arg __used)
 {
-       perf_top__tui_browser(&top);
+       int err = 0;
+       pthread_mutex_lock(&top.active_symbols_lock);
+       while (list_empty(&top.active_symbols)) {
+               err = pthread_cond_wait(&top.active_symbols_cond,
+                                       &top.active_symbols_lock);
+               if (err)
+                       break;
+       }
+       pthread_mutex_unlock(&top.active_symbols_lock);
+       if (!err)
+               perf_top__tui_browser(&top);
        exit_browser(0);
        exit(0);
        return NULL;
@@ -776,8 +787,14 @@ static void perf_event__process_sample(const union perf_event *event,
                syme->count[evsel->idx]++;
                record_precise_ip(syme, evsel->idx, ip);
                pthread_mutex_lock(&top.active_symbols_lock);
-               if (list_empty(&syme->node) || !syme->node.next)
+               if (list_empty(&syme->node) || !syme->node.next) {
+                       static bool first = true;
                        __list_insert_active_sym(syme);
+                       if (first) {
+                               pthread_cond_broadcast(&top.active_symbols_cond);
+                               first = false;
+                       }
+               }
                pthread_mutex_unlock(&top.active_symbols_lock);
        }
 }

diff --git a/tools/perf/util/top.h b/tools/perf/util/top.h
index e8d28e2..96d1cb7 100644 (file)
--- a/tools/perf/util/top.h
+++ b/tools/perf/util/top.h
@@ -35,6 +35,7 @@ struct perf_top {
         */
        struct list_head   active_symbols;
        pthread_mutex_t    active_symbols_lock;
+       pthread_cond_t     active_symbols_cond;
        u64                samples;
        u64                kernel_samples, us_samples;
        u64                exact_samples;