perf hists browser: Warn about lost events

[sitara-epos/sitara-epos-kernel.git] / tools / perf / util / ui / browsers / hists.c

diff --git a/tools/perf/util/ui/browsers/hists.c b/tools/perf/util/ui/browsers/hists.c
index b8733c0770cd9e81050e4f8411b7f1d3dd72c3e6..d0c94b4596852d4f47ce266400ca3c7bb0013a96 100644 (file)
--- a/tools/perf/util/ui/browsers/hists.c
+++ b/tools/perf/util/ui/browsers/hists.c
@@ -295,6 +295,15 @@ static void hist_browser__set_folding(struct hist_browser *self, bool unfold)
        ui_browser__reset_index(&self->b);
 }
 
+static void ui_browser__warn_lost_events(struct ui_browser *browser)
+{
+       ui_browser__warning(browser, 4,
+               "Events are being lost, check IO/CPU overload!\n\n"
+               "You may want to run 'perf' using a RT scheduler policy:\n\n"
+               " perf top -r 80\n\n"
+               "Or reduce the sampling frequency.");
+}
+
 static int hist_browser__run(struct hist_browser *self, const char *ev_name,
                             void(*timer)(void *arg), void *arg, int delay_secs)
 {
@@ -318,8 +327,15 @@ static int hist_browser__run(struct hist_browser *self, const char *ev_name,
                case K_TIMER:
                        timer(arg);
                        ui_browser__update_nr_entries(&self->b, self->hists->nr_entries);
-                       hists__browser_title(self->hists, title, sizeof(title),
-                                            ev_name);
+
+                       if (self->hists->stats.nr_lost_warned !=
+                           self->hists->stats.nr_events[PERF_RECORD_LOST]) {
+                               self->hists->stats.nr_lost_warned =
+                                       self->hists->stats.nr_events[PERF_RECORD_LOST];
+                               ui_browser__warn_lost_events(&self->b);
+                       }
+
+                       hists__browser_title(self->hists, title, sizeof(title), ev_name);
                        ui_browser__show_title(&self->b, title);
                        continue;
                case 'D': { /* Debug */
@@ -883,7 +899,7 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
                        goto out_free_stack;
                case 'a':
                        if (!browser->has_symbols) {
-                               ui_browser__warning(&browser->b,
+                               ui_browser__warning(&browser->b, delay_secs * 2,
                        "Annotation is only available for symbolic views, "
                        "include \"sym\" in --sort to use it.");
                                continue;
@@ -1061,6 +1077,7 @@ out:
 struct perf_evsel_menu {
        struct ui_browser b;
        struct perf_evsel *selection;
+       bool lost_events, lost_events_warned;
 };
 
 static void perf_evsel_menu__write(struct ui_browser *browser,
@@ -1073,14 +1090,29 @@ static void perf_evsel_menu__write(struct ui_browser *browser,
        unsigned long nr_events = evsel->hists.stats.nr_events[PERF_RECORD_SAMPLE];
        const char *ev_name = event_name(evsel);
        char bf[256], unit;
+       const char *warn = " ";
+       size_t printed;
 
        ui_browser__set_color(browser, current_entry ? HE_COLORSET_SELECTED :
                                                       HE_COLORSET_NORMAL);
 
        nr_events = convert_unit(nr_events, &unit);
-       snprintf(bf, sizeof(bf), "%lu%c%s%s", nr_events,
-                unit, unit == ' ' ? "" : " ", ev_name);
-       slsmg_write_nstring(bf, browser->width);
+       printed = snprintf(bf, sizeof(bf), "%lu%c%s%s", nr_events,
+                          unit, unit == ' ' ? "" : " ", ev_name);
+       slsmg_printf("%s", bf);
+
+       nr_events = evsel->hists.stats.nr_events[PERF_RECORD_LOST];
+       if (nr_events != 0) {
+               menu->lost_events = true;
+               if (!current_entry)
+                       ui_browser__set_color(browser, HE_COLORSET_TOP);
+               nr_events = convert_unit(nr_events, &unit);
+               snprintf(bf, sizeof(bf), ": %ld%c%schunks LOST!", nr_events,
+                        unit, unit == ' ' ? "" : " ");
+               warn = bf;
+       }
+
+       slsmg_write_nstring(warn, browser->width - printed);
 
        if (current_entry)
                menu->selection = evsel;
@@ -1105,6 +1137,11 @@ static int perf_evsel_menu__run(struct perf_evsel_menu *menu,
                switch (key) {
                case K_TIMER:
                        timer(arg);
+
+                       if (!menu->lost_events_warned && menu->lost_events) {
+                               ui_browser__warn_lost_events(&menu->b);
+                               menu->lost_events_warned = true;
+                       }
                        continue;
                case K_RIGHT:
                case K_ENTER: