perf hists browser: Warn about lost events
Just like the old perf top --tui and the --stdio version.
But because we have the initial menu to choose which event to show in a
session with multiple events we can see how many chunks were lost in
each of the event types, clarifying which events are being affected the
most.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-47yyqbubmjzch2chezmb21m6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/ui/browser.c b/tools/perf/util/ui/browser.c
index d2051be..5568291 100644
--- a/tools/perf/util/ui/browser.c
+++ b/tools/perf/util/ui/browser.c
@@ -176,16 +176,29 @@
ui_browser__refresh(browser);
}
-int ui_browser__warning(struct ui_browser *browser, const char *format, ...)
+int ui_browser__warning(struct ui_browser *browser, int timeout,
+ const char *format, ...)
{
va_list args;
- int key;
+ char *text;
+ int key = 0, err;
va_start(args, format);
- while ((key = __ui__warning("Warning!", format, args)) == K_RESIZE)
- ui_browser__handle_resize(browser);
+ err = vasprintf(&text, format, args);
va_end(args);
+ if (err < 0) {
+ va_start(args, format);
+ ui_helpline__vpush(format, args);
+ va_end(args);
+ } else {
+ while ((key == ui__question_window("Warning!", text,
+ "Press any key...",
+ timeout)) == K_RESIZE)
+ ui_browser__handle_resize(browser);
+ free(text);
+ }
+
return key;
}
diff --git a/tools/perf/util/ui/browser.h b/tools/perf/util/ui/browser.h
index fb1c598..84d761b 100644
--- a/tools/perf/util/ui/browser.h
+++ b/tools/perf/util/ui/browser.h
@@ -45,7 +45,8 @@
void ui_browser__update_nr_entries(struct ui_browser *browser, u32 nr_entries);
void ui_browser__handle_resize(struct ui_browser *browser);
-int ui_browser__warning(struct ui_browser *browser, const char *format, ...);
+int ui_browser__warning(struct ui_browser *browser, int timeout,
+ const char *format, ...);
int ui_browser__help_window(struct ui_browser *browser, const char *text);
bool ui_browser__dialog_yesno(struct ui_browser *browser, const char *text);
diff --git a/tools/perf/util/ui/browsers/hists.c b/tools/perf/util/ui/browsers/hists.c
index b8733c0..d0c94b4 100644
--- a/tools/perf/util/ui/browsers/hists.c
+++ b/tools/perf/util/ui/browsers/hists.c
@@ -295,6 +295,15 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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: