perf top: Improve lost events warning

Now it warns everytime that new events are lost.

And the TUI also warns now.

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-w1n168yrvrppnq6887s4u0wx@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/tools/perf/util/ui/browsers/top.c b/tools/perf/util/ui/browsers/top.c
index 9d938106510f..9b6b43b32ac8 100644
--- a/tools/perf/util/ui/browsers/top.c
+++ b/tools/perf/util/ui/browsers/top.c
@@ -11,10 +11,12 @@
 #include "../helpline.h"
 #include "../libslang.h"
 #include "../util.h"
+#include "../ui.h"
 #include "../../evlist.h"
 #include "../../hist.h"
 #include "../../sort.h"
 #include "../../symbol.h"
+#include "../../session.h"
 #include "../../top.h"
 
 struct perf_top_browser {
@@ -143,6 +145,25 @@ do_annotation:
         symbol__tui_annotate(sym, syme->map, 0, top->delay_secs * 1000);
 }
 
+static void perf_top_browser__warn_lost(struct perf_top_browser *browser)
+{
+        struct perf_top *top = browser->b.priv;
+        char msg[128];
+        int len;
+
+        top->total_lost_warned = top->session->hists.stats.total_lost;
+        pthread_mutex_lock(&ui__lock);
+        ui_browser__set_color(&browser->b, HE_COLORSET_TOP);
+        len = snprintf(msg, sizeof(msg),
+                      " WARNING: LOST %" PRIu64 " events, Check IO/CPU overload",
+                      top->total_lost_warned);
+        if (len > browser->b.width)
+                len = browser->b.width;
+        SLsmg_gotorc(0, browser->b.width - len);
+        slsmg_write_nstring(msg, len);
+        pthread_mutex_unlock(&ui__lock);
+}
+
 static int perf_top_browser__run(struct perf_top_browser *browser)
 {
         int key;
@@ -174,6 +195,9 @@ static int perf_top_browser__run(struct perf_top_browser *browser)
                         ui_browser__set_color(&browser->b, NEWT_COLORSET_ROOT);
                         SLsmg_gotorc(0, 0);
                         slsmg_write_nstring(title, browser->b.width);
+
+                        if (top->total_lost_warned != top->session->hists.stats.total_lost)
+                                perf_top_browser__warn_lost(browser);
                         break;
                 case 'a':
                 case NEWT_KEY_RIGHT: