perf ui/tui: Show fatal error message only if exists

When perf exits with some error it shows the error message with ui__error() or ui__warning() and then calls ui__exit() during exit_browser().

On TUI, it then shows a window titled "Fatal Error" to inform user a last message which might be related with this condition. However it sometimes contains no message and just annoyes users.

The usual case for this is running perf top as normal user. (And /proc/sys/kernel/perf_event_paranoid being 1).

Signed-off-by Namhyung Kim <[email protected]>

---
 tools/perf/ui/tui/helpline.c | 3 +++
 tools/perf/ui/tui/setup.c    | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

tools/perf/ui/tui/helpline.c +3 -0

index 1c8b9afd5d6e..88f5143a5981 100644
@@ -9,6 +9,7 @@
 #include "../libslang.h"
 
 char ui_helpline__last_msg[1024];
+bool tui_helpline__set;
 
 static void tui_helpline__pop(void)
 {

@@ -35,6 +36,8 @@ static int tui_helpline__show(const char *format, va_list ap)
 			sizeof(ui_helpline__last_msg) - backlog, format, ap);
 	backlog += ret;
 
+	tui_helpline__set = true;
+
 	if (ui_helpline__last_msg[backlog - 1] == '\n') {
 		ui_helpline__puts(ui_helpline__last_msg);
 		SLsmg_refresh();

tools/perf/ui/tui/setup.c +1 -0

index 3c38f25b1695..b77e1d771363 100644
@@ -17,6 +17,7 @@
 static volatile int ui__need_resize;
 
 extern struct perf_error_ops perf_tui_eops;
+extern bool tui_helpline__set;
 
 extern void hist_browser__init_hpp(void);
 

Quoted 10 lines · Namhyung Kim

When perf exits with some error it shows the error message with ui__error() or ui__warning() and then calls ui__exit() during exit_browser().

On TUI, it then shows a window titled "Fatal Error" to inform user a last message which might be related with this condition. However it sometimes contains no message and just annoyes users.

The usual case for this is running perf top as normal user. (And /proc/sys/kernel/perf_event_paranoid being 1).

cool, I couldn't recreate the 'no message' box but I recall seeing it

Quoted 42 lines

Signed-off-by Namhyung Kim <[email protected]>

---
 tools/perf/ui/tui/helpline.c | 3 +++
 tools/perf/ui/tui/setup.c    | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

tools/perf/ui/tui/helpline.c +3 -0

index 1c8b9afd5d6e..88f5143a5981 100644
@@ -9,6 +9,7 @@
 #include "../libslang.h"
 
 char ui_helpline__last_msg[1024];
+bool tui_helpline__set;
 
 static void tui_helpline__pop(void)
 {

@@ -35,6 +36,8 @@ static int tui_helpline__show(const char *format, va_list ap)
 			sizeof(ui_helpline__last_msg) - backlog, format, ap);
 	backlog += ret;
 
+	tui_helpline__set = true;
+
 	if (ui_helpline__last_msg[backlog - 1] == '\n') {
 		ui_helpline__puts(ui_helpline__last_msg);
 		SLsmg_refresh();

tools/perf/ui/tui/setup.c +1 -0

index 3c38f25b1695..b77e1d771363 100644
@@ -17,6 +17,7 @@
 static volatile int ui__need_resize;
 
 extern struct perf_error_ops perf_tui_eops;
+extern bool tui_helpline__set;
 
 extern void hist_browser__init_hpp(void);
 

@@ -159,7 +160,7 @@ int ui__init(void)
 

tools/perf/ui/tui/setup.c int ui__init(void) · line 166

Quoted 7 lines

tools/perf/ui/tui/setup.c +1 -1

 void ui__exit(bool wait_for_ok)
 {
-	if (wait_for_ok)
+	if (wait_for_ok && tui_helpline__set)
 		ui__question_window("Fatal Error",
 				    ui_helpline__last_msg,
 				    "Press any key...", 0);

looks like we display ui_helpline__last_msg also in ui/browsers/annotate.c

do we want to have some common function that unsets tui_helpline__set so we're sure we dont get the message twice?

Quoted 3 lines

Quoted 1 line

"Press any key...", 0);

looks like we display ui_helpline__last_msg also in ui/browsers/annotate.c

Right, I also saw it.

Quoted 1 line

Quoted 2 lines

do we want to have some common function that unsets tui_helpline__set so we're sure we dont get the message twice?

I doubt that it's really needed.. The annotation code does not propagate an error so the wait_for_ok arg in ui__exit() will be always false. In addition, I think it's better to use ui__error() or ui__warning() directly at the point when something bad happened and we need to inform user.