perf top: Move the timeout warning from event processing thread to display thread

index f3aa9d0..1e77515 100644
@@ -2371,7 +2371,7 @@ static int perf_c2c__browse_cacheline(struct hist_entry *he)
 	c2c_browser__update_nr_entries(browser);
 
 	while (1) {
-		key = hist_browser__run(browser, "? - help", true);
+		key = hist_browser__run(browser, "? - help", true, NULL);
 
 		switch (key) {
 		case 's':

@@ -2440,7 +2440,7 @@ static int perf_c2c__hists_browse(struct hists *hists)
 	c2c_browser__update_nr_entries(browser);
 
 	while (1) {
-		key = hist_browser__run(browser, "? - help", true);
+		key = hist_browser__run(browser, "? - help", true, NULL);
 
 		switch (key) {
 		case 'q':

index 257c9c1..2fc1273 100644
@@ -561,7 +561,8 @@ static int report__browse_hists(struct report *rep)
 		ret = perf_evlist__tui_browse_hists(evlist, help, NULL,
 						    rep->min_percent,
 						    &session->header.env,
-						    true, &rep->annotation_opts);
+						    true, &rep->annotation_opts,
+						    NULL);
 		/*
 		 * Usually "ret" is the last pressed key, and we only
 		 * care if the key notifies us to switch data file.

index d21d875..95409de 100644
@@ -584,6 +584,8 @@ static void *display_thread_tui(void *arg)
 		.refresh	= top->delay_secs,
 	};
 
+	sleep(top->delay_secs);
+
 	/* In order to read symbols from other namespaces perf to  needs to call
 	 * setns(2).  This isn't permitted if the struct_fs has multiple users.
 	 * unshare(2) the fs so that we may continue to setns into namespaces

@@ -607,7 +609,8 @@ static void *display_thread_tui(void *arg)
 				      top->min_percent,
 				      &top->session->header.env,
 				      !top->record_opts.overwrite,
-				      &top->annotation_opts);
+				      &top->annotation_opts,
+				      &top->nr_rb_read);
 
 	done = 1;
 	return NULL;

@@ -633,6 +636,11 @@ static void *display_thread(void *arg)
 	struct termios save;
 	struct perf_top *top = arg;
 	int delay_msecs, c;
+	bool rb_read_timeout_warned = false;
+	bool rb_read_timeout = false;
+	int last_nr_rb_read = 0;
+
+	sleep(top->delay_secs);
 
 	/* In order to read symbols from other namespaces perf to  needs to call
 	 * setns(2).  This isn't permitted if the struct_fs has multiple users.

@@ -651,12 +659,26 @@ static void *display_thread(void *arg)
 
 	while (!done) {
 		perf_top__print_sym_table(top);
+
+		if (!rb_read_timeout_warned && rb_read_timeout) {
+			color_fprintf(stdout, PERF_COLOR_RED,
+				      "Too slow to read ring buffer.\n"
+				      "Please try increasing the period (-c) or\n"
+				      "decreasing the freq (-F) or\n"
+				      "limiting the number of CPUs (-C)\n");
+			rb_read_timeout_warned = true;
+		}
 		/*
 		 * Either timeout expired or we got an EINTR due to SIGWINCH,
 		 * refresh screen in both cases.
 		 */
 		switch (poll(&stdin_poll, 1, delay_msecs)) {
 		case 0:
+			if (atomic_read(&top->nr_rb_read) == last_nr_rb_read)
+				rb_read_timeout = true;
+			else
+				rb_read_timeout = false;
+			last_nr_rb_read = atomic_read(&top->nr_rb_read);
 			continue;
 		case -1:
 			if (errno == EINTR)

@@ -881,10 +903,10 @@ static void perf_top__mmap_read(struct perf_top *top)
 {
 	bool overwrite = top->record_opts.overwrite;
 	struct perf_evlist *evlist = top->evlist;
-	unsigned long long start, end;
 	int i;
 
-	start = rdclock();
+	atomic_inc(&top->nr_rb_read);
+
 	if (overwrite)
 		perf_evlist__toggle_bkw_mmap(evlist, BKW_MMAP_DATA_PENDING);
 

@@ -895,13 +917,6 @@ static void perf_top__mmap_read(struct perf_top *top)
 		perf_evlist__toggle_bkw_mmap(evlist, BKW_MMAP_EMPTY);
 		perf_evlist__toggle_bkw_mmap(evlist, BKW_MMAP_RUNNING);
 	}
-	end = rdclock();
-
-	if ((end - start) > (unsigned long long)top->delay_secs * NSEC_PER_SEC)
-		ui__warning("Too slow to read ring buffer.\n"
-			    "Please try increasing the period (-c) or\n"
-			    "decreasing the freq (-F) or\n"
-			    "limiting the number of CPUs (-C)\n");
 }
 
 /*

@@ -1137,8 +1152,6 @@ static int __cmd_top(struct perf_top *top)
 	/* Wait for a minimal set of events before starting the snapshot */
 	perf_evlist__poll(top->evlist, 100);
 
-	perf_top__mmap_read(top);
-
 	ret = -1;
 	if (pthread_create(&thread, NULL, (use_browser > 0 ? display_thread_tui :
 							    display_thread), top)) {

@@ -1146,6 +1159,8 @@ static int __cmd_top(struct perf_top *top)
 		goto out_delete;
 	}
 
+	perf_top__mmap_read(top);
+
 	if (top->realtime_prio) {
 		struct sched_param param;
 

145 lines not on this page · raw message

index 91d3e18..af6c1b9 100644
@@ -32,7 +32,7 @@ struct hist_browser {
 struct hist_browser *hist_browser__new(struct hists *hists);
 void hist_browser__delete(struct hist_browser *browser);
 int hist_browser__run(struct hist_browser *browser, const char *help,
-		      bool warn_lost_event);
+		      bool warn_lost_event, atomic_t *nr_rb_read);
 void hist_browser__init(struct hist_browser *browser,
 			struct hists *hists);
 #endif /* _PERF_UI_BROWSER_HISTS_H_ */

index 3badd7f..67f31163 100644
@@ -442,7 +442,8 @@ int perf_evlist__tui_browse_hists(struct perf_evlist *evlist, const char *help,
 				  float min_pcnt,
 				  struct perf_env *env,
 				  bool warn_lost_event,
-				  struct annotation_options *annotation_options);
+				  struct annotation_options *annotation_options,
+				  atomic_t *nr_rb_read);
 int script_browse(const char *script_opt);
 #else
 static inline

@@ -452,7 +453,8 @@ int perf_evlist__tui_browse_hists(struct perf_evlist *evlist __maybe_unused,
 				  float min_pcnt __maybe_unused,
 				  struct perf_env *env __maybe_unused,
 				  bool warn_lost_event __maybe_unused,
-				  struct annotation_options *annotation_options __maybe_unused)
+				  struct annotation_options *annotation_options __maybe_unused,
+				  atomic_t *nr_rb_read __maybe_unused)
 {
 	return 0;
 }

index 9add1f7..2869d9d 100644
@@ -40,6 +40,7 @@ struct perf_top {
 	const char	   *sym_filter;
 	float		   min_percent;
 	unsigned int	   nr_threads_synthesize;
+	atomic_t	   nr_rb_read;
 };
 
 #define CONSOLE_CLEAR ""