perf timechart: Fix the wakeup-arrows that point to non-visible processes

The timechart wakeup arrows currently show no process
information when the waker/wakee are processes that are not
actually chosen to be shown on the timechart.

This patch fixes this oversight, by looking through all
processes (after giving preference to visible processes) as well
as falling back to just showing the PID if no name for the
process can be resolved.

Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>

1 files changed, 26 insertions, 2 deletions

diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index 702d8fe58fbc..e8a510d935e5 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -765,19 +765,40 @@ static void draw_wakeups(void)
 					if (c->Y && c->start_time <= we->time && c->end_time >= we->time) {
 						if (p->pid == we->waker) {
 							from = c->Y;
-							task_from = c->comm;
+							task_from = strdup(c->comm);
 						}
 						if (p->pid == we->wakee) {
 							to = c->Y;
-							task_to = c->comm;
+							task_to = strdup(c->comm);
 						}
 					}
 					c = c->next;
 				}
+				c = p->all;
+				while (c) {
+					if (p->pid == we->waker && !from) {
+						from = c->Y;
+						task_from = strdup(c->comm);
+					}
+					if (p->pid == we->wakee && !to) {
+						to = c->Y;
+						task_to = strdup(c->comm);
+					}
+					c = c->next;
+				}
 			}
 			p = p->next;
 		}
 
+		if (!task_from) {
+			task_from = malloc(40);
+			sprintf(task_from, "[%i]", we->waker);
+		}
+		if (!task_to) {
+			task_to = malloc(40);
+			sprintf(task_to, "[%i]", we->wakee);
+		}
+
 		if (we->waker == -1)
 			svg_interrupt(we->time, to);
 		else if (from && to && abs(from - to) == 1)
@@ -785,6 +806,9 @@ static void draw_wakeups(void)
 		else
 			svg_partial_wakeline(we->time, from, task_from, to, task_to);
 		we = we->next;
+
+		free(task_from);
+		free(task_to);
 	}
 }