Add spark counter tracing

A new eventlog event containing 7 spark counters/statistics: sparks
created, dud, overflowed, converted, GC'd, fizzled and remaining.
These are maintained and logged separately for each capability.
We log them at startup, on each GC (minor and major) and on shutdown.

2 files changed, 37 insertions, 1 deletions

diff --git a/rts/eventlog/EventLog.c b/rts/eventlog/EventLog.c
index cea313e660..1e63a94c88 100644
--- a/rts/eventlog/EventLog.c
+++ b/rts/eventlog/EventLog.c
@@ -84,7 +84,8 @@ char *EventDesc[] = {
   [EVENT_PROGRAM_ARGS]        = "Program arguments",
   [EVENT_PROGRAM_ENV]         = "Program environment variables",
   [EVENT_OSPROCESS_PID]       = "Process ID",
-  [EVENT_OSPROCESS_PPID]      = "Parent process ID"
+  [EVENT_OSPROCESS_PPID]      = "Parent process ID",
+  [EVENT_SPARK_COUNTERS]      = "Spark counters"
 };
 
 // Event type. 
@@ -314,6 +315,10 @@ initEventLogging(void)
             eventTypes[t].size = 0xffff;
             break;
 
+        case EVENT_SPARK_COUNTERS:   // (cap, 7*counter)
+            eventTypes[t].size = 7 * sizeof(StgWord64);
+            break;
+
         case EVENT_BLOCK_MARKER:
             eventTypes[t].size = sizeof(StgWord32) + sizeof(EventTimestamp) + 
                 sizeof(EventCapNo);
@@ -478,6 +483,30 @@ postSchedEvent (Capability *cap,
     }
 }
 
+void
+postSparkCountersEvent (Capability *cap, 
+                        SparkCounters counters,
+                        StgWord remaining)
+{
+    EventsBuf *eb;
+
+    eb = &capEventBuf[cap->no];
+
+    if (!hasRoomForEvent(eb, EVENT_SPARK_COUNTERS)) {
+        // Flush event buffer to make room for new event.
+        printAndClearEventBuf(eb);
+    }
+    
+    postEventHeader(eb, EVENT_SPARK_COUNTERS);
+    postWord64(eb,counters.created);
+    postWord64(eb,counters.dud);
+    postWord64(eb,counters.overflowed);
+    postWord64(eb,counters.converted);
+    postWord64(eb,counters.gcd);
+    postWord64(eb,counters.fizzled);
+    postWord64(eb,remaining);
+}
+
 void postCapsetModifyEvent (EventTypeNum tag,
                             EventCapsetID capset,
                             StgWord32 other)
diff --git a/rts/eventlog/EventLog.h b/rts/eventlog/EventLog.h
index 602ac2c87b..431292732f 100644
--- a/rts/eventlog/EventLog.h
+++ b/rts/eventlog/EventLog.h
@@ -69,6 +69,13 @@ void postCapsetVecEvent (EventTypeNum tag,
                          int argc,
                          char *msg[]);
 
+/*
+ * Post an event with several counters relating to `par` sparks.
+ */
+void postSparkCountersEvent (Capability *cap, 
+                             SparkCounters counters,
+                             StgWord remaining);
+
 #else /* !TRACING */
 
 INLINE_HEADER void postSchedEvent (Capability *cap  STG_UNUSED,