perf report: add more debugging

Add the offset of the file we are analyzing, and the size of the record.

In case of problems it's easier to see where the parser lost track.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Kacur <jkacur@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Documentation/perf_counter/builtin-report.c

@@ -645,7 +645,7 @@ static int __cmd_report(void)
 	char *buf;
 	event_t *event;
 	int ret, rc = EXIT_FAILURE;
-	unsigned long total = 0, total_mmap = 0, total_comm = 0, total_unknown;
+	unsigned long total = 0, total_mmap = 0, total_comm = 0, total_unknown = 0;
 
 	input = open(input_name, O_RDONLY);
 	if (input < 0) {
@@ -699,8 +699,6 @@ static int __cmd_report(void)
 		goto done;
 	}
 
-	head += event->header.size;
-
 	if (event->header.misc & PERF_EVENT_MISC_OVERFLOW) {
 		char level;
 		int show = 0;
@@ -709,7 +707,9 @@ static int __cmd_report(void)
 		uint64_t ip = event->ip.ip;
 
 		if (dump_trace) {
-			fprintf(stderr, "PERF_EVENT (IP, %d): %d: %p\n",
+			fprintf(stderr, "%p [%p]: PERF_EVENT (IP, %d): %d: %p\n",
+				(void *)(offset + head),
+				(void *)(long)(event->header.size),
 				event->header.misc,
 				event->ip.pid,
 				(void *)event->ip.ip);
@@ -753,7 +753,9 @@ static int __cmd_report(void)
 		struct map *map = map__new(&event->mmap);
 
 		if (dump_trace) {
-			fprintf(stderr, "PERF_EVENT_MMAP: [%p(%p) @ %p]: %s\n",
+			fprintf(stderr, "%p [%p]: PERF_EVENT_MMAP: [%p(%p) @ %p]: %s\n",
+				(void *)(offset + head),
+				(void *)(long)(event->header.size),
 				(void *)event->mmap.start,
 				(void *)event->mmap.len,
 				(void *)event->mmap.pgoff,
@@ -771,7 +773,9 @@ static int __cmd_report(void)
 		struct thread *thread = threads__findnew(event->comm.pid);
 
 		if (dump_trace) {
-			fprintf(stderr, "PERF_EVENT_COMM: %s:%d\n",
+			fprintf(stderr, "%p [%p]: PERF_EVENT_COMM: %s:%d\n",
+				(void *)(offset + head),
+				(void *)(long)(event->header.size),
 				event->comm.comm, event->comm.pid);
 		}
 		if (thread == NULL ||
@@ -783,12 +787,16 @@ static int __cmd_report(void)
 		break;
 	}
 	default: {
-		fprintf(stderr, "skipping unknown header type: %d\n",
+		fprintf(stderr, "%p [%p]: skipping unknown header type: %d\n",
+			(void *)(offset + head),
+			(void *)(long)(event->header.size),
 			event->header.type);
 		total_unknown++;
 	}
 	}
 
+	head += event->header.size;
+
 	if (offset + head < stat.st_size)
 		goto more;