perf evsel: Add option to limit stack depth in callchain dumps

Option is used by upcoming timehist command.

Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1375930261-77273-12-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-script.c

@@ -402,7 +402,8 @@ static void print_sample_bts(union perf_event *event,
 		else
 			printf("\n");
 		perf_evsel__print_ip(evsel, event, sample, machine,
-				     output[attr->type].print_ip_opts);
+				     output[attr->type].print_ip_opts,
+				     PERF_MAX_STACK_DEPTH);
 	}
 
 	printf(" => ");
@@ -444,7 +445,8 @@ static void process_event(union perf_event *event, struct perf_sample *sample,
 			printf("\n");
 
 		perf_evsel__print_ip(evsel, event, sample, machine,
-				     output[attr->type].print_ip_opts);
+				     output[attr->type].print_ip_opts,
+				     PERF_MAX_STACK_DEPTH);
 	}
 
 	printf("\n");

tools/perf/util/session.c

@@ -1489,7 +1489,7 @@ struct perf_evsel *perf_session__find_first_evtype(struct perf_session *session,
 
 void perf_evsel__print_ip(struct perf_evsel *evsel, union perf_event *event,
 			  struct perf_sample *sample, struct machine *machine,
-			  unsigned int print_opts)
+			  unsigned int print_opts, unsigned int stack_depth)
 {
 	struct addr_location al;
 	struct callchain_cursor_node *node;
@@ -1517,7 +1517,7 @@ void perf_evsel__print_ip(struct perf_evsel *evsel, union perf_event *event,
 		}
 		callchain_cursor_commit(&callchain_cursor);
 
-		while (1) {
+		while (stack_depth) {
 			node = callchain_cursor_current(&callchain_cursor);
 			if (!node)
 				break;
@@ -1544,6 +1544,8 @@ void perf_evsel__print_ip(struct perf_evsel *evsel, union perf_event *event,
 				printf("\n");
 
 			callchain_cursor_advance(&callchain_cursor);
+
+			stack_depth--;
 		}
 
 	} else {

tools/perf/util/session.h

@@ -109,7 +109,7 @@ struct perf_evsel *perf_session__find_first_evtype(struct perf_session *session,
 
 void perf_evsel__print_ip(struct perf_evsel *evsel, union perf_event *event,
 			  struct perf_sample *sample, struct machine *machine,
-			  unsigned int print_opts);
+			  unsigned int print_opts, unsigned int stack_depth);
 
 int perf_session__cpu_bitmap(struct perf_session *session,
 			     const char *cpu_list, unsigned long *cpu_bitmap);