[PATCH 2/2] perf report: Support switching data w/ and w/o callchains

[Namhyung Kim <namhyung@kernel.org>]

The symbol_conf.use_callchain should be reset when switching to new data
file, otherwise report__setup_sample_type() will show an error message
that it enabled callchains but no callchain data.  The function also
will turn on the callchains if the data has PERF_SAMPLE_CALLCHAIN so I
think it's ok to reset symbol_conf.use_callchain here.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-report.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index c99b14a852dbdfbb..e7a7e9df1b42b3a7 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -1826,6 +1826,11 @@ int cmd_report(int argc, const char **argv)
 	if (ret == K_SWITCH_INPUT_DATA || ret == K_RELOAD) {
 		perf_session__delete(session);
 		last_key = K_SWITCH_INPUT_DATA;
+		/*
+		 * To support switching between data with and without callchains.
+		 * report__setup_sample_type() will update it properly.
+		 */
+		symbol_conf.use_callchain = false;
 		goto repeat;
 	} else
 		ret = 0;
-- 
2.48.1.502.g6dc24dfdaf-goog