[tip:perf/core] perf report: Show error message when processing sample fails

[tip-bot for Namhyung Kim <tipbot@zytor.com>]

Commit-ID:  25b1606be1a910a63a23c3d1006581c9aad4e6e3
Gitweb:     http://git.kernel.org/tip/25b1606be1a910a63a23c3d1006581c9aad4e6e3
Author:     Namhyung Kim <namhyung@kernel.org>
AuthorDate: Sat, 28 Nov 2015 02:32:37 +0900
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Fri, 27 Nov 2015 16:56:32 -0300

perf report: Show error message when processing sample fails

Currently when perf fails to process samples for some reason, it doesn't
show any message about the failure.  This is very inconvenient for users
especially on TUI as screen is reset after the failure.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1448645559-31167-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-report.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 8a9c690..af5db88 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -513,20 +513,26 @@ static int __cmd_report(struct report *rep)
 	if (rep->cpu_list) {
 		ret = perf_session__cpu_bitmap(session, rep->cpu_list,
 					       rep->cpu_bitmap);
-		if (ret)
+		if (ret) {
+			ui__error("failed to set cpu bitmap\n");
 			return ret;
+		}
 	}
 
 	if (rep->show_threads)
 		perf_read_values_init(&rep->show_threads_values);
 
 	ret = report__setup_sample_type(rep);
-	if (ret)
+	if (ret) {
+		/* report__setup_sample_type() already showed error message */
 		return ret;
+	}
 
 	ret = perf_session__process_events(session);
-	if (ret)
+	if (ret) {
+		ui__error("failed to process sample\n");
 		return ret;
+	}
 
 	report__warn_kptr_restrict(rep);