[tip:perf/core] perf report: Improve error msg when no first/last sample time found

[tip-bot for Jin Yao]

Commit-ID:  eb0b419eff8cf51af8e16cc8c5d2a92d19824266
Gitweb:     https://git.kernel.org/tip/eb0b419eff8cf51af8e16cc8c5d2a92d19824266
Author:     Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
AuthorDate: Wed, 10 Jan 2018 23:00:26 +0800
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 17 Jan 2018 10:23:34 -0300

perf report: Improve error msg when no first/last sample time found

The following message will be returned to user when executing
'perf report --time' if perf data file doesn't contain the
first/last sample time.

"HINT: no first/last sample time found in perf data.
 Please use latest perf binary to execute 'perf record'
 (if '--buildid-all' is enabled, needs to set '--timestamp-boundary')."

Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
Reviewed-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1515596433-24653-2-git-send-email-yao.jin@xxxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/builtin-report.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 6593779..7d4f0a5 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -1300,7 +1300,9 @@ repeat:
 	if (perf_time__parse_str(report.ptime_range, report.time_str) != 0) {
 		if (session->evlist->first_sample_time == 0 &&
 		    session->evlist->last_sample_time == 0) {
-			pr_err("No first/last sample time in perf data\n");
+			pr_err("HINT: no first/last sample time found in perf data.\n"
+			       "Please use latest perf binary to execute 'perf record'\n"
+			       "(if '--buildid-all' is enabled, please set '--timestamp-boundary').\n");
 			return -EINVAL;
 		}