[PATCH 1/3] perf top: Use active evsel for non-sample events on old kernel

[Namhyung Kim]

If multiple events are specified on old kernel,
perf_evlist__id2evsel() returns NULL for non-sampling events
since the sample.id doesn't contain valid value, and it triggers
assert below. If only one event is given, the function returns
the evsel regardless of sample.id, this is why most case cause
no problem on old kernel.

Fix it by using active evsel.

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxx>
---
 tools/perf/builtin-top.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index d89dec90103e..2c9fa1e48854 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -762,6 +762,14 @@ static void perf_top__mmap_read_idx(struct perf_top *top, int idx)
 		}
 
 		evsel = perf_evlist__id2evsel(session->evlist, sample.id);
+		if (evsel == NULL && !session->sample_id_all &&
+		    event->header.type != PERF_RECORD_SAMPLE) {
+			/*
+			 * Old kernel, no sample_id_all field.
+			 * Just use active evsel.
+			 */
+			evsel = top->sym_evsel;
+		}
 		assert(evsel != NULL);
 
 		origin = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
-- 
1.7.8.2

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