perf cs-etm: Generate branch sample for CS_ETM_TRACE_ON packet

CS_ETM_TRACE_ON packet itself can give the info that there have a
discontinuity in the trace, this patch is to add branch sample for
CS_ETM_TRACE_ON packet if it is inserted in the middle of CS_ETM_RANGE
packets; as result we can have hint for the trace discontinuity.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kim Phillips <kim.phillips@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Walker <robert.walker@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1531295145-596-7-git-send-email-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index d3b794286bcaa3f05cf165aef992e10d3a7f8e35..2ae640257fdbbe897d8c398d1dfeeb406d1c9fb1 100644 (file)
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -910,13 +910,23 @@ static int cs_etm__sample(struct cs_etm_queue *etmq)
                etmq->period_instructions = instrs_over;
        }
 
-       if (etm->sample_branches &&
-           etmq->prev_packet &&
-           etmq->prev_packet->sample_type == CS_ETM_RANGE &&
-           etmq->prev_packet->last_instr_taken_branch) {
-               ret = cs_etm__synth_branch_sample(etmq);
-               if (ret)
-                       return ret;
+       if (etm->sample_branches && etmq->prev_packet) {
+               bool generate_sample = false;
+
+               /* Generate sample for tracing on packet */
+               if (etmq->prev_packet->sample_type == CS_ETM_TRACE_ON)
+                       generate_sample = true;
+
+               /* Generate sample for branch taken packet */
+               if (etmq->prev_packet->sample_type == CS_ETM_RANGE &&
+                   etmq->prev_packet->last_instr_taken_branch)
+                       generate_sample = true;
+
+               if (generate_sample) {
+                       ret = cs_etm__synth_branch_sample(etmq);
+                       if (ret)
+                               return ret;
+               }
        }
 
        if (etm->sample_branches || etm->synth_opts.last_branch) {