If one CS_ETM_TRACE_ON packet is inserted, we miss to handle it for branch samples. CS_ETM_TRACE_ON packet itself can give the info that there have a discontinuity in the trace, furthermore we also miss to generate branch sample for packets before and after CS_ETM_TRACE_ON packet.
This patch is to add branch sample handling if CS_ETM_TRACE_ON packet is inserted in the middle of CS_ETM_RANGE packets:
If there has one CS_ETM_TRACE_ON packet is coming, we firstly generate branch sample in the function cs_etm__flush(), this can save complete info for the previous CS_ETM_RANGE packet just before CS_ETM_TRACE_ON packet. We also generate branch sample for the new CS_ETM_RANGE packet after CS_ETM_TRACE_ON packet, this have two purposes, the first one purpose is to save the info for the new CS_ETM_RANGE packet, the second purpose is to save CS_ETM_TRACE_ON packet info so we can have hint for a discontinuity in the trace.
For CS_ETM_TRACE_ON packet, its fields 'packet->start_addr' and 'packet->end_addr' equal to 0xdeadbeefdeadbeefUL which are emitted in the decoder layer as dummy value. This patch is to convert these values to zeros for more readable; this is accomplished by functions cs_etm__last_executed_instr() and cs_etm__first_executed_instr(). The later one is a new function introduced by this patch.
Reviewed-by: Robert Walker robert.walker@arm.com Signed-off-by: Leo Yan leo.yan@linaro.org --- tools/perf/util/cs-etm.c | 52 ++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 42 insertions(+), 10 deletions(-)
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index 67564c1..8ec2f2c 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -494,6 +494,10 @@ static inline void cs_etm__reset_last_branch_rb(struct cs_etm_queue *etmq)
static inline u64 cs_etm__last_executed_instr(struct cs_etm_packet *packet) { + /* Returns 0 for the CS_ETM_TRACE_ON packet */ + if (packet->sample_type == CS_ETM_TRACE_ON) + return 0; + /* * The packet records the execution range with an exclusive end address * @@ -505,6 +509,15 @@ static inline u64 cs_etm__last_executed_instr(struct cs_etm_packet *packet) return packet->end_addr - A64_INSTR_SIZE; }
+static inline u64 cs_etm__first_executed_instr(struct cs_etm_packet *packet) +{ + /* Returns 0 for the CS_ETM_TRACE_ON packet */ + if (packet->sample_type == CS_ETM_TRACE_ON) + return 0; + + return packet->start_addr; +} + static inline u64 cs_etm__instr_count(const struct cs_etm_packet *packet) { /* @@ -546,7 +559,7 @@ static void cs_etm__update_last_branch_rb(struct cs_etm_queue *etmq)
be = &bs->entries[etmq->last_branch_pos]; be->from = cs_etm__last_executed_instr(etmq->prev_packet); - be->to = etmq->packet->start_addr; + be->to = cs_etm__first_executed_instr(etmq->packet); /* No support for mispredict */ be->flags.mispred = 0; be->flags.predicted = 1; @@ -701,7 +714,7 @@ static int cs_etm__synth_branch_sample(struct cs_etm_queue *etmq) sample.ip = cs_etm__last_executed_instr(etmq->prev_packet); sample.pid = etmq->pid; sample.tid = etmq->tid; - sample.addr = etmq->packet->start_addr; + sample.addr = cs_etm__first_executed_instr(etmq->packet); sample.id = etmq->etm->branches_id; sample.stream_id = etmq->etm->branches_id; sample.period = 1; @@ -897,13 +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 normal branch 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) { @@ -922,6 +945,7 @@ static int cs_etm__sample(struct cs_etm_queue *etmq) static int cs_etm__flush(struct cs_etm_queue *etmq) { int err = 0; + struct cs_etm_auxtrace *etm = etmq->etm; struct cs_etm_packet *tmp;
if (!etmq->prev_packet) @@ -948,12 +972,20 @@ static int cs_etm__flush(struct cs_etm_queue *etmq) err = cs_etm__synth_instruction_sample( etmq, addr, etmq->period_instructions); + if (err) + return err; etmq->period_instructions = 0;
}
+ if (etm->sample_branches) { + err = cs_etm__synth_branch_sample(etmq); + if (err) + return err; + } + swap_packet: - if (etmq->etm->synth_opts.last_branch) { + if (etm->sample_branches || etm->synth_opts.last_branch) { /* * Swap PACKET with PREV_PACKET: PACKET becomes PREV_PACKET for * the next incoming packet.