We have prepared the flags in the packet structure, so need to copy the related value into sample structure thus perf tool can facilitate sample flags.
The PREV_PACKET contains the branch instruction flags and PACKET actually contains the flags for next branch instruction. So this patch is to set sample flags with 'etmq->prev_packet->flags'.
This patch includes three fixing up for sample flags based on the packets context:
- If the packet is exception packet or exception return packet, update the previous packet for exception specific flags; - If there has TRACE_ON or TRACE_OFF packet in the middle of instruction packets, this indicates the trace is discontinuous, so append the flag PERF_IP_FLAG_TRACE_END to the previous packet to indicate the trace has been ended; - If one instruction packet is behind TRACE_OFF packet, this instruction is restarting trace packet. So set flag PERF_IP_FLAG_TRACE_START to TRACE_OFF packet if one, this flag isn't used by TRACE_OFF packet but used to indicate trace restarting when generate sample.
Signed-off-by: Leo Yan leo.yan@linaro.org --- tools/perf/util/cs-etm.c | 43 +++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 41 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index 455f132..afca6f3 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -676,7 +676,7 @@ static int cs_etm__synth_instruction_sample(struct cs_etm_queue *etmq, sample.stream_id = etmq->etm->instructions_id; sample.period = period; sample.cpu = etmq->packet->cpu; - sample.flags = 0; + sample.flags = etmq->prev_packet->flags; sample.insn_len = 1; sample.cpumode = event->sample.header.misc;
@@ -735,7 +735,7 @@ static int cs_etm__synth_branch_sample(struct cs_etm_queue *etmq) sample.stream_id = etmq->etm->branches_id; sample.period = 1; sample.cpu = etmq->packet->cpu; - sample.flags = 0; + sample.flags = etmq->prev_packet->flags; sample.cpumode = event->sample.header.misc;
/* @@ -878,6 +878,43 @@ static int cs_etm__synth_events(struct cs_etm_auxtrace *etm, return 0; }
+static void cs_etm__fixup_flags(struct cs_etm_queue *etmq) +{ + /* + * Decoding stream might insert one TRACE_OFF packet in the + * middle of instruction packets, this means it doesn't + * contain the pair packets with TRACE_OFF and TRACE_ON. + * For this case, the instruction packet follows with + * TRACE_OFF packet so we need to fixup prev_packet with flag + * PERF_IP_FLAG_TRACE_BEGIN, this flag finally is used by the + * instruction packet to generate samples. + */ + if (etmq->prev_packet->sample_type == CS_ETM_TRACE_OFF && + etmq->packet->sample_type == CS_ETM_RANGE) + etmq->prev_packet->flags = PERF_IP_FLAG_BRANCH | + PERF_IP_FLAG_TRACE_BEGIN; + + if (etmq->prev_packet->sample_type == CS_ETM_RANGE) { + /* + * When the exception packet is inserted, update flags + * so tell perf it is exception related branches. + */ + if (etmq->packet->sample_type == CS_ETM_EXCEPTION || + etmq->packet->sample_type == CS_ETM_EXCEPTION_RET) + etmq->prev_packet->flags = etmq->packet->flags; + + /* + * The trace is discontinuous, weather this is caused by + * TRACE_ON packet or TRACE_OFF packet is coming, if the + * previous packet is instruction packet, simply set flag + * PERF_IP_FLAG_TRACE_END for previous packet. + */ + if (etmq->packet->sample_type == CS_ETM_TRACE_ON || + etmq->packet->sample_type == CS_ETM_TRACE_OFF) + etmq->prev_packet->flags |= PERF_IP_FLAG_TRACE_END; + } +} + static int cs_etm__sample(struct cs_etm_queue *etmq) { struct cs_etm_auxtrace *etm = etmq->etm; @@ -1100,6 +1137,8 @@ static int cs_etm__run_decoder(struct cs_etm_queue *etmq) */ break;
+ cs_etm__fixup_flags(etmq); + switch (etmq->packet->sample_type) { case CS_ETM_RANGE: /*