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....@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:
/*
--
2.7.4
