On Wed, Feb 07, 2018 at 01:57:25PM +0000, Robert Walker wrote:
There may be discontinuities in the ETM trace stream due to overflows or ETM configuration for selective trace. This patch emits an instruction sample with the pending branch stack when a TRACE ON packet occurs indicating a discontinuity in the trace data.
A new packet type CS_ETM_TRACE_ON is added, which is emitted by the low level decoder when a TRACE ON occurs. The higher level decoder flushes the branch stack when this packet is emitted.
Signed-off-by: Robert Walker robert.walker@arm.com
tools/perf/util/cs-etm-decoder/cs-etm-decoder.c | 9 +++ tools/perf/util/cs-etm-decoder/cs-etm-decoder.h | 1 + tools/perf/util/cs-etm.c | 84 +++++++++++++++++-------- 3 files changed, 69 insertions(+), 25 deletions(-)
diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c index 8ff69df..640af88 100644 --- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c +++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c @@ -328,7 +328,14 @@ cs_etm_decoder__buffer_range(struct cs_etm_decoder *decoder, } return ret; +} +static ocsd_datapath_resp_t +cs_etm_decoder__buffer_trace_on(struct cs_etm_decoder *decoder,
const uint8_t trace_chan_id)+{
- return cs_etm_decoder__buffer_packet(decoder, trace_chan_id,
CS_ETM_TRACE_ON);} static ocsd_datapath_resp_t cs_etm_decoder__gen_trace_elem_printer( @@ -347,6 +354,8 @@ static ocsd_datapath_resp_t cs_etm_decoder__gen_trace_elem_printer( decoder->trace_on = false; break; case OCSD_GEN_TRC_ELEM_TRACE_ON:
resp = cs_etm_decoder__buffer_trace_on(decoder,trace_chan_id);diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h index a4fdd28..743f5f4 100644 --- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h +++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h @@ -24,6 +24,7 @@ struct cs_etm_buffer { enum cs_etm_sample_type { CS_ETM_RANGE = 1 << 0,
- CS_ETM_TRACE_ON = 1 << 1,
}; struct cs_etm_packet { diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index 6777246..a8d07bd 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -866,6 +866,8 @@ static int cs_etm__sample(struct cs_etm_queue *etmq) * PREV_PACKET is a branch. */ if (etm->synth_opts.last_branch &&
etmq->prev_packet &&etmq->prev_packet->sample_type == CS_ETM_RANGE && etmq->prev_packet->last_instr_taken_branch)@@ -918,6 +920,40 @@ static int cs_etm__sample(struct cs_etm_queue *etmq) return 0; } +static int cs_etm__flush(struct cs_etm_queue *etmq) +{
- int err = 0;
- struct cs_etm_packet *tmp;
- if (etmq->etm->synth_opts.last_branch &&
etmq->prev_packet &&etmq->prev_packet->sample_type == CS_ETM_RANGE) {/** Generate a last branch event for the branches left in the* circular buffer at the end of the trace.** Use the address of the end of the last reported execution* range*/u64 addr = cs_etm__last_executed_instr(etmq->prev_packet);err = cs_etm__synth_instruction_sample(etmq, addr,etmq->period_instructions);etmq->period_instructions = 0;/** Swap PACKET with PREV_PACKET: PACKET becomes PREV_PACKET for* the next incoming packet.*/tmp = etmq->packet;etmq->packet = etmq->prev_packet;etmq->prev_packet = tmp;- }
- return err;
+}
static int cs_etm__run_decoder(struct cs_etm_queue *etmq) { struct cs_etm_auxtrace *etm = etmq->etm; @@ -946,20 +982,19 @@ static int cs_etm__run_decoder(struct cs_etm_queue *etmq) /* Run trace decoder until buffer consumed or end of trace */ do { processed = 0;
this...
err = cs_etm_decoder__process_data_block( etmq->decoder, etmq->offset, &buffer.buf[buffer_used], buffer.len - buffer_used, &processed);
and this should have gone in the first patch.
if (err) return err;etmq->offset += processed; buffer_used += processed;
/* Process each packet in this chunk */
And probably this too.
With the above changes:
Acked-by: Mathieu Poirier mathieu.poirier@linaro.org
while (1) { err = cs_etm_decoder__get_packet(etmq->decoder, etmq->packet);@@ -970,32 +1005,31 @@ static int cs_etm__run_decoder(struct cs_etm_queue *etmq) */ break;
/** If the packet contains an instruction* range, generate instruction sequence* events.*/if (etmq->packet->sample_type & CS_ETM_RANGE)err = cs_etm__sample(etmq);
switch (etmq->packet->sample_type) {case CS_ETM_RANGE:/** If the packet contains an instruction* range, generate instruction sequence* events.*/cs_etm__sample(etmq);break;case CS_ETM_TRACE_ON:/** Discontinuity in trace, flush* previous branch stack*/cs_etm__flush(etmq);break;default:break;} }
/** Generate a last branch event for the branches left in* the circular buffer at the end of the trace.*/if (etm->sample_instructions &&etmq->etm->synth_opts.last_branch) {struct branch_stack *bs = etmq->last_branch_rb;struct branch_entry *be =&bs->entries[etmq->last_branch_pos];err = cs_etm__synth_instruction_sample(etmq, be->to, etmq->period_instructions);if (err)return err;}
if (err == 0)/* Flush any remaining branch stack entries */err = cs_etm__flush(etmq);return err; -- 2.7.4