On Sat, Jan 19, 2019 at 09:43:42AM +0800, Leo Yan wrote:
> In the middle of trace stream, it might be interrupted thus the trace
> data is not continuous, the trace stream firstly is ended for previous
> trace block and restarted for next block.
>
> To display related information for showing trace is restarted, this
> patch set sample flags for trace discontinuity:
>
> - If one discontinuity packet is coming, append flag
> PERF_IP_FLAG_TRACE_END to the previous packet to indicate the trace
> has been ended;
> - If one instruction packet is following discontinuity packet, this
> instruction packet is the first one packet to restarting trace. So
> set flag PERF_IP_FLAG_TRACE_START to discontinuity packet, this flag
> will be used to generate sample when connect with the sequential
> instruction packet.
>
> Signed-off-by: Leo Yan <leo....@linaro.org>
> ---
> tools/perf/util/cs-etm.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
> index d05cac5295f1..1aa29633ce77 100644
> --- a/tools/perf/util/cs-etm.c
> +++ b/tools/perf/util/cs-etm.c
> @@ -1111,6 +1111,7 @@ static int cs_etm__end_block(struct cs_etm_queue *etmq)
> static int cs_etm__set_sample_flags(struct cs_etm_queue *etmq)
> {
> struct cs_etm_packet *packet = etmq->packet;
> + struct cs_etm_packet *prev_packet = etmq->prev_packet;
>
> switch (packet->sample_type) {
> case CS_ETM_RANGE:
> @@ -1170,8 +1171,26 @@ static int cs_etm__set_sample_flags(struct
> cs_etm_queue *etmq)
> packet->last_instr_subtype == OCSD_S_INSTR_V8_RET)
> packet->flags = PERF_IP_FLAG_BRANCH |
> PERF_IP_FLAG_RETURN;
> +
> + /*
> + * Decoder might insert a discontinuity in the middle of
> + * instruction packets, fixup prev_packet with flag
> + * PERF_IP_FLAG_TRACE_BEGIN to indicate restarting trace.
> + */
> + if (prev_packet->sample_type == CS_ETM_DISCONTINUITY)
> + prev_packet->flags |= PERF_IP_FLAG_BRANCH |
> + PERF_IP_FLAG_TRACE_BEGIN;
> break;
> case CS_ETM_DISCONTINUITY:
> + /*
> + * The trace is discontinuous, if the previous packet is
> + * instruction packet, set flag PERF_IP_FLAG_TRACE_END
> + * for previous packet.
> + */
> + if (prev_packet->sample_type == CS_ETM_RANGE)
> + prev_packet->flags |= PERF_IP_FLAG_BRANCH |
> + PERF_IP_FLAG_TRACE_END;
> + break;
> case CS_ETM_EXCEPTION:
> case CS_ETM_EXCEPTION_RET:
> case CS_ETM_EMPTY:
Reviewed-by: Mathieu Poirier <mathieu.poir...@linaro.org>
> --
> 2.17.1
>
