[PATCH v3 08/10] perf tools: Add full support for CoreSight trace decoding

From: Mathieu Poirier
Date: Wed Jan 17 2018 - 12:53:17 EST


This patch adds support for complete packet decoding, allowing
traces collected during a trace session to be decoder from the
"report" infrastructure.

Co-authored-by: Tor Jeremiassen <tor@xxxxxx>
Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
---
tools/perf/util/cs-etm.c | 166 +++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 160 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index 83eb676274b5..407095af1456 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -70,6 +70,10 @@ struct cs_etm_queue {
u64 offset;
};

+static int cs_etm__update_queues(struct cs_etm_auxtrace *etm);
+static int cs_etm__process_timeless_queues(struct cs_etm_auxtrace *etm,
+ pid_t tid, u64 time_);
+
static void cs_etm__packet_dump(const char *pkt_string)
{
const char *color = PERF_COLOR_BLUE;
@@ -145,9 +149,25 @@ static void cs_etm__dump_event(struct cs_etm_auxtrace *etm,
static int cs_etm__flush_events(struct perf_session *session,
struct perf_tool *tool)
{
- (void) session;
- (void) tool;
- return 0;
+ int ret;
+ struct cs_etm_auxtrace *etm = container_of(session->auxtrace,
+ struct cs_etm_auxtrace,
+ auxtrace);
+ if (dump_trace)
+ return 0;
+
+ if (!tool->ordered_events)
+ return -EINVAL;
+
+ if (!etm->timeless_decoding)
+ return -EINVAL;
+
+ ret = cs_etm__update_queues(etm);
+
+ if (ret < 0)
+ return ret;
+
+ return cs_etm__process_timeless_queues(etm, -1, MAX_TIMESTAMP - 1);
}

static void cs_etm__free_queue(void *priv)
@@ -369,6 +389,138 @@ static int cs_etm__update_queues(struct cs_etm_auxtrace *etm)
return 0;
}

+static int
+cs_etm__get_trace(struct cs_etm_buffer *buff, struct cs_etm_queue *etmq)
+{
+ struct auxtrace_buffer *aux_buffer = etmq->buffer;
+ struct auxtrace_buffer *old_buffer = aux_buffer;
+ struct auxtrace_queue *queue;
+
+ queue = &etmq->etm->queues.queue_array[etmq->queue_nr];
+
+ aux_buffer = auxtrace_buffer__next(queue, aux_buffer);
+
+ /* If no more data, drop the previous auxtrace_buffer and return */
+ if (!aux_buffer) {
+ if (old_buffer)
+ auxtrace_buffer__drop_data(old_buffer);
+ buff->len = 0;
+ return 0;
+ }
+
+ etmq->buffer = aux_buffer;
+
+ /* If the aux_buffer doesn't have data associated, try to load it */
+ if (!aux_buffer->data) {
+ /* get the file desc associated with the perf data file */
+ int fd = perf_data__fd(etmq->etm->session->data);
+
+ aux_buffer->data = auxtrace_buffer__get_data(aux_buffer, fd);
+ if (!aux_buffer->data)
+ return -ENOMEM;
+ }
+
+ /* If valid, drop the previous buffer */
+ if (old_buffer)
+ auxtrace_buffer__drop_data(old_buffer);
+
+ buff->offset = aux_buffer->offset;
+ buff->len = aux_buffer->size;
+ buff->buf = aux_buffer->data;
+
+ buff->ref_timestamp = aux_buffer->reference;
+
+ return buff->len;
+}
+
+static void cs_etm__set_pid_tid_cpu(struct cs_etm_auxtrace *etm,
+ struct auxtrace_queue *queue)
+{
+ struct cs_etm_queue *etmq = queue->priv;
+
+ /* CPU-wide tracing isn't supported yet */
+ if (queue->tid == -1)
+ return;
+
+ if ((!etmq->thread) && (etmq->tid != -1))
+ etmq->thread = machine__find_thread(etm->machine, -1,
+ etmq->tid);
+
+ if (etmq->thread) {
+ etmq->pid = etmq->thread->pid_;
+ if (queue->cpu == -1)
+ etmq->cpu = etmq->thread->cpu;
+ }
+}
+
+static int cs_etm__run_decoder(struct cs_etm_queue *etmq)
+{
+ struct cs_etm_auxtrace *etm = etmq->etm;
+ struct cs_etm_buffer buffer;
+ size_t buffer_used, processed;
+ int err = 0;
+
+ if (!etm->kernel_start)
+ etm->kernel_start = machine__kernel_start(etm->machine);
+
+ /* Go through each buffer in the queue and decode them one by one */
+more:
+ buffer_used = 0;
+ memset(&buffer, 0, sizeof(buffer));
+ err = cs_etm__get_trace(&buffer, etmq);
+ if (err <= 0)
+ return err;
+ /*
+ * We cannot assume consecutive blocks in the data file are contiguous,
+ * reset the decoder to force re-sync.
+ */
+ err = cs_etm_decoder__reset(etmq->decoder);
+ if (err != 0)
+ return err;
+
+ /* Run trace decoder until buffer consumed or end of trace */
+ do {
+ processed = 0;
+
+ err = cs_etm_decoder__process_data_block(
+ etmq->decoder,
+ etmq->offset,
+ &buffer.buf[buffer_used],
+ buffer.len - buffer_used,
+ &processed);
+
+ if (err)
+ return err;
+
+ etmq->offset += processed;
+ buffer_used += processed;
+ } while (buffer.len > buffer_used);
+
+goto more;
+
+ return err;
+}
+
+static int cs_etm__process_timeless_queues(struct cs_etm_auxtrace *etm,
+ pid_t tid, u64 time_)
+{
+ unsigned int i;
+ struct auxtrace_queues *queues = &etm->queues;
+
+ for (i = 0; i < queues->nr_queues; i++) {
+ struct auxtrace_queue *queue = &etm->queues.queue_array[i];
+ struct cs_etm_queue *etmq = queue->priv;
+
+ if (etmq && ((tid == -1) || (etmq->tid == tid))) {
+ etmq->time = time_;
+ cs_etm__set_pid_tid_cpu(etm, queue);
+ cs_etm__run_decoder(etmq);
+ }
+ }
+
+ return 0;
+}
+
static int cs_etm__process_event(struct perf_session *session,
union perf_event *event,
struct perf_sample *sample,
@@ -380,9 +532,6 @@ static int cs_etm__process_event(struct perf_session *session,
struct cs_etm_auxtrace,
auxtrace);

- /* Keep compiler happy */
- (void)event;
-
if (dump_trace)
return 0;

@@ -405,6 +554,11 @@ static int cs_etm__process_event(struct perf_session *session,
return err;
}

+ if (event->header.type == PERF_RECORD_EXIT)
+ return cs_etm__process_timeless_queues(etm,
+ event->fork.tid,
+ sample->time);
+
return 0;
}

--
2.7.4