Add support for CPU-wide trace scenarios by correlating range packets with timestamp packets. That way range packets received on different ETMQ/traceID channels can be processed and synthesized in chronological order.
Signed-off-by: Mathieu Poirier mathieu.poirier@linaro.org --- tools/perf/util/cs-etm.c | 254 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 246 insertions(+), 8 deletions(-)
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index 79978f4428b0..8496190ad553 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -89,12 +89,26 @@ struct cs_etm_queue { };
static int cs_etm__update_queues(struct cs_etm_auxtrace *etm); +static int cs_etm__process_queues(struct cs_etm_auxtrace *etm); static int cs_etm__process_timeless_queues(struct cs_etm_auxtrace *etm, pid_t tid); +static int cs_etm__get_data_block(struct cs_etm_queue *etmq); +static int cs_etm__decode_data_block(struct cs_etm_queue *etmq);
/* PTMs ETMIDR [11:8] set to b0011 */ #define ETMIDR_PTM_VERSION 0x00000300
+/* + * A struct auxtrace_heap_item only has a queue_nr and a timestamp to + * work with. One option is to modify to auxtrace_heap_XYZ() API or simply + * encode the etm queue number as the upper 16 bit and the channel as + * the lower 16 bit. + */ +#define TO_CS_QUEUE_NR(queue_nr, trace_id_chan) \ + (queue_nr << 16 | trace_chan_id) +#define TO_QUEUE_NR(cs_queue_nr) (cs_queue_nr >> 16) +#define TO_TRACE_CHAN_ID(cs_queue_nr) (cs_queue_nr & 0x0000ffff) + static u32 cs_etm__get_v7_protocol_version(u32 etmidr) { etmidr &= ETMIDR_PTM_VERSION; @@ -146,6 +160,29 @@ void cs_etm__etmq_set_traceid_queue_timestamp(struct cs_etm_queue *etmq, etmq->pending_timestamp = trace_chan_id; }
+static u64 cs_etm__etmq_get_timestamp(struct cs_etm_queue *etmq, + u8 *trace_chan_id) +{ + struct cs_etm_packet_queue *packet_queue; + + if (!etmq->pending_timestamp) + return 0; + + if (trace_chan_id) + *trace_chan_id = etmq->pending_timestamp; + + packet_queue = cs_etm__etmq_get_packet_queue(etmq, + etmq->pending_timestamp); + if (!packet_queue) + return 0; + + /* Acknowledge pending status */ + etmq->pending_timestamp = 0; + + /* See function cs_etm_decoder__do_{hard|soft}_timestamp() */ + return packet_queue->timestamp; +} + static void cs_etm__clear_packet_queue(struct cs_etm_packet_queue *queue) { int i; @@ -170,6 +207,20 @@ static void cs_etm__clear_packet_queue(struct cs_etm_packet_queue *queue) } }
+static void cs_etm__clear_all_packet_queues(struct cs_etm_queue *etmq) +{ + int idx; + struct int_node *inode; + struct cs_etm_traceid_queue *tidq; + struct intlist *traceid_queues_list = etmq->traceid_queues_list; + + intlist__for_each_entry(inode, traceid_queues_list) { + idx = (int)(intptr_t)inode->priv; + tidq = etmq->traceid_queues[idx]; + cs_etm__clear_packet_queue(&tidq->packet_queue); + } +} + static int cs_etm__init_traceid_queue(struct cs_etm_queue *etmq, struct cs_etm_traceid_queue *tidq, u8 trace_chan_id) @@ -457,15 +508,15 @@ static int cs_etm__flush_events(struct perf_session *session, 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); + if (etm->timeless_decoding) + return cs_etm__process_timeless_queues(etm, -1); + + return cs_etm__process_queues(etm); }
static void cs_etm__free_traceid_queues(struct cs_etm_queue *etmq) @@ -684,6 +735,9 @@ static int cs_etm__setup_queue(struct cs_etm_auxtrace *etm, unsigned int queue_nr) { int ret = 0; + unsigned int cs_queue_nr; + u8 trace_chan_id; + u64 timestamp; struct cs_etm_queue *etmq = queue->priv;
if (list_empty(&queue->head) || etmq) @@ -701,6 +755,67 @@ static int cs_etm__setup_queue(struct cs_etm_auxtrace *etm, etmq->queue_nr = queue_nr; etmq->offset = 0;
+ if (etm->timeless_decoding) + goto out; + + /* + * We are under a CPU-wide trace scenario. As such we need to know + * when the code that generated the traces started to execute so that + * it can be correlated with execution on other CPUs. So we get a + * handle on the beginning of traces and decode until we find a + * timestamp. The timestamp is then added to the auxtrace min heap + * in order to know what nibble (of all the etmqs) to decode first. + */ + while (1) { + /* + * Fetch an aux_buffer from this etmq. Bail if no more + * blocks or an error has been encountered. + */ + ret = cs_etm__get_data_block(etmq); + if (ret <= 0) + goto out; + + /* + * Run decoder on the trace block. The decoder will stop when + * encountering a timestamp, a full packet queue or the end of + * trace for that block. + */ + ret = cs_etm__decode_data_block(etmq); + if (ret) + goto out; + + /* + * Function cs_etm_decoder__do_{hard|soft}_timestamp() does all + * the timestamp calculation for us. + */ + timestamp = cs_etm__etmq_get_timestamp(etmq, &trace_chan_id); + + /* We found a timestamp, no need to continue. */ + if (timestamp) + break; + + /* + * We didn't find a timestamp so empty all the traceid packet + * queues before looking for another timestamp packet, either + * in the current data block or a new one. Packets that were + * just decoded are useless since no timestamp has been + * associated with them. As such simply discard them. + */ + cs_etm__clear_all_packet_queues(etmq); + } + + /* + * We have a timestamp. Add it to the min heap to reflect when + * instructions conveyed by the range packets of this traceID queue + * started to execute. Once the same has been done for all the traceID + * queues of each etmq, redenring and decoding can start in + * chronological order. + * + * Note that packets decoded above are still in the traceID's packet + * queue and will be processed in cs_etm__process_queues(). + */ + cs_queue_nr = TO_CS_QUEUE_NR(queue_nr, trace_id_chan); + ret = auxtrace_heap__add(&etm->heap, cs_queue_nr, timestamp); out: return ret; } @@ -1849,6 +1964,28 @@ static int cs_etm__process_traceid_queue(struct cs_etm_queue *etmq, return ret; }
+static void cs_etm__clear_all_traceid_queues(struct cs_etm_queue *etmq) +{ + int idx; + struct int_node *inode; + struct cs_etm_traceid_queue *tidq; + struct intlist *traceid_queues_list = etmq->traceid_queues_list; + + intlist__for_each_entry(inode, traceid_queues_list) { + idx = (int)(intptr_t)inode->priv; + tidq = etmq->traceid_queues[idx]; + + /* Ignore return value */ + cs_etm__process_traceid_queue(etmq, tidq); + + /* + * Generate an instruction sample with the remaining + * branchstack entries. + */ + cs_etm__flush(etmq, tidq); + } +} + static int cs_etm__run_decoder(struct cs_etm_queue *etmq) { int err = 0; @@ -1916,6 +2053,105 @@ static int cs_etm__process_timeless_queues(struct cs_etm_auxtrace *etm, return 0; }
+static int cs_etm__process_queues(struct cs_etm_auxtrace *etm) +{ + int ret = 0; + unsigned int cs_queue_nr, queue_nr; + u8 trace_chan_id; + u64 timestamp; + struct auxtrace_queue *queue; + struct cs_etm_queue *etmq; + struct cs_etm_traceid_queue *tidq; + + while (1) { + if (!etm->heap.heap_cnt) + goto out; + + /* Take the entry at the top of the min heap */ + cs_queue_nr = etm->heap.heap_array[0].queue_nr; + queue_nr = TO_QUEUE_NR(cs_queue_nr); + trace_chan_id = TO_TRACE_CHAN_ID(cs_queue_nr); + queue = &etm->queues.queue_array[queue_nr]; + etmq = queue->priv; + + /* + * Remove the top entry from the heap since we are about + * to process it. + */ + auxtrace_heap__pop(&etm->heap); + + tidq = cs_etm__etmq_get_traceid_queue(etmq, trace_chan_id); + if (!tidq) { + /* + * No traceID queue has been allocated for this traceID, + * which means something somewhere went very wrong. No + * other choice than simply exit. + */ + ret = -EINVAL; + goto out; + } + + /* + * Packets associated with this timestamp are already in + * the etmq's traceID queue, so process them. + */ + ret = cs_etm__process_traceid_queue(etmq, tidq); + if (ret < 0) + goto out; + + /* + * Packets for this timestamp have been processed, time to + * move on to the next timestamp, fetching a new auxtrace_buffer + * if need be. + */ +refetch: + ret = cs_etm__get_data_block(etmq); + if (ret < 0) + goto out; + + /* + * No more auxtrace_buffers to process in this etmq, simply + * move on to another entry in the auxtrace_heap. + */ + if (!ret) + continue; + + ret = cs_etm__decode_data_block(etmq); + if (ret) + goto out; + + timestamp = cs_etm__etmq_get_timestamp(etmq, &trace_chan_id); + + if (!timestamp) { + /* + * Function cs_etm__decode_data_block() returns when + * there is no more traces to decode in the current + * auxtrace_buffer OR when a timestamp has been + * encountered on any of the traceID queues. Since we + * did not get a timestamp, there is no more traces to + * process in this auxtrace_buffer. As such empty and + * flush all traceID queues. + */ + cs_etm__clear_all_traceid_queues(etmq); + + /* Fetch another auxtrace_buffer for this etmq */ + goto refetch; + } + + /* + * Add to the min heap the timestamp for packets that have + * just been decoded. They will be processed and synthesized + * during the next call to cs_etm__process_traceid_queue() for + * this queue/traceID. + */ + cs_queue_nr = TO_CS_QUEUE_NR(queue_nr, trace_chan_id); + ret = auxtrace_heap__add(&etm->heap, cs_queue_nr, timestamp); + } + +out: + return ret; +} + static int cs_etm__process_itrace_start(struct cs_etm_auxtrace *etm, union perf_event *event) { @@ -1994,9 +2230,6 @@ static int cs_etm__process_event(struct perf_session *session, return -EINVAL; }
- if (!etm->timeless_decoding) - return -EINVAL; - if (sample->time && (sample->time != (u64) -1)) timestamp = sample->time; else @@ -2008,7 +2241,8 @@ static int cs_etm__process_event(struct perf_session *session, return err; }
- if (event->header.type == PERF_RECORD_EXIT) + if (etm->timeless_decoding && + event->header.type == PERF_RECORD_EXIT) return cs_etm__process_timeless_queues(etm, event->fork.tid);
@@ -2017,6 +2251,10 @@ static int cs_etm__process_event(struct perf_session *session, else if (event->header.type == PERF_RECORD_SWITCH_CPU_WIDE) return cs_etm__process_switch_cpu_wide(etm, event);
+ if (!etm->timeless_decoding && + event->header.type == PERF_RECORD_AUX) + return cs_etm__process_queues(etm); + return 0; }