[PATCH AUTOSEL 5.4 164/330] perf cs-etm: Swap packets for instruction samples

Sasha Levin sashal at kernel.org
Thu Sep 17 21:58:24 EDT 2020


From: Leo Yan <leo.yan at linaro.org>

[ Upstream commit d01751563caf0dec7be36f81de77cc0197b77e59 ]

If use option '--itrace=iNNN' with Arm CoreSight trace data, perf tool
fails inject instruction samples; the root cause is the packets are only
swapped for branch samples and last branches but not for instruction
samples, so the new coming packets cannot be properly handled for only
synthesizing instruction samples.

To fix this issue, this patch refactors the code with a new function
cs_etm__packet_swap() which is used to swap packets and adds the
condition for instruction samples.

Signed-off-by: Leo Yan <leo.yan at linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier at linaro.org>
Reviewed-by: Mike Leach <mike.leach at linaro.org>
Cc: Alexander Shishkin <alexander.shishkin at linux.intel.com>
Cc: Jiri Olsa <jolsa at redhat.com>
Cc: Mark Rutland <mark.rutland at arm.com>
Cc: Namhyung Kim <namhyung at kernel.org>
Cc: Peter Zijlstra <peterz at infradead.org>
Cc: Robert Walker <robert.walker at arm.com>
Cc: Suzuki Poulouse <suzuki.poulose at arm.com>
Cc: coresight ml <coresight at lists.linaro.org>
Cc: linux-arm-kernel at lists.infradead.org
Link: http://lore.kernel.org/lkml/20200219021811.20067-2-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme at redhat.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 tools/perf/util/cs-etm.c | 39 +++++++++++++++++++--------------------
 1 file changed, 19 insertions(+), 20 deletions(-)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index f5f855fff412e..38298cbb07524 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -363,6 +363,23 @@ struct cs_etm_packet_queue
 	return NULL;
 }
 
+static void cs_etm__packet_swap(struct cs_etm_auxtrace *etm,
+				struct cs_etm_traceid_queue *tidq)
+{
+	struct cs_etm_packet *tmp;
+
+	if (etm->sample_branches || etm->synth_opts.last_branch ||
+	    etm->sample_instructions) {
+		/*
+		 * Swap PACKET with PREV_PACKET: PACKET becomes PREV_PACKET for
+		 * the next incoming packet.
+		 */
+		tmp = tidq->packet;
+		tidq->packet = tidq->prev_packet;
+		tidq->prev_packet = tmp;
+	}
+}
+
 static void cs_etm__packet_dump(const char *pkt_string)
 {
 	const char *color = PERF_COLOR_BLUE;
@@ -1340,7 +1357,6 @@ static int cs_etm__sample(struct cs_etm_queue *etmq,
 			  struct cs_etm_traceid_queue *tidq)
 {
 	struct cs_etm_auxtrace *etm = etmq->etm;
-	struct cs_etm_packet *tmp;
 	int ret;
 	u8 trace_chan_id = tidq->trace_chan_id;
 	u64 instrs_executed = tidq->packet->instr_count;
@@ -1404,15 +1420,7 @@ static int cs_etm__sample(struct cs_etm_queue *etmq,
 		}
 	}
 
-	if (etm->sample_branches || etm->synth_opts.last_branch) {
-		/*
-		 * Swap PACKET with PREV_PACKET: PACKET becomes PREV_PACKET for
-		 * the next incoming packet.
-		 */
-		tmp = tidq->packet;
-		tidq->packet = tidq->prev_packet;
-		tidq->prev_packet = tmp;
-	}
+	cs_etm__packet_swap(etm, tidq);
 
 	return 0;
 }
@@ -1441,7 +1449,6 @@ static int cs_etm__flush(struct cs_etm_queue *etmq,
 {
 	int err = 0;
 	struct cs_etm_auxtrace *etm = etmq->etm;
-	struct cs_etm_packet *tmp;
 
 	/* Handle start tracing packet */
 	if (tidq->prev_packet->sample_type == CS_ETM_EMPTY)
@@ -1476,15 +1483,7 @@ static int cs_etm__flush(struct cs_etm_queue *etmq,
 	}
 
 swap_packet:
-	if (etm->sample_branches || etm->synth_opts.last_branch) {
-		/*
-		 * Swap PACKET with PREV_PACKET: PACKET becomes PREV_PACKET for
-		 * the next incoming packet.
-		 */
-		tmp = tidq->packet;
-		tidq->packet = tidq->prev_packet;
-		tidq->prev_packet = tmp;
-	}
+	cs_etm__packet_swap(etm, tidq);
 
 	return err;
 }
-- 
2.25.1




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