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Message-Id: <20180216191746.11095-29-acme@kernel.org>
Date: Fri, 16 Feb 2018 16:17:33 -0300
From: Arnaldo Carvalho de Melo <acme@...nel.org>
To: Ingo Molnar <mingo@...nel.org>
Cc: linux-kernel@...r.kernel.org, linux-perf-users@...r.kernel.org,
Robert Walker <robert.walker@....com>,
coresight@...ts.linaro.org, linux-arm-kernel@...ts.infradead.org,
Arnaldo Carvalho de Melo <acme@...hat.com>
Subject: [PATCH 28/41] perf inject: Emit instruction records on ETM trace discontinuity
From: Robert Walker <robert.walker@....com>
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@....com>
Acked-by: Mathieu Poirier <mathieu.poirier@...aro.org>
Cc: coresight@...ts.linaro.org
Cc: linux-arm-kernel@...ts.infradead.org
Link: http://lkml.kernel.org/r/1518607481-4059-3-git-send-email-robert.walker@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.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 | 80 ++++++++++++++++++-------
3 files changed, 67 insertions(+), 23 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 8ff69dfd725a..640af88331b4 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);
decoder->trace_on = true;
break;
case OCSD_GEN_TRC_ELEM_INSTR_RANGE:
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 a4fdd285b145..743f5f444304 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 6e595d96c04d..1b0d422373be 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -867,6 +867,7 @@ static int cs_etm__sample(struct cs_etm_queue *etmq)
*/
if (etm->synth_opts.last_branch &&
etmq->prev_packet &&
+ etmq->prev_packet->sample_type == CS_ETM_RANGE &&
etmq->prev_packet->last_instr_taken_branch)
cs_etm__update_last_branch_rb(etmq);
@@ -920,6 +921,40 @@ 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;
@@ -971,32 +1006,31 @@ 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;
+ }
}
} while (buffer.len > buffer_used);
- /*
- * 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;
--
2.14.3
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