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perf inject: Emit instruction records on ETM trace discontinuity

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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@arm.com>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.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@redhat.com>
This commit is contained in:
Robert Walker 2018-02-14 11:24:40 +00:00 committed by Arnaldo Carvalho de Melo
parent e573e978fb
commit 256e751cac
3 changed files with 67 additions and 23 deletions
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9
tools/perf/util/cs-etm-decoder/cs-etm-decoder.c
View File

@ -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:

1
tools/perf/util/cs-etm-decoder/cs-etm-decoder.h
View File

@ -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 {

80
tools/perf/util/cs-etm.c
View File

@ -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;