[PATCH 4/4] perf cs_etm: Set the time field in the synthetic samples
German Gomez
german.gomez at arm.com
Wed May 4 08:02:15 PDT 2022
If virtual timestamps are detected, set sample time field accordingly,
otherwise warn the user that the samples will not include the time data.
| Test notes (FEAT_TRF platform)
|
| $ ./perf record -e cs_etm//u -a -- sleep 4
| $ ./perf script --fields +time
| perf 422 [000] 163.375100: 1 branches:uH: 0 [unknown] ([unknown])
| perf 422 [000] 163.375100: 1 branches:uH: ffffb8009544 ioctl+0x14 (/lib/aarch64-linux-gnu/libc-2.27.so)
| perf 422 [000] 163.375100: 1 branches:uH: aaaaab6bebf4 perf_evsel__run_ioctl+0x90 (/home/german/linux/tools/perf/perf)
| [...]
| perf 422 [000] 167.393100: 1 branches:uH: aaaaab6bda00 __xyarray__entry+0x74 (/home/german/linux/tools/perf/perf)
| perf 422 [000] 167.393099: 1 branches:uH: aaaaab6bda0c __xyarray__entry+0x80 (/home/german/linux/tools/perf/perf)
| perf 422 [000] 167.393099: 1 branches:uH: ffffb8009538 ioctl+0x8 (/lib/aarch64-linux-gnu/libc-2.27.so)
|
| The time from the first sample to the last sample is 4 seconds
Signed-off-by: German Gomez <german.gomez at arm.com>
---
tools/perf/util/cs-etm.c | 80 ++++++++++++++++++++++++++++++++++++++--
1 file changed, 76 insertions(+), 4 deletions(-)
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index e883ef6d9c75..ace4ba3256df 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -35,6 +35,7 @@
#include "tool.h"
#include "thread.h"
#include "thread-stack.h"
+#include "tsc.h"
#include <tools/libc_compat.h>
#include "util/synthetic-events.h"
@@ -46,10 +47,12 @@ struct cs_etm_auxtrace {
struct perf_session *session;
struct machine *machine;
struct thread *unknown_thread;
+ struct perf_tsc_conversion tc;
u8 timeless_decoding;
u8 snapshot_mode;
u8 data_queued;
+ u8 has_virtual_ts; /* Virtual/Kernel timestamps in the trace. */
int num_cpu;
u64 latest_kernel_timestamp;
@@ -1161,6 +1164,22 @@ static void cs_etm__copy_insn(struct cs_etm_queue *etmq,
sample->insn_len, (void *)sample->insn);
}
+static inline void cs_etm__resolve_sample_time(struct cs_etm_queue *etmq,
+ struct cs_etm_traceid_queue *tidq,
+ u64 *time)
+{
+ struct cs_etm_auxtrace *etm = etmq->etm;
+ struct cs_etm_packet_queue *packet_queue = &tidq->packet_queue;
+
+ if (etm->timeless_decoding)
+ *time = 0;
+ else if (etm->has_virtual_ts)
+ *time = tsc_to_perf_time(packet_queue->cs_timestamp, &etm->tc);
+ else
+ *time = etm->latest_kernel_timestamp;
+
+}
+
static int cs_etm__synth_instruction_sample(struct cs_etm_queue *etmq,
struct cs_etm_traceid_queue *tidq,
u64 addr, u64 period)
@@ -1174,8 +1193,9 @@ static int cs_etm__synth_instruction_sample(struct cs_etm_queue *etmq,
event->sample.header.misc = cs_etm__cpu_mode(etmq, addr);
event->sample.header.size = sizeof(struct perf_event_header);
- if (!etm->timeless_decoding)
- sample.time = etm->latest_kernel_timestamp;
+ /* Set time field based con etm auxtrace config. */
+ cs_etm__resolve_sample_time(etmq, tidq, &sample.time);
+
sample.ip = addr;
sample.pid = tidq->pid;
sample.tid = tidq->tid;
@@ -1232,8 +1252,9 @@ static int cs_etm__synth_branch_sample(struct cs_etm_queue *etmq,
event->sample.header.misc = cs_etm__cpu_mode(etmq, ip);
event->sample.header.size = sizeof(struct perf_event_header);
- if (!etm->timeless_decoding)
- sample.time = etm->latest_kernel_timestamp;
+ /* Set time field based con etm auxtrace config. */
+ cs_etm__resolve_sample_time(etmq, tidq, &sample.time);
+
sample.ip = ip;
sample.pid = tidq->pid;
sample.tid = tidq->tid;
@@ -2899,12 +2920,46 @@ static int cs_etm__queue_aux_records(struct perf_session *session)
return 0;
}
+/*
+ * Loop through the ETMs and complain if we find at least one where ts_source != 1 (virtual
+ * timestamps).
+ */
+static bool cs_etm__has_virtual_ts(u64 **metadata, int num_cpu)
+{
+ int j;
+
+ for (j = 0; j < num_cpu; j++) {
+
+#define HAS_PARAM(j, type, param) (metadata[(j)][CS_ETM_NR_TRC_PARAMS] <= (CS_##type##_##param - CS_ETM_COMMON_BLK_MAX_V1))
+
+ switch (metadata[j][CS_ETM_MAGIC]) {
+ case __perf_cs_etmv4_magic:
+ if (HAS_PARAM(j, ETMV4, TS_SOURCE) || metadata[j][CS_ETMV4_TS_SOURCE] != 1)
+ return false;
+ break;
+ case __perf_cs_ete_magic:
+ if (HAS_PARAM(j, ETE, TS_SOURCE) || metadata[j][CS_ETE_TS_SOURCE] != 1)
+ return false;
+ break;
+ default:
+ /* Unknown / unsupported magic number. */
+ return false;
+ }
+
+#undef HAS_PARAM
+
+ }
+
+ return true;
+}
+
int cs_etm__process_auxtrace_info(union perf_event *event,
struct perf_session *session)
{
struct perf_record_auxtrace_info *auxtrace_info = &event->auxtrace_info;
struct cs_etm_auxtrace *etm = NULL;
struct int_node *inode;
+ struct perf_record_time_conv *tc = &session->time_conv;
unsigned int pmu_type;
int event_header_size = sizeof(struct perf_event_header);
int info_header_size;
@@ -3071,6 +3126,13 @@ int cs_etm__process_auxtrace_info(union perf_event *event,
etm->auxtrace_type = auxtrace_info->type;
etm->timeless_decoding = cs_etm__is_timeless_decoding(etm);
+ /* Use virtual timestamps if all ETMs report ts_source = 1 */
+ etm->has_virtual_ts = cs_etm__has_virtual_ts(metadata, num_cpu);
+
+ if (!etm->has_virtual_ts)
+ ui__warning("Virtual timestamps are not enabled, or not supported by the traced system.\n\n"
+ "The time field of the samples will not be set.\n\n");
+
etm->auxtrace.process_event = cs_etm__process_event;
etm->auxtrace.process_auxtrace_event = cs_etm__process_auxtrace_event;
etm->auxtrace.flush_events = cs_etm__flush_events;
@@ -3100,6 +3162,16 @@ int cs_etm__process_auxtrace_info(union perf_event *event,
goto err_delete_thread;
}
+ etm->tc.time_shift = tc->time_shift;
+ etm->tc.time_mult = tc->time_mult;
+ etm->tc.time_zero = tc->time_zero;
+ if (event_contains(*tc, time_cycles)) {
+ etm->tc.time_cycles = tc->time_cycles;
+ etm->tc.time_mask = tc->time_mask;
+ etm->tc.cap_user_time_zero = tc->cap_user_time_zero;
+ etm->tc.cap_user_time_short = tc->cap_user_time_short;
+ }
+
if (dump_trace) {
cs_etm__print_auxtrace_info(auxtrace_info->priv, num_cpu);
}
--
2.25.1
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