Thread (7 messages) 7 messages, 3 authors, 2021-11-17

Re: [PATCH 1/1] perf arm-spe: Inject SPE samples in perf-inject

From: Arnaldo Carvalho de Melo <acme@kernel.org>
Date: 2021-11-17 15:29:49
Also in: linux-perf-users, lkml

Em Mon, Nov 08, 2021 at 08:39:58PM +0000, James Clark escreveu:

On 05/11/2021 10:41, German Gomez wrote:
quoted
Inject synthesized SPE samples during perf-inject run.

Signed-off-by: German Gomez <redacted>
Reviewed-by: James Clark <redacted>
Next time please expand this explanations a bit more: why should we
inject such samples? Is this enabling some new mode of operation, fixing
something, what is an example of output before this patch and after it?

- Arnaldo
quoted
---
 tools/perf/util/arm-spe.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c
index 58b7069c5..7054f2315 100644
--- a/tools/perf/util/arm-spe.c
+++ b/tools/perf/util/arm-spe.c
@@ -51,6 +51,7 @@ struct arm_spe {
 	u8				timeless_decoding;
 	u8				data_queued;
 
+	u64				sample_type;
 	u8				sample_flc;
 	u8				sample_llc;
 	u8				sample_tlb;
@@ -248,6 +249,12 @@ static void arm_spe_prep_sample(struct arm_spe *spe,
 	event->sample.header.size = sizeof(struct perf_event_header);
 }
 
+static int arm_spe__inject_event(union perf_event *event, struct perf_sample *sample, u64 type)
+{
+	event->header.size = perf_event__sample_event_size(sample, type, 0);
+	return perf_event__synthesize_sample(event, type, 0, sample);
+}
+
 static inline int
 arm_spe_deliver_synth_event(struct arm_spe *spe,
 			    struct arm_spe_queue *speq __maybe_unused,
@@ -256,6 +263,12 @@ arm_spe_deliver_synth_event(struct arm_spe *spe,
 {
 	int ret;
 
+	if (spe->synth_opts.inject) {
+		ret = arm_spe__inject_event(event, sample, spe->sample_type);
+		if (ret)
+			return ret;
+	}
+
 	ret = perf_session__deliver_synth_event(spe->session, event, sample);
 	if (ret)
 		pr_err("ARM SPE: failed to deliver event, error %d\n", ret);
@@ -920,6 +933,8 @@ arm_spe_synth_events(struct arm_spe *spe, struct perf_session *session)
 	else
 		attr.sample_type |= PERF_SAMPLE_TIME;
 
+	spe->sample_type = attr.sample_type;
+
 	attr.exclude_user = evsel->core.attr.exclude_user;
 	attr.exclude_kernel = evsel->core.attr.exclude_kernel;
 	attr.exclude_hv = evsel->core.attr.exclude_hv;
-- 

- Arnaldo

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