[PATCH 08/12] perf tools: Support PERF_SAMPLE_WEIGHT_EXT

From: kan . liang
Date: Tue Jan 19 2021 - 15:48:52 EST


From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>

The new sample type, PERF_SAMPLE_WEIGHT_EXT, is an extension of the
PERF_SAMPLE_WEIGHT sample type. Enable the sample type if the sample by
weight option is applied.

Add weight_ext in the struct perf_sample to record the value of the new
sample type. For the old kernel which doesn't support the new sample
type, clear the sample type.

Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
---
tools/perf/util/event.h | 1 +
tools/perf/util/evsel.c | 22 +++++++++++++++++++---
tools/perf/util/evsel.h | 1 +
tools/perf/util/synthetic-events.c | 8 ++++++++
4 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index ff403ea..0852c86 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -128,6 +128,7 @@ struct perf_sample {
u64 stream_id;
u64 period;
u64 weight;
+ union perf_weight_ext weight_ext;
u64 transaction;
u64 insn_cnt;
u64 cyc_cnt;
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 97acde2..bb05687 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1165,8 +1165,10 @@ void evsel__config(struct evsel *evsel, struct record_opts *opts,
attr->branch_sample_type = opts->branch_stack;
}

- if (opts->sample_weight)
+ if (opts->sample_weight) {
evsel__set_sample_bit(evsel, WEIGHT);
+ evsel__set_sample_bit(evsel, WEIGHT_EXT);
+ }

attr->task = track;
attr->mmap = track;
@@ -1735,6 +1737,8 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
}

fallback_missing_features:
+ if (perf_missing_features.weight_ext)
+ evsel__reset_sample_bit(evsel, WEIGHT_EXT);
if (perf_missing_features.clockid_wrong)
evsel->core.attr.clockid = CLOCK_MONOTONIC; /* should always work */
if (perf_missing_features.clockid) {
@@ -1873,8 +1877,13 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
* Must probe features in the order they were added to the
* perf_event_attr interface.
*/
- if (!perf_missing_features.data_page_size &&
- (evsel->core.attr.sample_type & PERF_SAMPLE_DATA_PAGE_SIZE)) {
+ if (!perf_missing_features.weight_ext &&
+ (evsel->core.attr.sample_type & PERF_SAMPLE_WEIGHT_EXT)) {
+ perf_missing_features.weight_ext = true;
+ pr_debug2("switching off weight extension support\n");
+ goto fallback_missing_features;
+ } else if (!perf_missing_features.data_page_size &&
+ (evsel->core.attr.sample_type & PERF_SAMPLE_DATA_PAGE_SIZE)) {
perf_missing_features.data_page_size = true;
pr_debug2_peo("Kernel has no PERF_SAMPLE_DATA_PAGE_SIZE support, bailing out\n");
goto out_close;
@@ -2382,6 +2391,13 @@ int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
array = (void *)array + sz;
}

+ data->weight_ext.val = 0;
+ if (type & PERF_SAMPLE_WEIGHT_EXT) {
+ OVERFLOW_CHECK_u64(array);
+ data->weight_ext.val = *array;
+ array++;
+ }
+
return 0;
}

diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index cd1d8dd..ec598a6 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -145,6 +145,7 @@ struct perf_missing_features {
bool branch_hw_idx;
bool cgroup;
bool data_page_size;
+ bool weight_ext;
};

extern struct perf_missing_features perf_missing_features;
diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
index 2947e3f..69291a9 100644
--- a/tools/perf/util/synthetic-events.c
+++ b/tools/perf/util/synthetic-events.c
@@ -1417,6 +1417,9 @@ size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type,
result += sample->aux_sample.size;
}

+ if (type & PERF_SAMPLE_WEIGHT_EXT)
+ result += sizeof(u64);
+
return result;
}

@@ -1603,6 +1606,11 @@ int perf_event__synthesize_sample(union perf_event *event, u64 type, u64 read_fo
array = (void *)array + sz;
}

+ if (type & PERF_SAMPLE_WEIGHT_EXT) {
+ *array = sample->weight_ext.val;
+ array++;
+ }
+
return 0;
}

--
2.7.4