From f52679b78877f17e95a317e18a4c9c46cc3d845a Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Thu, 18 Aug 2022 17:36:44 -0700 Subject: perf tools: Support reading PERF_FORMAT_LOST The recent kernel added lost count can be read from either read(2) or ring buffer data with PERF_SAMPLE_READ. As it's a variable length data we need to access it according to the format info. But for perf tools use cases, PERF_FORMAT_ID is always set. So we can only check PERF_FORMAT_LOST bit to determine the data format. Add sample_read_value_size() and next_sample_read_value() helpers to make it a bit easier to access. Use them in all places where it reads the struct sample_read_value. Signed-off-by: Namhyung Kim Acked-by: Jiri Olsa Cc: Ian Rogers Cc: Ingo Molnar Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20220819003644.508916-5-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/synthetic-events.c | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-) (limited to 'tools/perf/util/synthetic-events.c') diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c index 59747c440bd5..812424dbf2d5 100644 --- a/tools/perf/util/synthetic-events.c +++ b/tools/perf/util/synthetic-events.c @@ -1429,11 +1429,12 @@ size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type, result += sizeof(u64); /* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */ if (read_format & PERF_FORMAT_GROUP) { - sz = sample->read.group.nr * - sizeof(struct sample_read_value); - result += sz; + sz = sample_read_value_size(read_format); + result += sz * sample->read.group.nr; } else { result += sizeof(u64); + if (read_format & PERF_FORMAT_LOST) + result += sizeof(u64); } } @@ -1518,6 +1519,20 @@ void __weak arch_perf_synthesize_sample_weight(const struct perf_sample *data, *array = data->weight; } +static __u64 *copy_read_group_values(__u64 *array, __u64 read_format, + const struct perf_sample *sample) +{ + size_t sz = sample_read_value_size(read_format); + struct sample_read_value *v = sample->read.group.values; + + sample_read_group__for_each(v, sample->read.group.nr, read_format) { + /* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */ + memcpy(array, v, sz); + array = (void *)array + sz; + } + return array; +} + int perf_event__synthesize_sample(union perf_event *event, u64 type, u64 read_format, const struct perf_sample *sample) { @@ -1599,13 +1614,16 @@ int perf_event__synthesize_sample(union perf_event *event, u64 type, u64 read_fo /* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */ if (read_format & PERF_FORMAT_GROUP) { - sz = sample->read.group.nr * - sizeof(struct sample_read_value); - memcpy(array, sample->read.group.values, sz); - array = (void *)array + sz; + array = copy_read_group_values(array, read_format, + sample); } else { *array = sample->read.one.id; array++; + + if (read_format & PERF_FORMAT_LOST) { + *array = sample->read.one.lost; + array++; + } } } -- cgit v1.2.3