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perf record: Read and inject LOST_SAMPLES events

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When there are lost samples, it can read the number of PERF_FORMAT_LOST and
convert it to PERF_RECORD_LOST_SAMPLES and write to the data file at the end.

Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220901195739.668604-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim 2022-09-01 12:57:37 -07:00 committed by Arnaldo Carvalho de Melo
parent e17f343c3b
commit e3a23261ad
1 changed files with 64 additions and 0 deletions
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64
tools/perf/builtin-record.c
View file

@ -10,6 +10,7 @@
#include "util/build-id.h"
#include <subcmd/parse-options.h>
#include <internal/xyarray.h>
#include "util/parse-events.h"
#include "util/config.h"
@ -1852,6 +1853,68 @@ record__switch_output(struct record *rec, bool at_exit)
return fd;
}
static void __record__read_lost_samples(struct record *rec, struct evsel *evsel,
struct perf_record_lost_samples *lost,
int cpu_idx, int thread_idx)
{
struct perf_counts_values count;
struct perf_sample_id *sid;
struct perf_sample sample = {};
int id_hdr_size;
if (perf_evsel__read(&evsel->core, cpu_idx, thread_idx, &count) < 0) {
pr_err("read LOST count failed\n");
return;
}
if (count.lost == 0)
return;
lost->lost = count.lost;
if (evsel->core.ids) {
sid = xyarray__entry(evsel->core.sample_id, cpu_idx, thread_idx);
sample.id = sid->id;
}
id_hdr_size = perf_event__synthesize_id_sample((void *)(lost + 1),
evsel->core.attr.sample_type, &sample);
lost->header.size = sizeof(*lost) + id_hdr_size;
record__write(rec, NULL, lost, lost->header.size);
}
static void record__read_lost_samples(struct record *rec)
{
struct perf_session *session = rec->session;
struct perf_record_lost_samples *lost;
struct evsel *evsel;
lost = zalloc(PERF_SAMPLE_MAX_SIZE);
if (lost == NULL) {
pr_debug("Memory allocation failed\n");
return;
}
lost->header.type = PERF_RECORD_LOST_SAMPLES;
evlist__for_each_entry(session->evlist, evsel) {
struct xyarray *xy = evsel->core.sample_id;
if (xyarray__max_x(evsel->core.fd) != xyarray__max_x(xy) ||
xyarray__max_y(evsel->core.fd) != xyarray__max_y(xy)) {
pr_debug("Unmatched FD vs. sample ID: skip reading LOST count\n");
continue;
}
for (int x = 0; x < xyarray__max_x(xy); x++) {
for (int y = 0; y < xyarray__max_y(xy); y++) {
__record__read_lost_samples(rec, evsel, lost, x, y);
}
}
}
free(lost);
}
static volatile int workload_exec_errno;
/*
@ -2714,6 +2777,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
if (rec->off_cpu)
rec->bytes_written += off_cpu_write(rec->session);
record__read_lost_samples(rec);
record__synthesize(rec, true);
/* this will be recalculated during process_buildids() */
rec->samples = 0;