[PATCH 34/39] perf inject: Add --strip option to strip out non-synthesized events

From: Arnaldo Carvalho de Melo
Date: Mon Sep 28 2015 - 17:13:59 EST


From: Adrian Hunter <adrian.hunter@xxxxxxxxx>

Add a new option --strip which is used with --itrace to strip out
non-synthesized events. This results in a perf.data file that is
simpler for external tools to parse. In particular, this can be used to
prepare a perf.data file for consumption by autofdo.

A subsequent patch makes a change to Intel PT also to enable use with
autofdo and gives an example of that use.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1443186956-18718-25-git-send-email-adrian.hunter@xxxxxxxxx
[ Made it use perf_evlist__remove() + perf_evsel__delete() ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Documentation/perf-inject.txt | 3 ++
tools/perf/builtin-inject.c | 92 ++++++++++++++++++++++++++++++++
2 files changed, 95 insertions(+)

diff --git a/tools/perf/Documentation/perf-inject.txt b/tools/perf/Documentation/perf-inject.txt
index 0c721c3e37e1..0b1cedeef895 100644
--- a/tools/perf/Documentation/perf-inject.txt
+++ b/tools/perf/Documentation/perf-inject.txt
@@ -50,6 +50,9 @@ OPTIONS

include::itrace.txt[]

+--strip::
+ Use with --itrace to strip out non-synthesized events.
+
SEE ALSO
--------
linkperf:perf-record[1], linkperf:perf-report[1], linkperf:perf-archive[1]
diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index 9b6119f134b4..0a945d2e8ca5 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -28,6 +28,7 @@ struct perf_inject {
bool build_ids;
bool sched_stat;
bool have_auxtrace;
+ bool strip;
const char *input_name;
struct perf_data_file output;
u64 bytes_written;
@@ -177,6 +178,14 @@ static int perf_event__repipe(struct perf_tool *tool,
return perf_event__repipe_synth(tool, event);
}

+static int perf_event__drop(struct perf_tool *tool __maybe_unused,
+ union perf_event *event __maybe_unused,
+ struct perf_sample *sample __maybe_unused,
+ struct machine *machine __maybe_unused)
+{
+ return 0;
+}
+
static int perf_event__drop_aux(struct perf_tool *tool,
union perf_event *event __maybe_unused,
struct perf_sample *sample,
@@ -480,6 +489,78 @@ static int perf_evsel__check_stype(struct perf_evsel *evsel,
return 0;
}

+static int drop_sample(struct perf_tool *tool __maybe_unused,
+ union perf_event *event __maybe_unused,
+ struct perf_sample *sample __maybe_unused,
+ struct perf_evsel *evsel __maybe_unused,
+ struct machine *machine __maybe_unused)
+{
+ return 0;
+}
+
+static void strip_init(struct perf_inject *inject)
+{
+ struct perf_evlist *evlist = inject->session->evlist;
+ struct perf_evsel *evsel;
+
+ inject->tool.context_switch = perf_event__drop;
+
+ evlist__for_each(evlist, evsel)
+ evsel->handler = drop_sample;
+}
+
+static bool has_tracking(struct perf_evsel *evsel)
+{
+ return evsel->attr.mmap || evsel->attr.mmap2 || evsel->attr.comm ||
+ evsel->attr.task;
+}
+
+#define COMPAT_MASK (PERF_SAMPLE_ID | PERF_SAMPLE_TID | PERF_SAMPLE_TIME | \
+ PERF_SAMPLE_ID | PERF_SAMPLE_CPU | PERF_SAMPLE_IDENTIFIER)
+
+/*
+ * In order that the perf.data file is parsable, tracking events like MMAP need
+ * their selected event to exist, except if there is only 1 selected event left
+ * and it has a compatible sample type.
+ */
+static bool ok_to_remove(struct perf_evlist *evlist,
+ struct perf_evsel *evsel_to_remove)
+{
+ struct perf_evsel *evsel;
+ int cnt = 0;
+ bool ok = false;
+
+ if (!has_tracking(evsel_to_remove))
+ return true;
+
+ evlist__for_each(evlist, evsel) {
+ if (evsel->handler != drop_sample) {
+ cnt += 1;
+ if ((evsel->attr.sample_type & COMPAT_MASK) ==
+ (evsel_to_remove->attr.sample_type & COMPAT_MASK))
+ ok = true;
+ }
+ }
+
+ return ok && cnt == 1;
+}
+
+static void strip_fini(struct perf_inject *inject)
+{
+ struct perf_evlist *evlist = inject->session->evlist;
+ struct perf_evsel *evsel, *tmp;
+
+ /* Remove non-synthesized evsels if possible */
+ evlist__for_each_safe(evlist, tmp, evsel) {
+ if (evsel->handler == drop_sample &&
+ ok_to_remove(evlist, evsel)) {
+ pr_debug("Deleting %s\n", perf_evsel__name(evsel));
+ perf_evlist__remove(evlist, evsel);
+ perf_evsel__delete(evsel);
+ }
+ }
+}
+
static int __cmd_inject(struct perf_inject *inject)
{
int ret = -EINVAL;
@@ -532,6 +613,8 @@ static int __cmd_inject(struct perf_inject *inject)
inject->tool.ordering_requires_timestamps = true;
/* Allow space in the header for new attributes */
output_data_offset = 4096;
+ if (inject->strip)
+ strip_init(inject);
}

if (!inject->itrace_synth_opts.set)
@@ -570,6 +653,8 @@ static int __cmd_inject(struct perf_inject *inject)
perf_evlist__remove(session->evlist, evsel);
perf_evsel__delete(evsel);
}
+ if (inject->strip)
+ strip_fini(inject);
}
session->header.data_offset = output_data_offset;
session->header.data_size = inject->bytes_written;
@@ -635,6 +720,8 @@ int cmd_inject(int argc, const char **argv, const char *prefix __maybe_unused)
OPT_CALLBACK_OPTARG(0, "itrace", &inject.itrace_synth_opts,
NULL, "opts", "Instruction Tracing options",
itrace_parse_synth_opts),
+ OPT_BOOLEAN(0, "strip", &inject.strip,
+ "strip non-synthesized events (use with --itrace)"),
OPT_END()
};
const char * const inject_usage[] = {
@@ -650,6 +737,11 @@ int cmd_inject(int argc, const char **argv, const char *prefix __maybe_unused)
if (argc)
usage_with_options(inject_usage, options);

+ if (inject.strip && !inject.itrace_synth_opts.set) {
+ pr_err("--strip option requires --itrace option\n");
+ return -1;
+ }
+
if (perf_data_file__open(&inject.output)) {
perror("failed to create output file");
return -1;
--
2.1.0

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