Commit d3944f0e authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
Browse files

perf inject: Lazily allocate event_copy 



The event_copy is 64kb (PERF_SAMPLE_SIZE_MAX) and stack allocated in
struct perf_inject. It is used for aux events that may not exist in a
file. Make the array allocation lazy to cut down on the stack usage.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230527034324.2597593-4-irogers@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent e590e46b

tools/perf/builtin-inject.c

+13 −3
Original line number Diff line number Diff line
@@ -122,7 +122,7 @@ struct perf_inject { 
	u64			aux_id;

	struct list_head	samples;

	struct itrace_synth_opts itrace_synth_opts;

	char			event_copy[PERF_SAMPLE_MAX_SIZE];

	char			*event_copy;

	struct perf_file_section secs[HEADER_FEAT_BITS];

	struct guest_session	guest_session;

	struct strlist		*known_build_ids;
@@ -320,8 +320,14 @@ perf_inject__cut_auxtrace_sample(struct perf_inject *inject, 
{

	size_t sz1 = sample->aux_sample.data - (void *)event;

	size_t sz2 = event->header.size - sample->aux_sample.size - sz1;

	union perf_event *ev = (union perf_event *)inject->event_copy;

	union perf_event *ev;



	if (inject->event_copy == NULL) {

		inject->event_copy = malloc(PERF_SAMPLE_MAX_SIZE);

		if (!inject->event_copy)

			return ERR_PTR(-ENOMEM);

	}

	ev = (union perf_event *)inject->event_copy;

	if (sz1 > event->header.size || sz2 > event->header.size ||

	    sz1 + sz2 > event->header.size ||

	    sz1 < sizeof(struct perf_event_header) + sizeof(u64))
@@ -357,8 +363,11 @@ static int perf_event__repipe_sample(struct perf_tool *tool, 


	build_id__mark_dso_hit(tool, event, sample, evsel, machine);



	if (inject->itrace_synth_opts.set && sample->aux_sample.size)

	if (inject->itrace_synth_opts.set && sample->aux_sample.size) {

		event = perf_inject__cut_auxtrace_sample(inject, event, sample);

		if (IS_ERR(event))

			return PTR_ERR(event);

	}



	return perf_event__repipe_synth(tool, event);

}
@@ -2391,5 +2400,6 @@ int cmd_inject(int argc, const char **argv) 
	if (!inject.in_place_update)

		perf_data__close(&inject.output);

	free(inject.itrace_synth_opts.vm_tm_corr_args);

	free(inject.event_copy);

	return ret;

}