Commit fd643afc authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
Browse files

perf record: Save DSO build-ID for synthesizing 



When synthesizing MMAP2 with build-id, it'd read the same file repeatedly as
it has no idea if it's done already.  Maintain a dsos to check that and skip
the file access if possible.

Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
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/20220920222822.2171056-2-namhyung@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent fa2edc07

tools/perf/util/synthetic-events.c

+22 −3
Original line number Diff line number Diff line
@@ -364,11 +364,14 @@ static bool read_proc_maps_line(struct io *io, __u64 *start, __u64 *end, 
}



static void perf_record_mmap2__read_build_id(struct perf_record_mmap2 *event,

					     struct machine *machine,

					     bool is_kernel)

{

	struct build_id bid;

	struct nsinfo *nsi;

	struct nscookie nc;

	struct dso *dso = NULL;

	struct dso_id id;

	int rc;



	if (is_kernel) {
@@ -376,6 +379,18 @@ static void perf_record_mmap2__read_build_id(struct perf_record_mmap2 *event, 
		goto out;

	}



	id.maj = event->maj;

	id.min = event->min;

	id.ino = event->ino;

	id.ino_generation = event->ino_generation;



	dso = dsos__findnew_id(&machine->dsos, event->filename, &id);

	if (dso && dso->has_build_id) {

		bid = dso->bid;

		rc = 0;

		goto out;

	}



	nsi = nsinfo__new(event->pid);

	nsinfo__mountns_enter(nsi, &nc);
@@ -391,12 +406,16 @@ static void perf_record_mmap2__read_build_id(struct perf_record_mmap2 *event, 
		event->header.misc |= PERF_RECORD_MISC_MMAP_BUILD_ID;

		event->__reserved_1 = 0;

		event->__reserved_2 = 0;



		if (dso && !dso->has_build_id)

			dso__set_build_id(dso, &bid);

	} else {

		if (event->filename[0] == '/') {

			pr_debug2("Failed to read build ID for %s\n",

				  event->filename);

		}

	}

	dso__put(dso);

}



int perf_event__synthesize_mmap_events(struct perf_tool *tool,
@@ -507,7 +526,7 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool, 
		event->mmap2.tid = pid;



		if (symbol_conf.buildid_mmap2)

			perf_record_mmap2__read_build_id(&event->mmap2, false);

			perf_record_mmap2__read_build_id(&event->mmap2, machine, false);



		if (perf_tool__process_synth_event(tool, event, machine, process) != 0) {

			rc = -1;
@@ -690,7 +709,7 @@ int perf_event__synthesize_modules(struct perf_tool *tool, perf_event__handler_t 
			memcpy(event->mmap2.filename, pos->dso->long_name,

			       pos->dso->long_name_len + 1);



			perf_record_mmap2__read_build_id(&event->mmap2, false);

			perf_record_mmap2__read_build_id(&event->mmap2, machine, false);

		} else {

			size = PERF_ALIGN(pos->dso->long_name_len + 1, sizeof(u64));

			event->mmap.header.type = PERF_RECORD_MMAP;
@@ -1126,7 +1145,7 @@ static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool, 
		event->mmap2.len   = map->end - event->mmap.start;

		event->mmap2.pid   = machine->pid;



		perf_record_mmap2__read_build_id(&event->mmap2, true);

		perf_record_mmap2__read_build_id(&event->mmap2, machine, true);

	} else {

		size = snprintf(event->mmap.filename, sizeof(event->mmap.filename),

				"%s%s", machine->mmap_name, kmap->ref_reloc_sym->name) + 1;