perf top: Add overwrite fall back (204721d7) · Commits · 戴 / test

tools/perf/builtin-top.c

+36 −0

Original line number	Diff line number	Diff line
		@@ -943,6 +943,27 @@ static int perf_top__overwrite_check(struct perf_top *top)
		return 0;
		}

		static int perf_top_overwrite_fallback(struct perf_top *top,
		struct perf_evsel *evsel)
		{
		struct record_opts *opts = &top->record_opts;
		struct perf_evlist *evlist = top->evlist;
		struct perf_evsel *counter;

		if (!opts->overwrite)
		return 0;

		/* only fall back when first event fails */
		if (evsel != perf_evlist__first(evlist))
		return 0;

		evlist__for_each_entry(evlist, counter)
		counter->attr.write_backward = false;
		opts->overwrite = false;
		ui__warning("fall back to non-overwrite mode\n");
		return 1;
		}

		static int perf_top__start_counters(struct perf_top *top)
		{
		char msg[BUFSIZ];
		@@ -967,6 +988,21 @@ static int perf_top__start_counters(struct perf_top *top)
		try_again:
		if (perf_evsel__open(counter, top->evlist->cpus,
		top->evlist->threads) < 0) {

		/*
		* Specially handle overwrite fall back.
		* Because perf top is the only tool which has
		* overwrite mode by default, support
		* both overwrite and non-overwrite mode, and
		* require consistent mode for all events.
		*
		* May move it to generic code with more tools
		* have similar attribute.
		*/
		if (perf_missing_features.write_backward &&
		perf_top_overwrite_fallback(top, counter))
		goto try_again;

		if (perf_evsel__fallback(counter, errno, msg, sizeof(msg))) {
		if (verbose > 0)
		ui__warning("%s\n", msg);