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Commit 63878a53 authored by Kan Liang's avatar Kan Liang Committed by Arnaldo Carvalho de Melo
Browse files

perf top: Check per-event overwrite term 



Per-event overwrite term is not forbidden in 'perf top', which can bring
problems. Because 'perf top' only support non-overwrite mode now.

Add new rules and check regarding to overwrite term for 'perf top'.
- All events either have same per-event term or don't have per-event
  mode setting. Otherwise, it will error out.
- Per-event overwrite term should be consistent as opts->overwrite.
  If not, updating the opts->overwrite according to per-event term.

Make it possible to support either non-overwrite or overwrite mode.
The overwrite mode is forbidden now, which will be removed when the
overwrite mode is supported later.

Signed-off-by: default avatarKan Liang <kan.liang@intel.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1516310792-208685-12-git-send-email-kan.liang@intel.com


[ Renamed perf_top_overwrite_check to perf_top__overwrite_check, to follow existing convention ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 3effc2f1

tools/perf/builtin-top.c

+73 −0
Original line number Diff line number Diff line
@@ -881,6 +881,68 @@ static void perf_top__mmap_read(struct perf_top *top) 
		perf_top__mmap_read_idx(top, i);

}



/*

 * Check per-event overwrite term.

 * perf top should support consistent term for all events.

 * - All events don't have per-event term

 *   E.g. "cpu/cpu-cycles/,cpu/instructions/"

 *   Nothing change, return 0.

 * - All events have same per-event term

 *   E.g. "cpu/cpu-cycles,no-overwrite/,cpu/instructions,no-overwrite/

 *   Using the per-event setting to replace the opts->overwrite if

 *   they are different, then return 0.

 * - Events have different per-event term

 *   E.g. "cpu/cpu-cycles,overwrite/,cpu/instructions,no-overwrite/"

 *   Return -1

 * - Some of the event set per-event term, but some not.

 *   E.g. "cpu/cpu-cycles/,cpu/instructions,no-overwrite/"

 *   Return -1

 */

static int perf_top__overwrite_check(struct perf_top *top)

{

	struct record_opts *opts = &top->record_opts;

	struct perf_evlist *evlist = top->evlist;

	struct perf_evsel_config_term *term;

	struct list_head *config_terms;

	struct perf_evsel *evsel;

	int set, overwrite = -1;



	evlist__for_each_entry(evlist, evsel) {

		set = -1;

		config_terms = &evsel->config_terms;

		list_for_each_entry(term, config_terms, list) {

			if (term->type == PERF_EVSEL__CONFIG_TERM_OVERWRITE)

				set = term->val.overwrite ? 1 : 0;

		}



		/* no term for current and previous event (likely) */

		if ((overwrite < 0) && (set < 0))

			continue;



		/* has term for both current and previous event, compare */

		if ((overwrite >= 0) && (set >= 0) && (overwrite != set))

			return -1;



		/* no term for current event but has term for previous one */

		if ((overwrite >= 0) && (set < 0))

			return -1;



		/* has term for current event */

		if ((overwrite < 0) && (set >= 0)) {

			/* if it's first event, set overwrite */

			if (evsel == perf_evlist__first(evlist))

				overwrite = set;

			else

				return -1;

		}

	}



	if ((overwrite >= 0) && (opts->overwrite != overwrite))

		opts->overwrite = overwrite;



	return 0;

}



static int perf_top__start_counters(struct perf_top *top)

{

	char msg[BUFSIZ];
@@ -888,6 +950,17 @@ static int perf_top__start_counters(struct perf_top *top) 
	struct perf_evlist *evlist = top->evlist;

	struct record_opts *opts = &top->record_opts;



	if (perf_top__overwrite_check(top)) {

		ui__error("perf top only support consistent per-event "

			  "overwrite setting for all events\n");

		goto out_err;

	}



	if (opts->overwrite) {

		ui__error("not support overwrite mode yet\n");

		goto out_err;

	}



	perf_evlist__config(evlist, opts, &callchain_param);



	evlist__for_each_entry(evlist, counter) {