Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752116AbaBGBfz (ORCPT ); Thu, 6 Feb 2014 20:35:55 -0500 Received: from lgeamrelo01.lge.com ([156.147.1.125]:63761 "EHLO LGEAMRELO01.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751446AbaBGBfn (ORCPT ); Thu, 6 Feb 2014 20:35:43 -0500 X-AuditID: 9c93017d-b7b1fae00000636d-b0-52f4386d26d5 From: Namhyung Kim To: Arnaldo Carvalho de Melo Cc: Peter Zijlstra , Ingo Molnar , Paul Mackerras , Namhyung Kim , LKML , Arun Sharma , Frederic Weisbecker , Rodrigo Campos , Andi Kleen , David Ahern Subject: [PATCH 06/21] perf report: Cache cumulative callchains Date: Fri, 7 Feb 2014 10:35:08 +0900 Message-Id: <1391736923-30765-7-git-send-email-namhyung@kernel.org> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <1391736923-30765-1-git-send-email-namhyung@kernel.org> References: <1391736923-30765-1-git-send-email-namhyung@kernel.org> X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It is possble that a callchain has cycles or recursive calls. In that case it'll end up having entries more than 100% overhead in the output. In order to prevent such entries, cache each callchain node and skip if same entry already cumulated. Tested-by: Arun Sharma Cc: Frederic Weisbecker Signed-off-by: Namhyung Kim --- tools/perf/util/hist.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c index 15e619d6654f..7529d216986a 100644 --- a/tools/perf/util/hist.c +++ b/tools/perf/util/hist.c @@ -709,7 +709,22 @@ static int iter_prepare_cumulative_entry(struct hist_entry_iter *iter __maybe_unused, struct addr_location *al __maybe_unused) { + struct hist_entry **he_cache; + callchain_cursor_commit(&callchain_cursor); + + /* + * This is for detecting cycles or recursions so that they're + * cumulated only one time to prevent entries more than 100% + * overhead. + */ + he_cache = malloc(sizeof(*he_cache) * (PERF_MAX_STACK_DEPTH + 1)); + if (he_cache == NULL) + return -ENOMEM; + + iter->priv = he_cache; + iter->curr = 0; + return 0; } @@ -719,6 +734,7 @@ iter_add_single_cumulative_entry(struct hist_entry_iter *iter, { struct perf_evsel *evsel = iter->evsel; struct perf_sample *sample = iter->sample; + struct hist_entry **he_cache = iter->priv; struct hist_entry *he; he = __hists__add_entry(&evsel->hists, al, iter->parent, NULL, NULL, @@ -727,6 +743,8 @@ iter_add_single_cumulative_entry(struct hist_entry_iter *iter, if (he == NULL) return -ENOMEM; + he_cache[iter->curr++] = he; + return hist_entry__inc_addr_samples(he, evsel->idx, al->addr); } @@ -751,7 +769,29 @@ iter_add_next_cumulative_entry(struct hist_entry_iter *iter, { struct perf_evsel *evsel = iter->evsel; struct perf_sample *sample = iter->sample; + struct hist_entry **he_cache = iter->priv; struct hist_entry *he; + struct hist_entry he_tmp = { + .cpu = al->cpu, + .thread = al->thread, + .comm = thread__comm(al->thread), + .ip = al->addr, + .ms = { + .map = al->map, + .sym = al->sym, + }, + .parent = iter->parent, + }; + int i; + + /* + * Check if there's duplicate entries in the callchain. + * It's possible that it has cycles or recursive calls. + */ + for (i = 0; i < iter->curr; i++) { + if (hist_entry__cmp(he_cache[i], &he_tmp) == 0) + return 0; + } he = __hists__add_entry(&evsel->hists, al, iter->parent, NULL, NULL, sample->period, sample->weight, @@ -759,6 +799,8 @@ iter_add_next_cumulative_entry(struct hist_entry_iter *iter, if (he == NULL) return -ENOMEM; + he_cache[iter->curr++] = he; + return hist_entry__inc_addr_samples(he, evsel->idx, al->addr); } @@ -772,6 +814,7 @@ iter_finish_cumulative_entry(struct hist_entry_iter *iter, evsel->hists.stats.total_period += sample->period; hists__inc_nr_events(&evsel->hists, PERF_RECORD_SAMPLE); + zfree(&iter->priv); return 0; } -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/