From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751319AbbE1EOR (ORCPT ); Thu, 28 May 2015 00:14:17 -0400 Received: from mga02.intel.com ([134.134.136.20]:13905 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752306AbbE1ENZ (ORCPT ); Thu, 28 May 2015 00:13:25 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.13,510,1427785200"; d="scan'208";a="732880459" From: Andi Kleen To: peterz@infradead.org Cc: acme@kernel.org, linux-kernel@vger.kernel.org, jolsa@redhat.com, eranian@google.com, Andi Kleen Subject: [PATCH 3/5] perf, tools: Disable branch flags/cycles for lbr call graph Date: Wed, 27 May 2015 21:13:16 -0700 Message-Id: <1432786398-23861-4-git-send-email-andi@firstfloor.org> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1432786398-23861-1-git-send-email-andi@firstfloor.org> References: <1432786398-23861-1-git-send-email-andi@firstfloor.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andi Kleen Automatically disable collecting branch flags and cycles with --call-graph lbr. This allows avoiding a bunch of extra MSR reads in the PMI on Skylake. When the kernel doesn't support the new flags they are automatically cleared in the fallback code. Signed-off-by: Andi Kleen --- tools/perf/util/evsel.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index c886b9f..4d8a86c 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -557,6 +557,8 @@ perf_evsel__config_callgraph(struct perf_evsel *evsel, "Falling back to framepointers.\n"); } else { perf_evsel__set_sample_bit(evsel, BRANCH_STACK); + perf_evsel__set_sample_bit(evsel, BRANCH_NO_CYCLES); + perf_evsel__set_sample_bit(evsel, BRANCH_NO_FLAGS); attr->branch_sample_type = PERF_SAMPLE_BRANCH_USER | PERF_SAMPLE_BRANCH_CALL_STACK; } @@ -1167,6 +1169,8 @@ fallback_missing_features: evsel->attr.mmap2 = 0; if (perf_missing_features.exclude_guest) evsel->attr.exclude_guest = evsel->attr.exclude_host = 0; + evsel->attr.sample_type &= ~(PERF_SAMPLE_BRANCH_NO_FLAGS| + PERF_SAMPLE_BRANCH_NO_CYCLES); retry_sample_id: if (perf_missing_features.sample_id_all) evsel->attr.sample_id_all = 0; -- 2.1.0