Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932080AbbLNRor (ORCPT ); Mon, 14 Dec 2015 12:44:47 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:33460 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751901AbbLNRoq (ORCPT ); Mon, 14 Dec 2015 12:44:46 -0500 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Andi Kleen , Arnaldo Carvalho de Melo Subject: [PATCH 04/16] perf evsel: Disable branch flags/cycles for --callgraph lbr Date: Mon, 14 Dec 2015 14:44:29 -0300 Message-Id: <1450115081-22962-5-git-send-email-acme@kernel.org> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1450115081-22962-1-git-send-email-acme@kernel.org> References: <1450115081-22962-1-git-send-email-acme@kernel.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2747 Lines: 79 From: Andi Kleen [The kernel patch needed for this is in tip now (b16a5b52eb9 perf/x86: Add option to disable ...) So this user tools patch to make use of it should be merged now] 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. v2: Switch to use branch_sample_type instead of sample_type. Adjust description. Fix the fallback logic. Signed-off-by: Andi Kleen Acked-by: Jiri Olsa Link: http://lkml.kernel.org/r/1449879144-29074-1-git-send-email-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/evsel.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 47f033089349..544e4400de13 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -36,6 +36,7 @@ static struct { bool cloexec; bool clockid; bool clockid_wrong; + bool lbr_flags; } perf_missing_features; static clockid_t clockid; @@ -574,7 +575,9 @@ perf_evsel__config_callgraph(struct perf_evsel *evsel, } else { perf_evsel__set_sample_bit(evsel, BRANCH_STACK); attr->branch_sample_type = PERF_SAMPLE_BRANCH_USER | - PERF_SAMPLE_BRANCH_CALL_STACK; + PERF_SAMPLE_BRANCH_CALL_STACK | + PERF_SAMPLE_BRANCH_NO_CYCLES | + PERF_SAMPLE_BRANCH_NO_FLAGS; } } else pr_warning("Cannot use LBR callstack with branch stack. " @@ -1337,6 +1340,9 @@ fallback_missing_features: evsel->attr.mmap2 = 0; if (perf_missing_features.exclude_guest) evsel->attr.exclude_guest = evsel->attr.exclude_host = 0; + if (perf_missing_features.lbr_flags) + evsel->attr.branch_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; @@ -1455,6 +1461,12 @@ try_fallback: } else if (!perf_missing_features.sample_id_all) { perf_missing_features.sample_id_all = true; goto retry_sample_id; + } else if (!perf_missing_features.lbr_flags && + (evsel->attr.branch_sample_type & + (PERF_SAMPLE_BRANCH_NO_CYCLES | + PERF_SAMPLE_BRANCH_NO_FLAGS))) { + perf_missing_features.lbr_flags = true; + goto fallback_missing_features; } out_close: -- 2.1.0 -- 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/