From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932664AbeBPJug (ORCPT ); Fri, 16 Feb 2018 04:50:36 -0500 Received: from terminus.zytor.com ([198.137.202.136]:38015 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932420AbeBPJue (ORCPT ); Fri, 16 Feb 2018 04:50:34 -0500 Date: Fri, 16 Feb 2018 01:40:12 -0800 From: tip-bot for Kan Liang Message-ID: Cc: peterz@infradead.org, namhyung@kernel.org, tglx@linutronix.de, mingo@kernel.org, yao.jin@linux.intel.com, acme@redhat.com, linux-kernel@vger.kernel.org, ak@linux.intel.com, wangnan0@huawei.com, jolsa@kernel.org, kan.liang@intel.com, hpa@zytor.com Reply-To: wangnan0@huawei.com, jolsa@kernel.org, kan.liang@intel.com, hpa@zytor.com, peterz@infradead.org, tglx@linutronix.de, namhyung@kernel.org, mingo@kernel.org, yao.jin@linux.intel.com, acme@redhat.com, linux-kernel@vger.kernel.org, ak@linux.intel.com In-Reply-To: <1516310792-208685-14-git-send-email-kan.liang@intel.com> References: <1516310792-208685-14-git-send-email-kan.liang@intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf top: Add overwrite fall back Git-Commit-ID: 204721d7eabe6ee98aafce791ce3efdbc4715834 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 204721d7eabe6ee98aafce791ce3efdbc4715834 Gitweb: https://git.kernel.org/tip/204721d7eabe6ee98aafce791ce3efdbc4715834 Author: Kan Liang AuthorDate: Thu, 18 Jan 2018 13:26:28 -0800 Committer: Arnaldo Carvalho de Melo CommitDate: Thu, 15 Feb 2018 09:56:14 -0300 perf top: Add overwrite fall back Switch to non-overwrite mode if kernel doesnot support overwrite ringbuffer. It's only effect when overwrite mode is supported. No change to current behavior. Signed-off-by: Kan Liang Acked-by: Jiri Olsa Cc: Andi Kleen Cc: Jin Yao Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1516310792-208685-14-git-send-email-kan.liang@intel.com [ Use perf_missing_features.write_backward instead of the non merged is_write_backward_fail() ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-top.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 1778379..ee4bba1 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -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);