From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D8D9C47253 for ; Fri, 1 May 2020 10:23:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 441E3206B8 for ; Fri, 1 May 2020 10:23:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="aYrUs1iT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728585AbgEAKXu (ORCPT ); Fri, 1 May 2020 06:23:50 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:32585 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728229AbgEAKXt (ORCPT ); Fri, 1 May 2020 06:23:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1588328628; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=byxFlKeuowY0yc0XBoCAz1C2pz8gQc7fx1kR9pv0BaE=; b=aYrUs1iTCJo4lBsYPa08wa3Ba1cjvW3F/ao/oqupTMszljmLHM2Pb/K8laY5oj1brwS+n5 M796zJMV1e/Sdmq3MTn1utSL4ZxE0noUkktIVfEuo/aAGc/gMYGgXHhlM7oeLeAYjT3CkQ hJ2R4cm9uoCNFhlLSVY9RMBw5t87z18= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-35-7TQAXia3Oi295juXPFoMqQ-1; Fri, 01 May 2020 06:23:44 -0400 X-MC-Unique: 7TQAXia3Oi295juXPFoMqQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6284C80183C; Fri, 1 May 2020 10:23:42 +0000 (UTC) Received: from krava (unknown [10.40.192.9]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 33AAD5C1B0; Fri, 1 May 2020 10:23:40 +0000 (UTC) Date: Fri, 1 May 2020 12:23:37 +0200 From: Jiri Olsa To: Jin Yao Cc: acme@kernel.org, jolsa@kernel.org, peterz@infradead.org, mingo@redhat.com, alexander.shishkin@linux.intel.com, Linux-kernel@vger.kernel.org, ak@linux.intel.com, kan.liang@intel.com, yao.jin@intel.com Subject: Re: [PATCH] perf evsel: Get group fd from CPU0 for system wide event Message-ID: <20200501102337.GA1761222@krava> References: <20200430013451.17196-1-yao.jin@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200430013451.17196-1-yao.jin@linux.intel.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 30, 2020 at 09:34:51AM +0800, Jin Yao wrote: > A metric may consist of system wide event and non system-wide event. > The event group leader may be the system wide event. > > For example, the metric "C2_Pkg_Residency" consists of > "cstate_pkg/c2-residency" and "msr/tsc". The former counts on the first > CPU of socket (tagged system-wide) and the latter is per CPU. > > But "C2_Pkg_Residency" hits assertion failure on cascadelakex. > > # perf stat -M "C2_Pkg_Residency" -a -- sleep 1 > perf: util/evsel.c:1464: get_group_fd: Assertion `!(fd == -1)' failed. > Aborted > > get_group_fd(evsel, cpu, thread) > { > leader = evsel->leader; > fd = FD(leader, cpu, thread); > BUG_ON(fd == -1); > } > > Considering this case, leader is "cstate_pkg/c2-residency", evsel is > "msr/tsc" and cpu is 1. Because "cstate_pkg/c2-residency" is a system-wide > event and it's processed on CPU0, so FD(leader, 1, thread) must return an > invalid fd, then BUG_ON() may be triggered. > > This patch gets group fd from CPU0 for system wide event if > FD(leader, cpu, thread) returns invalid fd. > > With this patch, > > # perf stat -M "C2_Pkg_Residency" -a -- sleep 1 > > Performance counter stats for 'system wide': > > 1000850802 cstate_pkg/c2-residency/ # 0.5 C2_Pkg_Residency > 201446161592 msr/tsc/ > > 1.010637051 seconds time elapsed > > Fixes: 6a4bb04caacc ("perf tools: Enable grouping logic for parsed events") > Signed-off-by: Jin Yao > --- > tools/perf/util/evsel.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c > index 6a571d322bb2..cd6470f63d6f 100644 > --- a/tools/perf/util/evsel.c > +++ b/tools/perf/util/evsel.c > @@ -1461,6 +1461,9 @@ static int get_group_fd(struct evsel *evsel, int cpu, int thread) > BUG_ON(!leader->core.fd); > > fd = FD(leader, cpu, thread); > + if (fd == -1 && leader->core.system_wide) fd does not need to be -1 in here.. in my setup cstate_pkg/c2-residency/ has cpumask 0, so other cpus never get open and are 0, and the whole thing ends up with: sys_perf_event_open: pid -1 cpu 1 group_fd 0 flags 0 sys_perf_event_open failed, error -9 I actualy thought we put -1 to fd array but couldn't find it.. perhaps we should od that > + fd = FD(leader, 0, thread); > + so how do we group following events? cstate_pkg/c2-residency/ - cpumask 0 msr/tsc/ - all cpus cpu 0 is fine.. the rest I have no idea ;-) that's why metrics use the :W, that disables grouping on failure jirka > BUG_ON(fd == -1); > > return fd; > -- > 2.17.1 >