From nobody Fri Dec 19 12:36:15 2025 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.14]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DD2AD12E1C7; Tue, 2 Jul 2024 06:39:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.14 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719902385; cv=none; b=P/EGnt3Dfhj6OJs0FFU/Du9IMda6EwX0xUnexXc/i58+1xroj28MJbeJMcnmQxzabSCyblgKV2Kz5oaQTeXFvSKEC2Ca1paSHMLjvAhVskJkTX4qDOOfPJhpA62nNB3f99wjgRSpbGSpBetv/zbiTWxaJuJUFCq0oH9CiPCFIKM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719902385; c=relaxed/simple; bh=ZClm0i5H0Il54cRWuWGyDTiX2aGbpAZRjtMpNeIqxLM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=pIS2S9TTKzUQnZAMTpDJUM1m39PbnarUg0HZ4kEz7fRY5mzMWMuiw04sPavT3TmpYRWcf+p3+Wi+EwR7QjvwR65DUbVA1e5wG9/kkUMRFtUdB/oeTuvU+xiqT1izs5QtEbH51R+BxnFPeRpMV4w4om1KSHLYKL1xWTvGjpWjyr4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=nfdxGojK; arc=none smtp.client-ip=198.175.65.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="nfdxGojK" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1719902384; x=1751438384; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=ZClm0i5H0Il54cRWuWGyDTiX2aGbpAZRjtMpNeIqxLM=; b=nfdxGojKfXeIh1KziKu5TDLFQxrnS7V59xBMUTn6nXURIW4XgqHqGvjc k3Rp1bptiQK7GkD602FKF8ThoijoOdkgAl+jwZj3r2OwSvgf9qZyEGaQ6 IOxXlFdFV1Tv84NkwhorUcpR+pof6eP+Gif4v6nA27zA1gGPHf8Zsahf5 L+9fDaAc63BXRTgfGnKQ4ixBYjiivN6CmV1G6nRjRX8KIOcsedj1eP2fW ayt6q7Q4LFjChJrSeIaGNtcvR1rCvEMELtubPOD8JyKuJivfQSLkGMbn+ JPgghUzYEeGsGv65T2M8CoeCwwmxnRCxqlHg8vJJTRLHWddjS1yHGtBKJ A==; X-CSE-ConnectionGUID: ArXHdOayS4yz6PpPZpgyCw== X-CSE-MsgGUID: Nshp4690RniwlQqpi3Jnog== X-IronPort-AV: E=McAfee;i="6700,10204,11120"; a="20868287" X-IronPort-AV: E=Sophos;i="6.09,178,1716274800"; d="scan'208";a="20868287" Received: from orviesa009.jf.intel.com ([10.64.159.149]) by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jul 2024 23:39:44 -0700 X-CSE-ConnectionGUID: z09Xz4fLQrymbBuPBA8HpA== X-CSE-MsgGUID: ulAMclR3Saero1o9YjqWXw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.09,178,1716274800"; d="scan'208";a="45926345" Received: from unknown (HELO dell-3650.sh.intel.com) ([10.239.159.147]) by orviesa009.jf.intel.com with ESMTP; 01 Jul 2024 23:39:40 -0700 From: Dapeng Mi To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Ian Rogers , Adrian Hunter , Alexander Shishkin , Kan Liang Cc: linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Yanfei Xu , Dapeng Mi , Dapeng Mi Subject: [PATCH 1/4] perf topdown: Correct leader selection with sample_read enabled Date: Wed, 3 Jul 2024 06:40:34 +0800 Message-Id: <20240702224037.343958-2-dapeng1.mi@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240702224037.343958-1-dapeng1.mi@linux.intel.com> References: <20240702224037.343958-1-dapeng1.mi@linux.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Addresses an issue where, in the absence of a topdown metrics event within a sampling group, the slots event was incorrectly bypassed as the sampling leader when sample_read was enabled. perf record -e '{slots,branches}:S' -c 10000 -vv sleep 1 In this case, the slots event should be sampled as leader but the branches event is sampled in fact like the verbose output shows. perf_event_attr: type 4 (cpu) size 168 config 0x400 (slots) sample_type IP|TID|TIME|READ|CPU|IDENTIFIER read_format ID|GROUP|LOST disabled 1 sample_id_all 1 exclude_guest 1 ------------------------------------------------------------ sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 =3D 5 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) size 168 config 0x4 (PERF_COUNT_HW_BRANCH_INSTRUCTIONS) { sample_period, sample_freq } 10000 sample_type IP|TID|TIME|READ|CPU|IDENTIFIER read_format ID|GROUP|LOST sample_id_all 1 exclude_guest 1 The sample period of slots event instead of branches event is reset to 0. This fix ensures the slots event remains the leader under these conditions. Signed-off-by: Dapeng Mi --- tools/perf/arch/x86/util/topdown.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/tools/perf/arch/x86/util/topdown.c b/tools/perf/arch/x86/util/= topdown.c index 3f9a267d4501..5d7b78eb7516 100644 --- a/tools/perf/arch/x86/util/topdown.c +++ b/tools/perf/arch/x86/util/topdown.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include "api/fs/fs.h" #include "util/evsel.h" +#include "util/evlist.h" #include "util/pmu.h" #include "util/pmus.h" #include "util/topdown.h" @@ -41,11 +42,22 @@ bool topdown_sys_has_perf_metrics(void) */ bool arch_topdown_sample_read(struct evsel *leader) { + struct evsel *event; + if (!evsel__sys_has_perf_metrics(leader)) return false; =20 - if (leader->core.attr.config =3D=3D TOPDOWN_SLOTS) - return true; + if (leader->core.attr.config !=3D TOPDOWN_SLOTS) + return false; + + /* + * If slots event as leader event but no topdown metric events in group, + * slots event should still sample as leader. + */ + evlist__for_each_entry(leader->evlist, event) { + if (event !=3D leader && strcasestr(event->name, "topdown")) + return true; + } =20 return false; } --=20 2.40.1