From nobody Wed Dec 17 10:45:13 2025 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.8]) (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 1E84715B107; Fri, 12 Jul 2024 10:21:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.8 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720779697; cv=none; b=XoCAo339Wkt6lqae5THvDee4gDe7+VeQF76m0YPD0NXwye8hdHlVqofezGdT4R50fEs5kDEQ4ADDt+DWPNvskSna45BA2VSM0Kz8AI41aeUHeRa6usAfhzZEIe80Cg8PNXLadUWnHL1LJpQ4GHAkqmmjfluZxqtKMNx249JW4+M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720779697; c=relaxed/simple; bh=6BwyhI1ygNz4RFIi5YJoddlQb3Ig5C1L4xGiisWXOeM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=keUhovM9R9iTwqWG/Nv14hWO97yYsRxAxnFrvZQc3+QJDBJ4QzPXKGqkrkTL6v4pu/usIWu99b0wORrzfKZvu4VuxsHZ/lHROIxzEtEAxxIcTmw88EcWHfYSnt7Y0wUkuvP4s0BhMtgzk4hxMZKMEVTeMtnEdoGCmd7JUtDxjSk= 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=UQFq3kg+; arc=none smtp.client-ip=192.198.163.8 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="UQFq3kg+" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1720779696; x=1752315696; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=6BwyhI1ygNz4RFIi5YJoddlQb3Ig5C1L4xGiisWXOeM=; b=UQFq3kg+AHrDTWUBQXXW7obJd7YAzIg4CVnv4zW2SnytZAVH0Lkg07iu 6Vze72xvMe9IrdhwyoIDyPMTymFi3HPk7FDE5ku7176iV4EoFkyizN62p NuxkdMaIj98FRKnOc2DFmQJC3VSdI48k9pvPciMThI2chaNmfXuTct2z6 Gav/rg5Qf0l3/MRfsd4wQSg0TVdlmcCLaJtro0ScJSlaFpOt0YBjTPlYF op7N8FM1QOlB67wo36AmLdeAebjMmfS34YPBHPhlduyYRkAIRpG9GvWCk 1zoiM9bt4Y/vnpAazXjfEUDEBkHgPZShCBzDD4zXv8GvUmIJ16DDQefCV w==; X-CSE-ConnectionGUID: TqSU1s5RS3CFytsZiYkqKQ== X-CSE-MsgGUID: H6Obaw8ES+21NtuLWds5Lg== X-IronPort-AV: E=McAfee;i="6700,10204,11130"; a="35756766" X-IronPort-AV: E=Sophos;i="6.09,202,1716274800"; d="scan'208";a="35756766" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by fmvoesa102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jul 2024 03:21:36 -0700 X-CSE-ConnectionGUID: z/Pl6ZbHQZqYAynHkgxdKw== X-CSE-MsgGUID: AqkJ88znShq8914jn9P6VA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.09,202,1716274800"; d="scan'208";a="79576231" Received: from emr.sh.intel.com ([10.112.229.56]) by orviesa002.jf.intel.com with ESMTP; 12 Jul 2024 03:21:32 -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, Yongwei Ma , Dapeng Mi , Dapeng Mi Subject: [Patch v3 2/5] perf x86/topdown: Correct leader selection with sample_read enabled Date: Fri, 12 Jul 2024 17:03:36 +0000 Message-Id: <20240712170339.185824-3-dapeng1.mi@linux.intel.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20240712170339.185824-1-dapeng1.mi@linux.intel.com> References: <20240712170339.185824-1-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 49f25d67ed77..857e00cf579f 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" @@ -87,11 +88,22 @@ bool arch_is_topdown_metrics(const struct evsel *evsel) */ bool arch_topdown_sample_read(struct evsel *leader) { + struct evsel *evsel; + if (!evsel__sys_has_perf_metrics(leader)) return false; =20 - if (arch_is_topdown_slots(leader)) - return true; + if (!arch_is_topdown_slots(leader)) + 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, evsel) { + if (evsel !=3D leader && arch_is_topdown_metrics(evsel)) + return true; + } =20 return false; } --=20 2.40.1