From nobody Fri Feb 13 04:40:40 2026 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) (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 A53F484039; Mon, 3 Jun 2024 09:33:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.188 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717407231; cv=none; b=nJ38hfbRyYJ9F3XKyRYn11QzGIdgrawL+N5o8tl4WeQ2XY4LHzCvWqJJH412H5tApLpi8cy0ZeMWX4f1zdreWPew1+qwZLXqquB6TTIRpH9AOtVw8XRksDl7K911OkwaWyGRLQ7biOxAjfOxXeaNI16Ocf/ktTX+KVbf8HFy7xU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717407231; c=relaxed/simple; bh=vLeKRnEegxE0K436urLC3fMIxW8y761LOsyI4592Faw=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=pPGNttOTrw/RAXT0Bb6Xaw3TIdaas0+dAsAJM4MzMv4OWU0l6YRDPS1Cb1YFCCdUUu4ElbzXbPj19Zr8ETwauL57iN0YWupxTBBM21PQ3mjozmGNyo9joGUMMZeT4disbQlDNBQJfw9XgRR1261uvlKMNr4XQWC/pDX+wZdGY0o= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.48]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4Vt7hk5M0NzmXXQ; Mon, 3 Jun 2024 17:29:10 +0800 (CST) Received: from kwepemd200014.china.huawei.com (unknown [7.221.188.8]) by mail.maildlp.com (Postfix) with ESMTPS id D03E5180060; Mon, 3 Jun 2024 17:33:40 +0800 (CST) Received: from localhost.localdomain (10.50.165.33) by kwepemd200014.china.huawei.com (7.221.188.8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Mon, 3 Jun 2024 17:33:40 +0800 From: Yicong Yang To: , , , , , , CC: , , , , , , , , , , Subject: [PATCH 1/3] perf pmu: Limit PMU cpumask to online CPUs Date: Mon, 3 Jun 2024 17:28:10 +0800 Message-ID: <20240603092812.46616-2-yangyicong@huawei.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20240603092812.46616-1-yangyicong@huawei.com> References: <20240603092812.46616-1-yangyicong@huawei.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 X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemd200014.china.huawei.com (7.221.188.8) Content-Type: text/plain; charset="utf-8" From: Yicong Yang We'll initialize the PMU's cpumask from "cpumask" or "cpus" sysfs attributes if provided by the driver without checking the CPUs are online or not. In such case that CPUs provided by the driver contains the offline CPUs, we'll try to open event on the offline CPUs and then rejected by the kernel: [root@localhost yang]# echo 0 > /sys/devices/system/cpu/cpu0/online [root@localhost yang]# ./perf_static stat -e armv8_pmuv3_0/cycles/ --timeou= t 100 Error: The sys_perf_event_open() syscall returned with 19 (No such device) for eve= nt (cpu-clock). /bin/dmesg | grep -i perf may provide additional information. So it's better to do a double check in the userspace and only include the online CPUs from "cpumask" or "cpus" to avoid opening events on offline CPUs. Signed-off-by: Yicong Yang --- tools/perf/util/pmu.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index 888ce9912275..51e8d10ee28b 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -771,8 +771,17 @@ static struct perf_cpu_map *pmu_cpumask(int dirfd, con= st char *name, bool is_cor continue; cpus =3D perf_cpu_map__read(file); fclose(file); - if (cpus) - return cpus; + if (cpus) { + struct perf_cpu_map *intersect __maybe_unused; + + if (perf_cpu_map__is_subset(cpu_map__online(), cpus)) + return cpus; + + intersect =3D perf_cpu_map__intersect(cpus, cpu_map__online()); + perf_cpu_map__put(cpus); + if (intersect) + return intersect; + } } =20 /* Nothing found, for core PMUs assume this means all CPUs. */ --=20 2.24.0