From patchwork Wed Apr 3 15:59:44 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dawei Li X-Patchwork-Id: 13616427 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4DC97CD1288 for ; Wed, 3 Apr 2024 16:02:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=yvQdV5E/DW+16EtY6MWxHDLHUcZabP01PoNnZFC27P0=; b=36mM6TcCZ7XfhI BX1WZhLuNDlqtDkKXy9q8djwBc/tTglvBmTUGE8pPU1BhCb5y2x3QKEyeoKTskT8mAPHUPbwNz8mW /so+KRSqo187Jea29H8wzl9u+OqTBudAvVYES8b0SXdrN6Az5MQqgroBBuT3pGyQoXojc2xYkCoL3 P8T45pnKu5H4h2vd6gBUzT1UpRB8912rnqtre75NDx5gV941qg/DFaWm3Asz3d39nPTUHpM+p/sJn HryCFDz2GBZcgx6hHEghh/TPqOCEr5tBqHVytLu9IVIOCww9Mcn5JzsFlG6PylD/lFRgALTN8KLml GeobmNRClLhwhivYlfMA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rs33y-0000000Gs5q-0wUt; Wed, 03 Apr 2024 16:02:10 +0000 Received: from smtpbguseast1.qq.com ([54.204.34.129]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rs33r-0000000Grti-12wE for linux-arm-kernel@lists.infradead.org; Wed, 03 Apr 2024 16:02:09 +0000 X-QQ-mid: bizesmtp80t1712160051t70qzemv X-QQ-Originating-IP: Oo4ukKkdjd17r5jhqu8+60Tput81uspxOdY3X3VlDnY= Received: from localhost ( [112.0.147.175]) by bizesmtp.qq.com (ESMTP) with id ; Thu, 04 Apr 2024 00:00:50 +0800 (CST) X-QQ-SSF: 01400000000000704000000A0000000 X-QQ-FEAT: FS9dDLprKnLjfIfqSlSBb3P/B9xD0O4QGjyRvlcJsMwQ4F5ZjMgb9BpsLWDCJ C7H+C8HevGdtR71kImRZ7zPfl58ezrpV6zpqs9sAenuqtG+DVLYppJFgk0Mcpa1/Y629W5Z 9h5B5Hj5hF/hnxNaJ/VUqeWKWKwk/7zOc6G9KRQ5JFluEgcu3t2mxf+sNPzkTOdtNczbn/D /zte8mBNMTQe24hPD2fgysSufvF+kpad8OjGYLojRbXMhFOGpJYetnqdOvn4X+Hz9fGhuQP TLJg6w24feAryXzE9y/CMRZmPuJd8u96wyFPa26CTaJmCHGHpexZz65oMx5fSk6NUGoOn8J 7VAtTW9UUruzgxrtfZ2IBYKNWrCLPVG5S+3PyuterpE+uodn7uknQ4WpXwFZMHO9v1bEHZY JK0xHXHvJ7Y= X-QQ-GoodBg: 2 X-BIZMAIL-ID: 2181088627799291 From: Dawei Li To: will@kernel.org, mark.rutland@arm.com, yury.norov@gmail.com, linux@rasmusvillemoes.dk Cc: xueshuai@linux.alibaba.com, renyu.zj@linux.alibaba.com, yangyicong@hisilicon.com, jonathan.cameron@huawei.com, andersson@kernel.org, konrad.dybcio@linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Dawei Li Subject: [PATCH v3 04/10] perf/arm_cspmu: Avoid placing cpumask on the stack Date: Wed, 3 Apr 2024 23:59:44 +0800 Message-Id: <20240403155950.2068109-5-dawei.li@shingroup.cn> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20240403155950.2068109-1-dawei.li@shingroup.cn> References: <20240403155950.2068109-1-dawei.li@shingroup.cn> MIME-Version: 1.0 X-QQ-SENDSIZE: 520 Feedback-ID: bizesmtp:shingroup.cn:qybglogicsvrgz:qybglogicsvrgz5a-1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240403_090207_634064_6026A213 X-CRM114-Status: GOOD ( 10.92 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org In general it's preferable to avoid placing cpumasks on the stack, as for large values of NR_CPUS these can consume significant amounts of stack space and make stack overflows more likely. Use cpumask_any_and_but() to avoid the need for a temporary cpumask on the stack. Suggested-by: Mark Rutland Reviewed-by: Mark Rutland Signed-off-by: Dawei Li --- drivers/perf/arm_cspmu/arm_cspmu.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/perf/arm_cspmu/arm_cspmu.c b/drivers/perf/arm_cspmu/arm_cspmu.c index b9a252272f1e..fd1004251665 100644 --- a/drivers/perf/arm_cspmu/arm_cspmu.c +++ b/drivers/perf/arm_cspmu/arm_cspmu.c @@ -1322,8 +1322,7 @@ static int arm_cspmu_cpu_online(unsigned int cpu, struct hlist_node *node) static int arm_cspmu_cpu_teardown(unsigned int cpu, struct hlist_node *node) { - int dst; - struct cpumask online_supported; + unsigned int dst; struct arm_cspmu *cspmu = hlist_entry_safe(node, struct arm_cspmu, cpuhp_node); @@ -1333,9 +1332,8 @@ static int arm_cspmu_cpu_teardown(unsigned int cpu, struct hlist_node *node) return 0; /* Choose a new CPU to migrate ownership of the PMU to */ - cpumask_and(&online_supported, &cspmu->associated_cpus, - cpu_online_mask); - dst = cpumask_any_but(&online_supported, cpu); + dst = cpumask_any_and_but(&cspmu->associated_cpus, + cpu_online_mask, cpu); if (dst >= nr_cpu_ids) return 0;