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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 ACEFBC43603 for ; Tue, 10 Dec 2019 13:55:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8270B207FF for ; Tue, 10 Dec 2019 13:55:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727426AbfLJNzn (ORCPT ); Tue, 10 Dec 2019 08:55:43 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:7659 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727007AbfLJNzn (ORCPT ); Tue, 10 Dec 2019 08:55:43 -0500 Received: from DGGEMS408-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id E958DF45AE7025AA0D1E; Tue, 10 Dec 2019 21:55:36 +0800 (CST) Received: from [127.0.0.1] (10.177.223.23) by DGGEMS408-HUB.china.huawei.com (10.3.19.208) with Microsoft SMTP Server id 14.3.439.0; Tue, 10 Dec 2019 21:55:29 +0800 Subject: Re: [PATCH] perf/smmuv3: Remove the leftover put_cpu() in error path To: Will Deacon CC: Mark Rutland , Robin Murphy , Shameer Kolothum , , References: <1575974784-55046-1-git-send-email-guohanjun@huawei.com> <20191210132458.GA19183@willie-the-truck> From: Hanjun Guo Message-ID: Date: Tue, 10 Dec 2019 21:55:28 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <20191210132458.GA19183@willie-the-truck> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.223.23] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/12/10 21:24, Will Deacon wrote: > On Tue, Dec 10, 2019 at 06:46:24PM +0800, Hanjun Guo wrote: >> In smmu_pmu_probe(), there is put_cpu() in the error path, >> which is wrong because we use raw_smp_processor_id() to >> get the cpu ID, not get_cpu(), remove it. >> >> Signed-off-by: Hanjun Guo >> --- >> drivers/perf/arm_smmuv3_pmu.c | 1 - >> 1 file changed, 1 deletion(-) >> >> diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c >> index 773128f..fd1d46a 100644 >> --- a/drivers/perf/arm_smmuv3_pmu.c >> +++ b/drivers/perf/arm_smmuv3_pmu.c >> @@ -834,7 +834,6 @@ static int smmu_pmu_probe(struct platform_device *pdev) >> out_unregister: >> cpuhp_state_remove_instance_nocalls(cpuhp_state_num, &smmu_pmu->node); >> out_cpuhp_err: >> - put_cpu(); >> return err; > > Can we kill 'out_cpuhp_err' altogether then and just return err if we fail > to add the hotplug instance? Makes sense, but I think we can go further to kill both 'out_cpuhp_err' and 'out_register' as below [1], what do you think? Thanks Hanjun [1]: diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c index fd1d46a..a5adaba 100644 --- a/drivers/perf/arm_smmuv3_pmu.c +++ b/drivers/perf/arm_smmuv3_pmu.c @@ -814,14 +814,15 @@ static int smmu_pmu_probe(struct platform_device *pdev) if (err) { dev_err(dev, "Error %d registering hotplug, PMU @%pa\n", err, &res_0->start); - goto out_cpuhp_err; + return err; } err = perf_pmu_register(&smmu_pmu->pmu, name, -1); if (err) { + cpuhp_state_remove_instance_nocalls(cpuhp_state_num, &smmu_pmu->node); dev_err(dev, "Error %d registering PMU @%pa\n", err, &res_0->start); - goto out_unregister; + return err; } dev_info(dev, "Registered PMU @ %pa using %d counters with %s filter settings\n", @@ -830,11 +831,6 @@ static int smmu_pmu_probe(struct platform_device *pdev) "Individual"); return 0; - -out_unregister: - cpuhp_state_remove_instance_nocalls(cpuhp_state_num, &smmu_pmu->node); -out_cpuhp_err: - return err; } static int smmu_pmu_remove(struct platform_device *pdev)