From patchwork Mon Oct 21 13:28:18 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sudeep Holla X-Patchwork-Id: 11202193 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 78003913 for ; Mon, 21 Oct 2019 13:29:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 60257214B2 for ; Mon, 21 Oct 2019 13:29:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727322AbfJUN3B (ORCPT ); Mon, 21 Oct 2019 09:29:01 -0400 Received: from [217.140.110.172] ([217.140.110.172]:52642 "EHLO foss.arm.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1727152AbfJUN3B (ORCPT ); Mon, 21 Oct 2019 09:29:01 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A339C493; Mon, 21 Oct 2019 06:28:30 -0700 (PDT) Received: from usa.arm.com (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id D65B63F718; Mon, 21 Oct 2019 06:28:29 -0700 (PDT) From: Sudeep Holla To: viresh.kumar@linaro.org Cc: Sudeep Holla , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, rjw@rjwysocki.net Subject: [PATCH] cpufreq: Move cancelling of policy update work just after removing notifiers Date: Mon, 21 Oct 2019 14:28:18 +0100 Message-Id: <20191021132818.23787-1-sudeep.holla@arm.com> X-Mailer: git-send-email 2.17.1 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Commit 099967699ad9 ("cpufreq: Cancel policy update work scheduled before freeing") added cancel_work_sync(policy->update) after the frequency QoS were removed. We can cancel the work just after taking the last CPU in the policy offline and unregistering the notifiers as policy->update cannot be scheduled from anywhere at this point. However, due to other bugs, doing so still triggered the race between freeing of policy and scheduled policy update work. Now that all those issues are resolved, we can move this cancelling of any scheduled policy update work just after removing min/max notifiers. Signed-off-by: Sudeep Holla Acked-by: Viresh Kumar --- drivers/cpufreq/cpufreq.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) Hi Rafael, Based on Viresh's suggestion, I am posting a patch to move this cancel_work_sync earlier though it's not a must have change. I will leave it up to your preference. Regards, Sudeep diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 829a3764df1b..48a224a6b178 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1268,6 +1268,9 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy) freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN, &policy->nb_min); + /* Cancel any pending policy->update work before freeing the policy. */ + cancel_work_sync(&policy->update); + if (policy->max_freq_req) { /* * CPUFREQ_CREATE_POLICY notification is sent only after @@ -1279,8 +1282,6 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy) } freq_qos_remove_request(policy->min_freq_req); - /* Cancel any pending policy->update work before freeing the policy. */ - cancel_work_sync(&policy->update); kfree(policy->min_freq_req); cpufreq_policy_put_kobj(policy);