From patchwork Fri Jan 22 07:19:01 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shilpasri G Bhat X-Patchwork-Id: 8087991 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id B7FDEBEEE5 for ; Fri, 22 Jan 2016 07:20:39 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E1B6320434 for ; Fri, 22 Jan 2016 07:20:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8402A20443 for ; Fri, 22 Jan 2016 07:20:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751344AbcAVHU3 (ORCPT ); Fri, 22 Jan 2016 02:20:29 -0500 Received: from e23smtp06.au.ibm.com ([202.81.31.148]:39896 "EHLO e23smtp06.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751468AbcAVHUI (ORCPT ); Fri, 22 Jan 2016 02:20:08 -0500 Received: from localhost by e23smtp06.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Fri, 22 Jan 2016 17:20:05 +1000 X-IBM-Helo: d23dlp03.au.ibm.com X-IBM-MailFrom: shilpa.bhat@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org;linux-pm@vger.kernel.org Received: from d23relay10.au.ibm.com (d23relay10.au.ibm.com [9.190.26.77]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id 8EA9A3578053; Fri, 22 Jan 2016 18:20:04 +1100 (EST) Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay10.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u0M7JuZT1180152; Fri, 22 Jan 2016 18:20:04 +1100 Received: from d23av01.au.ibm.com (localhost [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u0M7JU6V023343; Fri, 22 Jan 2016 18:19:31 +1100 Received: from localhost.in.ibm.com ([9.79.217.113]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u0M7JNsl022822; Fri, 22 Jan 2016 18:19:28 +1100 From: Shilpasri G Bhat To: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org Cc: rjw@rjwysocki.net, viresh.kumar@linaro.org, linux-pm@vger.kernel.org, pc@us.ibm.com, anton@samba.org, ego@linux.vnet.ibm.com, shreyas@linux.vnet.ibm.com, Shilpasri G Bhat Subject: [PATCH v6 1/5] cpufreq: powernv: Hot-plug safe the kworker thread Date: Fri, 22 Jan 2016 12:49:01 +0530 Message-Id: <1453447145-17722-2-git-send-email-shilpa.bhat@linux.vnet.ibm.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1453447145-17722-1-git-send-email-shilpa.bhat@linux.vnet.ibm.com> References: <1453447145-17722-1-git-send-email-shilpa.bhat@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16012207-0021-0000-0000-000002944CFC Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In the kworker_thread powernv_cpufreq_work_fn(), we can end up sending an IPI to a cpu going offline. This is a rare corner case which is fixed using {get/put}_online_cpus(). Along with this fix, this patch adds changes to do oneshot cpumask_{clear/and} operation. Suggested-by: Shreyas B Prabhu Suggested-by: Gautham R Shenoy Signed-off-by: Shilpasri G Bhat Reviewed-by: Gautham R. Shenoy Acked-by: Viresh Kumar --- Changes form v5: - Fix the kbuild-error: drivers/cpufreq/powernv-cpufreq.c:428:2: error: implicit declaration of function 'get_online_cpus' [-Werror=implicit-function-declaration drivers/cpufreq/powernv-cpufreq.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c index 547890f..140c75f 100644 --- a/drivers/cpufreq/powernv-cpufreq.c +++ b/drivers/cpufreq/powernv-cpufreq.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include @@ -423,18 +424,19 @@ void powernv_cpufreq_work_fn(struct work_struct *work) { struct chip *chip = container_of(work, struct chip, throttle); unsigned int cpu; - cpumask_var_t mask; + cpumask_t mask; - smp_call_function_any(&chip->mask, + get_online_cpus(); + cpumask_and(&mask, &chip->mask, cpu_online_mask); + smp_call_function_any(&mask, powernv_cpufreq_throttle_check, NULL, 0); if (!chip->restore) - return; + goto out; chip->restore = false; - cpumask_copy(mask, &chip->mask); - for_each_cpu_and(cpu, mask, cpu_online_mask) { - int index, tcpu; + for_each_cpu(cpu, &mask) { + int index; struct cpufreq_policy policy; cpufreq_get_policy(&policy, cpu); @@ -442,9 +444,10 @@ void powernv_cpufreq_work_fn(struct work_struct *work) policy.cur, CPUFREQ_RELATION_C, &index); powernv_cpufreq_target_index(&policy, index); - for_each_cpu(tcpu, policy.cpus) - cpumask_clear_cpu(tcpu, mask); + cpumask_andnot(&mask, &mask, policy.cpus); } +out: + put_online_cpus(); } static char throttle_reason[][30] = {