From patchwork Mon Oct 17 12:32:52 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Petr Mladek X-Patchwork-Id: 9379143 X-Patchwork-Delegate: rui.zhang@intel.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4561E600CA for ; Mon, 17 Oct 2016 12:34:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 36F9629269 for ; Mon, 17 Oct 2016 12:34:01 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2B3942926C; Mon, 17 Oct 2016 12:34:01 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AB10429269 for ; Mon, 17 Oct 2016 12:34:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934222AbcJQMd5 (ORCPT ); Mon, 17 Oct 2016 08:33:57 -0400 Received: from mx2.suse.de ([195.135.220.15]:38182 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934148AbcJQMdV (ORCPT ); Mon, 17 Oct 2016 08:33:21 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 4885AAD14; Mon, 17 Oct 2016 12:33:20 +0000 (UTC) From: Petr Mladek To: Jacob Pan , Zhang Rui , Thomas Gleixner Cc: Sebastian Andrzej Siewior , Eduardo Valentin , Tejun Heo , Peter Zijlstra , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Petr Mladek Subject: [PATCH 3/3] thermal/intel_powerclamp: Convert to CPU hotplug state Date: Mon, 17 Oct 2016 14:32:52 +0200 Message-Id: <1476707572-32215-4-git-send-email-pmladek@suse.com> X-Mailer: git-send-email 1.8.5.6 In-Reply-To: <1476707572-32215-1-git-send-email-pmladek@suse.com> References: <1476707572-32215-1-git-send-email-pmladek@suse.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Sebastian Andrzej Siewior This is a conversation to the new hotplug state machine with the difference that CPU_DEAD becomes CPU_PREDOWN. At the same time it makes the handling of the two states symmetrical. stop_power_clamp_worker() is called unconditionally and the controversial error message is removed. Finally, the hotplug state callbacks are removed after the powerclamping is stopped to avoid a potential race. Signed-off-by: Sebastian Andrzej Siewior [pmladek@suse.com: Fixed the possible race in powerclamp_exit()] Signed-off-by: Petr Mladek --- drivers/thermal/intel_powerclamp.c | 69 +++++++++++++++++++------------------- 1 file changed, 35 insertions(+), 34 deletions(-) diff --git a/drivers/thermal/intel_powerclamp.c b/drivers/thermal/intel_powerclamp.c index a94f7c849a4e..390e50b97324 100644 --- a/drivers/thermal/intel_powerclamp.c +++ b/drivers/thermal/intel_powerclamp.c @@ -622,43 +622,35 @@ static void end_power_clamp(void) } } -static int powerclamp_cpu_callback(struct notifier_block *nfb, - unsigned long action, void *hcpu) +static int powerclamp_cpu_online(unsigned int cpu) { - unsigned long cpu = (unsigned long)hcpu; + if (clamping == false) + return 0; + start_power_clamp_worker(cpu); + /* prefer BSP as controlling CPU */ + if (cpu == 0) { + control_cpu = 0; + smp_mb(); + } + return 0; +} - if (false == clamping) - goto exit_ok; +static int powerclamp_cpu_predown(unsigned int cpu) +{ + if (clamping == false) + return 0; - switch (action) { - case CPU_ONLINE: - start_power_clamp_worker(cpu); - /* prefer BSP as controlling CPU */ - if (cpu == 0) { - control_cpu = 0; - smp_mb(); - } - break; - case CPU_DEAD: - if (test_bit(cpu, cpu_clamping_mask)) { - pr_err("cpu %lu dead but powerclamping thread is not\n", - cpu); - stop_power_clamp_worker(cpu); - } - if (cpu == control_cpu) { - control_cpu = smp_processor_id(); - smp_mb(); - } - } + stop_power_clamp_worker(cpu); + if (cpu != control_cpu) + return 0; -exit_ok: - return NOTIFY_OK; + control_cpu = cpumask_first(cpu_online_mask); + if (control_cpu == cpu) + control_cpu = cpumask_next(cpu, cpu_online_mask); + smp_mb(); + return 0; } -static struct notifier_block powerclamp_cpu_notifier = { - .notifier_call = powerclamp_cpu_callback, -}; - static int powerclamp_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state) { @@ -788,6 +780,8 @@ static inline void powerclamp_create_debug_files(void) debugfs_remove_recursive(debug_dir); } +static enum cpuhp_state hp_state; + static int __init powerclamp_init(void) { int retval; @@ -805,7 +799,14 @@ static int __init powerclamp_init(void) /* set default limit, maybe adjusted during runtime based on feedback */ window_size = 2; - register_hotcpu_notifier(&powerclamp_cpu_notifier); + retval = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, + "thermal/intel_powerclamp:online", + powerclamp_cpu_online, + powerclamp_cpu_predown); + if (retval < 0) + goto exit_free; + + hp_state = retval; worker_data = alloc_percpu(struct powerclamp_worker_data); if (!worker_data) { @@ -830,7 +831,7 @@ static int __init powerclamp_init(void) exit_free_thread: free_percpu(worker_data); exit_unregister: - unregister_hotcpu_notifier(&powerclamp_cpu_notifier); + cpuhp_remove_state_nocalls(hp_state); exit_free: kfree(cpu_clamping_mask); return retval; @@ -839,8 +840,8 @@ static int __init powerclamp_init(void) static void __exit powerclamp_exit(void) { - unregister_hotcpu_notifier(&powerclamp_cpu_notifier); end_power_clamp(); + cpuhp_remove_state_nocalls(hp_state); free_percpu(worker_data); thermal_cooling_device_unregister(cooling_dev); kfree(cpu_clamping_mask);