From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755904AbcK1VrZ (ORCPT ); Mon, 28 Nov 2016 16:47:25 -0500 Received: from mga11.intel.com ([192.55.52.93]:23833 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755524AbcK1Vqp (ORCPT ); Mon, 28 Nov 2016 16:46:45 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,565,1473145200"; d="scan'208";a="36490942" From: Jacob Pan To: LKML , Linux PM , Rafael Wysocki , Eduardo Valentin , Zhang Rui Cc: Peter Zijlstra , Ingo Molnar , Thomas Gleixner , Arjan van de Ven , Srinivas Pandruvada , Len Brown , Petr Mladek , Sebastian Andrzej Siewior Subject: [PATCH 3/4] thermal/intel_powerclamp: Convert to CPU hotplug state Date: Mon, 28 Nov 2016 13:44:51 -0800 Message-Id: <1480369492-23901-4-git-send-email-jacob.jun.pan@linux.intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1480369492-23901-1-git-send-email-jacob.jun.pan@linux.intel.com> References: <1480369492-23901-1-git-send-email-jacob.jun.pan@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 | 73 +++++++++++++++++++------------------- 1 file changed, 36 insertions(+), 37 deletions(-) diff --git a/drivers/thermal/intel_powerclamp.c b/drivers/thermal/intel_powerclamp.c index 22971da..1310283 100644 --- a/drivers/thermal/intel_powerclamp.c +++ b/drivers/thermal/intel_powerclamp.c @@ -43,7 +43,6 @@ #include #include #include -#include #include #include #include @@ -530,8 +529,7 @@ static void start_power_clamp_worker(unsigned long cpu) struct powerclamp_worker_data *w_data = per_cpu_ptr(worker_data, cpu); struct kthread_worker *worker; - worker = kthread_create_worker_on_cpu(cpu, KTW_FREEZABLE, - "kidle_inject/%ld", cpu); + worker = kthread_create_worker_on_cpu(cpu, 0, "kidle_inject/%ld", cpu); if (IS_ERR(worker)) return; @@ -622,43 +620,35 @@ 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) { @@ -785,6 +775,8 @@ 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; @@ -802,7 +794,14 @@ 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) { @@ -827,7 +826,7 @@ 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; @@ -836,8 +835,8 @@ 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); -- 1.9.1