Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753543AbbBZItB (ORCPT ); Thu, 26 Feb 2015 03:49:01 -0500 Received: from www.linutronix.de ([62.245.132.108]:47762 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753286AbbBZIs7 (ORCPT ); Thu, 26 Feb 2015 03:48:59 -0500 Date: Thu, 26 Feb 2015 09:48:50 +0100 From: Sebastian Andrzej Siewior To: Joakim Hernberg Cc: Daniel Wagner , John Kacur , linux-rt-users , LKML , Thomas Gleixner , rostedt@goodmis.org Subject: Re: [ANNOUNCE] 3.18.7-rt1 Message-ID: <20150226084850.GA12992@linutronix.de> References: <20150216111822.GA21649@linutronix.de> <54E2FDD8.8090008@monom.org> <20150219103601.7e40d0af@tor.valhalla.alchemy.lu> <20150225135501.GA6823@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20150225135501.GA6823@linutronix.de> X-Key-Id: 97C4700B X-Key-Fingerprint: 09E2 D1F3 9A3A FF13 C3D3 961C 0688 1C1E 97C4 700B User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4808 Lines: 155 * Sebastian Andrzej Siewior | 2015-02-25 14:55:01 [+0100]: >Okay. I applied a slightly modified version of it. That init() is >From 8334ac498f104c00e5d93e3e83d3bcec1a993cec Mon Sep 17 00:00:00 2001 From: Daniel Wagner Date: Tue, 17 Feb 2015 09:37:44 +0100 Subject: [PATCH] thermal: Defer thermal wakups to threads On RT the spin lock in pkg_temp_thermal_platfrom_thermal_notify will call schedule while we run in irq context. [] dump_stack+0x4e/0x8f [] __schedule_bug+0xa6/0xb4 [] __schedule+0x5b4/0x700 [] schedule+0x2a/0x90 [] rt_spin_lock_slowlock+0xe5/0x2d0 [] rt_spin_lock+0x25/0x30 [] pkg_temp_thermal_platform_thermal_notify+0x45/0x134 [x86_pkg_temp_thermal] [] ? therm_throt_process+0x1b/0x160 [] intel_thermal_interrupt+0x211/0x250 [] smp_thermal_interrupt+0x21/0x40 [] thermal_interrupt+0x6d/0x80 Let's defer the work to a kthread. Signed-off-by: Daniel Wagner [bigeasy: reoder init/denit position. TODO: flush swork on exit] Signed-off-by: Sebastian Andrzej Siewior --- drivers/thermal/x86_pkg_temp_thermal.c | 51 ++++++++++++++++++++++++++++++++-- 1 file changed, 48 insertions(+), 3 deletions(-) diff --git a/drivers/thermal/x86_pkg_temp_thermal.c b/drivers/thermal/x86_pkg_temp_thermal.c index 9ea3d9d49ffc..ab7c400a9d5c 100644 --- a/drivers/thermal/x86_pkg_temp_thermal.c +++ b/drivers/thermal/x86_pkg_temp_thermal.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include @@ -352,7 +353,7 @@ static void pkg_temp_thermal_threshold_work_fn(struct work_struct *work) } } -static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val) +static void platform_thermal_notify_work(struct swork_event *event) { unsigned long flags; int cpu = smp_processor_id(); @@ -369,7 +370,7 @@ static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val) pkg_work_scheduled[phy_id]) { disable_pkg_thres_interrupt(); spin_unlock_irqrestore(&pkg_work_lock, flags); - return -EINVAL; + return; } pkg_work_scheduled[phy_id] = 1; spin_unlock_irqrestore(&pkg_work_lock, flags); @@ -378,9 +379,48 @@ static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val) schedule_delayed_work_on(cpu, &per_cpu(pkg_temp_thermal_threshold_work, cpu), msecs_to_jiffies(notify_delay_ms)); +} + +#ifdef CONFIG_PREEMPT_RT_FULL +static struct swork_event notify_work; + +static int thermal_notify_work_init(void) +{ + int err; + + err = swork_get(); + if (!err) + return err; + + INIT_SWORK(¬ify_work, platform_thermal_notify_work); return 0; } +static void thermal_notify_work_cleanup(void) +{ + swork_put(); +} + +static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val) +{ + swork_queue(¬ify_work); + return 0; +} + +#else /* !CONFIG_PREEMPT_RT_FULL */ + +static int thermal_notify_work_init(void) { return 0; } + +static int thermal_notify_work_cleanup(void) { } + +static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val) +{ + platform_thermal_notify_work(NULL); + + return 0; +} +#endif /* CONFIG_PREEMPT_RT_FULL */ + static int find_siblings_cpu(int cpu) { int i; @@ -584,6 +624,9 @@ static int __init pkg_temp_thermal_init(void) if (!x86_match_cpu(pkg_temp_thermal_ids)) return -ENODEV; + if (!thermal_notify_work_init()) + return -ENODEV; + spin_lock_init(&pkg_work_lock); platform_thermal_package_notify = pkg_temp_thermal_platform_thermal_notify; @@ -594,6 +637,7 @@ static int __init pkg_temp_thermal_init(void) for_each_online_cpu(i) if (get_core_online(i)) goto err_ret; + __register_hotcpu_notifier(&pkg_temp_thermal_notifier); cpu_notifier_register_done(); @@ -608,7 +652,7 @@ static int __init pkg_temp_thermal_init(void) kfree(pkg_work_scheduled); platform_thermal_package_notify = NULL; platform_thermal_package_rate_control = NULL; - + thermal_notify_work_cleanup(); return -ENODEV; } @@ -633,6 +677,7 @@ static void __exit pkg_temp_thermal_exit(void) mutex_unlock(&phy_dev_list_mutex); platform_thermal_package_notify = NULL; platform_thermal_package_rate_control = NULL; + thermal_notify_work_cleanup(); for_each_online_cpu(i) cancel_delayed_work_sync( &per_cpu(pkg_temp_thermal_threshold_work, i)); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/