Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751164AbbKPF1Z (ORCPT ); Mon, 16 Nov 2015 00:27:25 -0500 Received: from mail5.windriver.com ([192.103.53.11]:40214 "EHLO mail5.wrs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750828AbbKPF1V (ORCPT ); Mon, 16 Nov 2015 00:27:21 -0500 Message-ID: <56496912.4090001@windriver.com> Date: Mon, 16 Nov 2015 13:26:42 +0800 From: yjin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Thomas Gleixner CC: Steven Rostedt , , , , , , , , Yang Shi Subject: Re: [RT PATCH] sched: rt: fix two possible deadlocks in push_irq_work_func References: <1447469598-31876-1-git-send-email-yanjiang.jin@windriver.com> <20151113232512.53df431f@gandalf.local.home> <5646BB4A.50307@windriver.com> In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2813 Lines: 90 Hi Thomas, Thanks for your help. I have tested your patch this morning, it seems well. Could you tell me when will you send your formal patch? And please CC me when you send your patch. Regards! Yanjiang On 2015年11月15日 19:05, Thomas Gleixner wrote: > On Sun, 15 Nov 2015, Thomas Gleixner wrote: >> Which does not happen on MIPS as it uses the generic >> arch_irq_work_has_interrupt() implementation which returns 'false'. > So the proper fix is to ensure that the irq safe irq work actually > happens in interrupt context. Patch below. > > Thanks, > > tglx > > 8<------------- > > diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h > index 0e427a9997f3..2543aab05daa 100644 > --- a/include/linux/irq_work.h > +++ b/include/linux/irq_work.h > @@ -52,4 +52,10 @@ static inline bool irq_work_needs_cpu(void) { return false; } > static inline void irq_work_run(void) { } > #endif > > +#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL) > +void irq_work_tick_soft(void); > +#else > +static inline void irq_work_tick_soft(void) { } > +#endif > + > #endif /* _LINUX_IRQ_WORK_H */ > diff --git a/kernel/irq_work.c b/kernel/irq_work.c > index 5a0f4525139c..58cf46638ca0 100644 > --- a/kernel/irq_work.c > +++ b/kernel/irq_work.c > @@ -200,8 +200,17 @@ void irq_work_tick(void) > > if (!llist_empty(raised) && !arch_irq_work_has_interrupt()) > irq_work_run_list(raised); > + > + if (!IS_ENABLED(CONFIG_PREEMPT_RT_FULL)) > + irq_work_run_list(this_cpu_ptr(&lazy_list)); > +} > + > +#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL) > +void irq_work_tick_soft(void) > +{ > irq_work_run_list(this_cpu_ptr(&lazy_list)); > } > +#endif > > /* > * Synchronize against the irq_work @entry, ensures the entry is not > diff --git a/kernel/time/timer.c b/kernel/time/timer.c > index adb1d82d6631..c68ba873da3c 100644 > --- a/kernel/time/timer.c > +++ b/kernel/time/timer.c > @@ -1455,7 +1455,7 @@ void update_process_times(int user_tick) > scheduler_tick(); > run_local_timers(); > rcu_check_callbacks(user_tick); > -#if defined(CONFIG_IRQ_WORK) && !defined(CONFIG_PREEMPT_RT_FULL) > +#if defined(CONFIG_IRQ_WORK) > if (in_irq()) > irq_work_tick(); > #endif > @@ -1471,9 +1471,7 @@ static void run_timer_softirq(struct softirq_action *h) > > hrtimer_run_pending(); > > -#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL) > - irq_work_tick(); > -#endif > + irq_work_tick_soft(); > > if (time_after_eq(jiffies, base->timer_jiffies)) > __run_timers(base); -- 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/