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From: Grygorii Strashko <grygorii.strashko@ti.com>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	LKML <linux-kernel@vger.kernel.org>,
	linux-rt-users <linux-rt-users@vger.kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [ANNOUNCE] v4.14.29-rt25
Date: Tue, 1 May 2018 10:04:13 -0500	[thread overview]
Message-ID: <8933b3b9-7f70-0f3f-a8b8-19d4369b35d4@ti.com> (raw)
In-Reply-To: <20180423191023.qtinidsq4vj3lmha@linutronix.de>

Hi Sebastian,

On 04/23/2018 02:10 PM, Sebastian Andrzej Siewior wrote:
> On 2018-04-23 11:57:39 [-0500], Grygorii Strashko wrote:
>> Sry, but I can't apply it. What's you base?
> 
> please try this patch and latest v4.14-RT

I've tried this (with  v4.14.34-rt27) and I do not see rcu_note_context_switch() any more.

Sry, it took some time as i found some instability -
test "stress-ng --class os --all 0 -t 5m " not always finished :(
So, I've tried to rollback to v4.14.29-rt25 and use as TI RT kernel as
pure rt-devel. Still not sure if this is some sort of regression or not.

> 
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index e305a8f8cd7d..0322503084a5 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -600,6 +600,9 @@ struct task_struct {
>   	int				migrate_disable_atomic;
>   # endif
>   #endif
> +#ifdef CONFIG_PREEMPT_RT_FULL
> +	int				sleeping_lock;
> +#endif
>   
>   #ifdef CONFIG_PREEMPT_RCU
>   	int				rcu_read_lock_nesting;
> @@ -1757,6 +1760,23 @@ static __always_inline bool need_resched(void)
>   	return unlikely(tif_need_resched());
>   }
>   
> +#ifdef CONFIG_PREEMPT_RT_FULL
> +static inline void sleeping_lock_inc(void)
> +{
> +	current->sleeping_lock++;
> +}
> +
> +static inline void sleeping_lock_dec(void)
> +{
> +	current->sleeping_lock--;
> +}
> +
> +#else
> +
> +static inline void sleeping_lock_inc(void) { }
> +static inline void sleeping_lock_dec(void) { }
> +#endif
> +
>   /*
>    * Wrappers for p->thread_info->cpu access. No-op on UP.
>    */
> diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
> index 0cb716ba3be0..bac3fb580af6 100644
> --- a/kernel/locking/rtmutex.c
> +++ b/kernel/locking/rtmutex.c
> @@ -1141,6 +1141,7 @@ void __sched rt_spin_lock_slowunlock(struct rt_mutex *lock)
>   
>   void __lockfunc rt_spin_lock(spinlock_t *lock)
>   {
> +	sleeping_lock_inc();
>   	migrate_disable();
>   	spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
>   	rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
> @@ -1155,6 +1156,7 @@ void __lockfunc __rt_spin_lock(struct rt_mutex *lock)
>   #ifdef CONFIG_DEBUG_LOCK_ALLOC
>   void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass)
>   {
> +	sleeping_lock_inc();
>   	migrate_disable();
>   	spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
>   	rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
> @@ -1168,6 +1170,7 @@ void __lockfunc rt_spin_unlock(spinlock_t *lock)
>   	spin_release(&lock->dep_map, 1, _RET_IP_);
>   	rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock);
>   	migrate_enable();
> +	sleeping_lock_dec();
>   }
>   EXPORT_SYMBOL(rt_spin_unlock);
>   
> @@ -1193,12 +1196,15 @@ int __lockfunc rt_spin_trylock(spinlock_t *lock)
>   {
>   	int ret;
>   
> +	sleeping_lock_inc();
>   	migrate_disable();
>   	ret = __rt_mutex_trylock(&lock->lock);
> -	if (ret)
> +	if (ret) {
>   		spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
> -	else
> +	} else {
>   		migrate_enable();
> +		sleeping_lock_dec();
> +	}
>   	return ret;
>   }
>   EXPORT_SYMBOL(rt_spin_trylock);
> @@ -1210,6 +1216,7 @@ int __lockfunc rt_spin_trylock_bh(spinlock_t *lock)
>   	local_bh_disable();
>   	ret = __rt_mutex_trylock(&lock->lock);
>   	if (ret) {
> +		sleeping_lock_inc();
>   		migrate_disable();
>   		spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
>   	} else
> @@ -1225,6 +1232,7 @@ int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags)
>   	*flags = 0;
>   	ret = __rt_mutex_trylock(&lock->lock);
>   	if (ret) {
> +		sleeping_lock_inc();
>   		migrate_disable();
>   		spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
>   	}
> diff --git a/kernel/locking/rwlock-rt.c b/kernel/locking/rwlock-rt.c
> index aebb7ce25bc6..f2e155b2c4a8 100644
> --- a/kernel/locking/rwlock-rt.c
> +++ b/kernel/locking/rwlock-rt.c
> @@ -305,12 +305,15 @@ int __lockfunc rt_read_trylock(rwlock_t *rwlock)
>   {
>   	int ret;
>   
> +	sleeping_lock_inc();
>   	migrate_disable();
>   	ret = do_read_rt_trylock(rwlock);
> -	if (ret)
> +	if (ret) {
>   		rwlock_acquire_read(&rwlock->dep_map, 0, 1, _RET_IP_);
> -	else
> +	} else {
>   		migrate_enable();
> +		sleeping_lock_dec();
> +	}
>   	return ret;
>   }
>   EXPORT_SYMBOL(rt_read_trylock);
> @@ -319,18 +322,22 @@ int __lockfunc rt_write_trylock(rwlock_t *rwlock)
>   {
>   	int ret;
>   
> +	sleeping_lock_inc();
>   	migrate_disable();
>   	ret = do_write_rt_trylock(rwlock);
> -	if (ret)
> +	if (ret) {
>   		rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
> -	else
> +	} else {
>   		migrate_enable();
> +		sleeping_lock_dec();
> +	}
>   	return ret;
>   }
>   EXPORT_SYMBOL(rt_write_trylock);
>   
>   void __lockfunc rt_read_lock(rwlock_t *rwlock)
>   {
> +	sleeping_lock_inc();
>   	migrate_disable();
>   	rwlock_acquire_read(&rwlock->dep_map, 0, 0, _RET_IP_);
>   	do_read_rt_lock(rwlock);
> @@ -339,6 +346,7 @@ EXPORT_SYMBOL(rt_read_lock);
>   
>   void __lockfunc rt_write_lock(rwlock_t *rwlock)
>   {
> +	sleeping_lock_inc();
>   	migrate_disable();
>   	rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_);
>   	do_write_rt_lock(rwlock);
> @@ -350,6 +358,7 @@ void __lockfunc rt_read_unlock(rwlock_t *rwlock)
>   	rwlock_release(&rwlock->dep_map, 1, _RET_IP_);
>   	do_read_rt_unlock(rwlock);
>   	migrate_enable();
> +	sleeping_lock_dec();
>   }
>   EXPORT_SYMBOL(rt_read_unlock);
>   
> @@ -358,6 +367,7 @@ void __lockfunc rt_write_unlock(rwlock_t *rwlock)
>   	rwlock_release(&rwlock->dep_map, 1, _RET_IP_);
>   	do_write_rt_unlock(rwlock);
>   	migrate_enable();
> +	sleeping_lock_dec();
>   }
>   EXPORT_SYMBOL(rt_write_unlock);
>   
> diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
> index 3315ebad932f..c6098f60e641 100644
> --- a/kernel/rcu/tree_plugin.h
> +++ b/kernel/rcu/tree_plugin.h
> @@ -301,13 +301,13 @@ static void rcu_preempt_note_context_switch(bool preempt)
>   	struct task_struct *t = current;
>   	struct rcu_data *rdp;
>   	struct rcu_node *rnp;
> -	int mg_counter = 0;
> +	int sleeping_l = 0;
>   
>   	RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_preempt_note_context_switch() invoked with interrupts enabled!!!\n");
> -#if defined(CONFIG_PREEMPT_RT_BASE)
> -	mg_counter = t->migrate_disable;
> +#if defined(CONFIG_PREEMPT_RT_FULL)
> +	sleeping_l = t->sleeping_lock;
>   #endif
> -	WARN_ON_ONCE(!preempt && t->rcu_read_lock_nesting > 0 && !mg_counter);
> +	WARN_ON_ONCE(!preempt && t->rcu_read_lock_nesting > 0 && !sleeping_l);
>   	if (t->rcu_read_lock_nesting > 0 &&
>   	    !t->rcu_read_unlock_special.b.blocked) {
>   
> diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
> index ce2c2d04cbaa..b59e009087a9 100644
> --- a/kernel/time/hrtimer.c
> +++ b/kernel/time/hrtimer.c
> @@ -1870,7 +1870,9 @@ void cpu_chill(void)
>   	chill_time = ktime_set(0, NSEC_PER_MSEC);
>   	set_current_state(TASK_UNINTERRUPTIBLE);
>   	current->flags |= PF_NOFREEZE;
> +	sleeping_lock_inc();
>   	schedule_hrtimeout(&chill_time, HRTIMER_MODE_REL_HARD);
> +	sleeping_lock_dec();
>   	if (!freeze_flag)
>   		current->flags &= ~PF_NOFREEZE;
>   }
> 
> Sebastian
> 

-- 
regards,
-grygorii

  reply	other threads:[~2018-05-01 15:04 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-25 10:12 Sebastian Andrzej Siewior
2018-03-27 18:01 ` Grygorii Strashko
2018-04-20 17:11   ` Sebastian Andrzej Siewior
2018-04-23 16:57     ` Grygorii Strashko
2018-04-23 19:10       ` Sebastian Andrzej Siewior
2018-05-01 15:04         ` Grygorii Strashko [this message]
2018-05-03 15:24           ` Sebastian Andrzej Siewior
2018-05-03 18:26             ` Grygorii Strashko

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