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From: Xunlei Pang <xpang@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	Juri Lelli <juri.lelli@arm.com>, Ingo Molnar <mingo@redhat.com>,
	Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH v3 2/6] sched/rtmutex/deadline: Fix a PI crash for deadline tasks
Date: Wed, 20 Apr 2016 21:49:42 +0800	[thread overview]
Message-ID: <571788F6.3020100@redhat.com> (raw)
In-Reply-To: <20160420131932.GC3430@twins.programming.kicks-ass.net>

On 2016/04/20 at 21:19, Peter Zijlstra wrote:
> On Thu, Apr 14, 2016 at 07:37:03PM +0800, Xunlei Pang wrote:
>> +	/* Updated under pi_lock and rtmutex lock */
>>  	struct rb_node *pi_waiters_leftmost;
>> +	struct rb_node *pi_waiters_leftmost_copy;
>>  struct task_struct *rt_mutex_get_top_task(struct task_struct *task)
>>  {
>> +	if (!task->pi_waiters_leftmost_copy)
>>  		return NULL;
>>  
>> +	return rb_entry(task->pi_waiters_leftmost_copy,
>> +				struct rt_mutex_waiter, pi_tree_entry)->task;
>>  }
> why ?! Why not keep a regular task_struct pointer and avoid this stuff?

I meant to make it semantically consistent, but I can change it since you think task_struct is better.

Regards,
Xunlei

  reply	other threads:[~2016-04-20 13:49 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-14 11:37 [PATCH v3 0/6] sched/deadline/rtmutex: Fix two deadline PI issues Xunlei Pang
2016-04-14 11:37 ` [PATCH v3 1/6] rtmutex: Deboost before waking up the top waiter Xunlei Pang
2016-04-18  8:23   ` Thomas Gleixner
2016-04-18  8:44     ` Xunlei Pang
2016-04-18  9:02       ` Thomas Gleixner
2016-04-18  9:41         ` Xunlei Pang
2016-04-20 12:20         ` Peter Zijlstra
2016-04-20 12:43           ` Thomas Gleixner
2016-04-20 13:10             ` Peter Zijlstra
2016-04-14 11:37 ` [PATCH v3 2/6] sched/rtmutex/deadline: Fix a PI crash for deadline tasks Xunlei Pang
2016-04-20 13:19   ` Peter Zijlstra
2016-04-20 13:49     ` Xunlei Pang [this message]
2016-04-22  3:26       ` Xunlei Pang
2016-04-14 11:37 ` [PATCH v3 3/6] rtmutex: Move "rt_mutex_waiter" definition to "include/linux/rtmutex.h" Xunlei Pang
2016-04-14 11:37 ` [PATCH v3 4/6] sched: Move dl_policy() to "include/linux/sched.h" Xunlei Pang
2016-04-14 11:37 ` [PATCH v3 5/6] sched/deadline/rtmutex: Fix unprotected PI access in enqueue_task_dl() Xunlei Pang
2016-04-14 15:31   ` Peter Zijlstra
2016-04-15  1:58     ` Xunlei Pang
2016-04-15  2:19       ` Xunlei Pang
2016-04-20 12:25         ` Peter Zijlstra
2016-04-20 13:00           ` Xunlei Pang
2016-04-20 13:17             ` Peter Zijlstra
2016-04-20 13:45               ` Xunlei Pang
2016-04-14 11:37 ` [PATCH v3 6/6] sched/deadline/rtmutex: Don't miss the dl_runtime/dl_period update Xunlei Pang
2017-03-23 14:56 [PATCH -v3 0/8] PI vs SCHED_DEADLINE fixes Peter Zijlstra
2017-03-23 14:56 ` [PATCH -v3 1/8] rtmutex: Deboost before waking up the top waiter Peter Zijlstra
2017-04-04  9:48   ` [tip:locking/core] " tip-bot for Xunlei Pang
2017-04-05  8:08     ` Mike Galbraith
2017-04-05 14:55       ` [tip:locking/core] Retiplockingcore_rtmutex_Deboost_before_waking_up_the_top_waiter tip-bot for Mike Galbraith
2017-04-05 15:03       ` [tip:locking/core] rtmutex: Plug preempt count leak in rt_mutex_futex_unlock() tip-bot for Mike Galbraith
2017-04-06  6:16       ` [tip:locking/core] rtmutex: Deboost before waking up the top waiter Xunlei Pang
2017-03-23 14:56 ` [PATCH -v3 2/8] sched/rtmutex/deadline: Fix a PI crash for deadline tasks Peter Zijlstra
2017-04-04  9:49   ` [tip:locking/core] " tip-bot for Xunlei Pang
2017-03-23 14:56 ` [PATCH -v3 3/8] sched/deadline/rtmutex: Dont miss the dl_runtime/dl_period update Peter Zijlstra
2017-04-04  9:50   ` [tip:locking/core] " tip-bot for Xunlei Pang
2017-03-23 14:56 ` [PATCH -v3 4/8] rtmutex: Clean up Peter Zijlstra
2017-03-23 18:21   ` Steven Rostedt
2017-04-04  9:50   ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-03-23 14:56 ` [PATCH -v3 5/8] sched/rtmutex: Refactor rt_mutex_setprio() Peter Zijlstra
2017-04-04  9:51   ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-03-23 14:56 ` [PATCH -v3 6/8] sched,tracing: Update trace_sched_pi_setprio() Peter Zijlstra
2017-04-04  9:51   ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-03-23 14:56 ` [PATCH -v3 7/8] rtmutex: Fix PI chain order integrity Peter Zijlstra
2017-04-04  9:52   ` [tip:locking/core] " tip-bot for Peter Zijlstra
2017-03-23 14:56 ` [PATCH -v3 8/8] rtmutex: Fix more prio comparisons Peter Zijlstra
2017-04-04  9:52   ` [tip:locking/core] " tip-bot for Peter Zijlstra

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