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From: Thomas Gleixner <tglx@linutronix.de>
To: Peter Zijlstra <peterz@infradead.org>
Cc: mingo@kernel.org, juri.lelli@arm.com, rostedt@goodmis.org,
	xlpang@redhat.com, bigeasy@linutronix.de,
	linux-kernel@vger.kernel.org, mathieu.desnoyers@efficios.com,
	jdesfossez@efficios.com, bristot@redhat.com
Subject: Re: [RFC][PATCH 4/4] futex: Rewrite FUTEX_UNLOCK_PI
Date: Sat, 8 Oct 2016 20:22:38 +0200 (CEST)	[thread overview]
Message-ID: <alpine.DEB.2.20.1610082019430.5222@nanos> (raw)
In-Reply-To: <20161007112143.GJ3117@twins.programming.kicks-ass.net>

On Fri, 7 Oct 2016, Peter Zijlstra wrote:
> +		/*
> +		 * Grab a reference on the pi_state and drop hb->lock.
> +		 *
> +		 * The reference ensures pi_state lives, dropping the hb->lock
> +		 * is tricky.. wake_futex_pi() will take rt_mutex::wait_lock to
> +		 * close the races against futex_lock_pi(), but in case of
> +		 * _any_ fail we'll abort and retry the whole deal.
> +		 */
> +		WARN_ON_ONCE(!atomic_inc_not_zero(&pi_state->refcount));
> +		spin_unlock(&hb->lock);
> +
> +		ret = wake_futex_pi(uaddr, uval, pi_state);
> +
> +		put_pi_state(pi_state);
> +
>  		/*
>  		 * In case of success wake_futex_pi dropped the hash
>  		 * bucket lock.

This comment has become stale.

Thanks,

	tglx

  parent reply	other threads:[~2016-10-08 18:25 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-03  9:12 [RFC][PATCH 0/4] FUTEX_UNLOCK_PI wobbles Peter Zijlstra
2016-10-03  9:12 ` [RFC][PATCH 1/4] futex: Cleanup variable names for futex_top_waiter() Peter Zijlstra
2016-10-03 14:15   ` Steven Rostedt
2016-10-05  3:58   ` Davidlohr Bueso
2016-10-03  9:12 ` [RFC][PATCH 2/4] futex: Use smp_store_release() in mark_wake_futex() Peter Zijlstra
2016-10-03 14:19   ` Steven Rostedt
2016-10-05  3:57   ` Davidlohr Bueso
2016-10-05  6:20     ` Peter Zijlstra
2016-10-03  9:12 ` [RFC][PATCH 3/4] futex: Remove rt_mutex_deadlock_account_*() Peter Zijlstra
2016-10-03  9:34   ` Peter Zijlstra
2016-10-03 14:25   ` Steven Rostedt
2016-10-05  1:08   ` Davidlohr Bueso
2016-10-05  7:29   ` Sebastian Andrzej Siewior
2016-10-03  9:12 ` [RFC][PATCH 4/4] futex: Rewrite FUTEX_UNLOCK_PI Peter Zijlstra
2016-10-03 15:36   ` Steven Rostedt
2016-10-03 15:44     ` Peter Zijlstra
2016-10-03 15:45     ` Peter Zijlstra
2016-10-03 16:23       ` Steven Rostedt
2016-10-05  7:41   ` Sebastian Andrzej Siewior
2016-10-05  8:09     ` Peter Zijlstra
2016-10-05  8:21       ` Sebastian Andrzej Siewior
2016-10-05  8:32         ` Peter Zijlstra
2016-10-06 10:29   ` Peter Zijlstra
2016-10-07 11:21   ` Peter Zijlstra
2016-10-08 15:53     ` Thomas Gleixner
2016-10-08 16:55       ` Peter Zijlstra
2016-10-08 17:06         ` Thomas Gleixner
2016-10-10 10:17         ` Thomas Gleixner
2016-10-10 11:40           ` Peter Zijlstra
2016-10-21 12:27           ` Peter Zijlstra
2016-10-27 20:36             ` Thomas Gleixner
2016-11-23 19:20               ` Peter Zijlstra
2016-11-24 16:52                 ` Peter Zijlstra
2016-11-24 17:56                   ` Thomas Gleixner
2016-11-24 18:58                     ` Peter Zijlstra
2016-11-25  9:23                       ` Peter Zijlstra
2016-11-25 10:03                         ` Peter Zijlstra
2016-11-25 19:13                           ` Thomas Gleixner
2016-11-25 14:09               ` Peter Zijlstra
2016-10-08 18:22     ` Thomas Gleixner [this message]
2016-10-09 11:17     ` Thomas Gleixner
2016-10-10 14:06       ` Peter Zijlstra
2016-10-05  1:02 ` [RFC][PATCH 0/4] FUTEX_UNLOCK_PI wobbles Davidlohr Bueso
2016-10-05  6:20   ` Peter Zijlstra
2016-10-05  7:26     ` Sebastian Andrzej Siewior
2016-10-05 16:04     ` Davidlohr Bueso

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