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From: Peter Zijlstra <peterz@infradead.org>
To: Waiman Long <longman@redhat.com>
Cc: Yongji Xie <elohimes@gmail.com>,
	mingo@redhat.com, will.deacon@arm.com,
	linux-kernel@vger.kernel.org, xieyongji@baidu.com,
	zhangyu31@baidu.com, liuqi16@baidu.com, yuanlinsi01@baidu.com,
	nixun@baidu.com, lilin24@baidu.com,
	Davidlohr Bueso <dave@stgolabs.net>
Subject: Re: [RFC] locking/rwsem: Avoid issuing wakeup before setting the reader waiter to nil
Date: Thu, 29 Nov 2018 19:13:12 +0100	[thread overview]
Message-ID: <20181129181312.GC11632@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <aa425caf-a080-3b67-22eb-15c5b5bbad85@redhat.com>

On Thu, Nov 29, 2018 at 12:58:26PM -0500, Waiman Long wrote:
> OK, you convinced me. However, that can still lead to anonymous wakeups
> that can be problematic if it happens in certain places. Should we try
> to reduce anonymous wakeup as much as possible?

No, we should at all times accept and expect spurious wakeups.

  reply	other threads:[~2018-11-29 18:13 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-29 12:50 [RFC] locking/rwsem: Avoid issuing wakeup before setting the reader waiter to nil Yongji Xie
2018-11-29 13:12 ` Peter Zijlstra
2018-11-29 13:44   ` Peter Zijlstra
2018-11-29 14:02     ` Yongji Xie
2018-11-29 18:43     ` Davidlohr Bueso
2018-11-29 18:49       ` Waiman Long
2018-11-29 15:21   ` Waiman Long
2018-11-29 15:29     ` Waiman Long
2018-11-29 16:06     ` Peter Zijlstra
2018-11-29 17:02       ` Waiman Long
2018-11-29 17:27         ` Peter Zijlstra
2018-11-29 17:58           ` Waiman Long
2018-11-29 18:13             ` Peter Zijlstra [this message]
2018-11-29 18:17               ` Davidlohr Bueso
2018-11-29 18:08           ` Peter Zijlstra
2018-11-29 18:26             ` Waiman Long
2018-11-29 18:31               ` Will Deacon
2018-11-29 18:34                 ` Waiman Long
2018-11-29 22:05                   ` Peter Zijlstra
2018-11-30  9:34                     ` 答复: " Liu,Qi(ACU-T1)
2018-11-30 14:15                       ` Peter Zijlstra
2018-11-29 21:30               ` Davidlohr Bueso
2018-11-29 21:34                 ` Davidlohr Bueso
2018-11-29 22:17                   ` Peter Zijlstra
2018-11-30  9:30                     ` Andrea Parri
2018-12-03  5:31                     ` [PATCH -tip] kernel/sched,wake_q: Branch predict wake_q_add() cmpxchg Davidlohr Bueso
2018-12-03 16:10                       ` Waiman Long
2019-01-21 11:28                       ` [tip:locking/core] sched/wake_q: Add branch prediction hint to " tip-bot for Davidlohr Bueso
2018-12-10 15:12                     ` [RFC] locking/rwsem: Avoid issuing wakeup before setting the reader waiter to nil Yongji Xie
2018-12-17 11:37                       ` Peter Zijlstra
2018-12-17 13:12                         ` Yongji Xie
2019-01-07 14:35                           ` Waiman Long
2019-01-07 15:31                             ` Peter Zijlstra
2019-01-07 15:35                               ` Waiman Long
2018-12-17 20:53                         ` Davidlohr Bueso
2018-12-18 13:10                           ` Peter Zijlstra
2018-12-18 13:14                             ` Peter Zijlstra
2018-12-18 17:27                               ` Davidlohr Bueso
2018-12-18 18:54                               ` [PATCH v2] sched/wake_q: Reduce reference counting for special users Davidlohr Bueso
2018-12-18 19:17                                 ` Waiman Long
2018-12-18 19:30                                   ` Davidlohr Bueso
2018-12-18 19:39                                     ` Davidlohr Bueso
2018-12-18 19:53                                       ` [PATCH v4] " Davidlohr Bueso
2018-12-18 20:35                                         ` Waiman Long
2019-01-21 16:02                                           ` Davidlohr Bueso
2019-01-22  8:55                                             ` Peter Zijlstra
2019-02-04  8:57                                         ` [tip:locking/core] " tip-bot for Davidlohr Bueso
2019-02-07 19:30                                           ` Davidlohr Bueso
2019-02-12 14:14                                           ` Daniel Vacek
2019-01-21 11:28 ` [tip:locking/core] locking/rwsem: Fix (possible) missed wakeup tip-bot for Xie Yongji

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