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From: Tejun Heo <tj@kernel.org>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Prateek Sood <prsood@codeaurora.org>,
	Peter Zijlstra <peterz@infradead.org>,
	avagin@gmail.com, mingo@kernel.org, linux-kernel@vger.kernel.org,
	cgroups@vger.kernel.org, sramana@codeaurora.org
Subject: Re: [PATCH] cgroup/cpuset: fix circular locking dependency
Date: Tue, 9 Jan 2018 07:37:52 -0800	[thread overview]
Message-ID: <20180109153752.GI3668920@devbig577.frc2.facebook.com> (raw)
In-Reply-To: <20180109152112.GT9671@linux.vnet.ibm.com>

Hello, Paul.

On Tue, Jan 09, 2018 at 07:21:12AM -0800, Paul E. McKenney wrote:
> > The code was previously using both system_power_efficient_wq and
> > system_workqueue (for the expedited path).  I guess the options were
> > either using two workqueues or dropping POWER_EFFICIENT.  I have no
> > idea how big an impact this will make or whether it'd even be
> > noticeable but maybe it'd be worthwhile to mention that in the
> > description?
> 
> Good point!  How about if I change the last paragraph of the commit
> log to read as follows?
> 
> 							Thanx, Paul
> 
> ------------------------------------------------------------------------
> 
> This commit also causes SRCU to use this new RCU-specific
> workqueue_struct.  Note that SRCU's use of workqueues never blocks them
> waiting for readers, so this should be safe from a forward-progress
> viewpoint.  Note that this moves SRCU from system_power_efficient_wq
> to a normal workqueue.  In the unlikely event that this results in 
> measurable degradation, a separate power-efficient workqueue will be
> creates for SRCU.

Sounds good.  Please feel free to add

 Acked-by: Tejun Heo <tj@kernel.org>

Thanks.

-- 
tejun

  reply	other threads:[~2018-01-09 15:38 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-28  1:22 cgroup/for-next: WARNING: possible circular locking dependency detected in cpuset_write_resmask Andrei Vagin
2017-11-28 11:35 ` [PATCH] cgroup/cpuset: fix circular locking dependency Prateek Sood
2017-12-04  5:14   ` Prateek Sood
2017-12-04  5:14     ` Prateek Sood
2017-12-04 20:22     ` Tejun Heo
2017-12-04 20:22       ` Tejun Heo
2017-12-04 22:58       ` Tejun Heo
2017-12-04 23:01         ` Peter Zijlstra
2017-12-04 23:01           ` Peter Zijlstra
2017-12-08  9:40           ` Prateek Sood
2017-12-08 11:45             ` Prateek Sood
2017-12-08 11:45               ` Prateek Sood
2017-12-11 15:32               ` Tejun Heo
2017-12-11 15:32                 ` Tejun Heo
2017-12-13 14:28                 ` Prateek Sood
2017-12-13 15:40                   ` Tejun Heo
2017-12-15  8:54                     ` Prateek Sood
2017-12-15  8:54                       ` Prateek Sood
2017-12-15 13:22                       ` Tejun Heo
2017-12-15 19:06                         ` Prateek Sood
2017-12-19  7:26                           ` [PATCH] cgroup: Fix deadlock in cpu hotplug path Prateek Sood
2017-12-19  7:26                             ` Prateek Sood
2017-12-19 13:39                             ` Tejun Heo
2017-12-11 15:20           ` [PATCH] cgroup/cpuset: fix circular locking dependency Tejun Heo
2017-12-11 15:20             ` Tejun Heo
2017-12-13  7:50             ` Prateek Sood
2017-12-13  7:50               ` Prateek Sood
2017-12-13 16:06               ` Tejun Heo
2017-12-15 19:04                 ` Prateek Sood
2017-12-15 19:04                   ` Prateek Sood
2017-12-28 20:37                 ` Prateek Sood
2017-12-28 20:37                   ` Prateek Sood
2018-01-02 16:16                   ` Tejun Heo
2018-01-02 17:44                     ` Paul E. McKenney
2018-01-02 17:44                       ` Paul E. McKenney
2018-01-02 18:01                       ` Paul E. McKenney
2018-01-08 12:28                         ` Tejun Heo
2018-01-08 12:28                           ` Tejun Heo
2018-01-08 13:47                           ` [PATCH wq/for-4.16 1/2] workqueue: separate out init_rescuer() Tejun Heo
2018-01-08 13:47                             ` Tejun Heo
2018-01-08 13:47                             ` [PATCH wq/for-4.16 2/2] workqueue: allow WQ_MEM_RECLAIM on early init workqueues Tejun Heo
2018-01-08 13:47                               ` Tejun Heo
2018-01-08 22:52                           ` [PATCH] cgroup/cpuset: fix circular locking dependency Paul E. McKenney
2018-01-08 22:52                             ` Paul E. McKenney
2018-01-09  0:31                             ` Paul E. McKenney
2018-01-09  3:42                               ` Tejun Heo
2018-01-09  3:42                                 ` Tejun Heo
2018-01-09  4:20                                 ` Paul E. McKenney
2018-01-09 13:44                                   ` Tejun Heo
2018-01-09 15:21                                     ` Paul E. McKenney
2018-01-09 15:21                                       ` Paul E. McKenney
2018-01-09 15:37                                       ` Tejun Heo [this message]
2018-01-09 16:00                                         ` Paul E. McKenney
2018-01-09 16:00                                           ` Paul E. McKenney
2018-01-10 20:08                                           ` Paul E. McKenney
2018-01-10 21:41                                             ` Tejun Heo
2018-01-10 21:41                                               ` Tejun Heo
2018-01-10 22:10                                               ` Paul E. McKenney
2018-01-10 22:10                                                 ` Paul E. McKenney
2018-01-15 12:02                     ` Prateek Sood
2018-01-15 12:02                       ` Prateek Sood
2018-01-16 16:27                       ` Tejun Heo

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