From: Davidlohr Bueso <dave@stgolabs.net>
To: Waiman Long <Waiman.Long@hpe.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org, x86@kernel.org,
linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org,
linux-s390@vger.kernel.org, linux-arch@vger.kernel.org,
linux-doc@vger.kernel.org, Jason Low <jason.low2@hp.com>,
Dave Chinner <david@fromorbit.com>,
Jonathan Corbet <corbet@lwn.net>,
Scott J Norton <scott.norton@hpe.com>,
Douglas Hatch <doug.hatch@hpe.com>
Subject: Re: [RFC PATCH-tip v4 10/10] locking/rwsem: Add a boot parameter to reader spinning threshold
Date: Tue, 23 Aug 2016 21:00:07 -0700 [thread overview]
Message-ID: <20160824040007.GA17186@linux-80c1.suse> (raw)
In-Reply-To: <1471554672-38662-11-git-send-email-Waiman.Long@hpe.com>
On Thu, 18 Aug 2016, Waiman Long wrote:
>The default reader spining threshold is current set to 4096. However,
>the right reader spinning threshold may vary from one system to
>another and among the different architectures. This patch adds a new
>kernel boot parameter to modify the threshold value. This enables
>better tailoring to the needs of different systems as well as for
>testing purposes.
It also means that those systems could very easily be incorrectly tailored.
(and worse case scenario: reboot, is obviously a terrible way to get rid
of any issues). I very much disagree with exposing this sort of core stuff,
it should work well for everyone out of the box, not relying on users to
properly configure this.
Thanks,
Davidlohr
next prev parent reply other threads:[~2016-08-24 4:00 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-18 21:11 [RFC PATCH-tip v4 00/10] locking/rwsem: Enable reader optimistic spinning Waiman Long
2016-08-18 21:11 ` Waiman Long
2016-08-18 21:11 ` [RFC PATCH-tip v4 01/10] locking/osq: Make lock/unlock proper acquire/release barrier Waiman Long
2016-08-18 21:11 ` Waiman Long
2016-10-04 19:06 ` Davidlohr Bueso
2016-10-04 19:06 ` Davidlohr Bueso
2016-10-04 21:28 ` Jason Low
2016-10-04 21:28 ` Jason Low
2016-10-05 12:19 ` Waiman Long
2016-10-05 12:19 ` Waiman Long
2016-10-05 15:11 ` Waiman Long
2016-10-06 5:47 ` Davidlohr Bueso
2016-10-06 19:30 ` Waiman Long
2016-10-06 19:30 ` Waiman Long
2016-10-10 5:39 ` [PATCH] locking/osq: Provide proper lock/unlock and relaxed flavors Davidlohr Bueso
2016-10-10 5:39 ` Davidlohr Bueso
2016-10-06 19:31 ` [RFC PATCH-tip v4 01/10] locking/osq: Make lock/unlock proper acquire/release barrier Jason Low
2016-08-18 21:11 ` [RFC PATCH-tip v4 02/10] locking/rwsem: Stop active read lock ASAP Waiman Long
2016-10-06 18:17 ` Davidlohr Bueso
2016-10-06 18:17 ` Davidlohr Bueso
2016-10-06 21:47 ` Dave Chinner
2016-10-06 21:47 ` Dave Chinner
2016-10-06 22:51 ` Davidlohr Bueso
2016-10-07 21:45 ` Waiman Long
2016-10-07 21:45 ` Waiman Long
2016-10-09 15:17 ` Christoph Hellwig
2016-10-09 15:17 ` Christoph Hellwig
2016-10-10 6:07 ` Dave Chinner
2016-10-10 9:34 ` Christoph Hellwig
2016-10-10 9:34 ` Christoph Hellwig
2016-10-11 21:06 ` Dave Chinner
2016-10-11 21:06 ` Dave Chinner
2016-10-16 5:57 ` Christoph Hellwig
2016-10-16 5:57 ` Christoph Hellwig
2016-08-18 21:11 ` [RFC PATCH-tip v4 03/10] locking/rwsem: Make rwsem_spin_on_owner() return a tri-state value Waiman Long
2016-08-18 21:11 ` Waiman Long
2016-08-18 21:11 ` [RFC PATCH-tip v4 04/10] locking/rwsem: Enable count-based spinning on reader Waiman Long
2016-08-18 21:11 ` Waiman Long
2016-08-18 21:11 ` [RFC PATCH-tip v4 05/10] locking/rwsem: move down rwsem_down_read_failed function Waiman Long
2016-08-18 21:11 ` Waiman Long
2016-08-18 21:11 ` [RFC PATCH-tip v4 06/10] locking/rwsem: Move common rwsem macros to asm-generic/rwsem_types.h Waiman Long
2016-08-18 21:11 ` Waiman Long
2016-08-18 21:11 ` [RFC PATCH-tip v4 07/10] locking/rwsem: Change RWSEM_WAITING_BIAS for better disambiguation Waiman Long
2016-08-18 21:11 ` Waiman Long
2016-08-19 5:57 ` Wanpeng Li
2016-08-19 5:57 ` Wanpeng Li
2016-08-19 16:21 ` Waiman Long
2016-08-19 16:21 ` Waiman Long
2016-08-22 2:15 ` Wanpeng Li
2016-08-22 2:15 ` Wanpeng Li
2016-08-18 21:11 ` [RFC PATCH-tip v4 08/10] locking/rwsem: Enable spinning readers Waiman Long
2016-08-18 21:11 ` Waiman Long
2016-08-18 21:11 ` [RFC PATCH-tip v4 09/10] locking/rwsem: Enable reactivation of reader spinning Waiman Long
2016-08-18 21:11 ` Waiman Long
2016-08-18 21:11 ` [RFC PATCH-tip v4 10/10] locking/rwsem: Add a boot parameter to reader spinning threshold Waiman Long
2016-08-18 21:11 ` Waiman Long
2016-08-24 1:46 ` [lkp] [locking/rwsem] INFO: rcu_preempt detected stalls on CPUs/tasks kernel test robot
2016-08-24 4:00 ` Davidlohr Bueso [this message]
2016-08-24 4:00 ` [RFC PATCH-tip v4 10/10] locking/rwsem: Add a boot parameter to reader spinning threshold Davidlohr Bueso
2016-08-24 18:39 ` Waiman Long
2016-08-24 18:39 ` Waiman Long
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