From mboxrd@z Thu Jan 1 00:00:00 1970 From: Davidlohr Bueso 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 Message-ID: <20160824040007.GA17186@linux-80c1.suse> References: <1471554672-38662-1-git-send-email-Waiman.Long@hpe.com> <1471554672-38662-11-git-send-email-Waiman.Long@hpe.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Return-path: Content-Disposition: inline In-Reply-To: <1471554672-38662-11-git-send-email-Waiman.Long@hpe.com> Sender: linux-ia64-owner@vger.kernel.org To: Waiman Long Cc: Peter Zijlstra , Ingo Molnar , 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 , Dave Chinner , Jonathan Corbet , Scott J Norton , Douglas Hatch List-Id: linux-arch.vger.kernel.org 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:54052 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750912AbcHXEAT (ORCPT ); Wed, 24 Aug 2016 00:00:19 -0400 Date: Tue, 23 Aug 2016 21:00:07 -0700 From: Davidlohr Bueso Subject: Re: [RFC PATCH-tip v4 10/10] locking/rwsem: Add a boot parameter to reader spinning threshold Message-ID: <20160824040007.GA17186@linux-80c1.suse> References: <1471554672-38662-1-git-send-email-Waiman.Long@hpe.com> <1471554672-38662-11-git-send-email-Waiman.Long@hpe.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <1471554672-38662-11-git-send-email-Waiman.Long@hpe.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Waiman Long Cc: Peter Zijlstra , Ingo Molnar , 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 , Dave Chinner , Jonathan Corbet , Scott J Norton , Douglas Hatch Message-ID: <20160824040007.ZsXF4jmPqgKLYvOaDEvTsyxd_oeUAMy4C6LyCEWv4HI@z> 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