From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751957AbeBWPio (ORCPT ); Fri, 23 Feb 2018 10:38:44 -0500 Received: from www.llwyncelyn.cymru ([82.70.14.225]:55552 "EHLO fuzix.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751405AbeBWPim (ORCPT ); Fri, 23 Feb 2018 10:38:42 -0500 Date: Fri, 23 Feb 2018 15:38:07 +0000 From: Alan Cox To: Nikolay Borisov Cc: LKML , "Paul E. McKenney" , mathieu.desnoyers@efficios.com, Peter Zijlstra , parri.andrea@gmail.com Subject: Re: Reasoning about memory ordering Message-ID: <20180223153807.64666cfe@alans-desktop> In-Reply-To: <0db16ef6-c805-b1f6-527f-8fec149e3df5@suse.com> References: <0db16ef6-c805-b1f6-527f-8fec149e3df5@suse.com> Organization: Intel Corporation X-Mailer: Claws Mail 3.15.1-dirty (GTK+ 2.24.31; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Given this is the current state of the code (it's part of btrfs) I believe > the following could/should be done: Is there benchmarking data to show that a custom lock is justified (especiaally given it's going to mean btrfs and rtlinux don't play together nicely since it won't be able to see the mutex lock and do priority boosting ?) Alan