From mboxrd@z Thu Jan 1 00:00:00 1970 From: peterz@infradead.org Subject: Re: [PATCH] tools/memory-model: document the "one-time init" pattern Date: Mon, 20 Jul 2020 18:48:50 +0200 Message-ID: <20200720164850.GF119549@hirez.programming.kicks-ass.net> References: <20200717044427.68747-1-ebiggers@kernel.org> <20200718014204.GN5369@dread.disaster.area> <20200718140811.GA1179836@rowland.harvard.edu> <20200720013320.GP5369@dread.disaster.area> <20200720145211.GC1228057@rowland.harvard.edu> <20200720153911.GX12769@casper.infradead.org> <20200720160433.GQ9247@paulmck-ThinkPad-P72> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20200720160433.GQ9247@paulmck-ThinkPad-P72> Sender: linux-fsdevel-owner@vger.kernel.org To: "Paul E. McKenney" Cc: Matthew Wilcox , Alan Stern , Dave Chinner , Eric Biggers , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org, Akira Yokosawa , Andrea Parri , Boqun Feng , Daniel Lustig , "Darrick J . Wong" , David Howells , Jade Alglave , Luc Maranget , Nicholas Piggin , Will Deacon List-Id: linux-arch.vger.kernel.org On Mon, Jul 20, 2020 at 09:04:34AM -0700, Paul E. McKenney wrote: > 2. If we were to say "unlock" instead of "release", consistency > would demand that we also say "lock" instead of "acquire". > But "lock" is subtlely different than "acquire", and there is > a history of people requesting further divergence. This, acquire/release are RCpc, while (with the exception of Power) LOCK/UNLOCK are RCsc. ( Or did we settle on RCtso for our release/acquire order? I have vague memories of a long-ish thread, but seem to have forgotten the outcome, if any. ) Lots of subtlety and head-aches right about there. Anyway, it would be awesome if we can get Power into the RCsc locking camp :-) From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49696 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728890AbgGTQtQ (ORCPT ); Mon, 20 Jul 2020 12:49:16 -0400 Date: Mon, 20 Jul 2020 18:48:50 +0200 From: peterz@infradead.org Subject: Re: [PATCH] tools/memory-model: document the "one-time init" pattern Message-ID: <20200720164850.GF119549@hirez.programming.kicks-ass.net> References: <20200717044427.68747-1-ebiggers@kernel.org> <20200718014204.GN5369@dread.disaster.area> <20200718140811.GA1179836@rowland.harvard.edu> <20200720013320.GP5369@dread.disaster.area> <20200720145211.GC1228057@rowland.harvard.edu> <20200720153911.GX12769@casper.infradead.org> <20200720160433.GQ9247@paulmck-ThinkPad-P72> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200720160433.GQ9247@paulmck-ThinkPad-P72> Sender: linux-arch-owner@vger.kernel.org List-ID: To: "Paul E. McKenney" Cc: Matthew Wilcox , Alan Stern , Dave Chinner , Eric Biggers , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org, Akira Yokosawa , Andrea Parri , Boqun Feng , Daniel Lustig , "Darrick J . Wong" , David Howells , Jade Alglave , Luc Maranget , Nicholas Piggin , Will Deacon Message-ID: <20200720164850.UBFxRfxEA-ScFaQvoP8Aw33fjOKawncTzmY_1lIaR3s@z> On Mon, Jul 20, 2020 at 09:04:34AM -0700, Paul E. McKenney wrote: > 2. If we were to say "unlock" instead of "release", consistency > would demand that we also say "lock" instead of "acquire". > But "lock" is subtlely different than "acquire", and there is > a history of people requesting further divergence. This, acquire/release are RCpc, while (with the exception of Power) LOCK/UNLOCK are RCsc. ( Or did we settle on RCtso for our release/acquire order? I have vague memories of a long-ish thread, but seem to have forgotten the outcome, if any. ) Lots of subtlety and head-aches right about there. Anyway, it would be awesome if we can get Power into the RCsc locking camp :-)