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[103.168.172.201]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-45c9f290162sm12661021cf.3.2024.09.27.16.21.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 27 Sep 2024 16:21:09 -0700 (PDT) Received: from phl-compute-01.internal (phl-compute-01.phl.internal [10.202.2.41]) by mailfauth.phl.internal (Postfix) with ESMTP id E1EA01200043; Fri, 27 Sep 2024 19:21:08 -0400 (EDT) Received: from phl-mailfrontend-01 ([10.202.2.162]) by phl-compute-01.internal (MEProxy); Fri, 27 Sep 2024 19:21:08 -0400 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeeftddrvddutddgvddvucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdggtfgfnhhsuhgsshgtrhhisggvpdfu rfetoffkrfgpnffqhgenuceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnh htshculddquddttddmnecujfgurhepfffhvfevuffkfhggtggujgesthdtredttddtvden ucfhrhhomhepuehoqhhunhcuhfgvnhhguceosghoqhhunhdrfhgvnhhgsehgmhgrihhlrd gtohhmqeenucggtffrrghtthgvrhhnpedttddugeeuveeghffgueffteffueehkeegtdff feehhfejfffhgfefgeegteeghfenucffohhmrghinhepvghffhhitghiohhsrdgtohhmne cuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepsghoqhhu nhdomhgvshhmthhprghuthhhphgvrhhsohhnrghlihhthidqieelvdeghedtieegqdduje ejkeehheehvddqsghoqhhunhdrfhgvnhhgpeepghhmrghilhdrtghomhesfhhigihmvgdr nhgrmhgvpdhnsggprhgtphhtthhopedvledpmhhouggvpehsmhhtphhouhhtpdhrtghpth htohepmhgrthhhihgvuhdruggvshhnohihvghrshesvghffhhitghiohhsrdgtohhmpdhr tghpthhtohepthhorhhvrghlughssehlihhnuhigqdhfohhunhgurghtihhonhdrohhrgh dprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhr ghdprhgtphhtthhopehgrhgvghhkhheslhhinhhugihfohhunhgurghtihhonhdrohhrgh dprhgtphhtthhopegsihhgvggrshihsehlihhnuhhtrhhonhhigidruggvpdhrtghpthht ohepphgruhhlmhgtkheskhgvrhhnvghlrdhorhhgpdhrtghpthhtohepfihilhhlsehkvg hrnhgvlhdrohhrghdprhgtphhtthhopehpvghtvghriiesihhnfhhrrgguvggrugdrohhr ghdprhgtphhtthhopehsthgvrhhnsehrohiflhgrnhgurdhhrghrvhgrrhgurdgvughu X-ME-Proxy: Feedback-ID: iad51458e:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 27 Sep 2024 19:21:08 -0400 (EDT) Date: Fri, 27 Sep 2024 16:20:18 -0700 From: Boqun Feng To: Mathieu Desnoyers Cc: Linus Torvalds , linux-kernel@vger.kernel.org, Greg Kroah-Hartman , Sebastian Andrzej Siewior , "Paul E. McKenney" , Will Deacon , Peter Zijlstra , Alan Stern , John Stultz , Neeraj Upadhyay , Frederic Weisbecker , Joel Fernandes , Josh Triplett , Uladzislau Rezki , Steven Rostedt , Lai Jiangshan , Zqiang , Ingo Molnar , Waiman Long , Mark Rutland , Thomas Gleixner , Vlastimil Babka , maged.michael@gmail.com, Mateusz Guzik , rcu@vger.kernel.org, linux-mm@kvack.org, lkmm@lists.linux.dev Subject: Re: [RFC PATCH] compiler.h: Introduce ptr_eq() to preserve address dependency Message-ID: References: <20240927203334.976821-1-mathieu.desnoyers@efficios.com> <23882bd6-c0e0-4f6c-9000-b79216194198@efficios.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <23882bd6-c0e0-4f6c-9000-b79216194198@efficios.com> X-Stat-Signature: 4ea7wt6nrtjmbsuh1ao61cdd49yyyutn X-Rspamd-Queue-Id: 3CADE40002 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1727479271-532453 X-HE-Meta: U2FsdGVkX1/ldBvEXzkgTkYR+WE2gr9eW/vOgsQtcWfJ+0+RrQu/RqDQw7gfRIjtTiFG5a+QTIe+0tTv4TY8eKscGQpiag0N4vwQ19IcNkpykrsHhr5+HdKR8hdr6aZWUvSj8i7CeHZNqPCeSVyxfUAY9En5T1G/zNObGRkHmYcL86ajk8TXdMk1Zw3xSmAO4YK7neLbzDLZLNjsU64mW8MhyC/BOtuY/L4nmPQksWgNwX9mwOhfSCr2jCTEGrAKKtgOlaq/eUoUJNz0RW86xJ/asmxFIC/C45qJYswa82Ly6i9+VYoVvtyMu7JnPCrVbFAuHyzlb1YUN1pBXZmWhKGBtqWemw6TEgDy1GUn4BWxmlFYUDb63FjrYPY/eK1YmQor6TOA5xU+kL4I74qq3Stp1epUDk/kyV3Z8IauyipcV2yTqrUJQQj2Q+OXT7hN+mN6obrlJw46lyK3DY4GRrKAq9EEUndbskVbPof3uGB2KJiizlJ61SpQFd7lOOXu7Hk8kjr0DgcLNsjX6Vi3OC+7Cj34G+6g//Lo9g4oW1F+JdfXNuIpRQXfCALTrxjQNYWcec7jEttw5spaV3D0LkbbXn3wU8FS+F4uYBOO43xBEb1K3tqReYdjtzdQHyjR4wWy+G/S4KLsbXloBbr3ftdF5SGRZkpyESbzbSEoWwWk2rX7omTLEmPZUY7t+voB3CPA+iMMeC0QxtHPI8p4i2uE2qm/MjdoEIycQ6mjNMkrX+neKjyivTslkrTx/2ZwHOyodVu2cU0WD8Gb0zlNNcdR3AJ87mlF9Itrp86wxKwFdA9es/qBgRJNi0cpCfBhrGZggUJgLML1yPrEwyDoCxv76EzCGlqpeC1oF0PJFQpBFQrGDGrBSOh6Alqw0TRYY3YB2J66CFEKE05opmzcO2B2HHW+9LgBJVKokijAqbHfsEB4po7XEDrk9Uzd4weznTiQs6L5C0AEO5q6dCR BA59FFLD MFxmXYAeEi9M7Bg9lr12oUn4LGyZruFdn3S7lojTFSTU/0+ZDVokd2f2CTWc4riukXe5lqjM6SeiYn3rYxRhWyFM2awXBN8YHUaiV8TXqcbtmfi0zPdwRXFK+u9lbAOYixNbg4crBk9pgghj+8XaoxVpYZsOqKt3z8Xbu8mTvG12lxH6xOghyvu1usk7tGk8l3SA1+TyY5BSPSyiqmaynFIb4IHrgsPwY6/GamsbQ314vzd9NrVU56acLnAfeBnathi1ul4NiVJYZ0f7joYfC0xS9iLYlEZLITB93l610iuplDERWkNNMVsTv5yU8c2lqTvGIkz2rxSDn2XsNYWZEeUf041Ws2gR8KIn7KJb0dTB0bkodrbmzu5lO+uGmq1UW2UhYMdhVQ6j157MBwZFg+C38B7qiPsJ0C75jkgr7GmjWxEVpn1lrbsMpAQGXdNsiG74nrdXvHB9op/IEh3qkpLfWbC5HtK2fLk5yNBu9UhLq4fPtFFoi8gz+2PeZEnFGn76hZc3KI282h/S6S9fgjAoEFaTAE/4O/+KNqTbCyO+FR2jwM/WZpecUCKm9ZI//VwwMx5f+g3s3/76r3qDY2cmvHw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Sep 27, 2024 at 07:05:53PM -0400, Mathieu Desnoyers wrote: > On 2024-09-27 22:33, Mathieu Desnoyers wrote: > [...] > > > --- > > include/linux/compiler.h | 62 ++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 62 insertions(+) > > > > I'm wondering if this really belongs in compiler.h, or if it's so > RCU/HP specific that it should be implemented in rcupdate.h ? > > [... ] > > +static __always_inline > > +int ptr_eq(const volatile void *a, const volatile void *b) > > And perhaps rename this to rcu_ptr_eq() ? > I think the current place and name is fine, yes RCU is the most important address dependency user, but there are other users as well. Regards, Boqun > Thanks, > > Mathieu > > > +{ > > + OPTIMIZER_HIDE_VAR(a); > > + OPTIMIZER_HIDE_VAR(b); > > + return a == b; > > +} > > + > > > > -- > Mathieu Desnoyers > EfficiOS Inc. > https://www.efficios.com >