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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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <23882bd6-c0e0-4f6c-9000-b79216194198@efficios.com> 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 >