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McKenney" To: Mathieu Desnoyers Cc: Linus Torvalds , linux-kernel@vger.kernel.org, Boqun Feng , Greg Kroah-Hartman , Sebastian Andrzej Siewior , 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: <55678fb6-4476-4e25-82d5-5d5ad5b7e7d9@paulmck-laptop> Reply-To: paulmck@kernel.org 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-Rspamd-Server: rspam03 X-Rspam-User: X-Rspamd-Queue-Id: 39D484000F X-Stat-Signature: ezg4kkq3hq4owrb537ogppd74jf1e1mt X-HE-Tag: 1727523126-460383 X-HE-Meta: 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 pEd11MzI 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 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() ? For either location or name: Acked-by: Paul E. McKenney There are non-RCU uses, but RCU is currently by far the most common. Thanx, Paul > Thanks, > > Mathieu > > > +{ > > + OPTIMIZER_HIDE_VAR(a); > > + OPTIMIZER_HIDE_VAR(b); > > + return a == b; > > +} > > + > > > > -- > Mathieu Desnoyers > EfficiOS Inc. > https://www.efficios.com >