Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [RFC][PATCH] rcu: Use typeof(p) instead of typeof(*p) *
To:     Steven Rostedt <rostedt@goodmis.org>,
        LKML <linux-kernel@vger.kernel.org>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Josh Triplett <josh@joshtriplett.org>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Lai Jiangshan <jiangshanlai@gmail.com>,
        Joel Fernandes <joel@joelfernandes.org>,
        Pablo Neira Ayuso <pablo@netfilter.org>,
        Jozsef Kadlecsik <kadlec@netfilter.org>,
        Florian Westphal <fw@strlen.de>,
        David Miller <davem@davemloft.net>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        David Ahern <dsahern@kernel.org>,
        Jakub Kicinski <kuba@kernel.org>, rcu@vger.kernel.org,
        netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
        netdev@vger.kernel.org
References: <20211005094728.203ecef2@gandalf.local.home>
From:   Rasmus Villemoes <linux@rasmusvillemoes.dk>
Message-ID: <ef5b1654-1f75-da82-cab8-248319efbe3f@rasmusvillemoes.dk>
Date:   Tue, 5 Oct 2021 20:01:59 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.13.0
MIME-Version: 1.0
In-Reply-To: <20211005094728.203ecef2@gandalf.local.home>
Content-Type: text/plain; charset=windows-1252
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 05/10/2021 15.47, Steven Rostedt wrote:

> That is, instead of declaring: typeof(*p) *_p; just do:
>  typeof(p) _p;
> 
> Also had to update a lot of the function pointer initialization in the
> networking code, as a function address must be passed as an argument in
> RCU_INIT_POINTER() 

I would think that one could avoid that churn by saying

  typeof((p) + 0)

instead of just "typeof(p)", to force the decay to a pointer.

Rasmus