Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <20181102152637.GA3105@hp-pavilion-15-notebook-pc-brajeswar>
 <20181102182905.3klrdw4dxapeoiib@tower> <CAFqt6zYmBFQ7gDJJkYAhPzPYyLGsDqOdr8ctXmYbd7e9sv75xg@mail.gmail.com>
In-Reply-To: <CAFqt6zYmBFQ7gDJJkYAhPzPYyLGsDqOdr8ctXmYbd7e9sv75xg@mail.gmail.com>
From:   Matt Turner <mattst88@gmail.com>
Date:   Fri, 2 Nov 2018 12:01:18 -0700
Message-ID: <CAEdQ38Fh99QmusGbEBi9TjUKQbQDX90pEaUC5Y=s-BL=RQ3o_A@mail.gmail.com>
Subject: Re: [PATCH] include/asm/cmpxchg.h: Remove duplicate header
To:     jrdr.linux@gmail.com
Cc:     Michael Cree <mcree@orcon.net.nz>, brajeswar.linux@gmail.com,
        Richard Henderson <rth@twiddle.net>,
        Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
        Andrea Parri <parri.andrea@gmail.com>,
        Ingo Molnar <mingo@kernel.org>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        linux-alpha <linux-alpha@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>, sabyasachi.linux@gmail.com
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Fri, Nov 2, 2018 at 11:55 AM Souptick Joarder <jrdr.linux@gmail.com> wrote:
> We run the static analyser "make includecheck" which list out files where
> duplicate headers can be removed and based on that we thought to remove
> from this file. Didn't understood about the existence of second include ??


#define ____xchg(type, args...)         __xchg ## type ## _local(args)
#define ____cmpxchg(type, args...)      __cmpxchg ## type ## _local(args)
#include <asm/xchg.h>
[snip]
#undef ____xchg
#undef ____cmpxchg
#define ____xchg(type, args...)         __xchg ##type(args)
#define ____cmpxchg(type, args...)      __cmpxchg ##type(args)
#include <asm/xchg.h>

asm/xchg.h has a comment at the top that says

/*
 * xchg/xchg_local and cmpxchg/cmpxchg_local share the same code
 * except that local version do not have the expensive memory barrier.
 * So this file is included twice from asm/cmpxchg.h.
 */