Message-ID: <1514737989.1967.24.camel@perches.com>
Subject: Re: [PATCH] arch/x86/boot: sizeof macro
From: Joe Perches <joe@perches.com>
To: Andy Shevchenko <andy.shevchenko@gmail.com>,
        Ingo Molnar <mingo@kernel.org>
Cc: Saidgani Musaev <cpu808694@gmail.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Thomas Gleixner <tglx@linutronix.de>,
        x86@kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Date: Sun, 31 Dec 2017 08:33:09 -0800
In-Reply-To: <CAHp75VdhZqRdRb2GJd4QnRoG6brYvfswZ6wR_pWEk+T-uJ3i5A@mail.gmail.com>
References: <20171229183015.7772-1-cpu808694@gmail.com>
         <CAHp75Vc0V_ZVsPzhE=78y9gZ91=sE1hXR_98d9-1TNcTHLy0SQ@mail.gmail.com>
         <20171229194614.3iku5zg5oglrd2cl@gmail.com>
         <CAHp75VdhZqRdRb2GJd4QnRoG6brYvfswZ6wR_pWEk+T-uJ3i5A@mail.gmail.com>
Content-Type: text/plain; charset="ISO-8859-1"
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 982
Lines: 32

On Sun, 2017-12-31 at 13:48 +0200, Andy Shevchenko wrote:
> On Fri, Dec 29, 2017 at 9:46 PM, Ingo Molnar <mingo@kernel.org> wrote:
> > * Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
> > > > -       ireg.cx  = sizeof buf;
> > > > +       ireg.cx  = sizeof(buf);
> > > 
> > > sizeof is operator, not a function.
> > > So, what are you trying to achieve?
> > 
> > That's true, but in the kernel coding style we use it as a function:
> 
> Yeah, the question is do we need to change all those 177 occurrences at all?

There's actually around 900, for ~100:1 ratio

$ git grep -P "\bsizeof\s+\w" -- "*.[ch]" | wc -l
907
$ git grep -P "\bsizeof\s*\(" -- "*.[ch]" | wc -l
117203

About half of these occurrences are in 3 paths
and their actual uses of sizeof without and with
parenthesis are:

drivers/infiniband/	212:3696
drivers/media/		111:5058
drivers/usb/		121:2006

> Or perhaps it might be an opportunity during some other changes to
> certain users...

Perhaps best that way.