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From: Steven Rostedt <rostedt@goodmis.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: richard -rw- weinberger <richard.weinberger@gmail.com>,
	linux-kernel@vger.kernel.org, mingo@redhat.com,
	torvalds@linux-foundation.org, srostedt@redhat.com,
	tglx@linutronix.de, adobriyan@gmail.com,
	linux-tip-commits@vger.kernel.org
Subject: Re: [tip:core/urgent] WARN_ON_SMP(): Add comment to explain ({0;})
Date: Mon, 28 Mar 2011 11:09:00 -0400	[thread overview]
Message-ID: <1301324940.14261.232.camel@gandalf.stny.rr.com> (raw)
In-Reply-To: <4D90A1FE.4000405@zytor.com>

On Mon, 2011-03-28 at 07:58 -0700, H. Peter Anvin wrote:
> On 03/28/2011 07:56 AM, richard -rw- weinberger wrote:
> >>
> >> What the heck is wrong with the idiomatic and non-gcc-extension-using:
> >>
> >>        ((void)0)
> >>
> >> ?
> > 
> > AFAIK you cannot use it within an if-statement.
> > 
> 
> OK, fair enough.

If people hate the ({0;}) so much, we could replace it with:

static inline int _WARN_ON_SMP(void) { return 0; }
#define WARN_ON_SMP(x) _WARN_ON_SMP()

That would pretty much do the same thing.

 o Keeps the parameters from being evaluated, as they may not be defined
   for SMP

 o Can be used as a standalone statement without gcc complaining

 o Can be used within an if condition.

Geeze, I never expected such a fuss over a simple change ;)


-- Steve



  reply	other threads:[~2011-03-28 15:09 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <tip-ccd0d44fad38dc1bb4b26dcc7a30e9f2c3b36870@git.kernel.org>
2011-03-28 14:51 ` H. Peter Anvin
2011-03-28 14:56   ` richard -rw- weinberger
2011-03-28 14:58     ` H. Peter Anvin
2011-03-28 15:09       ` Steven Rostedt [this message]
2011-03-28 18:18         ` Alexey Dobriyan
2011-03-29  7:30           ` Ingo Molnar
     [not found]             ` <8fa65ade-2b9f-4f05-9b52-dfd770326f44@email.android.com>
2011-03-29 14:47               ` Steven Rostedt
2011-03-29 11:36           ` Steven Rostedt

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