Re: [RESEND PATCH 4.0-rc5 v19 5/6] x86/nmi: Use common printk functions

From: Borislav Petkov <bp@alien8.de>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Jason Cooper <jason@lakedaemon.net>,
	Russell King <linux@arm.linux.org.uk>,
	Will Deacon <will.deacon@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Stephen Boyd <sboyd@codeaurora.org>,
	John Stultz <john.stultz@linaro.org>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, patches@linaro.org,
	linaro-kernel@lists.linaro.org,
	Sumit Semwal <sumit.semwal@linaro.org>,
	Dirk Behme <dirk.behme@de.bosch.com>,
	Daniel Drake <drake@endlessm.com>,
	Dmitry Pervushin <dpervushin@gmail.com>,
	Tim Sander <tim@krieglstein.org>,
	"H. Peter Anvin" <hpa@zytor.com>,
	x86@kernel.org
Subject: Re: [RESEND PATCH 4.0-rc5 v19 5/6] x86/nmi: Use common printk functions
Date: Tue, 7 Apr 2015 18:37:46 +0200	[thread overview]
Message-ID: <20150407163746.GA14115@pd.tnic> (raw)
In-Reply-To: <20150407121942.627d2165@gandalf.local.home>

On Tue, Apr 07, 2015 at 12:19:42PM -0400, Steven Rostedt wrote:
> Not sure what the others think, but I hate this polish notation for
> compares. One does not say "if zero does not equal
> printk_nmi_backtrace_prepare()", they say "if
> printk_nmi_backtrace_prepare() does not return zero".
> 
> And the reason for polish notation is to prevent the:
> 
> 	if (x = 0)
> 
> mistake. Which gcc warns about anyway. Also, this doesn't even pertain
> to this code because:
> 
> 	if (printk_nmi_backtrace_prepare() = 0)
> 
> would fail to compile.

I would simply say:

	err = printk_nmi_backtrace_prepare();
	if (err)

like sane kernel code does.

Besides, there's not a lot of such comparisons in the kernel anyway:

$ git grep -E "if\s+\(+[0-9]+\!?=.*"
drivers/ide/au1xxx-ide.c:246:                   if (1==i)

but my regex doesn't cover all possible variants, just the single-line
ones.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--