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Date: Wed, 5 Aug 2015 17:35:07 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>, linux-kernel@vger.kernel.org,
        adrian.hunter@intel.com, Arnaldo Carvalho de Melo <acme@infradead.org>,
        Vince Weaver <vince@deater.net>, Stephane Eranian <eranian@google.com>
Subject: Re: [PATCH RFC v1 1/4] perf: Introduce extended syscall error
 reporting
Message-ID: <20150805153507.GM19282@twins.programming.kicks-ass.net>
References: <1437738359-23920-1-git-send-email-alexander.shishkin@linux.intel.com>
 <1437738359-23920-2-git-send-email-alexander.shishkin@linux.intel.com>
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On Fri, Jul 24, 2015 at 02:45:56PM +0300, Alexander Shishkin wrote:
> +#define __perf_err(__e, __c, __m) ({				\
> +	static struct perf_err_site				\
> +	__attribute__ ((unused,__section__("__perf_err")))	\
> +	__err_site = {						\
> +		.message	= (__m),			\
> +		.owner		= PERF_MODNAME,			\
> +		.code		= __builtin_constant_p((__c)) ?	\
> +		(__c) : 0,					\
> +	};							\
> +	(__e) = &__err_site;					\
> +})

Why is __e an argument at all? Why not simply return &__err_site ?