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Date: Sat, 20 Mar 2010 10:47:47 -0700 (PDT)
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Peter Zijlstra <peterz@infradead.org>
cc: "Rafael J. Wysocki" <rjw@sisk.pl>,
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       LKML <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@elte.hu>,
       Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [Regression, post-2.6.34-rc1][PATCH] x86 / perf: Fix suspend to
 RAM on HP nx6325
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On Sat, 20 Mar 2010, Peter Zijlstra wrote:
>  
>  	cpuhw = &per_cpu(cpu_hw_events, cpu);
> +	if (!cpuhw)
> +		return;

How can an address-of expression be NULL?

Yes, 'per_cpu()' is magic, but it shouldn't be possible to be _that_ 
magic. It's rather against the whole C model.

		Linus