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Date: Thu, 11 May 2006 09:05:44 +1000
From: Paul Mackerras <paulus@samba.org>
To: Richard Henderson <rth@twiddle.net>
Subject: Re: [RFC/PATCH] Make powerpc64 use __thread for per-cpu variables
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Richard Henderson writes:

> How do you plan to address the compiler optimizing
> 
> 	__thread int foo;
> 	{
> 	  use(foo);
> 	  schedule();
> 	  use(foo);
> 	}
> 
> into
> 
> 	{
> 	  int *tmp = &foo;	// tls arithmetic here
> 	  use(*tmp);
> 	  schedule();
> 	  use(*tmp);
> 	}

Hmmm...  Would it be sufficient to use a RELOC_HIDE in __get_cpu_var,
like this?

#define __get_cpu_var(x)	(*(RELOC_HIDE(&per_cpu__##x, 0)))

Paul.