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Date: Sun, 28 Oct 2007 20:34:14 -0700 (PDT)
From: Christoph Lameter <clameter@sgi.com>
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To: Pekka J Enberg <penberg@cs.helsinki.fi>
cc: Matthew Wilcox <matthew@wil.cx>, akpm@linux-foundation.org,
       linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [patch 08/10] SLUB: Optional fast path using cmpxchg_local
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On Sun, 28 Oct 2007, Pekka J Enberg wrote:

> -	local_irq_restore(flags);
> +	object = do_slab_alloc(s, c, gfpflags, node, addr);
> +	if (unlikely(!object))
> +		goto out;

Undoing the optimization that one of the earlier patches added.

The #ifdef version is for me at least easier to read. The code there is a 
special unit that has to deal with the most performance critical piece of 
the slab allocator. And the #ifdef there clarifies that any changes have 
to be done to both branches.