Date: Tue, 7 Dec 2010 08:39:06 -0600 (CST)
From: Christoph Lameter <cl@linux.com>
To: Balbir Singh <balbir@linux.vnet.ibm.com>
cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>, akpm@linux-foundation.org,
        Pekka Enberg <penberg@cs.helsinki.fi>, linux-kernel@vger.kernel.org,
        Eric Dumazet <eric.dumazet@gmail.com>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Tejun Heo <tj@kernel.org>, linux-mm@kvack.org
Subject: Re: [thisops uV3 08/18] Taskstats: Use this_cpu_ops
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On Mon, 6 Dec 2010, Balbir Singh wrote:

> > Correct. We need to subtract one from that (which will eliminate the minus
> > -1 that the inline this_cpu_inc_return creates).
> >
>
> But that breaks current behaviour, we should probably initialize all
> of the array to -1?

Not necessary. This_cpu_inc() uses an xadd instruction which retrieves
the value and then increments the memory location. Then it adds 1. The -1
eliminates that add.
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