Date: Tue, 23 Nov 2010 21:13:33 -0600 (CST)
From: Christoph Lameter <cl@linux.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
cc: akpm@linux-foundation.org, Pekka Enberg <penberg@cs.helsinki.fi>,
        Ingo Molnar <mingo@elte.hu>, Peter Zijlstra <peterz@infradead.org>,
        linux-kernel@vger.kernel.org,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Tejun Heo <tj@kernel.org>
Subject: Re: [thiscpuops upgrade 10/10] Lockless (and preemptless) fastpaths
 for slub
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On Wed, 24 Nov 2010, Eric Dumazet wrote:

> Hmm, this only works for power of two NR_CPUS, or else one cpu 'tid'
> could wrap on another cpu tid.

Hmm... That essentially like using a bitfield then.

> I suggest using 4096  (or roundup_pow_of_two(CONFIG_NR_CPUS))

There could be machines with 64k cpus soon. So I guess roundupp2 it will
have to be.


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