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Date: Thu, 1 Aug 2013 12:12:56 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Waiman Long <Waiman.Long@hp.com>, Thomas Gleixner <tglx@linutronix.de>,
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        "Chandramouleeswaran, Aswin" <aswin@hp.com>,
        "Norton, Scott J" <scott.norton@hp.com>
Subject: Re: [PATCH RFC 1/2] qspinlock: Introducing a 4-byte queue spinlock
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On Thu, Aug 01, 2013 at 03:41:33PM +0530, Raghavendra K T wrote:
> It is exactly 16k-1 not 15k
> That is because CPU_CODE of 1 to 16k represents cpu 0..16k-1

>>From what I know big systems are usually build with power-of-two
factors. Although I suppose with a ring fabric you could have an
arbitrary number of nodes.

Anyway, I've heard SGI talk about 4K cpu systems, 8K cpu systems and 16K
cpu systems, I've not heard them talk about 16K-n systems.

Also, as in other parts of the reply I send, this limitation seems
completely unnecessary.