From: Andi Kleen <ak@suse.de>
Organization: SUSE Linux Products GmbH, Nuernberg, GF: Markus Rex, HRB 16746 (AG Nuernberg)
To: Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH 00/10] x86: Reduce memory and intra-node effects with large count NR_CPUs
Date: Mon, 14 Jan 2008 11:04:18 +0100
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Cc: travis@sgi.com, Andrew Morton <akpm@linux-foundation.org>,
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> i.e. we've got ~22K bloat per CPU - which is not bad, but because it's a 
> static component, it hurts smaller boxes. For distributors to enable 
> CONFIG_NR_CPU=1024 by default i guess that bloat has to drop below 1-2K 
> per CPU :-/ [that would still mean 1-2MB total bloat but that's much 
> more acceptable than 23MB]

Even 1-2MB overhead would be too much for distributors I think. Ideally
there must be near zero overhead for possible CPUs (and I see no principle
reason why this is not possible) Worst case a low few hundred KBs, but even
that would be much.

There are the cpusets which get passed around, but these are only one bit per 
possible CPU.

-Andi
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