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Date: Mon, 16 Jul 2007 20:12:53 +0200 (CEST)
From: Roman Zippel <zippel@linux-m68k.org>
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To: Linus Torvalds <torvalds@linux-foundation.org>
cc: Ingo Molnar <mingo@elte.hu>, James Bruce <bruce@andrew.cmu.edu>,
       Thomas Gleixner <tglx@linutronix.de>, Mike Galbraith <efault@gmx.de>,
       Andrea Arcangeli <andrea@suse.de>, Andi Kleen <andi@firstfloor.org>,
       Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org,
       Arjan van de Ven <arjan@infradead.org>,
       Chris Wright <chrisw@sous-sol.org>
Subject: Re: [PATCH] CFS: Fix missing digit off in wmult table
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Hi,

On Mon, 16 Jul 2007, Linus Torvalds wrote:

> How about trying a much less aggressive nice-level (and preferably linear, 
> not exponential)?

I think the exponential increase isn't the problem. The old code did 
approximate something like this rather crudely with the result that there 
was a big gap between level 0 and -1.

Something like this:

echo 'for (i=-20;i<=20;i++) print i, " : ", 1024*e(l(2)*(-i/20*3)), "\n";' | bc -l

would produce a range similiar to the old code. Replacing the factor 3 
with 4 would be IMO a more reasonable increase and had the advantage for 
the user that it's easier to understand that every 5 levels the time a 
process gets is doubled.

bye, Roman