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Date: Wed, 18 Jul 2007 15:48:11 +0200
From: Ingo Molnar <mingo@elte.hu>
To: Roman Zippel <zippel@linux-m68k.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
       Linus Torvalds <torvalds@linux-foundation.org>,
       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
Message-ID: <20070718134811.GA9227@elte.hu>
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* Roman Zippel <zippel@linux-m68k.org> wrote:

> > By breaking the UNIX model of nice levels. Not an option in my book.
> 
> Breaking user expectations of nice levels is?

_changing_ it is an option within reason, and we've done it a couple of 
times already in the past, and even within CFS (as Peter correctly 
observed) we've been through a couple of iterations already. And as i 
mentioned it before, the outer edge of nice levels (+19, by far the most 
commonly used nice level) was inconsistent to begin with: 3%, 5%, 9% of 
nice-0, depending on HZ. So changing that to a consistent (and 
user-requested) 1.5% is a much smaller change than you seem to make it 
out to be. CFS itself is a far larger "change of expectations" than this 
tweak to nice levels. So by your standard we could never change the 
scheduler. (which your ultimate argument might be after all =B-)

	Ingo