linux-kernel - Re: [PATCH] Prevent users from disabling tickless

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Message-ID: <20101222213403.GP1263@parisc-linux.org>
Date:	Wed, 22 Dec 2010 14:34:03 -0700
From:	Matthew Wilcox <matthew@....cx>
To:	Frank Rowand <frank.rowand@...sony.com>
Cc:	Thomas Gleixner <tglx@...utronix.de>,
	Arjan van de Ven <arjan@...radead.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] Prevent users from disabling tickless

On Wed, Dec 22, 2010 at 01:00:37PM -0800, Frank Rowand wrote:
> Why remove the ability to make the configuration choice?  Why not
> just add the info about performance impact to the help text and
> let me shoot myself in the foot (that is the unix way (tm)) if
> I desire to?

$ wc -l .config
2601 .config

It's too hard to get every single config option right ... unless it's a
works / doesn't work choice, having a "make my performance suck" config
option is a bad idea.  I didn't even know I had this config option
set the wrong way until I ran powertop on my desktop, implemented its
recommendations for things I'd screwed up in my .config, then reran the
tests I was doing.

Someone with a big server might not run powertop, so wouldn't be
told they'd got it run.  Sure, we could write a special tool to
check peoples config options to see if they've got some common
config options set wrongly ... but I'm rather reminded of Brazil.
http://farm1.static.flickr.com/50/109556460_5362c5f2b5_o.jpg

-- 
Matthew Wilcox				Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."
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