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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

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."
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/