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Date: Tue, 17 Jul 2007 01:05:12 +0200
From: Rene Herman <rene.herman@gmail.com>
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To: Ray Lee <ray-lk@madrabbit.org>
CC: Alan Cox <alan@lxorguk.ukuu.org.uk>, Bodo Eggert <7eggert@gmx.de>,
       Matt Mackall <mpm@selenic.com>, Jeremy Fitzhardinge <jeremy@goop.org>,
       Jesper Juhl <jesper.juhl@gmail.com>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       William Lee Irwin III <wli@holomorphy.com>, David Chinner <dgc@sgi.com>,
       Arjan van de Ven <arjan@infradead.org>
Subject: Re: [PATCH][RFC] 4K stacks default, not a debug thing any more...?
References: <8FO1e-2jW-35@gated-at.bofh.it> <8GkNo-2Vb-1@gated-at.bofh.it>	 <8GtnN-7TG-23@gated-at.bofh.it> <8GVjY-PL-25@gated-at.bofh.it>	 <E1IA7j1-0000j9-I3@be1.lrz> <469A5D7C.5010904@gmail.com>	 <Pine.LNX.4.58.0707161523500.25779@be1.lrz>	 <469BF104.1040703@gmail.com>	 <2c0942db0707161537o2852a308s26e79235e897e282@mail.gmail.com>	 <20070716235438.1bdd0722@the-village.bc.nu> <2c0942db0707161553u5d55724u82424b3ffbbd79f7@mail.gmail.com>
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On 07/17/2007 12:53 AM, Ray Lee wrote:

> On 7/16/07, Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:

>> Any x86-32 path unsafe with 4K stacks is almost certainly unsafe with 8K
>> stacks because the 8K stacks do not have seperate IRQ stack paths, so you
>> have the same space but split. It might be less predictable on 8K stacks
>> but it isn't absent.
> 
> Understood, but isn't that an argument pro interrupt stacks, rather
> than one against 8k? wli has a patch to break out the interrupt stack
> feature from the 4k/8k choice.

Yes but it's also an argument that the 4K stacks don't make the _current_ 
situation without CONFIG_4KSTACKS selected worse and given that you trust 
that current situation, that leaves you without your argument :-)

Rene.