From: Jos Hulzink <josh@stack.nl>
To: Linus Torvalds <torvalds@osdl.org>,
       Bradley Chapman <kakadu_croc@yahoo.com>
Subject: Re: What exactly are the issues with 2.6.0-test10 preempt?
Date: Tue, 25 Nov 2003 07:55:07 +0000
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On Monday 24 Nov 2003 22:32, Linus Torvalds wrote:
> Basically, there's something strange going on, which _seems_ to be memory
> corruption, and seems to correlate reasonable well (but not 100%) with
> CONFIG_PREEMPT.
>
> It's actually unlikely to be preemption itself that is broken: it's much
> more likely that some driver or other subsystem is broken, and preempt is
> just better at triggering it by making some race conditions much easier to
> see due to bigger windows for them to happen.
>
> The problem is finding enough of a pattern to the reports to make sense of
> what seems to be the common thread. A lot of people use preemption without
> any trouble.

Maybe brute force is the best way to deal with this nasty one ? I'm thinking: 
It must be rather easy to make a tool that takes a .config file and an 
argument "This kernel seems in trouble Yes / No". If an option is enabled, 
and this kernel config crashes, you increase the likelihood of that option 
(i.e. you increment a counter). If an option is enabled, and this kernel 
doesn't crash. you decrement a counter. In the end, you'll end with 
statistics about which kernel option is likely to cause problems.

Jos

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