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Date: Thu, 03 Mar 2005 17:32:02 -0700
From: Scott Long <scottl@samsco.org>
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To: David Xu <davidxu@freebsd.org>
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cc: David Schultz <das@freebsd.org>
cc: freebsd-arch@freebsd.org
Subject: Re: Removing kernel thread stack swapping
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David Xu wrote:
> Brooks Davis wrote:
> 
>> On Thu, Mar 03, 2005 at 09:54:07AM -0500, John Baldwin wrote:
>>  
>>
>>> Hence, don't kill this whole feature just because someone is too lazy
>>> to fix a bug.
>>>   
>>
>>
>> It would be very useful and informative if someone were to write a
>> high level description of the ways in which the kernel is not a POSIX C
>> programming environment.
> 
> when you are importing a POSIX C programmed piece of code into kernel,
> this will be a problem, I always think problem from another side, not just
> stand at my side. :)

The kernel is not a POSIX C environment.  It's not just a program that
happens to do special things.  I know that Linux goes to great lengths
to support this concept, but it's simply not true.  Programming in the
kernel ideally is not much different from other forms of embedded system
programming where resources are finite and expensive and it's the
responibility of the programmer to develop efficient and safe code.

Scott