Turkeys and dynamic linking

Bill Moran wmoran at potentialtech.com
Fri Nov 28 07:01:20 PST 2003

Michael Edenfield wrote:
> * Kent Stewart <kstewart at owt.com> [031127 17:50]:
>>On Thursday 27 November 2003 12:31 pm, Bill Moran wrote:
>>>walt wrote:
>>>>To all of you who celebrate Thanksgiving today, I wish you a happy one!
>>>>And speaking of turkeys, does anyone know how Microsoft handles the
>>>>performance issues associated with dynamic linking?  Do they do
>>>>anything special, or just ignore the whole thing?
>>>Don't they fix the performance hit by moving performance-critical parts
>>>of the application into kernel space (such as IIS and MSSQL)?
>>>At least, that's what Eric Raymond claims in his latest book.  I don't
>>>think that's an approach I would like to see FreeBSD take.


> As far as moving things into the kernel, I'm not sure what ESR is
> referring to.  It's easy to get code into kernel-space by making it a
> device driver, but AFAIK SQL Server code comes all from normal DLL
> libraries, all in user space.

Looks like I overstated it a bit, from the book:

"While NT will use an MMU, NT versions after 3.5 have the system GUI
wired into the same address space as the privileged kernel for performance
reasons.  Recent versions even wire the webserver into kernel space in an
attempt to match the speed of Unix-based webservers."

Bill Moran
Potential Technologies

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