> Jon M. Taylor wrote:
> > > The X server is a lot harder to debug than the kernel. Its large, it takes
> > > ages to build and video hardware was mostly designed by people who evidently
> > > then didnt have to program it.
> >
> > Here's even yet still more reasons why the X server is harder to
> > debug video drivers in than the kernel:
>
> The X server is hard to debug
> and the Kernel is not simple to debug.
>
> You want to combine two complex things!
No, and I don't have to. If I put a video driver in the kernel,
that video driver code is all I have to worry about debugging. I won't
have to worry about X debugging at all. Just as I don't have to debug
Midnight Commander if I am writing a SCSI driver.
> What if the resources needed to handle the complexity scales
> exponentially?
Scales with what? Not with number of lines of code - KGI enforces
separation of video driver subsections, so it is much harder for one part
of the driver to stomp on another. Further separation is probable.
Besides, drivers don't tend to do that. They grow until they have enough
code to completely control the hardware, and from then on it is all just
bug fixing and interface optimization.
> You indicate that you've done some work in kernel space with
> graphics cards. What do you think about the combined complexity issue?
It is a nonissue.
> Obviously, money cannot handle the complexity, ask MS :-)
It doesn't have to. Each individual driver is just not that
complex, and that one driver is all I have to worry about at one time. In
fact that part is MUCH easier than with X, because X's drivers are
monolithic and have to care about half a dozen ramdac and clockchip
drivers in addition to the chipset driver. With KGI, I don't even have to
worry about anything but the chipset driver if that is what I am working
on. The clockchip/ramdac/accel/monitor drivers can't stomp on my code,
all they can do is pass me garbage data through the interfaces they use to
communicate. Easy to spot, easy to fix.
Jon
--- 'Cloning and the reprogramming of DNA is the first serious step in becoming one with God.' - Scientist G. Richard Seed
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