On Sat, 4 Nov 2000, Stefan Seefeld wrote:
> "Jon M. Taylor" wrote:
> >
> > On Sat, 4 Nov 2000, Stefan Seefeld wrote:
> >
> > Your mail client is wrapping your posts at 84 columns....
> >
> > > In fact, I think video memory management should be at the very core of GGI,
>together
> > > with drawing primitives. Every advanced program will require that.
> >
> > _Resources_ are at the core of GGI. Not every target has video
> > memory to manage. We _should_ write an extension for this, but to do it
> > properly requires a great deal of OS-level code and probably direct
> > integration with the VM subsystems of the OS itself. Seeing as how
> > Linux's method of "managing" the AGP GART pagetable mappings is to expose
> > a /dev/agpgart and use ioctl()s to establish the mappings <vomit>, or that
> > MTRRs are set/read using write()/read() on /proc/mtrr <gag!>, I think
> > we'll be waiting for this until 2.5/2.6 kernels at the earliest.
>
> What do the kernel developers think about that ?
Right now, they are focused on getting 2.4 out the door. The
rawio stuff (kiobufs, kiovecs) that went into 2.3/2.4 is a step in the
right direction - it allows userspace to have much more fine-grained
control over the low-level VM mappings (pagetables, physical-to-virtual
page mappings, page cacheing, etc) of memory mapped files. But I have
not seen any mention of such a comprehensive "page coloring" or "page
tagging" system as I proposed. Lots of driver subsystems could make
their memory-management routines much more generic if such a system was
present....
> Doesn't Alan work on some video
> architecture ?
Alan has worked on the video4linux API in the past - I do not know
if he continues to do so.
> Are they totally satisfied with the current state ?
Linus appears to be happy to let the DRI people deal with this
sort of thing for now. Their system is a _little_ more powerful than
/dev/agpgart (they implement some generic reader/writer locking and
synchronized DMA flushes), but not much.
> Or do they
> assume that there is no life after X ? ;)
It seems that way.
Jon
---
'Cloning and the reprogramming of DNA is the first serious step in
becoming one with God.'
- Scientist G. Richard Seed
