On Mon, 22 Sep 2003, Jon Smirl wrote:

We have to do something about the ioremap of large framebuffers in 2.6. Right
now in 2.6, if you have 1GB or more RAM most framebuffers will fail to load.
With the price of memory falling 1GB will become common during the life of 2.6.

The failure is caused by the individual framebuffer drivers ioremap'ing the
framebuffer into kernel address space. With 1GB memory or more it is almost a
certainty that there is not enough kernel address space available.  Even my
16MB cards fail to load.

What's the maximum amount of address space you can remap? If even 16 MiB fails,
there's a serious problem, not only for fbdev, since you can easily imagine
some other hardware/application that needs to ioremap() 16 MiB.

To me it sounds more like a problem to be solved in the ia32-specific mm-code,
since it's caused by ia32-limitations and mm-decisions in the ia32-specific
code.

Yes, the 32-bit era is (finally) almost over!

BTW, as a comparison: on m68k we could easily have a 4Gi/4Gi kernel/user split
if we ever want that, since unlikely ia32, m68k has moves (move from/to address
space) to access the user address space from kernel space.

Gr{oetje,eeting}s,

						Geert (elitist m68k hacker ;-)

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds



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