Re: kill -9 <pid of X>

Geert Uytterhoeven (Geert.Uytterhoeven@cs.kuleuven.ac.be)
Fri, 14 Aug 1998 01:04:03 +0200 (CEST)


On Thu, 13 Aug 1998, Albert D. Cahalan wrote:
> So why give userspace a framebuffer device at all? The X server will
> need to bang the raw hardware anyway. You could have the kernel code
> just do the /dev/tty* and /dev/vcs* devices, without the useless
> framebuffer ones. Since X needs privilege to access the accelerator
> anyway, it might as well just open /dev/mem.

Sure, let's all mmap /dev/mem and do whatever we want in user space.

> That would be less kernel bloat, even for 680x0 systems with a console!
> Really, the framebuffer devices don't give us anything useful.

That's your opinion.

> > When you want to have accel control in user space, you tell fbdev
> > and it wont use acceleration for the console until the user space
> > program finishes with it.
>
> That isn't safe. You can't expect to access video memory at all
> while the X server is running the accelerator. You may crash the card.
>
> You also need to get into a simple video mode before X starts, so
> that the X server knows the video mode. You can't do that with VESA.
>
> This system just isn't going to cover all PC hardware with full
> acceleration support in userspace. I'm sure it works just great
> on your 680x0 machine, but Linux runs on PC hardware too.

This is one major mistake: we did not say you _have_ to use frame buffer
devices on PC! Let us use them on architectures where we have to because
there's no text mode, or because the boot PROM puts the hardware in graphics
mode anyway. Just keep on using vgacon and be happy.

Vesafb is a hack: it just wasn't difficult to write it, and the simplest way to
get a Penguin on Intel.

Greetings,

Geert

--
Geert Uytterhoeven                     Geert.Uytterhoeven@cs.kuleuven.ac.be
Wavelets, Linux/{m68k~Amiga,PPC~CHRP}  http://www.cs.kuleuven.ac.be/~geert/
Department of Computer Science -- Katholieke Universiteit Leuven -- Belgium

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.altern.org/andrebalsa/doc/lkml-faq.html