Re: Delete drivers/pci/syscall.c?

[Linus Torvalds <torvalds@osdl.org>]

On Tue, 19 Oct 2004, Matthew Wilcox wrote:
> 
> Linus, I noticed you touching drivers/pci/syscall.c which made me look
> a bit more carefully at that file.  It is broken for machines with
> overlapping PCI bus numbers in separate domains.  There's basically no
> way to fix this unless we encode the domain into the upper bits of the
> bus number.
> 
> The information is already available through /proc and /sys.  It's hooked
> into the syscall tables of alpha, arm, ia64, ppc, ppc64, sparc and
> sparc64.  Whatever's using those syscalls must have some kind of backup
> strategy for grovelling around in files.

While the system calls may be broken in theory (multiple domains) they are 
not broken in practice (single-domain workstations), and they _were_ used 
by X, at least on alpha last time I looked.

And no, expectign X to have a fallback and to understand multiple domains 
is likely not a valid expectation.

So right now X may work only on single-domain setups, or on setups where 
the video card has a unique address when ignoring the domnain number. 
That's pretty much all of the affected machines, so no, I don't think we 
can/should remove it.

Will X eventually learn about multiple domains? Maybe. 

			Linus