On Mon, Apr 14, 2003 at 11:00:27AM -0700, Linus Torvalds wrote:
> Well, the thing is, we absolutely _do_ need to have the 8+8 split, in
> order to make old devices look the same old way for old binaries.
Yes, and I support this 100%.
> The 16+16 split is not strictly necessary, but Andries pointed out to me
> that there are filesystems etc external storage that only support a 32-bit
> opaque dev_t, so we'd need to marshall the device number _some_ way for
> them anyway, and having a standard way to do that is better than having
> everybody come up with their own variations.
Sure, but it's a marshall, not a reality. One of the reasons
for choosing 64bits is that we can have large spaces for large things.
If a driver happens to get a number in the 16:16 space (or the 12:20
space, which I prefer as well), then it could run out of space and end
up with the multiple major problem.
True, a truly dynamic scheme could make all of this irrelevant,
but I was just postulating that complexity isn't strictly necessary.
I guess it is a trade off. Do all devices greater than 8:8
become 32:32 and merely are masked to 16:16 on limited filesystems, or
do all devices smaller than 16:16/12:20 appear the same on all
filesystems, limited or not?
JOel
--"You can get more with a kind word and a gun than you can with a kind word alone." - Al Capone
Joel Becker Senior Member of Technical Staff Oracle Corporation E-mail: joel.becker@oracle.com Phone: (650) 506-8127 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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