Re: [RFC][PATCH] ensure i_ino uniqueness in filesystems without permanent inode numbers (via pointer conversion)

[Jeff Layton <jlayton@redhat.com>]

On Fri, 2006-11-17 at 09:21 -0500, Jeff Layton wrote:

> Because the lower 8-9 bits of the inode pointer aren't significant
> (presuming an inode struct size of ~400-800 bytes). If we take those out
> of the picture then we extend the range of addresses that we can
> uniquely squish into a 32 bit value.
> 
> Of course, all of this depends on the idea that the slab allocator grabs
> pages that are somewhat close together in the kernel's address space.
> I'm trying to figure out whether that is the case or not...

It sounds like we can't count on that though. A NUMA system will
apparently map pages *anywhere* within the entire 64-bit address range.
If that's the case, we can't count on the addresses being close enough
together to make this work.

Bummer, I really liked this scheme :-). I suppose I'll have to look at
other options...

-- Jeff