Re: [PATCH] xfs: Use xarray to track SB UUIDs instead of plain array.

["Darrick J. Wong" <djwong@kernel.org>]

On Mon, Feb 02, 2026 at 09:17:31PM -0800, Christoph Hellwig wrote:
> On Mon, Feb 02, 2026 at 10:50:13AM -0800, Darrick J. Wong wrote:
> > > I do not have strong preference here.
> > 
> > <shrug> Since the original message said "krealloc prints out warning if
> > allocation is bigger than 2x PAGE_SIZE", I figured that meant you were
> > trying to mount more than (2 * 4096) / 16 == 512 different xfs
> > filesystems on the same host.
> 
> I don't remember any such message.  But array or xarray iterations
> should still scale well enough for a single mount time operation into
> the 10.000nds of entries.
> 
> > I don't have a particular problem with the array search and large memory
> > allocation since I never mount that many filesystems, but you would
> > appear to be the first user to complain about a scaling limit there...
> 
> I was really just concerned about a single large allocation.  But yeah,
> it's not that large...  That beind said I think the xarray version will
> also look nicer than the original one.

It's better than the raw kvalloc'd blob we have now :)

--D