Re: [PATCH 1/5] xfs: create separate structures and code for u32 bitmaps

Darrick J. Wong
2023-11-28T01:34:45Z

On Fri, Nov 24, 2023 at 09:57:35PM -0800, Christoph Hellwig wrote:
> On Fri, Nov 24, 2023 at 03:50:02PM -0800, Darrick J. Wong wrote:
> > Create a version of the xbitmap that handles 32-bit integer intervals
> > and adapt the xfs_agblock_t bitmap to use it. This reduces the size of
> > the interval tree nodes from 48 to 36 bytes and enables us to use a more
> > efficient slab (:0000040 instead of :0000048) which allows us to pack
> > more nodes into a single slab page (102 vs 85).
>
> The changes themsleves looks good:
>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
>
> Q: should we rename the existing xbitmap to xbitmap64 for consistency?

Yes. Done.

> Also why are the agb_bitmap* wrappers in bitmap.h? Following our
> usual code organization I'd expect bitmap.[ch] to just be the
> library code and have users outside of that. Maybe for later..

Those wrappers are trivial except for the enhanced typechecking, so I
didn't think it was a big deal to cram them into bitmap.h.

--D