Re: [PATCH 2/4] xfs: add debug knobs to control btree bulk load slack factors

Darrick J. Wong
2023-11-28T01:44:38Z

On Fri, Nov 24, 2023 at 09:50:23PM -0800, Christoph Hellwig wrote:
> On Fri, Nov 24, 2023 at 03:49:15PM -0800, Darrick J. Wong wrote:
> > From: Darrick J. Wong <djwong@kernel.org>
> >
> > Add some debug knobs so that we can control the leaf and node block
> > slack when rebuilding btrees.
>
> Maybe expand a bit on what these "debug knows" are useful for and how
> they work?

They're not generally useful for users, obviously. For developers, it
might be useful to construct btrees of various heights by crafting a
filesystem with a certain number of records and then using repair+knobs
to rebuild the index with a certain shape.

Practically speaking, you'd only ever do that for extreme stress
testing.

--D