Re: [PATCH v2 6/6] alloc_tag: config to store page allocation tag refs in page flags

[Matthew Wilcox]

On Tue, Sep 03, 2024 at 06:25:52PM -0700, John Hubbard wrote:
> The more I read this story, the clearer it becomes that this should be
> entirely done by the build system: set it, or don't set it, automatically.
> 
> And if you can make it not even a kconfig item at all, that's probably even
> better.
> 
> And if there is no way to set it automatically, then that probably means
> that the feature is still too raw to unleash upon the world.

I'd suggest that this implementation is just too whack.

What if you use a maple tree for this?  For each allocation range, you
can store a pointer to a tag instead of storing an index in each folio.