Re: [PATCH 05/30] mm/rmap: update mm/interval_tree.c comments

On Mon, Jun 29, 2026 at 12:01:02PM -0400, Gregory Price wrote:
> On Mon, Jun 29, 2026 at 01:23:16PM +0100, Lorenzo Stoakes wrote:
> > Update the file comment to clarify that both file-backed and anonymous
> > interval trees are provided, referencing the relevant data types for
> > clarity.
> >
>
> Isn't this self-evident by nature of the function definitions?
> (one takes a vm_area_struct, the other takes an anon_vma_chain)

Well you see you're already hitting up on issues there, they both take an
rb_root_cached and the vma_*() ones do not instantly scream 'file-backed' do
they? As VMAs are obviously used for buth anon and file-backed...

But later patches fix this stuff :)

And I feel it's hard visually to see where one set of definitions end and
another begins, which was really the motive for this, as trivial as it is!

>
> > -	VM_BUG_ON_VMA(vma_start_pgoff(node) != vma_start_pgoff(prev), node);
> > +	VM_WARN_ON_ONCE_VMA(vma_start_pgoff(node) != vma_start_pgoff(prev), node);
> >
>
> For my own edification - I know not to add new BUG(), should I be
> converting BUG->WARN/something when i find them in areas i happen to be
> working in?

Yeah pretty much in all cases.

It's very rare that you'd want the kernel to definitely oops, and I can't think
of any circumstance where you'd only what that if CONFIG_DEBUG_VM was set :))

>
> ~Gregory

Cheers, Lorenzo