Re: [RFC PATCH v2 12/47] hugetlb: add hugetlb_hgm_walk and hugetlb_walk_step

[James Houghton]

On Wed, Nov 16, 2022 at 2:02 PM Peter Xu <peterx@xxxxxxxxxx> wrote:
>
> On Fri, Oct 21, 2022 at 04:36:28PM +0000, James Houghton wrote:
> > +/* hugetlb_hgm_walk - walks a high-granularity HugeTLB page table to resolve
> > + * the page table entry for @addr.
> > + *
> > + * @hpte must always be pointing at an hstate-level PTE (or deeper).
> > + *
> > + * This function will never walk further if it encounters a PTE of a size
> > + * less than or equal to @sz.
> > + *
> > + * @stop_at_none determines what we do when we encounter an empty PTE.
>
> IIUC it is not about empty PTE but swap-or-empty pte?
>
> I'm not sure whether it'll be more straightforward to have "bool alloc"
> just to show whether the caller would like to allocate pgtables when
> walking the sub-level pgtable until the level specified.

I think "bool alloc" is cleaner. I'll do that. Thanks for the suggestion.

>
> In final version of the code I also think we should drop all the "/*
> stop_at_pte */" comments in the callers. Maybe that already means the
> meaning of the bool is confusing so we always need a hint.

I did that to hopefully make things easier to read. I'll remove it.

- James

>
> --
> Peter Xu
>