Re: [PATCH v4 01/16] mm: thp: Batch-collapse PMD with set_ptes()

[David Hildenbrand]

On 18.12.23 11:50, Ryan Roberts wrote:
> Refactor __split_huge_pmd_locked() so that a present PMD can be
> collapsed to PTEs in a single batch using set_ptes(). It also provides a
> future opportunity to batch-add the folio to the rmap using David's new
> batched rmap APIs.

I'd drop that sentence and rather just say "In the future, we might get 
rid of the remaining manual loop by using rmap batching.".

> This should improve performance a little bit, but the real motivation is
> to remove the need for the arm64 backend to have to fold the contpte
> entries. Instead, since the ptes are set as a batch, the contpte blocks
> can be initially set up pre-folded (once the arm64 contpte support is
> added in the next few patches). This leads to noticeable performance
> improvement during split.
Acked-by: David Hildenbrand <david@xxxxxxxxxx>

--
Cheers,

David / dhildenb