Re: [PATCH mm-unstable v1] mm/truncate: batch-clear shadow entries

[Matthew Wilcox]

On Mon, Jul 08, 2024 at 03:27:53PM -0600, Yu Zhao wrote:
> Make clear_shadow_entry() clear shadow entries in `struct folio_batch`
> so that it can reduce contention on i_lock and i_pages locks, e.g.,

I think it needs to be renamed, perhaps to clear_shadow_entries().

> @@ -503,8 +486,8 @@ unsigned long mapping_try_invalidate(struct address_space *mapping,
>  			/* We rely upon deletion not changing folio->index */
>  
>  			if (xa_is_value(folio)) {
> -				count += invalidate_exceptional_entry(mapping,
> -							     indices[i], folio);
> +				xa_has_values = true;
> +				count++;

Mmm.  This is awkward.  It's supposed to return the number of pages,
not the number of folios (or shadow entries) invalidated.