Re: [PATCH mm-unstable v18 11/14] mm/khugepaged: Introduce mTHP collapse support

[David Hildenbrand (Arm)]

>  next_order:
> -		if ((BIT(order) - 1) & enabled_orders) {
> -			const u8 next_order = order - 1;
> -			const u16 mid_offset = offset + (nr_ptes / 2);
> -
> -			collapse_mthp_stack_push(cc, &stack_size, mid_offset,
> -						 next_order);
> -			collapse_mthp_stack_push(cc, &stack_size, offset,
> -						 next_order);
> +		if (order > KHUGEPAGED_MIN_MTHP_ORDER &&
> +			(BIT(order) - 1) & enabled_orders) {

Why not a test_bit() ?


But, wouldn't you want to skip orders that are not enabled and try with the next
smaller one in any case before you advance the offset?

-- 
Cheers,

David