Re: [PATCH v6 12/19] selftests/mm: parameterize the mixed-source collapse case by source order

[Baolin Wang]

On 9/19/26 8:24 AM, Kiryl Shutsemau wrote:
> From: "Kiryl Shutsemau (Meta)" <kas@xxxxxxxxxx>
>
> collapse_order_mixed_sources() faults its region as order-2 folios and
> collapses them to the -c target.  Order 2 is below the contpte size on
> every arm64 page size, so nothing in this suite collapses a contpte-mapped
> source on purpose.
>
> Let -s name the source order alongside -c.  The case then faults at that
> order, keeping order 2 when -s is absent, and the source order has to be a
> supported mTHP order below the target.  The other mTHP cases are
> unaffected: mthp_push_target_order() enables only the target order.
>
> A -c at or below -s is refused before any case runs: the sources would
> already be the size being asked for.  Without the check the generic cases
> fail on that one by one instead of saying why.
>
> "-s 5 -c 7" on arm64/64K then collapses contpte-mapped sources into a
> larger mTHP.
>
> Assisted-by: LLM
> Acked-by: Lorenzo Stoakes (ARM) <ljs@xxxxxxxxxx>
> Tested-by: Muhammad Usama Anjum <usama.anjum@xxxxxxx>
> Signed-off-by: Kiryl Shutsemau (Meta) <kas@xxxxxxxxxx>
> ---

LGTM.
Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Tested-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>