Re: [PATCH v5 14/19] selftests/mm: run every supported collapse order by default

[Baolin Wang]

On 9/8/26 8:51 PM, Kiryl Shutsemau wrote:
> From: "Kiryl Shutsemau (Meta)" <kas@xxxxxxxxxx>
>
> The mTHP collapse cases only run when the caller names both the context
> and an order, so a plain ./khugepaged covers the PMD contexts on anon and
> nothing else.  run_vmtests.sh pinned order 4 and covered no other.
>
> Run the mTHP cases once per supported anon THP order below the PMD when
> -c is absent, and pull that context into both the no-argument invocation
> and "all".  Also:
>
>    - -c still pins one order, and now says what is wrong instead of
>      printing the usage text.  An order at or below the -s source order is
>      skipped: the sources would already be the size being asked for.
>
>    - Both orders end up as array indices and shift counts, so -s and -c
>      are range-checked before they get there.
>
>    - The mTHP context has only anon cases, so a run that names a different
>      mem_type -- "all:shmem", say -- drops it again rather than refusing
>      to start.  Naming both explicitly still refuses.
>
>    - A case carries the order it was registered at, so a result names it:
>
>        # Run test: collapse_single_mthp (mthp_khugepaged:anon, order 6)
>
> On x86-64 with 4K pages that is orders 2 through 8, and ./khugepaged goes
> from 29 results in 17 seconds to 77 in 29, so run_vmtests.sh can drop its
> pinned order-4 line.
>
> Assisted-by: LLM
> 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>