Re: [PATCH mm-unstable v18 03/14] mm/khugepaged: rework max_ptes_* handling with helper functions

[Zi Yan]

On 22 May 2026, at 10:59, Nico Pache wrote:

> The following cleanup reworks all the max_ptes_* handling into helper
> functions. This increases the code readability and will later be used to
> implement the mTHP handling of these variables.
>
> With these changes we abstract all the madvise_collapse() special casing
> (do not respect the sysctls) away from the functions that utilize them.
> And will be used later in this series to cleanly restrict the mTHP
> collapse behavior.
>
> No functional change is intended; however, we are now only reading the
> sysfs variables once per scan, whereas before these variables were being
> read on each loop iteration.
>
> Reviewed-by: Lance Yang <lance.yang@xxxxxxxxx>
> Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
> Acked-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>
> Acked-by: Usama Arif <usama.arif@xxxxxxxxx>
> Signed-off-by: Nico Pache <npache@xxxxxxxxxx>
> ---
>  mm/khugepaged.c | 120 +++++++++++++++++++++++++++++++++---------------
>  1 file changed, 84 insertions(+), 36 deletions(-)
>

userfaultfd_armed() and cc->is_khugepaged check results are now folded
into collapse_max_ptes_*() return values, using 0 and HPAGE_PMD_NR.
It simplifies the caller code. LGTM.

Reviewed-by: Zi Yan <ziy@xxxxxxxxxx>

Best Regards,
Yan, Zi