Re: [PATCH mm-unstable v15 12/13] mm/khugepaged: run khugepaged for all orders

From: Usama Arif

Date: Thu Feb 26 2026 - 11:03:07 EST


On Wed, 25 Feb 2026 20:26:50 -0700 Nico Pache <npache@xxxxxxxxxx> wrote:

> From: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
>
> If any order (m)THP is enabled we should allow running khugepaged to
> attempt scanning and collapsing mTHPs. In order for khugepaged to operate
> when only mTHP sizes are specified in sysfs, we must modify the predicate
> function that determines whether it ought to run to do so.
>
> This function is currently called hugepage_pmd_enabled(), this patch
> renames it to hugepage_enabled() and updates the logic to check to
> determine whether any valid orders may exist which would justify
> khugepaged running.
>
> We must also update collapse_allowable_orders() to check all orders if
> the vma is anonymous and the collapse is khugepaged.
>
> After this patch khugepaged mTHP collapse is fully enabled.
>
> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Nico Pache <npache@xxxxxxxxxx>
> ---
> mm/khugepaged.c | 30 ++++++++++++++++++------------
> 1 file changed, 18 insertions(+), 12 deletions(-)
>

Acked-by: Usama Arif <usama.arif@xxxxxxxxx>