From: Vernon Yang <yanglincheng@kylinos.cn>

When an mm with the MMF_DISABLE_THP_COMPLETELY flag is detected during
scanning, directly set khugepaged_scan.mm_slot to the next mm_slot,
reduce redundant operation.

Without this patch, entering khugepaged_scan_mm_slot() next time, we
will set khugepaged_scan.mm_slot to the next mm_slot.

With this patch, we will directly set khugepaged_scan.mm_slot to the
next mm_slot.

Signed-off-by: Vernon Yang <yanglincheng@kylinos.cn>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
---
 mm/khugepaged.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index be1c09842ea2..1dc19c1b1f97 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -2558,7 +2558,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, enum scan_result
 	 * Release the current mm_slot if this mm is about to die, or
 	 * if we scanned all vmas of this mm.
 	 */
-	if (hpage_collapse_test_exit(mm) || !vma) {
+	if (hpage_collapse_test_exit_or_disable(mm) || !vma) {
 		/*
 		 * Make sure that if mm_users is reaching zero while
 		 * khugepaged runs here, khugepaged_exit will find
-- 
2.51.0

On 23/01/26 1:52 pm, Vernon Yang wrote:
> From: Vernon Yang <yanglincheng@kylinos.cn>
>
> When an mm with the MMF_DISABLE_THP_COMPLETELY flag is detected during
> scanning, directly set khugepaged_scan.mm_slot to the next mm_slot,
> reduce redundant operation.
>
> Without this patch, entering khugepaged_scan_mm_slot() next time, we
> will set khugepaged_scan.mm_slot to the next mm_slot.
>
> With this patch, we will directly set khugepaged_scan.mm_slot to the
> next mm_slot.
>
> Signed-off-by: Vernon Yang <yanglincheng@kylinos.cn>
> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
> Reviewed-by: Lance Yang <lance.yang@linux.dev>
> ---
>  mm/khugepaged.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index be1c09842ea2..1dc19c1b1f97 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -2558,7 +2558,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, enum scan_result
>  	 * Release the current mm_slot if this mm is about to die, or
>  	 * if we scanned all vmas of this mm.
>  	 */

Need to update comment: "...or THP got disabled".

Reviewed-by: Dev Jain <dev.jain@arm.com>

> -	if (hpage_collapse_test_exit(mm) || !vma) {
> +	if (hpage_collapse_test_exit_or_disable(mm) || !vma) {
>  		/*
>  		 * Make sure that if mm_users is reaching zero while
>  		 * khugepaged runs here, khugepaged_exit will find

On Fri, Jan 23, 2026 at 8:40 PM Dev Jain <dev.jain@arm.com> wrote:
>
>
> On 23/01/26 1:52 pm, Vernon Yang wrote:
> > From: Vernon Yang <yanglincheng@kylinos.cn>
> >
> > When an mm with the MMF_DISABLE_THP_COMPLETELY flag is detected during
> > scanning, directly set khugepaged_scan.mm_slot to the next mm_slot,
> > reduce redundant operation.
> >
> > Without this patch, entering khugepaged_scan_mm_slot() next time, we
> > will set khugepaged_scan.mm_slot to the next mm_slot.
> >
> > With this patch, we will directly set khugepaged_scan.mm_slot to the
> > next mm_slot.
> >
> > Signed-off-by: Vernon Yang <yanglincheng@kylinos.cn>
> > Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
> > Reviewed-by: Lance Yang <lance.yang@linux.dev>
> > ---
> >  mm/khugepaged.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> > index be1c09842ea2..1dc19c1b1f97 100644
> > --- a/mm/khugepaged.c
> > +++ b/mm/khugepaged.c
> > @@ -2558,7 +2558,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, enum scan_result
> >        * Release the current mm_slot if this mm is about to die, or
> >        * if we scanned all vmas of this mm.
> >        */
>
> Need to update comment: "...or THP got disabled".
>

+1
With that,
Reviewed-by: Barry Song <baohua@kernel.org>

On Fri, Jan 23, 2026 at 8:40 PM Dev Jain <dev.jain@arm.com> wrote:
>
> On 23/01/26 1:52 pm, Vernon Yang wrote:
> > From: Vernon Yang <yanglincheng@kylinos.cn>
> >
> > When an mm with the MMF_DISABLE_THP_COMPLETELY flag is detected during
> > scanning, directly set khugepaged_scan.mm_slot to the next mm_slot,
> > reduce redundant operation.
> >
> > Without this patch, entering khugepaged_scan_mm_slot() next time, we
> > will set khugepaged_scan.mm_slot to the next mm_slot.
> >
> > With this patch, we will directly set khugepaged_scan.mm_slot to the
> > next mm_slot.
> >
> > Signed-off-by: Vernon Yang <yanglincheng@kylinos.cn>
> > Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
> > Reviewed-by: Lance Yang <lance.yang@linux.dev>
> > ---
> >  mm/khugepaged.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> > index be1c09842ea2..1dc19c1b1f97 100644
> > --- a/mm/khugepaged.c
> > +++ b/mm/khugepaged.c
> > @@ -2558,7 +2558,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, enum scan_result
> >        * Release the current mm_slot if this mm is about to die, or
> >        * if we scanned all vmas of this mm.
> >        */
>
> Need to update comment: "...or THP got disabled".

LGTM, I will update comment in the next version. Thanks!

> Reviewed-by: Dev Jain <dev.jain@arm.com>
>
> > -     if (hpage_collapse_test_exit(mm) || !vma) {
> > +     if (hpage_collapse_test_exit_or_disable(mm) || !vma) {
> >               /*
> >                * Make sure that if mm_users is reaching zero while
> >                * khugepaged runs here, khugepaged_exit will find