Re: [PATCH v6 2/9] mm/page_owner: add MR_NEVER to enum migrate_reason and use it for last_migrate_reason

[David Hildenbrand (Arm)]

On 7/14/26 03:51, Ye Liu wrote:
> The last_migrate_reason field uses -1 as a sentinel value to mean "no
> migration has happened".  Replace the four bare -1 occurrences by
> adding a proper MR_NEVER member to enum migrate_reason, defining a
> corresponding "never_migrated" string in the MIGRATE_REASON trace
> macro, and updating the GDB page_owner script to use MR_NEVER instead
> of the hardcoded -1 so that lx-dump-page-owner does not incorrectly
> report unmigrated pages as migrated.
> 
> No functional change.
> 
> Signed-off-by: Ye Liu <ye.liu@xxxxxxxxx>
> Reviewed-by: Zi Yan <ziy@xxxxxxxxxx>
> Reviewed-by: Vlastimil Babka (SUSE) <vbabka@xxxxxxxxxx>
> ---
>  include/linux/migrate_mode.h    | 1 +
>  include/trace/events/migrate.h  | 3 ++-
>  mm/page_owner.c                 | 8 ++++----
>  scripts/gdb/linux/page_owner.py | 4 +++-
>  4 files changed, 10 insertions(+), 6 deletions(-)
> 
> diff --git a/include/linux/migrate_mode.h b/include/linux/migrate_mode.h
> index 265c4328b36a..05102d4d2490 100644
> --- a/include/linux/migrate_mode.h
> +++ b/include/linux/migrate_mode.h
> @@ -25,6 +25,7 @@ enum migrate_reason {
>  	MR_LONGTERM_PIN,
>  	MR_DEMOTION,
>  	MR_DAMON,
> +	MR_NEVER,		/* page has never been migrated */

Shouldn't this be more like

"MR_NONE" ?

As "never" is not really a "reason" ?

-- 
Cheers,

David