Re: [PATCH v2 2/2] mm/debug: sync up latest migrate_reason to migrate_reason_names

[Huang, Ying]

Weizhao Ouyang <o451686892@xxxxxxxxx> writes:

> Sync up MR_DEMOTION to migrate_reason_names and add a synch prompt.
>
> Fixes: 26aa2d199d6f ("mm/migrate: demote pages during reclaim")
> Signed-off-by: Weizhao Ouyang <o451686892@xxxxxxxxx>
> Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
> ---
>  include/linux/migrate.h | 6 +++++-
>  mm/debug.c              | 1 +
>  2 files changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/migrate.h b/include/linux/migrate.h
> index 326250996b4e..c8077e936691 100644
> --- a/include/linux/migrate.h
> +++ b/include/linux/migrate.h
> @@ -19,6 +19,11 @@ struct migration_target_control;
>   */
>  #define MIGRATEPAGE_SUCCESS		0
>  
> +/*
> + * Keep sync with:
> + * - macro MIGRATE_REASON in include/trace/events/migrate.h
> + * - migrate_reason_names[MR_TYPES] in mm/debug.c
> + */
>  enum migrate_reason {
>  	MR_COMPACTION,
>  	MR_MEMORY_FAILURE,
> @@ -32,7 +37,6 @@ enum migrate_reason {
>  	MR_TYPES
>  };
>  
> -/* In mm/debug.c; also keep sync with include/trace/events/migrate.h */
>  extern const char *migrate_reason_names[MR_TYPES];
>  
>  #ifdef CONFIG_MIGRATION
> diff --git a/mm/debug.c b/mm/debug.c
> index e61037cded98..fae0f81ad831 100644
> --- a/mm/debug.c
> +++ b/mm/debug.c
> @@ -26,6 +26,7 @@ const char *migrate_reason_names[MR_TYPES] = {
>  	"numa_misplaced",
>  	"contig_range",
>  	"longterm_pin",
> +	"demotion",
>  };
>  
>  const struct trace_print_flags pageflag_names[] = {

Can we add BUILD_BUG_ON() somewhere to capture at least some
synchronization issue?

Best Regards,
Huang, Ying