Re: [RFC PATCH v2 1/2] mm/mempolicy: Expose get_il_weight() to MM

From: Huang, Ying
Date: Tue Jun 24 2025 - 06:58:19 EST


Bijan Tabatabai <bijan311@xxxxxxxxx> writes:

> From: Bijan Tabatabai <bijantabatab@xxxxxxxxxx>
>
> This patch exposes get_il_weight() in mm/internal.h. This patch is to
> allow other parts of the MM subsystem, such as DAMON, to make page
> placement decisions based on the global interleave weights.
>
> Signed-off-by: Bijan Tabatabai <bijantabatab@xxxxxxxxxx>
> ---
> mm/internal.h | 6 ++++++
> mm/mempolicy.c | 2 +-
> 2 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/mm/internal.h b/mm/internal.h
> index 3823fb356d3b..b718ebe7cad5 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -1169,6 +1169,7 @@ extern int node_reclaim_mode;
>
> extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
> extern int find_next_best_node(int node, nodemask_t *used_node_mask);
> +extern u8 get_il_weight(int node);
> #else
> #define node_reclaim_mode 0
>
> @@ -1181,6 +1182,11 @@ static inline int find_next_best_node(int node, nodemask_t *used_node_mask)
> {
> return NUMA_NO_NODE;
> }
> +
> +static inline u8 get_il_weight(int node)
> +{
> + return 1;
> +}
> #endif
>
> static inline bool node_reclaim_enabled(void)
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 1ff7b2174eb7..b1713430ee9c 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -165,7 +165,7 @@ static unsigned int *node_bw_table;
> */
> static DEFINE_MUTEX(wi_state_lock);
>
> -static u8 get_il_weight(int node)
> +u8 get_il_weight(int node)
> {
> struct weighted_interleave_state *state;
> u8 weight = 1;

I agree with David on the function naming and "extern". Otherwise, this
looks good to me, Thanks! Feel free to add my

Reviewed-by: Huang Ying <ying.huang@xxxxxxxxxxxxxxxxx>

in the future versions.

---
Best Regards,
Huang, Ying