Re: [PATCH 2/6] mm/vmscan: use node_is_toptier helper in node_reclaim

From: Jagdish Gediya
Date: Wed May 04 2022 - 03:27:01 EST


On Fri, Apr 15, 2022 at 10:38:58PM -0700, Davidlohr Bueso wrote:
> We have helpers for a reason.
>
> Signed-off-by: Davidlohr Bueso <dave@xxxxxxxxxxxx>
> ---
> mm/vmscan.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 1678802e03e7..cb583fcbf5bf 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -4750,7 +4750,7 @@ int node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned int order)
> * over remote processors and spread off node memory allocations
> * as wide as possible.
> */
> - if (node_state(pgdat->node_id, N_CPU) && pgdat->node_id != numa_node_id())
> + if (node_is_toptier(pgdat->node_id) && pgdat->node_id != numa_node_id())
Currently node_is_toptier returns all N_CPU node as toptier but N_CPU
node will not stay necessarily top tier as per discussions on below
thread.

https://lore.kernel.org/linux-mm/CAAPL-u9sVx94ACSuCVN8V0tKp+AMxiY89cro0japtyB=xNfNBw@xxxxxxxxxxxxxx/

node_is_toptier() definition can change based on the discussion in above
thread.
> return NODE_RECLAIM_NOSCAN;
>
> if (test_and_set_bit(PGDAT_RECLAIM_LOCKED, &pgdat->flags))
> --
> 2.26.2
>
>