Re: [PATCH v2 1/2] memcg: move mem_cgroup_swappiness and vm_swappiness to mm/swap.h

[Barry Song]

On Thu, Jul 16, 2026 at 11:18 AM Ridong <ridong.chen@xxxxxxxxx> wrote:
>
> From: Ridong Chen <chenridong@xxxxxxxxxx>
>
> The per-memcg swappiness knob is v1-only; v2 always uses global
> vm_swappiness and ignores the per-cgroup field.
>
> Both mem_cgroup_swappiness() and vm_swappiness are only used within
> mm/ (memcontrol.c, memcontrol-v1.c, vmscan.c), so move them out of the
> public include/linux/swap.h into the mm-private mm/swap.h. This keeps
> unrelated declarations out of include/linux/swap.h.
>
> Guard memcg->swappiness with CONFIG_MEMCG_V1 as well, so v2-only
> kernels drop the unused field.
>
> No functional change for v1; v2-only kernels drop the unused field.
>
> Signed-off-by: Ridong Chen <chenridong@xxxxxxxxxx>
> ---

Reviewed-by: Barry Song <baohua@xxxxxxxxxx>