Re: [RFC PATCH v5 3/4] mm/vmscan: avoid pointless large folio splits without swap

[Baolin Wang]

On 7/30/26 8:23 PM, Xueyuan Chen wrote:
> From: "Barry Song (Xiaomi)" <baohua@xxxxxxxxxx>
>
> When swap is disabled, exhausted, or unavailable due to memcg swap
> limits, splitting a large anonymous folio cannot make swapout progress.
> The fallback only destroys the large folio and inflates split statistics.
>
> Use -E2BIG from folio_alloc_swap() as the explicit signal that splitting
> the folio might allow swapout of smaller pieces. For other allocation
> failures, keep the existing activation path and avoid the split.
>
> This preserves the split fallback for fragmented or partially available
> swap, while avoiding it when there is no backing space for any part of the
> folio.
>
> Reported-by: Nanzhe Zhao <zhaonanzhe@xxxxxxxxxx>
> Signed-off-by: Barry Song (Xiaomi) <baohua@xxxxxxxxxx>
> Signed-off-by: Xueyuan Chen <xueyuan.chen21@xxxxxxxxx>
> ---

LGTM. Feel free to add:
Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>