Re: [PATCH] mm/vmpressure: remove window size TODO

[Vlastimil Babka (SUSE)]

On 8/31/26 15:42, Lorenzo Stoakes (ARM) wrote:
> There has been a steady stream of patches that have been submitted by
> newcomers to core mm 'fixing' this TODO, with all but the original having
> very likely been generated by LLMs.
> 
> It appears that TODOs to LLMs are like red rags to a bull.
> 
> In addition, TODOs in code often bitrot and are distracting - those who
> understand the code know what could be improved in future.
> 
> Therefore remove the TODO.
> 
> The work required to actually fix this TODO requires somebody who both has
> understanding of the code and significant real-world data to back their
> changes.
> 
> Such a person doesn't require a TODO prompt to implement this change, so
> nothing of value is being lost here.
> 
> Link: https://lore.kernel.org/all/20260831130316.448-1-tahasezer.is@xxxxxxxxx/
> Link: https://lore.kernel.org/linux-mm/20260724054305.516126-1-cui.tao@xxxxxxxxx/
> Link: https://lore.kernel.org/linux-mm/20260715143646.15828-1-gaikwad.dcg@xxxxxxxxx/
> Link: https://lore.kernel.org/all/20260227221555.29969-1-mcq@xxxxxxxxxxx/
> Signed-off-by: Lorenzo Stoakes (ARM) <ljs@xxxxxxxxxx>

Acked-by: Vlastimil Babka (SUSE) <vbabka@xxxxxxxxxx>

> ---
>  mm/vmpressure.c | 3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/mm/vmpressure.c b/mm/vmpressure.c
> index 9629240d77ad..3de99fef3928 100644
> --- a/mm/vmpressure.c
> +++ b/mm/vmpressure.c
> @@ -30,9 +30,6 @@
>   *
>   * As the vmscan reclaimer logic works with chunks which are multiple of
>   * SWAP_CLUSTER_MAX, it makes sense to use it for the window size as well.
> - *
> - * TODO: Make the window size depend on machine size, as we do for vmstat
> - * thresholds. Currently we set it to 512 pages (2MB for 4KB pages).
>   */
>  const unsigned long vmpressure_win = SWAP_CLUSTER_MAX * 16;
>  
> 
> ---
> base-commit: cee9395acd8043be0644b25c34bfa86623f2b935
> change-id: 20260831-remove-vmpressure-todo-2d764f42059a
> 
> Cheers,