Re: Re: Re: [PATCH] mm: memcg: Use larger chunks for proactive reclaim

From: Michal Koutný
Date: Fri Feb 02 2024 - 14:47:09 EST


On Fri, Feb 02, 2024 at 10:22:34AM -0800, "T.J. Mercier" <tjmercier@xxxxxxxxxx> wrote:
> So all of these should be more or less equivalent:
> delta <= SWAP_CLUSTER_MAX ? delta : (delta + 3*SWAP_CLUSTER_MAX) / 4
> max((nr_to_reclaim - nr_reclaimed) / 4, (nr_to_reclaim - nr_reclaimed) % 4)
> (nr_to_reclaim - nr_reclaimed) / 4 + 4
> (nr_to_reclaim - nr_reclaimed) / 4
>
> I was just trying to avoid putting in a 0 for the request size with the mod.

The third variant would be simpler then. Modulo looks weird.

Oh, and I just realized that try_to_free_mem_cgroup_pages() does
max(nr_pages, SWAP_CLUSTER_MAX). Then I'd vote for the fourth variant +
possible comment about harmless 0.
(I'm sorry if this was discussed before.)

Michal

Attachment: signature.asc
Description: PGP signature