Re: [PATCH] mm: memcg: Use larger chunks for proactive reclaim
From: Michal Koutný
Date: Thu Feb 01 2024 - 08:57:39 EST
Hello.
On Wed, Jan 31, 2024 at 04:24:41PM +0000, "T.J. Mercier" <tjmercier@xxxxxxxxxx> wrote:
> reclaimed = try_to_free_mem_cgroup_pages(memcg,
> - min(nr_to_reclaim - nr_reclaimed, SWAP_CLUSTER_MAX),
> + max((nr_to_reclaim - nr_reclaimed) / 4,
> + (nr_to_reclaim - nr_reclaimed) % 4),
The 1/4 factor looks like magic.
Commit 0388536ac291 says:
| In theory, the amount of reclaimed would be in [request, 2 * request).
Doesn't this suggest 1/2 as a better option? (I didn't pursue the
theory.)
Also IMO importantly, when nr_to_reclaim - nr_reclaimed is less than 8,
the formula gives arbitrary (unrelated to delta's magnitude) values.
Regards,
Michal
Attachment:
signature.asc
Description: PGP signature