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From: "T.J. Mercier" <tjmercier@google.com>
Date: Fri, 2 Feb 2024 13:42:46 -0800
Message-ID: <CABdmKX3Be=AHSvHOa7NQVapb5pdL9pk-oW_yyxG3NuC4D9aCAQ@mail.gmail.com>
Subject: Re: Re: Re: [PATCH] mm: memcg: Use larger chunks for proactive reclaim
To: =?UTF-8?Q?Michal_Koutn=C3=BD?= <mkoutny@suse.com>
Cc: Efly Young <yangyifei03@kuaishou.com>, hannes@cmpxchg.org, akpm@linux-foundation.org, 
	android-mm@google.com, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, 
	linux-mm@kvack.org, mhocko@kernel.org, muchun.song@linux.dev, 
	roman.gushchin@linux.dev, shakeelb@google.com, yuzhao@google.com
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On Fri, Feb 2, 2024 at 11:46=E2=80=AFAM Michal Koutn=C3=BD <mkoutny@suse.co=
m> wrote:
>
> On Fri, Feb 02, 2024 at 10:22:34AM -0800, "T.J. Mercier" <tjmercier@googl=
e.com> wrote:
> > So all of these should be more or less equivalent:
> > delta <=3D 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

Ok great, let's do that. Thanks for your input.