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Date:   Wed, 4 Oct 2023 11:02:11 +0200
From:   Michal =?utf-8?Q?Koutn=C3=BD?= <mkoutny@suse.com>
To:     Yosry Ahmed <yosryahmed@google.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Shakeel Butt <shakeelb@google.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Michal Hocko <mhocko@kernel.org>,
        Roman Gushchin <roman.gushchin@linux.dev>,
        Muchun Song <muchun.song@linux.dev>, linux-mm@kvack.org,
        cgroups@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/2] mm: memcg: refactor page state unit helpers
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On Tue, Oct 03, 2023 at 12:47:25PM -0700, Yosry Ahmed <yosryahmed@google.com> wrote:
> Those constants are shared with code outside of memcg, namely enum
> node_stat_item and enum vm_event_item, and IIUC they are used
> differently outside of memcg. Did I miss something?

The difference is not big, e.g.
  mod_lruvec_state(lruvec, WORKINGSET_ACTIVATE_BASE + type, delta);
could be
  __count_memcg_events(
    container_of(lruvec, struct mem_cgroup_per_node, lruvec)->memcg,
    WORKINGSET_ACTIVATE_BASE + type, delta
  );

Yes, it would mean transferring WORKINGSET_* items from enum
node_stat_item to enum vm_event_item.
IOW, I don't know what is the effective difference between
mod_memcg_lruvec_state() and count_memcg_events().
Is it per-memcg vs per-memcg-per-node resolution?
(Is _that_ read by workingset mechanism?)

Thanks,
Michal

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