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From:   Yu Zhao <yuzhao@google.com>
Date:   Thu, 22 Dec 2022 12:52:07 -0700
Message-ID: <CAOUHufYN8UPHrsni5fohOUK4=Od8Ny312CJrKvHjou=Zxj=+DQ@mail.gmail.com>
Subject: Re: [PATCH 1/2] mm: add vma_has_locality()
To:     Yuanchu Xie <yuanchu@google.com>
Cc:     Ivan Babrou <ivan@cloudflare.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Andrew Morton <akpm@linux-foundation.org>,
        Steven Barrett <steven@liquorix.net>,
        Brian Geffon <bgeffon@google.com>,
        Oleksandr Natalenko <oleksandr@natalenko.name>,
        Suren Baghdasaryan <surenb@google.com>,
        Arnd Bergmann <arnd@arndb.de>, Peter Xu <peterx@redhat.com>,
        Hugh Dickins <hughd@google.com>,
        Gaosheng Cui <cuigaosheng1@huawei.com>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org
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On Wed, Dec 21, 2022 at 11:13 PM Yuanchu Xie <yuanchu@google.com> wrote:
>
> From: Yu Zhao <yuzhao@google.com>
>
> Currently in vm_flags in vm_area_struct, both VM_SEQ_READ and
> VM_RAND_READ indicate a lack of locality in accesses to the vma. Some
> places that check for locality are missing one of them. We add
> vma_has_locality to replace the existing locality checks for clarity.

Need benchmark results. A simple fio test will do; doesn't need to be
the curl one.

> +       /*
> +        * If we are reclaiming on behalf of a cgroup, skip counting on behalf
> +        * of references from different cgroups

Nit: add a period at the end.

> @@ -906,6 +908,7 @@ int folio_referenced(struct folio *folio, int is_locked,
>                 .arg = (void *)&pra,
>                 .anon_lock = folio_lock_anon_vma_read,
>                 .try_lock = true,
> +               .invalid_vma = invalid_folio_referenced_vma,

Nice. (What I suggested isn't as clean:
https://lore.kernel.org/all/Y31s%2FK8T85jh05wH@google.com/)