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 <20211213165342.74704-10-songmuchun@bytedance.com> <YbilqnwnuTiQ2FEB@cmpxchg.org>
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From:   Muchun Song <songmuchun@bytedance.com>
Date:   Wed, 15 Dec 2021 20:36:28 +0800
Message-ID: <CAMZfGtXng-X2LPZ3CHwNuyT6LtnkWcHsd_3FZiQpchwtKhR5JQ@mail.gmail.com>
Subject: Re: [PATCH v4 09/17] mm: workingset: use xas_set_lru() to pass shadow_nodes
To:     Johannes Weiner <hannes@cmpxchg.org>
Cc:     Matthew Wilcox <willy@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Michal Hocko <mhocko@kernel.org>,
        Vladimir Davydov <vdavydov.dev@gmail.com>,
        Shakeel Butt <shakeelb@google.com>,
        Roman Gushchin <guro@fb.com>, Yang Shi <shy828301@gmail.com>,
        Alex Shi <alexs@kernel.org>,
        Wei Yang <richard.weiyang@gmail.com>,
        Dave Chinner <david@fromorbit.com>,
        trond.myklebust@hammerspace.com, anna.schumaker@netapp.com,
        jaegeuk@kernel.org, chao@kernel.org,
        Kari Argillander <kari.argillander@gmail.com>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux Memory Management List <linux-mm@kvack.org>,
        linux-nfs@vger.kernel.org, Qi Zheng <zhengqi.arch@bytedance.com>,
        Xiongchun duan <duanxiongchun@bytedance.com>,
        fam.zheng@bytedance.com, Muchun Song <smuchun@gmail.com>
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On Tue, Dec 14, 2021 at 10:09 PM Johannes Weiner <hannes@cmpxchg.org> wrote:
>
> On Tue, Dec 14, 2021 at 12:53:34AM +0800, Muchun Song wrote:
> > The workingset will add the xa_node to shadow_nodes, so we should use
> > xas_set_lru() to pass the list_lru which we want to insert xa_node
> > into to set up the xa_node reclaim context correctly.
> >
> > Signed-off-by: Muchun Song <songmuchun@bytedance.com>
>
> Ah, you can't instantiate the list on-demand in list_lru_add() because
> that's happening in an atomic context. So you need the lru available
> in the broader xa update context and group the lru setup in with the
> other pre-atomic node allocation bits. Fair enough. I think it would
> be a bit easier to read if this patch and the previous one were
> squashed (workingset is the only user of xa_lru anyway) and you added
> that explanation. But other than that, the changes make sense to me;
> to a combined patch, please add:
>

Great. I'll do it. Thanks for your review.

> Acked-by: Johannes Weiner <hannes@cmpxchg.org>