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Date:   Mon, 29 May 2023 18:53:37 +0000
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Message-ID: <20230529185337.3gk3ww76sdxdgv6o@google.com>
Subject: Re: [PATCH] memcg: remove unused mem_cgroup_from_obj()
From:   Shakeel Butt <shakeelb@google.com>
To:     Matthew Wilcox <willy@infradead.org>
Cc:     Muchun Song <muchun.song@linux.dev>,
        Yosry Ahmed <yosryahmed@google.com>,
        Miaohe Lin <linmiaohe@huawei.com>,
        Vasily Averin <vasily.averin@linux.dev>, hannes@cmpxchg.org,
        mhocko@kernel.org, roman.gushchin@linux.dev,
        akpm@linux-foundation.org, cgroups@vger.kernel.org,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
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On Sun, May 28, 2023 at 08:36:43PM +0100, Matthew Wilcox wrote:
> On Sun, May 28, 2023 at 09:01:37PM +0800, Muchun Song wrote:
> > with *init_net*. If Vasily does not want to bring commit 1d0403d20f6c back,
> > this patch LGTM. Otherwise, let's wait for Vasily.
> 
> If we're not going to bring back 1d0403d20f6c then we should
> simply revert fc4db90fe71e instead of applying this patch.

Initially I was thinking of adding virt_addr_valid() check in the
mem_cgroup_from_obj() but it seems like that check is not cheap on
arm64. I don't have any quick solutions other than adding a check
against init_net in __register_pernet_operations(). I will wait for
couple of days for Vasily otherwise I will retry 1d0403d20f6c with the
init_net check in __register_pernet_operations().