From mboxrd@z Thu Jan  1 00:00:00 1970
From: Shakeel Butt <shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH] memcg: remove unused mem_cgroup_from_obj()
Date: Mon, 29 May 2023 18:53:37 +0000
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To: Matthew Wilcox <willy-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
Cc: Muchun Song <muchun.song-fxUVXftIFDnyG1zEObXtfA@public.gmane.org>, Yosry Ahmed <yosryahmed-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, Miaohe Lin <linmiaohe-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>, Vasily Averin <vasily.averin-fxUVXftIFDnyG1zEObXtfA@public.gmane.org>, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, roman.gushchin-fxUVXftIFDnyG1zEObXtfA@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org

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().