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Date:   Sat, 17 Dec 2022 10:57:06 +0100
From:   Michal Hocko <mhocko@suse.com>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Mina Almasry <almasrymina@google.com>, Tejun Heo <tj@kernel.org>,
        Zefan Li <lizefan.x@bytedance.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Roman Gushchin <roman.gushchin@linux.dev>,
        Shakeel Butt <shakeelb@google.com>,
        Muchun Song <songmuchun@bytedance.com>,
        Huang Ying <ying.huang@intel.com>,
        Yang Shi <yang.shi@linux.alibaba.com>,
        Yosry Ahmed <yosryahmed@google.com>, weixugc@google.com,
        fvdl@google.com, bagasdotme@gmail.com, cgroups@vger.kernel.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org
Subject: Re: [PATCH] Revert "mm: add nodes= arg to memory.reclaim"
Message-ID: <Y52Scge3ynvn/mB4@dhcp22.suse.cz>
References: <20221202223533.1785418-1-almasrymina@google.com>
 <Y5bsmpCyeryu3Zz1@dhcp22.suse.cz>
 <Y5xASNe1x8cusiTx@dhcp22.suse.cz>
 <20221216101820.3f4a370af2c93d3c2e78ed8a@linux-foundation.org>
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On Fri 16-12-22 10:18:20, Andrew Morton wrote:
> On Fri, 16 Dec 2022 10:54:16 +0100 Michal Hocko <mhocko@suse.com> wrote:
> 
> > I have noticed that the patch made it into Linus tree already. Can we
> > please revert it because the semantic is not really clear and we should
> > really not create yet another user API maintenance problem.
> 
> Well dang.  I was waiting for the discussion to converge, blissfully
> unaware that the thing was sitting in mm-stable :(  I guess the
> 
> 	Acked-by: Michal Hocko <mhocko@suse.com>
> 	Acked-by: Shakeel Butt <shakeelb@google.com>
> 	Acked-by: Muchun Song <songmuchun@bytedance.com>
> 
> fooled me.

Hmm, as pointed out in http://lkml.kernel.org/r/Y5bsmpCyeryu3Zz1@dhcp22.suse.cz
I've failed to see through all the consequences of the implementation.
SO my bad here to add my ack before fully understanding all the
implications.

> I think it's a bit premature to revert at this stage.  Possibly we can
> get to the desired end state by modifying the existing code.  Possibly
> we can get to the desired end state by reverting this and by adding
> something new.

Sure if we can converge to a proper implementation during the rc phase
then it would be ok. I cannot speak for others but at least for me
upcoming 2 weeks would be mostly offline so I cannot really contribute
much. A revert would be much more easier from the coordination POV IMHO.

Also I do not think there is any strong reason to rush this in. I do not
really see any major problems to have this extension in 6.2

-- 
Michal Hocko
SUSE Labs