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Date:   Fri, 19 Aug 2022 08:32:58 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Muchun Song <songmuchun@bytedance.com>
Cc:     rafael@kernel.org, mike.kravetz@oracle.com,
        akpm@linux-foundation.org, osalvador@suse.de, david@redhat.com,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        muchun.song@linux.dev
Subject: Re: [PATCH] mm: hugetlb: simplify per-node sysfs creation and removal
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References: <20220819052137.7985-1-songmuchun@bytedance.com>
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On Fri, Aug 19, 2022 at 01:21:37PM +0800, Muchun Song wrote:
> The following commit offload per-node sysfs creation and removal to a kworker and
> did not say why it is needed.  And it also said "I don't know that this is
> absolutely required".  It seems like the author was not sure as well.  Since it
> only complicates the code, this patch will revert the changes to simplify the code.
> 
>   39da08cb074c ("hugetlb: offload per node attribute registrations")

Any specific reason why you did not cc: the original author of this
commit, or anyone else on the patch?

> We could use memory hotplug notifier to do per-node sysfs creation and removal
> instead of inserting those operations to node registration and unregistration.
> Then, it can reduce the code coupling between node.c and hugetlb.c.  Also, it can
> simplify the code.

I do not think we had memory hotplug notifier back in 2009 when this
commit was first written.

How did you test this?  Did you use a HUGETLBFS system and verify that
everything still works properly?  You are deleting a lot of code (always
nice), but making sure everything is still operating the same is a good
thing.

thanks,

greg k-h