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Message-ID: <b1fe7b84-6d27-e42e-4c89-b5ac5f648c4b@linux.alibaba.com>
Date:   Tue, 3 May 2022 10:20:03 +0800
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Subject: Re: [PATCH 2/3] mm/damon/sysfs: support fixed virtual address ranges
 monitoring
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To:     SeongJae Park <sj@kernel.org>
Cc:     akpm@linux-foundation.org, linux-damon@amazon.com,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
References: <20220502161810.134199-1-sj@kernel.org>
From:   Rongwei Wang <rongwei.wang@linux.alibaba.com>
In-Reply-To: <20220502161810.134199-1-sj@kernel.org>
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On 5/3/22 12:18 AM, SeongJae Park wrote:
> Hi Rongwei,
> 
> On Mon, 2 May 2022 15:56:58 +0800 Rongwei Wang <rongwei.wang@linux.alibaba.com> wrote:
> 
>> Hi, SeongJae
>>
>> I had read and tested your patchset these days. It works.
> 
> Thank you for the tests! :D
> 
>> It seems that these patches only fix the issue about init_regions in
>> DAMON-sysfs, but not fix in DAMON-dbgfs? maybe I missing something.
>>
>> If so, do you have any plan to fix this bug in dbgfs? Actually, what I
>> want to say is that I ready a patch for solving the init_regions related
>> bug in dbgfs these days. I not sure if you're interested in it.
> 
> The plan is to freeze DAMON debugfs interface after DAMON sysfs interface is
> merged, and then entirely remove it after next LTS kernel.  It was mentioned in
> the sysfs interface patchset as below:
> https://lore.kernel.org/linux-mm/20220228081314.5770-1-sj@kernel.org/
> 
>      Future Plan of DAMON_DBGFS Deprecation
>      ======================================
>      
>      Once this patchset is merged, DAMON_DBGFS development will be frozen.  That is,
>      we will maintain it to work as is now so that no users will be break.  But, it
>      will not be extended to provide any new feature of DAMON.  The support will be
>      continued only until next LTS release.  After that, we will drop DAMON_DBGFS.
> 
> The plan was also shared in the kernel doc as below[1], but maybe it was too
> small to read, or ambiguous.  Sorry if it was the case.
> 
>      debugfs interface. This is almost identical to sysfs interface. This will
>      be _removed_ after next LTS kernel is released, so users should move to the
>      sysfs interface.
Hi, SeongJae

Thanks, for telling me the doc!
It seems that I have to update my datop. New sysfs interface has changed 
too much.

Anyway, Thanks! :)

> 
> [1] https://docs.kernel.org/admin-guide/mm/damon/usage.html#debugfs-interface
> 
> So, I don't have a big interest at extending DAMON debugfs for fvaddr.  That
> said, of course we could discuss more if you really need it.  If so, please let
> me know.
> 
> 
> Thanks,
> SJ
> 
>>
>> Best Regards,
>> Rongwei
>>