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Date:   Mon, 26 Sep 2022 20:53:19 +0800
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Subject: Re: [External] Re: [RFC] proc: Add a new isolated /proc/pid/mempolicy
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To:     Michal Hocko <mhocko@suse.com>
Cc:     corbet@lwn.net, akpm@linux-foundation.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
        wuyun.abel@bytedance.com
References: <20220926091033.340-1-hezhongkun.hzk@bytedance.com>
 <YzF3aaLvEvFhTQa3@dhcp22.suse.cz>
From:   Zhongkun He <hezhongkun.hzk@bytedance.com>
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> [Cc linux-api - please do so for any patches making/updating
> kernel<->user interfaces]
> 
> 
> On Mon 26-09-22 17:10:33, hezhongkun wrote:
>> From: Zhongkun He <hezhongkun.hzk@bytedance.com>
>>
>> /proc/pid/mempolicy can be used to check and adjust the userspace task's
>> mempolicy dynamically.In many case, the application and the control plane
>> are two separate systems. When the application is created, it doesn't know
>> how to use memory, and it doesn't care. The control plane will decide the
>> memory usage policy based on different reasons.In that case, we can
>> dynamically adjust the mempolicy using /proc/pid/mempolicy interface.
> 
> Is there any reason to make it procfs interface rather than pidfd one?

Hi michal,  thanks for your reply.

I just think that it is easy to display and adjust the mempolicy using 
procfs. But it may not be suitable, I will send a pidfd_set_mempolicy 
patch later.

Btw.in order to add per-thread-group mempolicy, is it possible to add 
mempolicy in mm_struct?