Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <36e3df6c-0f70-96e5-51e2-55870b134713@bytedance.com>
Date:   Sun, 15 Jan 2023 00:10:17 +0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Thunderbird/102.6.0
Subject: Re: [External] Re: [PATCH 0/3] mm: replace atomic_t with percpu_ref
 in mempolicy.
To:     Michal Hocko <mhocko@suse.com>
Cc:     akpm@linux-foundation.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
        wuyun.abel@bytedance.com
References: <20221204161432.2149375-1-hezhongkun.hzk@bytedance.com>
 <Y8GE1r9/c1DHsHj0@dhcp22.suse.cz> <Y8GFUiSih8f0mUoU@dhcp22.suse.cz>
From:   Zhongkun He <hezhongkun.hzk@bytedance.com>
In-Reply-To: <Y8GFUiSih8f0mUoU@dhcp22.suse.cz>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

> On Fri 13-01-23 17:20:39, Michal Hocko wrote:
>>
>> This is really hard to follow. Without having the context from previous
>> discussions I would be completely lost. Please structure your cover
>> letter but also other patch in general in the form:
>> - what is the problem you would like to deal with
>> 	- want to introduce pidfd_set_mempolicy because XYZ
>> - what stands in the way
>> 	- mempolicy objects access constrains (reliance on operating in
>> 	  the current context)
>> 	- reference counting needs to be unconditional
>> 	- why regular reference counting is not sufficient (performance)
>> - what is this patchset proposing
>> 	- per cpu reference counting
>> 	- how is it implemented
>> - how is the patch series structured
>> 	- make the reference counting unconditional
>> 	- special case static (never released) policies
>> 	- replace standard ref counting by per-cpu reference counting
> 	- introduce pidfd_set_mempolicy
>> - how has this been tested?

Hi Michal, thanks for your review and suggestions.

I will follow the advice above to structure the letter and
split the patches smaller on next version.

Thanks.