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Date:   Tue, 22 Nov 2022 16:33:09 +0800
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Subject: Re: [External] Re: [PATCH v2] mm: add new syscall
 pidfd_set_mempolicy().
To:     Michal Hocko <mhocko@suse.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>, corbet@lwn.net,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        linux-api@vger.kernel.org, linux-doc@vger.kernel.org
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From:   Zhongkun He <hezhongkun.hzk@bytedance.com>
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Hi Michal, thanks for your replay and suggestions.

> 
> Yes the memory consumption is going to increase but the question is
> whether this is something that is a real problem. Is it really common to
> have many vmas with a dedicated policy?

Yes, it does not a realy problem.

> 
> What I am arguing here is that there are essentially 2 ways forward.
> Either we continue to build up on top of the existing and arguably very
> fragile code and make it even more subtle or follow a general pattern of
> a proper reference counting (with usual tricks to reduce cache line
> bouncing and similar issues). I do not really see why memory policies
> should be any different and require very special treatment.
> 

I got it. It is rather subtle and easy to get wrong if we push forward
with the existing way and it is a good opportunity to get from the
existing subtle model. I will try that on next version.

__
Best Regards,
Zhongkun