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Date:   Wed, 12 Oct 2022 15:23:33 +0200
From:   Michal Hocko <mhocko@suse.com>
To:     Vinicius Petrucci <vpetrucci@gmail.com>
Cc:     Frank van der Linden <fvdl@google.com>,
        Zhongkun He <hezhongkun.hzk@bytedance.com>, corbet@lwn.net,
        akpm@linux-foundation.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
        linux-doc@vger.kernel.org, wuyun.abel@bytedance.com
Subject: Re: [RFC] mm: add new syscall pidfd_set_mempolicy()
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On Wed 12-10-22 15:07:48, Michal Hocko wrote:
> On Wed 12-10-22 07:34:06, Vinicius Petrucci wrote:
[...]
> > Having a feature like "pidfd/process_mbind" would really simplify our
> > user-level agent implementation moving forward, as right now we are
> > adding a LD_PRELOAD wrapper (for signal handler) to listen and execute
> > "mbind" requests from another process. If there's any other
> > alternative solution to this already (via ptrace?), please let me
> > know.
> 
> userfaultfd sounds like the closest match if #PF handling under control
> of an external agent is viable.

And just to clarify. I haven't ever played with using userfaultfd for
numa balancing so I might be completely wrong here.
-- 
Michal Hocko
SUSE Labs