Sender: Tejun Heo <htejun@gmail.com>
Date:   Tue, 21 Feb 2023 07:29:18 -1000
From:   Tejun Heo <tj@kernel.org>
To:     Jason Gunthorpe <jgg@nvidia.com>
Cc:     Michal Hocko <mhocko@suse.com>,
        Yosry Ahmed <yosryahmed@google.com>,
        Alistair Popple <apopple@nvidia.com>, linux-mm@kvack.org,
        cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
        jhubbard@nvidia.com, tjmercier@google.com, hannes@cmpxchg.org,
        surenb@google.com, mkoutny@suse.com, daniel@ffwll.ch,
        "Daniel P . Berrange" <berrange@redhat.com>,
        Alex Williamson <alex.williamson@redhat.com>,
        Zefan Li <lizefan.x@bytedance.com>,
        Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 14/19] mm: Introduce a cgroup for pinned memory
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On Tue, Feb 21, 2023 at 01:25:59PM -0400, Jason Gunthorpe wrote:
> On Tue, Feb 21, 2023 at 06:51:48AM -1000, Tejun Heo wrote:
> > cgroup, right? It makes little sense to me to separate the owner of the
> > memory page and the pinner of it. They should be one and the same.
> 
> The owner and pinner are not always the same entity or we could just
> use the page's cgroup.

Yeah, so, what I'm trying to say is that that might be the source of the
problem. Is the current page ownership attribution correct given that the fd
for whatever reason is determining the pinning ownership or should the page
ownership be attributed the same way too? If they indeed need to differ,
that probably would need pretty strong justifications.

Thanks.

-- 
tejun