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Subject: Re: [PATCH 0/4] Track exported dma-buffers with memcg
From:   Shakeel Butt <shakeelb@google.com>
To:     "T.J. Mercier" <tjmercier@google.com>
Cc:     Tejun Heo <tj@kernel.org>, Zefan Li <lizefan.x@bytedance.com>,
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On Wed, Jan 11, 2023 at 04:49:36PM -0800, T.J. Mercier wrote:
> 
[...]
> > The problem is a bit that with gpu allocations reclaim is essentially "we
> > pass the error to userspace and they get to sort the mess out". There are
> > some exceptions (some gpu drivers to have shrinkers) would we need to make
> > sure these shrinkers are tied into the cgroup stuff before we could enable
> > charging for them?
> >
> I'm also not sure that we can depend on the dmabuf being backed at
> export time 100% of the time? (They are for dmabuf heaps.) If not,
> that'd make calling the existing memcg folio based functions a bit
> difficult.
> 

Where does the actual memory get allocated? I see the first patch is
updating the stat in dma_buf_export() and dma_buf_release(). Does the
memory get allocated and freed in those code paths?