Re: drm/ttm/memcg/lru: enable memcg tracking for ttm, xe and amdgpu driver (part 2) (v2).

["Thomas Hellström" <thomas.hellstrom@linux.intel.com>]

Hi, Dave,

On Mon, 2026-07-06 at 15:22 +1000, Dave Airlie wrote:
> This is just a repost with a number of sashiko identified problems
> that I fixed.
> 
> I committed the vmstat counters and list lru changes, and they are
> now in tree.
> 
> This is the remainder of this series. Intel have expressed interest
> in getting
> this landed for xe, we can drop the amdgpu changes for now if they
> can't get
> across the line.
> 
> I've dropped all previous acks/reviews.
> 
> This series adds the memcg counters for GPU active and GPU reclaim to
> align
> with the two global vmstats. It adds an accounting flag to TTM
> alloc/populate,
> and enables memcg tracking and shrinker support in TTM.
> 
> Then it adds amdgpu and xe support.
> 
> I think for this to land, Christian holds the main objection which I
> still fail
> to fully understand beyond it doesn't solve all the problems we ever
> have had
> with cgroups and drm, so we shouldn't even bother, and maybe we could
> do it at
> the object level, and integrated with dmem, and android cross process
> accounting,
> but I still feel this is a good baseline.
> 
> I think this is the right layer to hook this into TTM, where we
> allocate memory
> and I think accounting for this memory in a proper way should be
> done.
> 
> Intel folks (Thomas/Maarten) please review and express concerns as
> well.

Some questions about the design that might belong in the cover-letter.

- First, Since from my understanding gpu shmem allocations are charged
against memcg, (i915 igfx and to some extent dgfx), I think this makes
sense, although it would be good to have an outlook:

1) What about system memory allocations targeting suspend / hibernate
evictions, will they be charged against the root cgroup?

2) Plan for limits on total gpu pages / pinned gpu pages? Is dmemcg a
fit for such limits (coexisting with memcg) or should such limits be
implemented in memcg?

3) IIRC I noticed a patch for dma-heaps where dmemcg was suggested for
android, since it separates GPU memory and system memory. Do we plan
simething similar here, based on config options?

Thanks,
Thomas


> 
> Regards,
> Dave.