Re: [PATCH 07/16] memcg: add support for GPU page counters. (v4)

[Shakeel Butt <shakeel.butt@linux.dev>]

+TJ

On Mon, Mar 02, 2026 at 03:37:37PM +0100, Christian König wrote:
> On 3/2/26 15:15, Shakeel Butt wrote:
> > On Wed, Feb 25, 2026 at 10:09:55AM +0100, Christian König wrote:
> >> On 2/24/26 20:28, Dave Airlie wrote:
> > [...]
> >>
> >>> This has been a pain in the ass for desktop for years, and I'd like to
> >>> fix it, the HPC use case if purely a driver for me doing the work.
> >>
> >> Wait a second. How does accounting to cgroups help with that in any way?
> >>
> >> The last time I looked into this problem the OOM killer worked based on the per task_struct stats which couldn't be influenced this way.
> >>
> > 
> > It depends on the context of the oom-killer. If the oom-killer is triggered due
> > to memcg limits then only the processes in the scope of the memcg will be
> > targetted by the oom-killer. With the specific setting, the oom-killer can kill
> > all the processes in the target memcg.
> > 
> > However nowadays the userspace oom-killer is preferred over the kernel
> > oom-killer due to flexibility and configurability. Userspace oom-killers like
> > systmd-oomd, Android's LMKD or fb-oomd are being used in containerized
> > environments. Such oom-killers looks at memcg stats and hiding something
> > something from memcg i.e. not charging to memcg will hide such usage from these
> > oom-killers.
> 
> Well exactly that's the problem. Android's oom killer is *not* using memcg exactly because of this inflexibility.

Are you sure Android's oom killer is not using memcg? From what I see in the
documentation [1], it requires memcg.

[1] https://source.android.com/docs/core/perf/lmkd

> 
> See the multiple iterations we already had on that topic. Even including reverting already upstream uAPI.
> 
> The latest incarnation is that BPF is used for this task on Android.
> 
> Regards,
> Christian.