Re: [RFC 0/1] Try to add memory allocation info for cgroup oom kill

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

On Thu, Aug 21, 2025 at 12:18:00PM -0700, Yueyang Pan wrote:
> On Thu, Aug 21, 2025 at 11:35:19AM -0700, Shakeel Butt wrote:
> > On Thu, Aug 14, 2025 at 10:11:56AM -0700, Yueyang Pan wrote:
> > > Right now in the oom_kill_process if the oom is because of the cgroup 
> > > limit, we won't get memory allocation infomation. In some cases, we 
> > > can have a large cgroup workload running which dominates the machine. 
> > > The reason using cgroup is to leave some resource for system. When this 
> > > cgroup is killed, we would also like to have some memory allocation 
> > > information for the whole server as well. This is reason behind this 
> > > mini change. Is it an acceptable thing to do? Will it be too much 
> > > information for people? I am happy with any suggestions!
> > 
> > For a single patch, it is better to have all the context in the patch
> > and there is no need for cover letter.
> 
> Thanks for your suggestion Shakeel! I will change this in the next version.
> 
> > 
> > What exact information you want on the memcg oom that will be helpful
> > for the users in general? You mentioned memory allocation information,
> > can you please elaborate a bit more.
> > 
> 
> As in my reply to Suren, I was thinking the system-wide memory usage info 
> provided by show_free_pages and memory allocation profiling info can help 
> us debug cgoom by comparing them with historical data. What is your take on 
> this?
> 

I am not really sure about show_free_areas(). More specifically how the
historical data diff will be useful for a memcg oom. If you have a
concrete example, please give one. For memory allocation profiling, is
it possible to filter for the given memcg? Do we save memcg information
in the memory allocation profiling?