Re: [PATCH v1 net-next 13/13] net-memcg: Allow decoupling memcg from global protocol memory accounting.

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

On Tue, Jul 22, 2025 at 11:18:40AM -0700, Kuniyuki Iwashima wrote:
> >
> > I expect this state of jobs with different network accounting config
> > running concurrently is temporary while the migrationg from one to other
> > is happening. Please correct me if I am wrong.
> 
> We need to migrate workload gradually and the system-wide config
> does not work at all.  AFAIU, there are already years of effort spent
> on the migration but it's not yet completed at Google.  So, I don't think
> the need is temporary.
> 

From what I remembered shared borg had completely moved to memcg
accounting of network memory (with sys container as an exception) years
ago. Did something change there?

> >
> > My main concern with the memcg knob is that it is permanent and it
> > requires a hierarchical semantics. No need to add a permanent interface
> > for a temporary need and I don't see a clear hierarchical semantic for
> > this interface.
> 
> I don't see merits of having hierarchical semantics for this knob.
> Regardless of this knob, hierarchical semantics is guaranteed
> by other knobs.  I think such semantics for this knob just complicates
> the code with no gain.
> 

Cgroup interfaces are hierarchical and we want to keep it that way.
Putting non-hierarchical interfaces just makes configuration and setup
hard to reason about.

> 
> >
> > I am wondering if alternative approches for per-workload settings are
> > explore starting with BPF.
> >

Any response on the above? Any alternative approaches explored?